Erosion potential

Water resources and their appropriate exploitation are among important and critical issues in deserts and semi-desert areas. Qom has always faced water shortage and Panzdah-e Khordad Dam was built between Qom and Delijan to resolve the problem. This dam faces lots of sedimentation. This inevitably results in dam filling and shortening of its useful life. Therefore, studying erodibility potential in upstream basin is essential. The present study primarily seeks to divide the basin into different zones based on formations sensitivity to erosion and their role in the creation of new sediments. To reach this goal, boundaries of Panzdah-e Khordad Dam basin were identified using 1:50000 topographic maps. Then, it was carefully implemented on 1:50000 geological map of Qom-Delijan. After producing geological maps, channels, precipitation, geomorphology, slope and soil permeability were digitalized. Then, erodibility intensity in Panzdah-e Khordad Dam basin was produced using GIS, layer scoring and integrating techniques (Overlay index). Results indicate that sensitive units with severe erosion cover a vast area of central basin and a large volume of soil in this semi-desert area is sedimenting in Panzdah-e Khordad Dam reservoir. Finally, the article proposes some logical solutions to control and reduce erodibility of soil.