TRMM卫星降水数据在老哈河流域的精度评估

采用地面雨量站点观测降水作为基准数据,评估热带降雨观测计划(TRMM)最新一代降水产品3B42V7在高纬度半干旱的老哈河流域的精度。结果显示:TRMM 3B42V7在老哈河流域较基准降水系统偏大,平均偏差为17.46%,相关系数为0.73,平均意义上日卫星降水精度相对较高;但TRMM 3B42V7绝对值偏差达到81.26%,在绝对值意义上日卫星降水精度较低;经过GPCC地面月降水量偏差校准,TRMM 3B42V7精度在月尺度上有较大提高,绝对偏差为21.95%,相关系数达到0.98;TRMM 3B42V7精度同纬度和高程存在明显的相关关系;TRMM3B42V7能较好反映老哈河流域日降水事件并展现降水的空间分布特征。因此,TRMM 3B42V7可用于老哈河流域月尺度的水文过程模拟、水资源评价与规划等相关研究。

Evaluation of accuracy of Laoha river basin by data of TRMM satellite precipitation

Taking the ground site observation rainfall precipitation as benchmark data,the paper assessed the precision of the latest generation precipitation product 3B42V7 of tropical rainfall observation plan(TRMM) in Laoha river basin in northern semi-arid area. The result shows that the TRMM 3B42V7 in a benchmark Laoha river basin precipitation system is larger, the average deviation is 17.46%, the correlation coefficient is 0.73, the, the precision of satellite daily precipitation is relative high in average sense; But TRMM 3B42V7 absolute deviation reaches 81.26%, the precision of satellite precipitation in an absolute sense is low; After the deviation calibration of month GPCC ground rainfall,the precision of TRMM 3B42V7 on month scale has greatly increased,the absolute deviation is 21.95%, the correlation coefficient is 0.98; The accuracy of TRMM 3B42V7 has obvious correlation with latitude and elevation; TRMM 3B42V7 can better reflect the spatial distribution characteristics of precipitation and precipitation events in Laoha river basin. Therefore,TRMM 3B42V7 can be used for the simulation of monthly scale hydrological process, the evaluation and planning research of water resources in Laoha river basin watershed.