数字地价模型建立过程中的插值方法研究——以上海内环线地区为例

A study on interpolation techniques in the Digital Land Price Model——the case of Shanghai inner belt-way district

对反距离加权平均(IDW)插值法和克立格(Kriging)插值法两种空间插值方法在数字地价模型(DLPM)建立过程中的插值效果进行比较研究,采用上海内环线地区内的实际样本点数据进行有关实证分析。利用空间插值软件Surfer8.0对上海内环线地区内地价样本点使用上述两种不同的插值方法插值生成不同的插值结果文件,再利用GIS软件MapInfo7.5把插值结果文件生成数字地价栅格专题图,最后用随机选取的验证点对不同的插值结果进行比较分析。研究结果表明:反距离加权平均(IDW)插值法比克立格(Kriging)插值法插值效果更佳,其插值结果更加接近实际地价分布,而且,反距离加权平均(IDW)插值法属于确定性插值法,也简单、易操作,样本点处的插值结果也可以更好的接近样本点的实际地价值,使得数字地价模型(DLPM)的建立更加可靠、可行。

Two spatial interpolation methods, IDW and Kriging, are studied and their differences are compared in terms of the process of setting up the Digital Land Price Model. A corroborative analysis was carried out using the sampling data in the area of the Shanghai inner belt expressway. The two methods are applied using a Surfer8.0 software system, based on the land price sampling data of the aforementioned area. The results are then used to obtain the digital land price grid subject charts with the help of the GIS software, MapInfo7.5. The stochastic validation points are selected to compare and analyze the results, which prove that the IDW interpolation method is better than Kriging and correlate closer to the practical land price distribution. Furthermore, the IDW interpolation method is a deterministic method and easy to use in practice, and the interpolation result at swatch point is close to the practical price, making the process of setting up the Digital Land Price Model more credible and feasible.