THE PROJECTION OF FUTURE RAINFALL CHANGE OVER KEDAH, MALAYSIA WITH THE STATISTICAL DOWNSCALING MODEL

Abstract

Climate change is a crucial global issue. The trend of climate change is very important to the agriculture because its uncertainty may cause the reduction in crop yield and economic losses. Therefore, the climate model has been widely used to simulate the future climate variation based on atmospheric circulation pattern (predictors). This study utilized the Statistical Downscaling Model (SDSM). The purpose of this paper is to describe the climate variation in Malaysia’s prominent agricultural state, Kedah, in the context of climate change scenario based on the temperature, rainfall intensity, wet and dry spell length. Twenty rainfall stations were selected in Kedah as they had lesser percentage of missing data to control the quality and capability of result. Based on the SDSM simulation result, the climate trend is not much different from the historical data but it is expected to increase continuously for every interval period from the year 2010 to 2099. The increasing of temperature is predictable up to 32oC during south-west monsoon season and 40oC during north-east monsoon season. The rainfall pattern shows that the intensity is estimated to focus on the middle area of Kedah such as Kota Setar, Pendang, Yan, Kuala Muda, Sik, and Baling district and is expected to increase during north-east monsoon season even when the wet spell during that period is relatively short. The longest dry spell which is expected to assault Kedah Peak and Kodiang in the future may cause water scarcity at critical areas.