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Abstract
The Quaternary aquifer in the studied area is the main source of the groundwater. Excessive pumping from a coastal aquifer causes water salinization. Most of wells became unemployed, especially in the northern part of the studied area. Furthermore, farmers use drainage water as standby for irrigation, hence affects badly on the groundwater quality.
Therefore, Development of Effective Management Practices (EMP) to preserve water quality has become a must. Hence, this thesis aimed primarily to re-evaluate the quality of the Quaternary aquifer in the eastern Nile Delta region due to landuse and anthropogenic practices. Addressing the possible salinization sources of the aquifer as well as pollution sources’ tracking using Nitrogen-15 and Carbon-13 isotopic techniques was the second aim.
The study area lies east of the Nile Delta and extends between longitudes 31o 30\ 00\\ and 32o 6\ 00\\ east and latitudes 30o 30\ 00\\ and 31o 31\ 48\\ north. The obtained results show the salinity of the groundwater was increasing from south to the north and classified into three groups. The first group presents in the south of the study area and has 54 % of ground samples as fresh water. The second group presents in the middle sector of the study area and has 24 % of groundwater samples and the increase of salinity could be attributed to dissolution and leaching of soil during irrigation processes. The third group presents in the northern part of the studied area and has 22% of groundwater samples. The high salinity of this group may be attributed to salt water intrusion.
Environmental isotopes (2H, 18O, 13C and 14C) are analyzed to highlight on the origin and rechargability of the aquifer. The groundwater may be formed by mixing between recent Nile and old Nile water. Wells show enriched δ18O and δD values of the groundwater aquifer could be suffered from severe evaporation due to extensive irrigation. The depletion of the isotopic composition may be due to mixing with depleted water of the old Nile water. The relation between TDS and δ18O ‰ shows dissolution processes with the northern part samples.