Asian Journal of Research and Review in Agriculture

Siwa Oasis is illustrated by the produced Digital Elevation Model as a natural depression occupies an elongated depression east-west wards in the Western Desert of Egypt. This DEM realized that the descending slopes are mostly converged to the lowermost areas without outlet. Accordingly, Siwa Oasis is currently suffering from an excessive rise in the subsoil water table, high water salinity and high content of some trace elements resulting in land deterioration. Hydrochemical water resources based on the chemical analysis of sixty seven water samples collected from aquifer via wells, artesian from springs, ponded in artificial lakes, drainable from drainage network and logged as water table. The evolution of water resources based on water analyses for pH, EC, Soluble ions (Na⁺, Ca²⁺, Mg²⁺, K⁺ and Cl^-, SO₄^2-, HCO₃^- and CO₃^2-)^-and some trace elements (boron, aluminum, iron, cupper, manganese and Zinc). The results show that except for water springs, most of the water samples are severely saline with sodium and chloride toxicity. Water from wells, drainage water table and lakes are mostly having severe toxicity of boron. The contents of aluminum in all water samples are less than the recommended maximum concentration; however, manganese and cupper are mostly more than the recommended maximum concentration. Fe and Zn are relatively more than the recommended maximum concentration. Since the oasis is an isolated ecosystem, unconventional recommendations, measures and interventions are required to prevent or ameliorate the exacerbation of Siwa problems. It can be done by increasing soil depth over the water table by transporting sand from sand dune, utilizing crop tolerance to salinity and toxicity, changing method of irrigation in certain land units using the excess water for cultivating spatial types of grasses and trees in fixation of sand dune.