Rainfall Data Assessment from X-Band Polarimetric Radar for Small Drainage Area

• Published in: Science and Technology Asia
• Main Author: Hasan N.A.; Goto M.; Miyamoto K.; Iguchi M.; Tamunaidu P.; Ros F.C.
• Format: Article
• Language: English
• Published: Thammasat University 2024
• Online Access: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85206574493&partnerID=40&md5=a1ca117d576f8a80dde433cb88089704

For disaster monitoring and mitigation, an X-Band polarimetric radar can provide one or two minutes of rainfall data in small areas. However, this weather radar is not available in tropical nations such as Malaysia, which has suffered from flash floods and flooding, particularly during the monsoon season. As a result, this study evaluates rainfall estimation strategies for small drainage regions as part of a proposal for a new framework of rainfall estimation in Malaysia that employs X-Band polarimetric radar. It begins with raw data conversion, then clips the DEM, selects the drainage area in Kagoshima, and finally plots the hyetograph for rainfall events. The extraction of X-Band polarimetric rainfall data from AMeDAS ground data was investigated. The statistical validation results reveal a relatively positive association between X-Band polarimetry and AMeDAS, with an R2 value of around 24% for model fit. Furthermore, using QGIS to compare rainfall distribution results for both data sets reveals that AMeDAS data does not accurately reflect actual rainfall monitored by X-Band polarimetric radar because there are no AMeDAS stations in the drainage area, and the X-Band polarimetric radar distribution image is also real-time. All drainages were classified as heavy rain in the upper stream, indicating the precise location of the highest intensity and the possibility that the area closest to the drainage would experience a disaster such as a flood. This paper concludes with suggestions for future works. © 2024, Thammasat University. All rights reserved.