Prediction of Surface Runoff for Mosul Dam Reservoir from Different Regional Catchment Areas Using Arc SWAT Model

Abstract

Due to the lack of surface runoff data in that area, the Mosul dam reservoir watershed was modeled by using the Soil and Water Assessment Tool, which has an interface with the geographical information system (ArcGIS). This model was calibrated for the period extended from 1979–1991 with a monthly intervals and validated for the period from 1992–1999. A SUFI – 2 algorithm procedure within the SWAT- CUP program was applied in the calibration and validation process and sensitivity analysis. The accuracy of this model for the studied area was classified as very good for the calibration period and good for validation according to the statistical parameters. The results of the sensitivity analysis showed that there are eight parameters that have the greatest impact on the hydrological processes in the study area. Results illustrated that the area of the Mosul Dam watershed was 11108 km2. Results showed that the average annual net runoff that entered the Mosul dam reservoir was 2565 MCM. This represents 13.5% of the average annual total runoff volume. Due to the shortage of water during the dry seasons, this amount is more relevant. As a result, it is necessary to improve the groundwater reservoirs during the rainy seasons and reuse water, as well as increase the effectiveness of water distribution for all uses. Furthermore, the sub-basins in the Iraq region contribute 57.8% of that percentage, 38% of those in Turkey, and 4.2% from sub-basins in Syria.