基于MSWEP数据的太湖流域降水特性分析

基于高密度的地表雨量站网资料生成基准降水量,采用分类指标、体积分类指标和定量指标,在0.1°×0.1°的栅格尺度上解析了1979-2016年汛期MSWEP(multi-source weighted-ensemble precipitation)日降水数据的误差特征,并剖析了MSWEP对于太湖流域多种特征降水要素的辨识能力。结果表明:MSWEP对日降水量存在一定程度低估,且在山丘区和太湖湖区的降水精度相对偏低,但与地表降水之间总体上具有较强一致性;MSWEP对太湖流域不同时段的极值降水量和台风降水量、梅雨量和汛期降水量也具有相当表征能力;MSWEP既反映了太湖流域西部特别是浙西山丘区地形对降水的强化作用,还反映了太湖湖区大型水域对降水的抑制作用;MSWEP也探测到受城市化影响太湖流域年最大1 d降水量在平原区东部存在高值地带。

Analysis of precipitation characteristics in Taihu Lake Basin based on MSWEP

Based on the benchmark precipitation generated by high-density surface precipitation network data, the error characteristics of daily precipitation data of MSWEP(multi-source weighted-ensemble precipitation)in flood season from 1979 to 2016 were analyzed on the grid scale of 0. 1°×0. 1°, using the classification index, volume classification index and quantitative index. And the identification ability of MSWEP for various characteristic precipitation elements in Taihu Lake Basin were analyzed. The long series comparison between MSWEP and ground benchmark precipitation shows that MSWEP underestimates the daily precipitation to a certain extent, and the precipitation accuracy in hilly area and Taihu Lake area is relatively low. But there is a strong consistency between MSWEP and ground precipitation overall. MSWEP shows a describing ability for extreme precipitation in different periods, typhoon precipitation, plum precipitation and flood season precipitation of the Taihu Lake Basin. MSWEP can reflect not only the intensification of precipitation in the west of Taihu Lake Basin, especially in the hilly area of Western Zhejiang Province, but also the inhibition of precipitation in large water areas of Taihu Lake. Meanwhile, MSWEP also detected a high value area in the east of the plain where the annual maximum daily precipitation of Taihu Lake Basin is affected by urbanization.