SWAT Literature Database for Peer-Reviewed Journal Articles

Title:Watershed-scale hydrologic and nonpoint-source pollution models: Review of applications 
Authors:Borah, D.K. and M. Bera 
Journal:Transactions of the ASAE 
Volume (Issue):47(3) 
Article ID: 
URL (non-DOI journals): 
Broad Application Category:review/history 
Primary Application Category:model comparison 
Secondary Application Category:pollutant cycling/loss and transport 
Watershed Description:None 
Calibration Summary: 
Validation Summary: 
General Comments:17, 12, & 17 applications of the SWAT, HSPF, & DWSM MODELS were reviewed. SWAT & HSPF were found to be suitable for predicting annual and monthly flows & pollutant loads, except for months with extreme storm events. DWSM, however, was found to adequately replicate daily sotrm events. The authors state that combining routines from different models is warranted to address full range of different water quality problems. 
Abstract:Three watershed-scale hydrologic and nonpoint-source pollution models, all having the three major components (hydrology, sediment, and chemical), were selected based on a review of eleven models (AGNPS, AnnAGNPS, ANSWERS, ANSWERS-Continuous, CASC2D, DWSM, HSPF, KINEROS, MIKE SHE, PRMS, and SWAT) presented in a companion article. Those selected were SWAT, a promising model for long-term continuous simulations in predominantly agricultural watersheds; HSPF, a promising model for long-term continuous simulations in mixed agricultural and urban watersheds; and DWSM, a promising storm event (rainfall) simulation model for agricultural and suburban watersheds. In this article, applications of these three models, as reported and found in the literature, are reviewed and discussed. Seventeen SWAT, twelve HSPF, and eighteen DWSM applications are compiled. SWAT and HSPF require a significant amount of data and empirical parameters for development and calibration. DWSM has efficient physically (process) based simulation routines and therefore has a small number of calibration parameters. SWAT and HSPF were found suitable for predicting yearly flow volumes, sediment, and nutrient loads. Monthly predictions were generally good, except for months having extreme storm events and hydrologic conditions. Daily simulations of extreme flow events were poor. DWSM reasonably predicted distributed flow hydrographs, and concentration or discharge graphs of sediment, nutrient, and pesticides at small time intervals resulting from rainfall events. Combined use of these complementary models and perhaps other models having different strengths is warranted to adequately address water quantity and quality problems and their solutions. 
Keywords:Agrochemical, Continuous modeling, Hydrology, Model applications, Nonpoint-source pollution, Sediment, Storm event modeling, Water quality, Watershed