Hydrogeology of the western part of the Iraqi ًWestern Desert

Abstract EN

The western part of the Iraqi Western Desert is covered by carbonates, clastics and marl.

The main aquifers in the region are within Suffi, Ga'ara, Mulussa, Muhaiwir, Ms'ad, Tayarat, Digma and Akashat formations.

However, Nahr Umr, Rutbah and Ratga formations were either not recognized or not announced yet in the involved areas.

Ga'ara aquifer is considered the most important one, on a regional scale due to its wide extent and large content of water.

Most aquifers are recharged from rainfall and runoff of the intermittent wadis in form of leakage losses through permeable strata, fractures, fissures, joints and cavities into shallow aquifers.

It is assumed that a hydraulic connection between aquifers exists to some extent.

Leakage of water is either downwards or upwards, depending on piezometric relation of aquifers, lithology, structure and extent of water-bearing horizons.

The available updated hydrogeological information in the Hydrogeological Data Base indicates the presence of a water divide within the studied area, to the west of Rutbah town, with a general North – South trend.

This water divide causes the groundwater to flow into opposite directions along its trend; accordingly, the general direction of the groundwater within the eastern part is towards east and northeast mainly, following the discharge zone along the right bank of the Euphrates River.

While, at the western part of the studied area, the direction of the groundwater flow is towards the west; beyond the Iraqi borders.

Locally, different directions of flow occur throughout the region, depending on the geological setting of water-bearing horizons and the nature of structure and topography.

All the available previous studies have not mentioned the presence of this water divide within this part of the Western Desert, and always have, generally suggested that the direction of the groundwater flow is towards the east and northeast.

Salinity of the groundwater increases with depth and also towards discharge zones in general, but it ranges mainly from fresh to slightly brackish within the studied area.

Water type varies and includes bicarbonate, chloridic and sulphatic water.