A simple and efficient conceptual catchment model allowing for spatial variation in rainfall

In developing countries, the use of mathematical models in hydrological forecasting is increasing, making for optimal planning and management of water resources systems. Such application, however, faces different problems. One of these problems is that computers may not be available. Even if they are available, computer time is expensive. Hence, there is a need for simple models which can be run on pocket calculators or which are computer-time efficient, with high accuracy. This paper presents a rainfall-runoff model with a very simple structure. With simple algorithms, the model can be used with computers with small memory capacity. A method for estimating mean areal rainfall, representing the detailed distribution of rain over an area, is also put forward. The model has been applied to a small, mainly rural catchment in northern Tunisia for both single rainfall event simulation and continuous simulation for longer periods. The outcome was most encouraging. In the present paper the measured and ...