AMMI模型的DEM内插方法不确定性研究

内插模型的精度评价问题一直是DEM内插研究中的热点问题.以往较多的研究关注插值模型本身的精度评价,却忽略了插值模型与应用环境之间的交互作用,例如,普通克里金方法作DEM内插一般精度较差,但是当插值区域平坦时,该方法的插值精度却很高,这表明该方法对平坦地形的插值问题具有较好的适应性.为了分析不同插值模型在不同地形环境下的适用性,本文选取陕北黄土高原地区不同地貌类型的实验样区,应用AMMI模型对不同内插模型的精度,以及对不同地貌类型的适用性进行评价,该模型最大的特点是很好地结合了方差分析与回归分析的特点,特别适合于不同影响因素之间交互作用的分析.实验结果表明,AMMI模型可以有效地分析内插方法与地貌环境对内插精度的交互作用,不同的内插方法对不同的地貌类型区的适用性存在差异.以本文的研究为例,在陕北黄土高原地区最稳定的DEM内插方法是样条函数法,而反距离加权法与Top to Raster方法精度会更高.最后,通过对环境指数与若干地形因子的相关性分析,表明地貌类型区的坡度可以粗略地代表第一环境指数.

Uncertainty Analysis of Different DEM Interpolation Methods Based on AMMI Model

Analysis of evaluation of interpolation models is a hot topic in the DEM interpolation studies.Most studies focused on the interpolation model in the last decades,while ignored the influencing factors between the interpolation models and environments.That is to say,on the one side,different interpolation models influence the accuracy of the analysis result;on the other side,difference environments also influence the accuracy of a certain interpolation model.In order to analysis the applicability of different interpolation methods in different environments,this paper selected test areas under different geomorphic types,and used the AMMI model to analyse the accuracy of the different interpolation models and the applicability of the studied models to different geomorphic types.The experiment results showed that the AMMI model could test the influencing factors between the interpolation models and the environments.Taking the test of this paper as an example,in the Northern Shaanxi region,the ordinary Kriging model is the best choice in the DEM construction.Finally,by analyzing the correlation coefficient between the environment coefficient and several landform parameters,it can be found that the slope gradient could represent the first environment coefficient.