DEM分辨率对地形因子提取影响的研究

Study on the Effect of DEM Resolutions Extracting on the Landform Factors

以大兴安岭漠河地区1∶5万比例尺的等高线数据为研究对象,生成不同分辨率的数字高程模型(DEM)数据,分析在不同分辩率条件下,由DEM提取的坡度、坡向及剖面曲率随分辨率的变化情况,并利用信息熵公式进行不同分辨率DEM高程熵分析,得到高程熵随分辨率的变化趋势。结果表明,当DEM分辨率达到25 m左右时,各地形因子的变化情况趋于稳定,分辨率达到50 m以后变化明显加剧。高程熵在分辨率增大到25 m时变化减慢,据此判断,漠河地区1∶5万比例尺等高线在生成DEM时最合适的分辨率应该是25 m。

The 1：50000 contours data of Mohe area Daxingan Mountains was used as the objective to generate different resolution Digital Elevation Model （DEM） and analyze the changes of slope,aspect and profile curvature under condition of the different resolution DEM.The change trend of DEM height-entropy with different resolution was also analyzed.The results showed that the changes of each topography factor became stable when the DEM resolution came to around 25 meters and the change became apparently intensive when the resolution came to over 50 meters.Height-entropy changed slowly when the resolution enlarged to 25 meters.It was concluded from above results that the most appropriate resolution should be 25 meters in the Mohe area when 1：50,000 contours was used to generate DEM.