Automated generalization of buildings and settlement areas for medium scale topographic maps in an object oriented geographic information system environment

Modelling and communicating geographic reality at different scales and themes for differentpurposes are among primary goals of cartographic discipline. Therefore, generalization hasbeen popular research topic for researchers in cartography and geospatial informatics. Inrecent years, it has gained new dimensions together with both massive use of geographicinformation systems and widespreading of map-based web and mobile technologies.Researchers and technology providers make intensive efforts to find a satisfactory automatedsolution to that difficult problem.Cartographic generalization has been made by experienced cartographers in many agenciesuntil today. However, due to the reasons such as high production costs, updating and revisionproblems, the activities for national, regional and global spatial data infrastructures,increasing demands of society for geographic information and maps, it is adopted by nationalmapping agencies that the idea of constructing one master spatial database and deriving manyother products from that database via generalization.In this study, it is aimed at developing automated generalization solutions for buildings andsettlement areas in deriving medium scale topographic maps and cartographic databases frommaster (base) geographic database, regarding short and long term requirements in our country.For this purpose, first topographic data were modelled within object-oriented geographicinformation system and map production software Laser-Scan LAMPS2. After that, a strategybased on Voronoi polygons were developed which strengthens contextual generalizationmechanism. Later, processing steps for generalization were determined, besides somealgorithms were developed in addition to existing ones and, parameters used in algorithmswere statically determined or dynamically computed by iteration. All processes wereautomatically implemented by means of KartoGEN generalization interface and methods indatabase level developed in this study using Lull programming language. It concluded with acase study for cartographic generalization of medium scale topographic cartographic data setand an evaluation of obtained results.Keywords: Cartography, geographic information system, generalization, topographic map,object-oriented spatial databaseii