Because objects are often portrayed differently in maps of different scales, it is a complicated process to produce multi-scale topographic maps that meet specific cartographical criteria.In this study, we propose a new approach to update small-scale maps based on updated large-scale maps.A brief description on propagating updates among multi-scale datasets in MRDB is given here because it is fundamental to understand our following work.Key inputs to propagating updates of residential areas from larger-scale to smaller-scale maps include the in the large-scale maps, which will be propagated to objects in the small-scale maps, generally include attribute updates (e.g., land use types, household ownerships) and geometric updates [16,17,18].
A possible way to enhance the updating efficiency is to first group the updated large-scale objects and then operate them together for updating the corresponding small-scale object, such that all updated large-scale objects can be processed together, making the updating procedure parallel.
Mapping agencies, such as the National Administration of Surveying Mapping and Geo-information in China, produce and maintain large amounts of topographic maps and geospatial datasets that characterize the same geographic areas in varied themes and at different scales.
For areas that experience massive land-cover and land-use changes, for example South China where rapid urban expansion has taken place during the past few decades , timely updates of topographic datasets, especially buildings and roads, are required to support a number of downstream applications, such as land use monitoring, natural resource management, road construction, and urban planning [3,4,5].
Updating topographic maps in multi-representation databases is crucial to a number of applications.
An efficient way to update topographic maps is to propagate the updates from large-scale maps to small-scale maps.