Mapping runoff generating areas using AGNPS-VSA model. Issue 13 (2nd October 2020)

• Record Type: Journal Article
• Authors: Panjabi, Kishor; Rudra, Ramesh; Goel, Pradeep; Daggupati, Prasad; Shrestha, Narayan Kumar; Shukla, Rituraj; Zhang, Binbin; Allataifeh, Nabil
• Is Part Of: Hydrological sciences journal. Volume 65:Issue 13(2020)
• Page Start: 2224
• Page End: 2232
• Publication Date: 2020-10-02
• Subjects: AGricultural Non-Point Source Pollution (AGNPS) model -- variable source areas (VSA) -- topographic wetness index (TWI) -- saturation excess -- infiltration excess; Hydrology -- Periodicals; 551.4805
• DOI: 10.1080/02626667.2020.1798007
• Languages: English
• ISSNs: 0262-6667

Abstract

ABSTRACT: In humid regions, surface runoff is often generated by saturation-excess runoff mechanisms from relatively small variable source areas (VSAs). However, the majority of the current hydrologic models are based on infiltration-excess mechanisms. In this study, the AGricultural Non-Point Source Pollution (AGNPS) model was used to integrate the VSA concept using topographic wetness index (TWI). Both the original and AGNPS-VSA models were evaluated for a small agricultural field in Ontario, Canada. The results indicate that the AGNPS-VSA model performed better than original model. The AGNPS-VSA model predicted that only the saturated portion of the field with higher TWI values produced runoff, whereas the original AGNPS model showed uniform hydrologic response from the entire field. The results of this study are important for accurately mapping the locations of VSAs. This new model could be a powerful tool in identifying critical source areas for applying targeted best management practices to minimize pollutant loads to receiving waters.