Abstract. 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.

<p><strong>Abstract.</strong> On the judicial basis of § 196 Baugesetzbuch (BauGB, 2018) every municipality in the Federal Republic of Germany must publish standard land values in €/m² for its whole district area in a biennial cycle. The standard land values have to be derived comprehensively for different land use categories within this district. With the help of Geographic Information Systems (GIS) all the necessary data for the derivation of the standard land values can be analyzed. This data consists of cadastral information (ALKIS) (AdV, 2008) for each municipality district like streets, buildings, land parcels, areas of application for special building law as well as geocoded data about purchasing prices within the district’s real estate transactions. The following work contributes to both requirements, the statutory determination of the standard land values answering the legal necessity and the setting up of the generated geo data in the Web according to the transparency demanded by the European INSPIRE (Infrastructure for Spatial Information in Europe) directive. This report describes the implementation of the automated process of the setup of the relevant data layers based on ALKIS data in an Open Source GIS (QGIS) using SQL and Python scripts. The standard land values are visualized and presented in a Web GIS. After the evaluation of different alternatives, QGIS Server and Lizmap, an Open Source QGIS Web Client, were used for the web based presentation and accordingly configured.</p>

Abstract. In recent years, efficient management of urban spatial data has played a major role in improving urban planning projects both in terms of cost and time savings. Since urban planning projects involve various disciplines like city planning and architecture as well as working with different spatial data, one of the main challenges is how to integrate and manage these multimodal data for a proper workflow. Currently, the involved companies are using project management and accounting systems, so called Enterprise Resource Planning (ERP) systems to handle these complex urban projects - that partly handle the same data objects as stored in urban spatial databases but without any spatial reference. Embedded in the application example of an urban redevelopment area, which according to the German Urban Development Promotion Act aims at financially promoting urban districts in need of renewal, project-related spatial and non-spatial data that were previously kept separate are linked and integrated. Therefore, our work presented here bridges the gap between these two types of application systems, the non-spatial accounting system called Finanz Management System (FMS) and the urban spatial databases. FMS manages information related to parcels, buildings, property owners, as well as the legally required payments connected to urban development, while an urban spatial database manages the geodata. We describe the prerequisites, procedures, and software development steps for coupling different types of applications by providing an example of the Enterprise Application Integration System (EAI). Our innovative integration process aims at making information from the spatial database available in FMS and vice versa, and allows updating the corresponding databases. Our work shows the potential of open-source software for cadastral data processing and visualization as well as accounting procedures for urban planning projects.