TRMM卫星3B43降水数据在黄河流域的精度分析

利用黄河流域90个气象站点实测降水数据，分别从流域和格网两个空间尺度，运用相关分析、相对误差等统计分析方法对TRMM卫星3B43 v7降水数据在黄河流域的精度进行了评估，在此基础上分析了精度评价指标的空间分布特征，讨论高程、降水强度等因素对精度的影响。结果表明：①在流域尺度上，TRMM月降水数据与站点实测月降水数据呈高度线性相关，TRMM降水数据比站点实测降水数据略微偏高。②在格网尺度上，大部分格网的TRMM月降水数据与站点实测月降水数据的相关系数较高，偏差较小。③TRMM降水精度与降水强度、高程相关，TRMM降水量与实测降水量的平均绝对误差呈自东南向西北递减规律，与黄河流域降水分布规律相一致；相对误差、平均误差和平均绝对误差等指标随着高程的增加呈现逐渐减小的趋势。整体上，对于黄河流域，随着降水量的增多，TRMM数据倾向于低估降水量；高海拔区域，TRMM低估降水量，低海拔区域，TRMM高估降水量。通过评估TRMM卫星降水产品在黄河流域的精度，为本地区地面降水产品提供有效补充。

Accuracy Analysis of TRMM 3B43 Precipitation Data in theYellow River Basin

Based on the correlation analysis and relative error methods, the accuracy of TRMM 3B43 v7 precipitation data at the watershed and grid scale in the Yellow River Basin was validated using 90 meteorological stations data. The spatial distribution characteristics of the accuracy evaluation indexes were analyzed. The influence of elevation and precipitation intensity on the accuracy of TRMM precipitation was discussed. The results show that: (1) At the basin scale, the TRMM monthly precipitation data is highly linearly related to the measured precipitation data at the site. TRMM precipitation data is slightly higher than the site-measured precipitation data. (2) At the grid scale, the TRMM monthly precipitation data of most grids have a high correlation coefficient with the measured precipitation data at the site. The deviation between TRMM precipitation and in site measured precipitation is small. (3) The accuracy of TRMM precipitation is related to precipitation intensity and elevation. The average absolute error between TRMM precipitation and measured precipitation is decreasing from southeast to northwest, which is consistent with precipitation distribution in the Yellow River Basin. The relative error, average error and average absolute error tend to decrease with the increase of elevation. Overall, over the Yellow River Basin, TRMM data tend to underestimate precipitation as precipitation increases. TRMM data underestimates precipitation in high altitude areas, overestimates precipitation in low altitude areas. By assessing the accuracy of TRMM satellite precipitation products in the Yellow River Basin, it provides an effective supplement for ground precipitation products in the region.