Numerical Modeling of Drainage Schemes in Layered Formations: A Kuwait City Case Study

A computer modeling technique is developed to simulate ground water drainage considering a heterogeneous, discontinuous, layered formation with pumping wells screened in several layers and drawdown‐induced recharge/discharge under complex urban hydrological conditions. A composite finite‐difference mesh is used to simulate both the more distant areas (coarse mesh) and the actual drainage site (fine mesh). The skin loss parameters of screens are involved to control the aquifer yield. A pilot drainage scheme is being operated in Kuwait City to eliminate the harmful effects of water table elevation. The scheme involves six multiscreened pumping wells and numerous observation wells. Calibration through computer simulation indicated that the transmissivity exhibits relatively little areal variation, whereas the leakance of partially cemented silty beds and lenses fluctuates significantly over the study area. This heterogeneity effect as well as the induced recharge from various man‐made sources have considerable impact on the drainage efficiency. Skin loss parameters of pumping wells affect the amplitude of drawdown in different aquifer units.