降雨空间插值方法及在清江流域的应用

Rainfall Spatial Interporation Methods and Their Applications to Qingjiang River Basin

将普通克里格法、协同克里格法和反距离加权法3种空间插值方法应用于清江流域的降雨空间插值,比较了它们的应用效果,并分析了它们插值效果不同的原因.其中协同克里格法在应用时考虑了海拔高度对降雨量插值结果的影响.结果表明,两种克里格方法的插值结果的误差要远远小于反距离加权法,并且插值所得到的等雨量线更光滑.对于两种克里格方法,协同克里格法要优于普通克里格法,前者比后者的MAE值要小10%.反距离加权法明显不如两种克里格法的原因是该方法不能准确反映相邻站点的空间依赖关系.而协同克里格法优于普通克里格法是因为协同克里格插值法考虑到了地形对降雨量的影响,因而更适用于清江流域这样的山地流域.

The three spafial interpolation methods are applied to the rainfall spatial interporation for the Qingjiang River basin： ordinary Kriging,co-Kriging and inverse distance weighting（IDW）.Their application results are compared and analyzed.For the co-Kriging method,the altitudes of the raingauges are considered to improve the interpolation results.The results show that,the interpolation errors of the 2 Kriging methods are much smaller than that of the IDW method.Also,the isohyet lines produced by the 2 Kriging methods are much smoother than that by the IDW method.For the 2 Kriging methods,the co-Kriging is superior than the ordinary Kriging,in the sense that,the mean absolute error of the co-Kriging is less than the ordinary Kriging by a rate of 10%.The reason for the IDW method being inferior than the 2 Kriging methods is that,the IDW method cannot take into account the spatial dependencies of adjacent raingauges in the basin.The reason of co-Kriging being superior than the ordinary Kriging is that the former taking into account of the topographic effects on rainfalls,therefore more suitable for mountainous river basins like Qingjiang River.