新疆地区降水分布的空间插值方法比较

Comparison of spatial interpolation methods for precipitation distribution in Xinjiang region

利用新疆及周边地区的154个气象站点资料,采用反距离权重法(IDW)、普通克里金法(Kriging)、协同克里格法(Cokriging)、贝叶斯法(EBK)和ANUSPLIN软件5种方法,对新疆地区1995-2004年10年间的月降水量空间插值模拟结果进行了交叉检验。结果表明,在新疆地区,5种方法的插值精度表现为ANUSPLIN>Cokriging>EBK>Kriging>IDW,并随月份有所变化,平均绝对误差(MAE)和均方根误差(RMSE)表现为秋冬两季误差低于春夏两季,平均相对误差(MRE)的值在春季和秋季较高。与已建立的新疆的降水量分布格局进行比较发现,ANUSPLIN兼顾了插值曲面的准确度与平滑度,它较为准确地反映了新疆地区降水空间分布的特征,EBK法在4月和7月插值结果与实际偏差较大,而1月和10月插值效果较好,Cokriging法插值结果均质性较差,并不能反映新疆实际降水的空间分布。Kriging法在10月插值效果较好外,在其他3个月的插值效果不好,IDW法的最大值或者最小值主要分布在台站周围,与实际情况相差较远。

Based on the data from 154 meteorological stations in Xinjiang district and surrounding areas,five interpolation methods [inverse distance weighting( IDW),ordinary Kriging( Kriging),Collaborative Kriging( Cokriging),Empirical Bayesian( EBK) and ANUSPLIN spatial interpolation]were implemented for simulation and cross examination of monthly average precipitation from 1995 to 2004. The test results showed that the interpolation accuracy,from most to least accurate,was ANUSPLIN,Cokriging,EBK,Kriging and IDW. Accuracy varied between months. The Root Mean Square Error( RMSE) and the Mean Absolute Error( MAE) showed lower value in winter and spring than in summer and autumn; the Mean Relative Error( MRE) was higher in spring and autumn. While comparing precipitation distribution in Xinjiang,ANUSPLIN considered both the accuracy and smoothness of the interpolation surface,which more precisely reflected the spatial distribution of precipitation. Interpolation results from the EBK method were much higher than the actual precipitation distribution in April and July,while the interpolation was better in January and October. Cokriging interpolation results were uneven and did not accurately reflect spatial distribution. Interpolation using the Kriging method was better in October,but less so for the other three months( January,April and July). The maximum or minimum value of the IDW method was mainly distributed around the station and differed with the actual precipitation distribution.