@Article{G.2011,
author="G., Zhao
and R., Chu
and T., Zhang
and J., Li
and J., Shen
and Z., Wu",
title="Improving the rainfall rate estimation in the midstream of the Heihe River Basin using raindrop size distribution",
journal="Hydrology and Earth System Sciences",
year="2011",
volume="15",
number="135",
abstract="During the intensive observation period of the Watershed Allied TelemetryExperimental Research (WATER), a total of 1074 raindrop size distributionwere measured by the Parsivel disdrometer, the latest state-of-the-art opticallaser instrument. Because of the limited observation data in Qinghai-TibetPlateau, the modelling behaviour was not well done. We used raindrop sizedistributions to improve the rain rate estimator of meteorological radar inorder to obtain many accurate rain rate data in this area. We got therelationship between the terminal velocity of the raindrop and the diameter (mm) of a raindrop: v(D) = 4.67 D <sup>0.53</sup>. Then four types of estimators forX-band polarimetric radar are examined. The simulation results show that theclassical estimator R ( Z <sub>H</sub>) is most sensitive to variations in DSD and theestimator R ( K <sub>DP</sub>, Z <sub>H</sub>, Z <sub>DR</sub>) is the best estimator for estimatingthe rain rate. An X-band polarimetric radar (714XDP) is used for verifyingthese estimators. The lowest sensitivity of the rain rate estimator R ( K <sub>DP</sub>, Z <sub>H</sub>, Z <sub>DR</sub>) to variations in DSD can be explained by the following facts. The difference in the forward-scattering amplitudes athorizontal and vertical polarizations, which contributes K <sub>DP</sub>, isproportional to the 3rd power of the drop diameter. On the other hand,the exponent of the backscatter cross-section, which contributes to Z <sub>H</sub>, is proportional to the 6th power of the drop diameter. Becausethe rain rate R is proportional to the 3.57th power of the dropdiameter, K <sub>DP</sub> is less sensitive to DSD variations than Z <sub>H</sub>.",
issn="1607-7938"
}