A resistivity survey was conducted in the Nile Delta area to delineate ground‐water contamination caused by an improper sewage and irrigation drainage system, leaching from old lagoonal deposits, and salt‐water intrusion. Existing monitoring wells were used to measure the horizontal and vertical variations in water salinity. Vertical electrical sounding (VES) data for sounding points located near monitoring wells, together with the water salinity data of these wells, were used to obtain an empirical relationship between the inferred earth resistivity and the amount of total dissolved solids. This relationship was used together with the constructed apparent resistivity depth and geoelectric longitudinal sections to identify three zones of water‐bearing formation (fresh‐, brackish‐, and salt‐water zones). Along the studied profile, depth to the fresh‐brackish interface exceeds 150 m at Tanta City and decreases northward to 40 m or less between Qutor and Kafr El‐Sheikh. Depth to the brackish‐saline interface exceeds 180 m south of Kafr‐El‐Sheikh and decreases northward to 70 m near Hadadi village.

No abstract

No abstract

The Wadi Watir delta in the Wadi Watir watershed is a tourist area in the arid southeastern part of the Sinai Peninsula, Egypt, where development and growth of the community on the delta are constrained by the amount of groundwater that can be withdrawn sustainably. To effectively manage groundwater resources in the Wadi Watir delta, the origin of groundwater recharge, groundwater age, and changes in groundwater chemistry in the watershed needs to be understood. Mineral identification, rock chemistry, water chemistry, and the isotopes of hydrogen, oxygen, and carbon in groundwater were used to identify the sources, mixing, and ages of groundwater in the watershed and the chemical evolution of groundwater as it flows from the upland areas in the watershed to the developed areas at the Wadi Watir delta. Groundwater in the Wadi Watir watershed is primarily from recent recharge while groundwater salinity is controlled by mixing of chemically different waters and dissolution of minerals and salts in the aquifers. The El Shiekh Attia and Wadi El Ain areas in the upper Wadi Watir watershed have different recharge sources, either from recharge from other areas or from different storm events. The downgradient Main Channel area receives groundwater flow primarily from the El Shiekh Attia area. Groundwater in the Main Channel area is the primary source of groundwater supplying the aquifers of the Wadi Watir delta.

The over exploitation represents the main problem of sustainable development of the groundwater aquifer in the study area, large drop in groundwater heads was recorded, it reached from 70 to 80 m, the main trend of water flow was also disturbed and many depleted closed areas were appeared. Groundwater quality shows relatively high salinity contents of some groundwater samples and abnormal concentration of iron element which was ranging from 2 to 10 mg/l produces rust-colored deposits and a brown slime that builds up on well screens, pipes, and plumbing fixtures. The dominant water type is sodium bicarbonate followed by sodium sulfate and sodium chloride. For proper development and optimal utilization of such non-renewable resources, daily groundwater exploitation should be decreased; the minimum spacing between wells should not be less than 2 km and total depth of wells should be between 600 and 700 m. Moreover, the present flood irrigation system should be replaced by more developed drip, sprinkle irrigation methods and less water consume crops should be recommended.