A time series model to predict the runoff ratio of catchments of the Kalu ganga basin

Abstract

Forecasting runoff ratio variation is important since it can be used to calculate the runoff of a river catchment for a given rainfall on a particular day. The model SARIMA (Seasonal Auto-Regressive Integrated Moving Average) developed for this purpose which was based on Auto Correlation Function (ACF) and Partial Auto Correction Function (PACF), was fitted to the runoff ratio data of the Ratnpura catchment of the Kalu ganga basin. The appropriateness of the same model was tested against two other catchments; Dela and Ellagawa of the same river basin and found to be suitable.