64 results on '"Okke Batelaan"'
Search Results
2. A new approach to quantification of groundwater resource stress
- Author
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Mehri Tabarmayeh, Mehdi Zarei, and Okke Batelaan
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Groundwater ,Stress indicators ,Water security ,Sustainable use ,Physical geography ,GB3-5030 ,Geology ,QE1-996.5 - Abstract
Study region: Mond basin, comprising 61 aquifers in southern Iran. Study focus: New indicators and a framework are presented for quantifying the intensity of groundwater stress by considering hydrogeological and anthropogenic factors, including renewable water availability, non-renewable water storage, withdrawal, and return flow. In contrast to existing methods, our proposed indicators consider accumulated historical water stress tolerated by an aquifer during an exploitation period and incorporate groundwater over-extraction from both renewable and non-renewable storages of aquifers. New hydrological insights: We assessed the applicability of existing and newly defined groundwater stress indicators on the Mond aquifers. Our results indicate that the proposed approach is able to inform the degree of groundwater stress and identify vulnerable aquifers with high intensity of groundwater stress. Statistical analysis of long-term mean annual groundwater drawdown and groundwater storage confirmed the results of aquifer classification in terms of intensity of groundwater stress. Finally, the response of aquifers in different stages of water stress was evaluated by scenarios of i) reduced human-induced withdrawal and irrigation return flow and ii) increasing recharge. These scenario analyses indicate that even up to a 50% reduction in human water use or a 50% increase in recharge does not recover the more severely stressed aquifers to sustainable hydrologic conditions.
- Published
- 2022
- Full Text
- View/download PDF
3. Cooperation in hydrogeophysics: Enhancing practitioners and institutions’ groundwater assessment capacity, Vientiane Plain, Lao PDR
- Author
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Ounakone Xayviliya, Viengthong Xayavong, Somphasith Douangsavanh, Sounthone Singsoupho, Mathieu Viossanges, Paul Pavelic, Eddie W. Banks, Sinxay Vongphachanh, Okke Batelaan, and Michael Hatch
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geography ,Geophysics ,geography.geographical_feature_category ,Floodplain ,Geochemistry and Petrology ,Hydrogeophysics ,Environmental science ,Water resource management ,Groundwater ,Water scarcity - Abstract
The lowland floodplains of the Lao People’s Democratic Republic (PDR) experience prolonged dry seasons characterized by pronounced and common water scarcity, with water supplies increasingly offset with groundwater. Groundwater assessment is still at a very rudimentary stage in Laos, making it difficult to ensure that new water supplies are developed successfully and managed sustainably. The goal of this study is to apply a variety of field hydrogeophysical techniques to this problem and in the process help build and strengthen human and institutional capacity with various stakeholder groups from the government, the university, and the community. The study area focuses on a cross section of the Vientiane Plain (VP) in the Lower Mekong Basin in central Lao PDR to identify and characterize the hydrogeology and groundwater quality. The research collaboration has built and strengthened stakeholder capacity by developing and progressing the hydrogeologic field mapping of the VP. It has provided local undergraduate and postgraduate training opportunities using several different near-surface geophysical and hydrogeologic techniques, some previously untested in Lao PDR. At one of the survey sites, the geophysics has indicated the spatial extent of the shallow aquifer and in the process identified an extensive conductive zone, interpreted as more saline groundwater. Any groundwater development within this or similar zones is likely to be unsuitable as sources for drinking and irrigation water. Engagement with the local village authorities has supported local community members and government to expand groundwater development for rural water supplies. Access to groundwater as a reliable, safe, and secure resource provides an opportunity for strengthening the resilience of farmers to changing climatic conditions. Participatory research collaboration of this kind can positively enhance data and build capacity, which is a required precursor for improving knowledge and management of poorly understood groundwater resources.
- Published
- 2021
4. Identifying recharge under subtle ephemeral features in a flat-lying semi-arid region using a combined geophysical approach
- Author
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Okke Batelaan, Sylvain Pasquet, B. A. Flinchum, Luk Peeters, Eddie W. Banks, and Michael Hatch
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lcsh:GE1-350 ,Hydrogeology ,Electromagnetics ,Feature (archaeology) ,Water table ,lcsh:T ,Ephemeral key ,0208 environmental biotechnology ,lcsh:Geography. Anthropology. Recreation ,02 engineering and technology ,Geophysics ,Groundwater recharge ,010502 geochemistry & geophysics ,01 natural sciences ,lcsh:Technology ,lcsh:TD1-1066 ,020801 environmental engineering ,lcsh:G ,lcsh:Environmental technology. Sanitary engineering ,Surface water ,Geology ,Groundwater ,lcsh:Environmental sciences ,0105 earth and related environmental sciences - Abstract
Identifying and quantifying recharge processes linked to ephemeral surface water features is challenging due to their episodic nature. We use a combination of well-established near-surface geophysical methods to provide evidence of a surface and groundwater connection under a small ephemeral recharge feature in a flat, semi-arid region near Adelaide, Australia. We use a seismic survey to obtain P-wave velocity through travel-time tomography and S-wave velocity through the multichannel analysis of surface waves. The ratios between P-wave and S-wave velocities are used to calculate Poisson's ratio, which allow us to infer the position of the water table. Separate geophysical surveys were used to obtain electrical conductivity measurements from time-domain electromagnetics and water contents from downhole nuclear magnetic resonance. The geophysical observations provide evidence to support a groundwater mound underneath a subtle ephemeral surface water feature. Our results suggest that recharge is localized and that small-scale ephemeral features may play an important role in groundwater recharge. Furthermore, we show that a combined geophysical approach can provide a perspective that helps shape the hydrogeological conceptualization of a semi-arid region.
- Published
- 2020
5. Geophysics used to help find good quality groundwater in the Vientiane Plain, Lao PDR
- Author
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Somphasith Douangsavanh, Okke Batelaan, Eddie W. Banks, and Michael Hatch
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Electromagnetics ,business.industry ,media_common.quotation_subject ,General Engineering ,Hydrogeophysics ,Agriculture ,Environmental science ,Quality (business) ,Water quality ,Agricultural productivity ,Water resource management ,business ,Rural population ,Groundwater ,media_common - Abstract
Lao PDR is a poorly developed country, with a large rural population which relies heavily on agricultural production. The Vientiane Plain is one of the most important and largest agricultural produ...
- Published
- 2019
6. Mapping catchment-scale unmonitored groundwater abstractions: Approaches based on soft data
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Daniel Partington, Margaret Shanafield, T.T. Nhat, Okke Batelaan, and H.M. Vu
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Irrigation ,010504 meteorology & atmospheric sciences ,Industrial production ,0207 environmental engineering ,Drainage basin ,02 engineering and technology ,Groundwater abstraction ,01 natural sciences ,Domestic consumption ,Earth and Planetary Sciences (miscellaneous) ,020701 environmental engineering ,lcsh:Physical geography ,0105 earth and related environmental sciences ,Water Science and Technology ,Estimation ,geography ,geography.geographical_feature_category ,Land use ,business.industry ,lcsh:QE1-996.5 ,lcsh:Geology ,Soft data ,Agriculture ,Environmental science ,business ,Water resource management ,lcsh:GB3-5030 ,Cropping ,Groundwater - Abstract
Study region The ungauged, agriculturally dominated La Vi River Basin, Vietnam. Study focus Groundwater abstraction for food and industrial production is increasing globally, putting pressure on groundwater resources and associated ecosystems. In many countries, monitoring of abstraction is poorly organised, resulting in a paucity of data, particularly in developing regions. Therefore, alternative approaches to estimate groundwater withdrawals are necessary. In this study, two soft-data approaches for indirect catchment-scale groundwater abstraction estimation are developed using: (1) local knowledge through a qualitative field survey of groundwater level fluctuations and groundwater withdrawals, and (2) land use data combined with local knowledge on cropping and irrigation practices. New hydrological insights for the region The approaches are tested and applied for the La Vi River Basin, for the 2016 dry season. Total dry season estimated abstractions of 31.07 × 106 m3 and 36.19 × 106 m3 resulted from the two approaches. The advantage of the second approach is the spatial distribution of the estimated groundwater abstraction, aligning highly intensive abstractions with intensive agricultural areas. Despite high uncertainty in both estimates, this quantitative estimate gives valuable information for water managers, and the relatively good agreement between the methods provides trust in the estimates. The approaches are cost-effective and computationally simple solutions for estimating groundwater abstraction in data-poor regions.
- Published
- 2020
7. Analytical and Numerical Groundwater Flow Solutions for the FEMME-Modeling Environment
- Author
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Getachew Adem Mohammed, Mustafa El-Rawy, Kerst Buis, Wouter Zijl, Christian Anibas, Ali Salem, and Okke Batelaan
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River ecosystem ,010504 meteorology & atmospheric sciences ,Groundwater flow ,0207 environmental engineering ,Aquifer ,02 engineering and technology ,Oceanography ,01 natural sciences ,River water ,numerical ,MODFLOW ,020701 environmental engineering ,lcsh:Science ,Biology ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Earth-Surface Processes ,Water Science and Technology ,geography ,geography.geographical_feature_category ,Petroleum engineering ,groundwater-surface water interaction ,Water level ,STRIVE ,FEMME ,Environmental science ,analytical ,lcsh:Q ,Groundwater model ,Groundwater - Abstract
Simple analytical and numerical solutions for confined and unconfined groundwater-surface water interaction in one and two dimensions were developed in the STRIVE package (stream river ecosystem) as part of FEMME (flexible environment for mathematically modelling the environment). Analytical and numerical solutions for interaction between one-dimensional confined and unconfined aquifers and rivers were used to study the effects of a 0.5 m sudden rise in the river water level for 24 h. Furthermore, a two-dimensional groundwater model for an unconfined aquifer was developed and coupled with a one-dimensional hydrodynamic model. This model was applied on a 1 km long reach of the Aa River, Belgium. Two different types of river water level conditions were tested. A MODFLOW model was set up for these different types of water level condition in order to compare the results with the models implemented in STRIVE. The results of the analytical solutions for confined and unconfined aquifers were in good agreement with the numerical results. The results of the two-dimensional groundwater model developed in STRIVE also showed that there is a good agreement with the MODFLOW solutions. It is concluded that the facilities of STRIVE can be used to improve the understanding of groundwater-surface water interaction and to couple the groundwater module with other modules developed for STRIVE. With these new models STRIVE proves to be a powerful example as a development and testing environment for integrated water modeling.
- Published
- 2020
8. Assessment of groundwater resource vulnerability to over-exploitation in a tropical, agricultural basin
- Author
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Manh Hai Vu, Margaret Shanafield, Okke Batelaan, and Daniel Partington
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Overexploitation ,Resource (biology) ,Agriculture ,business.industry ,Vulnerability ,Environmental science ,Structural basin ,Water resource management ,business ,Groundwater - Abstract
In many parts of the world, groundwater extraction for agriculture is strongly increasing, causing severe stress on groundwater resources and associated ecosystems. Understanding how groundwater flow systems support extractions is therefore essential. However, particularly in developing, rural, tropical regions, monitoring of groundwater levels, chemistry and extractions is poorly regulated, resulting in a lack of data. Hence, alternative approaches are necessary to develop best management practices in these groundwater basins. In this study, catchment-scale groundwater extraction is indirectly estimated by two “soft data” approaches: (1) using local knowledge through a qualitative field survey of groundwater level fluctuations and groundwater withdrawals; and (2) land-use/population data combined with local knowledge on cropping/water use practices. Spatially distributed recharge is simulated on the basis of a monthly water balance model, which requires widely available topographic, soil, land-use and meteorological data. Extractions and recharge force a simple, basin-scale groundwater model for assessment of impact of irrigation practices. Agricultural scenarios are developed and modelling procedures are designed to test the temporal and spatial vulnerability over a 100 yr time span of the groundwater resource. The approaches are tested and applied for the agricultural La Vi River basin, Vietnam, where the livelihood of the local farmers requires development of new agricultural and hydrological techniques. The typical cash-crops are cultivated on sandy soils and irrigated in the dry season from thousands of private shallow wells. The tropical climate and strong seasonal rainfall pattern produces a strong fluctuation in groundwater levels. The modelling shows significant spatio-temporal unmet pumping demand dependent on the agricultural development scenario, indicating the need and opportunity for planning of groundwater based irrigation development. Overall, the multi-method comprehensive approach supports basin-scale sustainable groundwater resource development and only requires relatively easily accessible data.
- Published
- 2020
9. Review of Hydrogeology: Groundwater Science and Engineering by Alain DassarguesCRC Press, Boca Raton, FL; 2018; ISBN 9781498744003; 472 pp.; $99.95
- Author
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Luk Peeters and Okke Batelaan
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Hydrogeology ,Science and engineering ,Environmental Chemistry ,Water resource management ,Groundwater ,Geology ,General Environmental Science ,Water Science and Technology ,Civil and Structural Engineering - Published
- 2020
10. Delineation of spatial-temporal patterns of groundwater/surface-water interaction along a river reach (Aa River, Belgium) with transient thermal modeling
- Author
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Jiri Nossent, Uwe Schneidewind, Gert Ghysels, Abebe Debele Tolche, Christian Anibas, Okke Batelaan, Marijke Huysmans, Earth System Sciences, Faculty of Engineering, and Hydrology and Hydraulic Engineering
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Hydrology ,geography ,Hydrogeology ,geography.geographical_feature_category ,0208 environmental biotechnology ,Flow (psychology) ,02 engineering and technology ,020801 environmental engineering ,TRACER ,Thermal ,Spring (hydrology) ,Earth and Planetary Sciences (miscellaneous) ,Environmental science ,Surface water ,Bank ,Groundwater ,Water Science and Technology - Abstract
Among the advances made in analytical and numerical analysis methods to quantify groundwater/surface-water interaction, one methodology that stands out is the use of heat as an environmental tracer. A large data set of river and riverbed temperature profiles from the Aa River in Belgium has been used to examine the spatial-temporal variations of groundwater/surface-water interaction. Exchange fluxes were calculated with the numerical heat-transport code STRIVE. The code was applied in transient mode to overcome previous limitations of steady-state analysis, and allowed for the calculation of model quality. In autumn and winter the mean exchange fluxes reached −90 mm d−1, while in spring and early summer fluxes were −42 mm d−1. Predominantly gaining conditions occurred along the river reach; however, in a few areas the direction of flow changed in time. The river banks showed elevated fluxes up to a factor of 3 compared to the center of the river. Higher fluxes were detected in the upstream section of the reach. Due to the influence of exchange fluxes along the river banks, larger temporal variations were found in the downstream section. The exchange fluxes at the river banks seemed more driven by variable local exchange flows, while the center of the river was dominated by deep and steady regional groundwater flows. These spatial and temporal differences in groundwater/surface-water exchange show the importance of long-term investigations on the driving forces of hyporheic processes across different scales.
- Published
- 2017
11. Groundwater residence time and aquifer recharge in multilayered, semi-confined and faulted aquifer systems using environmental tracers
- Author
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Jordi Batlle-Aguilar, Rolf Kipfer, Matthias S. Brennwald, Okke Batelaan, Eddie W. Banks, and Peter G. Cook
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geography ,geography.geographical_feature_category ,Groundwater flow ,Bedrock ,0208 environmental biotechnology ,Aquifer ,02 engineering and technology ,Groundwater recharge ,020801 environmental engineering ,Depression-focused recharge ,Groundwater discharge ,Petrology ,Groundwater model ,Geomorphology ,Groundwater ,Geology ,Water Science and Technology - Abstract
The potential of environmental tracers (δ18O, δ2H, δ13C, 14C, 4He, 20Ne, 40Ar, N2) to assist our understanding of recharge processes, groundwater flow velocities and residence times in semi-confined, multilayered and faulted aquifer systems was tested in a coastal system with Quaternary sediments overlying Tertiary aquifers and fractured bedrock. Carbon-14 groundwater ages were found to increase with depth and distance ( 30,000 y near the coast), confirming that the system is semi-confined and the palaeometeoric origin of groundwater as suggested by water stable isotopes. The presence of old groundwater near the top of deep semi-confined aquifers suggests that recharge mainly occurs in the ranges east of the basin. This is also supported by Cl concentrations, which are higher in the overlying Quaternary aquifers. Groundwater flow velocities between 0.3 and 1.8 m y−1 were estimated using 14C ages, resulting in basin recharge estimates between 0.3 × 107 and 2 × 107 m3 y−1. Radiocarbon and 4He-estimated flow velocities were generally in good agreement, although 4He accumulation rates ranging between 8 × 10−12 and 1 × 10−10 cm3 STP g−1 y−1 and 1.7–7.1 × 10−7 cm3 STP g−1 km−1 confirmed slower flow velocities in some areas. These areas could not be captured using 14C. Faults were found to play a paramount role on mixing old fluids rich in salts and 4He, although it was not possible to demonstrate the role of faults in changing flow velocities, this requiring a higher density of sampling points. Our study shows that environmental tracers have potential to study flow processes in semi-confined, faulted, multilayered aquifer systems, provided a high density of sampling points is available.
- Published
- 2017
12. Effect of bacteria and virus on transport and retention of graphene oxide nanoparticles in natural limestone sediments
- Author
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Okke Batelaan, Amirhosein Ramazanpour Esfahani, Howard Fallowfield, and John Hutson
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Environmental Engineering ,Health, Toxicology and Mutagenesis ,Microorganism ,0208 environmental biotechnology ,Oxide ,Nanoparticle ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,law.invention ,Divalent ,Calcium Carbonate ,chemistry.chemical_compound ,law ,Groundwater pollution ,Escherichia coli ,Environmental Chemistry ,Groundwater ,0105 earth and related environmental sciences ,chemistry.chemical_classification ,Graphene ,Osmolar Concentration ,Public Health, Environmental and Occupational Health ,Biofilm ,General Medicine ,General Chemistry ,Silicon Dioxide ,Pollution ,020801 environmental engineering ,chemistry ,Chemical engineering ,Ionic strength ,Biofilms ,Nanoparticles ,Graphite ,Water Microbiology ,Porosity - Abstract
This research was conducted to evaluate the effect of co-transport of different-sized microorganisms on graphene oxide nanoparticles (GONPs) transport and retention in saturated pristine and biofilm-conditioned limestone columns. The transport and retention behavior of GONPs was studied in columns in the presence of MS2 -as a nano-sized- and Escherichia coli (E.coli) -as a micro-sized- microorganisms at low and high ionic strength conditions. Results showed no changes in GONPs transport and retention at high ionic strength in the presence of MS2 or E. coli, which was attributed to the effect of high concentration of divalent cation on aggregation of nanoparticles and microorganisms. Furthermore, simultaneous enhanced transport and decreased retention of GONPs in column was observed in the co-presence of microorganisms at low ionic strength. Results revealed that the main mechanism governing increasing GONPs transport in porous media was occupation of reactive surface sites of collectors by microorganisms, which prevented attachment of nanoparticles. The pre-saturation of columns with MS2 and E. coli caused increasing transport of GONPs in the columns, due to the occupation of surface reactive sites. Moreover, conditioning limestone collectors with natural biofilm resulted in the same rates of nanoparticle elution and retention (i.e., in the presence or absence of microorganisms) by straining of GONPs in the inlet end of columns which shows that the biofilm acts as a bio-filter against discharging nanoparticles into the effluents. Finally, from the obtained results, it can be postulated that the presence of microorganisms in a MAR site causes risk of groundwater pollution by toxic nanoparticles.
- Published
- 2019
13. Fresh groundwater lens dynamics of a small bedrock island in the tropics, Northern Australia
- Author
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Joanna Ellis, Karina Meredith, Saskia Noorduijn, Eddie W. Banks, Okke Batelaan, Kevin Cahill, and Vincent E. A. Post
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Hydrology ,Wet season ,geography ,geography.geographical_feature_category ,Hydrogeology ,010504 meteorology & atmospheric sciences ,Lens (hydrology) ,Bedrock ,0207 environmental engineering ,Aquifer ,02 engineering and technology ,Groundwater recharge ,01 natural sciences ,Pore water pressure ,020701 environmental engineering ,Groundwater ,Geology ,0105 earth and related environmental sciences ,Water Science and Technology - Abstract
Fresh groundwater lens dynamics and transition zone geometries on small tropical islands have been investigated in a wide range of geological environments. However, the understanding of multi-aquifer fractured bedrock systems and how they respond to episodic wet season rainfall recharge is still limited. This study used a comprehensive suite of isotopic tracers, hydrogeological and near-surface geophysical methods to characterise the multi-layer aquifer system on Milingimbi, a small bedrock island located in the tropics of the Arafura Sea, Northern Australia. Near-surface geophysics was used to determine the subsurface structure of the aquifer, including the spatial extent and thickness of the fresh groundwater lens and the shape of the transition zone. Pore water chloride profiles, hydrochemistry, and δ18O and δ2H data supported the geophysics results. The lens was found to be 40 m thick on average, with an up to 70 m thick transition zone underneath. Water level time series data over 4 years showed that there was a strong tidal signal observed in the groundwater wells screened in the deeper aquifer and that the aquifer system showed a dynamic response to the wet season rainfall. Time series chloride and δ18O and δ2H rainfall and production bore data suggest that there was a freshening (i.e. lower salinity input) of the lens as a result of recharge during the wet season, which occurs up to 6 months after the event. Groundwater residence time indicators showed that the mean residence time in the lens was at least 25 years and the rate of recharge to the system was up to 200 mm y−1. The comprehensive data set, which is rather unique in its wide range of methods that were applied, resulted in a hydrogeological conceptual model of the multi-layer bedrock aquifer system of the island that also provides insight into the fresh groundwater lens and the transition zone geometry of similar island aquifer systems.
- Published
- 2021
14. Transport and retention of graphene oxide nanoparticles in sandy and carbonaceous aquifer sediments: Effect of physicochemical factors and natural biofilm
- Author
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John Hutson, Howard Fallowfield, Amirhosein Ramazanpour Esfahani, and Okke Batelaan
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Environmental Engineering ,0208 environmental biotechnology ,Oxide ,Ionic bonding ,Nanoparticle ,Aquifer ,02 engineering and technology ,010501 environmental sciences ,Management, Monitoring, Policy and Law ,01 natural sciences ,Metal ,chemistry.chemical_compound ,Sand ,Groundwater ,Waste Management and Disposal ,Quartz ,0105 earth and related environmental sciences ,geography ,geography.geographical_feature_category ,Osmolar Concentration ,General Medicine ,Silicon Dioxide ,020801 environmental engineering ,chemistry ,Chemical engineering ,Ionic strength ,Biofilms ,visual_art ,visual_art.visual_art_medium ,Nanoparticles ,Graphite ,Porous medium ,Porosity - Abstract
There is a paucity of information regarding the interaction between GONPs and natural aquifer sediments. Therefore, batch and column experiments were carried out to determine the transport, retention and attachment behavior of GONPs with the surfaces of native aquifer sediments. The experiments were performed with sediments comprising contrasting mineralogical features (sand grains, quartz and limestone sediments), at different temperatures, ionic strength and compositions. Uniquely, this research also investigated the effect of natural biofilm on the retention behavior of nanoparticles in porous media. The retention rate of GONPs at 22 °C was higher than at 4 °C. Moreover, there was greater retention of GONPs onto the surfaces of collectors at higher ionic strengths and cation valence. The retention profiles (RPs) of GONPs in pristine porous media at low ionic strength were linear, which contrasted with hyper-exponential shape of RPs at high ionic strength. The size-distribution analysis of retained GONPs showed decreasing particle diameter with increasing distance from the column inlet at high ionic strength and equal diameter at low ionic strengths. The GONP retention rate was higher for natural porous media than for sand, due to the presence of metal oxides heterogeneities. The presence of biofilm on porous media increased the retention rate of GONPs when compared to the porous media in the absence of biofilm.
- Published
- 2021
15. Groundwater flow systems theory: research challenges beyond the specified-head top boundary condition
- Author
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Etienne Bresciani, Pascal Goderniaux, Okke Batelaan, Anders Wörman, J.-R. de Dreuzy, Wouter Zijl, Adrian D. Werner, and Tom Gleeson
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Hydrogeology ,010504 meteorology & atmospheric sciences ,Groundwater flow ,0208 environmental biotechnology ,02 engineering and technology ,Groundwater recharge ,01 natural sciences ,Civil engineering ,6. Clean water ,020801 environmental engineering ,Earth and Planetary Sciences (miscellaneous) ,Geotechnical engineering ,Groundwater discharge ,Boundary value problem ,Groundwater model ,Subsurface flow ,Geology ,Groundwater ,0105 earth and related environmental sciences ,Water Science and Technology - Abstract
Groundwater flow systems theory : research challenges beyond the specified-head top boundary condition
- Published
- 2016
16. Combined physical, chemical and biological clogging of managed aquifer recharge and the effect of biofilm on virus transport behavior: A column study
- Author
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Howard Fallowfield, John Hutson, Okke Batelaan, and Amirhosein Ramazanpour Esfahani
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geography ,Suspended solids ,geography.geographical_feature_category ,Process Chemistry and Technology ,Environmental engineering ,Aquifer ,02 engineering and technology ,Groundwater recharge ,010501 environmental sciences ,01 natural sciences ,Clogging ,020401 chemical engineering ,Wastewater ,Hydraulic conductivity ,Environmental science ,0204 chemical engineering ,Safety, Risk, Reliability and Quality ,Waste Management and Disposal ,Effluent ,Groundwater ,0105 earth and related environmental sciences ,Biotechnology - Abstract
In recent years, treated wastewater has been widely used in managed aquifer recharge sites (MAR) for compensation of groundwater shortage in arid and semi-arid areas. However, the presence of suspended solids, microorganisms and pathogenic agents has led to different problems such as aquifer clogging and groundwater contamination. In this study, the effect of treated wastewater on physical, chemical and biological clogging of sand and limestone-packed columns and subsequently transport behavior of solutes and virus was studied. Transport experiments were performed, using the tracer bromide (Br−) and MS2 bacteriophage, in sand and limestone-packed columns irrigated with treated wastewater at different short and long-term periods (2 and 8 weeks). In addition, some physical, chemical and biological features of columns were measured after irrigation with wastewater. Results revealed that injection of treated wastewater for around 2 weeks not only led to the physical and biological clogging, but also caused a significant increase in MS2 retention in the columns. However, increasing limestone column irrigation to 8 weeks increased solutes and MS2 discharge into the column effluents. This is due to increased saturated hydraulic conductivity caused by the formation of heterogeneities in the columns, as a result of calcium dissolution by microbial activity. From the findings of this research, it can be postulated that long-term application of recycled water in limestone aquifers which causes physical heterogeneities and possible preferential flow paths will endanger groundwater resources with pathogenic contaminations.
- Published
- 2020
17. Spatial and temporal recharge estimation of the basement complex in Nigeria, West Africa
- Author
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Khodayar Abdollahi, I. P. Ifabiyi, Jacob Funso Olorunfemi, Eniola Damilola Ashaolu, and Okke Batelaan
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Hydrology ,geography ,geography.geographical_feature_category ,010504 meteorology & atmospheric sciences ,lcsh:QE1-996.5 ,0207 environmental engineering ,Drainage basin ,Aquifer ,02 engineering and technology ,Groundwater recharge ,Structural basin ,01 natural sciences ,lcsh:Geology ,Water balance ,Evapotranspiration ,Earth and Planetary Sciences (miscellaneous) ,Environmental science ,lcsh:GB3-5030 ,020701 environmental engineering ,Surface runoff ,lcsh:Physical geography ,Groundwater ,0105 earth and related environmental sciences ,Water Science and Technology - Abstract
Study region: Osun Drainage Basin, Nigeria. Study focus: Estimating spatial and temporal patterns of recharge is important for sustainable groundwater resources management. This is especially true for data poor regions, such as the Basement Complex in Nigeria, which has shallow aquifers, a proliferation of wells and no efficient groundwater monitoring network. This study evaluates the performance of a spatially distributed monthly water balance model (WetSpass-M) in estimating groundwater recharge. The WetSpass-M model has moderate data demands, which allows for comprehensive assessment of recharge. New hydrological insights for the region: 27 % of the rainfall in Osun drainage basin becomes recharge, while the remaining is lost through evapotranspiration (43 %), surface runoff (21 %) and interception (9 %). September is the month with highest recharge, ranging between 0 and 73 mm in the north and 129 up to 213 mm in the south and northeast of the basin. The study revealed the significance of the applied water balance model in understanding the spatial and temporal status of recharge. Therefore, the spatial and temporal patterns of recharge should be taken into consideration in preparing a sustainable groundwater resources management plan for the Osun drainage basin. Artificial recharge might be adopted to store storm water runoff during wet periods to improve the groundwater supply in dry months. Also, monthly groundwater withdrawals should be regulated in relation to spatial and temporal recharge patterns. Keywords: Groundwater, Recharge, WetSpass-M, Groundwater management, Osun basin
- Published
- 2020
18. Geophysics to enhance agricultural productivity and livelihoods of smallholder farmers through improved groundwater management of the Vientiane Plain, Lao PDR
- Author
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Paul Pavelic, Trine Enemark, Somphasith Douangsavanh, Michael Hatch, Viengthong Xayavong, Phingsaliao Sithiengtham, Eddie W. Banks, Ounakone Xayviliya, and Okke Batelaan
- Subjects
Hydrology (agriculture) ,Electromagnetics ,0208 environmental biotechnology ,Groundwater management ,Environmental science ,02 engineering and technology ,Agricultural productivity ,Water resource management ,Livelihood ,Groundwater ,020801 environmental engineering - Published
- 2018
19. Spatial distribution of groundwater recharge and base flow: Assessment of controlling factors
- Author
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Zainab Zomlot, Okke Batelaan, Marijke Huysmans, Boud Verbeiren, Hydrology and Hydraulic Engineering, Earth System Sciences, and Faculty of Engineering
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Hydrology ,Watershed ,Soil texture ,Base flow ,lcsh:QE1-996.5 ,Principal component analysis ,Hydrograph ,Groundwater recharge ,Spatial distribution ,Recharge ,lcsh:Geology ,Geography ,Earth and Planetary Sciences (miscellaneous) ,Spatial variability ,Flanders ,Relative importance analysis ,lcsh:GB3-5030 ,lcsh:Physical geography ,Groundwater ,Multiple linear regression ,Water Science and Technology - Abstract
Study focus Groundwater is of strategic importance. The accurate estimation of groundwater recharge and assessing the fundamental controlling factors are therefore of utmost importance to protect groundwater systems. We used the spatially-distributed water-balance model WetSpass to estimate long-term average recharge in Flanders. We validated recharge rates with base flow estimates of 67 daily stream flow records using the hydrograph analyses. To this end we performed principal component analysis, multiple linear regression analysis and relative importance analysis to assess the controlling factors of the spatial variation of recharge and base flow with the influencing watershed characteristics. New hydrological insights for the region The average resulting recharge is 235 mm/year and occurs mainly in winter. The overall moderate correlation between base flow estimates and modeled recharge rates indicates that base flow is a reasonable proxy of recharge. Groundwater recharge variation was explained in order of importance by precipitation, soil texture and vegetation cover; while base flow variation was strongly controlled by vegetation cover and groundwater depth. The results of this study highlight the important role of spatial variables in estimation of recharge and base flow. In addition, the prominent role of vegetation makes clear the potential importance of land-use changes on recharge and hence the need to include a proper strategy for land-use change in sustainable management of groundwater resources.
- Published
- 2015
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20. Evapotranspiration of bush encroachments on a temperate mire meadow – A nonlinear function of landscape composition and groundwater flow
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Dorota Mirosław-Świątek, Mateusz Grygoruk, Tomasz Okruszko, Jan Szatyłowicz, Okke Batelaan, and Hydrology and Hydraulic Engineering
- Subjects
Hydrology ,geography ,Evapotranspiration of bush encroachments ,Environmental Engineering ,geography.geographical_feature_category ,Groundwater flow ,composition and groundwater flow ,Wetland ,Land cover ,Vegetation ,Management, Monitoring, Policy and Law ,nonlinear function of landscape ,Water balance ,Evapotranspiration ,Mire ,Environmental science ,Groundwater ,temperate mire meadow ,Nature and Landscape Conservation - Abstract
A B S T R A C T As widely recognized, bush encroachment on mire meadows induces species and habitat biodiversity. However, it is unclear if expansion of either a coherent, continuous forest or randomly distributed groups of trees, so-called tree isles, in formerly open landscapes of mire meadows influences differently the water balance of the system due to changing vegetation structure, landscape, and thus evapotranspiration. In this paper we use a quasi-3D unsaturated–saturated groundwater flow model to reveal the feedback between the actual evapotranspiration and diurnal phreatic groundwater level dynamics. A schematized numerical experiment was setup to elucidate the ecohydrological functioning of mire meadows in the Biebrza Valley (NE Poland), which have been influenced by bush encroachment due to abandonment of mowing. Model calibration and validation was based on field collected data on groundwater dynamics showing the feedback between the evapotranspiration and diurnal groundwater level fluctuations. The model was applied for different landscape compositions of encroachments as well as different stages of shrubby vegetation expansion in a formerly open meadow. It is concluded that for coupled unsaturated– saturated flow models of mires, analysis of diurnal groundwater level fluctuations combined with evapotranspiration quantification is an efficient yet simple method for model calibration and validation. Results of the modelling experiment indicated that the tree-isle-type of bush encroachment entails higher losses of water from the system due to evapotranspiration than coherent forest expansion. For a hypothetical summer drought and an encroachment cover of 50% the total evapotranspiration is shown to be 13% higher for the tree-isle-type encroachment than for expansion of a coherent forest. Consequently, it is concluded that conservation of mires requires continuous control of encroachment not only because of potential loss of biodiversity, but more importantly to limit significant loss of water due to increased evapotranspiration.
- Published
- 2014
21. Model-based classification of CPT data and automated lithostratigraphic mapping for high-resolution characterization of a heterogeneous sedimentary aquifer
- Author
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Marijke Huysmans, Alain Dassargues, Dirk Mallants, Okke Batelaan, Matej Gedeon, Bart Rogiers, Hydrology and Hydraulic Engineering, and Zou, Quan
- Subjects
Lithostratigraphy ,Groundwater flow ,Lithology ,Stratigraphy ,0211 other engineering and technologies ,lcsh:Medicine ,02 engineering and technology ,Soil Chemistry ,Soil/classification ,computer.software_genre ,01 natural sciences ,Infographics ,010104 statistics & probability ,Soil ,Belgium ,lcsh:Science ,Groundwater ,Sedimentary Geology ,Multidisciplinary ,Hydrogeology ,geography.geographical_feature_category ,Agricultural and Biological Sciences(all) ,Applied Mathematics ,Simulation and Modeling ,Soil classification ,Geology ,Environmental monitoring ,Charts ,Chemistry ,Groundwater/standards ,Physical Sciences ,Data mining ,Porosity ,Algorithms ,Research Article ,Computer and Information Sciences ,Materials Science ,Material Properties ,Soil Science ,Aquifer ,Research and Analysis Methods ,Cation Exchange Capacity ,Clustering Algorithms ,Environmental Chemistry ,0101 mathematics ,Cluster analysis ,021101 geological & geomatics engineering ,Petrology ,geography ,Biochemistry, Genetics and Molecular Biology(all) ,Data Visualization ,Ecology and Environmental Sciences ,lcsh:R ,Models, Theoretical ,Cone penetration test ,Earth Sciences ,Sediment ,lcsh:Q ,computer ,Mathematics - Abstract
Cone penetration testing (CPT) is one of the most efficient and versatile methods currently available for geotechnical, lithostratigraphic and hydrogeological site characterization. Currently available methods for soil behaviour type classification (SBT) of CPT data however have severe limitations, often restricting their application to a local scale. For parameterization of regional groundwater flow or geotechnical models, and delineation of regional hydro- or lithostratigraphy, regional SBT classification would be very useful. This paper investigates the use of model-based clustering for SBT classification, and the influence of different clustering approaches on the properties and spatial distribution of the obtained soil classes. We additionally propose a methodology for automated lithostratigraphic mapping of regionally occurring sedimentary units using SBT classification. The methodology is applied to a large CPT dataset, covering a groundwater basin of ~60 km2 with predominantly unconsolidated sandy sediments in northern Belgium. Results show that the model-based approach is superior in detecting the true lithological classes when compared to more frequently applied unsupervised classification approaches or literature classification diagrams. We demonstrate that automated mapping of lithostratigraphic units using advanced SBT classification techniques can provide a large gain in efficiency, compared to more time-consuming manual approaches and yields at least equally accurate results. ispartof: PLoS One vol:12 issue:5 ispartof: location:United States status: published
- Published
- 2017
22. Three-dimensional hydrostratigraphical modelling to support evaluation of recharge and saltwater intrusion in a coastal groundwater system in Vietnam
- Author
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Pham Quy Nhan, Vu Thanh Tam, Tran Thanh Le, and Okke Batelaan
- Subjects
geography ,geography.geographical_feature_category ,Hydrogeology ,Borehole ,Aquifer ,Groundwater recharge ,Geological formation ,Earth and Planetary Sciences (miscellaneous) ,Depression-focused recharge ,Saltwater intrusion ,Petrology ,Geomorphology ,Geology ,Groundwater ,Water Science and Technology - Abstract
Saltwater intrusion is generally related to seawater-level rise or induced intrusion due to excessive groundwater extraction in coastal aquifers. However, the hydrogeological heterogeneity of the subsurface plays an important role in (non-)intrusion as well. Local hydrogeological conditions for recharge and saltwater intrusion are studied in a coastal groundwater system in Vietnam where geological formations exhibit highly heterogeneous lithologies. A three-dimensional (3D) hydrostratigraphical solid model of the study area is constructed by way of a recursive classification procedure. The procedure includes a cluster analysis which uses as parameters geological formation, lithological composition, distribution depth and thickness of each lithologically distinctive drilling interval of 47 boreholes, to distinguish and map well-log intervals of similar lithological properties in different geological formations. A 3D hydrostratigraphical fence diagram is then generated from the constructed solid model and is used as a tool to evaluate recharge paths and saltwater intrusion to the groundwater system. Groundwater level and chemistry, and geophysical direct current (DC) resistivity measurements, are used to support the hydrostratigraphical model. Results of this research contribute to the explanation of why the aquifer system of the study area is almost uninfluenced by saltwater intrusion, which is otherwise relatively common in coastal aquifers of Vietnam.
- Published
- 2014
23. Science-policy interfacing on the issue of groundwater and groundwater-dependent ecosystems in Europe: implications for research and policy
- Author
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Philippe Quevauviller, Bosman Batubara, and Okke Batelaan
- Subjects
Engineering ,Ecology ,business.industry ,media_common.quotation_subject ,Environmental resource management ,Conflict of interest ,Ocean Engineering ,Management, Monitoring, Policy and Law ,Aquatic Science ,Oceanography ,Directive ,media_common.cataloged_instance ,Quality (business) ,Science policy ,European union ,business ,Groundwater ,Environmental quality ,Water Science and Technology ,media_common ,Groundwater-dependent ecosystems - Abstract
A policy-oriented research initiative should be directed to support the development of environmental policy, tackling specific questions and identifying policy gaps. However, that is not always the case. Recent research designed to assist in the revision of the European Union's (EU's) Groundwater Directive (GWD) illustrates different interpretations of research needs by scientists. The EU's GWD made a specific call for research to provide better criteria for ensuring groundwater ecosystem quality and protection (recital 20 of the directive). To date, scientific responses actually focused on a better understanding of groundwater-dependent (aquatic and terrestrial) ecosystems which contributed to a better approach of environmental quality standards (threshold values) but did not fulfil the specific request of the Directive. In term of policy, on-going research is aiming at contributing to the revision of the GWD regarding chemical aspects (and better knowledge of groundwater interactions with associated ecosystems) but is not addressing specific groundwater ecological aspects as required in the Directive's recital. Looking ahead, a stronger interface between policy makers and scientists in the EU is necessary to ensure that research better addresses specific requests of the GWD. WIREs Water 2014, 1:561–571. doi: 10.1002/wat2.1041 For further resources related to this article, please visit the WIREs website. Conflict of interest: The authors have declared no conflicts of interest for this article.
- Published
- 2014
24. High-resolution saturated hydraulic conductivity logging of borehole cores using air permeability measurements
- Author
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Bart Rogiers, Alain Dassargues, Matej Gedeon, Marijke Huysmans, Koen Beerten, Okke Batelaan, P. Winters, and Dirk Mallants
- Subjects
geography ,Hydrogeology ,geography.geographical_feature_category ,Groundwater flow ,Borehole ,Soil science ,Aquifer ,Hydraulic conductivity ,Air permeability specific surface ,Earth and Planetary Sciences (miscellaneous) ,Geomorphology ,Geology ,Groundwater ,Water Science and Technology ,Permeameter - Abstract
Saturated hydraulic conductivity (Ks) is one of the most important parameters determining groundwater flow and contaminant transport in both unsaturated and saturated porous media. The hand-held air permeameter technique was investigated for high-resolution hydraulic conductivity determination on borehole cores using a spatial resolution of ∼0.05 m. The suitability of such air permeameter measurements on friable to poorly indurated sediments was tested to improve the spatial prediction of classical laboratory-based Ks measurements obtained at a much lower spatial resolution (∼2 m). In total, 368 Ks measurements were made on ∼350 m of borehole cores originating from the Campine basin, northern Belgium, while ∼5,230 air permeability measurements were performed on the same cores, resulting in a Ks range of seven orders of magnitude. Cross-validation demonstrated that, using air permeameter data as the secondary variable for laboratory based Ks measurements, the performance increased from R2 = 0.35 for ordinary kriging (laboratory Ks only) to R2 = 0.61 for co-kriging. The separate treatment of horizontal and vertical hydraulic conductivity revealed considerable anisotropy in certain lithostratigraphical units, while others were clearly isotropic at the sample scale. Air permeameter measurements on borehole cores provide a cost-effective way to improve spatial predictions of traditional laboratory based Ks.
- Published
- 2014
25. Is the Hyporheic Zone Relevant beyond the Scientific Community?
- Author
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Margaret Shanafield, Cyrus Rutere, Brian Babak Mojarrad, Okke Batelaan, Claudia Coll, Adrian Löchner Prats, Stefan Krause, Anna Jaeger, Juliane Hollender, Jason Galloway, Malte Posselt, Shai Arnon, Marcus A. Horn, Anders Wörman, Jörg Lewandowski, Liwen Wu, Robert C. Grabowski, Andrea Popp, Joakim Riml, Philipp Wolke, Eddie W. Banks, Anne L. Robertson, Anke Putschew, Jaime Gaona Garcia, Jonas L. Schaper, Hanna Schulz, Tabea Broecker, Mario Schirmer, Muhammad Raza, Birgit Maria Mueller, Adam S. Ward, Jesus D. Gomez-Velez, Chiara Magliozzi, Tanu Singh, Karin Meinikmann, Andrea Betterle, Reinhard Hinkelmann, Anja Höhne, Michael Radke, Ignacio Peralta-Maraver, Jennifer D. Drummond, Skuyler Herzog, and Technische Informationsbibliothek (TIB)
- Subjects
lcsh:Hydraulic engineering ,hyporheic exchange flow ,emerging pollutants ,nutrient turnover ,self-purification capacity ,hyporheic zone ,refuge ,ecosystem services ,surface water–groundwater exchange ,removal of trace organic compounds ,hyporheos ,Geography, Planning and Development ,Surface water-groundwater exchange ,02 engineering and technology ,500 Naturwissenschaften und Mathematik::500 Naturwissenschaften::500 Naturwissenschaften und Mathematik ,010501 environmental sciences ,01 natural sciences ,Biochemistry ,River water ,Ecosystem services ,lcsh:Water supply for domestic and industrial purposes ,020701 environmental engineering ,Groundwater ,Scientific disciplines ,Water Science and Technology ,Groundwater pollution ,Nutrient turnover ,Self-purification ,Ecology ,6. Clean water ,Water quality ,Aquatic organisms ,Habitat ,Groundwater exchanges ,Biogeochemical cycle ,Microplastics ,Hyporheos ,0207 environmental engineering ,Aquatic Science ,Refuge ,Ecosystems ,Trace organic compounds ,ddc:690 ,Emerging pollutants ,Rivers ,lcsh:TC1-978 ,Hyporheic exchange flow ,Organic compounds ,ddc:333 ,Self-purification capacity ,Hyporheic zone ,Ecosystem ,14. Life underwater ,0105 earth and related environmental sciences ,lcsh:TD201-500 ,Stream flow ,Nutrients ,15. Life on land ,Removal of trace organic compounds ,13. Climate action ,Dewey Decimal Classification::600 | Technik::690 | Hausbau, Bauhandwerk ,Environmental science ,690 Hausbau, Bauhandwerk - Abstract
Rivers are important ecosystems under continuous anthropogenic stresses. The hyporheic zone is a ubiquitous, reactive interface between the main channel and its surrounding sediments along the river network. We elaborate on the main physical, biological, and biogeochemical drivers and processes within the hyporheic zone that have been studied by multiple scientific disciplines for almost half a century. These previous efforts have shown that the hyporheic zone is a modulator for most metabolic stream processes and serves as a refuge and habitat for a diverse range of aquatic organisms. It also exerts a major control on river water quality by increasing the contact time with reactive environments, which in turn results in retention and transformation of nutrients, trace organic compounds, fine suspended particles, and microplastics, among others. The paper showcases the critical importance of hyporheic zones, both from a scientific and an applied perspective, and their role in ecosystem services to answer the question of the manuscript title. It identifies major research gaps in our understanding of hyporheic processes. In conclusion, we highlight the potential of hyporheic restoration to efficiently manage and reactivate ecosystem functions and services in river corridors. Horizon 2020 Deutsche Forschungsgemeinschaft
- Published
- 2019
26. The usefulness of outcrop-analogue air-permeameter measurements for analysing aquifer heterogeneity: testing outcrop hydrogeological parameters with independent borehole data
- Author
-
Matej Gedeon, Dirk Mallants, Marijke Huysmans, Alain Dassargues, Koen Beerten, Tom Smeekens, Okke Batelaan, and Bart Rogiers
- Subjects
lcsh:GE1-350 ,geography ,Hydrogeology ,geography.geographical_feature_category ,Groundwater flow ,Outcrop ,lcsh:T ,Borehole ,lcsh:Geography. Anthropology. Recreation ,Soil science ,Aquifer ,lcsh:Technology ,lcsh:TD1-1066 ,Hydraulic conductivity ,lcsh:G ,Spatial variability ,lcsh:Environmental technology. Sanitary engineering ,Geomorphology ,Groundwater ,Geology ,lcsh:Environmental sciences - Abstract
Outcropping sediments can be used as easily accessible analogues for studying subsurface sediments, especially to determine the small-scale spatial variability of hydrogeological parameters. The use of cost-effective in situ measurement techniques potentially makes the study of outcrop sediments even more attractive. We investigate to what degree air-permeameter measurements on outcrops of unconsolidated sediments can be a proxy for aquifer saturated hydraulic conductivity (K) heterogeneity. The Neogene aquifer in northern Belgium, known as a major groundwater resource, is used as the case study. K and grain-size data obtained from different outcropping sediments are compared with K and grain-size data from aquifer sediments obtained either via laboratory analyses on undisturbed borehole cores (K and grain size) or via large-scale pumping tests (K only). This comparison shows a pronounced and systematic difference between outcrop and aquifer sediments. Part of this difference is attributed to grain-size variations and earth surface processes specific to outcrop environments, including root growth, bioturbation, and weathering. Moreover, palaeoenvironmental conditions such as freezing–drying cycles and differential compaction histories will further alter the initial hydrogeological properties of the outcrop sediments. A linear correction is developed for rescaling the outcrop data to the subsurface data. The spatial structure pertaining to outcrops complements that obtained from the borehole cores in several cases. The higher spatial resolution of the outcrop measurements identifies small-scale spatial structures that remain undetected in the lower resolution borehole data. Insights in stratigraphic and K heterogeneity obtained from outcrop sediments improve developing conceptual models of groundwater flow and transport.
- Published
- 2013
27. Using Multiple-Point Geostatistics for Tracer Test Modeling in a Clay-Drape Environment with Spatially Variable Conductivity and Sorption Coefficient
- Author
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Elke Cochet, Mathias Possemiers, Philippe Orban, Alain Dassargues, Benedicta Ronchi, Marijke Huysmans, Okke Batelaan, Katherine Lauriks, and Hydrology and Hydraulic Engineering
- Subjects
geography ,Hydrogeology ,geography.geographical_feature_category ,sorption coefficient ,multiple-point geostatistics ,Soil science ,Sorption ,Aquifer ,Geostatistics ,clay-drape environment ,Mathematics (miscellaneous) ,Hydraulic conductivity ,spatially variably conductivity ,TRACER ,General Earth and Planetary Sciences ,tracer test modeling ,Injection well ,Geomorphology ,Groundwater ,Geology - Abstract
This study investigates the effect of fine-scale clay drapes on tracer transport. A tracer test was performed in a sandbar deposit consisting of cross-bedded sandy units intercalated with many fine-scale clay drapes. The heterogeneous spatial distribution of the clay drapes causes a spatially variable hydraulic conductivity and sorption coefficient. A fluorescent tracer (sodium naphthionate) was injected in two injection wells and ground water was sampled and analyzed from five pumping wells. To determine (1) whether the fine-scale clay drapes have a significant effect on the measured concentrations and (2) whether application of multiple-point geostatistics can improve interpretation of tracer tests in media with complex geological heterogeneity, this tracer test is analyzed with a local three-dimensional ground-water flow and transport model in which fine-scale sedimentary heterogeneity is modeled using multiple-point geostatistics. To reduce memory needs and calculation time for the multiple-point geostatistical simulation step, this study uses the technique of direct multiple-point geostatistical simulation of edge properties. Instead of simulating pixel values, model cell edge properties indicating the presence of irregularly shaped surfaces are simulated using multiple-point geostatistical simulations. Results of a sensitivity analysis show under which conditions clay drapes have a significant effect on the concentration distribution. Calibration of the model against measured concentrations from the tracer tests reduces the uncertainty on the clay-drape parameters. The calibrated model shows which features of the breakthrough curves can be attributed to the geological heterogeneity of the aquifer and which features are caused by other processes. ispartof: Mathematical Geosciences vol:46 issue:5 pages:519-537 status: published
- Published
- 2013
28. The usefulness of outcrop analogue air permeameter measurements for analyzing aquifer heterogeneity: quantifying outcrop hydraulic conductivity and its spatial variability
- Author
-
Bart Rogiers, Tuur Smeekens, Alain Dassargues, Matej Gedeon, Marijke Huysmans, Dirk Mallants, Koen Beerten, and Okke Batelaan
- Subjects
geography ,geography.geographical_feature_category ,Hydrogeology ,Groundwater flow ,Outcrop ,Soil science ,Aquifer ,Hydraulic conductivity ,Spatial variability ,Geomorphology ,Geology ,Groundwater ,Water Science and Technology ,Permeameter - Abstract
Saturated hydraulic conductivity (K) is one of the most important parameters determining groundwater flow and contaminant transport in both unsaturated and saturated porous media. Although several well-established laboratory methods exist for determining K, in situ measurements of this parameter remain very complex and scale dependent. Often, the limited accessibility of subsurface sediments for sampling means an additional impediment to our ability to quantify subsurface K heterogeneity. One potential solution is the use of outcrops as analogues for subsurface sediments. This paper investigates the use of air permeameter measurements on outcrops of unconsolidated sediments to quantify K and its spatial heterogeneity on a broad range of sediment types. The Neogene aquifer in northern Belgium is used as a case study for this purpose. To characterize the variability in K, 511 small-scale air permeability measurements were performed on outcrop sediments representative over five of the aquifer's lithostratigraphic units. From these measurements, outcrop-scale equivalent K tensors were calculated using numerical upscaling techniques. Validation of the air permeameter-based K values by comparison with laboratory constant head K measurements reveals a correlation of 0.93. Overall, the results indicate that hand-held air permeameters are very efficient and accurate tools to characterize saturated K, as well as its small-scale variability and anisotropy on a broad range of unconsolidated sediments. The studied outcrops further provided a qualitative understanding of aquifer hydrostratigraphy and quantitative estimates about K variability at the centimetre-scale to metre-scale. Copyright © 2013 John Wiley & Sons, Ltd.
- Published
- 2013
29. Mapping impervious surface change from remote sensing for hydrological modeling
- Author
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Okke Batelaan, Juliette Dujardin, Imtiaz Bashir, Jef Dams, Reinout Reggers, and Frank Canters
- Subjects
Hydrology ,geography ,geography.geographical_feature_category ,Drainage basin ,Groundwater recharge ,Urban area ,Water balance ,Evapotranspiration ,Impervious surface ,Environmental science ,Groundwater ,Water Science and Technology ,Remote sensing ,Urban runoff - Abstract
This paper describes a method to estimate changes in impervious surface fraction from widely available medium resolution remote sensing data. The potential of the impervious surface fraction data for hydrological modeling is illustrated by a case study for the Kleine Nete catchment, Belgium. Impervious surface fraction data for the Kleine Nete were simulated based on a Landsat TM image acquired in 1986 and a Landsat ETM+ of 2003. The paper assesses the impact of change in impervious surface cover between 1986 and 2003 on the vertical water balance and groundwater system. The results show that impervious surface fractions can be obtained from medium resolution remote sensing data with reasonable accuracy, the mean average error is around 18% and the bias close to zero for both the recent and historical image. Comparing the impervious surface fractions of 1986 and 2003 indicates that most urbanization occurred by densification of existing urban areas. The average impervious fraction of the urban cells increases from 25.4% to 29.2% between 1986 and 2003. Urban runoff increases by 9.5% between 1986 and 2003 due to the increase in impervious surfaces, while the evapotranspiration and recharge in urban areas decrease by 1.5% and 1.6% respectively. For the study area a land-use class based parameterization method underestimates groundwater recharge and head decreases in the most dense urban area and overestimates those in some of the smaller urban centers.
- Published
- 2013
30. Groundwater-surface water interaction in Lake Nasser, Southern Egypt
- Author
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Jan Feyen, Okke Batelaan, M. Bakr, and Mohamed Elsawwaf
- Subjects
Hydrology ,geography ,geography.geographical_feature_category ,Groundwater flow ,Water table ,Groundwater flow equation ,Aquifer ,Groundwater discharge ,Groundwater recharge ,Surface water ,Groundwater ,Geology ,Water Science and Technology - Abstract
A cross-sectional model, based on the two dimensional groundwater flow equation of Edelman, was applied at seven transects distributed over four geological cross sections to estimate groundwater heads and recharge from/or groundwater discharge to Lake Nasser. The lake with a length of 500 km and an average width of 12 km was created over the period 1964–1970, the time for constructing the Aswan High Dam (AHD). The model, constrained by regional-scale groundwater flow and groundwater head data in the vicinity of the lake, was successfully calibrated to timeseries of piezometeric heads collected at the cross sections in the period 1965–2004. Inverse modeling yielded high values for the horizontal hydraulic conductivity in the range of 6.0 to 31.1 m day−1 and storage coefficient between 0.01 and 0.40. The results showed the existence of a strong vertical anisotropy of the aquifer. The calibrated horizontal permeability is systematically higher than the vertical permeability (≈1000:1). The calibrated model was used to explore the recharge from/or groundwater discharge to Lake Nasser at the seven transects for a 40-year period, i.e. from 1965 to 2004. The analysis for the last 20-year period, 1985–2004, revealed that recharge from Lake Nasser reduced by 37% compared to the estimates for the first 20-year period, 1965–1984. In the period 1965–2004, seepage of Lake Nasser to the surrounding was estimated at 1.15 × 109 m3 year−1. This led to a significant rise of the groundwater table. Variance-based sensitivity and uncertainty analysis on the Edelman results were conducted applying quasi-Monte Carlo sequences (Latin Hypercube sampling). The maximum standard deviation of the total uncertainty on the groundwater table was 0.88 m at Toshka (west of the lake). The distance from the lake, followed by the storage coefficient and hydraulic conductivity, were identified as the most sensitive parameters. Copyright © 2012 John Wiley & Sons, Ltd.
- Published
- 2012
31. Impact assessment of climate change on a coastal groundwater system, Central Vietnam
- Author
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Vu Thanh Tam, Ine Beyen, and Okke Batelaan
- Subjects
Hydrology ,Global and Planetary Change ,geography ,geography.geographical_feature_category ,Groundwater flow ,Coastal plain ,0208 environmental biotechnology ,Soil Science ,Climate change ,Geology ,Aquifer ,02 engineering and technology ,Groundwater recharge ,Pollution ,020801 environmental engineering ,Depression-focused recharge ,Environmental Chemistry ,Environmental science ,Groundwater ,Earth-Surface Processes ,Water Science and Technology ,Downscaling - Abstract
Coastal plains in Central Vietnam are characterized by strong seasonal precipitation. As predicted by the A1B gas emission scenario, higher precipitation with more extremes is expected by 2050 for Central Vietnam. To assess impact of these changes on the groundwater resources of the coastal aquifers, a statistical downscaling method with the weather generator LARS-WG coupled with the physically distributed rainfall–runoff model WetSpa and the variable-density groundwater flow model SEAWAT is employed. Results show that contrary to expectation the increase in precipitation by 2050 for the wet months of October and December leads to a sharp decrease in groundwater recharge and groundwater head and consequently a decrease in groundwater resources for the study area. It is concluded that in the assessment of impact of climate change on groundwater resources of coastal sloping plains controlling factors like precipitation intensity in combination with terrain characteristics of the recharge area of aquifers play a major role.
- Published
- 2016
32. Hydrological connectivity of alluvial Andean valleys: a groundwater/surface-water interaction case study in Ecuador
- Author
-
Christian Anibas, Marijke Huysmans, Okke Batelaan, Guido Wyseure, Pablo Guzmán, Hydrology and Hydraulic Engineering, and Earth System Sciences
- Subjects
Hydrology ,geography ,geography.geographical_feature_category ,Hydrogeology ,0208 environmental biotechnology ,Aquifer ,02 engineering and technology ,Groundwater recharge ,Andean catchment ,020801 environmental engineering ,Alluvial plain ,Water resources ,Groundwater/surface-water relations ,Earth and Planetary Sciences (miscellaneous) ,Alluvium ,Surface water ,Geology ,Groundwater ,Water Science and Technology - Abstract
The Andean region is characterized by important intramontane alluvial and glacial valleys; a typical example is the Tarqui alluvial plain, Ecuador. Such valley plains are densely populated and/or very attractive for urban and infrastructural development. Their aquifers offer opportunities for the required water resources. Groundwater/surface-water (GW–SW) interaction generally entails recharge to or discharge from the aquifer, dependent on the hydraulic connection between surface water and groundwater. Since GW–SW interaction in Andean catchments has hardly been addressed, the objectives of this study are to investigate GW–SW interaction in the Tarqui alluvial plain and to understand the role of the morphology of the alluvial valley in the hydrological response and in the hydrological connection between hillslopes and the aquifers in the valley floor. This study is based on extensive field measurements, groundwater-flow modelling and the application of temperature as a groundwater tracer. Results show that the morphological conditions of a valley influence GW–SW interaction. Gaining and losing river sections are observed in narrow and wide alluvial valley sections, respectively. Modelling shows a strong hydrological connectivity between the hillslopes and the alluvial valley; up to 92 % of recharge of the alluvial deposits originates from lateral flow from the hillslopes. The alluvial plain forms a buffer or transition zone for the river as it sustains a gradual flow from the hills to the river. Future land-use planning and development should include concepts discussed in this study, such as hydrological connectivity, in order to better evaluate impact assessments on water resources and aquatic ecosystems. ispartof: Hydrogeology Journal vol:24 issue:1 pages:1-15 status: published
- Published
- 2016
33. Ecohydrology and Its Relation to Integrated Groundwater Management
- Author
-
Okke Batelaan, Masaki Hayashi, and Randall J. Hunt
- Subjects
Resource (biology) ,Scale (chemistry) ,Ecology (disciplines) ,Ecohydrology ,Sustainability ,Water storage ,Environmental science ,Water resource management ,Environmental planning ,Nexus (standard) ,Groundwater - Abstract
In the twentieth century, groundwater characterization focused primarily on easily measured hydraulic metrics of water storage and flows. Twenty-first century concepts of groundwater availability, however, encompass other factors having societal value, such as ecological well-being. Effective ecohydrological science is a nexus of fundamental understanding derived from two scientific disciplines: (1) ecology, where scale, thresholds, feedbacks and tipping points for societal questions form the basis for the ecologic characterization, and (2) hydrology, where the characteristics, magnitude, and timing of water flows are characterized for a defined system of interest. In addition to ecohydrology itself, integrated groundwater management requires input from resource managers to understand which areas of the vast world of ecohydrology are important for decision making. Expectations of acceptable uncertainty, or even what ecohydrological outputs have utility, are often not well articulated within societal decision making frameworks, or within the science community itself. Similarly, “acceptable levels of impact” are difficult to define. Three examples are given to demonstrate the use of ecohydrological considerations for long-term sustainability of groundwater resources and their related ecosystem function. Such examples illustrate the importance of accommodating ecohydrogeological aspects into integrated groundwater management of the twenty-first century, regardless of society, climate, or setting.
- Published
- 2016
34. Groundwater Regulation and Integrated Water Planning
- Author
-
Randall J. Hunt, Philippe Quevauviller, and Okke Batelaan
- Subjects
Sociology of scientific knowledge ,Water Framework Directive ,Process (engineering) ,Scale (social sciences) ,media_common.cataloged_instance ,Business ,European union ,Environmental planning ,Groundwater ,Environmental quality ,Integrated management ,media_common - Abstract
The complex nature of groundwater and the diversity of uses and environmental interactions call for emerging groundwater problems to be addressed through integrated management and planning approaches. Planning requires different levels of integration dealing with: the hydrologic cycle (the physical process) including the temporal dimension; river basins and aquifers (spatial integration); socioeconomic considerations at regional, national and international levels; and scientific knowledge. The great natural variation in groundwater conditions obviously affects planning needs and options as well as perceptions from highly localised to regionally-based approaches. The scale at which planning is done therefore needs to be carefully evaluated against available policy choices and options in each particular setting. A solid planning approach is based on River Basin Management Planning (RBMP), which covers: (1) objectives that management planning are designed to address; (2) the way various types of measures fit into the overall management planning; and (3) the criteria against which the success or failure of specific strategies or interventions can be evaluated (e.g. compliance with environmental quality standards). A management planning framework is to be conceived as a “living” or iterated document that can be updated, refined and if necessary changed as information and experience are gained. This chapter discusses these aspects, providing an insight into European Union (EU), United States and Australia groundwater planning practices.
- Published
- 2016
35. Climate change impact on river flows and catchment hydrology: a comparison of two spatially distributed models
- Author
-
Mohsen Tavakoli, Florimond De Smedt, Patrick Willems, Okke Batelaan, Victor Ntegeka, and Thomas Vansteenkiste
- Subjects
Catchment hydrology ,Hydrology ,geography ,geography.geographical_feature_category ,Groundwater flow ,Flow (psychology) ,Drainage basin ,Climate change ,MIKE SHE ,Surface water ,Groundwater ,Water Science and Technology - Abstract
Hydrological models have been widely used to assess changes in stream discharges by climate change; however, concern might arise on the accurateness of the model predictions under the changed conditions particularly during low flow periods. In this study, two spatially distributed hydrological models MIKE SHE and WetSpa, each representing a different model complexity in terms of process description, data needs, parameter space, degree of calibration, were compared in their estimation of the climate change impact on the flow regimes in a medium-sized catchment in Belgium. The fully integrated, physically based MIKE SHE model, comprising a three-dimensional groundwater flow and river model, was applied to better understand the groundwater flow and groundwater–river interactions under changed climate conditions. Both models were able to capture the flow dynamics very well with high efficiencies and simulated the flow extremes very accurately. The groundwater heads in MIKE SHE and their seasonal variation had a high model performance. The two models simulated similar changes to future flows because of climatic changes. Peak flows were expected to increase or decrease depending, taking the large uncertainty in future climate trends into account. The model structural uncertainties on these high flow predictions were rather limited. Low flows were expected to reduce because of drier conditions by future climate change, indicating elevated low flow risks for Belgium. However, the projected low flow changes differed significantly over the models and even exceeded the uncertainty by the expected climate trends. Smaller impact was predicted by considering the groundwater physics and river interaction in the MIKE SHE model. These changes to the surface water regimes were verified by the changes in groundwater heads. Future groundwater conditions also point towards drier conditions with a small decrease in heads for future summer and autumn periods. Projected variations in winter heads depend on the climate scenario. Copyright © 2012 John Wiley & Sons, Ltd.
- Published
- 2012
36. Transient or steady-state? Using vertical temperature profiles to quantify groundwater-surface water exchange
- Author
-
Ronny Verhoeven, Christian Anibas, Okke Batelaan, Patrick Meire, Jan H. Fleckenstein, Nina Volze, Kerst Buis, and Hydrology and Hydraulic Engineering
- Subjects
Hydrology ,geography ,geography.geographical_feature_category ,Steady state ,Diurnal temperature variation ,heat transport modelling ,Aquifer ,Atmospheric sciences ,groundwater–surface water interaction ,Physics::Geophysics ,hyporheic zone ,Flux (metallurgy) ,TRACER ,Hyporheic zone ,Environmental science ,Biology ,Surface water ,Physics::Atmospheric and Oceanic Physics ,Groundwater ,Water Science and Technology - Abstract
Heat is recognized as a natural tracer to identify the exchange of water between the groundwater and surface water compartment. One-dimensional (1D) heat transport models have the ability to obtain quantitative estimates of vertical fluxes through the sediment matrix. Input to these models can come from temperatures observed in the surface water and in the bed material of rivers and lakes. The upper thermal boundary condition at the groundwater-surface water interface is affected by seasonal and diurnal temperature variations. We hypothesize that effects of these transient influences are negligible at certain times of the year, such that the vertical temperature distribution can be approximated to be at steady state. Temperature time series observed over a year in the surface water and at several depths below a river in Belgium and in sediments of an acid mine lake in Eastern Germany were simulated with a heat balance model implemented in FEMME and the water and energy model VS2DH to obtain seepage fluxes. Temperature variations throughout the year at all depths could be adequately reproduced with the transient models. Vertical temperature profiles at several measuring times during the year were also fitted with an analytical, steady-state solution for 1D heat transport and the obtained fluxes compared to the results from transient simulations. Fluxes obtained from the much simpler steady-state solution were compared well with the flux rates from transient simulations for moments between mid and late summer, as well as during the winter. During transitional seasons (fall and spring), the fluxes from the steady-state solution deviated significantly from the transient estimates with a tendency to underestimate at the beginning and to overestimate towards the end of those seasons. We conclude that fitting a simple analytical solution for 1D vertical heat transport to temperature data observed at particular well-selected times of the year can provide an inexpensive, simple method to obtain accurate point estimates of groundwater-surface water exchange in rivers and lakes.
- Published
- 2009
37. Benefit and Implementation of Groundwater Protection Zoning in South Africa
- Author
-
Luc Brendonck, J.m. Nel, Yongxin Xu, and Okke Batelaan
- Subjects
Land use ,business.industry ,Environmental engineering ,Water supply ,Land-use planning ,Water resources ,Groundwater pollution ,Zoning ,business ,Environmental planning ,health care economics and organizations ,Groundwater ,Water Science and Technology ,Civil and Structural Engineering ,Waste disposal - Abstract
Groundwater studies in several African countries show that the contamination of water-supply aquifers is mainly due to improper placement of land-based activities such as agriculture, industries, waste disposal. In South Africa, groundwater pollution is also of increasing concern due to fast population growth and accompanying development. Groundwater protection zoning is a supplemental methodology for groundwater management that incorporates land use planning. The land is managed to minimize the potential of groundwater contamination by human activities that occur on or below the land surface. The various benefits associated with implementation of protection zoning are discussed for stakeholders such as communities, water supply companies, ecosystems and policy makers. A South African case study is presented comparing the cost of protection with the cost incurred due to the treatment of sick and dying people due to contaminated drinking water. These benefits must be communicated to the stakeholders to start the implementation at all management levels. Implementation steps of groundwater protection zones are discussed and can be tested even with low budgets and little data available. Monitoring and reassessment of protection zones are important to test the effectiveness and prove to decision makers that the money was well spent. The legal framework for implementation of groundwater protection zoning in a South African context is described, where the water law makes provision for tools like differentiated protection, licensing and recovery of cost. Challenges regarding implementation of groundwater protection are discussed with some action steps on how to move forward.
- Published
- 2009
38. GIS-based recharge estimation by coupling surface–subsurface water balances
- Author
-
Okke Batelaan and F. De Smedt
- Subjects
Hydrology ,Water balance ,Baseflow ,Water table ,Evapotranspiration ,Depression-focused recharge ,Environmental science ,Groundwater recharge ,Groundwater model ,Groundwater ,Water Science and Technology - Abstract
A spatially distributed water balance model is developed to simulate long-term average recharge depending on land cover, soil texture, topography and hydrometeorological parameters. The model simulates recharge iteratively connected to a groundwater model, such that the recharge estimate is also influenced by the groundwater depth and vice versa. Parameter estimation for the model is performed on the basis of literature values of water balance fluxes from mainly Belgium and The Netherlands. By graphical and non-linear baseflow separation for 17 catchments it is shown that recharge spatially varies considerably. The water balance model coupled to a regional groundwater model is applied and successfully tested on the 17 catchments. The application shows that the resulting recharge has a spatial complex pattern, depending to a large extend on the soil texture and land cover. Moreover, shallow groundwater levels in valleys cause negative recharge conditions as a result of evapotranspiration by abundant phreatophytic vegetation. GIS analysis shows how recharge strongly varies for different combinations of land cover and soil texture classes. The performed analysis provides a better insight into the sustenance and management of groundwater resources.
- Published
- 2007
39. Use of geophysics to support water security and increase community awareness on Milingimbi Island, northern Australia
- Author
-
Vincent E. A. Post, Peter G. Cook, Okke Batelaan, Eddie W. Banks, Lauren Houthuysen, Joanna Ellis, Kevin Cahill, and William Dean
- Subjects
Borehole geophysics ,Water security ,Northern australia ,Earth science ,Climatology ,Community awareness ,Groundwater ,Geology - Published
- 2015
40. Combining flux estimation techniques to improve characterization of groundwater-surface water interaction in the Zenne river, Belgium
- Author
-
Pierre Jamin, Juliette Dujardin, Winnie Dejonghe, Christian Anibas, Kelly Hamonts, Jan Bronders, Serge Brouyère, Okke Batelaan, Hydrology and Hydraulic Engineering, and Earth System Sciences
- Subjects
Hydrology ,Hydraulic head ,Hydrogeology ,Groundwater flow ,Earth and Planetary Sciences (miscellaneous) ,Environmental science ,Groundwater discharge ,Fluid transport ,Groundwater model ,Surface water ,Groundwater ,Water Science and Technology - Abstract
The management of urban rivers which drain contaminated groundwater is suffering from high uncertainties regarding reliable quantification of groundwater fluxes. Independent techniques are combined for estimating these fluxes towards the Zenne River, Belgium. Measured hydraulic gradients, temperature gradients in conjunction with a 1D-heat and fluid transport model, direct flux measurement with the finite volume point dilution method (FVPDM), and a numerical groundwater flow model are applied, to estimate vertical and horizontal groundwater fluxes and groundwater–surface-water interaction. Hydraulic gradient analysis, the temperature-based method, and the groundwater flow model yielded average vertical fluxes of –61, –45 and –40 mm/d, respectively. The negative sign indicates upward flow to the river. Changes in exchange fluxes are sensitive to precipitation but the river remained gaining during the examined period. The FVPDM, compared to the groundwater flow model, results in two very high estimates of the horizontal Darcy fluxes (2,600 and 500 mm/d), depending on the depth of application. The obtained results allow an evaluation of the temporal and spatial variability of estimated fluxes, thereby helping to curtail possible consequences of pollution of the Zenne River as final receptor, and contribute to the setup of a suitable remediation plan for the contaminated study site.
- Published
- 2015
41. Test of a distributed modelling approach to predict flood flows in the karst Suoimuoi catchment in Vietnam
- Author
-
Y. B. Liu, F. De Smedt, V.t. Tam, Okke Batelaan, and NT Huong
- Subjects
Hydrology ,geography ,Geographic information system ,geography.geographical_feature_category ,Flood myth ,business.industry ,General Engineering ,Drainage basin ,Storm ,Aquifer ,Karst ,Earth and Planetary Sciences (miscellaneous) ,General Earth and Planetary Sciences ,Environmental Chemistry ,Environmental science ,business ,Surface runoff ,Groundwater ,General Environmental Science ,Water Science and Technology - Abstract
The major obstacles for modelling flood processes in karst areas are a lack of understanding and model representations of the distinctive features and processes associated with runoff generation and often a paucity of field data. In this study, a distributed flood-modelling approach, WetSpa, is modified and applied to simulate the hydrological features and processes in the karst Suoimuoi catchment in northwest Vietnam. With input of topography, land use and soil types in a GIS format, the model is calibrated based on 15 months of hourly meteorological and hydrological data, and is used to simulate both fast surface and conduit flows, and groundwater discharges from karst and non-karst aquifers. Considerable variability in the simulation accuracy is found among storm events and within the catchment. The simulation results show that the model is able to represent reasonably well the stormflows generated by rainfall events in the study catchment.
- Published
- 2005
42. SEEPAGE, a New MODFLOW DRAIN Package
- Author
-
Okke Batelaan, F. De Smedt, Hydrology and Hydraulic Engineering, and Vrije Universiteit Brussel
- Subjects
Geological Phenomena ,Water table ,MODFLOW ,Isotropy ,Boundary (topology) ,Geology ,Models, Theoretical ,Soil ,Water balance ,Water Supply ,Water Movements ,Head (vessel) ,Geotechnical engineering ,Computers in Earth Sciences ,Drainage ,Ecosystem ,Groundwater ,Forecasting ,Water Science and Technology - Abstract
The prediction of the location of ground water discharge areas is a key aspect for the protection and (re)development of ground water-dependent wetlands. Ground water discharge areas can be simulated with MODFLOW using the DRAIN package by setting the drain level equal to the topography, while the conductance is mostly set to an arbitrary high value. However, conceptual and practical problems arise in the calculation of the ground water discharge by the DRAIN package as calculated water tables above the land surface, difficult parameterization of the conductance, and large water balance errors. To overcome these problems, a new SEEPAGE package for MODFLOW is proposed. The basic idea of this package is an adaptable constant head cell. It has a variable head, unless the ground water rises above the seepage level, in which case it has a constant head cell. The estimation of the ground water discharge location along a homogeneous, isotropic, linear sloping profile is used to verify the model and to compare it to the DRAIN solution. In an application to three basins in Belgium, it is shown that the SEEPAGE package can be used in combination with the DRAIN package in situations where an upper boundary for a free water table and additional resistance for drainage is required. It is clearly demonstrated that the identification and delineation of regional ground water discharge areas is more accurate using the SEEPAGE package.
- Published
- 2004
43. Intercomparison of hydrological model structures and calibration approaches in climate scenario impact projections
- Author
-
Mohsen Tavakoli, Thomas Vansteenkiste, Victor Ntegeka, Patrick Willems, Florimond De Smedt, Fernando Lobo Pereira, Okke Batelaan, and Hydrology and Hydraulic Engineering
- Subjects
Intercomparison of hydrological model structures ,Hydrology (agriculture) ,Climatology ,calibration approaches in climate scenario impact ,Flow (psychology) ,Environmental science ,Climate change ,Context (language use) ,MIKE SHE ,MIKE 11 ,Surface runoff ,Groundwater ,Water Science and Technology - Abstract
Summary The objective of this paper is to investigate the effects of hydrological model structure and calibration on climate change impact results in hydrology. The uncertainty in the hydrological impact results is assessed by the relative change in runoff volumes and peak and low flow extremes from historical and future climate conditions. The effect of the hydrological model structure is examined through the use of five hydrological models with different spatial resolutions and process descriptions. These were applied to a medium sized catchment in Belgium. The models vary from the lumped conceptual NAM, PDM and VHM models over the intermediate detailed and distributed WetSpa model to the fully distributed MIKE SHE model. The latter model accounts for the 3D groundwater processes and interacts bi-directionally with a full hydrodynamic MIKE 11 river model. After careful and manual calibration of these models, accounting for the accuracy of the peak and low flow extremes and runoff subflows, and the changes in these extremes for changing rainfall conditions, the five models respond in a similar way to the climate scenarios over Belgium. Future projections on peak flows are highly uncertain with expected increases as well as decreases depending on the climate scenario. The projections on future low flows are more uniform; low flows decrease (up to 60%) for all models and for all climate scenarios. However, the uncertainties in the impact projections are high, mainly in the dry season. With respect to the model structural uncertainty, the PDM model simulates significantly higher runoff peak flows under future wet scenarios, which is explained by its specific model structure. For the low flow extremes, the MIKE SHE model projects significantly lower low flows in dry scenario conditions in comparison to the other models, probably due to its large difference in process descriptions for the groundwater component, the groundwater–river interactions. The effect of the model calibration was tested by comparing the manual calibration approach with automatic calibrations of the VHM model based on different objective functions. The calibration approach did not significantly alter the model results for peak flow, but the low flow projections were again highly influenced. Model choice as well as calibration strategy hence have a critical impact on low flows, more than on peak flows. These results highlight the high uncertainty in low flow modelling, especially in a climate change context.
- Published
- 2014
44. Simple hydraulic conductivity estimation by the Kalman filtered double constraint method
- Author
-
Mustafa El-Rawy, Okke Batelaan, and Wouter Zijl
- Subjects
Mathematical optimization ,Groundwater flow ,MODFLOW ,Boundary (topology) ,Mechanics ,Kalman filter ,Models, Theoretical ,Grid ,Hydraulic conductivity ,Belgium ,Calibration ,Water Movements ,Computers in Earth Sciences ,Hydrology ,Groundwater ,Water Science and Technology ,Mathematics ,Block (data storage) - Abstract
This paper presents the Kalman Filtered Double Constraint Method (DCM-KF) as a technique to estimate the hydraulic conductivities in the grid blocks of a groundwater flow model. The DCM is based on two forward runs with the same initial grid block conductivities, but with alternating flux-head conditions specified on parts of the boundary and the wells. These two runs are defined as: (1) the flux run, with specified fluxes (recharge and well abstractions), and (2) the head run, with specified heads (measured in piezometers). Conductivities are then estimated as the initial conductivities multiplied by the fluxes obtained from the flux run and divided by the fluxes obtained from the head run. The DCM is easy to implement in combination with existing models (e.g., MODFLOW). Sufficiently accurate conductivities are obtained after a few iterations. Because of errors in the specified head-flux couples, repeated estimation under varying hydrological conditions results in different conductivities. A time-independent estimate of the conductivities and their inaccuracy can be obtained by a simple linear KF with modest computational requirements. For the Kleine Nete catchment, Belgium, the DCM-KF yields sufficiently accurate calibrated conductivities. The method also results in distinguishing regions where the head-flux observations influence the calibration from areas where it is not able to influence the hydraulic conductivity.
- Published
- 2013
45. A distributed model for water and energy transfer between soil, plants and atmosphere (WetSpa)
- Author
-
Zhong-Min Wang, F. De Smedt, and Okke Batelaan
- Subjects
Hydrology ,Infiltration (hydrology) ,Groundwater flow ,Vadose zone ,General Earth and Planetary Sciences ,Environmental science ,Groundwater recharge ,Groundwater model ,Subsurface flow ,Surface runoff ,Groundwater - Abstract
A physically based and distributed model has been developed for predicting the Water and Energy Transfer between Soil, Plants and Atmosphere (WetSpa) at the regional or basin scale. The model conceptualizes a basin hydrological system being composed of atmosphere, canopy, root zone, transmission zone and saturation zone layers. The basin is divided into a number of grid cells, for which the water and energy balance are maintained. Water movement in the soil is simplified as one-dimensional vertical flow, including surface infiltration, percolation and capillary rise in the unsaturated zone and recharge to groundwater. The model simulates the Hortonian overland flow and the variable-source-area concepts of runoff generation. In order to have a more realistic representation of the interaction between surface runoff and groundwater, a groundwater flow model is integrated.
- Published
- 1996
46. Spatio-temporal impact of climate change on the groundwater system
- Author
-
Jef Dams, Patrick Willems, Victor Ntegeka, Okke Batelaan, T. Van Daele, Elga Salvadore, and Hydrology and Hydraulic Engineering
- Subjects
Hydrological cycle ,spatiotemporal impact ,Climate ,Climate change ,lcsh:Technology ,lcsh:TD1-1066 ,Climate policy (inc. Biomass energy with carbon capture and storage) ,Belgium ,Depression-focused recharge ,Groundwater discharge ,lcsh:Environmental technology. Sanitary engineering ,lcsh:Environmental sciences ,lcsh:GE1-350 ,Hydrology ,B003-ecology ,Baseflow ,statistics and modelling ,lcsh:T ,Global warming ,lcsh:Geography. Anthropology. Recreation ,Nete ,Groundwater recharge ,Water resources ,climate change ,lcsh:G ,Environmental science ,Water catchment ,Groundwater modelling ,Groundwater - Abstract
Given the importance of groundwater for food production and drinking water supply, but also for the survival of groundwater dependent terrestrial ecosystems (GWDTEs) it is essential to assess the impact of climate change on this freshwater resource. In this paper we study with high temporal and spatial resolution the impact of 28 climate change scenarios on the groundwater system of a lowland catchment in Belgium. Our results show for the scenario period 2070–2101 compared with the reference period 1960–1991, a change in annual groundwater recharge between −20% and +7%. On average annual groundwater recharge decreases 7%. In most scenarios the recharge increases during winter but decreases during summer. The altered recharge patterns cause the groundwater level to decrease significantly from September to January. On average the groundwater level decreases about 7 cm with a standard deviation between the scenarios of 5 cm. Groundwater levels in interfluves and upstream areas are more sensitive to climate change than groundwater levels in the river valley. Groundwater discharge to GWDTEs is expected to decrease during late summer and autumn as much as 10%, though the discharge remains at reference-period level during winter and early spring. As GWDTEs are strongly influenced by temporal dynamics of the groundwater system, close monitoring of groundwater and implementation of adaptive management measures are required to prevent ecological loss. ispartof: Hydrology and Earth System Sciences vol:16 issue:5 pages:1517-1531 status: published
- Published
- 2012
47. Groundwater Modelling and Hydrological System Analysis of Wetlands in the Middle Biebrza Basin
- Author
-
Dorota Mirosław-Świątek, Okke Batelaan, Jarosław Chormański, Tomasz Okruszko, Marek Rycharski, and Mateusz Grygoruk
- Subjects
Hydrology ,Hydrogeology ,Groundwater flow ,Environmental science ,Groundwater discharge ,Groundwater recharge ,Drainage ,Structural basin ,Groundwater model ,Groundwater - Abstract
In the presented approach, a three dimensional finite-difference steady-state groundwater model was applied to analyze the groundwater flow system of the Middle Biebrza Basin. Study contains analysis of hydrogeological and morphological outline of the area, as well as the description of developed groundwater model including conceptual model description, model calibration and sensitivity analysis of parameters. Analysis of volumetric water budget of the model within assumed boundary conditions indicated that groundwater resources of the analyzed part of the Middle Biebrza Basin in approximately 80% come from lateral inflow from the adjacent plateaus. Analysis of spatial distribution of groundwater discharge indicated that the most intensive groundwater inflow to the top peat layer is concentrated within the “Czerwone Bagno”, where the peatlands are not degraded and wetland habitats develop naturally, not being directly impacted by drainage ditches and canals.
- Published
- 2011
48. Evaluating the impact of river restoration on the local groundwater and ecological system: a case study in NE Flanders
- Author
-
Rogiers, B., Lermytte, J., Bie, E., Okke Batelaan, and Hydrology and Hydraulic Engineering
- Subjects
Conceptual modelling ,Belgium ,Water ,Groundwater ,River restoration - Abstract
River restoration changes the interaction between groundwater and surface water. Therefore, it is expected to have an impact on ecosystems at the interface between groundwater and surface water. Quantifying and generalizing the level of change of this interaction for different hydrogeological environments is scientifically and practically challenging. In this paper we investigated the impact of different restoration measures and the effect on the interaction of the temporal resolution of the groundwater modeling methodology. The interaction is analysed in the water bodies and wetlands in the valley of the Zwarte Beek, one of the most valuable nature reserves of Flanders. In the past, several changes have been made to the river and drainage system. These adaptations are now considered to be bottlenecks in maintaining a good ecological and hydrological status of its water dependent biotopes. Hence, in the context of the EU Water Framework Directive, it is necessary to (at least partly) restore the initial natural situation. The measures proposed include the reinstatement of old meanders and the removal of a weir. By removing the weir, fish migration is again possible. Reconnecting old meanders increases the habitat diversity. We used transient groundwater modeling to evaluate the impact on the groundwater system of the wetlands. Results indicate that a peat layer, present in most of the wetland, minimizes the effects of the restoration on the groundwater table. The largest changes are confined to the areas near the old meanders and the weir. Steady-state situations do not allow a calculation of average lowest and highest groundwater levels, which are essential for simulating ecological site conditions. Hence, transient simulations with 14 days time steps are required to detect a considerably greater range of groundwater fluctuation than indicated by the seasonal simulation. It is shown that the river restoration project thus resulted in an improvement of the structure of the watercourse rather than the rewetting of the valley. We concluded also that high resolution transient groundwater modeling is an essential step towards river restoration and ecohydrological predictions.
- Published
- 2011
49. On the value of conditioning data to reduce conceptual model uncertainty in groundwater modeling
- Author
-
Luc Feyen, Alain Dassargues, Rodrigo Rojas, and Okke Batelaan
- Subjects
Hydrogeology ,Offset (computer science) ,Data collection ,Groundwater flow ,Computer science ,Econometrics ,GLUE ,Groundwater model ,Bayesian inference ,Groundwater ,Water Science and Technology - Abstract
[1] Recent applications of multimodel methods have demonstrated their potential in quantifying conceptual model uncertainty in groundwater modeling applications. To date, however, little is known about the value of conditioning to constrain the ensemble of conceptualizations, to differentiate among retained alternative conceptualizations, and to reduce conceptual model uncertainty. We address these questions by conditioning multimodel simulations on measurements of hydraulic conductivity and observations of system-state variables and evaluating the effects on (1) the posterior multimodel statistics and (2) the contribution of conceptual model uncertainty to the predictive uncertainty. Multimodel aggregation and conditioning is performed by combining the Generalized Likelihood Uncertainty Estimation (GLUE) method and Bayesian Model Averaging (BMA). As an illustrative example we employ a 3-dimensional hypothetical system under steady state conditions, for which uncertainty about the conceptualization is expressed by an ensemble (M) of seven models with varying complexity. Results show that conditioning on heads allowed for the exclusion of the two simplest models, but that their information content is limited to further differentiate among the retained conceptualizations. Conditioning on increasing numbers of conductivity measurements allowed for a further refinement of the ensemble M and resulted in an increased precision and accuracy of the multimodel predictions. For some groundwater flow components not included as conditioning data, however, the gain in accuracy and precision was partially offset by strongly deviating predictions of a single conceptualization. Identifying the conceptualization producing the most deviating predictions may guide data collection campaigns aimed at acquiring data to further eliminate such conceptualizations. Including groundwater flow and river discharge observations further allowed for a better differentiation among alternative conceptualizations and drastic reductions of the predictive variances. Results strongly advocate the use of observations less commonly available than groundwater heads to reduce conceptual model uncertainty in groundwater modeling.
- Published
- 2010
50. Improving surface-subsurface water budgeting using high resolution satellite imagery applied on a brownfield
- Author
-
Jan Bronders, Okke Batelaan, Simon Boel, Juliette Dujardin, Christian Anibas, Frank Canters, Hydrology and Hydraulic Engineering, Geography, and Cartography and Geographical Information Science
- Subjects
Conservation of Natural Resources ,Environmental Engineering ,brownfields ,urban recharge modeling ,Fresh Water ,Land cover ,satellite imagery ,water budgeting ,remote sensing ,Brownfield ,Water Cycle ,Water Supply ,Groundwater pollution ,Hydrocarbons, Chlorinated ,Environmental Chemistry ,Soil Pollutants ,Satellite imagery ,Spacecraft ,Subsurface flow ,Waste Management and Disposal ,Hydrology ,object-oriented classification ,MODFLOW ,Groundwater recharge ,Pollution ,brownfield ,Models, Chemical ,Remote Sensing Technology ,Geographic Information Systems ,Environmental science ,Groundwater ,Water Pollutants, Chemical ,Environmental Monitoring - Abstract
The estimation of surface–subsurface water interactions is complex and highly variable in space and time. It is even more complex when it has to be estimated in urban areas, because of the complex patterns of the land-cover in these areas. In this research a modeling approach with integrated remote sensing analysis has been developed for estimating water fluxes in urban environments. The methodology was developed with the aim to simulate fluxes of contaminants from polluted sites. Groundwater pollution in urban environments is linked to patterns of land use and hence it is essential to characterize the land cover in a detail. An object-oriented classification approach applied on high-resolution satellite data has been adopted. To assign the image objects to one of the land-cover classes a multiple layer perceptron approach was adopted (Kappa of 0.86). Groundwater recharge has been simulated using the spatially distributed WetSpass model and the subsurface water flow using MODFLOW in order to identify and budget water fluxes. The developed methodology is applied to a brownfield case site in Vilvoorde, Brussels (Belgium). The obtained land use map has a strong impact on the groundwater recharge, resulting in a high spatial variability. Simulated groundwater fluxes from brownfield to the receiving River Zenne were independently verified by measurements and simulation of groundwater-surface water interaction based on thermal gradients in the river bed. It is concluded that in order to better quantify total fluxes of contaminants from brownfields in the groundwater, remote sensing imagery can be operationally integrated in a modeling procedure.
- Published
- 2010
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