Future visions for the integrated water resources management for old cultivated areas of Siwa Oasis, Western Desert, Egypt.

Abstract EN

The present paper predicts the deterioration and water logging in the old cultivated area due to the random future reclamation projects in the south.

This prediction is based on applying mathematical model for planning and managing this locality (Aquifer Simulation Model–ASM-in groundwater flow and solutetransport in two spatial dimensions).

The solution of the flow equation is based on the finite difference method.

The input data to the model includes basic and field items.

Basic data comprises the dimensions, boundaries and hydraulic properties (permeability and storativity) of the water bearing sediments.

Field data include surface and groundwater levels, boundary fluxes and pumping operations.

The model was calibrated in steady-state condition with nil factor between the input and output items of the water balance in the modeled area (the difference input /output was in the order of 9.3x10 - 5 m3/sec).

Among several scenarios, three water management scenarios were predicted after about 3 years with different conditions.

The first scenario keeps the present discharge from the natural springs and flowing wells with no change (620 springs and wells with total discharge of 7634 m3/h).

The results showed an increase in soil water with 0.94 m3/sec, which means rising in soil water table and more deterioration.

The second proposed scenario was ambitious by decreasing the total discharge by 29 % via controlling 120 flowing wells.

The results showed a decrease in soil water with 2.8 m3/sec during 1000 day, which confirms with the field investigation.

The third scenario was the predicted case due to reclamation activities of 10000 Fed.

with new wells of total discharge 1.49 m3/sec.

The model showed that the old cultivated area will receive an excess water of 0.62 m3/sec causing a rise in soil water level.

The study recommended that any reclamation activities must depend on the reuse of drainage water.

The digging of any new wells must not be allowed, especially in the southern parts.