Application of fuzzy representation of geographic boundary to the soil loss model

Abstract. The polygon boundaries on the digital map of land surface characteristic are conventionally represented as a sharp change (categorical format), which results in discrepancy between real world phenomena and the information presented by boundaries on map, and it is especially true for soil properties. This paper presents a probable impact of the representation of geographic boundary for the soil loss model. To do this, the Revise Universal Soil Loss Equation (RUSLE) model is facilitated at a small basin in Korea and then the fuzzy representation of geographic boundary, which is presumably better description of soil properties in nature, was introduced into the soil factors in the RUSLE. The model results were compared to the conventional representation of sharp change in relative terms. The model results show the impact of the fuzzy representation on the RUSLE model is considerable and the soil loss model is expected to use more realistic description for geographic boundaries of land surface characteristics. The method suggested herein is relatively simple and has wide applicability.