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Sustainability Barometer of Urban Land Use

Forschungen 130, Eds.: BMVBS/BBR, Bonn 2007

Project management BBR: Dr. Fabian Dosch fabian.dosch@bbr.bund.de

Abstract

The land-saving development of newly urbanised areas has been one of the even legally demanded aims of regional and urban planning policies for quite a long time; yet only in recent years this issue has been paid attention to both in the public and in politics. Particularly the objective of the National Sustainability Strategy to reduce land consumption to 30 ha/day until 2020, set off an intensive and quite controversial discussion.

By international comparison, Germany has a good data basis for soil and landscape protection. Yet the official land statistics working with only rather approximate data are inadequate for the complex problems of indicating costs and benefits of land consumption and the relating information requirements by politicians and scientists. So far, for example, it has not been possible to develop effective monitoring or controlling instruments providing reliable information on the quantitative or qualitative development of land consumption and urban form.

With this in mind, it is the aim of this research project to establish an indicatorbased information and assessment instrument - called "sustainability barometer" - by which the present land-use and its changes can be assessed on the federal, the State and the regional level. This sustainability appraisal method is an attempt at systematically widening the informational basis of land-use related policies. The transition from administrative land-use statistics with a quantitative-descriptive orientation to a GIS-based observation of urban land-use and land-use change is to be achieved by an integrated quantitative-qualitative goal and evaluation framework.

The "sustainability barometer" is an information and assessment instrument to support political decisions and policy evaluations for controlling land consumption by new settlements and transportation infrastructures. It consists of three closely linked components - a system of targets, a relating system of indicators, and a quantitative index generation procedure allowing for an overall decision-oriented assessment of land-use and its changes (compare figure). By different methods land-use indicators can be aggregated to a sustainability index. The appraisal approach can be applied on different administrative levels above the municipal level (counties, states, country) as well as for non-administrative spatial units (such as grids or landscape units such as catchment areas for water bodies or soil areas).

The indicator system distinguishes between a static and a dynamic perspective. The static perspective indicates "macro qualities" of urban land-use and land-use patterns at either a predefined point of time or at different points of time. This kind of investigation usually works with highly aggregated data (e.g. the current amount of urbanised land, the number and spatial extent of large undissected open spaces); their temporal variability, however, is rather restricted. Although it is possible to measure the time-dependent changes of macro qualities of land-use, this kind of information is of only minor relevance for evaluating political actions, since their actors require a rather immediate feed-back on the efficacy of certain measures.

The static perspective is therefore supplemented by a dynamic one focussing on those land-use changes that can be recorded within one accounting time period. In contrast to the aggregated approach, investigations on these changes are partly based on disaggregated data focussing on site characteristics of single land-use changes (e.g. the topological and acceptor-specific characteristics of new development). While the static perspective supports higher-ranking political assessments of urban land-use and land-use change, the dynamic perspective rather establishes the contents of operative political actions on project level.

Starting point of developing an indicator system focussing on urban land-use issues is the settlement-policy target of a sustained, i.e. environment-friendly, socially just and economically sound form of land-use pattern. The "sustainability barometer" distinguishes between four types of targets:

  • Reduction targets: These comprise all those targets referring to the quantitative reduction of land consumption for urban uses irrespective of the question what areas are affected by what qualities.
  • Protection targets: These refer to the protection of environmentally valued ecosystem components and open spaces and the land areas sustaining them.
  • Urban form targets: These subsume targets referring to the development of land-use patterns and the spatial integration of newly urbanised areas within the context of existing land-use patterns. By comparison to reduction targets, urban form targets rather focus on the configuration than on the composition of urban land-use patterns.
  • Efficiency targets: These refer to the degree of economic efficiency regarding urban land-use. An efficient land-use is characterised by maximising economic and social benefits while minimising environmental and social costs associated with urban land uses.

By various procedures, the indicators' measurement results can be aggregated to a sustainability index. Three methods for generating this index have been proposed or tested: a spatially generated index, a temporally generated index, and the application of indicator-specific transformation functions, well known in quantitative assessment tools like cost-benefit analysis. The indicator generation process is carried out separately according to those indicators that represent the land-use pattern (static perspective) and those parameters that measure land-use changes (dynamic perspective). This approach appears to be the best for detailed information on the state and the changes of land-use patterns.

Components of the "Sustainability barometer" of urban land use

Components of the "Sustainability barometer" of urban land use


The abstract is part of the German publication "Nachhaltigkeitsbarometer Fläche - Regionale Schlüsselindikatoren nachhaltiger Flächennutzung für die Fortschrittsberichte der Bundesregierung", Forschungen 130, Hrsg.: BMVBS/BBR, Bonn 2007 - out of print
ISBN 978-3-87994-462-0, urn:nbn:de:0093-FO13007R150