Investigation of runoff production capacity from rocky surfaces of the watershed for supplementary irrigationCase study: Haft Bagh Alavi watershed in Kerman

Most of the rainfall in arid and semi-arid regions, which becomes runoff immediately after rainfall, eventually evaporates and becomes inaccessible. Harvesting water from impermeable rock surfaces and storage in reservoirs or aquifer feeding is an effective way to prevent evaporation losses in these areas. The purpose of this study is to model the amount of runoff in sub-basins with impermeable surfaces in the Haft Bagh Alavi area of Kerman to estimate the volume of harvestable runoff in this area. Haft Bagh Alavi watershed is located 26 km from Kerman and has an area of 14923 hectares. About 18.3%, equivalent to 2732 hectares of the basin area has a rock mass level of more than 90%. HEC-HMS software has been used to model rainfall-runoff in the basin. The area curve number of soil, slope, and land use information was entered into the model. 30-year mean evapotranspiration data, with the 30-year mean of 10-minute precipitation data, were collected from the automatic station and used as input. The results showed that by harvesting only 10% of the total average annual cumulative runoff of four sub-basins, it is possible to collect 8.055 million cubic meters of water and provide water for supplementary irrigation of 16,110 hectares of gardens.