NUMERICAL SIMULATION ON RAINFALL INFILTRATION FROM NON-UNIFORM SURFACE OF SLOPE AND SURFACE RUN-OFF PROCESSES

Abstract

 Rainfall infiltration and surface run-off processes has been researched for many years under the uniform field condition. In a real surface, however, hydraulic conductivity and other physical quantity have spatial variation, and it is considered that surface run-off occurs not only the bottom of the slope but other territory. In this study, a special distribution model of the hydraulic conductivity is used to generate aquifer with pseudo dispersion and bias, and surface run-off quantity and its composition in some patterns of rainfall, in three-dimensional field is evaluated by the numerical analysis. As a result, it was shown that surface run-off quantity in uniform field tend to evaluate less than the result of analysis in non-uniform field, and it was also shown that hydraulic conductivity and surface run-off ratio in heavy rain can be closely resembled by a logarithmic function.