Linking an interstorm model to a storm model

Abstract

A simple transpiration equation was used to develop a interstorm model using three important factors : atmospheric conditions, vegetation and soil moisture. A simple inter storm model was used to keep track of the most dominant moisture flux in semi-arid regions: transpiration. The temporal resolution of the model was one day. The soil mois ture changes due to rainfall were simulated using two types of rainfall - runoff models. The first model was a simple bucket model and second was a complicated model called KINEMA T. Both the models performed equally well because runoff forms a very small component of the entire water balance. The model was calibrated using Kendall'92 data and validated using Kendall'90 data. One of the inputs to the model was leaf area index (LAI) which was used as a vegetation component in the model. In semi-arid regions, LAI is strongly dependent on temperature and precipitation. This property was used as a way to find out the seasonal variability of LAI. It was observed that a seasonal variable LAI was found to produce better simlations than a constant value of LAI. .