三峡库区(重庆段)TRMM降水实用性分析及时空特征

The Applicability Analysis of TRMM Precipitation in the Three Gorges Reservoir Area of Chongqing and Its Spatial-temporal Distribution

以三峡库区（重庆段）为研究区,利用17个气象站点的实测降水量分别在年、季、月尺度上验证TRMM（Tropical rainfall measurement mission）卫星降水数据的精度,并基于TRMM降水数据分析了研究区的降水时空分布特征。结果表明：①TRMM降水与站点实测数据存在显著的线性相关性,数据在该研究区具有较好的实用性。年尺度上,拟合优度R2=0.79,通过a=0.01置信度检验,相关系数R=0.89;季尺度上,各季节都通过a=0.01置信度检验,春季拟合优度相对较低（R2=0.62）;月尺度上,拟合优度R2=0.71,通过a=0.01置信度检验,相关系数为0.84。②降水空间分布整体上呈由西南向东北逐渐递增的趋势,高值区分布在东北部区域,低值区分布在西南部区域,中值区分布在中部、南部以及西部的山脊边缘区域。③降水差异显著,夏季最多,冬季最少;大部分降水集中在5~8月,占全年降水的60%左右,12月到第二年2月降水仅占全年的5%左右。

For the study of the three gorges reservoir area of Chongqing, the applicability of TRMM （ Tropical Rainfall Measurement Mission） 3B43 precipitation data has been verified by the measured data getting from 17 meteorological stations on the year, the sea- son and the month scale. On this basis, this paper analyzes the spatial and temporal distribution of precipitation in the study area based on the TRMM precipitation data. The result showed that： （1） Manipulative direction, there exist obvious linear correlation between TRMM precipitation and site data , so this can prove TRMM precipitation has good practicality. On the year scale, corre- lation coefficient R = 0. 89. On the season scale, TRMM precipitation data has through a 0. 01 confidence level. The eorrela tion coefficient is relatively low （R = 0. 79） in the spring. On the month scale, the correlation coefficient is 0. 84. （2） On the spatial distribution of precipitation, the precipitation shows a gradually increasing trend from southwest to northeast on the whole. High values appeared in the northeast region. Low values appeared in the southwest region and the area of median wllues appeared in the central region, the southern region and the western edges of the ridge area. （3） On the temporal distribution of precipitation, there are significant differences in the seasonal precipitation. The maximum rainfall appeared in summer and the minimum rainfall appeared in winter. The aspect of the month, precipitation mostly concentrated in May--August, accounting for about 60% of an- nual precipitation. However, the precipitation accounting for about 5% of annual precipitation from the December to） the February in the second year .