中国陆地地貌基本形态类型定量提取与分析

中国陆地地貌基本形态类型由海拔和地势起伏度两个指标组合划分而成,其中海拔分4级,地势起伏度分7级,组合后的基本形态类型共25类。按照数字地貌分类体系,海拔和起伏度拥有全国普适性的分级指标,基于DEM数据可获得两指标的分级类型。试验表明,基于SRTM-DEM(水平分辨率90m,相当于1:25万比例尺)数据可得出全国普适性的采用单元为4km²,利用1:10万、1:400万等比例尺数据进行DEM试验,得出我国存在0.4、4、12、18、21km²五种不同规模的采样单元,并分别对应着不同的比例尺。因我国地貌复杂多样,仅利用DEM数据所获得的海拔和地势起伏度分级数据不能完全反映不同地域的地貌特征,故利用遥感等多源数据,综合多种信息获得的地貌类型,可很好地反映出我国的海拔4级分级特征和地势起伏度7级空间分布,进而获得全国陆地的25种基本形态类型的面积及空间分布格局。

Quantitative Extraction and Analysis of Basic Morphological Types of Land Geomorphology in China

Basic morphological types of land geomorphology in China are made up of two indexes： altitude and relief amplitude.The altitude index is divided into 4 classes,that is： low altitude 1 000m,middle altitude 1 000～3 500m,high altitude 3 500～5 000m,highest altitude 5 000m;relief amplitude is divided into 7 classes,that is： plain 30m,tableland 30m,hill 200m,low relief mountain 200～500m,moderate relief mountain 500～1 000m,high relief mountain 1 000～2 500m,highest relief mountain 2 500m.Then,the combined basic morphological types are 25 kinds.According to classification system of digital geomorphology,the classification indexes of altitude and relief amplitude are suitable for the whole Chinese continent;the above classified types from these two indexes can be calculated by means of multi-source data,such as DEM,Landsat TM/ETM etc.The experiments show： based on DEM data（such as SRTM-DEM 90m,equivalent to the scale of 1∶ 250 000）,the adopted sampling unit which can be suitable for the whole Chinese continent is 4km2;corresponding to different scales respectively,5 types of sampling units,that is： 0.4,4,12,18,21km2,existing in the whole Chinese continent,can be attained by calculating form DEM data at different scales,such as 1∶ 100 000,1∶ 4 000 000 etc.Because of the complexity and multiplicity of Chinese geomorphology,the geomorphologic features of different regions can not be only reflected by means of elevation value and relief amplitude acquired from DEM data;hence,based on multi-source data such as remote sensing,the spatial distribution of 4 classes of elevation characteristics and 7 classes of relief amplitude characteristics in China can be well represented by means of the geomorphologic boundary acquired from artificial virtual interpretation;furthermore,the area and spatial distribution pattern of 25 kinds of basic morphological types of land geomorphology in China are achieved.