Effect of surface water system on groundwater composition using geochemical modeling and geostatistical techniques, East Nile Delta (Case study)

El Gabal Al Asfar and El Adelya areas are parts of the East Nile Delta; where development is constrained by the amount of good groundwater quality that can be withdrawal sustainably. In these two areas, the Quaternary aquifer represents the main source for groundwater; where seepage from Nile drainages and irrigation canals consider the main recharge sources. Unfortunately; the groundwater in such aquifer has been heavily polluted by heavy metals and biological activity due to seepage from sewage and agricultural drains. Geochemical modeling (NETPATH) determined the sources, mixing and delineates the recharge areas within the Quaternary aquifer. The results showed that the groundwater salinity is controlled by dissolution of minerals and salts in the aquifers matrix along flow paths and mixing of chemically different waters. The geochemical model output shows high potential recharge for the Quaternary aquifer at El Gabal Al Asfar area along the drains. The surface water-groundwater interactions have been evaluated; where the maximum mixing percent ratio attains 79% from surface water to 21% from groundwater. To effectively manage groundwater in El Gabal Al Asfar area, Future groundwater pumping must be closely monitored to limit these effects. R-mode factor have been calculated for twenty variables. The results show that; five principal factors were obtained in El Gabal Al Asfar area and four principal factors were obtained in El Adelya area. Finally hierarchical clusters were constructed; most of the groundwater samples are clustered around the surface water samples confirming the effect of surface water system on the groundwater composition.