HYDROGEOLOGICAL CONDITIONS&GROUND-WATER USE IN DIYALA GOVERNORATE.

Abstract

Diyala Governorate is located at the eastern part of central Iraq. It is considered as a part of the Unstable Shelf, which includes three structural zones: the High Folded and Low Folded Zones which represent the northern and eastern parts and the Mesopotamia Zone, which represents the southern and southwestern parts of the governorate. The high areas are composed mainly of a series of anticlinal structures with cropsout of sedimentary rocks. The exposed rocks range in age between Lower Cretaceous and Pliocene, and Quaternary sediments. The climate of the governorate is arid to semi-arid which is characterized by relatively cold winter with low to moderate rainfall with hot and dry summer. The Pliocene and Pleistocene rocks, which belong to Bai Hassan and Mukdadiya formations represent the main aquifer in the most parts of the governorate, especially within the Folded Zones, while the Quaternary sediments represent the main aquifer within the Mesopotamia Plain and also in different other locations, where they are of reliable thickness and suitable for storage water. The general direction of the ground water flow is from northeast towards southwest, it is in accordance with the topography of the area. The high regions of the governorate represent the recharge zones while the Mesopotamia Plain represents the discharge zones. Ground water quality is variable; it is mainly sulphatic with bicarbonate water in the northern and northeastern parts of the governorate and with chloridic water within the Mesopotamia Plain, in general. The ground water is classified according to total dissolved solids (salinity) into six classes: fresh water, slightly brackish water, brackish water (two sub classes: moderately saline and saline), salty water and brine. Low salinity water is found mainly within the northern and northeastern parts of the governorate, in general, while high salinity water is found mainly within the Mesopotamia Plain at the southern part of the governorate. The water of 30% of the wells is suitable and can be used for human drinking, while the water of most of the wells can be used and suitable for animal drinking and agricultural purposes, when recent technology is applied in agriculture and irrigation and select the most suitable species of high agricultural products. The water of about 45% of the wells is suitable for chemical industries, 37% suitable for petroleum industries, 20% are suitable for cement industry and 11% suitable for food industries, while the water of all wells is not suitable for paper industry due to high content of calcium, and only 46% are suitable for construction and building purposes due to high content of bicarbonate. However, after treatment most of the wells can be used for these purposes.