MULTIPLE INPUT, SINGLE OUTPUT RAINFALL RUNOFF MODEL

Abstract

The problem of predicting the runoff form a storm in a catchment has received considerable attention of the hydrologists in the past. A large number of methods are proposed but the response function based method such as the unit hydrogrph method is most popular and widely used. One of the assumption followed in these methods is that the rainfall is occurring simultaneously on the whole catchment with same intensity, which is practically not possible. Non uniformity in rainfall values over the catchment increases with its size. For large catchment it may even happen that some part of the catchment would not have any rain at all during the storm period. Therefore to derive a response function for a large catchment, we can divide it into a number of sub-catchments having the uniform rainfall in that sub-catchment. In the present thesis first a multiple input, single output non-linear rainfall runoff model is formulated on the basis of review of literature. Rainfall and runoff data on Narmada catchment upto Jamtara have been used for calibration and verification of the model. Results have been obtained for one, two and three rainfall inputs from the Narmada catchment with its discharge at Jamtara being the output. Both linear and non-linear approaches were tested. Better results have been obtained both during calibration and the verification period when number of inputs in the model are increased.