Spatial patterns of precipitation, altitude and monsoon directions in Hulu Kelang area, Malaysia

Abstract

Malaysia is characterized by a humid tropical climate with heavy rainfall. The annual temperature varies from 26 to 28°C while Malaysia is being one of the wet climate countries with as annual rainfall is approximately 2250 mm/year. Malaysia monsoon is arranged into two rainfall terms: the primary one coincident with the northeast monthly precipitation (December-March) and the other one with the southwest monthly rainfall in conjunction with inter-monsoon periods (April-November). The rainfall events are gauged at points of precipitation measurement networks in Malaysia. But, there is not full mapping of precipitation in relation with elevation all locations especially in mountains. This paper provides the relationship between monthly precipitation and elevation in the Hulu Kelang area based on Geographically Weighted Regression (GWR) method. Three periods of precipitation" the average monthly rainfall and two monsoons" has been studied in this area. The results of regression analyses performed between three conditions of monthly precipitation in the year and altitude. The mean absolute error (MAE) and the root-mean-square error (RMSE) verification results indicated that the whole year rainfall regression model works quite better than other results for interpreting the spatial variability of precipitation. The relation between original normal precipitation (1990-2010) and topography variables showed that study area precipitation is strongly controlled by elevation in the west region. The final map was represented that precipitation in the west region is generally higher than in east region of Hulu Kelang all around the year.