SWAT Literature Database for Peer-Reviewed Journal Articles

Title:Assessment of integrated watershed health based on the natural environment, hydrology, water quality, and aquatic ecology 
Authors:Ahn, S.R. and S.J. Joon Kim 
Journal:Hydrology and Earth System Sciences 
Volume (Issue):21 
Article ID: 
URL (non-DOI journals): 
Broad Application Category:hydrologic and pollutant 
Primary Application Category:hydrologic, pollutant and/or crop indices (or metrics) 
Secondary Application Category:pollutant cycling/loss and transport 
Watershed Description:34,148 km^2 Han River, which drains much of north central South Korea. 
Calibration Summary: 
Validation Summary: 
General Comments: 
Abstract:Watershed health, including the natural environment, hydrology, water quality, and aquatic ecology, is assessed for the Han River basin (34148 km2) in South Korea by using the Soil and Water Assessment Tool (SWAT). The evaluation procedures follow those of the Healthy Watersheds Assessment by the U.S. Environmental Protection Agency (EPA). Six components of the watershed landscape are examined to evaluate the watershed health (basin natural capacity): stream geomorphology, hydrology, water quality, aquatic habitat condition, and biological condition. In particular, the SWAT is applied to the study basin for the hydrology and water-quality components, including 237 subwatersheds (within a standard watershed on the Korea Hydrologic Unit Map) along with three multipurpose dams, one hydroelectric dam, and three multifunction weirs. The SWAT is calibrated (2005–2009) and validated (2010–2014) by using each dam and weir operation, the flux-tower evapotranspiration, the time-domain reflectometry (TDR) soil moisture, and groundwater-level data for the hydrology assessment, and by using sediment, total phosphorus, and total nitrogen data for the water-quality assessment. The water balance, which considers the surface–groundwater interactions and variations in the stream-water quality, is quantified according to the sub-watershed-scale relationship between the watershed hydrologic cycle and stream-water quality.We assess the integrated watershed health according to the U.S. EPA evaluation process based on the vulnerability levels of the natural environment, water resources, water quality, and ecosystem components. The results indicate that the watershed’s health declined during the most recent 10-year period of 2005–2014, as indicated by the worse results for the to those of the 1995–2004 period. The integrated watershed health tended to decrease farther downstream within the watershed. surface process metric and soil water dynamics compare