基于TRMM数据的广西西江流域降水时空分布特征

Spatio-temporal Distribution of Precipitation in Xijiang River Basin of Guangxi Based on TRMM Data

以广西西江流域为研究对象,以TRMM数据为主要数据源,利用研究区15个气象站降水实测数据,使用相关系数、相对偏差和均方根误差对1998—2013年TRMM降水数据进行验证,并在此基础上对广西西江流域的降水时空分布特征进行分析,结果表明:1)TRMM 3B43降水数据与气象站点实测降水数据具有较好的一致性,年尺度和月尺度相关系数分别是0.79和0.92(α<0.01),可以代表研究区实际降水情况;2)在降水时间分布上,1998—2013年间年降水量呈微弱的下降趋势,流域降水的季节分配不均匀,大部分降水集中在5至8月;3)在降水空间分布上,降水整体由东向西逐渐递减,春季(3—5月)的降水中心在流域东部,夏季(6—8月)移至西南部,秋季(9—11月)继续停留在西南部,冬季(12—2月)又移回东北部。

Xijiang River basin in Guangxi is chosen as the research object, using TRMM data as the main data source. First, the accuracy of TRMM 3B43 data was evaluated by comparing with observed data from 15 meteorological stations. Then, distribution patterns of precipitation were characterized based on the TRMM 3B43 data. The results indicated that： 1） The TRMM 3B43 data was usable to replace the rain gauge data. The correlation coefficient between TRMM 3B43 data and rain gauge data were 0.79 and 0.92 at annual and monthly scale respectively. 2） The temporal distribution pattern of precipitation presented slight escalating trend year-to-year from 1998 to 2013, and unevenly distributed within each year with most of the rainfall concentrated in wet season from May to August. 3 ） The spatial patterns of precipitation generally decreases from east to west annually, with the dry region located in the west part of the Xijiang river basin. In addition, spatial patterns of precipitation on seasonal scale vary greatly from northeast to southwest. In Spring, the rainfall center located in east part, while in summer, the rainfall center shifts to southwest part. In Autumn, it remains in the southwest part, while in winter, the center moves back to the northeast.