不同站网对极端降水事件变化监测的影响

利用1961—2011年51年的日降水资料,以2400多站组成的国家级站网为基准,通过分析不同站网对中雨日数、大雨日数、强降水量和极强降水量4种极端降水指数监测差异,对中国不同地面观测站网对中国极端降水事件的代表性进行了评估。研究发现,各站网对极端降水事件变化的时间和空间分布监测精度由高到低依次为:基本基准站网,基本站网,基准站网,GCOS站网。GCOS站网和基准站网对各降水指数的空间分布的影响与标准站网相差较大。基本基准站网和基本站网对各极端降水指数变化方向及变化速率的空间分布与标准站网非常一致,但在西南地区北部、东北中东部地区、长江中游北侧局部地区的观测精度仍然不理想。

Effect of Station Density Changes on Variability Monitoring of Extreme Precipitation Events in Mainland China

Based on the daily precipitation data from 196 to 2011 in China, a comparative analysis is made of the changes of the numbers of moderate rain days and heavy rain days, strong precipitation, and extreme precipitation under different station networks to assess the representativeness of different station networks for extreme precipitation events. The results show that the monitoring precision in time and spatial distribution of the station networks for extreme precipitation events changes are in the following order: the basic & reference station network, basic networks, reference station network, and GCOS station network. The influences of spatial distributions of the GCOS station network and the reference station network on the precipitation index differ from the standard station network greatly. The space distributions of various indexes under the basic & reference and basic station networks are the closest to that of the standard station network, but the monitoring precisions in the northern Southwest China, the eastern and central Northeast China, and some areas of the northern Yangtze River are still unsatisfactory.