HYDROGEO.&HYDROCHEM.STUDY OF AL-NAJAF QUADRANGLE

Abstract

The exposed rocks in Al-Najaf Quadrangle are represented by: Dammam, Euphrates, Ghar, Nfayil, Injana, Zahra and Dibdibba formations, in addition to the Quaternary sediments, which cover about 25 % of the map area. From the structural point of view, the western part of Al-Najaf Quadrangle is located within the Southern Desert of Iraq, which belongs to the Stable Shelf of the Arabian Platform, while the eastern part is located within the Mesopotamian Zone of the Unstable Shelf. Topographically, the map area can be divided into two regions: Mesopotamia Plain and Desert Plain. The climate of the map area is under the conditions of arid climate, which is highly affected by desert condition. It is characterized by hot and dry summer and relatively cold winter with low rain fall. Injana, Euphrates, Dammam and Umm Er Radhuma formations represent the main aquifers within the map area, to the west and south of the Euphrates River. Injana Formation represents a local aquifer within the clastic sediments around Al-Najaf city. Dammam and Umm Er Radhuma formations represent the main first and second aquifers within the carbonate rocks, respectively. While Euphrates Formation represents a shallow local aquifer within the carbonate rocks especially along Euphrates River. Quaternary sediments of the Mesopotamia Plain represent the main aquifer within the northeastern part of the map area to the east of the Euphrates River. The general direction of the ground water flow in the western and southern parts of the map area is from west to east and from southwest to northeast, while in the Mesopotamia Plain; the ground water flow is from northwest toward southeast, with some local divergences. Within the Mesopotamia Plain, some areas are characterized by piezometric ridges following river courses and irrigation channels, on the other hand piezometric depressions occur in areas, of relatively low topography and far away from river courses, and irrigation channels. Quality of the ground water is variable. It is mainly sulphatic in the western and southern parts of the map area; to the west and south of the Euphrates River, with some chlorides water in local areas, while it is mainly chloridic in the Mesopotamia Plain, with sulphatic water, in local areas adjacent to rivers and irrigation channels. The ground water in the map area is classified according to the total dissolved solids into five classes: slightly brackish water, moderately brackish water, highly brackish water, salty water and brine. The ground water in the western and southern parts; to the west and south of the Euphrates River is mainly slightly or moderately brackish water. While in the Mesopotamia Plain, the ground water is of higher salinity than the western and southern parts. Mostly, the ground water in the map area is not suitable for human drinking, but it is mostly suitable for live stock, except in wells of high salinity. Also there are limitations with respect to poultry. Ground water at the western and southern parts of the map area, to the west and south of the Euphrates River can be used for irrigation purposes. But, the ground water in the Mesopotamia Plain can not be used for irrigation, except in areas adjacent to river courses and irrigation channels. Water from a number of wells can be used for building and construction and industrial purposes.