Calculating the Water Balance for Kubaisa Basin by Simulating the SWAT Model, Western Iraqi Desert

Abstract

This study aims to calculate the water balance of the Kubaisa Basin in the Western Iraqi Desert using the SWAT model. The study is based on simulating water discharges and the factors affecting them over several years (1990-2023). The geographical, climatic, and hydrological data were collected to run the model. The research results indicate that water distribution in the Kubaisa Basin was estimated during the studied period, including the quantities of surface water, groundwater, and discharges. Climatic results for the Kubaisa Basin indicated an increase in the trend line for total rainfall, temperature, humidity as a relative, and solar radiation, while the trend line retreated for wind speed for the same period. The results of the hydrological components of the basin, which were shown by the SWAT model, namely rainfall (RN-P), surface runoff (SR-Q), flow as lateral (LT-Q), flow as groundwater (GW-F), evapotranspiration as actual (ET), evapotranspiration as potential (PET), water-yield (WLD), and water that permeates past (percolates) the root zone (PEC) which are considered the main elements of the water balance, had values of 79.72mm, 3.10mm, 0.02182mm, 0.0028mm, 76.47mm, 1742.16mm, 3.12mm, and 0.00mm, respectively. This research makes important contributions to the understanding and management of water resources in the Kubaisa Basin and the Western Iraqi Desert regions and can be a basis for future research in the field of improving water sustainability in these regions.