Hydrology of Wadi Al-Arjawi Basin West of Lake Razzaza

Abstract

Hydrology is a branch of physical geography. This branch specializes in the study of water, whether surface water or groundwater. The current research  studied the surface water of the Al-Arjawi basin in terms of the amount of precipitation, infiltration, evaporation and surface runoff in the basin. Given the nature of the basin and its water resources, which include sudden torrents, the research was concerned with discovering the water collection areas and working to reserve the accumulated quantities of water provided by these torrents. Conservation large quantities of fresh water in arid regions is by adopting water harvesting methods whose success in storing water depends on the accuracy of calculating the probability of flooding and the expected amounts of rain, in addition to the amount of various losses, such as those that cannot be recovered, such as evaporation losses, or that can be used to feed the aquifer, such as leakage losses.  The great importance of developing multiple models to simplify the movement of water has emerged. Especially with the difficulty and high costs of providing realistic data and measurements associated with the phenomenon of sudden torrents, which are often sudden, whether in terms of space or time. The main objective of these models is to estimate the surface runoff of water, and the results of these models are useful in the optimal design of water harvesting methods that depend mainly on water collection areas. The research revealed the volume of surface runoff based on the application of the (Soil Conservation Service (scs-cn) model, as the highest volume of surface runoff was (4.72) m3 at a rainfall intensity of (27.6) mm, as the spatial suitability of the basin was studied within the variables that affect The application of water harvesting methods has been divided into three degrees of suitability represented in the first degree; which is weak and limited in the application of water harvesting methods. The medium degree of suitability and the third  degree of suitability, which is one of the best degrees of spatial suitability for the application of water harvesting methods. The basin included (10) groups for each group of sites that differ according to the spatial suitability of the topographical, hydrological, structural, geological and soil variables, as the highest area of ​​the seventh group reached about (685.4). km 2, of the total basin, which includes about (137) proposed sites for the application of water harvesting methods.