Development of Regional Climate Model (RCM) for Cameron Highlands based on Representative Concentration Pathways (RCP) 4.5 and 8.5

Development of local climate is important for climate hazard assessment. Cameron Highlands was chosen as study area (longitude from 101°21’ to 101°30’ and latitude from 4°19’ to 4°37’) for climate downscaling. This paper presents the work of downscaling techniques and regional climate model (RCM) development. The second-generation Canadian Earth System Model (CanESM2) based on the representative concentration pathways (RCP) 4.5 and 8.5 was applied to develop the local climate model for the period 2020-2100. The climatic parameters chosen were temperature (maximum and minimum) and rainfall. The simulated RCMs are then analysed using statistical reliability including Pearson correlation coefficient, linear regression, root mean square error (RMSE) and probability density function (PDF). The result showed that the simulated maximum, minimum temperature, and rainfall are most likely to follow RCP 8.5 scenario. Precipitation threshold for occurrence of flood event was estimated using intensity duration frequency (IDF) relationship generated by maximum precipitation. Return period of two years and four hours rainfall duration is used for threshold estimation as the rainfall is convective. The daily rainfall threshold for flood occurrence is estimated to be 11.3 mm/hr