Land is one of the natural resources, which is irreplaceable for all demands of life, urban and rural development as well as agricultural production. But the efficiency of land use is already very low and furthermore decreasing and so the deficit concerning sustainable land use will be also declining. During the last years urban expansion and the development of settlement areas have been the driving forces of an enormous land consumption, the usage of natural resources and the loss of ecosystem services. To realize this urban planners have to focus on an inbounded and concentrated settlement development characterized by additional densification of built-up areas and land recycling of brownfields. The current trends of outbounded settlement development and an increasing urban sprawl have to be stopped for the sake of a sustainable settlement development.

The elaboration of a multicriteria assessment scheme (MCA) for suitable housing land potentials under the premise of sustainability shows are many technical and structural requirements on indicators and criteria. These requirements significant determine the applicability, transparency and communicability of such a MCA-approach. Technical influences such as the availability of data essentially determine the choice and applicability of the indicators. The more, to ensure an integration of the MCA into current planning processes addressing issues of sustainability it is of great importance to  keep   the  demands  and   decision   processes   of   future  users

 (municipalities and local decision-makers) in mind.

Based  on  this  the  focus  has  lie on local  models to reduce an

58

often fairly high level of abstraction and to achieve a direct and comprehensible reference to land. A comprehensible MCA-scheme is an important step towards a transfer and  communication  of  scientific

knowledge into local assessment and land management approaches. In addition, such an approach requires a scientifically consistent design but has to bridge the gap towards municipal planning practice and subsequent user-friendliness. The synthesis of a consistent and scientifically representative MCA-scheme towards an applicable, decision- and policy relevant assessment framework for municipal planning is a crucial task of the presented approach.

Beside structural determinants we have to face concrete practical technical requirements influencing the MCA-design and selection of indicators. These requirements related to available data-sets especially determine the characteristics of indicators (qualitative/quantitative) and their spatial application. As a consequence these aspects such as quality and availability of data have crucial influence on the main focus of the MCA-scheme. These constraints limit a scientifically consistent operationalisation of sustainable settlement development but are limiting factors scientists have to be aware of.

Finally, these requirements are resulting in three priority tasks which the presented MCA-scheme has to fulfil:

• Deduction and thus operationalisation of complex system- interrelationships to provide a broad understanding of practitioners and to allow its communicability (analysis function).

• Reduction of complexity and information to depict reality (communication and information function).

• Control, warning and decision-making function: Within the planning process a sustainable regional development can be partially controlled using appropriate indicators. Planning alternatives can be evaluated based on an assessment framework using MCA.

   • Monitoring function: A target-performance comparison of different planning scenarios allows a monitoring of human settlements development using sustainability indicators. With the help of appropriate indicators sustainable settlement development can be depicted and becomes measurable (decision, controlling, monitoring).

Indicator values of the status-quo and future development scenarios can be compared, measured and assessed using threshold or reference

59

values.

Exercises