Site selection suitable for earth small dam by use criterion elimination and AHP (Kal Aji Watershed, Golestan Province)

In the many of region the world special arid and semi-arid region، small earth dam construction is one of the effectively suggestion to solution difficult water deficit and contrast whit big floodwaters in the watery season. In this field RS (Remote Sensing) technique can provide useful information with high spatial and temporal resolution special region without data in place accessible. In this research steps and efficient criteria to for site selection to construction earth dams be suggested. Selection criteria divided defined two classes include quantitative and qualitative and based on the region analyses and be calculation by using a RS data (Image، DEM) and hydrology and geomorphology data. Qualitative criteria used to identify valley and based on visual explanation of satellite image and large scale maps. Quantitative criteria expressed in term of α، β and P. Morphology index (α) is the benefit to cost (B/C)، Hydrology index (P) is based on participative watersheds analysis and rainfall pattern in the region. β index is combination of morphology and hydrology aspect. In the Kal Aji watershed of Golestan province، from 56 selected site، in the first step 27 site could passed suggested criteria and finally remaining sites prioritized based on Paired comparisons and Weighting whit Expert Choice software. Finally be assignable base of Weighting calculate software and field survey، 34، 24 and 42 site are contain upper prioritize in the region for construction small earth dam. In the many of region the world special arid and semi-arid region، small earth dam construction is one of the effectively suggestion to solution difficult water deficit and contrast whit big floodwaters in the watery season. In this field RS (Remote Sensing) technique can provide useful information with high spatial and temporal resolution special region without data in place accessible. In this research steps and efficient criteria to for site selection to construction earth dams be suggested. Selection criteria divided defined two classes include quantitative and qualitative and based on the region analyses and be calculation by using a RS data (Image، DEM) and hydrology and geomorphology data. Qualitative criteria used to identify valley and based on visual explanation of satellite image and large scale maps. Quantitative criteria expressed in term of α، β and P. Morphology index (α) is the benefit to cost (B/C)، Hydrology index (P) is based on participative watersheds analysis and rainfall pattern in the region. β index is combination of morphology and hydrology aspect. In the Kal Aji watershed of Golestan province، from 56 selected site، in the first step 27 site could passed suggested criteria and finally remaining sites prioritized based on Paired comparisons and Weighting whit Expert Choice software. Finally be assignable base of Weighting calculate software and field survey، 34، 24 and 42 site are contain upper prioritize in the region for construction small earth dam.