基于雷达和雨量站的权重校准法研究及其应用

Research and application of weight calibration method based on radars and rainfall stations

利用雷达测量降雨可获得流域面上的瞬时降雨分布,但数据有一定的误差,可利用雨量站实测资料修正。以湖北省白莲河水库流域为例,首先运用集对分析方法确定雷达估算降雨场的Z^I关系,然后结合流域雨量站点对雷达估算降雨量进行校准。在此基础上提出了一种基于雷达和雨量站点资料的权重校准法,通过雨量站确定流域内各网格的降雨量级,对各网格的雷达测量降雨量精度进行调整,以充分发挥两种降雨估算方法各自的优势,得到比较理想的流域面雨量,最后将其输入到三水源新安江洪水预报模型,与其他降雨估算方法进行比较,洪水预报精度有一定提高。

Taking the basin of Bailianhe Reservoir in Hubei Province as an example, we apply the set pair analysis to deter- mine the Z - I relationship of radar - estimated precipitation field, and then calibrate the radar - estimated precipitation by the data of rainfall stations in the basin. We put forward a method of weight calibration for radar - estimated precipitation based on the observed data of radars and rainfall stations, which can exploit both advantages of radars and rainfall stations, namely, deter- mining the precipitation levels in the basin grids by rainfall stations and adjusting the precipitation accuracy of each grid by radar - estimated precipitation, and get an ideal surface rainfall amount of the basin. At last, the calibrated precipitation is input into the Three - source Xin^mjiang Flood Forecast Model. The result indicates that application of this calibration method can improve flood forecasting accuracy to a certain degree.