MATHEMATICAL - MODELLING OF INFILTRATION CHARACTERISTICS THROUGH SOIL

Abstract

A multitude of infiltration models are in use in applied hydrology and science. Some of these models are theoretically based (Dooge 1973; Philip 1957; 1969; Green and Ampt 1911), while others are empirical (Kostiakov 1932; Horton 1938; Holtan 1961; Overton 1964). Some of the empirical models are quite popular and frequently . used in various water resources applications.. The reason for their popularity is that they are simple and yield satisfactory results in some cases. Since the empirical models are more or less based on experimental observations, they represent the overall infiltration process. The infiltration process can be represented by a systems approach, which uses an absorber or a network of absorbers. Infiltration constitutes input to the absorber. An absorber can be defined by a relation between its moisture content and the rate of infiltration to it. A generalized infiltration model has been developed by- Singh and Yu (1990) of which many of the existing models are special cases. The model uses a total of five parameters. Two of them i.e. basic infiltration rate and initial soil storage space, are physically based and can therefore be estimated from the knowledge of soil, properties, antecedent soil moisture conditions and infiltration measurements; the remaining three can be determined using the least . squares method...