Simulation of Rainfall-Runoff in the Diyala River Basin in Iraq using Hydrological Model by HMS with remote sensing, Geo-HMS and ArcGIS

Abstract

In Iraq, the Diyala River (DR) occasionally experiences both droughts and floods. The DR is supplying the amount of water to Tigris River at the south of Baghdad. Estimation of runoff from precipitation is very important because of its impact on decision-making in water resources management. The conceptual and distributed hydrological model was adopted and by HEC-HMS, Geo-HMS, and GIS software, remote digital elevation models were processed. The sensitivity, calibration, and validation were made through the period 2017-2021. The estimated CN values were from 60 to 100 with distributed related ratios between 0.6% to 52.8%. The differences between the observed and estimated inlet discharge of Hemrin Dam were for (+0.1 to -0.2) % with some more at peak discharge point. The HEC-HMS, using data from NASA and FAO, was acceptable model. The results with an accuracy of 95%, which is indicated by the value of R2 and PBIAS indicators.