Water and sediment yield estimation: A case study in Bawashaswar Watershed/ Iraqi Kurdistan Region

Abstract

Water flow in the seasonal streams forms a vital supplier of water resources, particularly in arid and semiarid areas due to its high-water supply from the precipitation during the wet season. This research aims to estimate water and sediment yield in the Bawashaswar watershed, which is far ~90 km from Kirkuk City. It has a semiarid climate and covers an area of 277 km2. The Bawashaswar Dam was constructed —for multi-purposes such as drinking, irrigation, livestock, and tourism— at the outlet of the watershed north of Kifri town. This study aims to give valuable data and information about water and sediment yield within the watershed of the Bawashaswar Dam and the possibility of the investment of the water for the above purposes. The Soil Water Assessment Tool (SWAT) was integrated with several datasets (such as satellite images, Digital Elevation Model (DEM), land use, land cover, curve number (CN), daily climatic data of temperature, precipitation, and digital soil map) to achieve the results. The estimated results include precipitation, evaporation- transpiration, percolation, surface runoff, water yield, loss of transport, and sediment yield. The results showed that almost all the siltation (>0.5 ton/ha) comes from the western and northern parts of the Bawashaswar Watershed due to the high topographic relief and the high channel discharge there. These results will support the future development plans and management of the watershed through mitigating and minimizing the size of the ground surface degradation problems all over the study area with increasing the lifespan of the Bawashaswar Dam.