Hydrochemical Characteristic Of Surface Water And Ground Water In The AreaBetween Dar El-Salam And Akhmim, Eastern Fringes - Sohag Governorate, Egypt

摘要

Egypt can be classified as an arid climate with 95% of its area as desert. A narrow strip of fertile land exists along the main stem of River Nile and within a relatively small delta in the north. It became the base for economic and social life of one of the most distinguished ancient civilization where agriculture was the main human activity. The goal of the present work is to study the impact of land reclamation projects on the groundwater chemistry in Sohag governorate. The hydrochemical characteristics, genesis and formation of groundwater mineralization as well as evaluation of surface and groundwaters for drinking and irrigation uses are discussed. The study includes chemical analysis of fifty fife water samples (13 surface waters, 37 shallow and deep groundwaters tapping the Pleistocene aquifer and 5 wells representing Eocene aquifer) were collected in June 2011. Most of the groundwater samples of the Pleistocene and Eocene aquifers lie in the fresh zone, while the brackish and saline water are less pronounced. There is a general direction of increasing water salinity from the northeast toward southeast. The higher values of water salinity is strictly confined to southeast of Dar El-Salam locality due to the leaching and dissolution process of Pliocene, Eocene and soil layers in addition to hight salinity content of soil, high evaporation rates, over-pumping activity and the lack of drainage system in the reclaimed areas. This reflects the impact of land reclamation projects on the groundwaters. The relatively high values of boron in the groundwater of the Pleistocene aquifer compared with the surface waters indicate the pollution from the excessive irrigation water where the groundwater of both aquifers is unconfined types. Both aquifers and surface water nearly have the same concentration of phosphate, indicating the recharge from the surface water to groundwater of these aquifers. The high values of NO3 - for both aquifers relative to surface water are referred to the excess amount of nitrogen fertilizers used in this cultivated area as well as seepage of irrigation canals and drains. The ion ratios, ion dominance, hypothetical salts combinations, Piper geochemical evolution diagram, Stuyfzand classification and Statistical analysis confirm that the surface water and excess irrigation water are the main sources of recharge for both aquifers. The groundwater samples of both aquifers have the same chemical evolution, thus suggesting the hydraulic connection between the two aquifers that occurred through the faults plain. In brief, most of the surface and groundwater samples in the study area are suitable for drinking and irrigation.