Hydrologic and Hydraulic Modelling of the Greater Zab River-Basin for an Effective Management of Water Resources in the Kurdistan Region of Iraq Using DEM and Raster Images

Abstract

The Greater Zab river-basin is one of the most important catchment areas in the Kurdistan region amongst the other four catchments which are; Lesser Zab, Sirwan, Khabur, and Uzem. Thus, this research paper seeks to enhance hydrologic information systems in the region under study via advanced technologies such as geographical information systems and hydrologic and hydraulic modelling system using remotely sensed data such as digital elevation models and satellite images. These techniques provide powerful and cost-effective tools for managing water resources and enable hydrologists and researchers to handle up-to-date hydrologic and hydraulic data and information. In this study, geomorphological analysis of the Greater Zab River-Basin has been performed by using digital elevation model and the obtained results are compared with that already obtained from the digitizing process. Computational hydrologic and hydraulic modelling systems are designed using interface method which links GIS with the modelling systems (HEC-HMS and HEC-RAS). Floodplain analysis of the Greater Zab River has been presented. Hydraulic model has been validated based on the obtained hydrograph from the Khabat flow gauge station which is located at the lower reach of the Greater Zab River. The comparison between the gauge station measurements (average discharge 750 m3/s and pick discharge 1,500 m3/s) and the results that obtained from the hydraulic model (707.92 m3/s and pick discharge 1415.18 m3/s) shows good agreement between both results.