长江流域夏季日面雨量的精度与代表性站数关系研究

Analysis on the Accuracy and Representative Stations of Summer Daily Rainfall in the Yangtze River Basin

为探讨不同测量站配置数对统计长江流域夏季日面雨量精度的影响,选取金沙江下游、鄂东北、青弋水阳江3个流域作为研究对象,并挑选出不同站网分布,统计各站网分布计算的2016—2018年夏季日面雨量,运用平均绝对误差(MAE)、均方差(MSE)和相关系数(r)三个技术指标来评价各流域夏季日面雨量精度与站数之间的关系。结果表明:各流域夏季日面雨量精度均受站数变化的影响,MAE、MSE均随站数的增加而减小,但当站数增加到一定数量之后趋于稳定,r也有相同的变化规律,只是随站数增加而增大。同时,通过计算三个技术指标随站数平均变化值,定量揭示了以上变化规律并得到金下、鄂东北、青弋水阳江流域代表性站数分别为405站、293站、126站,与现有站数相比,分别减少25.1%、55.8%、56.6%,可为计算长江流域夏季日面雨量选用站数和站网布局提供参考。

In order to explore the influence of different number of station configurations on the accuracy of statistics of daily rainfall in the Yangtze River Basin in summer,the lower reaches of Jinsha River,northeast Hubei and Qingyi Shuiyang River Basin were selected as the research objects,and different number of stations was selected by station pumping method.Then the summer daily area rainfall of each basin from 2016 to 2018 were calculated by Tyson polygon method,and three technical indexes:mean absolute error(MAE),mean square error(MSE)and correlation coefficient(r)were used to evaluate the relationship between the accuracy of daily rainfall and station number in summer.The results show that:the accuracy of daily surface rainfall is affected by the number of stations.MAE and MSE decrease with the increase of the number of stations,but when the number of stations increases to a certain number,they tend to be stable,and r also has the same change law,but increases with the number of stations.At the same time,by calculating the average change value of the three technical indicators with the number of stations,the above variation laws are quantitatively revealed,and the representative stations in Jinxia,northeast Hubei and Qingyi Shuiyang river basins is 405,293 and 126 respectively.Compared with the number of existing stations,it decreases by 25.1%,55.8%and 56.6%respectively.It can provide reference for selecting the number of stations and the layout of stations in the Yangtze River Basin.