多源降水数据在长江上游流域比较研究

降水是洪水预报重要的输入因子,是保证洪水预报精度的前提条件。提出一种从站点、子流域以及全流域3种空间尺度上评价水情遥测降水数据精度的方法。采用该方法,以国家气象信息中心公开发布的日降水数据为基准,针对覆盖宜昌-宜宾425 000 km2的377个遥测雨量站降雨数据进行精度评价。在日、月时间尺度上,综合评价了中国长江三峡集团所属的遥测雨量数据精度特征。结果表明,其遥测雨量数据与国家气象信息中心公开发布的日降水数据,具有较高的相关度,相关指标R2到达0.81。部分数据受到地形以及站点位置差异等因素的影响,存在一定差异。这些差异为雨量站的调整和补充提供重要依据。为验证其他遥测站网的降水数据精度提供了范例,利用该方法,可对运行多年的遥测雨量站网进行评价,也可开展多源降水融合相关工作,提高地面遥测降水数据的代表性和准确性。

COMPARATIVE STUDY ON VARIOUS RAINFALL DATA IN UPPER REACHES IN YANGTZE RIVER

Rainfall is an important input factor of flood forecasting and a prerequisite for ensuring forecasting accuracy. This paper proposes a method to comprehensively evaluate and compare the accuracy of telemetry stations estimates at three spatial scales:point scale, sub-catchment scale and the whole-basin scale. Using this method, benchmarked against daily precipitation data that National Meteorological Information Center published, we evaluated the accuracy of the telemetry rainfall system with 377 gauges covering Yibin to Yichang, whose area is 425 000 km². In daily and monthly time scale, we revealed the influencing factors and the characteristics of telemetry rainfall dataset of China Three Gorges Corporation. The results showed that the correlation of rainfall between the data was relatively high. The daily efficient coefficient of R² reached 0.81. There are a few differences in the data which affected by such factors as the position and the terrain. These differences provide an important basis for the adjustment and supplement of the precipitation station. This article provides a paradigm to verify the accuracy of some rainfall data by telemetering stations. The method could evaluate the situation of the data by telemetering stations, and serve as a basis for the future study of multi-source data fusion of rainfall, improving the ground telemetry rainfall data of representative and accuracy.