Integrierte Bewertung von Flächeninanspruchnahme in Stadtregionen
The conversion of non-urban into urban land is a dominant phenomenon of spatial development worldwide. On the other hand, in many urban regions we find a considerable increase in derelict land. The resulting land use patterns create a plethora of consequences and severely affect ecosystem services and quality of life on all levels, local, regional and global: they impact on biodiversity, water balance, air quality and flood retention capacities as well as soil resources and forest ecosystems. In a more indirect but equally unambiguous way, variables such as energy use and climate change as well as economic feasibility of measures and technologies for the preservation of environmental goods depend on urban land use patterns too. However, current land use policies do hardly take account of these problems. It is therefore a central task of environmental research to provide an evaluation of land use transition impacts in particular regions.
This project aims at an integrated assessment of land use change impacts in urban regions across the different areas in which such impacts occur. It will be a particular challenge of research to take account of brownfield developments in the evaluation process in an appropriate way. At the same time, the project strives for the development of a methodology which allows such evaluation. The urban regions of Leipzig (stagnation) and Stuttgart (growth) will be the case study areas for the empirical analysis.
The evaluation and assessment of actual land use changes can draw on existing knowledge and expertise. However, analyses on the impacts of land use change usually are strictly sectoral (i.e. dedicated to a particular impact of land consumption) and also highly sophisticated. On the other hand, an integrative and practically applicable methodology of impact assessment must be comprehensive and as simple as possible:
- The required data base should be comparatively small (as it will be impossible to scrutinize in detail the environmental conditions in each area for which an intervention by land use policies is intended).
- The assessment procedures should be straightforward, easy to manage, and applicable in different contexts and situations.
The figure (right) illustrates the general elements of the required methodology. The starting point is the available land use data which allows calculating the actual amount of different types of land use transition in a particular (case study) area. The resulting data on actual land use transformations serve as the basis for the calculation of the various impacts of these land use transformations. Hence, certain rules (i.e. equations, algorithms) will be applied to the land use transition data in order to derive the respective impact. The next step pulls the information on these impacts together − for instance by filling this information into a common matrix (synopsis). This opens up the opportunity for an integrated impact assessment across the different impact dimensions that were calculated − for instance by standardizing the impact values according to a common ordinal scale or by applying a cost-benefit analysis. Finally this will allow to make recommendations for land use policy concerning for instance particular sensitive areas or particular questionable types of land use transition.