ESTIMATION AMOUNT OF SUMMER REGIONAL HEAVY RAINFALL USING THE AVERAGES OF RADAR VPRs TOGETHER WITH RAIN GAUGE ADJUSTMENT

A method of estimating precipitation using the averages of radar VPRs together with gauge adjustment is presented. Focusing on the several events of heavy rainfall occurred in the mid-lower reaches of the Yangtze river in the summer of 2002 and 2003, the radar reflectivity factor data of volume-scan mode acquired by the CMA new generation S-Band radar deployed in Yichang and Hefei, and the corresponding 10-min average of gauge precipitation records in the range of the 100 km radius centered at above radar locations are used to calculate possible short-term average of VPRs at the ground-level, and are further to retrieve the precipitation amount and its relative errors. These objective data are also used to analyze characteristics of real-time VPRs in 10 min heavy rainfall. The precipitation amount, which is estimated by using the averagely adjustments of gauge records together with the fitted VPRs based on the least square method (LSM), is reasonable at surface level over a great part of a certain region. Compared with gauge records, the proposed method shows its capability to improve the precision of precipitation estimation in a regional scale, however, for the case of intensive convective precipitation, only the LSM is applicable. Characteristics of VPRs in a short time intensive heavy rainfall are helpful to estimate the amount of rainfall over a region without the gauge. Additionally, with combination of other data sources, characteristics of VPRS and be used to analyze the evolution of the precipitation process。