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ARS Home » Midwest Area » Columbia, Missouri » Cropping Systems and Water Quality Research » Research » Publications at this Location » Publication #401987
Research Project: Linkages Between Crop Production Management and Sustainability in the Central Mississippi River Basin

Location: Cropping Systems and Water Quality Research

Title: Adjustment of the Soil Vulnerability Index Classification to account for precipitation

Author
item Baffaut, Claire
item THOMPSON, ALLEN - University Of Missouri
item PHUNG, QUANG - University Of Missouri

Submitted to: Soil and Water Conservation Society International Annual Conference
Publication Type: Abstract Only
Publication Acceptance Date: 2/8/2023
Publication Date: 8/6/2023
Citation: Baffaut, C., Thompson, A., Phung, Q. 2023. Adjustment of the Soil Vulnerability Index Classification to account for precipitation [abstract]. 78th Soil and Water Conservation Society International Annual Conference, August 6-9, 2023, Des Moines, Iowa. p. 25.

Interpretive Summary:

Technical Abstract: The Soil Vulnerability Index (SVI) developed by NRCS uses available soil properties from the SSURGO database to classify agricultural land into four levels of vulnerability to sediment and nutrient losses: low, moderate, moderately high, and high. It includes multiple components, including the runoff component, which is based on the risk of sediment from cropland being discharged into the streams. Improvements in assigning vulnerability classification by including rainfall characteristics have been suggested. The objective of this research was to evaluate rainfall characteristics on the runoff component of SVI, with the goal to improve SVI vulnerability classification. The study simulated sediment yields using three calibrated models developed with the Soil and Water Assessment Tool (SWAT). These models represent three Conservation Effects Assessment Project (CEAP) watersheds having a range of physiographic and hydrologic characteristics in Missouri, Ohio, and Pennsylvania. Sediment yields from these watersheds were simulated using precipitation data from 1985 to 2014 from 11 different CEAP watersheds spanning Texas to Vermont, Georgia, and Mississippi. Classifications based on simulated sediment yields were evaluated across a range of landscape slopes. Results indicate that the risk of sediment discharge into the streams can shift up or down due to precipitation amount, intensity, and R-factor, and this shift is more pronounced for steeper slopes. The changing sediment loss is better correlated with precipitation characteristics in northern than in southern states. Possible modifications in the SVI classification rule-set to account for these differences are proposed.