Solutes are assumed to transport from putting boundary(soil surface) to solute front boundary in order to find the solution of solute front ad vance with time for a semi-infinite porous media column or corresponding field soil conditions. Convection-dispersion equation(CDE)

subjected to two bounda ry conditions both at soil surface (or inlet boundary) and at solute front i s solved analytically by using Laplace transformation method. The results of com parison between the analytical solution and the exact solution (in semi-infini te domain) show that the analytical solution is in good agreement with the solut ion in the range from putting boundary(soil surface)to the solute front. An im portant application of the advance of solute front is to estimate the transport parameters of solute movement through porous media under both laboratory and fie ld conditions. This leads to a new method for estimating parameters of solute tr ansport in soils. The new method requires observation of the advance of solute f ront with time. This can be done visually by using a tracer solution with dye in it. It can also be easily measured by using time domain reflectometry (TDR). Th e new method is simple

time saving

and is applicable to both laboratory soil co lumn and field soils.