To select suitable sites of runoff harvesting for Qanats recharge (A case of study: Kalat watershed of Gonabad)

One of the proper strategies to preserve and revive qanats is harmonic improvement and development of the utilization systems with qanat natural conditions. One of the most suitable strategies is artificial recharge of qanats aquifer with use of runoff water harvesting systems. In this paper in order to identify the suitable sites for qanats recharge، determined the suitable sites of runoff water harvesting by means of Geographical Information System (GIS) in watershed Kalat of Gonabad. For this purpose modeled and evaluated generation of runoff potential with consideration of spatial variations in characteristics such as soil، land use، rainfall and slope information in GIS. With integrate layers in GIS، computed the ratio of area qanat recharge sites to area runoff concentrating sites and site for distributed stored water. The results show that 68. 4 percent of the Kalat watershed area has a high and very high potential for generation surface runoff، whereas only 2. 8 percent of total area have suitability of high and very high for qanats recharge and distance of Qanat is the only cramp factor for this purpose. In addition to the Geographic Information System could be an efficiency and useful tool to determine proper sites for Qanat recharge.