NEURAL-NETWORK MODELS OF RAINFALL-RUNOFF PROCESS

Spatially distributed rainfall patterns can now be detected using a variety of remote-sensing techniques ranging from weather radar to various satellite-based sensors. Conversion of the remote-sensed signal into rainfall rates, and hence into runoff for a given river basin, is a complex and difficult process using traditional approaches. Neural-network models hold the possibility of circumventing these difficulties by training the network to map rainfall patterns into various measures of runoff that may be of interest. To investigate the potential of this approach, a very simple 5 X 5 grid cell synthetic watershed is used to generate runoff from stochastically generated rainfall patterns. A backpropagation neural network is trained to predict the peak discharge and the time of peak resulting from a single rainfall pattern. Additionally, the neural network is trained to map a time series of three rainfall patterns into a continuum of discharges over future time by using a discrete Fourier series fit to the runoff hydrograph.