Infiltration Modelling in A Micro-Watershed of Dal Catchment

Abstract

Infiltration process is one of the most natural phenomena which plays significant role in engineering problems. Prediction of soil infiltration is a major problem due to its variability and proper selection of the technique used to determine the parameters of the models which depend on the local soil characteristics. The present study was carried out in a micro-watershed of Dal catchment, Srinagar, J&K state, India. The GIS (Geographic Information System) software was used to delineate the boundary of watershed and based on land use several observation points were selected to predict the infiltration rate under different land covers i.e. agriculture field, built-up land, orchard field and to compare validity of different infiltration equations viz. Horton, Philip and Kostiakov. The data on the infiltration of soil from the study area was generated through field measurements using double ring infiltrometer for post monsoon season with existing land covers and least square method of curve fitting were employed for determination of model parameters. In addition to this pedotransfer functions(PTF's) were employed to evaluate the parameters of Philip's infiltration model and compared with those of graphical method. Before conducting the field infiltration tests, the data regarding different soil properties like bulk density, moisture content, soil texture, hydraulic conductivity and organic matter were determined which effects the soil infiltration process and required for estimation of PTF's for the Philip's model. Statistical analysis was carried out between observed and evaluated infiltration rates in order to check the performance of these models.