ANALISIS TREND HUJAN DI BANDARAYA IPOH PERAK 1970-2007 (Analysis of Rainfall Trend in Ipoh City, Perak 1970-2007)

Long term research on rainfall trends are important and viable in hydrological studies especially as a tool to identify and detect the changes occur in hydrological systems. The monthly and annual rainfall data from 1970 to 2007 were obtained from the Malaysian Meteorological Department and analyzed using statistical tests and Mann-Kendall test to detect changes (increased, decreased or stable), or the prevailing trend. The findings showed an increased trend in annual rainfall from 1970-2007 with an annual average of 2497 mm. The record also shows the increased trend of rainfall during the Northeast Monsoon and Southwest Monsoon over the same period. Maximum rainfall is in April and October during the inter-monsoon season. The record also shows that the Ipoh area receives the most rainfall during the Northeast Monsoon although the rain station is located on the west coast of Peninsular Malaysia with an average of 1016 mm. Monthly rainfall from 1970-2007 show a diverse variation. Based on the Mann-Kendall test (S), a declined trend was shown in May (-21), September (-25), October (-35) and December (-16) while the other months showed an increased trend. This situation clearly shows the complex variation of rainfall in the tropics. The current global climate change factor and local hydrometeorology trend are expected to affect rainfall and changes in land use especially the municipal activities that can be found in the middle of the Kinta River basin in particular the Ipoh City. [PUBLICATION ABSTRACT]