The rainfall runoff model is one of the most frequently used events in hydrology. It determines the runoff signal which leaves the watershed from the rainfall signal received by the basin. The present study develops an distributed approach to simulate the rainfall runoff process of a catchment. The catchment area has been divided in to the numbers of divisions equal to the numbers of rain gauge station. An lump model is also developed using average rainfall of the catchment. In case of lump model, average rainfall is calculated using thessian polygon method. In order to estimate runoff from...