Estimation of soil erosion using SLEMSA model and OWA approach in Lorestan Province (Iran)

Identifying suitable models for estimating soil erosion is one of the most importantissues facing decision makers and managers in comprehensive planning and management ofsoil and water. In this research, with the purpose of estimating soil erosion in LorestanProvince, the conventional SLEMSA method was jointly used with OWA (orderedweighted averaging) multi-criteria evaluation method. The results showed that in theSLEMSA model, erosion classes with very low and very high erosion rates with an area of۱۶۳۳۴ and ۱۶۷ km۲, covered the largest (۵۸.۷%) and the smallest areas of the region (۰.۶%),respectively. In the OWA method, on average, ۶۳.۶۷% of the area covering ۱۸۰۰۷ km۲ waslocated in a very low erosion class, while the very high erosion class with an area of ۹۵۶.۵km۲, comprised ۵.۸۵% of the study area. The results of this research showed that besidesusing the SLEMSA model, the OWA method introducing a decision environment with riskand uncertainties can be used to estimate erosion, and its output can lead to a relativelyprecise assessment of the soil erosion in a short time and at a low cost for a vast area likeLorestan Province.