天津降水数据的空间插值分析

Spatial Interpolation Analysis of Tianjin Precipitation

采用反距离加权法（IDW）、梯度距离平方反比法（GIDW）、普通克里格法（OK）、协同克里格法（COKRING）插值方法,对天津市及周边地区四种频率年平均最大一日暴雨量数据的空间插值精度进行对比研究.交叉验证表明：四种频率降水量的插值平均绝对误差（MAE）为：15.77mm、18.42mm、11.71mm、11.72mm;平均均方根误差（RMISE）为：22.02mm、33.29mm、19.43mm、19.71mm;插值精度排序为OK〉COKING〉IDW〉GIDW;OK与COKRING差别并不明显,GIDW精度远低于IDW;降水频率的高低影响插值的误差,二者呈显著负相关关系.天津一日最大暴雨量的空间分布特征为：由北部山地和东南部沿海向中部地区逐渐减少.

Based on the four frequency 80 years average rainstorm data of Tianjin area,four methods,viz anti distance weighted（IDW）,Gradient inverse square distance（GISD）,Ordinary Kriging（OK） and Collaborative Kring（COKRING）,were used to interpolate.The results of cross-validation showed that average absolute error （MAE） of the four frequency precipitation interpolate were 15.77mm,18.42mm,11.7175mm,11.7225mm respectively.Average root-mean-square error were 29.4mm,45.61mm,26.27mm,26.67mm severally.Generally,the precision sort was in the order of OKCOKINGIDWGIDW.In terms of the correlation between precipitation,attitude,latitude and longitude was weak,there was no significant difference between OK and COKRING results,and the accuracy of GIDW was much lower than that of IDW.The precipitation frequency was negative correlation with the interpolate error.The spatial interpolation results show that：the space distribution feature of the rainstorm in one day of Tianjin is gradually reduced along the way from the northern mountains and south-east coast area to the central region.