Statistical analysis on rainfall and discharge data : in study area in Johor river basin

Abstract

Johor river is one of the several river that drain into Tebrau Strait ( Selat Tebrau). The Johor river catchment is centered about 35E, 0.5N. Rainfall and flow data for the period 1980 – 2011 were used in this study. The time series of monthly values of rainfall and discharge were analyzed using statistical methods. Trend analysis was performed using Mann-Kendall trend test. This was done in an attempt to determine whether or not there have been any significant change in rainfall and discharge over this catchment. Forecasting analysis which is ARIMA model and Smoothing Technique were used to select best model to predict for 5 years ahead. Best fitted model were analyze using statistical criteria of Mean Square Error (MSE) and Mean Absolute Percentage Error (MAPE) The best model used for forecasting the rainfall and discharge data is ARIMA model. While rainfall and discharge data analysis for the station slightly show the same trend before and after forecast.