Analysis of Non-Point Source Pollution Features of Chao River Basin Based on the CMADS-Driven SWAT Model

By the China Meteorological Assimilation Driving Datasets for the Soil and Water Assessment Tool (SWAT) model (CMADS 1.0), this paper simulated the non-point source (NPS) pollution of Chao River Basin in the upper reach of Miyun Reservoir, and analyzed the spatial-temporal distribution pattern of nitrogen and phosphorus pollutants and the contribution rates of pollution sources. The major findings of the research are as follows. The CMADS V1.0-driven SWAT model shows good applicability to the study area. The simulation of the runoff, nitrogen and phosphorous pollution in the calibration period and the validation period has yielded a Nash-Sutcliffe efficiency (Ens) coefficient at 0.51~0.78, and a coefficient of determination at 0.73~0.88, which meets the model evaluation standards. The total nitrogen (TN) and total phosphorus (TP) pollution load in the flood season is considerably large, and the average inflow of TN and TP into the reservoir accounts for 60.62% and 75.15% the total annual inflow, respectively. The #26 sub-basin marks the biggest TN and TP loads, and it is thus worth more attention from pollution control administrations. Overall, the TN and TP load in the lower reach of the basin are larger than the upper reach. NPS pollution is the major type of pollution caused by human production and life. The livestock and poultry farming as well as fertilizers, which are the main contributors to NPS pollution, are considered the focus of NPS pollution control.

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Evaluating the influence of hydrological condition on the phosphorus loads in an agricultural river basin using the SWAT model

Hydrology Research ◽

10.2166/nh.2021.165 ◽

2021 ◽

Author(s):

Cui Jian ◽

Yue Zhao ◽

Wenchao Sun ◽

Yan Chen ◽

Bo Wu ◽

...

Keyword(s):

River Basin ◽

Pollution Control ◽

Assessment Tool ◽

Swat Model ◽

River Basin Management ◽

Hydrological Conditions ◽

Basin Scale ◽

Phosphorus Loads ◽

Using Data ◽

And Control

Abstract Excessive phosphorus is an important cause of eutrophication. For river basin management, source identification and control of nonpoint source (NPS) pollution are difficult. In this study, to explore influences of hydrological conditions on phosphorus, the Soil and Water Assessment Tool (SWAT) model is applied to the Luanhe River basin in North China. Moreover, influences of the spatial scale of the livestock and poultry amount data on estimations of phosphorus loads are also discussed. The results show that applying town-level livestock and poultry amount data allows the model to perform better when estimating phosphorus loads, indicating that using data at a finer administrative level is necessary. For the typical wet year, the estimated annual phosphorus load was 2.6 times that in the typical dry year. Meanwhile, the contribution of pollution in summer to the annual load is greater in the wet year than that in the dry year. The spatial distributions of subbasins with high unit loads of phosphorus differ under different hydrological conditions, meaning that critical areas for pollution control vary with the wetness of each year. All these findings indicate that for pollution control at basin scale, considering the seasonal and interannual variabilities in hydrological conditions is highly demanded.

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Evaluation of best management practices for non-point source pollution based on the SWAT model in the Hanjiang River Basin, China

Water Science & Technology Water Supply ◽

10.2166/ws.2021.196 ◽

2021 ◽

Author(s):

Shu Li ◽

Jiake Li ◽

Gairui Hao ◽

Yajiao Li

Keyword(s):

Point Source ◽

River Basin ◽

Best Management Practices ◽

Management Practices ◽

Swat Model ◽

Forest Land ◽

Best Management ◽

Flood Season ◽

Nps Pollution ◽

Hanjiang River

Abstract Taking the Hanjiang River basin with Ankang hydrological station as the control section as the study area, the Soil and Water Assessment Tool (SWAT) model is used to identify the spatial and temporal distribution of non-point source (NPS) pollution and determine the critical source areas (CSA). Then we set up 11 best management practices (BMPs) in the CSA and evaluate their environmental and comprehensive benefits. The results show that TN and TP loads in flood season are significantly higher than that in non-flood season. The distribution of loss intensity of TN and TP load has a strong correlation with runoff and sediment erosion intensity, respectively. Among the 8 individual BMPs, the reduction rates of stubble coverage, grassed waterway and returning farmland to forest land are relatively high, and the comprehensive attribute value Z of stubble coverage is the highest. Among the 3 combined BMPs, the reduction rate of ‘stubble coverage + grassed waterway + returning farmland to forest land (>25°)’ is the highest and the Z value is the largest. Overall, the BMPs such as stubble coverage, grassed waterway, and returning farmland to forest land can be adopted alternately to control NPS pollution in the Hanjiang river basin.

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Assessment of the SWAT model in simulating watersheds in arid regions: Case study of the Yarmouk River Basin (Jordan)

Open Geosciences ◽

10.1515/geo-2020-0238 ◽

2021 ◽

Vol 13 (1) ◽

pp. 377-389

Author(s):

Majed Abu-Zreig ◽

Lubna Bani Hani

Keyword(s):

River Basin ◽

Assessment Tool ◽

Positive Impact ◽

Swat Model ◽

Development Project ◽

Coefficient Of Determination ◽

Statistical Measures ◽

Yarmouk River ◽

Monthly Runoff ◽

The Impact

Abstract The Soil and Water Assessment Tool (SWAT) was used to simulate monthly runoff in the Yarmouk River Basin (YRB). The objectives were to assess the performance of this model in simulating the hydrological responses in arid watersheds then utilized to study the impact of YRB agricultural development project on transport of sediments in the YRB. Nine and three years of input data, namely from 2005 to 2013, were used to calibrate the model, whereas data from 2014 to 2015 were used for model validation. Time series plots as well as statistical measures, including the coefficient of determination (R 2) and the Nash–Sutcliffe coefficient of efficiency (NSE) that range between 0 to 1 and −∞ to 1, respectively, between observed and simulated monthly runoff values were used to verify the SWAT simulation capability for the YRB. The SWAT model satisfactorily predicted mean monthly runoff values in the calibration and validation periods, as indicated by R 2 = 0.95 and NSE = 0.96 and R 2 = 0.91 and NSE = 0.63, respectively. The study confirmed the positive impact of soil conservation measures implemented in the YRB development project and confirmed that contouring can reduce soil loss from 15 to 44% during the study period. This study showed that the SWAT model was capable of simulating hydrologic components in the drylands of Jordan.

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Eco-Compensation Schemes for Controlling Agricultural Non-Point Source Pollution in Maoli Lake Watershed

Water ◽

10.3390/w13111536 ◽

2021 ◽

Vol 13 (11) ◽

pp. 1536

Author(s):

Yumei Zheng ◽

Guangchun Lei ◽

Peng Yu

Keyword(s):

Water Quality ◽

Point Source ◽

Agricultural Land ◽

Assessment Tool ◽

Evaluation Model ◽

Swat Model ◽

Agricultural Activity ◽

Dry Land ◽

Effective Measure ◽

Nps Pollution

Maoli Lake is the water source for local residents and a national nature protected area. However, due to intensive agriculture development, the water quality has deteriorated over the past decades. An effective measure to improve water quality is to control the agricultural non-point source (NPS) pollution through elaborate schemes based on eco-compensation. In order to develop such eco-compensation schemes, three scenarios of agricultural activity adjustment were designed: S1 (halving fertilization every year), S2 (fallow every other year), and S3 (returning agricultural land to forest). A Soil and Water Assessment Tool (SWAT) model was adopted to simulate runoff, total nitrogen, and total phosphorus. Based on SWAT results, a multi-criteria spatial evaluation model considering the environmental, economic, and social effects of eco-compensation was created for best scenario decision. The results reveal the following: (1) the total nutrients loss of agricultural land reduces in all scenarios, but S2 has more reduction compared to S1 and S3; (2) from the comprehensive perspective of environment–economy–society effects, S2 is the best scenario for rice land and dry land; (3) the comprehensive effect of eco-compensation at the grid scale has a significant spatial difference, and therefore, we highlight the necessity and significance of controlling agricultural NPS pollution by eco-compensation on a precise spatial scale. This study can broaden the application field of the SWAT model and provide a scientific basis and experience for the evaluation and spatial design of agriculture eco-compensation.

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Comparative Water Environment Simulation Study of Two Typical Models with BMPs in a Karst Basin

Agriculture ◽

10.3390/agriculture12010069 ◽

2022 ◽

Vol 12 (1) ◽

pp. 69

Author(s):

Jing Zhang ◽

Peiqi Zhang ◽

Yongyu Song

Keyword(s):

Water Quality ◽

River Basin ◽

Best Management Practices ◽

Management Practices ◽

Assessment Tool ◽

Swat Model ◽

Coefficient Of Determination ◽

Pollution Load ◽

Hspf Model ◽

Lijiang River

Carbonate rocks are widely distributed in southwest China, forming a unique karst landscape. The Lijiang River Basin provides a typical example of an area with concentrated karst. Research on the laws of hydrology and water quality migration in the Lijiang River Basin is important for the management of the water resources of Guilin City and similar areas. In this study, we combined three meteorological data with the soil and water assessment tool (SWAT) model and the hydrological simulation program-Fortran (HSPF) model to simulate the hydrological and water quality processes in the Lijiang River Basin separately. We chose the Nash–Sutcliffe efficiency (NSE) coefficient, coefficient of determination (R2), root mean square error-observations standard deviation ratio (RSR), and mean absolute error (MAE) as the metrics used to evaluate the models. The results, combined with the time-series process lines, indicated that the SWAT model provides a more accurate performance than the HSPF model in streamflow, ammonia nitrogen (NH3-N), and dissolved oxygen (DO) simulations. In addition, we divided the karst and non-karst areas, and we analyzed the differences between them in water balance, sediment transport, and pollution load. We further identified the key source areas of pollution load in the Lijiang River Basin, evaluated the pollution reduction effect of best management practices (BMPs) on surface source pollution, and proposed some pollution control countermeasures. Each scenario, especially returning farmland to forest and creating vegetation buffer zones, reduces the NH3-N and DO pollution load.

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Calibration and Uncertainty Analysis for Modelling Runoff in the Tambo River Basin, Peru, Using Sequential Uncertainty Fitting Ver-2 (SUFI-2) Algorithm

Air Soil and Water Research ◽

10.1177/1178622120988707 ◽

2021 ◽

Vol 14 ◽

pp. 117862212098870

Author(s):

Juan Adriel Carlos Mendoza ◽

Tamar Anaharat Chavez Alcazar ◽

Sebastián Adolfo Zuñiga Medina

Keyword(s):

River Basin ◽

Assessment Tool ◽

Hydrological Cycle ◽

Swat Model ◽

Coefficient Of Determination ◽

Economic Activities ◽

Warm Up ◽

Simulation Efficiency ◽

Basin Scale ◽

Water Assessment

Basin-scale simulation is fundamental to understand the hydrological cycle, and in identifying information essential for water management. Accordingly, the Soil and Water Assessment Tool (SWAT) model is applied to simulate runoff in the semi-arid Tambo River Basin in southern Peru, where economic activities are driven by the availability of water. The SWAT model was calibrated using the Sequential Uncertainty Fitting Ver-2 (SUFI-2) algorithm and two objective functions namely the Nash-Sutcliffe simulation efficiency (NSE), and coefficient of determination ( R2) for the period 1994 to 2001 which includes an initial warm-up period of 3 years; it was then validated for 2002 to 2016 using daily river discharge values. The best results were obtained using the objective function R2; a comparison of results of the daily and monthly performance evaluation between the calibration period and validation period showed close correspondence in the values for NSE and R2, and those for percent bias (PBIAS) and ratio of standard deviation of the observation to the root mean square error (RSR). The results thus show that the SWAT model can effectively predict runoff within the Tambo River basin. The model can also serve as a guideline for hydrology modellers, acting as a reliable tool.

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Evaluation and Hydrological Application of a Data Fusing Method of Multi-Source Precipitation Products-A Case Study Over Tuojiang River Basin

Remote Sensing ◽

10.3390/rs13132630 ◽

2021 ◽

Vol 13 (13) ◽

pp. 2630

Author(s):

Yao Li ◽

Wensheng Wang ◽

Guoqing Wang ◽

Siyi Yu

Keyword(s):

River Basin ◽

Hydrological Modeling ◽

Assessment Tool ◽

Swat Model ◽

Weighted Average ◽

Probability Of Detection ◽

Coefficient Of Determination ◽

Maximum Probability ◽

Satellite Precipitation

Precipitation is an essential driving factor of hydrological models. Its temporal and spatial resolution and reliability directly affect the accuracy of hydrological modeling. Acquiring accurate areal precipitation needs substantial ground rainfall stations in space. In many basins, ground rainfall stations are sparse and uneven, so real-time satellite precipitation products (SPPs) have become an important supplement to ground-gauged precipitation (GGP). A multi-source precipitation fusion method suitable for the Soil and Water Assessment Tool (SWAT) model has been proposed in this paper. First, the multivariate inverse distance similarity method (MIDSM) was proposed to search for the optimal representative precipitation points of GGP and SPPs in sub-basins. Subsequently, the correlation-coefficient-based weighted average method (CCBWA) was presented and applied to calculate the fused multi-source precipitation product (FMSPP), which combined GGP and multiple satellite precipitation products. The effectiveness of the FMSPP was proven over the Tuojiang River Basin. In the case study, three SPPs were chosen as the satellite precipitation sources, namely the Climate Forecast System Reanalysis (CFSR), Tropical Rainfall Measuring Mission Project (TRMM), and Precipitation Estimation from Remotely Sensed Information using Artificial Neural Network Climate Data Record (PERSIANN-CDR). The evaluation indicators illustrated that FMSPP could capture the occurrence of rainfall events very well, with a maximum Probability of Detection (POD) and Critical Success Index (CSI) of 0.92 and 0.83, respectively. Furthermore, its correlation with GGP, changing in the range of 0.84–0.96, was higher in most sub-basins on the monthly scale than the other three SPPs. These results demonstrated that the performance of FMSPP was the best compared with the original SPPs. Finally, FMSPP was applied in the SWAT model and was found to effectively drive the SWAT model in contrast with a single precipitation source. The FMSPP manifested the highest accuracy in hydrological modeling, with the Coefficient of Determination (R2) of 0.84, Nash Sutcliff (NS) of 0.83, and Percent Bias (PBIAS) of only −1.9%.

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Application of Satellite-Based and Observed Precipitation Datasets for Hydrological Simulation in the Upper Mahi River Basin of Rajasthan, India

Sustainability ◽

10.3390/su13147560 ◽

2021 ◽

Vol 13 (14) ◽

pp. 7560

Author(s):

Dinesh Singh Bhati ◽

Swatantra Kumar Dubey ◽

Devesh Sharma

Keyword(s):

River Basin ◽

Hydrological Modeling ◽

Environmental Changes ◽

Assessment Tool ◽

Swat Model ◽

Measurement Techniques ◽

Coefficient Of Determination ◽

Hydrological Simulation ◽

And Performance ◽

Trmm 3B42

Hydrological modeling is an important tool used for basin management and studying the impacts of extreme events in a river basin. In streamflow simulations, precipitation plays an essential role in hydrological models. Meteorological satellite precipitation measurement techniques provide highly accurate rainfall information with high spatial and temporal resolution. In this analysis, the tropical rainfall monitoring mission (TRMM) 3B42 V7 precipitation products were employed for simulating streamflow by using the soil water assessment tool (SWAT) model. With India Metrological Department and TRMM data, the SWAT model can be used to predict streamflow discharge and identify sensitive parameters for the Mahi basin. The SWAT model was calibrated for 2 years and then independently validated for 2 years by comparing observed and simulated streamflow. A strong correlation was observed between the calibration and validation results for the Paderdibadi station, with a Nash–Sutcliffe efficiency of >0.34 and coefficient of determination (R2) of >0.77. The SWAT model was used to adequately simulate the streamflow for the Upper Mahi basin with a satisfactory R2 value. The analysis indicated that TRMM 3B42 V7 is useful in SWAT applications for predicting streamflow and performance and for sensitivity analysis. In addition, satellite data may require correction before its utilization in hydrological modeling. This study is helpful for stakeholders in monitoring and managing agricultural, climatic, and environmental changes.

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Application of SWAT in Hydrological Simulation of Complex Mountainous River Basin (Part II: Climate Change Impact Assessment)

Water ◽

10.3390/w13111548 ◽

2021 ◽

Vol 13 (11) ◽

pp. 1548

Author(s):

Suresh Marahatta ◽

Deepak Aryal ◽

Laxmi Prasad Devkota ◽

Utsav Bhattarai ◽

Dibesh Shrestha

Keyword(s):

Climate Change ◽

River Basin ◽

Climate Models ◽

Assessment Tool ◽

Swat Model ◽

Global Climate Models ◽

Climate Data ◽

The Future ◽

The Impact ◽

Mountainous River

This study aims at analysing the impact of climate change (CC) on the river hydrology of a complex mountainous river basin—the Budhigandaki River Basin (BRB)—using the Soil and Water Assessment Tool (SWAT) hydrological model that was calibrated and validated in Part I of this research. A relatively new approach of selecting global climate models (GCMs) for each of the two selected RCPs, 4.5 (stabilization scenario) and 8.5 (high emission scenario), representing four extreme cases (warm-wet, cold-wet, warm-dry, and cold-dry conditions), was applied. Future climate data was bias corrected using a quantile mapping method. The bias-corrected GCM data were forced into the SWAT model one at a time to simulate the future flows of BRB for three 30-year time windows: Immediate Future (2021–2050), Mid Future (2046–2075), and Far Future (2070–2099). The projected flows were compared with the corresponding monthly, seasonal, annual, and fractional differences of extreme flows of the simulated baseline period (1983–2012). The results showed that future long-term average annual flows are expected to increase in all climatic conditions for both RCPs compared to the baseline. The range of predicted changes in future monthly, seasonal, and annual flows shows high uncertainty. The comparative frequency analysis of the annual one-day-maximum and -minimum flows shows increased high flows and decreased low flows in the future. These results imply the necessity for design modifications in hydraulic structures as well as the preference of storage over run-of-river water resources development projects in the study basin from the perspective of climate resilience.

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Development and Verification of the Available Number of Water Intake Days in Ungauged Local Water Source Using the SWAT Model and Flow Recession Curves

Water ◽

10.3390/w13111511 ◽

2021 ◽

Vol 13 (11) ◽

pp. 1511

Author(s):

Jung-Ryel Choi ◽

Il-Moon Chung ◽

Se-Jin Jeung ◽

Kyung-Su Choo ◽

Cheong-Hyeon Oh ◽

...

Keyword(s):

Water Supply ◽

Water Intake ◽

Water Resource Management ◽

Assessment Tool ◽

Swat Model ◽

High Water ◽

Coefficient Of Determination ◽

Severe Drought ◽

Regional Government

Climate change significantly affects water supply availability due to changes in the magnitude and seasonality of runoff and severe drought events. In the case of Korea, despite high water supply ratio, more populations have continued to suffer from restricted regional water supplies. Though Korea enacted the Long-Term Comprehensive Water Resources Plan, a field survey revealed that the regional government organizations limitedly utilized their drought-related data. These limitations present a need for a system that provides a more intuitive drought review, enabling a more prompt response. Thus, this study presents a rating curve for the available number of water intake days per flow, and reviews and calibrates the Soil and Water Assessment Tool (SWAT) model mediators, and found that the coefficient of determination, Nash–Sutcliffe efficiency (NSE), and percent bias (PBIAS) from 2007 to 2011 were at 0.92, 0.84, and 7.2%, respectively, which were “very good” levels. The flow recession curve was proposed after calculating the daily long-term flow and extracted the flow recession trends during days without precipitation. In addition, the SWAT model’s flow data enables the quantitative evaluations of the number of available water intake days without precipitation because of the high hit rate when comparing the available number of water intake days with the limited water supply period near the study watershed. Thus, this study can improve drought response and water resource management plans.

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