Analysis of Rainfall Trend and Temporal Patterns: A Case Study for Penchala River Basin, Kuala Lumpur

Abstract

Changing of rainfall pattern and trend has increased the flooding risk in urban areas in the recent decades. This study aimed to examine the rainfall trends and its temporal rainfall pattern in Penchala River basin. Rainfall data of 5-min interval from 2005 to 2014 were obtained from Department of Irrigation and Drainage Malaysia (DID). The Mann-Kendall (MK) test was used to detect the trends of rainfall while average variability method (AVM) was used to derive the rainfall temporal pattern in the studied river basin. The historical rainfall data in Penchala River basin show a downward trend in the past 10 years, especially in February. Meanwhile, positive trends were detected in October, November, and December. Most of the rainfall events in Penchala River basin are categorized as advanced and intermediate type pattern. Higher fraction of rainfall occurs at the early part of storm event in the Penchala River basin, compared to that of Kuala Lumpur region.