Evaluate the performance of the Soil Vulnerability Index using a high spatial resolution hydrological model.

Authors: PHUNG, QUANG - University Of Missouri; ALOYSIUS, NOEL - University Of Missouri; Baffaut, Claire; THOMPSON, ALLEN - University Of Missouri; THAASAN, THAKSHAJINI - University Of Missouri; WILLIAMS, ANDREW - University Of Missouri; FRITZ, VERONICA - University Of Missouri; BLODGETT, CLAIRE - University Of Missouri

Submitted to: American Geophysical Union Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 10/30/2020
Publication Date: 12/1/2020
Citation: Phung, Q., Aloysius, N.R., Baffaut, C., Thompson, A., Thaasan, T., Williams, A.M., Fritz, V., Blodgett, C. 2020. Evaluate the performance of the Soil Vulnerability Index using a high spatial resolution hydrological model [abstract]. American Geophysical Union Fall Meeting, December 1-17, 2020. Available: https://agu.confex.com/agu/fm20/meetingapp.cgi/Paper/755746

Interpretive Summary:

Technical Abstract: Soil erosion and fertilizer loss from landscapes via runoff and leaching contribute to the deterioration of water quality in aquatic systems. The Soil Vulnerability Index (SVI) was developed by the US Department of Agriculture Natural Resources Conservation Service (NRCS) to help conservation planners quickly and accurately identify vulnerable areas to excessive fertilizer and sediment runoff and leaching. While the SVI is proposed to be used throughout the United States, the index was developed based on the physiographic and hydrological conditions of the Upper Mississippi and Ohio-Tennessee River basins. Thus, there is a need to evaluate the effectiveness of the SVI model for regions elsewhere. Here, we propose to evaluate the performance of the SVI on predicting surface runoff and leaching in the Mississippi River Basin (MRB). The MRB was chosen as the study area because (i) nonpoint sources of fertilizer and sediment contribute significantly to the Gulf of Mexico Hypoxic zone, and (ii) federal and state agencies are interested in identifying excessive runoff areas in order to implement conservation practices. In addition, the MRB represents the physiographic and hydrological conditions both within and outside of the SVI’s area of study. A high-definition watershed-scale hydrology and biogeochemical cycling mode is being developed to simulate the watershed response in order to evaluate the SVI performance at finer spatial scales. The MRB is divided into 80,000+ hydrologic response units. Actual land management practices, including crops cultivated and fertilizer application rates are compiled based on annual land use maps for the period 2010-2019. Grid based weather data from the North American Land Data Assimilation System (NLDAS) are used to simulate the watershed processes at daily time steps. Results from this study will help to evaluate the performance of the SVI, and to identify critical source areas of pollution within the MRB.