Iraqi National Journal of Earth Sciences

Abstract

A two-dimensional numerical based model is constructed to simulate the flow system of Dibdibba Sandy aquifer in Safwan-Zubair area, south of Iraq. A trial and error method is used to calibrate the model in two sequential stages: steady and transient states. Sensitivity analysis showed that the model is sensitive and less sensitive to change hydraulic conductivity and specific yield, respectively. The calibrated model is utilized to predict behavior of the aquifer over a planning horizon of 10 years (2001-2010) under two management alternatives. Based on the management alternative I which is depending on the fact that the operating wells is growing with a rate of 200 wells per year, a continuous decline of groundwater levels will occur if the model is run without recharging the aquifer. Average decline of head is of about (2 m). In the application of artificial recharge, the case is reversed. In most of the observation wells, the values of simulated head are rise and then decline gradually to a level that observed in the beginning of simulation period. The average rise in water table altitudes is (0.56 m). The results of the alternative II, which is depending on increase of discharge of each operating wells within the area of concern from 5 ℓ/s to 7 ℓ/s, are similar the first alternative where the averages decline and rise of water table altitudes are (0.85 and 0.88 m) respectively.