20190714 19210400 1.0 TRUE Soil Erosion Index 24-30in The Soil Erosion Index maps provide users with a visual interpretation of how susceptible a given soil type is to water erosion. Soil Erosion Index 24”-30” assesses how susceptible a given soil type is to water erosion with the top horizons removed as you would find on a construction site. United States Department of Agriculture - Natural Resources Conservation Service, State of Rhode Island, RIGIS.