Application Of SWAT Research Articles

Modeling soil erosion susceptibility considering morphometric analysis and SWAT application: policy recommendation to achieve SDGs

Modeling soil erosion susceptibility considering morphometric analysis and SWAT application: policy recommendation to achieve SDGs

Application of SWAT and WEAP Models for Sustainable Management of Water Resources in the Two Rivers Dam Catchment, Uasin Gishu County, Kenya

Kaptagat Forest, the main source of the Ellegerini River, which feeds the Ellegerini Dam and Two Rivers Dam, is under threat of extinction due to human activity. The Two Rivers Dam catchment that has over the years been a source of water in Uasin Gishu County is slowly depleting and urgent measures are required to restore it. Activities including commercial logging, charcoal burning and firewood harvesting have exerted a lot of pressure on the catchment, posing a great threat to the livelihoods of the people of Eldoret town who depend on the reservoirs for water supply. The main objective of this study was to customise SWAT and WEAP models for the sustainable management of water resources in the Two Rivers Dam catchment. The specific objectives were to set up and apply the SWAT model to generate simulated river flows draining to the Two Rivers and Ellegerini Reservoirs as an input to the WEAP model to determine the impact of land use change on the hydrological function of the Two Rivers Dam catchment, to set up, calibrate and validate a WEAP model for the Two Rivers Dam catchment and to apply the WEAP model in analyses of various management and infrastructural development projects scenarios to enhance river flow and water storage in the Two Rivers and Ellegerini Reservoirs. The goodness of fit SWAT model statistical evaluation indices attained during the calibration period was R2 = 0.854, NSE = 0.822 and Bias = 0.392. Additionally, for the validation period, the R2 = 0.786, NSE = 0.815 and Bias = 0.381. The modelled results indicate that the land use change resulted in decreased baseflow and increased surface runoff hence the high fluctuations of water levels in the Two Rivers and Ellegerini reservoirs. The WEAP model results for actual and simulated water demand in the calibration period of 2019, the R2 = 0.88, while during the validation period in the year 2020, the R2 = 0.85. The results of the model simulation indicated that the management option that had the most impact on all the scenarios was the reduction of unaccounted-for water, while the one with the least impact was increased water use efficiency. It was concluded that the models were able to simulate the observed conditions reasonably well and can therefore be used to effectively manage water resources and assist the relevant stakeholders in decision-making. The study recommended that forested areas need to be properly conserved in order to restore the hydrological function of the catchment.

Application of SWAT and MODFLOW models for characterization of surface–groundwater interaction in the Modjo River catchment, central Ethiopia

Application of SWAT and MODFLOW models for characterization of surface–groundwater interaction in the Modjo River catchment, central Ethiopia

Erosion and sedimentation analysis as basic reference for land conservation planning on lesti Sub-watershed

The Lesti sub-watershed area is mostly steep mountain slopes, when the rain fall it carries erosion and sediment material. This study aims to discover the trend of land-use changes; measure the amount of erosion rate and Erosion Hazard Levels; obtain the sediment-transport actual quantity based on SWAT application; discover the scatter of land critical-level; and determine the strategy for implementing conservation and controlling the erosion rates. Erosion Hazard Level were obtained as follows: Class I 11.92%; Class II 27.45%; Class III 43.85%; Class IV 13.06%; Class V 3.99%. Four (4) parameters overlaid to determine the land criticality level are: land coverage, land slope, erosion risk level, and management aspect. Generally, Lesti Sub-Watershed is categorized as: very critical 0.14%; critical 4.61%; a rather critical 28.06%; critical potential 53.66%; and normal 13.51%. From SWAT analysis the average value respectively soil erosion is 119.60 tons/ha/year; sediment yields 310.77 tons/ha/year; rainfall 2143.27 mm/year; and surface runoff 1120.65 mm/year. The suggestions of the watershed area conservancy requires a vegetative (planting) and mechanical (building) method. The vegetative method such as: alleys cropping; reforestation; agroforestry; relay cropping; soil cover cropping as natural green manure; living fence; mixed cropping farm; mulch; environment greening; strip cropping with 20.65% effectivity; and filter strip with 26.03% effectivity. The mechanical method such as: contour tillage with 29.71% effectivity; terracing with 23.41% effectivity; check dam with 17.50% effectivity; and mound.

The application of SWAT+ model to quantify the impacts of sensitive LULC changes on water balance in Guder catchment, Oromia, Ethiopia

Global population growth and scarce resources increase the competition for land use. Despite the fact that the impacts of climate change have been recognized, the conversion of LULC is still often neglected and threatens catchment hydrology. This is mostly seen in the developing world, where agriculture is the crucial source of their food security. The conversion of LULC has been jeopardizing water balance components and damaging ecosystem. This study demonstrates the application of SWAT+ in quantifying the impacts of LULC changes on the Guder catchment water balance. The impacts were quantified between 2003 and 2021, and the watershed experienced an increase in agriculture and settlement while forest, shrubland, and wetlands declined. The time-series-based performance of the SWAT + model shows the model is more restructured and capable of simulating streamflow compared to observed during calibration and validation. In this long-term evaluation, the model simulates changes in runoff of 56.5%, water yield of 65.2%, lateral flow of 21.6%, percolation of 46.2%, return flow of 76.4%, and ET of 0.2% between 2003 and 2013. Moreover, some attributes of the water balance have increased from 2013 to 2021, with runoff of 34.3%, water yield of 2.3%, ET of 4.5%, and lateral flow of 72.6%. However, as a result of increasing settlement, which reduces infiltration through interceptions and converts rainfall to runoff, percolation and return flow were decreased by 45.6% and 86.7%, respectively. Water yield and runoff show a linear relationship with changes in LULC, and the most sensitive land use changes that affect them are agriculture, forest, and settlements. The simulation results show a water balance deficit under the impacts of LULC changes in the third simulation. Furthermore, the increased surface of runoff has been limiting the amount of groundwater recharge into the soil and reducing return flow and percolation in the second simulation.

Application of SWAT, Random Forest and artificial neural network models for sediment yield estimation and prediction of gully erosion susceptible zones: study on Mayurakshi River Basin of Eastern India

The study aims to estimate annual sediment yields of Mayurakshi River Basin using SWAT tool of ArcGIS. Climatic aspects, soil, land use and slope maps were integrated within SWAT tool to predict sediment yield capacity using MUSLE method. Alongside, the study attempts to identify spatial distribution of major gully erosion prone sites using ANN and RF models. Twelve Gully Erosion Conditioning Factors namely, elevation, curvature, aspect, runoff, TWI, slope, geology, stream frequency, rainfall erosivity, NDVI, LS-factor and LULC were selected. A gully erosion inventory map was prepared using 128 gully sites and divided into training (70%) and testing (30%) classes. Results obtained from the study shows that sediment yield capacity is very high in north-western and south-western parts of the basin due to high probability of gully erosion. Both ANN (ROC 0.96, Kappa 0.92) and RF (ROC 0.97, Kappa 0.94) models have high prediction accuracy and strong interrater reliability with MUSLE (0.60 and 0.75).

Application of SWAT Using Snow Data and Detecting Climate Change Impacts in the Mountainous Eastern Regions of Turkey

In recent years, the potential impacts of climate change on water resources and the hydrologic cycle have gained importance especially for snow-dominated mountainous basins. Within this scope, the Euphrates-Tigris Basin, a snow-fed transboundary river with several large dams, was selected to investigate the effects of changing climate on seasonal snow and runoff. In this study, two headwater basins of the Euphrates River, ranging in elevation between 1500–3500 m, were assigned and SWAT was employed as a hydrological modeling tool. Model calibration and validation were conducted in a stepwise manner for snow and runoff consecutively. For the snow routine, model parameters were adjusted using MODIS daily snow-covered area, achieving hit rates of more than 95% between MODIS and SWAT. Other model parameters were calibrated successively and later validated according to daily runoff, reaching a Nash-Sutcliffe efficiency of 0.64–0.82 in both basins. After the modeling stage, the focus was drawn to the impacts of climate change under two different climate scenarios (RCP4.5 and RCP8.5) in two 30-year projection periods (2041–2070 and 2071–2099). From the results, it is estimated that on average snow water equivalent decreases in the order of 30–39% and snow-covered days shorten by 37–43 days for the two basins until 2099. In terms of runoff, a slight reduction of at most 5% on average volume is projected but more notably, runoff center-time is expected to shift 1–2 weeks earlier by the end of the century.

Land use and its effect on runoff modeled with SWAT

La importancia de los modelos de simulación para el monitoreo de los recursos naturales cada vez es mayor. El objetivo del presente estudio fue aplicar el modelo SWAT (Soil Water Assessment Tool) para evaluar el impacto del cambio de uso de suelo sobre el escurrimiento y sedimentos en la cuenca del Río Chapingo de 1999 a 2015. Se generaron dos mapas de uso de suelo mediante la fotointerpretación de imágenes Landsat y RapidEye con resoluciones de 15 y 5 m, respectivamente y recorridos de campo para verificación. Ante la falta de datos de escurrimiento confiable y reciente se utilizaron los registros mensuales de los períodos 1964-1970 y 1971-1975 para la calibración y validación del modelo. En este proceso los coeficientes de Nash-Sutcliffe fueron de 0.58 y 0.52, respectivamente. El uso de suelo de la cuenca en el período de estudio cambió: agricultura (-6.9 %) zona urbana (+2.89%), área de minería (+5.04 %) y pastizal (+7.75 %). La aplicación del SWAT calibrado y validado sólo para escurrimiento para el período 1999-2015 no detectó cambios en el escurrimiento (p = 0.2351) y sedimentos (p = 0.4430) en función del cambio de uso de suelo determinado. La correlación entre el escurrimiento y sedimentos anuales simulados con SWAT fue significativa (p = 0.0116) con un R2 bajo (0.36), atribuible a la falta de datos de campo de sedimentos para calibrar y validar el SWAT, además de la presencia de acciones de conservación de suelo y agua en la cuenca estudiada.

The application of SWAT-GIS tool to improve the recharge factor in the DRASTIC framework: Case study

The robustness of groundwater vulnerability assessment using the conventional DRASTIC framework is highly dependent on the quality of the input data. The current study investigates the vulnerability of the western part of the coastal aquifer of the Gaza Strip, part of the Palestinian southern-western coastal aquifer. The study intends to re-introduce the recharge factor (R) in DRASTIC framework through the application of SWAT model and investigates its impact on the quality of vulnerability assessment compared with the conventional DRASTIC framework (No SWAT) . Not only a higher recharge resolution map was generated when applying the SWAT model, but also an improved vulnerability index by 52% due to the incorporation of the local zonal-operation vulnerability concept was achieved. While the conventional DRASTIC framework (No SWAT) resulted in 74% of the study area has either extreme high or extreme low vulnerability classes, SWAT model was able to smoothen the vulnerability identification by capturing the slight gradual vulnerability variation over the study area with more precise vulnerability assessment. The resulted vulnerability assessment was validated using real field nitratedata(NO3-) of water samples collected from the entire study area. The vulnerability assessment using the SWAT model was in good agreement with the nitrate levels in the area compared with the conventional DRASTIC where the residual error encountered in the case of SWAT application (20%) was less than in the conventional DRASTIC;(77%) . The results were also validated using receiver operator classification (ROC) and the area under curve (AUC) confirming the improved assessment due to SWAT model application. The current new approach is sought to support the decision-making process and water managers to better manage the proposed aquifer recharge scheme in the study area as well as to better manage the limited water resources.

Studi Penentuan Nilai Koefisien Pengaliran DAS Batang Arau di Kota Padang

Batang Arau river is located 0048” up to 0056” SL (South Latitude) and on 100021” up to 100033” LE (Longitutede East), and upstream part water catcment area it is cover 30,90 km2 area. The above said catchment area is a region consist of densely .populated and also dominated by vegetation of natural forest, protected forest, people’s forest, mixed forest, farm, recefield and yard. Based on site observation, most of the forest has changed become residant farms and settlement. This condition can be shown by land use map and change of runoff which was change from year to year. With this land use change however will also affecty changing of runoff coefficient. The goals of this study is to get flow coefficient (c) based on land use coefficient, debit AWLR, and based on SWAT application. Calculation of the coefficient based on land use map until be done by Arcgis method, debit AWLR using Hasper method and SWAT application. Study shown in period between 2009 – 2017, coefficient flow result is in range 0,36 – 0,37. Flow coefficient using AWLR result is in range 0,36 – 0,37, while flow coefficient using SWAT method is 0,25 – 0,36

Application of an Integrated SWAT–MODFLOW Model to Evaluate Potential Impacts of Climate Change and Water Withdrawals on Groundwater–Surface Water Interactions in West-Central Alberta

It has become imperative that surface and groundwater resources be managed as a holistic system. This study applies a coupled groundwater–surface water (GW–SW) model, SWAT–MODFLOW, to study the hydrogeological conditions and the potential impacts of climate change and groundwater withdrawals on GW–SW interactions at a regional scale in western Canada. Model components were calibrated and validated using monthly river flow and hydraulic head data for the 1986–2007 period. Downscaled climate projections from five General Circulation Models (GCMs), under the RCP 8.5, for the 2010–2034 period, were incorporated into the calibrated model. The results demonstrated that GW–SW exchange in the upstream areas had the most pronounced fluctuation between the wet and dry months under historical conditions. While climate change was revealed to have a negligible impact in the GW–SW exchange pattern for the 2010–2034 period, the addition of pumping 21 wells at a rate of 4680 m3/d per well to support hypothetical high-volume water use by the energy sector significantly impacted the exchange pattern. The results showed that the total average discharge into the rivers was only slightly reduced from 1294 m3/d to 1174 m3/d; however, localized flowrate differences varied from under 5 m3/d to over 3000 m3/d in 320 of the 405 river cells. The combined potential impact is that intensive groundwater use may have more immediate effects on river flow than those of climate change, which has important implications for water resources management and for energy supply in the future.

Development of a hydrology and water quality model for a large transboundary river watershed to investigate the impacts of climate change – A SWAT application

The aim of this study is to assess a different approach of SWAT model setup with enhanced Hydrologic Response Unit (HRU) definition procedure. The method uses a set of customizable MATLAB scripts (hence, SWAT-LAB) to produce HRUs from a combination of topographic, soil, landuse and administrative unit rasterized datasets. We used this approach to setup, run and calibrate a large-scale transboundary Nemunas River model, consisting of eleven sub-models. Nemunas River is the major contributory that discharges into the Curonian Lagoon, which is the largest European coastal lagoon. Belarus, Lithuania, Poland and the Russian Federation Kaliningrad Oblast share Nemunas River basin area. The basin is experiencing nutrient load from different sources in the riparian countries, nevertheless, the burden of improving the water quality of the river falls mainly on Lithuania. This article focuses on assessing the practicability of SWAT-LAB for creating a high-resolution large-scale transboundary hydrological and water quality model, where data availability is limited and fragmented. We demonstrate the model performance on a case study of one of the Nemunas River tributaries: Neris or Vilija River basin, which is situated largely in the Republic of Belarus. Model performance was evaluated graphically, using hydrographs and percent exceedance curves, and quantified using coefficient of determination (R2) and Nash–Sutcliffe efficiency (NS). We achieved good model performance for monthly (calibration R2 = 0.80, NS = 0.83; validation R2 = 0.80, NS = 0.76) and daily (calibration R2 = 0.66, NS = 0.66; validation R2 = 0.67, NS = 0.66) flow. Satisfactory performance results were achieved in modeling monthly loads of suspended sediments (calibration R2 = 0.4, NS = 0.44; validation R2 = 0.58, NS = 0.34), total phosphorus (calibration R2 = 0.71, NS = 0.61; validation R2 = 0.53, NS = 0.56) and total nitrogen (calibration R2 = 0.55, NS = 0.42; validation R2 = 0.48, NS = 0.4). Furthermore, we use the model to assess possible future nutrient loads that could be transported from Belarus to Lithuania under two climate change scenarios (RCP 4.5 and 8.5) and present the results.

Evapotranspiration management based on the application of SWAT for balancing water consumption: A case study in Guantao, China

Rapid social and economic development results in increased demand for water resources. This can lead to the unsustainable development and exploitation of water resources which in turn causes significant environmental problems. Conventional water resource management approaches, such as supply and demand management strategies, frequently fail to restore regional water balance. This paper introduces the concept of water consumption balance, the balance between actual evapotranspiration (ET) and target ET, and establishes a framework to realize regional water balance. The framework consists of three stages: (1) determination of target ET and actual ET; (2) quantification of the water-saving requirements for the region; and (3) reduction of actual ET by implementing various water saving management strategies. Using this framework, a case study was conducted for Guantao County, China. The SWAT model was utilized to aid in the selection of the best water saving management strategy by comparing the ET of different irrigation methods and crop pattern adjustments. Simulation results revealed that determination of SWAT model parameters using remote sensing ET is feasible and that the model is a valuable tool for ET management. Irrigation was found to have a greater influence on the ET of winter wheat as compared to that of maize, indicating that reduction in winter wheat cultivation is the most effective way to reduce regional ET. However, the effect of water-saving irrigation methods on the reduction of ET was not obvious. This indicates that it would be difficult to achieve regional ET reduction using water-saving irrigation methods only. Furthermore, selecting the best water saving management strategy by relying solely on the amount of reduced ET was insufficient, because it ignored the impact of water conservation measures on the livelihood of the agricultural community. Incorporating these considerations with our findings, we recommend changing the current irrigation method to sprinkler irrigation and replacing 20% of the winter wheat-maize cultivated area with cotton, as the best strategy to achieve water balance in the study area.

Application of SWAT and 3D Environment in Flood Detection Senario of Terengganu Watershed

Application of SWAT and 3D Environment in Flood Detection Senario of Terengganu Watershed

Impact of Abandoned Opencast Mines on Hydrological Processes of the Olidih Watershed in Jharia Coalfield, India

The Olidih watershed hydrology was affected by opencast mines for the past five decades. This study explores the potential hydrological effect of these mines using Soil and Water Assessment Tool (SWAT2012). The calibration and validation of the model was performed using daily streamflow and sediment yield data (2005–2008) at the outlet of the water shed. The model performed satisfactorily during simulation when tested with statistical indicators. The alternative scenario of no-mines was also modelled to assess the potential impact of abandoned opencast mines for the period 2005–2010. Results show that the abandoned opencast mines play a crucial role in altering hydrological processes of the watershed with 16% increase in the annual sediment yield and reduction of 51% and 6% in annual surface flow and water yield, respectively. This may be due to surface soil disturbance and accumulation of surface runoff in large depressions that resulted in less surface runoff and 13% more groundwater flow. The contribution of this analysis is the application of SWAT in modelling potential hydrological effect of abandoned opencast mines by defining large opencast mines as pothole during simulation.

A scientometrics review on nonpoint source pollution research

The purpose of this paper is to make insights into certain characteristics of nonpoint source pollution research, and consequently to show the global trends as well as assist researchers to establish future research directions. Based on the SCI-E and SSCI databases, 3246 journal articles on nonpoint source pollution were retrieved from 2001 to 2015. Nonpoint source pollution research maintained steady growth in the past 15 years. Among all countries, USA was the most active contributor with the most publications and cooperation. As for institutions, Chinese Academy of Sciences ranked first with 143 articles, and USDA-ARS in USA played a key role for intimate collaboration with other institutions. And most articles were recorded by Environmental Sciences & Ecology, Environmental Sciences and Water Resources. Further, Journal of Environmental Quality and Water Research were the most productive and influential journals, respectively. Based on keyword co-word and reference co-citation analysis by Citespace, nonpoint source pollution research includes multiple areas (control measures, modeling, pollutants, research regions and technologies). And future researches on nonpoint source pollution will likely focus on SWAT application, GIS and ecological measures.

Using SWAT for Strategic Planning of Basin Scale Irrigation Control Policies: a Case Study from a Humid Region in Northern Germany

The eco-hydrological model SWAT is used worldwide for simulating hydrology and water quality of agricultural catchments. One of the main water uses is irrigation, predominantly in arid and semi-arid regions. Climate impact simulations show that a future increase of irrigation demand can be expected for humid regions. Options for adaptation include the improvement of irrigation techniques and the modification of crop patterns. In our study we investigate the application of SWAT for the development of water saving irrigation control strategies in a humid river catchment in Northern Germany. We developed different scenarios using both soil moisture deficit control and plant water demand control. The results show plausible changes of irrigation amounts when changing the trigger points of both control methods. By deficit control strategies, the water consumption could be reduced with only a moderate decrease of crop yield. Differences between soil characteristics were well shown in the SWAT simulations, but the model consistently overestimated irrigation values. Furthermore we found a high variability of the model errors between the different years, even if the long term average values are considered acceptable. Future research is needed to improve the model accuracy in automatic irrigation control.

Evaluation of potential evapotranspiration assessment methods for hydrological modelling with SWAT—Application in data-scarce rural Tunisia

Potential evapotranspiration (PET) is an important factor used in hydrological models as well as in management of irrigation projects and water-balance estimations. At the catchment level, hydrological models first calculate PET and then actual evapotranspiration (ET) by considering soil moisture and land use. In this study, we used the SWAT model to estimate PET, actual ET and streamflow. SWAT provides three methods for computing PET: (i) Penman-Monteith (PM), (ii) Hargreaves (HA) and (iii) Priestly-Taylor (PT). Due to missing weather parameters for the PM method, a statistical weather generator embedded in SWAT, WXGEN was used in several studies to generate missing weather data and to fill in gaps in measured records. The goals of this work were to evaluate the PM method’s accuracy in calculating PET using generated and measured meteorological data and further to compare the three embedded methods in SWAT to predict PET. The model was applied to the Joumine basin, covering an area of 418km2, located in northern Tunisia. For each run, simulated streamflow was compared with measured data by calculating Nash-Sutcliffe efficiency, root mean square error and coefficient of determination. The PM method predicted PET well with generated data. The method used to calculate PET did not considerably affect stream flow predictions; however, significant differences were found among them. Model predictions of streamflow were close to observed values, with a Nash-Sutcliffe efficiency of 0.90 and R2 value of 0.92after monthly calibration using HA method. During the validation period, SWAT predictions were nearly as accurate, with Nash-Sutcliffe efficiency and R2 values of 0.89 and 0.92, respectively.

Improved Swat Model and Application in Simulation of Snowmelt Runoff

The improved model for double layer snowpack melting was put forward to overcome the disadvantages of the DG (Degree-Day) model which had simple principle and neglected the relevant factors which could be important to the simulation of snowmelt runoff. The surface snowpack model, improved top layer snowpack model and model parameters calculation were studied. The structure and calculation method were put forward to improve double layer snowpack runoff model. Finally, taking the Lancangjiang River as an example, the snowmelt runoff was calculated by the improved SWAT model. Through comparison, it revealed that between two models that the simulation results of the improved double layer snow melting model was obviously better than that of the DG model in evapo-transpiration loss, the distinguish among cover layer, snowfall, rainfall and snowpack water equivalent calculation, and melting snowpack refrozen as well as adaption condition.

Development and application of the modelling system J2000-S for the EU-water framework directive

Abstract. The scientific sound definition of measures to achieve the goals of the EU water framework directive (WFD) acquires spatially distributed analyses of the water and substance dynamics in meso- to macro-scale catchments. For this purpose, modelling tools or systems are needed which are robust and fast enough to be applied on such scales, but which are also able to simulate the impact of changes on single fields or small areas of a specific land use in the catchment. To face these challenges, we combined the fully-distributed hydrological model J2000 with the nitrogen transport routines of the Soil Water Assessment Tool SWAT model, which are normally applied in a semi-distributive approach. With this combination, we could extend the quantitative focus of J2000 with qualitative processes and could overcome the semi-distributed limitation of SWAT. For the implementation and combination of the components, we used the Jena Adaptable Modelling System JAMS (Kralisch and Krause, 2006) which helped tremendously in the relatively rapid and easy development of the new resultant model J2000-S (J2000-Substance). The modelling system was applied in the upper Gera watershed, located in Thuringia, Germany. The catchment has an area of 844 km2 and includes three of the typical landscape forms of Thuringia. The application showed, that the new modelling system was able to reproduce the daily hydrological as well as the nitrogen dynamics with a sufficient quality. The paper will describe the results of the new model and compare them with the results obtained with the original semi-distributed application of SWAT.