An Evaluation of the Parameters of Philip’s (1957) Infiltration Equation on Wetland Ecosystem in Agwagune Rural Catchment, Cross River State of Nigeria

Abstract

The parameters of sorptivity(S) and transmissivity (A) inherent in Philips (1957) infiltration equation are often employed to explain the effects of capillary action and that of gravity as water moves from the surface down the soil profile. The model was derived from diffusion theory as a basis for evaluating water holding capacity of soils beyond which fluvial processes of overland flow, runoff and erosion might be initiated on a given landuse. The study area is prone to ecological risks of flooding, water logging and landslide which calls for a proper geotechnical investigation with the need to proffering mitigation measures of sustainable land management. Infiltration data were gotten from rainy and dry seasons measurement in the field to establish mean values used for computation. The result obtained from the differentiated equation of di/dt showed negative (0) values after a period of 50 minutes which continued till a time interval of 180 minutes (3hrs). The plot of di/dt against ½√t gave a straight line graph whose slope value was less than 1 (0.05). This indicate, landuse soil with very low infiltration capacity since parameters(S) and (A) broke down easily upon wetting in less than one hour. Unsustainable land use practices as continues cultivation, wetland conversion for dry season farming, destruction of riparian vegetation among others should be avoided.

Keywords: Philip’s equation, sorptivity transmissivity, soil water holding capacity, fluvial processes