Study On Cartographic Generalization For Building Present Land-used Database From 1:10000 To 1:50000

The current land-use database is a thematic database which can record and express the status land use data detailedly for the research area,and is also the scientific basis of formulating plans for national economic and social development,managing land resources rationally for different relevant departments.Different policy makers often need different scales of land-use status data, and the detail of county level is 1:50000 as a general rule.At present, we can digitizate and update the original paper map to establish county level land-use spatial database at detail of 1:50000, in addition we can also use the cartographic generalization technology to compress the land-use status database(1:10000).In this paper, we make the land-use span and linear features as the research object in 1:1 million current land use database of Huxian.In this research,we base on the standards of county level land-use database and the technical specification of downsizing the second national land-use survey data(trial),we use computer and GIS technology to establish generalization rules of current land-use database at the county level 1:50000 from following aspects,such as importance of the tpye of land-use,setting the threshold,selectting the land objects,maintaining the correct topology relationships. Following the above rules, we use the ArcGIS tool to generalize the current land-use database at the county level 1:10000. Finally,we evaluate the database from several aspects,such as the topological consistency, weighted center stability, structure similarity,layout semantic similarity. Among them,the structural similarity index of the overall land-use spot is 0.9366, layout stability index is 0.9135, semantic similarity is as high as 0.9968.The results in this paper prove that the database generalization method is reasonable and feasible.