THE MOVEMENT OF SAND DUNES AND ITS EFFECTS ON WATER CHANNELS IN THE PROJECT OF SOUTH VALLEY

Abstract

The project of the Development of south valley in Toshka region is one of the huge projects in Egypt. the project consists of Pump station with maximum static lift 52.50 meters , sheikh Zayed canal, Conductor of branches 1 and 2, Branch 1, Branch 2, conductor of branches 3 and 4,Branch 3, Branch 4. Toshka project located in a desert area where sand dunes spread making it an exhibition on a permanent basis to sand, sand falls into water channels with its load in addition to low water velocity most of the year, the intensity of the brightness of the sun for a long periods reach to 11 hour per day and low water depth in many reaches, all these factors make an ideal environment for the growth and spread of weeds in water. The weed growth in the water channels makes it otherwise trap to catch the sand resulted from the movement of sand dunes thus leading to effect on the hydraulic efficiency of water channels. Methodology of this study containg the following procedures, making analysis of satellite images for reaches of sheikh zayed canal,estimation of accumulative sand quantities that falls annually in sand collectors on the sides of the main canal and its branches, survey 8 cross-sections in the main canal, study water quality by collecting 18 water and soil samples from the main canal and its branches, making the mathematical model by using SOBEK program to determine the hydraulic efficiency of the main canal. The reaches that suffer from movement of sand dunes in the main canal are 12 reaches from kilometer 24.750 to kilometer 43 with different lengths. Based on the accumulative quantities of sand in sand collectors, It turns out that the quantities expected to fall in the main canal is 4468