Quality check of rain gauge data for quantitative precipitation estimate

Tóm tắt

The Quantitative Precipitation Estimation (QPE) method of the Japan Meteorological Agency (JMA) using radar and rain gauge data has been started to be deployed at the Vietnam Meteorological and Hydrological Administration (VNMHA) since 2019 through a technical cooperation project of the Japan International Cooperation Agency (JICA). Quality control of radar and rain gauge data is a vital issue in keeping the accuracy of QPE. Especially rain gauge data is essential because QPE processes regard rain gauge data as exact values in calibration processes. VNMHA had yet to develop a quality control system and regular maintenance scheme for Automatic Weather Stations (AWS) and Automatic Rain Gauges (ARG). In order to make a reliable QPE product, a quality check for rain gages data comparing mutual rain gauge data experimented and 1) missing data ratio, 2) proportion to mean of nearly ten stations, and 3) double sum curve check was selected as thresholds to select relatively reliable rain gauge stations. As a result of the quality check for rain gauge data in May 2023, 1,299 stations were chosen, and QPE with rain gauges selected showed stable precipitation distribution.