ABSTRACT
The present work tried to estimate the runoff discharge and groundwater recharge
volumes for the catchments of Ras Gharib area using the Soil Conservation
Service curve number (SCS-curve number) and the water balance methods.
The two methods were selected among other methods used by hydrologists
due to simplicity and popularity for application in arid and semi-arid
areas like Egypt. The watershed delineation and streamlines for Ras Gharib
region have been accomplished using ArcMap 10 GIS and the 1-arc second
DEM which demonstrated three basins in the study area. The rainfall data
points nearby the study area, extracted from the TRMM data, have been used
as input for the Log-Pearson III distribution in order to calculate the design
storm for different return periods (100, 50, 25, and 10 years). The results of
applying the SCS model estimated the runoff depths as 19.86, 8.00, 2.32, and
0.06 mm for the different return periods, respectively. The total surface runoff
volumes reached the study area are 34.78, 14.02, 4.07, and 0.11 Mm3, respectively
for the selected return periods, whereas the total groundwater recharge
volumes for the selected storm return periods are 58.16, 31.34, 18.14,
3.18 Mm3, respectively.