Modified SWAT Model for Agricultural Watershed in Karst Area of Southwest China

The Soil and Water Assessment Tool (SWAT) model is extensively used globally for hydrological and water quality assessments but encounters challenges in karst regions due to their complex surface and groundwater hydrological environments. This study aims to refine the delineation of hydrological res...

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Main Authors: Junfeng Dai, Linyan Pan, Yan Deng, Zupeng Wan, Rui Xia
Format: Article
Language:English
Published: MDPI AG 2025-01-01
Series:Agriculture
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Online Access:https://www.mdpi.com/2077-0472/15/2/192
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author Junfeng Dai
Linyan Pan
Yan Deng
Zupeng Wan
Rui Xia
author_facet Junfeng Dai
Linyan Pan
Yan Deng
Zupeng Wan
Rui Xia
author_sort Junfeng Dai
collection DOAJ
description The Soil and Water Assessment Tool (SWAT) model is extensively used globally for hydrological and water quality assessments but encounters challenges in karst regions due to their complex surface and groundwater hydrological environments. This study aims to refine the delineation of hydrological response units within the SWAT model by combining geomorphological classification and to enhance the model with an epikarst zone hydrological process module, exploring the accuracy improvement of SWAT model simulations in karst regions of Southwest China. Compared with the simulation results of the original SWAT model, we simulated runoff and nutrient concentrations in the Mudong watershed from January 2017 to December 2021 using the improved SWAT model. The simulation results indicated that the modified SWAT model responded more rapidly to precipitation events, particularly in bare karst landform, aligning more closely with the actual hydrological processes in Southwest China’s karst regions. In terms of the predictive accuracy for monthly loads of total nitrogen (TN) and total phosphorus (TP), the coefficient of determination (R<sup>2</sup>) value of the modified model increased by 10.3% and 9.7%, respectively, and the Nash–Sutcliffe efficiency coefficient (NSE) increased by 11.3% and 9.9%, respectively. The modified SWAT model improves prediction accuracy in karst areas and holds significant practical value for guiding non-point source pollution control in agricultural watersheds.
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institution Kabale University
issn 2077-0472
language English
publishDate 2025-01-01
publisher MDPI AG
record_format Article
series Agriculture
spelling doaj-art-d0b29e42054e4d39945632398e528a722025-01-24T13:16:04ZengMDPI AGAgriculture2077-04722025-01-0115219210.3390/agriculture15020192Modified SWAT Model for Agricultural Watershed in Karst Area of Southwest ChinaJunfeng Dai0Linyan Pan1Yan Deng2Zupeng Wan3Rui Xia4Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology, Guilin University of Technology, Guilin 541004, ChinaCollege of Environment and Resources, Guangxi Normal University, Guilin 541006, ChinaCollege of Environment and Resources, Guangxi Normal University, Guilin 541006, ChinaGuangxi Key Laboratory of Environmental Pollution Control Theory and Technology, Guilin University of Technology, Guilin 541004, ChinaChinese Research Academy of Environmental Sciences, Beijing 100012, ChinaThe Soil and Water Assessment Tool (SWAT) model is extensively used globally for hydrological and water quality assessments but encounters challenges in karst regions due to their complex surface and groundwater hydrological environments. This study aims to refine the delineation of hydrological response units within the SWAT model by combining geomorphological classification and to enhance the model with an epikarst zone hydrological process module, exploring the accuracy improvement of SWAT model simulations in karst regions of Southwest China. Compared with the simulation results of the original SWAT model, we simulated runoff and nutrient concentrations in the Mudong watershed from January 2017 to December 2021 using the improved SWAT model. The simulation results indicated that the modified SWAT model responded more rapidly to precipitation events, particularly in bare karst landform, aligning more closely with the actual hydrological processes in Southwest China’s karst regions. In terms of the predictive accuracy for monthly loads of total nitrogen (TN) and total phosphorus (TP), the coefficient of determination (R<sup>2</sup>) value of the modified model increased by 10.3% and 9.7%, respectively, and the Nash–Sutcliffe efficiency coefficient (NSE) increased by 11.3% and 9.9%, respectively. The modified SWAT model improves prediction accuracy in karst areas and holds significant practical value for guiding non-point source pollution control in agricultural watersheds.https://www.mdpi.com/2077-0472/15/2/192modified SWATnon-point source pollutionkarstagriculture
spellingShingle Junfeng Dai
Linyan Pan
Yan Deng
Zupeng Wan
Rui Xia
Modified SWAT Model for Agricultural Watershed in Karst Area of Southwest China
Agriculture
modified SWAT
non-point source pollution
karst
agriculture
title Modified SWAT Model for Agricultural Watershed in Karst Area of Southwest China
title_full Modified SWAT Model for Agricultural Watershed in Karst Area of Southwest China
title_fullStr Modified SWAT Model for Agricultural Watershed in Karst Area of Southwest China
title_full_unstemmed Modified SWAT Model for Agricultural Watershed in Karst Area of Southwest China
title_short Modified SWAT Model for Agricultural Watershed in Karst Area of Southwest China
title_sort modified swat model for agricultural watershed in karst area of southwest china
topic modified SWAT
non-point source pollution
karst
agriculture
url https://www.mdpi.com/2077-0472/15/2/192
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AT linyanpan modifiedswatmodelforagriculturalwatershedinkarstareaofsouthwestchina
AT yandeng modifiedswatmodelforagriculturalwatershedinkarstareaofsouthwestchina
AT zupengwan modifiedswatmodelforagriculturalwatershedinkarstareaofsouthwestchina
AT ruixia modifiedswatmodelforagriculturalwatershedinkarstareaofsouthwestchina