Calibration of rainfall-reflectivity in northern region of Peninsular Malaysia

Abstract

This project studies are about to derive new ZR relationship at the Alor Star radar. ZR relationship is applied to estimate the rainfall. A long time ago, Marshall and Palmer were created an equation to estimate the rainfall at 1947. The equation is written in form Z=200R1.6 . Even though, this still new in Malaysia. Estimating accurately rainfall is very important. This is because it can avoid the flood, landslide and natural disaster. Base on previous research, Marshall Palmer equation is not relevant to use in Malaysia. So that, new ZR relationship for Alor Star radar should be deriving. ZR relationship should be justified to make sure that Marshall Palmer equation is not relevant for estimate the rainfall in Malaysia. The result shows, the difference between the mean radar rate and mean rain gauge rate has large error. That proved Marshall Palmer equation is not relevant to use in Malaysia, especially at the Alor Star radar. The sensitivity analysis by applying in the statistical measures can determine the value of the parameter of ZR relationship. Then, doing calibration processes done to find the best value of the parameter of ZR relationship. After the calibration process, the new proposed value parameter is 27. Then the new ZR relationship written in form Z = 27R1.6 . After the validation process, it proves that the new ZR relationship is relevant to estimation the rainfall in Malaysia especially at the Alor Star radar. That can be concluded that the new ZR relationship for Alor Star radar is Z = 27R1.6 . Marshall Palmer not relevant because of geographical factors. By using new ZR relationship, the radar can improve the estimation about rainfall. Therefore, it can minimise the natural disaster, landslide and flood. Besides that, it can assist humanity to plan their daily routine.