Distribution of pulse type uniform input in aquifers in tropical regions

Abstract

The present work presents mathematical models for the distribution of solute concentration of uniform input of pulse type along sinusoidally varying unsteady longitudinal velocity through such inhomogeneous aquifers of finite as well as semi-infinite extents whose main source of replenishment is infiltration during rains. A new time variable is introduced by using an expression in old time variable. Numerical solutions of such models are obtained using finite difference approximations. At initial stage the dispersion problem is considered steady one in homogeneous aquifer. Its solution is considered as initial condition for the respective unsteady problems. To achieve minimum time period of computation, the parameters of the problem are non-dimensionalized in terms of the existing variables in cases of semi-infinite and finite aquifers separately. The effects of inhomogeneity in both cases are shown through illustrations.