Using Remote Sensing Techniques and Hydrological Models in Analyzing Water Drainage Systems Affecting Al-Kharj Governorate

Abstract

The research investigates water drainage systems and identifying the flooding area in Al-Kharj, which is the confluence of the valleys of Hanifa, Al-Sulay, Al-Hannaya, Nasah, Al-Haytham, Al-Aqimi, and then Al-Sahba, with a total area 111,491km2, which may cause risks on the natural and human environment in Al-Kharj, whether through water accumulation and stagnation in Low-lying areas and the resulting environmental hazards, or as a result of their inundation on urban areas, causing destructive effects on lives and property.The methodology is based on analyzing the drainage systems affecting the city of Al-Kharj, which is product by many steps and multiple inputs that include the elements of the stage before the surface runoff occurred and then the stage during the runoff, where collecting the largest number of elements affecting each stage and the Methods of evaluation it, then counted and analyzed them to create a topographical and hydrologic model of the drainage systems and analyzed the expected rain condition at different recurring times, especially 100 years. The morphological analysis of the basins, comparing the results of the outputs of the (DEM), tracking the paths of the valleys through topographic maps, satellite visuals, and the field study revealed that there is a mismatch between the outputs due to the interruption of the valleys flow, either for natural or human reasons, as it actually affects only 8 basins with an area 16266.7km2, Hanifa basin consider the most nourished with a water volume 124.6million m3 and a discharge rate of 756.4m3/s.