Hydrological study of a section of the Tigris River between Shirqat District and the Lower Zab Estuary using HEC.RAS program

Abstract

The study aims to identify the flood risks and the resulting effects of a section of the Tigris River between the Shirqat district and the mouth of the lower Zab using (HEC.RAS) due to the exposure of the study area to the floods of the Tigris River from time to time, which pose a great danger to the natural and human phenomena within the study area. On the data of water releases and their evaluation through hydrological data, and the analysis of the results of the (HEC.RAS) program for each cross-section and the study of natural characteristics, and the statement of the role of natural characteristics and their impact on the distribution of the amount of water running in the river spatially and temporally, and the amount of sediment carried in the river varies according to the variation of these factors From one site to another, analyzing the discharge patterns of the river channel, extracting flooding areas by digital modeling using the Hydrologic Engineering Center program, which is one of the most important river analysis programs and their applications, analyzing and modeling rivers and surface runoff, finding flooding maps and extracting the flood hydrograph in the river. As well as evaluating the river flow and the extent of the effect of high or low discharges in the river channel, studying the course changes for different periods of years (2010-2020) and analyzing the flood waves. It is clear through the flow hydrograph to determine the highest values for the inflow and outflow and for the duration of the flood wave, as the highest percentage of the inflow was (6875) m3 / sec. Critical areas have been identified such as areas of changing inclinations, changing the roughness coefficient and areas of expansion.