A simple soil water balance model to estimate groundwater recharge in the dry zone of Sri Lanka

Abstract

Estimating the rate of recharge is essential in developing the ground water resource. The soil water balance of the root zone is a simple method of estimating recharge. This paper analyses the important components of a soil water balance and determines the essential components of the water balance equation for the dry zone of Sri Lanka to estimate recharge. From the data presented in this paper it is shown that the processes of rainfall interception, surface runoff and preferential flow are all important processes in the hydrological cycle for the dry zone. A simple model thus formed is verified with data from studies in the dry zone of Sri Lanka as well as from other parts of the world.