DEVELOPING A HYDRAULIC SIMULATION MODEL TO DETECT THE AGRICULTURAL LAND-USE SERVED BY IRRIGATION CHANNELS: A CASE STUDY AL-KHORA RIVERS, SOUTH OF IRAQ

This research aims to determine the areas and locations of agricultural lands served by irrigation water in the Al-Khora region, northwest of Basra city. As the irrigation water flows to the agricultural lands in the Al-Khora area through the irrigation channels branching from the Al-Saraji and Al-Khora rivers, which branch from the Shatt Al-Arab, and are designed to irrigate the surrounding agricultural lands depending on the tide’s phenomenon. Since tidal water level in the Shatt al-Arab is variable throughout the day, which leads to an irregular distribution of water between one region and another throughout the days of the year, and it is difficult to determine the areas served by irrigation water whenever we move away from the Shatt al-Arab. Therefore, this study focused on building a hydraulic simulation model in the HEC-RAS program to simulate flow in the rivers of the study area and to know the extent of its spread in the surrounding areas. The areas of agricultural uses reached by the tidal water were determined in the periods of the lowest tide in November, and the volumes of water used in the irrigation process and the ranges of their impact on the neighboring areas were also calculated. The study concluded that the agricultural areas confined between the Sarraji and Al-Khora rivers can increase from 1298 to 1698 acres (equivalent to 31% of their original area) if the areas of land that can be irrigated by the side canals branching from the two rivers are taken into consideration.