Abstract
The present study indicates that the factors controlling the hydraulic relation between surface water and groundwater at the western lake shoreline change from one locality to another. This depends upon the lithological characteristics and the major structures. In the southern sectors, sedimentation at the bottom and sides of the lake prevents the water movement to the Nubian sandstone aquifer. The potentiometric map reveals that the water level altitudes range between 170 m in the vicinity of the lakeshore line and 110 m west of the lake. The groundwater flow lines show that the main recharge to the aquifer comes from the southwest direction, as well as from the lake inland to variable distances (about 30 Km). During the present study, Darcy's law was applied to calculate the recharge from the western shoreline of Lake Nasser to the adjacent Nubian aquifer. The maximum value of seepage was at Garf Hussein (27.71 x 10(6) mA(3)/year), which may be related to high permeability and hydraulic gradient. Also, it may be related to the N-S strike faults that cut the area on both sides of the Lake, and the groundwater is expected to have free circulation through the faults of this trend. The minimum value was recorded in Adindan section (0.61 x 10(6) mA(3)/year). This may be related to the limited recharge from the lake to the aquifer, due to the sedimentation that dislocates this recharge.