Ellen Banzhaf

Delineating urban structure types (UST) in a heterogeneous urban agglomeration with VHR and TerraSAR-X data

Due to continuous world-wide urbanization, especially in developing and emerging countries, urban environment represents one of the most dynamic landscapes on earth. The role of human settlements is becoming more and more important in land management, and the various structures of urban areas differ tremendously depending on social and historical backgrounds. So, beyond land-use and land-cover information, it is the urban composition that explains for social disparities, vulnerability to natural hazards, and deficits in urban and regional planning. In this study, first steps are presented towards and urban structural analysis using a multi-sensoral approach. With very high spatial resolution imageries, remote sensing offers techniques well-applicable to measure and monitor intra-urban heterogeneties. Imageries from Quickbird sensor and TerraSAR-X device, Spotlight mode, are taken to delineate field-mapped and well-defined urban structure types (UST). A robust rule base will be built which allows for accurate classifications and interpretation of typical-man-made structures. The most typical structural characteristics of urban regions are alignment and type of buildings, open and green spaces, and transportation network.

Land-Use Change, Risk and Land-Use Management

This chapter focuses on flood risk analysis and risk prevention in Santiago de Chile. It presents a conceptual framework for flood risk analysis in urban areas and demonstrates the utility of a mixed set of methods, including remote sensing and GIS techniques, to improve the methodological basis for flood risk assessment and risk prevention. Population growth and land-use changes are analysed as key elements of urban development and indicators of flood risk production. A conceptual framework comprising the core elements of exposure, elements at risk and vulnerability serves as a tool for risk analysis and risk assessment, and is applied to the municipalities of La Reina and Penalolen. The chapter reviews existing institutional responses to land-use and risk management and, based on expert interviews, detects their deficits. As a conclusion, recommendations to improve flood risk prevention in Santiago de Chile are made. The absence of a systemic view of flood risk resulting from complex ecological and social processes is the chief weakness of current risk prevention in Santiago de Chile.

Flächeninanspruchnahme als Umweltproblem

Die standig wachsende Wohn-, Siedlungs- und Verkehrsflache ist Ausdruck der geseilschaftlichen Lebensweise. Sie macht einen Teil des gesellschaftlichen Naturverhaltnisses aus und stellt eine Belastung fur das okologische System der Erde dar. Dies wurde aber erst relativ spat erkannt bzw. entsprechend thematisiert. Lange Zeit haben vielmehr Themen des Ressourcenverbrauchs (Wasser, Energie, Rohstoffe) sowie Belastungen (Luft, Wasser, Boden) im Mittelpunkt der umweltpolitischen Debatten gestanden. Die Flacheninanspruchnahme war demgegenuber ein vernachlassigtes Thema, ubrigens auch in den Wissenschaften, nicht zuletzt in der Umweltsoziologie. Allerdings lasst sich der Ausgangspunkt aktueller politischer Debatten zur Flacheninanspruchnahme schon fruher, vor allem in den Bemuhungen um den Bodenschutz verorten. So wird bereits in der „Europaischen Bodencharta“ aus dem Jahr 1972 darauf verwiesen, dass die Entwicklung stadtischer Siedlungen so geplant werden musse, damit die umliegenden Gebiete dadurch moglichst wenig Schaden erleiden. Ein dementsprechender Passus findet sich auch in der Welt-Boden-Charta von 1981, in der der Verbrauch erheblicher Bodenflachen fur nicht-landwirtschaftliche Zwecke kritisch angemerkt wurde. Die Bundesregierung zog daraus in ihrer Bodenschutzkonzeption (1985) u. a. die Schlussfolgerung, eine Trendwende im sogenannten „Landverbrauch“ herbeizufuhren.

The influence of urban expansion on the flood hazard in Santiago de Chile

Land-use changes associated with urban expansion frequently lead to an increase of hazards, both natural and man-made [1], [2], [3], [4]. The process of urbanization is often associated with land-use and land-cover (LULC) changes, leading to a reduction of the infiltration capacity of newly urbanized soil. The goal of this study is to analyze the influence of urban growth on the flood hazard in the case of Santiago de Chile. Therefore, the hydrological model HEC-HMS (Hydrologic Engineering Center - Hydrologic Modeling System) is applied to model the hydrologic system at two time steps. The model allows balancing rainfall and runoff with respect to land use characteristics. A comparison with existing flood hazard maps created based on information of previous floods in Santiago can be used for validation. After successful modeling, i.e. representation of the functioning of the river ecosystem, alternative land-use scenarios can be created to predict the influence of urban land-use / land-cover changes on flood hazard. As a first step, the land-use patterns from 2002 and from a comparative date in 1993 have been delineated from high and very high resolution satellite data (Landsat/SPOT, ASTER) using pixel-based analysis. With this methodology, land-use changes of classes with common hydrological properties could be detected and a first quantification could be achieved. Measured rainfall and runoff data for the past 30 years have been analyzed to investigate the changes in precipitation and runoff characteristics. Finally, precipitation and runoff values are related to land-use changes applying the hydrological model. Applying this approach, the influence of land-use types and their spatial pattern on the runoff characteristics in a sub-catchment is investigated. The application of the hydrological model will help to develop scenarios that can be used to estimate the reaction of an urban environment to extreme rainfall and to suggest improved land-use planning in order to mitigate the flood hazard. Future land-use scenarios can be simulated with respect to their influence on the storm water behavior once the model is calibrated.

Databases, data organization and data processing

In the age of transition towards the information society, many different kinds of information and data are being continuously produced and distributed all over the world. Faster computers, the internet, earth observation satellites, and the development of new software and new technologies for various disciplines shape the production, transfer and exchange of information in all spheres of life. Moreover, many questions cannot be solved on a local, regional or national level because they have an international or even global nature. Considering the sheer volume and diversity of information, ever greater demands are being made on the collection, processing, structuring, standardization, sources, accuracy, updating and presentation of data. One general rule is that data collection is very timeconsuming and expensive.

Potenziale städtischer Gewerbebrachflächen für eine integrierte Stadtentwicklung: Monitoring für ein nachhaltiges Flächenmanagement am Beispiel der wieder wachsenden Stadt Leipzig

Abstract Urban brownfields have been an internationally recognised topic for many years and exist in industrialised countries worldwide. After decades of severe shrinkage, Leipzig, Germany, is now a fast-growing city. It serves as an excellent example to discuss the redevelopment of urban brownfields for an integrated urban development. We investigate the potentials of brownfields through land-use monitoring. In our field work, we mapped 783 brownfields in all of the citys commercial zones, including size, geographic position and spatial assignment, land surface characteristics and surrounding infrastructure. Spatial distribution of brownfields in the planning districts as well as land-use pat- terns was of great concern regarding vegetation succession stages and sealed surfaces. Infrared aerial colour photos supported our field information, gathered in a GIS-based information tool of urban districts for the planning division. More than 80% of all derelict land is less than one hectare in size and thus a major challenge in terms of individual recycling. Private ownership hampers redevelopment. Due to advanced succession stages there is a high potential for renaturalisation into coherent green spaces. Pressures on land use demand the readjustment of green infrastructure development in an urban planning masterplan. The project is based on scientific collaboration with the City of Leipzigs Authority of Urban Planning, Germany. English title: Potential Performance of Commercial Urban Brownfield Sites in Integrated Urban Development – Monitoring for Sustain- able Land-Use Management Based on the Ex- ample of the City of Leipzig

Potentials of Urban Brownfields for Improving the Quality of Urban Space

Urban brownfields have been an international phenomenon for decades and are part of most industrialised countries worldwide (de Sousa 2008). Brownfields are understood as previously used land that has been abandoned and may suffer from contamination. They occur in shrinking cities as well as in growing cities. In particular, urban locations that changed from agglomerations with heavy industry to service centres transformed these urban spaces into brownfields. Several international institutions and expert networks deal with concerted actions for brownfields, to develop such valuable urban areas (CABERNET; US Environmental Protection Agency (EPA), European Environmental Agency (EEA), etc.). Despite substantial efforts, many of these previously used industrial sites could not be assigned to new functions and, therefore, no further use was made available. Re-using brownfields can help to reduce the amount of newly sealed land (e.g., Rink and Banzhaf 2011). Land recycling, in particular, is considered a solution because it offers potential sites for residential and commercial constructions (EEA 2015). For the process of reurbanisation, brownfields play a particularly important role in recycling former industrial sites into land that meets the needs of today’s cities. In urban areas, land is subjected to strong dynamics and is a tenuous and competing resource, in view of ongoing global urbanisation. Therefore, the development of commercial brownfields is an important municipal task for sustainable land management. Their potential redevelopment is vital with regard to resource-efficient land management, on the one hand, and the newly developed land-use type as an option for increased urban resilience against natural hazards on the other. Consequently, redevelopment can have marked effects on the quality of life and sustainable urban development (Martinat et al. 2016; Norrman et al. 2016; Bartke et al. 2016).

What Really Matters in Green Infrastructure for the Urban Quality of Life? Santiago de Chile as a Showcase City

The built, green and social environment express the situation of a city and, to a large extent, indicate the development of the urban area. These components of the urban environment have a strong impact on the quality of life of citizens. Along with the concepts of resource efficiency and resilience in cities, the quality of life forms one of the three pillars on which our research on urban transformations is grounded. We approach the concept of quality of life from the environmental perspective and understand the human well-being as an integral part of the broader concept of quality of life. In this study we focus on green infrastructure (GI) as an indication for quality of life research. Here, we measure the extent to which people can access GI as a service and profit from this infrastructure for health-related and social dimensions (Scottish Executive 2005; Bognar 2005). Rapid urbanisation processes accelerate land-use changes that mostly go along with extensive urban land consumption and involve population developments. Such multi-dimensional changes in urban land use and land-consumption patterns are very dynamic and widely ramified. They can evoke unsustainable structures that entangle social-spatial differentiations which are discussed in the context of urban growth and shrinkage processes (see Haase et al. in this volume, dealing with urban dynamics, Seto et al. 2011; Kabisch and Kuhlicke 2014). As land is a limited and contested resource, it demands for infrastructural provision and, particularly with respect to urban quality of life and a sustainable urban development, for the provision of green infrastructure.

Evaluating public green spaces for the quality of life in cities by integrating RS mapping tools and social science techniques

Urban green spaces are essential for the well-being of citizens. We developed a mixed method approach by (1) exploiting RS data to estimate amount and distribution of vegetation cover and (2) conducting a social survey to add in-depth knowledge on accessibility and perception of green spaces. The study area are three municipalities of Santiago de Chile characterized by different household incomes. Existing indicators, such as the amount of green spaces per inhabitant, do not provide enough information for effective decision-making. Our aim was to develop tools to improve planning of location and quality of green spaces in complex urban areas. We apply a set of indicators to disclose existing inequalities. In addition, our in-situ observation on the usage of green spaces and conducted interviews helped to reflect the perception of green spaces by residents.

Derive an understanding of Green Infrastructure for the quality of life in cities by means of integrated RS mapping tools

The provision of urban green areas has long been associated with an improvement of the quality of life in cities. In order to achieve a sustainable urban development for a livable city, it is significant to measure urban Green Infrastructure (GI) at micro-scale level as it provides various urban ecosystem services. Grounded on Object Based Image Analysis we distinguish classes of urban trees and obtain a detailed differentiation of GI in an urbanized environment. Our integrated Remote Sensing mapping tools give a possibility to measure and assess urban GI at more detailed resolutions, and thereafter link urban GI to its functions for a multifunctional GI, through which we can, hence derive a better understanding of the contribution of GI for a better urban quality of life.