Prioritization of Sub-Watersheds based on Morphometric Analysis,GIS and RS Techniques: Lohandar Watershed, Golestan Province

Subwatersheds prioritization is the important procedure in natural resource comprehensive management and sustainable development. In this research prioritization the 11 subwatershed of Lohandar that located in east of Golestan province with 272. 63 km2 using GIS، RS and morphometric analysis. Erosion condition became clear in the each sub watershed. Morphometric analysis includes stream length، bifurcation ratio، drainage density، shape coefficient، circularity coefficient، elongation coefficient and compactness coefficient. Morphometric parameters included two parts (linear and shape coefficient). The preference of each sub watershed was determined using SYI and morphometric parameters. For calculation SYI index using several maps such as land use، land cover، slope، soil texture and 1:50000 topographic map. Finally determination any sub watershed priority by attention to amounts SYI index and total mean Morphometric parameters، that B5 sub watershed from morphometric parameter and A5 from SYI parameter have critical condition and incorporation of these two parameters delineate that B2 has worst condition.