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Copyright of Journal of Resources & Ecology is the property of Journal of Resources & Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A new landfill cover system, biochar-methanotrophs-clay (BMC) cover is recommended for reducing methane emissions at landfills. It also contributes to decreasing soil permeability and improving soil water retention in a long time, due to highly porous structure of biochar and the growth metabolism of methanotrophs. To determine the effects of biochar content, oxidation aging times and methane-filled days on hydraulic properties, a total of 60 groups of experiments were conducted. The saturated hydraulic conductivity (ksat) was obtained by flexible wall permeameter with controllable hydraulic head pressure. The results showed that the ksat of BMC increased with increasing biochar content and oxidation aging times, while decreased with adding methane-filled days. The soil-water characteristic curves (SWCCs) were obtained with soil suction measured by the filter paper method. The results indicated the water retention capacity of MBC reduced with increasing oxidation aging times but increased with adding methane-filled days. Detected by mercury intrusion porosimetry (MIP), fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM), the differences displayed the changes of pore structures and extracellular polymeric substances (EPS). The oxidation aging of biochar increased the volume of pores, resulting in the increased ksat and the decreased water retention capacity. However, the growing of methanotrophs decreased the volume of pores, resulting in the ksat decreased and the water retention capacity increased due to EPS. No matter how many times the oxidation aging process was experienced, the BMC with longer methane-filled days exhibited relatively lower ksat and better water retention capacity. This implied a more stable barrier capacity to reduce water infiltration in the long term. By combing a series of macro and micro experiments, this paper provides theoretical guidance for the application of biocharmethanotroph- clay mixture to landfill covers. [ABSTRACT FROM AUTHOR]

This study presents the first report of per‐ and polyfluoroalkyl substances (PFAS) in water samples collected in the Arroyo Colorado (n = 15), irrigation canals (n = 6), stormwater and wastewater retention ponds (n = 7), as well as drinking waters (n = 2) across the Arroyo Colorado watershed. Of the 30 PFAS monitored in this study, 14 were detected in the samples in various combinations. Short‐chain PFAS (less than 8 carbon atoms) were observed in most samples. Water collected from the Arroyo Colorado showed significant spatial variabilities, with high total PFAS concentrations observed near possible point sources ‐ a municipal airport and wastewater treatment facilities. PFAS concentrations were generally higher in water samples collected in stormwater and wastewater retention ponds than in the Arroyo Colorado and irrigation canals. PFAS in stormwater retention ponds likely came from roadway runoff. Short‐chain PFAS were observed in the two municipal water samples, but they were below the current U.S. EPA regulation limits or are not currently regulated. This study provides useful information for water quality in this region and provides insights into PFAS occurrence in a rapidly urbanizing area. [ABSTRACT FROM AUTHOR]

The present paper proposes to analyse the consistency of several interpolation methods for generating a grid structure, which will be used for digital terrain modelling in the case of water retention basins (polders). The aim is to use a single dataset, from which a number of measured points will be eliminated, after which several interpolation methods will be applied to the remaining dataset in order to analyze which method yields the nearest correct (measured) value. The research focuses on comparing the reliability, consistency and sheer data accuracy (in comparison with pre-determined control points) of both the resulted grids and the noise filtered ones, to assess the performance of each method. [ABSTRACT FROM AUTHOR]

Urbanization drives multiple environmental changes that influence critical ecosystem processes. Factors such as salinization by deicing road salts, reduced water clarity (and greater light attenuation) from eutrophication and sediment loading, and warming constrain not only the biodiversity of ponds, but also their physical mixing (with consequences for oxygen availability and the provision of ecosystem services). Leveraging an extensive urban gradient in the Greater Toronto Area, we collected summertime depth profiles from 50 stormwater retention ponds to investigate their vertical stratification. We found that water columns were generally stratified but contrary to expectations, we found relatively minor roles of basin area and depth. Instead, we discovered an overwhelming effect of salinity along with significant impacts of temperature and water clarity on water density gradients. Findings extend our fundamental understanding of mixing regimes in small, shallow waterbodies and indicate increasing risks to pond functioning in a warmer and saltier future. [ABSTRACT FROM AUTHOR]

As interest has increased in green infrastructure and nature-based solutions, traditional approaches to managing landscapes have emerged as providing useful models for sustainable water and land management. From local gazetteers, archives, oral histories, maps, and satellite images, we documented the historical landscapes of ponds and wetlands back to the 17th century in the historic city of Huaiyang on the lower Yellow River floodplain. Like neighboring cities, Huaiyang was protected by a ring levee. As the floodplain rapidly aggraded, cities within the levee became topographically lower than the surrounding landscape. In this context, ponds and wetlands were essential for flood and storm water retention in the low-lying city. These seasonal waterbodies alternated between drying and wetting, providing a dynamic and diverse background for native habitats and human uses. CORONA satellite images ca. 1960s show ponds and wetlands shrinking in the dry season to 35.6% of their wet season extent, while the farmed area expanded 5.3 times. The multiple uses of wetlands included dry-season farming, harvesting wetland plants, and fishing, each use adapted to the localized topographic and hydrologic conditions of the wetlands. The late 20th century saw massive transformations for modern agriculture and urbanization. Understanding the historical evolution of this landscape can provide inspiration for developing green infrastructure and resilient designs that preserve cultural diversity and sustainably manage water in an urbanizing landscape. [ABSTRACT FROM AUTHOR]

The summer of 2022 was one of the hottest and driest summers that Germany experienced in the 21st century. Water levels in rivers sank dramatically with many dams and reservoirs running dry; as a result, fields could not be irrigated sufficiently, and even power generation and supply were affected. The impact of abnormally high temperatures for extended periods (heatwaves) is not restricted to nature and the economy but is also a considerable public health burden. Experts worldwide agree that these extreme weather events are being driven by climate change and will increase in intensity and frequency in the future. The adverse impact of these extreme weather events multiplies among dense urban environments, e.g., through heat islands. This calls for cities to take action to heat-proof and water-secure their urban developments. Water-Sensitive Urban Design (WSUD) is one such approach to mitigate the aforementioned challenges by leveraging the urban water ecosystem with special attention to the subject of water reclamation, retention, treatment and distribution. This paper introduces and builds upon a prototype of WSUD that centers around an artificial lake as an integrated water resource management system (IWRMS) fed by treated grey water and storm water obtained from two housing blocks flanking the water reservoir. Based on the specifications of this prototype, indicators of site suitability are derived and applied to identify potential locations for replicable projects in the city of Darmstadt. The results confirm the impact WSUD can have: a total of 22 sites with 2527 apartments are found suitable for prototype implementation in Darmstadt. Savings in town water consumption from these 22 sites would add up to 147 million liters. Further benefits include the provision of 24 million liters of irrigation water, storm water retention, adiabatic cooling during heatwave, increased biodiversity and the improvement in livability of the sites and the city. [ABSTRACT FROM AUTHOR]

Drought-resistant plants exhibit strong water retention capability. In this regard, the autotetraploid sour jujube leaves exhibit better water retention than diploid leaves. Morphological comparisons and physiological comparisons of diploid and autotetraploid leaves showed that the autotetraploid leaves had thicker leaf cuticles and more leaf wax accumulation than the diploid leaves, which could reduce cuticle permeability and improve the drought tolerance of leaves. In this study, the cuticular wax crystalloids on the adaxial and abaxial sides of young and mature jujube leaves were observed in the two ploidy types, and unique cuticular wax crystalloids covering a large area of the cuticle on autotetraploid sour jujube leaves may provide an advantage in reducing leaf non-stomata transpiration and improving plant drought tolerance. Based on the transcriptome, 115 differentially expressed genes between diploids and autotetraploids were further analyzed and found to be involved in the accumulation of cuticular wax components, including terpenoids, fatty acids, and lipids, as well as ABC transporter and wax biosynthetic process. Finally, 14 genes differentially expressed between glossy autotetraploid leaves and nonglossy diploid leaves, such as LOC107414787, LOC107411574 and LOC107413721, were screened as candidate genes by qRT-PCR analysis. This findings provided insights into how polyploidization improved drought tolerance. [ABSTRACT FROM AUTHOR]

looding is more common than earthquakes and hurricanes, leaving casualties, infrastructure damage, and economic losses in its wake. The October 2018 floods in Trinidad heightened public concern about the ability of public authorities to manage floods. This study investigates the impact of five combinations of detention basins and embankments on the cost of physical damage to residential buildings in the Caroni River Basin. Further comparison of the maximum flood depth before and after the implementation of structural mitigation combinations was conducted for typical design return periods of 5, 25, 50, and 100 years. The results showed that strategically introducing detention ponds along the Aripo and Guanapo Rivers caused the greatest reduction in flood damage cost (12.86%). Evidence also suggests that attenuation of flood waters by detention ponds is a better alternative to flood protection by embankmentonly options [ABSTRACT FROM AUTHOR]

Climate change and an increase in urbanization are severely testing urban drainage systems; at the same time, population growth is leading to an increase in demand for water resources, while climate change is more likely to reduce the amount of water that is available to meet this demand. The present study finds a solution to both problems by assuming a hybrid use of detention basins, i.e., providing a real-time control system (RTC) for the outfall discharge managed according to the rainfall forecast and the water level in the tank, to reuse rainwater for non-potable use and, at the same time, to guarantee the hydraulic protection of the downstream system. Twenty-seven scenarios were simulated using the numerical model SWMM 5.1, assuming different types of controls on the discharge. The simulations show a non-potable water-saving efficiency from a minimum of 32% to a maximum of 90%, and the reduction in volume discharged is between 11% and 31%, while the peak flow rate varies more significantly depending on the type of control used. These results highlight the detention basins' potential deriving from the hybrid use of this system with rainwater harvesting systems. [ABSTRACT FROM AUTHOR]

The Yellow River Plain (YRP), being regarded as the cradle of Chinese civilization, is traditionally thought to be the locale of the Great Flood, a hazardous flood (or floods) tamed by Yu who started China's first "dynasty", Xia, in ~ 2000 BC. However, by integrating published archaeological data, we propose that the Great Flood in fact impacted the Jianghan Plain (JHP) along the middle course of the Yangtze River. The arguments include: (1) around the era of the Great Flood, the most civilized and populated society in East Asia, named the Jianghan society, was located around the JHP (at that time, the habitation on the YRP remained limited); (2) the Jianghan society lived on river resources (shipping and rice growing) and was thus subject to flood risks (but not for the people inhabiting the YRP); (3) the people in the Jianghan society were experienced in dredging moats/ditches for shipping and irrigation; (4) unlike the floods on the YRP that were characterized by dynamic sedimentation and channel avulsion, those on the JHP typically occurred with slow-moving water manageable to ancient people; (5) the JHP has been associated with lake/wetland systems serving as detention basins during floods. Here, the recorded method for controlling the Great Flood, dredging channels to divert flood water to a "sea", was feasible. Known speleothem paleo-rainfall data from multiple sites show that the climate of the JHP had been wet since the middle Holocene (earlier than the era of the Great Flood) and significantly turned dry after ~ 1850 BC (~ 150 years later than the Great Flood). Thus, the uniqueness of the Great Flood was likely to reflect an increase in land use on the JHP with the expansion of the Jianghan society, and the success in taming this flood was mainly due to the efforts of the society, not by luck. Key points: Floods on the Jianghan Plain were predictable and manageable in ancient times. The most populated society in East Asia was located around the Jianghan Plain. The people in the Jianghan society were experienced in dredging moats/ditches. [ABSTRACT FROM AUTHOR]

Hazards associated with microplastics (MPs) and the pollutants they absorb in freshwater lake ecosystems have become a hot research topic in academia. In this study, in order to investigate potential affiliated MP hazards, lake MP samples were collected from a typical subtropical freshwater lake system in China (Poyang Lake) during the dry season (here, you should show the specific months) to explore their potential toxic element (PTE) response (i.e., exposure to Cu, Pb, and Zn) respective to the ecological environment and resident phytoplankton. Results show that average MP abundance in surface water can reach up to 1800 items m−3, which higher in the Nanjishan Wetland National Nature Reserve (NWNNR) (1175 items m−3). Polyester (i.e., purified terephthalic acid [PTA]) and polyethylene (PE) were the main polymer types found in surface water, fiber was the main MP shape, and most of the MP particle sizes are greater than 100 μm. Moreover, phytoplankton biomass was significantly higher in the NWNNR compared to Poyang Lake's retention basin and water channel. It indicated that MP pollutant status of Poyang Lake is mild; however, the ecological risks that MPs pose should not be ignored. The significant positive correlation between MPs and PTEs indicated that PTE absorption and desorption by MPs may cause potential ecological stress. Although we anticipate no direct link between ecotoxicity and phytoplankton, MPs may have indirect effects on phytoplankton through their regulatory effects on PTE levels in water. [ABSTRACT FROM AUTHOR]

Houston, Texas, has highly engineered its waterways to reduce flooding. However, this has been shown to be inadequate during recent storms in 2015 through 2017, including Hurricane Harvey. This study analyzed the efficacy of a large-scale structural mitigation project, Project Brays, on reducing flood levels in the Brays Bayou watershed given updated rainfall standards released in 2018. In addition, we investigated the water surface elevation (WSE) reduction of three detention basins that were constructed as a part of this mitigation project. We propose other possible detention basins to mitigate flood hazard in the highly flood-prone regions of the watershed. We found that Project Brays will decrease WSE in the upstream half of the watershed by around 1.2 m at the expense of increasing WSE by 0.52 m downstream. Additional detention basins could further decrease WSE by an average of 0.1 m over the area impacted during the Atlas 14 100-year storm. These impacts are very localized directly downstream of the detention locations and are no longer seen after approximately 300 m. Future mitigation should contain more localized detention directly upstream of flood-prone areas to provide additional targeted reductions in floodplain extent. Project Brays is a case study that demonstrates how future climate scenarios may be necessary for the large-scale design works of the future, given that such projects often take decades to construct and it is not typically standard practice to design for climate conditions potentially existing upon completion. [ABSTRACT FROM AUTHOR]

The Edwards Aquifer is the primary water resource for over 2 million people in Texas and faces challenges including fecal contamination of water recharging the aquifer, while effectiveness of best management practices (BMPs) such as detention basins in mitigating fecal pollution remains poorly understood. For this study, the inlet and outlet of a detention basin overlying the aquifer's recharge zone were sampled following storm events using automated samplers. Microbial source tracking and culture-based methods were used to determine the occurrence and removal of fecal genetic markers and fecal coliform bacteria in collected water samples. Markers included E. coli (EC23S857), Enterococcus (Entero1), human (HF183), canine (BacCan), and bird (GFD). Fecal coliforms, EC23S857, and Entero1 were detected following each storm event. GFD was the most frequent host-associated marker detected (91% of samples), followed by BacCan (46%), and HF183 (17%). Wilcoxon signed rank tests indicated significantly lower outlet concentrations for fecal coliforms, EC23S857, and Entero1, but not for HF183, GFD, and BacCan. Higher GFD and BacCan outlet concentrations may be due to factors independent of basin design, such as the non-point source nature of bird fecal contamination and domestic dog care practices in neighborhoods contributing to the basin. Mann–Whitney tests showed marker concentrations were not significantly higher during instances of fecal coliform water quality criterion exceedance, except for E. coli, and that fecal coliform concentrations were not significantly different based on marker detection. Overall, results suggest that the detention basin is effective in attenuating fecal contamination associated with fecal coliforms and the general markers, but not for host-associated markers. Consequently, management efforts should focus on mitigating dog and bird-associated fecal pollution in the study region. [ABSTRACT FROM AUTHOR]

Coastal regions are witnessing unsustainable aquifer overdrafts, leading to subsidence and increased flooding. Flooding introduces its own assortment of problems because managing substantial volumes of stormwater is often infeasible through surface storage in low-gradient areas. Aquifer recharge operations, such as aquifer storage and recovery (ASR), in conjunction with small-scale surface reservoirs, has the potential to supplement the function of flood retention basins and provide additional flood relief to local communities. The purpose of this study is to test the effectiveness of surface water capture and injection at the local watershed level in mitigating flood impacts. The study is based on using a hydrologic-hydraulic numerical modeling analysis for a pilot watershed that was found to be suitable for aquifer recharge operations in the coastal region of south central Louisiana in the US. The concept of capturing excess surface water and injecting into the subsurface was found most effective during storms with multiple flood peaks and was able to add more than 75% reduction in flood peaks compared with using a retention basin alone. A key finding is that diverting surface flows into the subsurface can be effective only when implemented in conjunction with intermittent storage. The results also showed that the benefit of such operations is realized in the case of storms that have multiple flood peaks. The results have implications on the use of subsurface injections via techniques such as ASR for flood mitigation, in addition to their original purpose for groundwater management and sustainability. [ABSTRACT FROM AUTHOR]

Additive manufacturing (AM), or 3D printing processes, is introducing new possibilities in electronic, biomedical, sensor-designing, and wearable technologies. In this context, the present work focuses on the development of flexible 3D-printed polyethylene glycol diacrylate (PEGDA)- sulfonated polyaniline (PANIs) electrically conductive hydrogels (ECHs) for pH-monitoring applications. PEGDA platforms are 3D printed by a stereolithography (SLA) approach. Here, we report the successful realization of PEGDA–PANIs electroconductive hydrogel (ECH) composites produced by an in situ chemical oxidative co-polymerization of aniline (ANI) and aniline 2-sulfonic acid (ANIs) monomers at a 1:1 equimolar ratio in acidic medium. The morphological and functional properties of PEGDA–PANIs are compared to those of PEGDA–PANI composites by coupling SEM, swelling degree, I–V, and electro–chemo–mechanical analyses. The differences are discussed as a function of morphological, structural, and charge transfer/transport properties of the respective PANIs and PANI filler. Our investigation showed that the electrochemical activity of PANIs allows for the exploitation of the PEGDA–PANIs composite as an electrode material for pH monitoring in a linear range compatible with that of most biofluids. This feature, combined with the superior electromechanical behavior, swelling capacity, and water retention properties, makes PEGDA–PANIs hydrogel a promising active material for developing advanced biomedical, soft tissue, and biocompatible electronic applications. [ABSTRACT FROM AUTHOR]

Wastewater stabilization ponds (WSPs) are used worldwide to treat wastewater from industrial and domestic sources because they are the most economical. However, the two main disadvantages are the colossal area required for the treatment facility and limited control over the effluent quality. The study compares pond designs with various baffle wall numbers and lengths in various configurations of ponds. The number of baffle walls analyzed was increased in even numbers from 0 to 10, and their length increased from 50% to 90% with a 10% increase every time. This study also examines how temperature affects treatment efficiency in various climatic regions of Turkey. The results reveal that increasing the number and length of baffle walls reduces design area and detention time and improves the effluent quality. It was also discovered that regions with warmer climates need less area and detention time than those with colder climates to remove a similar pollution load. In all regions except the Eastern Anatolia region, two out of three configurations analyzed in this study satisfied the country's class-B irrigation standards for eliminating fecal coliform and BOD5. Based on the analyses, configuration 1 (Anaerobic, facultative, and maturation ponds), having six baffle walls with 70 % length, is the optimum and suitable option for all regions. Lastly, comparing this research's outcome with experimental results is recommended. [ABSTRACT FROM AUTHOR]

Influenced by climate warming and human disturbance, the contradiction between flood control and water supply of the rivers-connected lake is becoming more prominent, and the prevailing dispatch system mainly aimed at flood control is a serious challenge for storage allocation. This paper presents a lake impoundment in advance method during flood recession period, which preliminarily explores the traditional dispatch model and couples it with a high-precision hydrodynamic model. A one- and two-dimensional coupled hydrodynamic model was constructed for integrated flood regulation in the "river-lake-flood detention basin" system. Then a sample library of water storage strategies was developed, which combined impounding times and gate operation schemes based on previous engineering experience. Thus, by combining large-scale numerical simulations of flood scenarios and risk-benefit assessment, the dispatching schemes facilitating the combined use of gates during the post-flood period under different wet-dry conditions were determined. The results show that: (1) the hydrological-hydrodynamic model has high accuracy for realizing the elaborate simulation of flood evolution and inundation dynamic between lands and lakes, with the average error controlled from 0.03 to 0.14 m, (2) the strategy extraction method of post-flood impoundment in advance for the lake basin is proposed, which takes the impounding times, gate scheduling rules, and inflow scenarios into account comprehensively, and (3) under the optimal storage strategies, the water storage efficiency is significantly improved, with the water level overrun rate controlled at 19.24%, the terminal storage level raised by 0.96 m, and the storage capacity increased by 17.0×108 m3 on average. The outcomes will provide support for flood control and water storage improvement during the post-flood period, which is beneficial to the utilization and management of flood resources. [ABSTRACT FROM AUTHOR]

The unsatisfactory nutrient slow-release and water-retention performance of traditional biochar-based compound fertilizers (BCF) severely limit their practical application. Herein, a new type of slow-release fertilizer with high water retention was fabricated via the incorporation of hydrotalcite and starch into BCF, named as HS-BCF. The water-retention and nutrient releasing performance of the prepared HS-BCF and related nutrient slow-release mechanism were investigated. The results showed that the incorporation of hydrotalcite and starch into BCF could increase the soil water-retention ratio by 5–10% points. The accumulated N, P, and K leaching amounts of HS-BCF in soil within 30 days were 49.4%, 13.3%, and 87.4% of BCF at most, respectively. Kinetic analysis indicated that the release of nutrients from HS-BCF was attributed to the coupling of the diffusion-controlled and relaxation-controlled mechanism. Moreover, hydrotalcite could bind with P in HS-BCF, contributing to the enhanced durability of P in HS-BCF. Finally, pot experiments showed that the N–P–K utilization efficiencies of HS-BCF were all higher than those of BCF due to a better synchronization between the nutrient release of HS-BCF and the uptake of tomato plants. Overall, the study may provide a promising strategy for simultaneously improving the water-retention and slow-release performance of traditional biochar-based fertilizers. Article highlights: A new biochar fertilizer was developed by incorporating hydrotalcite and starch. HS-BCF exhibited better water-retention and slow-release performance than BCF. The nutrient release of HS-BCF was diffusion and relaxation-controlled mechanism. The enhanced P durability of HS-BCF was partially due to the binding of hydrotalcite. [ABSTRACT FROM AUTHOR]

This study's primary goal was to conduct an analysis of the flood propensity of the Tabua (Ribeira Brava) drainage basin's main watercourse. In addition to that, this study also recommends two different methodologies in order to mitigate flood impacts, namely by dimensioning a detention basin and adjusting the riverbed roughness coefficient. Regarding the study on the flood propensity, it was necessary to resort to geomorphological data, which were obtained when characterizing the watershed; these data were crucial to determining the expected peak flow rate, according to the Gumbel distribution methodology and considering a 100-year return period, and to perform necessary tasks in the SIG ArcGIS 10.5 software. Lastly, the drainage capacity of this drainage basin's river mouth was also analyzed in order to conclude whether it would have the capacity to drain the total volume of rainwater if an extreme flood event were to happen. Indeed, the main results show that this watershed's river mouth does not have the necessary drainage capacity to cope with an extreme event for the return period that was considered. As a consequence, the two aforementioned mitigation measures were developed considering the Tabua (Ribeira Brava) drainage basin's specific features. The size of the detention basin was estimated through the Dutch method and the simplified triangular hydrograph method, while the adjustment of the roughness coefficient was considered a valid solution to enhance the drainage capacity of this river mouth. [ABSTRACT FROM AUTHOR]

This study's primary goal was to conduct an analysis regarding the flood susceptibility of the main watercourse of the São João (Funchal) drainage basin. In addition, if proven necessary, we also aimed to suggest mitigation measures, such as sizing a detention basin and promoting adjustments of the riverbed's roughness coefficient. This study also resorted to geomorphological data—obtained during the watershed characterization process—that were then utilized in the SIG ArcGIS software, in order to estimate the expected peak flow rate, considering a return period of 100 years using the Gumbel distribution. Finally, the Manning–Strickler equation was utilized to determine the river discharge point's drainage capacity; the reason for that was to verify whether its drainage capacity was sufficient to drain the entire volume of rainwater associated with an extreme flood event. In summary, the results obtained by this study indicate that the drainage capacity of the river discharge point of the São João watershed (Funchal) is insufficient when considering an extreme flood event, for a return period of 100 years. Hence, it became necessary to explore the two aforementioned mitigation measures: first, regarding the detention basin, its sizing was calculated through both the Dutch method and the simplified triangular hydrograph method; second, aiming to increase the drainage capacity of the river discharge point, it is suggested that the roughness coefficient should also be modified. [ABSTRACT FROM AUTHOR]

Floods are one of the most dangerous natural disasters, causing great destruction, damage, and even fatalities worldwide. Flooding is the phenomenon of a sudden increase or even slow increase in the volume of water in a river or stream bed as the result of several possible factors: heavy or very long precipitation, melting snowpack, strong winds over the water, unusually high tides, tsunamis, or the failure of dams, gages, detention basins, or other structures that hold back water. To gain a better understanding of flooding, it is necessary to examine evidence, search for ancient wisdom, and compare flood-management practices in different regions in a chronological perspective. This study reviews flood events caused by rising sea levels and erratic weather from ancient times to the present. In addition, this review contemplates concerns about future flood challenges and possible countermeasures. Thus, it presents a catalogue of past examples in order to present a point of departure for the study of ancient floods and to learn lessons for preparation for future flood incidents including heavy rainfalls, particularly in urbanized areas. The study results show that ancient societies developed multifaceted technologies to cope with floods and many of them are still usable now and may even represent solutions and measures to counter the changing and increasingly more erratic weather of the present. [ABSTRACT FROM AUTHOR]

The water and sediment characteristics of the Yellow River are related to the development of the river basin and have great significance in determining the future trends in sediment load. In this study, the water and sediment characteristics and influencing factors were analyzed. The correlations among hydrological and sediment parameters were further analyzed. The results showed that the annual average sediment concentration (AASC), the annual sediment load (ASL), the median grain size of sediment (MGSS) and the annual sediment transport modulus (ASTM) decreased. Therefore, the sediment control effect of the tributaries was significant. The annual runoff (AR) of the hydrological stations in the Yellow River increased from 2002 to 2019. Altogether, AASC and ASL of the Yellow River showed a downward trend. The sediment was reduced by water storage and sediment detention of reservoirs. AASC and ASL increased significantly due to water and sediment regulation tests and floods. However, the silt in the river channel could be washed with the help of current scouring and flood to slow down the silt. There was a strong correlation between AASC and ASL, whether the Yellow River or its tributaries. Besides, there was a significant impact of AASC and ASL of the tributaries on the sediment of the Yellow River, showing that the sediment control of the tributaries was essential. The sediment in the main tributaries and the Yellow River showed a decreasing trend from 2002 to 2019, which is conducive to the ecological harmony and stability of the Yellow River. [ABSTRACT FROM AUTHOR]

Copyright of Pearl River is the property of Pearl River Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Urbanization and climate change are producing an escalation in the prevalence of urban problems, particularly those connected to flooding, prompting authorities and stakeholders to recognize the need for sustainable solutions. Nature-Based Solutions are progressively replacing traditional engineering solutions as an alternative since they are more eco-friendly. By re-activating the urban hydrological cycle processes, NBS intends to increase the natural water storage capacity to help decrease urban flooding. The work described here outlines a framework for optimising the efficacy of NBS for flood risk reduction and its co-benefits, as well as defining the trade-offs among these co-benefits. The framework integrates 1D hydrodynamic models with multi-objective optimisation techniques. To demonstrate the applicability of the framework and its methods it has been used in Sint Maarten, which is an island located in the Caribbean Sea. Four NBS measure were identified as having good potential to be applied in the case study, namely: green roof, permeable pavement, bio-retention pond, and open detention basin. The results showed that the developed framework has the ability to represent the link between benefits and costs when evaluating various NBS, hence aiding the decision-making process to select and implement NBS. [ABSTRACT FROM AUTHOR]

Urban surfaces are often covered by impermeable materials such as concrete and asphalt which intensify urban runoff and pollutant concentration during storm events, and lead to the deterioration of the quality of surrounding water bodies. Detention ponds are used in urban stormwater management, providing two-fold benefits: flood risk reduction and pollution load minimization. This paper investigates the performance of nine proposed detention ponds (across the city of Renton, Washington, USA) under different climate change scenarios. First, a statistical model was developed to estimate the pollutant load for the current and future periods and to understand the effects of increased rainfall on stormwater runoff and pollutant loads. The Personal Computer Storm Water Management Model (PCSWMM) platform is employed to calibrate an urban drainage model for quantifying stormwater runoff and corresponding pollutant loads. The calibrated model was used to investigate the performance of the proposed nine (9) detention ponds under future climate scenarios of 100-year design storms, leading to identifying if they are likely to reduce stormwater discharge and pollutant loads. Results indicated significant increases in stormwater pollutants due to increases in rainfall from 2023 to 2050 compared to the historical period 2000–2014. We found that the performance of the proposed detention ponds in reducing stormwater pollutants varied depending on the size and location of the detention ponds. Simulations for the future indicated that the selected detention ponds are likely to reduce the concentrations (loads) of different water quality constituents such as ammonia (NH3), nitrogen dioxide (NO2), nitrate (NO3), total phosphate (TP), and suspended solids (SS) ranging from 18 to 86%, 35–70%, 36–65%, 26–91%, and 34–81%, respectively. The study concluded that detention ponds can be used as a reliable solution for reducing stormwater flows and pollutant loads under a warmer future climate and an effective adaptation option to combat climate change related challenges in urban stormwater management. [ABSTRACT FROM AUTHOR]

Wetlands play a vital role in ecosystems. They help in flood accumulation, water purification, groundwater recharge, shoreline stabilization, provision of habitats for flora and fauna, and facilitation of recreation activities. Although wetlands are hot spots of biodiversity, they are one of the most endangered ecosystems on the Earth. This is not only due to anthropogenic activities but also due to changing climate. Many studies can be found in the literature to understand the water levels of wetlands with respect to the climate; however, there is a lack of identification of the major meteorological parameters affecting the water levels, which are much localized. Therefore, this study, for the first time in Sri Lanka, was carried out to understand the most important parameters affecting the water depth of the Colombo flood detention basin. The temporal behavior of water level fluctuations was tested among various combinations of hydro-meteorological parameters with the help of Artificial Neural Networks (ANN). As expected, rainfall was found to be the most impacting parameter; however, apart from that, some interesting combinations of meteorological parameters were found as the second layer of impacting parameters. The rainfall–nighttime relative humidity, rainfall–evaporation, daytime relative humidity–evaporation, and rainfall–nighttime relative humidity–evaporation combinations were highly impactful toward the water level fluctuations. The findings of this study help to sustainably manage the available wetlands in Colombo, Sri Lanka. In addition, the study emphasizes the importance of high-resolution on-site data availability for higher prediction accuracy. [ABSTRACT FROM AUTHOR]

The article presents the discussion on desertification and land degradation in Africa. Topics include adverse impacts on human health, food security, economic activity, physical infrastructure, natural resources and the environment, with incidence in national and global security; and sustainable dryland management and restoration, the regeneration of natural vegetation as well as water retention and conservation measures.

Detention pond is a key storm water management measure employed both to attenuate surface runoff and to regulate depression storage, yet the effects of aquaculture ponds and reservoirs on runoff coefficient are not well quantified in a subtropical humid monsoon climate zone, China. Here, a set of six subcatchments ranging in size from 0.7 hm2 to 10,000 hm2 were evaluated over the 2011–2015 period. (i) The annual average runoff coefficient differed with different subcatchments due to the spatial heterogeneity of landscape patterns, while the event-based runoff coefficient under the same catchment showed a decreasing trend with increasing rainfall intensity. (ii) The annual average and event-based runoff coefficients initially increased and then decreased with an increase in the area ratio of aquaculture ponds and reservoirs. The critical area ratio of aquaculture ponds and reservoirs for the maximum runoff coefficient in annual, light, and moderate rainfall intensity was about 4%; but this value would be transferred forward to the position of < 4% under the intensity of heavy rain, rainstorms, and heavy rainstorms. (iii) All runoff coefficients decreased with increasing forestland but increased with increasing paddy fields, and the decreasing rate was greater than the increasing rate. The trends of runoff coefficient for the annual and event-based rainfall are opposite between river development coefficient and watershed shape coefficient. The results provide underlying insights for decision-makers in aquaculture land-use planning and the sustainable utilization of water resources in the upstream and downstream systems of a catchment. [ABSTRACT FROM AUTHOR]

Introduction Monitoring the changes in physical and hydraulic properties and stability of growth media due to root growth effects and wetting and drying cycles is important. Wetting and drying cycles can probably change physical characteristics, availability of water, air and nutrients for the plant and, as a result, might affect the growth and yield of the greenhouse plants. The growth period greatly affects the physical characteristics of the growth substrates; therefore, the watering of growth substrates should be managed according to these changes to avoid improper irrigation. Materials and Methods In this study, 14 growth media were prepared from individual substrates with different volumetric ratios. In order to evaluate the changes of growth media over the time (i.e., during consecutive irrigation events) in the greenhouse, 10 wetting and drying cycles were applied on the growth media in the lab. Several physical indicators including easily available water (EAW), air after irrigation (AIR), water buffering capacity (WBC) and water holding capacity (WHC) of the growth media were determined before and after the wetting and drying cycles. Besides, the subsidence, decrease of mass and decomposition of the growth media were determined over the time. Total porosity (TP), bulk density (BD), particle density (PD), pH and electrical conductivity of the mixtures were measured as well. Results and Discussion The pH values in the growth media varied from 5.72 to 6.94. The maximum pH value was related to sawdustsugarcane bagasse biochar produced at 300◦C vermiculite-zeolite, and wheat straw-vermiculite substrates, and the minimum value was related to the cocopeat-perlite substrate. The values of EC in the growth media varied from 0.21 to 1.43 dS mR². The highest and lowest EC values among the growth substrates were related to date palm bunches-vermiculite-rockwool and rockwool (0.2)-perlite substrates, respectively. The bulk density (BD) values of the growth media varied in the range of 0.163-0.401 Mg m-3. The values of total porosity (TP) of the growth media varied in the range of 64.8-82.8%v/v. The highest TP was related to the cocopeat-perlite substrate. The TP values of most of the substrates were greater than 70%v/v. The average values of EAW in the growth substrates ranged from 0.123 to 0.272 cm³ cm-3. The highest EAW was related to the sawdust-sawdust biochar produced at 500 °C vermiculite-zeolite substrate. The application of wetting and drying cycles increased EAW in most of the growth media. Therefore, it can be stated that the time had a positive effect on the EAW in most of the growth media. The average values of AIR before and after the application of wetting and drying cycles for the growth media varied in the range of 0.063-0.240 cm-3 cm³. The highest value of this indicator was observed in the sawdustdate palm bunches biochar produced at 300°C vermiculite substrate. In all substrates (with the exception of the sawdust-sawdust biochar produced at 500°C vermiculite-zeolite), the AIR increased after wetting and drying cycles. The range of WHC values before and after applying wetting and drying cycles was 0.4530.699 cm3 cm-3. The highest WHC belonged to the wheat straw-vermiculite substrate. The WHC values of five growth media, including cocopeat-perlite, decreased due to the application of wetting and drying cycles, and the WHC values of nine growth media decreased. The most stable substrate after the wetting and drying cycles was rockwool-sawdustvermiculite. The effect of time on the quantity of WBC was positive, so that with the application of wetting and drying cycles, the WBC values of most of the substrates increased. In all substrates, subsidence and dry weight reduction were observed after the wetting and drying cycles. These changes were low for the substrates with a high volumetric ratio of inorganic materials. The least change among the growth substrates in terms of decomposition (dry weight reduction) was related to the completely inorganic substrate rockwool (0.1)-perlite (%0.17). The most stable substrate in terms of subsidence after wetting and drying cycles was the rockwoolsawdust-vermiculite, which has a large volumetric ratio of individual inorganic substrates. The highest subsidence was observed in the substrates containing wheat straw (wheat straw-vermiculite and date palm bunches biochar produced at 300◦C wheat straw-vermiculite). The organic matter content in all the growth substrates decreased over time (after wetting and drying cycles). The decrease of organic matter in the substrates can be related to the decomposition of organic materials as a result of wetting and drying cycles. Conclusion The BD, TP, EAW and WHC of the majority of growth media were in the optimal ranges and for some mixtures even better than cocopeat-perlite. Wetting and drying cycles could affect the growth media through several processes such as decomposition of organic compounds, displacement and rearrangement of particles, fragmentation of particles, shrinkage, hardening and subsidence. The growth media with a high percent of organic substrates were unstable as compared with those containing a high proportion of inorganic substrates. In general, the wetting and drying cycles increased the frequency of micropores in the growth media. The wetting and drying cycles positively affected EAW, WHC, AIR and WBC of most growth media. These findings imply that wetting and drying cycles may improve the growth media according to the studied extensive variables. However, it is necessary to study the intensive variables such as hydraulic conductivity, oxygen diffusion and pore tortuosity in the growth media for better evaluation of the impact of wetting and drying cycles as well. [ABSTRACT FROM AUTHOR]

Evaluation of dike-break-induced flood risk has been a worldwide concern due to its enormous economic, environmental, and societal importance. The mitigation of flood risk in detention basins is a complex decision making process that could span multiple engineering and scientific disciplines. In this paper, an integrated dike-break-induced flood modeling, analysis, and management framework is proposed. The MIKE21-based numerical approach is first adopted to model the flood routing process in detention basins. With the physical behavior of the flood well understood, physics-informed approaches are proposed to better quantify the dike-break-induced flood risks, e.g., human life, economic and environmental losses, offering valuable information for engineers and policymakers to formulate targeted contingency plans. The Zhuhu detention basin in the Poyang Lake district in China is investigated using the proposed framework. The flood movement in the detention basin is first numerically simulated using the MIKE21-based model. Based on the results, i.e., inundation area, water depth, flow velocity, and arrival time of flood peak, the detention basin is divided into several flood disaster zones. The induced flood risks are then estimated for the different zones. Customized emergency evacuation plans are also formulated for the different flood disaster zones. The study of the Zhuhu detention basin confirms that the proposed framework effectively fuses numerical modeling, physics-informed analysis, and management of flood events, providing an integrated and enhanced decision making process for flood warning and risk mitigation in flood detention basins or at other places. [ABSTRACT FROM AUTHOR]

The soil water retention curve (SWRC) is a key soil property required for predicting basic hydrological processes. SWRC is often obtained in laboratory with non-harmonized methods. Moreover, procedures associated to each method are not standardized. This can induce a lack of reproducibility between laboratories using different methods and procedures or using the same methods with different procedures. The goal of this study was to estimate the inter/intralaboratory variability of the measurement of the wet part (from 10 to 300 hPa) of the SWRC. An interlaboratory comparison was conducted between 14 laboratories, using artificially constructed, porous and structured samples as references. The bulk densities of samples were different at the very beginning of the experiment. This resulted in a variability of retention properties between the samples, which was estimated by a linear mixed model with a 'sample' random effect. Our estimate of inter/intralaboratory variability was therefore not affected by intrinsic differences between samples. The greatest portion of the differences in the measurement of SWRCs was due to interlaboratory variability. The intralaboratory variability was highly variable depending on the laboratory. Some laboratories successfully reproduced the same SWRC on the same sample, while others did not. The mean intralaboratory variability over all laboratories was smaller than the mean interlaboratory variability. A possible explanation for these results is that all laboratories used slightly different methods and procedures. We believe that this result may be of great importance regarding the quality of SWRC databases built by pooling SWRCs obtained in different laboratories. The quality of pedotransfer functions or maps that might be derived is probably hampered by this inter-/intralaboratory variability. The way forward is that measurement procedures of the SWRC need to be harmonized and standardized. [ABSTRACT FROM AUTHOR]

The effect of climate/environmental change has resulted in adverse water stress conditions which necessitates the sustainable approaches for improving the water use efficiency to boost agricultural production in Central Asia. Water-absorbing polymer (WAP) has emerged as one of the amendments for soil water stress management. WAP are chemically cross-linked structure capable of absorbing and storing a large amount of water. The agricultural land has different levels of fertilizers which can influence the performance of WAP because of its sensitivity due to external ionic medium. Therefore, the combined or hybrid use of WAP and organic/inorganic fertilizers may inhibit the functionality of WAP, which needs to be thoroughly investigated. This study demonstrates the performance of two different WAPs (a commercially WAP (crosslinked potassium polyacrylate) and a laboratory synthesized WAP (crosslinked fly ash-polyacrylate superabsorbent composite)) with varying combinations of fertilizers in silt loam (agrarian soil). The combined use of fertilizers and WAP have improved the water retention properties of soils due to modification in the soil pore volume for both the WAPs. Quantification from water retention properties revealed a significant increase in plant wilting time (PWT) and plant available water content (PAWC) under the combined influence of fertilizers and WAP amended soils, indicating the possibility of high-water availability to plant roots. The study suggests the potential of WAPs as an efficient soil conditioner even in the presence of fertilizer for countering the negative impacts of water stress conditions. WAPs might minimize the requirement for chemical fertilizers, which helps to enhance the climate/environmental change and agriculture sector in the Central Asian region. [ABSTRACT FROM AUTHOR]

The Yellow River Plain (YRP), being regarded as the cradle of Chinese civilization, is traditionally thought to be the locale of the Great Flood, a hazardous flood (or floods) tamed by Yu who started China's first "dynasty", Xia, in ~ 2000 BC. However, by integrating published archaeological data, we propose that the Great Flood in fact impacted the Jianghan Plain (JHP) along the middle course of the Yangtze River. The arguments include: (1) around the era of the Great Flood, the most civilized and populated society in East Asia, named the Jianghan society, was located around the JHP (at that time, the habitation on the YRP remained limited); (2) the Jianghan society lived on river resources (shipping and rice growing) and was thus subject to flood risks (but not for the people inhabiting the YRP); (3) the people in the Jianghan society were experienced in dredging moats/ditches for shipping and irrigation; (4) unlike the floods on the YRP that were characterized by dynamic sedimentation and channel avulsion, those on the JHP typically occurred with slow-moving water manageable to ancient people; (5) the JHP has been associated with lake/wetland systems serving as detention basins during floods. Here, the recorded method for controlling the Great Flood, dredging channels to divert flood water to a "sea", was feasible. Known speleothem paleorainfall data from multiple sites show that the climate of the JHP had been wet since the middle Holocene (earlier than the era of the Great Flood) and significantly turned dry after ~ 1850 BC (~ 150 years later than the Great Flood). Thus, the uniqueness of the Great Flood was likely to reflect an increase in land use on the JHP with the expansion of the Jianghan society, and the success in taming this flood was mainly due to the efforts of the society, not by luck. [ABSTRACT FROM AUTHOR]

In Brasilia, the local regulations limit the maximum flow rate per unit area discharged in rivers by drainage systems. The purpose of this work is to analyze the possibility of optimizing the use of an existing detention pond, known to be oversized, by directing to it the stormwaters of adjacent areas not attended by any urban drainage system. SWMM (Storm Water Management Model) is a hydrologic and hydraulic model that was used to design a new urban drainage system for this added area and to analyze the basin with the detention pond at the outlet. As a result, the new system designed complies with all local regulations including maximum flood peak for the design critical rainfall. However, the original drainage system for the area needs improvements considering that there were flooded manholes for all rainfall events tested - clearly seen with the 2D modelling. If adapted, the existing detention pond is sufficient for the proposed adjacent area. This study showed the importance of hydrological and hydraulic modelling in urban drainage to manage this system and to propose sustainable measures - such as ponds. It was also revealed that the benefits of these ponds are related to the damping of the peak flow and if located at the end of the drainage system, floodings on the area may still occur. [ABSTRACT FROM AUTHOR]

As a result of poor human activities, storm water is now contaminated, notably in the Middle East. The filtering process is a physical separation with no chemical reactions occurring throughout the operation. The goal of this research is to use three distinct types of filters to improve the quality of storm water: sand, sand with granular activated carbon (GAC), and sand with cotton. Before and after treatment, the pH, turbidity, electric conductivity, TDS, and temperature of storm water are all monitored. In addition, the water quality index (WQI) was computed. The parameters of treated storm water varied depending on the filter media used, such as sand (turbidity = 83 NTU, TDS = 585 mg/L, conductivity = 1190 S/cm, pH = 7.1 and temperature =17.8 °C), sand with GAC (turbidity = 12NTU, TDS = 540 mg/L, conductivity = 910 S/cm, pH = 7 and temperature =18 °C) and sand with cotton (turbidity = 6.4 NTU, TDS = 490 mg/L, conductivity = 1090 µS/cm, pH = 7.2 and temperature =17.6 °C). Sand has a treatment efficiency of 63.6 percent, sand with GAC has an efficiency of 84.9 percent, and sand with cotton has an efficiency of 84.2 percent at a flow rate of 0.66 L/min, when WQI is clean. With GAC, it is clear that the dual media filter is the finest special sand. [ABSTRACT FROM AUTHOR]

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Permeable concrete pavements are becoming more common as a stormwater management system to mitigate urban flooding. However, they have several well-defined drawbacks including low permeability, high clogging potential, and low strength and durability, notably in cold climates exposed to freezing and thawing. A new generation of high-strength clogging-resistant permeable pavement replacement (CRP) has been developed, through extensive laboratory work, to address these shortcomings and advance the field of permeable pavements. This paper reports on new advances in permeable pavement systems and the performance of a range of conventional permeable concrete and the developed novel CRP (both prepared using Portland cement) of varying porosity exposed to freeze–thaw cycles. This will allow performance evaluations of both systems in a cold climate. The tests involved exposing samples to temperatures varying from −20°C to +20°C and measuring changes in mass, area, compressive strength, and ultrasonic pulse velocity after each cycle. These new results show that CRP is highly resistant to degradation caused by freeze–thaw cycles compared to conventional permeable concrete, reducing maintenance requirements and improving service life. This study presents the first high-strength clogging-resistant permeable pavement replacement that is durable under frost action, these findings will support and enable wider use of permeable pavements in cold regions. [ABSTRACT FROM AUTHOR]

Hydraulic behavior and pollutant removal efficiency of three stormwater end-of-pipe control structures were evaluated and compared. Three detention basins (wet, dry, and semi-dry, i.e. dry with a wet central channel) were monitored within three sites of Southern Quebec, Canada. Water samples were collected upstream and downstream of the basins and analyzed for total suspended solids (TSS), nitrogen, total phosphorous, and ions related to de-icing salts. Generalized linear models and hydrological/hydraulic (SWMM) models were developed to compute the long-term TSS and total phosphorous load removal efficiency for two of the studied basins. Results indicate that even when considering uncertainties, removal rates are the highest for the wet basin and the lowest for the dry one. The addition of a wet channel in the semi-dry basin leads to higher removal efficiency than in the dry basin (e.g. median TSS concentration removal of 69% and 14%, respectively, for the semi-dry and dry basins). [ABSTRACT FROM AUTHOR]

Artificial ponds can act as crucial buffers against nitrogen (N) pollutants within agricultural landscapes. Despite the recognized dominance of biogeochemical N removal for N retention by artificial ponds, the mechanisms underlying the coupling of nitrification and denitrification remain little studied. Here, we present an isotope study exploring the N retention patterns in both water and sediments from several artificial ponds across a hilly watershed in southwestern China. We found distinct N retention by the study ponds showing low levels of NO 3 − in water (0.5 ± 0.3 mg N L–1), but high levels of NH 4 + (24.9 ± 7.5 mg N kg–1) and organic N (ON, 0.3% ± 0.1%) in sediments. Isotope signatures of NO 3 − of pond water (δ15N NO3− , –8.5‰–31.9‰; δ18O NO3− , 2.7‰–18.6‰) show considerable N inputs from N fertilizer, manure, and sewage, confirming the pivotal role of artificial ponds as effective mitigators of anthropogenic pollutants within the watershed. Combining N isotopes of ON, NH 4 +, and NO 3 − in sediments and isotope fractionation effects, we estimated the proportional progress of nitrification (f nit , 6.9% ± 4.4%) and denitrification (f den , 48.7% ± 4.1%). The significantly positive correlation between f den and f nit indicated tightly coupled nitrification and denitrification during the N removal, which also contributed to the high NH 4 +/NO 3 − ratios detected in sediments. Across those artificial ponds, variations in surface area and water depth associated with the hilly topography could affect C/N ratios in the sediment, thereby governing the progression of both nitrification and denitrification. Therefore, the spatiotemporal heterogeneity of N retention by artificial ponds from that region necessitates further attention, especially in establishing the connection between hydrogeochemical N nutrient flow and biogeochemical N turnover in the dispersed water bodies. Our results pinpoint the importance of the N sink function shown by artificial ponds in the hilly watersheds of southwestern China, which serve as functional units in buffering regional N pollutants from agricultural runoff. [Display omitted] • Distinct N retention of artificial ponds was observed in a hilly agricultural region. • The nitrification and denitrification in sediments were isotopically evaluated. • The C/N ratio is important in influencing N removal processes of artificial ponds. [ABSTRACT FROM AUTHOR]

Biocides used in paints and renders prevent algae and fungi growth but can wash off during wind-driven rain and enter urban environments. Retention ponds represent part of storm water management that retain water and partly pollutants. However, it is poorly understood which percentage of biocides leached from facades reaches a pond and how efficiently biocides are retained inside ponds although biocides can have harmful environmental effects. Here, we combined measurements and modeling to address diffuse biocide loss and a pond’s retention capacity in a delimited residential area of 3 ha, with detached houses connected to an ephemeral retention pond. Six storm water events were sampled within 2 years and confirmed biocidal residuals at pond inflow. Model results revealed that during the sampled events only 11% of terbutryn leachate arrived at the pond while the major part of this biocide was diffusely lost in the residential area. Measured low terbutryn concentrations in the sediment (mean 2.6 ng g-1 ) confirmed this result. Model results suggested that approximately 50% of terbutryn reaching the pond were retained and degraded. Our results are site-specific but suggest that biocide retention in ponds is limited, environmental entry pathways are diverse and that biocide use should be limited at its source. [ABSTRACT FROM AUTHOR]

The availability of water for agricultural use in the savannah plateau of Adamawa, Cameroon, is addressed in this paper. Specific field tests coupled with climatic data analysis have helped to characterize the hydrological and hydrogeological conditions of water resources in a small catchment. An agricultural suitability map, based on the water availability during the dry season, is produced. Measured saturated hydraulic conductivities indicated an acceptable disposition of the soils for agriculture. The transmissivity values indicated moderate groundwater potential with mean annual recharge of 96 mm. The agricultural suitability map shows that only 8.8% of the basin area is very favorable for agriculture and that 51% of the basin is not suitable for agriculture, due to water scarcity during the dry season. Due to the considerable depth to the water table, pumping for irrigation purposes is not affordable for the local low-income farmers. Therefore, there is a need to implement adapted solutions for irrigation to support farmers' endeavors, such as the development of water retention basins or the construction of boreholes equipped with electric pumps supplied by solar energy for irrigation. [ABSTRACT FROM AUTHOR]