Search

Indonesia, a country with high forest and land potential for economic growth, still relies on utilizing these two potentials. This study aims to create a conservation scenario in palm oil plantations that are expected to be able to mitigate surface runoff. The data collected include hydrology, land, area of oil palm plantations, and topography, which were analyzed based on threats and potential conservation that can be applied. Conservation scenarios that need to be carried out are: deadlock alley ditch (dad), mixed tree and palm oil plantations, planting oil palm without land cultivation, and immersing mulch. The simulation results of the dad design, if it rains heavily, all of the rainwater in the palm oil fields can be accommodated without a runoff. Mixed tree and oil palm plants are expected to maintain the availability of nutrients, increase the income of oil palm smallholders, and have a good impact on soil fertility. Planting oil palm without land cultivation is expected to reduce surface runoff, increase water infiltration into the soil, and expand water catchment areas. The immersion of palm mulch is expected to help retain soil moisture, add nutrients, enhance the soil's ability to absorb water, and prevent erosion. Conservation scenarios in the long term, such as dad, mixed tree and oil palm plantations, oil plantations without land cultivation, and mulch immersion, are expected to be able to mitigate flooding. [ABSTRACT FROM AUTHOR]

The change in land use and land cover (LULC) due to human activities is a major cause of hydrological process changes in watersheds. This study assesses the effects of LULC changes on the hydrological processes in the Bilate catchment, located in southern Ethiopia. Landsat images of 1986, 2002, and 2018 were used to classify LULC through supervised classification. The Soil and Water Assessment Tool (SWAT) evaluated the hydrological responses to LULC changes. Results indicate an increase in built-up areas (0.70%), water bodies (0.19%), cultivated land (10.54%), and barren land (1.265%) from 1986 to 2018. Conversely, the forest (8.52%) and grazing (3.18%) areas declined. An increase in water leaving the root zone (962.02 mm/year), potential evapotranspiration (593.85 mm/year), actual evapotranspiration (201.71 mm/year), and surface runoff (514.86 mm/year) was observed, while soil water content (1423.25 mm/year) decreased at the catchment level. The declining soil water content and increasing actual and potential evapotranspiration could result in a water shortage for crop production. The impact of LULC changes on hydrology provides vital knowledge for integrated LULC and water resource management. Water resource development planning must consider LULC changes to achieve sustainable development in the catchment. [ABSTRACT FROM AUTHOR]

Predicting suspended sediment load is essential to identify its intensity and define necessary actions for its reduction. Mathematical models simulating suspended sediment load are an interesting tool for this purpose. The methodological approach adopted in this article consists in looking for a regressive model that can better explain the suspended sediment discharge through flow discharge by studying this relationship at different temporal scales. The work comprises analyzing and quantifying the suspended sediment intakes conveyed by the El-Malah East river at the Beni Slimane gauging station towards the Koudiat Acerdoune reservoir. The available data covers the period from 1973/74 to 1988/1989 for instantaneous measurements of liquid flow discharge Ql - Suspended sediment concentration C and the period from 1985/86 to 1996/97 for daily mean flow discharges and daily mean precipitations. Only power relations obtained on a seasonal scale giving the best coefficient of determination have been selected for the quantification of suspended sediment load conveyed by El-Malah river at Beni Slimane hydrometric station in the period of availability of daily mean flow discharges (1985/86 to 1996/97). The optimization of suspended sediment rating curves has been validated by comparison of the estimated values with the observed data and by fitting Normal distribution to residues datasets. The use of these models has highlighted an intra-annual distribution of the suspended sediment contributions conveyed by the El-Malah East river at Beni Slimane hydrometric station estimated at 0.088 Mt per year, representing a specific degradation of about 325 t.km-2y-1 (423 t.km-2y-1 of suspended and bed loads). The results have also shown that the highest liquid intake occurs in spring (45.72 %), winter (32.36 %) and autumn (11.93 %) seasons. This distribution, as well as the distribution of the monthly rainfalls, allowed the conclusion that the runoff period does not always correspond to the rainy period. The highest precipitation occurs in winter (38.74 %), spring (32.25 %) and autumn (21.53 %) seasons. The intra-annual distribution of suspended sediment contributions showed that winter and autumn participate in each one with 28.31 and 27.03% of the total suspended sediment load annually, while summer and spring participate with 23.28 and 21.38 %, respectively. The obtained results can be verified and improved by increasing the size of the available series. They provide appreciable elements of comparison for others basins of the same order, located in semi-arid and arid regions and subjected to similar phenomena. They also allow river basin managers and policymakers to consider necessary actions to fight against land erosion, preserve human activities, increase the life of the Koudiet Acerdoune dam 60 km downstream from the watershed outlet, facilitate decision-making and planning, and ensure effective management. [ABSTRACT FROM AUTHOR]

World Soil Day 2021 encouraged the prevention of soil salinization and improved land productivity. As research underpins this effort, we analysed trends in research on water and salt mobilization in saline soils and groundwater over the past 20 years. We found that the average studies have increased by 30%, from 110 in 2003–2015 to 143 in 2016–2022, with agriculture, water resources and environmental science being the main research fields. The most common research interests were anthropogenic impact (28.6%) and climate change (27.8%), followed by agricultural irrigation management (20%). A keyword clustering analysis revealed that the studies could be classified into four categories: "Agricultural production," "Freshwater and groundwater salinization," "Seawater intrusion," and "Solute dynamic migration." The most frequently used keyword was "transport" while the use of "freshwater," "groundwater," and "seawater intrusion" has increased sharply, suggesting that seawater intrusion and freshwater salinization are an area of increasing interest related to climate change. We identified comprehensive simulating systems for seawater intrusion as an important area for future research. We recommend that promoting a comprehensive and quantitative understanding of water and salt transport in saline soil is needed to ensure stakeholders are provided with science‐based information required for policymaking aimed towards sustainable development. [ABSTRACT FROM AUTHOR]

The SCS‐CN, Horton and USLE‐family models are used worldwide, but few examples are available for olive groves on steep and clayey soils under mulching of pruning residues. We evaluate the accuracy in predicting runoff and soil loss of a steep (20%) and clayey olive grove subject to three soil conservation practices: mechanical tillage (MT), mulching with pruning residues (NTR) and standard protection (SP), measured at plot scale in Southern Italy during 30 months under natural rainfall. The models were calibrated by adjusting the Curve Numbers (for the SCS‐CN model) and the C‐factors (MUSLE and USLE‐M); the Horton model was not calibrated. The model performance was assessed by qualitative and quantitative procedures. In all practices, the SCS‐CN was more accurate for runoff predictions (mean difference of 7% compared with corresponding observations) compared with the Horton (mean difference of 30%). For soil erosion, the MUSLE showed better performance in soils subject to MT or total protection (differences lower than 10%), while the USLE‐M was more reliable to simulate soil loss in mulched plots (differences of 8%). A set of Curve Numbers (95 for MT, 70 for SP and 85 for NTR) and C‐factors (0.4 for MT, 0.2 for SP and 0.1 for NTR) are proposed for applications in steep slope and clayey soil olive orchards using the SCS‐CN and USLE proposed models, respectively. Validation exercises in other environmental experimental conditions would enhance the export these models for runoff and erosion control in agricultural soils treated with mulching. [ABSTRACT FROM AUTHOR]

Soil erosion by water is influenced by a major morphogenetic factor -- precipitation. Surface runoff, initiated by rainfall, plays a key role in this process. This article addresses the effects of rainfall intensity and soil moisture on soil erosion through a series of rainfall simulations of different intensity and duration. The implementation of measurements at a research station located in the Różany Stream catchment in Poznań made it possible to study the entire water balance within the slope, including precipitation, evaporation, surface runoff and infiltration. The study included various rainfall intensities, with a focus on extreme events reflecting ongoing climate change and increasing anthropopressure. Rainfall simulations were conducted on both dry and wet ground. The results showed that increasing rainfall intensity led to greater surface runoff and soil loss. Moreover, soil moisture was identified as a critical factor affecting soil erosion, with wetter conditions reducing soil loss while increasing surface runoff. [ABSTRACT FROM AUTHOR]

Land cover change is prevalent in the eastern Kentucky Appalachian region, mainly due to increased surface mining activities. This study explored the potential change in land cover and its relationship with stream discharge and sediment yield in a watershed of the Cumberland River near Harlan, Kentucky, between 2001 and 2016, using the Soil and Water Assessment Tool (SWAT). Two land cover scenarios for the years 2001 and 2016 were used separately to simulate the surface runoff and sediment yield at the outlet of the Cumberland River near Harlan. Land cover datasets from the National Land Cover Database (NLCD) were used to reclassify the land cover type into the following classes: water, developed, forest, barren, shrubland, and pasture/grassland. Evaluation of the relationship between the land cover change on discharge and sediment was performed by comparing the average annual basin values of streamflow and sediment from each of the land cover scenarios. The SWAT model output was evaluated based on several statistical parameters, including the Nash–Sutcliffe efficiency coefficient (NSE), RMSE-observations standard deviation ratio (RSR), percent bias (PBIAS), and the coefficient of determination (R²). Moreover, P-factor and R-factor indices were used to measure prediction uncertainty. The model showed an acceptable range of agreement for both calibration and validation between observed and simulated values. The temporal land cover change showed a decrease in forest area by 2.42% and an increase in developed, barren, shrubland, and grassland by 0.11%, 0.34%, 0.53%, and 1.44%, respectively. The discharge increased from 92.34 mm/year to 104.7 mm/year, and sediment increased from 0.83 t/ha to 1.63 t/ha from 2001 to 2016, respectively. Based on results from the model, this study concluded that the conversion of forest land into other land types could contribute to increased surface runoff and sediment transport detached from the soil along with runoff water. The research provides a robust approach to evaluating the effect of temporal land cover change on Appalachian streams and rivers. Such information can be useful for designing land management practices to conserve water and control soil erosion in the Appalachian region of eastern Kentucky. [ABSTRACT FROM AUTHOR]

Due to higher levels of urbanization and increasing impermeable hard land covers, green spaces are decreasing, resulting in stormwater loss as surface runoff instead of being absorbed by soil and reintroduced into the water cycle. This study investigates the effect of land use ratios and land cover materials resulting from settlement design on surface runoff volume. The study was conducted using various scenarios in 9 settlements with different land use ratios, including roofs, sidewalks, parking areas, roadways, and green areas in Istanbul, a city with a high urbanization rate. Thus, surface runoff volume in settlements depending on the land use ratios was evaluated. A total of 336 material combinations were developed using various material alternatives in addition to different land use ratios. Therefore, the effect of different land cover materials used in the settlements on surface runoff volume was also evaluated. Study requirements were taken into consideration when choosing the calculation method, and the Rational Method, often preferred for calculating surface runoff volumes in small urban basins, was chosen. According to the calculation results obtained from the settlements developed for this study, surface runoff volume can be reduced by 37.10 % by increasing only the green space ratio and by 67.65 % by using different material alternatives in the same settlement. Additionally, it was observed that each improvement made to reduce surface runoff in settlements resulted in a positive change. • Building forms and settlement design are parameters that directly affect surface runoff. • Surface runoff volume changes depending not only on the land use ratio of settlements but also on land cover materials. • Surface runoff volume can be significantly decreased by increasing green spaces in settlements. • Settlements with low green areas but permeable covers may outperform those with high green areas but impermeable covers. [ABSTRACT FROM AUTHOR]

[Display omitted] • Rock surface flow inputs promote the generation of surface runoff at the CRSI. • Concave shapes tend to promote surface runoff formation more than straight shapes. • CRSI has lower soil water infiltration and storage capacity than FRSI. • Discriminant conditions for rock surface flow to generate surface runoff were set. Rock surface flow, formed from exposed rock surfaces, is a unique form of runoff in rocky desertified areas with massive bedrock outcrops. The question of whether the rock surface flow promotes surface runoff formation continues to puzzle us. To address this problem, four sites with notable bedrock outcrops and different land use types were selected from a typical desertified area in Guizhou, China. Straight and concave rock-surface shapes that were the most capable of collecting rainwater were selected at each site. Soil infiltration and water storage capacity experiments were conducted to observe the infiltration and water storage properties of the soil closely adhering to the rock–soil interface (CRSI) of the bedrock outcrops by taking the soils far from the outcrops horizontally (FRSI) as the control, and to further explain the conditions for surface runoff formation via rock surface flow. Our results showed that the CRSI is more prone to producing surface runoff than the FRSI, which is attributed to its lower infiltration (stable infiltration rate of 0.2 to 192.6 mm/min) and water storage capacity (total reservoir 441.6 to 613.6 t/hm2) than that of FRSI (4.50 to 272.8 mm/min, 458.8 to 635.4 t/hm2). This phenomenon would be intensified after receiving the rock surface flow input. Concurrently, concave rock surfaces are more likely to promote surface runoff formation than straight rock surfaces, which are affected by the accumulation of rock surface shapes on rainwater. A discriminating condition for whether rock surface flow produces surface runoff at the CRSI is proposed based on the inversely proportional functional relationship between rainfall (rainfall intensity R I and amount R A) and the effective rock surface rainfall catchment area (A RS). When R I or R A exceeds the critical threshold, the surface runoff with mechanisms of excess infiltration or excess saturation is generated around bedrock outcrops. The discriminating equation will help increase surface runoff prediction accuracy in rocky desertified areas with exposed bedrock outcrops. These results help understand the importance and role of rock surface flow hydrologic processes in karst areas. [ABSTRACT FROM AUTHOR]

Agriculture is a major driver of land-use change and nutrient leaching worldwide, promoting eutrophication of surface water bodies. A frequent strategy to reduce nutrient external loads is the maintenance or re-establishment of riparian zones. We conducted a year-long, in situ monitoring of surface and subsurface water in three buffer zones (grassland, shrubland, forest) and adjacent croplands around the major water reservoir in Uruguay to assess runoff dynamics and nutrient potential reduction across different precipitation levels. All three buffer zones delayed surface runoff by twofold, yielding lower runoff than croplands. Also, they effectively retained phosphate (P-PO 4) loads in both surface and subsurface runoff but were less effective in reducing their concentrations. The forest achieved the highest surface water P-reduction (80%). The effect was variable for nitrate (N-NO 3), with buffers acting as either nutrient sinks or sources depending on the vegetation and runoff layer. Surface N-NO 3 loads were lower in the buffers, with a maximum reduction in grassland (∼50%), when compared to crops. In the subsurface layer, a reduction was only observed for N-NO 3 concentration in grassland (30%). Surface TP and P-PO 4 loads increased linearly with runoff rate only in the buffers, while both N-NO 3 and ammonium (N-NH 4) loads increased with runoff in both crops and buffers. Our results may indicate that riparian buffers comprised of herbaceous and woody vegetation have high phosphorus and nitrogen reduction rates, emphasizing their potential as nature-based solutions for nutrient mitigation and water storage. Future increased precipitation may, however, challenge buffer effectiveness. • Different vegetated buffer zones could vary in agricultural runoff mitigation. • Forest, shrubs and grassland buffers retained surface and subsurface runoff nutrients. • Forest cover enhanced P retention; grassland had the greatest effect on N dynamics. • Mixed herbaceous and woody riparian buffers yielded higher nutrient retention. • Projected higher precipitation may reduce buffer capacity for nutrient retention. [ABSTRACT FROM AUTHOR]

The watershed hydrologic conditions in the Madre de Dios (MDD) Basin in the Peruvian Amazon have been irreversibly impacted by deforestation and changes in land cover. These changes have also had detrimental effects on the geomorphology, water quality, and aquatic habitat within the basin. However, there is a scarcity of hydrological modeling studies in this area, primarily due to the limited availability of hydrometeorological data. The primary objective of this study was to examine how deforestation impacts the hydrological conditions in the MDD Basin. By implementing the Soil and Water Assessment Tool (SWAT) model, this study determined that replacing 12% of the evergreen broadleaf forest area with bare land resulted in a significant increase in surface runoff, by 38% monthly, a 1% annual reduction of evapotranspiration, and an average monthly streamflow increase of 12%. Changes in spatial patterns reveal that the primary impacted watershed is the Inambari River subbasin, a significant tributary of the Madre de Dios River. This area experiences an annual average surge of 187% in surface runoff generation while witnessing an annual average reduction of 8% in evapotranspiration. These findings have important implications, as they can contribute to instances of flooding and extreme inundation events, which have already occurred in the MDD region.

This study assesses the impacts of climate variability on surface runoff generation in the Mouhoun River Catchment (MRC) in Burkina Faso, in the West African Sahel. The study uses a combination of observed and reanalysis data over the period 1983–2018 to develop a SWAT model (KGE = 0.77/0.89 in calibration/validation) further used to reconstitute the complete time series for surface runoff. Results show that annual rainfall and surface runoff follow a significant upward trend (rainfall: 4.98 mm·year−1, p-value = 0.029; runoff: 0.45 m3·s−1·year−1, p-value = 0.013). Also, rainfall appears to be the dominant driver of surface runoff (Spearman’s ρ = 0.732, p-value < 0.0001), leading surface runoff at all timescales. Surface runoff is further modulated by potential evapotranspiration with quasi-decadal timescales fluctuations, although being less correlated to surface runoff (Spearman’s ρ = −0.148, p-value = 0.386). The study highlights the added value of the coupling of hydrological modeling and reanalysis datasets to analyze the rainfall–runoff relationship in data-scarce and poorly gauged environments and therefore raises pathways to improve knowledge and understanding of the impacts of climate variability in Sahelian hydrosystems.

【Objective】 Nitrogen loss from terrestrial ecosystems is an environmental concern in many countries. It is affected by a multitude of biotic and abiotic factors. The purpose of this paper is to investigate the efficacy of soil amendment with straw in ameliorating nitrogen loss from watersheds in the Huaihe River basin. 【Method】 The experiment was conducted indoors using drab soil taken from the field. Artificial rainfall at intensity of 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 mm/min were applied over the surface of soil amended with crop straw. Water and sediment runoffs from the soil surface, as well as nitrogen loss from both surface and subsurface runoff in each treatment were measured. 【Result】 Accumulative sediment runoff and nitrogen loss from the soil both increased with the rainfall intensity. The nitrogen concentration in the runoff changed more erratically in the first 20 minutes after the commencement of the rainfall, characterized by a rapid increase followed by a long tailing in all treatments. The average nitrogen concentration in the runoff measured from soil without straw amendment peaked when the rainfall intensity was 2.0 mm/min followed by 3.0 mm/min, while amending the soil with straw reduced this to 1.5 mm/min. The amount of nitrogen loss via sediment runoff accounted for 92.8% of the total loss from soil without straw amendment, and this reduced to 59.7% for soil amended by the straw. Soil amendment reduced surface runoff and sediment loss only when the rainfall intensity was low; when the rainfall intensity exceeded a threshold, soil amendment enhanced rather than reduced sediment runoff. Nitrogen concentration in the runoff was higher in soil without amendment than with amendment. 【Conclusion】 Amending soil with straw impacted surface runoff and loss of both sediment and nitrogen, but the effect varied with rainfall intensity. For soil without amendment, the nitrogen concentration in the runoff peaked when the rainfall intensity was 1.0 mm/min, and amending the soil with straw increased this to 1.5 mm/min.

The coastal plains of Tamil Nadu, India, are prone to floods, the most common disaster experienced in this region almost every year. This research aims to identify flood risks in the coastal plain region of Tamil Nadu, delineated through a watershed approach with 5020 micro-administrative units covering an area of about 26,000 sq. km. A comprehensive flood risk assessment covering hazard, vulnerability, and exposure parameters was carried out using multiple datasets derived from field surveys, satellite data, and secondary data sources. The flood hazard layer was prepared on a probability scale (0–1) with the help of Sentinel-1 Synthetic Aperture Radar data coupled with GIS-based water rise modelling using Shuttle Radar Topography Mission Digital Elevation Model (SRTM-DEM) and reports of the District Disaster Management Plans of 13 coastal districts. In addition, the National Resources Conservation Service-Curve Number (NRCS-CN) method was adopted to estimate surface runoff potential for identifying low probability flood-prone regions. The vulnerability and exposure of the population to flood hazards were determined using census and household data-based indicators. The different categories of built-up areas were delineated and intersected with the flood hazard layer to estimate elements at flood risk. An exhaustive field survey was conducted at 514 locations of the study area, targeting deprived communities of all major settlements to validate the flood hazard layer and understand the public perceptions. The amalgamation of results shows that very high flood risk prevails in the northern parts of coastal Tamil Nadu, especially the stretch between Chennai and Cuddalore. In addition, to provide baseline datasets for the first time at micro-administrative units for the entire coastal plains of Tamil Nadu, the study offers a pragmatic methodology for determining location-specific flood risks for policy interventions.

In Indonesia, flooding is one of the natural hazards that often occurs during the rainy season. Surface runoff coefficient values are an essential indicator of the supply of regional water resources. The smaller the surface runoff value, the greater the water storage in the ground, and the smaller surface was running water. This study analyses the spatial and temporal distribution of the estimated surface runoff caused by land use/land cover changes in the upstream Citarum watershed. The study area is located in the upstream Citarum watershed, West Java, Indonesia. The site has a long history of flooding and various complex environmental problems. The geographic Information System method was used as a tool in analyzing the spatially and temporally. The research result shows that there has been a change in land cover in several periods of the year in the Citarum upstream watershed. The occurrence of the LULC phenomenon positively affects the surface runoff coefficient. The increasing area of Built land and plantation in the Citarum upstream watershed will further increase the surface runoff coefficient and, in the end, will potentially increase the surface runoff and contribute to flooding in the Bandung basin. This study results can be used to provide input in determining the direction and policies for watershed management, taking into account the varying characteristics of each subwatershed.

The loss of N in farmland is an important cause of agricultural non-point source pollution, which seriously impacts the aquatic environment. A two-year (2017–2018) experiment was conducted to investigate the characteristics of runoff and N losses under different tillage practices. Taking downslope ridge planting and cross ridge planting as the experimental treatments, the characteristics of surface runoff, interflow, and N losses in sloping farmlands with yellow soil were studied throughout the maize growth period. As the rainfall increased, the surface runoff and interflow also increased. The surface runoff and N losses in the surface runoff of downslope ridge planting were significantly higher than those of cross ridge planting. The interflow volumes and N losses in the 0–20 and 20–40 cm soil layers of the cross ridge planting were significantly higher than those of the downslope ridge planting. The total N (TN) losses from surface runoff accounted for 54.95–81.25% of the N losses from all pathways. Therefore, we inferred that surface runoff is the main pathway of N losses. Dissolved total N (DTN) was the main form of N loss under different tillage measures, as it accounted for 55.82–94.41% of the TN losses, and dissolved organic N accounted for 52.81–87.06% of the DTN losses. Thus, we inferred that dissolved N is the main form of N loss. Future research must focus on the prevention and control of the N losses during the maize seedling stage to reduce the environmental pollution caused by ammonium N through runoff.

One part of the hydrologic cycle which has a major influence in increasing the amount of river flow discharge is surface runoff. The higher surface runoff discharge, causing the possibility of surface flooding, therefore required an empirical model that can calculate the amount of surface runoff so as to produce updated data and quickly change according to their needs. One of the empirical methods that can be used to calculate the amount of surface runoff is by using the curve number method. This research is done by utilizing remote sensing image, that is, ALOS AVNIR-2. Data extraction from ALOS imagery includes land cover information using multispectral classification analysis, slope inclination information through visual interpretation, and land use interpretation. The runoff that occurred in Banjarnegara Regency tends to be high, that is, 61.24 percent of the total area of the research area. Large runoff with very high/extreme class spread on the form of hilly land to the old volcano complex at the study site. The runoff in the medium to low class only covers 3.56 percent of the total area and is distributed on the fluvial form with the flat-to-flat slopes. The result of analysis of runoff data is obtained from slope analysis and type of land use in the research location. Increasingly steep slope with little vegetation-land use, then the greater the runoff that occurs. Finally, the research result could be implemented into higher student class activity, especially in remote sensing classes, GIS, cloud computing, and big data analysis. By this process, the students will be improved their skills in analyzing imagery data as well as create new information derived from the remote sensing data.

This paper describes the application of the storm water management model (SWMM) for predicting the sewage quality in the sanitary sewer system of the study area resulting from the leaking of stormwater surface runoff to the system during rainfall events at different return periods. The concentrations of major pollutants were assessed in the sanitary sewer system at different rainfall intensities. Then, a solution to mitigate the problem was proposed using low impact development (LID) technology. The results of sensitivity analysis indicated that maximum build-up possible was the most sensitive parameter for model calibration. The model was calibrated using actual rainfall events, and statistical validation coefficients of R (0.81–0.82) and NMSE (0.0173–0.022) proved that the model is valid. The sewage quality assessment results showed that pollutants concentration increased to its maximum level at 20 min and gradually decreased to a slightly constant minimum value after 2 h. The proposed solution of LID reduced the pollutants concentrations by 82–88, 75–77, 52–55, and 7–10% for all pollutants at return periods of 2, 5, 10, and 25 years, respectively. To conclude, SWMM simulation successfully predicted the concentration of the pollutants, and leaking of stormwater surface runoff has changed the sewage quality. HIGHLIGHTS Storm water management model (SWMM) simulated the leaking of stormwater surface runoff into the sanitary sewer system.; Sewage quality in the sewer system highly influenced by stormwater surface runoff leaking.; Low impact development (LID) strategies have been applied to mitigate stormwater surface runoff leaking.; An important information on stormwater and sewage management for decision makers, sanitary experts, and stockholders has been provided.;

The separation of surface runoff and base flow is a very specific problem in water balance calculations, particularly if there is not enough measured flow data. In this study, the SCS-CN method is used to estimate the surface runoff in the ungauged Izmit Basin. The CNs are estimated using the Hydrologic Soil Groups map, based on soil data of the General Directorate of Rural Services of Turkey and land use obtained from the CORINE-2006 database for different AMCs. The surface runoff was computed using the SCS-CN method for the ungauged Izmit Basin that corresponds to 17% and 21% of the rainfall, i.e. 134 mm (for Kocaeli Meteorological Station; rainfall=804 mm) and 171 mm (for Sakarya Meteorological Station; rainfall=820 mm). According to SCS-CN method estimates, approximately 41-42% of the annual rainfall in the Izmit Basin directly contributes to the total streamflow, and 21-25% of it contributes to base flow and unmeasured infiltration. To compare the results of the SCS-CN method along hydrograph separation method, the gauged Yuvacık Dam Sub-Basin, which is hydro-meteorologically similar to the Izmit Basin, was selected. The results showed that 16% of the rainfall in the Yuvacık Dam Sub-Basin became surface runoff. Also, it was found that about 42% of the annual rainfall in the Yuvacık Dam Sub-Basin directly contributes to the total streamflow and 23% of it contributes to the base flow and unmeasured infiltration. These results confirm that the ratio of surface runoff obtained by the hydrograph separation method in the Yuvacık Dam Sub-Basin matches with the ratio of surface runoff calculated using the SCS-CN method for the entire Izmit Basin.

In terms of land use and climate, the world is changing at an unprecedented rate and these changes have a significant influence on our water resources. This study was conducted to examine the individual and combined potential impacts of land use and climate change on the water balance of the Baro basin in Ethiopia for the baseline period (1985–2002) and near-future period (2023–2040) using the Soil and Water Assessment Tool (SWAT). The plausible land use scenarios considering current (CUR), business as usual (BAU), and further expansion of altitudinal forest and watershed management practices (CON), as well as climate change scenarios from regional climate model outputs (RCMs) under two representative concentration pathways (RCP4.5 and RCP8.5) for the 2023–2040 time frame, were used as inputs to the models. The monthly calibrated and validated SWAT model produced an acceptable result, which was then used for water balance simulations. Findings show that forest decreased from 54.5% to 48.9% and 41.2% while agricultural land increased from 21.8% to 29.7% and 39.8% under the CUR and BAU land use change scenarios, respectively. The results from the ensemble mean showed an increase in maximum and minimum temperatures and a decrease in rainfall under the RCP4.5 and RCP8.5 climate change scenarios, which in turn resulted in an increase in evapotranspiration (ET) and a decrease in water availability. Climate change outweighed the impact of land-use change, thus indicating an increase in annual ET by up to 12% and a decrease of 42% in surface runoff (SURQ) under the RCP8.5 scenario. The BAU land use scenario projection triggers a respective increase of 18% in annual SURQ and reduction of ET by 2%. However, under the CON land use scenario, SURQ decreased by 24%. The study concluded that future land use and climate change will further challenge the basin's water supply capacity to meet the increased water demand. Understanding the changes in the basin's water balance is critical for mitigation and adaptation options. As a result, this study proposes restoration efforts and climate-resilient water management strategies that can increase the resilience of the river basin.

Soil erosion is an inevitable geomorphic process that aids in evaluating and analyzing the erosive and hydrological status of the watershed. The present investigation focuses on the qualitative evaluation of the hydrologic and erosive status of eighteen watersheds (area > 10 km² ) of south Andaman using drainage morphometric studies. The objective of the present study was addressed with the aid of GIS and remote techniques. The results suggest that four watersheds such as Burmanallah, Carbyn, Burataga, and Dhania showed low levels of soil erosion. Whereas, seven watersheds via., Putatang, Colinpur, Jirkatang I, Dhanikhari, Jarawa I, Jarawa III, and Tirur exhibited high levels of soil erosion. The rest of the seven watersheds via., Bhagoda, Bilap, Bill, Jirkatang II, Jarawa II, Jarawa IV, and Mannarghat were prone to moderate levels of soil erosion. Further, the findings from forty years’ time series climate-water balance modelling reaffirm that more than 60% of rainfall divulges into the adjacent seas as surface runoff. Thus, the copious amount of fresh water and loads of nutrient-rich fluvial influx at the shallow depths of coastal frontiers aid the mangrove to respond. [ABSTRACT FROM AUTHOR]

World is facing acute water scarcity owing to growing freshwater demand, rainfall aberrations and miserable management of water resources. Selection of site for water harvesting structure is crucial for water management in basin. SWAT and AHP techniques applied for decision making at HRU level. AHP technique was used for delineation of sites using soil type, slope, runoff ratio and land use land cover criteria. Model R2 ranged from 0.85 to 0.92, NSE ranged from 0.85 to 0.92, RSR ranged from 0.28 to 0.38 and PBIAS ranged from -14.68 to 0.79 for calibration while R² ranged from 0.68 to 0.80, NSE ranged from 0.70 to 0.81, RSR ranged from 0.30 to 0.40 and PBIAS ranged from -12.7 to 0.57 for validation. upper region of basin has the highest potential of water harvesting, which can be managed efficiently by specific water harvesting structure. The tools and techniques can be adopted worldwide, for water resource planning at HRU level. [ABSTRACT FROM AUTHOR]

Wildfire can induce an increase in infiltration excess overland flow, which varies from barely detectible to extreme. Soil properties are an important contributor to this variability. Several studies found that a landscape's aridity (the balance of energy and water) is strongly correlated with an increased quantity of post‐wildfire overland flow, with burnt forests of higher aridity producing higher peak flow compared to wetter forests. Related process‐based studies suggested that this relationship can be explained by an interaction between inherent soil macroporosity (varies inversely with aridity) and fire induced water repellency; soils of higher macro‐porosity maintain high infiltration rates despite fire‐enhanced water repellence. Although the observed post‐wildfire runoff/aridity relationship has proven useful in mapping hydrological risk, its transferability is potentially limited for areas where other soil formation factors have greater influence. Here we propose that measurements related to landscape productivity may provide a mappable landscape metric that is based on soil formation processes that influence post‐fire infiltration capacity and may provide a more robust and transferable proxy of fire induced hydrologic change. To test this hypothesis, post‐wildfire runoff data from three new experimental sites with a coastal climate influence were combined with previously published data collected inland across a gradient of aridity. The results showed that post‐wildfire runoff was better correlated with measures of productivity than with aridity, supporting the hypothesis. It is therefore proposed that long‐term average productivity may be a more robust and transferable proxy in estimating the magnitude of increase in overland flow after fire than aridity. This most likely results from a stronger causal link between productivity and soil macroporosity, though this was not measured in this study. As with aridity, this proxy is mappable at high resolution using climate and remotely sensed data, enabling the application of landscape productivity metrics when predicting post‐wildfire hydrologic risk. [ABSTRACT FROM AUTHOR]

Conceptual hydrological models can move towards process‐oriented modelling when addressing broader issues than discharge modelling alone. For instance, water quality modelling generally requires understanding of both pathways and travel times which might not be easily identified because observations at the outlet aggregate all processes at the catchment scale. In this study we tested if adding a second kind of observation, specifically sediment data, can help distinguish overland flow from total discharge. We applied a multi‐objective calibration on both discharge and suspended sediment concentration simulation performance to the World‐Wide Hydrological Predictions for the Environment (HYPE) model for 111 catchments spread over the USA. Results show that in comparison to two calibrations made one after the other, the multi‐objective calibration leads to a significant improvement on the simulation performance of suspended sediments without a significant impact on the performance of discharge. New modelling hypotheses for overland flow calculations are proposed and resulted in similar discharge performances as the original one but with fewer parameters, which reduces equifinality and can prevent unwarranted model complexity in data‐poor areas. [ABSTRACT FROM AUTHOR]

During land unsoldering in Ukraine, so-called "self-seeded forests" appeared on lands that had not been used for agriculture for a long time. The purpose of the research is to find out the erosion control properties of self-seeded forests. Twelve locations of natural regeneration of various types of woody plants on the ravine-gully system of Cherkasy region were chosen as research sites. Self-seeded woods have a structure of different ages from 8 to 25 years. Most of them are represented by mixed stands, which increase their biological stability. They are better adapted to the current climate change. The formation of uneven-aged stands of natural regeneration with high resistance and erosion control properties was noted. According to the qualitative indicator of productivity, the natural regeneration turned out to be different, which was primarily caused by forest sites conditions, in particular, the steepness, the position on the slope, and the thickness of the humus horizon of the soil. The hardness of the soil was determined in the range from 17.1 to 19.0 kg/cm2, which corresponds to an average loose state. The hardness of the soil in the control was 23.9 kg/cm2, which corresponds to its compacted state. The water permeability of the soil under the studied stands was 11.1–27.3 (control – 8.9) mm/min, which characterizes it from the best to chasm. The obtained soil water permeability data confirm the rapid transfer of surface runoff to subsoil, which prevents the development of erosion processes. Natural regeneration on the slopes of the ravine-gully system is determined to be successful, although it requires considerable time for the formation of full-fledged plantations. [ABSTRACT FROM AUTHOR]

Urbanization has had a major impact on runoff process, which is not fully understood. In this study, a plot‐scale rainfall‐runoff simulation experiment was conducted in an experimental field to evaluate the effects of imperviousness and its connectivity on surface runoff. A total of 11 underlying surface scenarios with different impervious area and two imperviousness connectivity conditions were designed. For each scenario, two rainfall intensities and two initial soil moistures were applied. The results show that the relationship between the surface runoff coefficient and the impervious area under fixed imperviousness connectivity, rainfall intensity, and initial soil moisture represents a strong linear trend. With high antecedent soil moisture, imperviousness arranging in disconnected pattern can lead to initially lower but later higher outflow rate compared to imperviousness arranging in connected pattern. The sensitivity of the runoff coefficient to impervious area, which represents increased runoff coefficient per unit impervious area, is negatively related to the rainfall intensity as well as the initial soil moisture but positively related to the imperviousness connectivity. These results indicate that the impacts of the impervious surface on runoff are not only related to its connectivity, but also the original soil condition before sealing: the higher infiltration capacity of the original soil, the greater hydrological impacts caused by soil sealing. [ABSTRACT FROM AUTHOR]

Background: Pelosols are the Soil of the Year 2022 in Germany, Austria and Switzerland. They represent soils with a high clay content (≥45%) in the diagnostic P horizon. Pelosols are nutrient‐rich, have a strong capacity for swelling and shrinking, have a challenging water balance with a high portion of nonplant available water and are affected by high traction. Such special characteristics make them challenging soils under agricultural management. Aims: The occurrence, land use management and soil erosion risk of Pelosols in Germany were investigated and compared to their clay‐rich soil counterparts on a global scale. Methods: We intersected soil maps of the German and international digital soil mapping with soil erosion data. Results: A high percentage (63%) of Pelosols in Germany are under agricultural use, from which two‐thirds are arable farming. Simultaneously, Pelosols have a high risk for soil erosion by water and are the fourth most endangered soil type compared to all soil types in Germany. The average soil erosion loss of Pelosols used for agricultural practices assessed by the Revised Universal Soil Loss Equation (RUSLE) is 2.24 t ha−1 year−1 compared to an average erosion loss of all agriculturally used soils in Germany of 1.65 t ha−1 year−1. From an international perspective, Pelosols in Germany are mostly mapped as haplic Cambisols or haplic Luvisols, as they do not necessarily meet the diagnostic properties of the clay‐rich Vertisol soil type. Most Vertisols are classified as Pelosols, but Pelosols do not necessarily fulfil the diagnostic criteria of Vertisols. Vertisols on a global scale have an even higher soil erosion risk than Pelosols in Germany (3.5 t ha−1 year−1). Conclusions: Pelosols and Vertisols, despite their high percentages for agricultural use, have a high soil erosion risk compared to other soil types and thus need special care under agricultural use and adapted protective land use management. [ABSTRACT FROM AUTHOR]

Copyright of China Rural Water & Hydropower is the property of China Rural Water & Hydropower 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.)

Soil erosion varies in space and time. As the contributing surface area increases, heterogeneity effects are amplified, inducing scale effects. In the present study, soil erosion processes as affected by the observation scale and the soil surface conditions are assessed. An experimental field scale setup of 18 plots (1–150 m2) with different soil surface conditions (bare and degraded, cultivated) and slopes (0.75–4.2%) are used to monitor soil losses between 2010 to 2018 under natural rainfall. The results showed that soil loss rates range between 2.5 and 19.5 t.ha−1 under cultivated plots and increase to 12–45 t.ha−1 on bare and degraded soils, which outlines the control of soil surface conditions on soil erosion. At a larger scale (38 km2), soil losses are estimated at 2.2–4.5 t.ha−1, highlighting the major contribution of scale. The scale effect is likely caused by the redistribution of sediments in the drainage network. These findings outline the nature and contribution of the emerging and dominant soil erosion processes at larger scales. At the plot scale, however, diffuse erosion remains dominant, since surface runoff is laminar and sediment transport capacity is limited, resulting in lower soil erosion rates. [ABSTRACT FROM AUTHOR]

Snowmelt nutrient loss is an important but poorly understood process in cold climates. We measured nutrient losses at three sites after dairy manure was applied on top of an established snowpack. Treatments included no manure controls and three manure solids levels (12–19.4% solids = High; 7.5–8.0% = Medium; 2.9–5.5% = Low) applied at 26,670 L ha−1 to all treatments. Snowmelt runoff was monitored and analyzed for dissolved reactive P (DRP), total P (TP), total N (TN), ammonium-N, organic-N, and total solids (TS) concentrations. Results showed that manure application dramatically increased N and P loading compared to controls. Across site-years, manure application increased average runoff TP, DRP, and TN concentrations by 1.3- to 13.3-fold, 1.5- to 21-fold, and 1.4- to 14.2-fold, respectively, relative to controls. While cumulative N, P, and TS losses generally increased with manure solids, Medium/Low showed equal or greater nutrient transfer to runoff for some events. TN and TP lost in runoff were linearly related to manure solids concentration; however, N and P loss as a percent of applied showed the opposite trend. The results indicate that applying manure on top of snow resulted in high nutrient losses when runoff occurred regardless of manure solids content. [ABSTRACT FROM AUTHOR]

The River Basin Management Plans and relevant Integrated Water Management of the transboundary river Mesta-Nestos between Bulgaria and Greece require sufficiently complete information about the water resources in the watershed and natural risk of expected climate change. The present study aims to present the surface runoff modulus (specific discharge as a characteristic of water resources) in the watershed based on measurements from 3 hydrometric stations on Bulgarian territory for the period 1935 - 2019 and 2 on Greek territory for the hydrological years 1965-1966 to 1989-1990. An attempt has been made for assessment of Climate Change impact on the Mesta-Nestos river runoff for years 2025, 2050 and 2100 based on two different scenarios HadCM2 and ECHM4. The results show an decrease in yearly specific discharge, both in the near future and in the longer time horizon compared to the reference period 1961-1990. [ABSTRACT FROM AUTHOR]

Iodine loss is common in the soil of hilly regions due to higher precipitation rates and steeper slopes. Iodine deficiency in soil reduces iodine's bioavailability to fruits and vegetables and consequently may contribute to health complications. However, the iodine retention of soils after the addition of selected organic and inorganic amendments has not been studied. Therefore, a study was carried out to investigate iodine loss during surface runoff. For this purpose, a soil amendment (namely, sawdust, charcoal, wood ash, lime or gypsum) was applied separately to pasture and agricultural soils under natural rainfall conditions. The soil was fertigated with iodine in the form of potassium iodide (KI) at the rate of 200 ppm. Surface runoff was related to soil properties. Results showed that iodine content in surface runoff was linearly related with soil pH (R2 = 0.89, p < 0.05) and inversely related with soil organic carbon (R2 = −0.76, p < 0.05). Soils amended with sawdust had significantly reduced iodine content in runoff. A higher amount of iodine was lost via surface runoff from soil after inorganic amendment. Soil amendments were varied for iodine retention in soil in the order of sawdust > charcoal > wood ash > lime > gypsum. The study results indicated that organic amendments, especially sawdust, improved soil properties and increased the iodine retention capacity of soils. [ABSTRACT FROM AUTHOR]

Given the rapid pace of urbanization and resulting pressures on water supplies in many regions, landscape water conservation has become increasingly important for many communities. To achieve this goal, programs incentivizing partial or complete removal of turfgrass lawns have been developed by many municipalities. While prior studies have been published examining effects of urban land change on stormwater runoff, few have addressed how the transition from traditional home lawns to alternative water-efficient landscapes alters runoff water quality. The objective of this 13-month study was to compare differences in stormwater runoff quality attributes among five commonly used urban residential mesocosms including established St. Augustinegrass lawn and four alternative residential mesocosms including xeriscaping, mulch, artificial turf, and sand-capped lawn. Runoff quality parameters including pH, electrical conductivity, nitrate–N, ammonium-N, dissolved organic N, total dissolved N, orthophosphate-P, total suspended solids, and dissolved organic carbon were monitored. Results demonstrated that export of nutrients via runoff, specifically N and P, were influenced by mesocosm type. In particular, artificial turf showed elevated runoff nitrate–N relative to other mesocosms, possibly due to minimal plant absorption of inorganic N coming onto plots as dry and wet deposition. However, an additional layer of compacted decomposed granite used for xeriscapes and artificial turf seems to have protected legacy soil P from leaving the system as runoff. Collectively, the findings of this study demonstrate that there is no one specific landscape that is best suited for mitigating runoff quality, but rather, alternative mesocosms should be selected based on local climate and environmental concerns. [ABSTRACT FROM AUTHOR]

Watershed-scale hydrology and soil erosion are the main environmental components that are greatly affected by environmental perturbations such as climate and land use and land cover (LULC) changes. The purpose of this study is to assess the impacts of scenario-based LULC change and climate change on hydrology and sediment at the watershed scale in Rib watershed, Ethiopia, using the empirical land-use change model, dynamic conversion of land use and its effects (Dyna-CLUE), and soil and water assessment tool (SWAT). Regional climate model (RCM) with Special Report on Emission Scenarios (SRES) and Representative Concentration Pathway (RCP) outputs were bias-corrected and future climate from 2025 to 2099 was analyzed to assess climate changes. Analysis of the LULC change indicated that there has been a high increase in cultivated land at the expense of mixed forest and shrublands and a low and gradual increase in plantation and urban lands in the historical periods (1984–2016) and in the predictions (2016–2049). In general, the predicted climate change indicated that there will be a decrease in precipitation in all of the SRES and RCP scenarios except in the Bega (dry) season and an increase in temperature in all of the scenarios. The impact analysis indicated that there might be an increase in runoff, evapotranspiration (ET), sediment yield, and a decrease in lateral flow, groundwater flow, and water yield. The changing climate and LULC result in an increase in soil erosion and changes in surface and groundwater flow, which might have an impact on reducing crop yield, the main source of livelihood in the area. Therefore, short- and long-term watershed-scale resource management activities have to be designed and implemented to minimize erosion and increase groundwater recharge. [ABSTRACT FROM AUTHOR]

Land use and cover change are closely linked to catchment hydrology characteristics. Land uses and cover determine the ability of the catchment to collect, store, and release water. The catchment water storage and flow ability affect the quantity and timing of runoff, soil erosion, and sediment transport downstream. Agriculture on of the major drivers for the changes in water flow pathways, which also causes a catastrophic shift of aquatic ecosystems. We assessed the impact of land-use changes on the water flow characteristics in the Upper Pangani Sub catchment using the hydrologic model Soil and Water Assessment Tool (SWAT). Land use and cover changes within the Upper Pangani Sub catchment were analyzed between 1987 and 2017 using QGIS. The result shows that agriculture has expanded from 96,737 ha to 314,871 ha between 1987 and 2017. Bare land and built-up land have gained 14690 ha and 7083 ha respectively during this period. Land-use changes have affected the basin's land cover. Forest has decreased from 196558 ha to 106839 ha between 1987 and 2017. Bush land cover has lost 83445 ha during this period. Bushland cover fall victim to agricultural activities, whereas forest is cleared for logging and fire incidences. Consequently, surface runoff has increased from 60.84 to 73.02 (20.6% increase) between 1987 and 2017. Sediment yield has increase from 6.9 to 12.74 ton/ha (46% increase), and groundwater recharge has decreased from 106.53 to 99.56 (6.5% decrease). It concluded that land cover transformation alters hydrology characteristics of the catchment, resulting to fast surface flow, high rate of soil erosion and low infiltration rate. It is recommended that agro-forestry should be emphasized in the catchment. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board 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.)

The dynamics of fluvial erosion responds to soil erosion and surface runoff on hillslopes due to land use and environmental fragility, conditioned by the soil, geology, relief, and rainfall rate. Despite the increasing problems associated with fluvial erosion in Brazil, little information is available on bedload transport in headwater catchments under intense agricultural activity. Therefore, this study sought to characterize the fluvial erosion processes and bedload dynamics in an experimental catchment in southern Brazil located at the edge of the Brazilian Meridional plateau, which is representative of a large area of high environmental fragility and intense agricultural activity in Southern Brazil. The Guarda Mor River drains a headwater catchment (18.5 km 2 ) with undulating and hilly terrain with fragile soils and intense agricultural activity controlling fine and coarse sediment supply downstream. During 11 major rainfall-runoff events, monitoring was conducted to measure streamflow, bedload transport rates, sediment size, and hydraulic parameters, such as Manning's n values and viscous layer thicknesses. A rating curve was established based on 40 streamflow and bedload discharge measurements taken at different water levels and stages along the hydrograph. In addition, a river portion (gravel bed) was characterized as well as the granulometric characteristics of its surface and subsurface layers. The results showed that the transport pattern is influenced by factors other than hydraulic parameters alone, including the interdependence between successive events, armoring effects, and hysteresis. These factors are strongly related to the surface runoff and erosion observed on the hillslopes, which define the streamflow energy and the supply of sand fraction, respectively. A discussion is held on the bedload transport dynamics under non-equilibrium conditions in the modeling of fluvial erosion processes., Competing Interests: Declarations. Ethical approval: Not applicable., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)