PT  - JOURNAL ARTICLE
AU  - M.F. Winchell
AU  - S.H. Jackson
AU  - A.M. Wadley
AU  - R. Srinivasan
TI  - Extension and validation of a geographic information system-based method for calculating the Revised Universal Soil Loss Equation length-slope factor for erosion risk assessments in large watersheds
AID  - 10.2489/jswc.63.3.105
DP  - 2008 May 01
TA  - Journal of Soil and Water Conservation
PG  - 105--111
VI  - 63
IP  - 3
4099  - http://www.jswconline.org/content/63/3/105.short
4100  - http://www.jswconline.org/content/63/3/105.full
AB  - A geographic information system-based (GIS) method for estimating the length-slope (LS) factor of the Revised Universal Soil Loss Equation using national-scale datasets was developed and validated. The method was applied to approximately two-thirds of the Mississippi River basin, focusing on agricultural subwatersheds in the Midwest. The results were validated by comparing the GIS-based statistical distributions of LS-factor values with the distribution of LS-factors calculated from the Natural Resources Inventory database at the eight-digit watershed level. The GIS-based approach was shown to produce statistical distributions of LS-factor values very similar to those described by the Natural Resources Inventory database of field measurements, providing for the first time strong support for using GIS-based methods to represent the spatial heterogeneity and magnitude of LS-factors. Development and validation of the GIS-based approach is an important step toward conducting large-scale erosion potential assessments that have soil conservation implications in natural resources management, agronomy, and agrochemical exposure risk assessments.