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1 2009

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Analiza spójności modeli pojęciowych polskich urzędowych baz danych referencyjnych

Głażewski A.

Roczniki Geomatyki

2009

T. 7, z. 5

55-77

In the paper, results of coherence analysis of conceptual models of Polish reference databases accessible in the state geodetic and cartographic resources are presented. The databases examined constitute basic elements of the Polish NSDI, and their conceptual models are referred to three scale levels: m Cadastral ~1:1000, m Basic topographic ~1:10 000, m Generalised topographic ~ 1:50 000, The conceptual model of spatial database, determining its content, defines abstractions of real phenomena . database entities . by means of definitions of features, names of attributes, data types, and types of links between feature classes. At this stage, choosing the way of referring the entities to phenomena of geographic reality is of key importance. In the theory it is assumed that database utilization and case studies determine the way of abstracting basic features of geographic space-time. Modeling of the same phenomena may give different (correct) results . depending on the aim the database is used. Sometimes it.s necessary to preserve redundancy of data at the highest levels of detailness (named here: cadastral and basic topographic) by saving several versions of the same phenomena . referring to different features (eg. object.s axis and its face). The starting point for research was the concept of Multiresolution Topographic Database (WTDB), worked out within the Project No. 6 T 12 2005C/06552 .Methodology and procedures of integration, visualisation, generalisation and standardisation of reference databases, which are accessible in official geodetic and cartographic resources, as well as their utilisation for development of thematic databases.. The project was led by the Wroclaw University of Environmental and Life Sciences in cooperation with the Department of Cartography of the Warsaw University of Technology. The TBD database (or the TBD2) is to be the basic source of data for the WTBD; for areas, which have not been covered by that database . the VMap L2 or the VMap L2+ should play that role. Other databases which are accessible in the official resources of geodetic and cartographic data, and, first of all, the State Register of Geographic Names, the State Register of Borders and cadastral databases should be considered as auxiliary data. This concept assumes applying the Multiresolution Database (MRDB) model, database saving features referred to several scale levels. The problem of coherence of conceptual models of Polish official reference databases is exemplified here by three groups of topographic phenomena: buildings and built-up area, road network and river network, which are the most important elements of topographic description of reality. The results are evident: harmonisation of databases, referred to different scale levels, is possible only within the NSDI components which refer the conceptual models to TBD model. The harmonization process, leading to database coherence, makes it possible to have data flow, data acquisition for generalized models, interoperability, common analysis and visualisation.