Hydrogeological characteristics of Dammam confined aquifer, West Razzaza Lake, Iraq

Abstract

The Rahhalia to Ekhedhur area to the west of the Razzaza Lake in central Iraq is chosen due to its distinguished hydrogeological nature through the existing systems of the faults. The Dammam Formation confined aquifer is one of the important basins of groundwater in Iraqi western desert. The flow map of Dammam basin shows the groundwater flow from the west of the basin, towards Razzaza Lake to the east. The objectives of the current research are to define the hydraulic properties for the Dammam Basin, west Razzaza Lake. Recovery and Pumping experiments for three wells distributed in the area were evaluated to determine the hydraulic properties. The values of Transmissivity (T), Hydraulic conductivity (k), and Specific capacity (SC) are ranged from (392 to 600.25 m2/day), (13.06 to 20.0 m/day), and (88.61 to 215.1 m2/day), respectively. Highest transmissivity value was found in well W 2, while low values were found in well W 1. Most of the weak zones (fractures, joints, and bedding planes) composed of carbonate rocks that are very soluble. The variations of hydraulic characteristics of the aquifer depend on the inhomogeneity of the Dammam basin that shows differences within the studied area. As well as, these variations of values are due to the type of Dammam aquifer, which is a karst confined aquifer.