Abstract
Seawater intrusion is examined on the two-layered unconfined aquifers. Numerical solutions obtained by Residual Flow Procedure show that Dupuit's approximation and Herzberg relation are hardly satisfied near the downstream end. With apprication of velocity shape factor, analytical solutions are derived on flow rate and on the shapes of free surface and fresh-saltwater interface. Analytical positions of fresh-saltwater interface agree with experimental position and numerical one. From the simuled results, it is clarified that seawater easily intrude to the two-layered aquifers in case that the layers in higher permeability overlie on the layers in lower permeability.
