Lithology effects on gully erosion in Ghoori chay Watershed using RS & GIS?

摘要

Gullyerosion, which is themost damagingeffecton soil, is occurred in agricultural lands in Iran and caused diminishing soil fertilityand filling damsand reservoirs,also it is a threateningfor roads,buildings andagriculturallands.Gullies are the extensive kind of soil erosion and for controlling it, you should know the factors effects on gully extension. One of the factors which control erosion in watersheds is lithological characteristics of the watershed.In this study, after digitizing the lithological map by using ILWIS3.4software,resistancetocorrosioncoefficient factor and the map of erosionsusceptibility wasobtained.The map of gully erosion in watershed was prepared based on the Fieldtrialsby GPS, IRS, satellite imagesandaerial photographs.Finally, by using statistical analysis, the map of susceptible to erosion in ILWIS software was segmented with the gully erosion map. Results showed high Correlation coefficient with 0.97 and indicated gully erosion in Ghoorichay watershed is more influenced by the kind of lithological structure