基于空间插值方法的中国南方酸雨时空分布格局模拟及分析

酸雨时空动态变化监测一直是环境治理所需的重要信息. 在我国南方酸雨"两控区"(酸雨控制区和二氧化硫污染控制区)1991-2001年酸雨观测站年降水pH数据的基础上,采用反距离加权(IDW)、普通克里格(OK)和基于样条函数的ANUSPLIN等3种方法进行酸雨空间插值模拟,并进行验证. 对比分析了3种方法酸雨插值结果与实测值的统计误差、预测标准误差和相对误差区间分布,以及依据插值结果得出的酸雨分布图层. 结果表明:反距离加权法和普通克里格法仅能反映酸雨水平方向上的分布特点,而ANUSPLIN法由于加入了地形作为协变量因子,可很好地反映酸雨空间分布的地形变异特点,更合理地体现了酸雨时空分布特征. ANUSPLIN法插值结果表明,酸雨严重区主要分布在四川盆地、长江以南广大地区,酸雨强度沿长江向西北及北方地区有不断扩大的趋势.

Simulation and Analysis of Spatial-temporal Patterns of Acid Rain in Southern China Based on Spatial Interpolation

Monitoring information of spatial-temporal dynamics of acid rain is an important part of environmental management. The observed pH of annual precipitation data were collected in southern China within the acid rain and sulfur dioxide pollution controlled areas from 1991 to 2001. Three interpolation methods (IDW, Ordinary Kriging, and ANUSPLIN) were used to simulate the spatial-temporal pattern of acid rain from the collected data. For validating the simulated results, partial observed data were selected as an independent data set. The results of the analysis showed that the IDW and Ordinary Kriging methods only described the horizontal characteristics of the input data, while the ANUSPLIN method reflected the topographical variance of acid rain due to the consideration of elevation as a covariant variance in the interpolation process. The simulated results using the ANUSPLIN method captured the actual characteristics of the spatial-temporal distribution, which showed that the most severe acid rain polluted regions were located in the Sichuan basin and the areas to the south of the Yangtze River. Furthermore, the simulated results revealed a trend of gradual acid rain region expansion from southern China to northern China along Yangtze River.