Application of Gray and Fuzzy Methods for Rainfall Forecasting

Abstract

The forecasting of future rainfall is one way to extend the lead time of flood forecasting. This study proposes a rainfall forecast model based on a gray model, in which model parameters are estimated by using a fuzzy goal regression method. A one-time step forecasting technique is introduced to improve forecasting. This improvement allows for forecasting further ahead of the event in question. Ten historical storm events are considered to calibrate and verify the proposed model. Simulation results indicate that the proposed model exhibits reasonable rainfall mass curves and allows for rainfall hyetograph forecasting 1–3 h in advance.