Identifying potential rainwater harvesting sites in Sarab Seid Ali watershed of Alashtar usingtwo GIS based methods of NRCS-CN and decision support system (DSS)

Runoff Collect used for to minimize losses and strengthen water resources in watersheds.Countries like some areas of Iran are facing to water scarcity, faced with Unsuitable distribution of rainfall. By expanding the use of water sources, using the principles of runoff from rainfall can be effective to solve the problem of water shortage.In order to estimate the runoff in watershedsthere are several experimental methods and mathematical models. One of these models is Curve Number Model (NRCS) that in this study, is production base of runoff maps. The purpose of this research is Identifying potential rainwater harvesting sites (Artificial recharge of aquifers by percolation ponds and surface storage of runoff by Gradin andterracing) in Sarab Seid ali watershed of Alashtar by (NRCS - CN) method. this means that in the GIS software environment after mapping the runoff used of other six layers of information contain: Geology , Fault , Drainage density , Land use , Soil texture and slope and used ofIF , WOAmethods forweighting, rating and integrating existing7Layerand from the final maps of the two methods select maps with more accurate and with considering economic – Social issuesIncorporation with 3 Map ofdistance from irrigated lands , drylands and residential areas in the form of a decision support system (DSS) and The final maps of suitable areas for artificial recharge and surface storage of rainwater became harvest.