Three-dimensional numerical simulation of impacts of urbanization on groundwater flow and salt transport in a coastal aquifer system, Busan, Republic of Korea

A series of three-dimensional numerical simulations using a generalized multidimensional hydrodynamic dispersion numerical model was performed to simulate effectively and to evaluate quantitatively the impacts of urbanization on density-dependent groundwater flow and salt transport in a coastal aquifer system, Busan, Republic of Korea. A series of steady-state numerical simulations of groundwater flow and salt transport before urbanization with material properties of the geological media, which were established by model calibration considering all the urbanization factors, is performed first. A series of transient-state numerical simulations of groundwater flow and salt transport after urbanization is then performed considering the urbanization factors separately and all together. The results of the numerical simulations show that density-dependent groundwater flow, salt transport and seawater intrusion patterns in the coastal aquifer system are intensively and extensively impacted by the urbanization factors. However, such impacts of each urbanization factor are not spatially uniform but locally different.