TY - JOUR
T1 - Simulating hydrological and nonpoint source pollution processes in a karst watershed
T2 - A variable source area hydrology model evaluation
AU - Amin, M. G.Mostofa
AU - Veith, Tamie L.
AU - Collick, Amy S.
AU - Karsten, Heather D.
AU - Buda, Anthony R.
N1 - Funding Information:
This publication was developed under Assistance Agreement No. RD 83556801-0 awarded by the US Environmental Protection Agency (EPA) to the Center for Nutrient Solutions, Penn State University, USA. It has not been formally reviewed by EPA. We also acknowledge the support from the Department of Plant Science, Penn State University and USDA-ARS , Pasture Systems and Watershed Management Research Unit, University Park, PA 16802, USA . We are also grateful to the Chesapeake Community Modeling Program. Mention of trade names or commercial products in this publication is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the US Department of Agriculture, EPA, Penn State University, or University of Maryland − Eastern Shore. All entities involved are equal opportunity providers and employers.
Publisher Copyright:
© 2016
PY - 2017/1/31
Y1 - 2017/1/31
N2 - An ecohydrological watershed model can be used to develop an efficient watershed management plan for improving water quality. However, karst geology poses unique challenges in accurately simulating management impacts to both surface and groundwater hydrology. Two versions of the Soil and Water Assessment Tool (SWAT), Regular-SWAT and Topo-SWAT (which incorporates variable source area hydrology), were assessed for their robustness in simulating hydrology of the karstic Spring Creek watershed of Centre County, Pennsylvania, USA. Appropriate representations of surface water – groundwater interactions and of spring recharge – discharge areas were critical for simulating this karst watershed. Both Regular-SWAT and Topo-SWAT described the watershed discharge adequately with daily Nash-Sutcliffe efficiencies (NSE) ranging from 0.77 to 0.79 for calibration and 0.68–0.73 for validation, respectively. Because Topo-SWAT more accurately represented measured daily streamflow, with statistically significant improvement of NSE over Regular-SWAT during validation (p-value = 0.05) and, unlike Regular-SWAT, had the capability of spatially mapping recharge/infiltration and runoff generation areas within the watershed, Topo-SWAT was selected to predict nutrient and sediment loads. Total watershed load estimates (518 t nitrogen/year, 45 t phosphorus/year, and 13600 t sediment/year) were within 10% of observed values (−9.2% percent bias for nitrogen, 6.6% for phosphorous, and 5.4% for sediment). Nutrient distributions among transport pathways, such as leaching and overland flow, corresponded with observed values. This study demonstrates that Topo-SWAT can be a valuable tool in future studies of agricultural land management change in karst regions.
AB - An ecohydrological watershed model can be used to develop an efficient watershed management plan for improving water quality. However, karst geology poses unique challenges in accurately simulating management impacts to both surface and groundwater hydrology. Two versions of the Soil and Water Assessment Tool (SWAT), Regular-SWAT and Topo-SWAT (which incorporates variable source area hydrology), were assessed for their robustness in simulating hydrology of the karstic Spring Creek watershed of Centre County, Pennsylvania, USA. Appropriate representations of surface water – groundwater interactions and of spring recharge – discharge areas were critical for simulating this karst watershed. Both Regular-SWAT and Topo-SWAT described the watershed discharge adequately with daily Nash-Sutcliffe efficiencies (NSE) ranging from 0.77 to 0.79 for calibration and 0.68–0.73 for validation, respectively. Because Topo-SWAT more accurately represented measured daily streamflow, with statistically significant improvement of NSE over Regular-SWAT during validation (p-value = 0.05) and, unlike Regular-SWAT, had the capability of spatially mapping recharge/infiltration and runoff generation areas within the watershed, Topo-SWAT was selected to predict nutrient and sediment loads. Total watershed load estimates (518 t nitrogen/year, 45 t phosphorus/year, and 13600 t sediment/year) were within 10% of observed values (−9.2% percent bias for nitrogen, 6.6% for phosphorous, and 5.4% for sediment). Nutrient distributions among transport pathways, such as leaching and overland flow, corresponded with observed values. This study demonstrates that Topo-SWAT can be a valuable tool in future studies of agricultural land management change in karst regions.
UR - http://www.scopus.com/inward/record.url?scp=85027942735&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85027942735&partnerID=8YFLogxK
U2 - 10.1016/j.agwat.2016.07.011
DO - 10.1016/j.agwat.2016.07.011
M3 - Article
AN - SCOPUS:85027942735
SN - 0378-3774
VL - 180
SP - 212
EP - 223
JO - Agricultural Water Management
JF - Agricultural Water Management
ER -