USING THE SYNERGY OF QFIELD FOR COLLECTING DATA ON-SITE AND QGIS FOR INTERACTIVE MAP CREATION BY ALKIS® DATA EXTRACTION AND IMPLEMENTATION IN POSTGRESQL FOR URBAN PLANNING PROCESSES
The German law concerning Urban Development Promotion (Städtebauförderungsgesetz; StBauFG) is an important component of the Building Law (Baugesetzbuch). It enables municipalities to be financially supported by the federal and provincial governments for promoting urban development in downtown areas being in need of renovation, maintaining historical centers, or enhancing the value of socially imbalanced areas. Therefore, the law plays an important role for the economical, ecological, social and cultural status of cities. If an urban renovation area is formally declared the reconstruction measures taking place there lead to an upgrading of the real estate land values. The present work contributes on one side to the initial phase for the declaration of an urban renovation area and on the other side to the final phase comprising the legal accounting procedure. At first, the city planners must document the urban status concerning the structure and quality of buildings, vacancy rate for housing and industry, road condition and numerous other urban quality and structure deficits. To acquire these data, the open-source GIS plugin QField serves as an appropriate and easy to handle tool installed on a tablet for the urban planners to collect the necessary data on-site. The planners can then easily assign defined qualities and states of the objects on a map or edit and comment new objects and attributes. Through automatic updating of these data in the PostgreSQL-database, an interactive map in QGIS will then be automatically created in Python. For the last phase, the legal closure of a declared renovation area, our work supports the analysis and modelling of the relationships in the Authoritative Real Estate Cadastre Information System ALKIS® in order to identify the property owners being charged a so-called balance payment for the upgrading of the standard land values resulting from the applied renovation measures. The work shows the high potential of the ALKIS® data being processed with open-source software like PostgreSQL, QGIS, and QField towards a more effective urban planning.