TRMM面降雨量数据在鄱阳湖流域的精度评价

Precision evaluation for TRMM precipitation data in Poyang Lake Basin

利用2011年和2012年鄱阳湖流域及附近的47个台站观测数据对TRMM V7降雨量数据进行了日、月、年尺度的精度检验,并分析了该流域降雨与地面植被覆盖和地形的关系.结果表明,TRMM数据的精度随尺度而变化,TRMM日降雨量与地面实测值相关性一般,相关系数（R）为0.67左右,而均方根误差（RMSE）在10~20 mm之间;月和年尺度降雨量精度较好,R2分别为0.897和0.845,平均相对误差小于85%;日、月和年尺度的降雨量与地面植被覆盖度无明显相关性,但地形对降雨量有一定的影响,地形较高的山区降雨比平原区要多.月和年尺度的TRMM降雨量数据可应用于大、中尺度的水文和生态模型.

In this paper,a comprehensive evaluation was conducted for TRMM V7 precipitation data,including daily,monthly and annual precipitation. The in-situ measured precipitation data was collected from47 ground weather stations in Poyang Lake Basin in 2011 and 2012. The results show that the estimated daily precipitation using TRMM data is significantly different from the in-situ measured precipitation,only achieving a correlation coefficient（ R） of 0. 67 and the root mean squared error（ RMSE） ranging from 10 mm to 20 mm; and that the estimated monthly and annual precipitations from TRMM data are consistent with the in-situ measured precipitations,with R2 of 0. 897 and 0. 845,and mean relative error（ MRE） is less than 85%. The effect of vegetation cover rate on precipitation is not obvious in the Poyang Lake Basin in our study,but the precipitation is relative to terrain,the precipitation is larger in mountain areas with higher elevation than in plain areas. The monthly and annual precipitation data can be potentially applied in hydrological and ecosystem models.