1st EARSeL Workshop of the SIG Urban Remote Sensing Humboldt-Universität zu Berlin, 2-3 March 2006 1 ANALYSING A REVERSE DEVELOPMENT OF OPEN SPACES AND DENSIFICATION IN THE (SUB)URBAN GRADIENT - A GIS TOOL WITH REMOTE SENSING AND VECTOR DATA - Ellen Banzhaf 1 , Volker Grescho 1 2 1. UFZ – Centre for Environmental Research Leipzig – Halle, Department Urban Ecology, Envi- ronmental Planning and Transport, Leipzig, Germany; ellen.banzhaf@ufz.de 2. University of Applied Sciences, Institute of Construction Engineering and Surveying, Neu- brandenburg, Germany; volkergrescho@gmx.de ABSTRACT Tremendously high dynamics of urban development where growth and shrinkage processes occur at the same time and can recently be observed in cities of many Central and Eastern European countries. Suburbanisation is going along with an expansion of residential and commercial areas at the urban fringe. In this particular case it is simultaneously observed and interacts with an overall declining population and a stagnating economy as a consequence of de-industrialisation (i). As a diverging development inner cities with their compact urban form suffer from this decline in popula- tion density and are affected by an increase of residential vacancy as well as commercial brown- fields (ii). In this context the gradient from the central urban area to the suburban region is focused to find specific indicators characterising this phenomenon. Such indicators comprise land use changes as well as changes in population, commerce and employment even on the smallest ad- ministrative unit (iii). In the developed methodology statistical information from all administrative districts, classification and spatial change detection for pervious and impervious surfaces derived from remote sensing data between 1994 and 2005 are analysed. Goal is an instrument to support evaluation procedures for collaborative authorities to judge where and how fast open spaces come into existence and which densification tasks or open green management should be undertaken (iv). The analysis aims at highlighting the development potentials of the whole regional gradient without the limitation of single administrative boundaries. Therefore neighbouring local authority areas can make use of the instrument. INTRODUCTION Landscape fragmentation is regarded as one of the most urgent problems of urban development (v). Urbanisation is related to multiple issues of global change like changes in economic, social, and also spatial structures going along with environmental conditions. Facing the structural change from industrialised to service-oriented and information-based society, current urban functions are a continuous process of decline and reorganisation or revitalisation. Driven by an increasing demand for living space, an augmenting number of single-person households, a higher mobility and recrea- tional requirements the urban population has an expanding need for settlement and transport spaces. This development parallels to the rising land use claim for commercial and industrial sites. With regard to the national sustainability strategy 2002 (vi) a goal was formulated to reduce land use demand from presently 105 ha to 30 ha per day in the year 2020. The strategy of urban plan- ning is to pursue a so-called double interior development in order to provide a rather compact city with revitalisation through re-use of demolished sites plus open spaces for recreational facilities. The redevelopment of inner urban derelict land for temporal and even long-term renaturalisation of