基于DEM和ETM的腾格里沙漠北缘沙丘形态特征提取

本文以腾格里沙漠北缘为研究区,探索沙丘地貌形态提取方法的可行性研究。首先,利用分辨率30m的DEM数据派生出坡度和起伏度两个地形因子。依据坡度(3°)和起伏度(15m)的提取指标,按照形态特征初步判定沙地和沙丘地貌的边界线。其次,结合数学形态分析法,通过斑块指数值的大小初步确定复合流动沙丘的类型。最后,利用ETM影像的色调、纹理、结构等特征,并结合专家经验知识和野外实地观测,建立腾格里沙漠北缘沙丘地貌特征的遥感影像特征图谱,依据特征图谱进一步确定沙丘的类型。本次研究结果表明：DEM和ETM相结合的方法基本上实现了腾格里沙漠北缘的沙丘地貌形态的提取。提取出的沙丘形态主要有：新月形沙丘和沙丘链、线性沙丘,纵向沙垄、新月形沙垄、复合型沙丘及沙丘链、金字塔形沙丘及沙丘链。

Dunes distribution study in north of Tengery desert

In this paper,we take the north of the Tengery desert as the research area, with the foundation data of basic geomorphological map and ETM images,based on DEM of the landscape research methods extracting and analysising the dune types in the north of the Tengery desert.Firstly we use the GIS spatial analysis function to quantitative analysis the slope, curvature, fluctuation degree of study area. and obtain the 3d map, slope profile, slope orientation diagram, fluctuation degree profile and curvature chart, Specially the slope profile and fluctuation degree profile relatively accurate and intuitive display landform changes. Secondly we division landform into sand dunes and sand by the boundary of grade 3 ° and 15 meters. Finally we through the map spot method and remote sensing image, combining the expert knowledge, interpretive different sand dune remote sensing spectrum in north of the Tengery desert . We find that the main dune types in north of Tengery desert are barchan and dune chain, grated dune and grated chain ,pyramid dune and dune chain, linear dune, sand ridge, crescent sand ridge, complex sand dune and dune chain. The area of Barchan and dune chain is larger and mainly distributed in the edge of Tengger desert edge. grated dune and grated chain distributed in the north of desert, the area is not large. Linear dunes are widespread distribute in the east of desert. Compound sand dune and dune chain and pyramid dune and dune chain are mainly distributed in the internal of desert.