GEOCHEMICAL MODELING OF GROUNDWATER IN THE DAMMAM FORMATION SOUTH OF RAZZAZA LAKE, MIDDLE OF IRAQ

Abstract

The study area is located at 25 Km west of Karbala city covering an area of about 640.57 Km2. The Dammam, Euphrates, Nfayil, Fat'ha, Injana and Dibdibba
formations are cropped out and coverd in some areas by recent Quaternary deposits. The study area is considered as a part of Western Desert (205000 Km2) and the hydrogeological unit produced in the area is Dammam ormation, which receives its recharge from its exposure at south western region. The general direction of groundwater flow is from west and south west towards east and north east. The groundwater is generally alkaline in nature with pH median ranging from 7.03 to 7.81. The TDS values range from 1693 to 1852 ppm and EC values range from 2410 to calcite, dolomite, exchange and halite). The first reaction path/1 located in the south part of the study area toward northeast, and the second reaction path/2 located in the southwest towards northeast, where path/1 is precipitated Gypsum, Dolomite and Exchange between Na/ Ca, while Calcite and Halite (NaCl) are dissolved along the flow path down gradient. The second path/2 is Calcite and Exchange between Na/ Ca, while Gypsum, Dolomite and Halite (NaCl) are dissolved along the flow path down gradient towards Razzaza Lake basin.