不同比例尺下DEM的地形特征空间自相关性差异——以川渝地区和长三角区为例

摘要

This research used Local Moran＇s I model to analyze the differences of spatial autocorrelation with different scales,1∶250 000 and 1∶1 000 000.The test regions are Sichuan-Chongqing area and Yangtze River Delta area.We can see from the result that： In most places of the test regions,lots of the spatial autocorrelation values of elevation and slope under 1∶250 000 scale are distributed in a random phenomenon.It also reflects some information of a more stable terrain feature and kinds of homogeneous plain features at the same time.Because of the different sampling precision,under the 1 000 000 scale,we can recognize the distribution of the basic landform types.However,there still exist characteristics of homogeneous plain in some landforms with this scale.So,it can clearly be seen that different sampling precision directly affects the identification of the landform types,and the information they reflected of the local and regional differences in geography and the humanities are also different.%采用局部Moran’s I模型对川渝地区和长三角区1∶250 000和1∶1 000 000两种尺度DEM以及全国1∶1 000 000 DEM地形信息进行了空间自相关的计算分析与比较,研究发现两种尺度下,高程自相关存在一致性,而坡度自相关差异性较大。1∶250 000地形自相关特性多呈随机分布,反映地势较平稳,具有均质平原特性;而1∶1 000 000由于采样精度不同,其虽能够反映出基本地貌类型分布,但针对不同地貌仍存在均质平原扩散特性。可见,尺度会影响地貌类型的识别,同时也能反映出局地与区域的地理与人文差异。