Comparing the Analytic Hierarchy Process (AHP) and fuzzy logic for zoning the risk of gully erosion in the three regions of the Ardebil province

Gully erosion is the most advanced water erosion in watersheds that produce large volumes of sediment can cause serious damage. In order to manage and cope with this type of erosion, to identify areas of high risk of gully erosion in the watershed is very important. For this purpose gully erosion hazard zonation maps by combining information layers of different factors affecting the formation of gullies is prepared on the basis of their importance. Analytic hierarchy process (AHP) and fuzzy Gamma operator new and useful methods for weighting and combining various layers of information. This study aimed to compare two methods of zoning with AHP and fuzzy gamma 0.8 in three watersheds in the name of Orta dagh, Molla ahmd and Sarcham was conducted in Ardabil province. For zoning from eight factor include slope, aspect, elevation, land use, Plant cover, geology, distance from roads and distance from waterways that are important factors affecting the formation of gullies were used. For comparison of two methods to accurately determine the zoning of the area, two compression density ratios (Dr) and quality sum (Qs) was used. The results showed that in all three areas fuzzy method is more accurate, AHP method are careful in the two Orta dagh and molla ahmad area but in sarcham did not workable.  In general for zoning of gully erosion risk using fuzzy gamma was suitable. However, if selection and weighting factors influenced the formation of gullies has careful, AHP can was a good method.