Field Evaluation of the Effect of Watershed Management Operations and Water Resources Sustainable Management on Reducing Erosion and Sediment from Floods

Nowadays, given the human need for water, efforts to reach sustainable water resources are essential and important. The purpose of this study was to investigate the effect of water structures construction on the conservation and optimal management of water resources in Nashar basin. For this purpose, by field survey, the specifications of the construction structures and information on water resources in the area, including wells, springs and qanats, were collected. Information on water resources was obtained from the Hamedan Regional Water Department before the construction of the structures. The results showed that 856 small water structures were constructed in the watershed, of which 660 were mortar-clad inland structures, 4 were inland-china structures and 192 were gabion structures. The volume of reservoirs created by the implementation of these structures is equal to 50936 cubic meters, of which 29502 cubic meters have been filled and the empty volume that can currently reduce floods is 2143434 cubic meters. The total discharge of the three springs control watershed before the construction of the structures was 1.8 liters per second, which after construction has reached 2.15 liters per second. The average water height of wells in the region has decreased from 11 meters before ground construction to 9 meters after construction. Also, the total discharge of active qanats in the area before construction was 32.5 liters per second, which has reached 38.5 liters per second after construction. Therefore, the impact of the construction of water structures is positive and has led to an increase in water resources in the region.