GIS-based erosion risk assessment of the Şebinkarahisar (Giresun) and surroundings

The purpose of the this thesis is to make an erosion risk assesment of an area around Şebinkarahisar (GİRESUN) by Geographical Information System (GIS) and remote sensing techniques.In this study, four main data set such as Lansad 5 TM (2001) satellite images and 1/25000 scale geological maps and greater soil grups map and rain fall data of the surveying area were used. From the digital topographical sheets, slope gradients and digital elevation model was optained. In order to generate land use map from the surveying area , to determin higher risc regionns, the RUSLE model were used. For his purpose, rain fall data , soil erodibility factor, slope length and gradient, land cover factor, erosion control application factor data are generated. In the determination of errosive effect of rainfall data are optained from ?State Meteorological Service?. The relation beween Grater Land Groups and gradient taking into account, erodibility classes in the Grater Land Groups are used. In the determining of soil erodibility factor from early works made in Turkey are used. According to Conrad (2002) slope legth and gradient are optained by DIGEM software program. In order to determine erosion control application factors, even if partly precaution were taken in to account, the P value in agricultural land is 0.5 and in forests and settling areas is assigned as 1. This map contains erosion susceptible classes of the surveying area.