1：1000000中国草地资源图的编制与研究

THE COMPILATION AND STUDY OF THE GRASSLAND RESOURCE MAP OF CHINA ON THE SCALE OF 1:1000000

编制１：１００００００中国草地资源图（以下简称《草地图》）是＂１９７８～１９８５年中国科学技术发展规划＂中的一项重点研究课题。首先在全国约８００万ｋｍ２草地分布区的２０００多个县内进行野外实地调查和产草量测定，辅以航、卫片校核，编绘县级１：５万或１：１０万草地类型图、草地等级图、草地利用现状图。然后采用系列制图方法，遵照全国统一的编制规范和制图综合原则，用上述县级草地图逐级缩编成国家级１：１００万草地资源图。该图在不同的制图区域──牧区、半农半牧区、农区有不同的地理要素选择标准；不同的图斑表现级；不同的最小图斑面积。《草地图》除传统地表现草地植被类型外，还表现草地利用性状，按制图单元进行草地等级评价。用变距等高距选取了少量对划分草地类型界线、重要牧草分布界线、季节草地界线有重要指示意义的等高线。

The compilation of the grassland resource map of China (GRMC) on the scale of 1: 1000000 is one of the key research projects of 'The Science and Technology Development Program of China of 1978￣1985' .At the first stage of compilation, various grassland resource maps on the scale of 1 : 50000 or 1 : 100000 are maded at the county level. This work covers about 8000000 km2 and includes more than 2000 countries in the grassland areas of China. The maps are made by airphotos, MSS image interpretation and the topographical maps on the scale 1 :50000 or 1: 100000 (used as the base maps) . The field work is carried out for measuring the yield of grassland. At the second stage, the scale of the maps is reduced step by step by using the method of series mapping, according to the principles of the synthctic of mapping and the national unified standard of compilation. The GRMC has different choice standard of geographical elements, different expressional grades of map spot and different smallest area of map spot in the pastoral areas, the semi-agricultural and semipastoral areas and the agricultural areas.The GRMC traditionally expresses the vegetation types of grassland. Bisides, it cxpresses the present characteristics of grassland utilization and the grassland class evaluation based on mapping units. A few contour lines which have significance to delineate the grassland types, the distribution of herbages and the seasonal grassland are chosen by using different contour intervals.