Physical and chemical characteristics of groundwater in south baris-el Kharga area as related to the prevailing different aquifer systems, western desert, Egypt

Abstract EN

The study area which is a real desert is, solely, depending on the groundwater as the only source of development, where neither surface water nor rainfalls are available.

This area is characterized by two different physical systems of groundwater occurrence; the unconfined condition in Bares oasis, where the water table is shallow and free, and the confined one in El Kharga oasis, where the water is under artesian pressure.

The total energy contained in each of the water systems depends on three components: pressure, velocity and elevation head and, hence, affects greatly the water characteristics in such system.

The present work is a trial to differentiate between the physical and chemical properties of groundwater exists under different conditions in the middle part of the western desert aiming to understand the relationship between groundwater occurrence and its quality.

In Bares oasis (unconfined aquifer system), data of 32 groundwater samples were collected and used to assess the water quality of the aquifer.

The analysis reveals that low dissolved oxygen (DO) values and high iron contents are detected.

Meanwhile, values of the oxidation-reduction (Eh) potential show that the groundwater is in a reduction condition.

The groundwater salinity shows a general trend of increase from northeast (El-Kharga) to southwest (Bares) with a fresh to slightly fresh water classes.

The study also indicates that the groundwater in the area is of mixed origin, possibly pure meteoric but occasionally affected by marine deposits.

Analyses of minor and trace constituents show that their concentrations are in the acceptable limits for different uses, except for higher iron and manganese concentrations.

In El-Kharga oasis (confined aquifer system), literatures show that the groundwater is characterized by lower pH, DO, salinity, iron and manganese contents but higher Eh and temperature as compared with the conditions in Bares oasis.