| Landform is one of the most important components of physical environment. To some extent, it controls the distribution and variations of ecological and environmental pattern on the earth surface. Geomorphologic mapping is an important method of regional geomorphology research which can be used to demonstrate geomorphology research result. As maps are thought of as the Second Language of Geography, the geomorphologic maps play an important role in agriculture production, ecology environmental protection and national defense etc... Traditional geomorphologic mapping method mainly depends on handwork and field surveying. Usually, we geologists get geomorphologic mapping information from large-scale topographic maps, then make the transitional maps by means of mapping synthesis, and add various mapping contents to these maps. Especially, in areas with indefinite geomorphologic boundary, field surveying should be carried out to complement this work. The result of this mapping method is more accurate than others', but this method needs enormous human work and takes more time. Therefore, this method does not meet the needs of information age. As the technologies of RS and GIS develop, more and more geomorphologic mapping work can be finished by means of the Remote Sensing data indoor in shorter time nowadays. With the carrying out of the geomorphologic mapping of 1:1,000,000 in China, it is necessary to find out a new and uniform numeral geomorphologic mapping method.Therefore, this research takes J-48 as research area which has various geomorphologic types with the intention of getting one new geomorphologic mapping method based on Remote Sensing and DEM which can be used as the foundation of nationwide geomorphologic mapping of 1:1,000,000 in China. The basic data of the research includes the historic geomorphologic maps, DEM of 1:250,000 and ETM+ images (combination with 7,4, 2 bands) of 2000. The operation was carried out in the ArcGIS8.3 software. The steps of this mapping method as follows: (1) getting the topographic characteristics by using the DEM to count the elevation, relief amplitude, three-dimension, contour, gradient and hillshade of research area;(2) taking the geomorphologic boundary of historic geomorphologic maps as quantitative or qualitative symbols;(3) using hue and veins demonstrated in the remote sensing images as quantitative indicator. This method integrates Remote Sensing, Geographical Information System (GIS), Geomorphology and Mapping to explain various geomorphologic boundary of research area. This method not only inherits the research achievements of traditional geomorphologic mapping, but also makes use of the advantages of DEM and Remote Sensing. Its purpose is to deeply dig the geomorphologic characteristics, which hide in Remote Sensing images by using physicalgeography knowledge and other auxiliary dates. This mapping method effectively reduces unnecessary field surveying, and geomorphologic mapping can be easily finished in shorter time. Therefore, the method not only can improve work efficiency of geomorphologic mapping, but also reduce the labor intensity of the researchers. What is more important is that it realizes the digitization of geomorphologic maps.Moreover, since 1950s the geomorphologic research has gradually transited from traditionally qualitative description to numerical analysis and quantitative research. However, because of the numerous data and the cumbersome calculation, quantitative geomorphologic research developed very slowly. Just with the rapid developing of GIS technology, it is possible for us to manage, analysis, and calculate the numerous data. Therefore, with the same research method of digital geomorphologic mapping in J-48, we carried out research on the fluvial morphotectonic features in eastern Qilian Shan based on Hack profile and strahler curve of five rivers in this area through the application of 30-meter resolution DEM. This research not only validates a new way studying fluvial morphotectonic features, but also offers a new integration between GIS technology and traditional geomorphology.
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