TR(BR)-137 : Development of model for simulation of flows of non-monsoon season

Abstract

In planning and design of water resources development schemes, reliable estimates of available water at the site of interest are required. For this purpose a long term stream flow data may be needed. It is generally observed that the desired stream flow data for long term period are lacking. Therefore, application of rainfall runoff model is useful to simulate flows and to have the accountability of soil water deficit during few forthcoming months.

This report presents a simple deterministic model, based on water balance technique, developed for Banjar sub basin of upper Narmada catchment. The rainfall is separated in to two components; One being the linear part which is causing direct runoff and other being the non linear component of rainfall absorbed to meet the requirement for soil moisture deficit. The hydrological drought is defined and then modelled using Cordery's approach which evaluates soil water deficit. The model can be used to estimate probability distribution of soil water deficits for each month of the year. From a given initial value it is then possible to estimate the distribution of soil water deficit in subsequent months. This means that from the current soil water deficit, probability of being above or below a chosen value during future months, can be determined.