ABSTRACT
Infiltration is one of the major components of the hydrologic cycles. In watershed management, prediction of flooding, erosion, and pollutant transport all depend on the rate of runoff that is directly affected by the rate of infiltration. This chapter describes the soil and conservation engineering by providing the Soil Conservation Service Curve Number Method (SCS-CN) infiltration approach in approximate physical based hydrological model to be used for the river catchment in Malaysia and each antecedent water condition. It provides a framework for infiltration issues in the hydrological modelling. The chapter discusses some basic classification of the infiltration model approaches. This is important for the researcher to embed the infiltration data in the range of hydrological modelling. Equations that are physically based approximations use parameters that can be obtained from soil water properties and do not require measured infiltration data. If the precipitation rate exceeds the infiltration rate, a runoff will usually occur unless there is some physical barrier.
