The middle part of El-Qaa Plain is one of the few promising areas in Sinai Peninsula looked after for the possible integrated development, based mainly on local groundwater resources. The main objective of the present study is to recognize in detail the characteristics of the Quaternary aquifer. To fulfil this objective, a geoelectrical study has been carried out through 39 Vertical Electrical Soundings with the purpose of recognizing the geometry and characteristics of the Quaternary aquifer. Besides, construction of depth to water, water level and salinity maps and re-evaluations of pumping test data of selected wells were also carried out.
Through the qualitative and quantitative interpretation of the sounding curves it was revealed that the aquifer extends in the whole area at a depth of 3-65m below the ground surface. The aquifer was found to consist of two parts. The upper part consists of sand and gravel saturated with fresh water with a thickness of 30-86 m. This part is characterized with a resistivity range of 2-82 Ohm.m. The lower part consists of sand and gravel with clay intercalation having a resistivity of 1-23 Ohm.m, which refers to water of less quality than that of the upper part. The lower part is much thicker than the upper part and extends downward beyond the maximum depth of investigation reached during the geoelectrical survey. However, within that depth the explored thickness of the lower part is not less than 50 m. The interpretation also indicated that the water-bearing formation is overlain to the surface by a dry sedimentary succession of a much higher resistivity and variable thickness.
The hydrogeological studies revealed that high water level (22m) is recorded east of the study area and the lower one |
