02 Fakultät Bau- und Umweltingenieurwissenschaften
Permanent URI for this collectionhttps://elib.uni-stuttgart.de/handle/11682/3
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Item Open Access Managed retreat as adaptation option : investigating different resettlement approaches and their impacts : lessons from metro Manila(2021) Lauer, Hannes; Delos Reyes, Mario; Birkmann, JoernManaged retreat has become a recommended adaptation strategy for hazard-prone coastal cities. The study aimed to improve considerations for the contextual factors that influence the success of managed retreat and resettlement projects in Metro Manila. Data were collected through a mixed-method approach consisting of a screening of relevant literature, a qualitative case analysis of resettlement projects, and a workshop series with Philippine stakeholders. It turned out that the resettlement of informal settlers is a central element of urban development. Though in-city resettlement is preferred, the majority of existing and planned projects are developed in off-city locations. The findings present a nuanced view of different retreat approaches. Not all in-city resettlements are successful, and the unpopular off-city projects have a potentially important role for urban and regional development. A strategic planning thread to develop concepts for qualitative off-city settlements that counteract uncontrolled urban sprawl with monofunctional residential areas for urban poor people was deduced. The other thread asks for pathways for inner-city development with innovative, vertical, in-city projects. A final observation was that climate change and the COVID-19 pandemic are worsening the situation in informal settlements, thus strengthening the argument for the planned decentralization of Metro Manila’s congested urban areas.Item Open Access New methods for local vulnerability scenarios to heat stress to inform urban planning : case study City of Ludwigsburg/Germany(2021) Birkmann, Jörn; Sauter, Holger; Garschagen, Matthias; Fleischhauer, Mark; Puntub, Wiriya; Klose, Charlotte; Burkhardt, Albrecht; Göttsche, Franziska; Laranjeira, Kevin; Müller, Julia; Büter, BjörnAdaptation strategies to climate change need information about present and future climatic conditions. However, next to scenarios about the future climate, scenarios about future vulnerability are essential, since also changing societal conditions fundamentally determine adaptation needs. At the international and national level, first initiatives for developing vulnerability scenarios and so-called shared socioeconomic pathways (SSPs) have been undertaken. Most of these scenarios, however, do not provide sufficient information for local scenarios and local climate risk management. There is an urgent need to develop scenarios for vulnerability at the local scale in order to complement climate change scenarios. Heat stress is seen as a key challenge in cities in the context of climate change and further urban growth. Based on the research project ZURES (ZURES 2020 website), the paper presents a new method for human vulnerability scenarios to heat stress at the very local scale for growing medium-sized cities. In contrast to global models that outline future scenarios mostly with a country-level resolution, we show a new method on how to develop spatially specific scenario information for different districts within cities, starting from the planned urban development and expansion. The method provides a new opportunity to explore how different urban development strategies and housing policies influence future human exposure and vulnerability. Opportunities and constraints of the approach are revealed. Finally, we discuss how these scenarios can inform future urban development and risk management strategies and how these could complement more global or national approaches.Item Open Access Adaptation after extreme flooding events : moving or staying? The case of the Ahr Valley in Germany(2023) Truedinger, Alessa Jasmin; Jamshed, Ali; Sauter, Holger; Birkmann, JoernMore than 130 lives were lost in the 2021 heavy precipitation and flood event in the Ahr Valley, Germany, where large parts of the valley were destroyed. Afterwards, public funding of about 15 billion Euros has been made available for reconstruction. However, with people and settlements being in highly exposed zones, the core question that is not sufficiently addressed is whether affected people want to rebuild in the same place, or rather opt to move out. The paper explores this question and assesses motivations and reasons for moving or staying in the Ahr Valley. For this purpose, a household survey was conducted focusing on 516 flood-affected households. The collected data was analyzed using descriptive and inferential statistics. The results revealed that the ownership of the house or flat significantly influenced the decision of whether to stay or to leave. In addition, an attachment to the place and the belief that such extreme events occur very rarely influenced the decision to stay and rebuild. Age, gender and household income barely influenced the decision to stay or to move to a new place. Interestingly, results demonstrated that many respondents view settlement retreat and the relocation of critical infrastructures as important options to reduce risk, however, many still rebuild in the same place. These insights enable local policy and practice to better address the needs of the population in terms of whether to stay or move after such an extreme disaster.Item Open Access Heat vulnerability and adaptive capacities : findings of a household survey in Ludwigsburg, BW, Germany(2021) Laranjeira, Kevin; Göttsche, Franziska; Birkmann, Joern; Garschagen, MatthiasIn 2019, record-setting temperatures in Europe adversely affected human health and wellbeing (WMO 2020) and cities - thus, people in urban areas suffered particularly under heat stress. However, not only heat stress but also the differential vulnerability of people exposed is key when defining adaptation priorities. Up to now, local data on vulnerability and particularly adaptive capacities is rather rare. Various aspects of human vulnerability to heat and capacities to adapt to heat stress in urban areas still have to be explored and assessed, for example in terms of the adaptation at home, during work or while commuting to work. The paper presents new findings of a household survey on how and where different groups experience heat stress and how they assess their susceptibility and capacities to cope and adapt. The findings are based on a survey conducted in the medium-sized city of Ludwigsburg, Germany. Findings show significant linkages and correlations between socio-economic factors and heat vulnerability and capacities to respond. The analysis gives special emphasis to relationships between willingness to implement adaptive measures to reduce heat stress risks and risk perception and adaptive capacities. Particularly, the analysis of future adaptation options and the ability and willingness of different households to implement these provides new insights on the differential capacities to adapt and the need for tailor-made transformation programs.Item Open Access Development, mapping and validation of resilience and vulnerability indicators across spatial scales for climate related hazards(2021) Feldmeyer, Daniel; Jörn, Birkmann (Prof. Dr.-Ing.)Item Open Access Planning for climate change: an assessment of vulnerability in the city of São Paulo(2022) Batista Resende, Nayara CarolineThe evidence on climate change and its implications to the future generations have motivated an increasing discussion on adaptation agendas and the necessity to plan more resilient urban spaces. However, implementing effective approaches for climate change adaptation are particularly challenging in countries like Brazil, where the planning of an adequate infrastructure system was not able to accompany the accelerated urbanisation process. Particularly in the city of São Paulo, such rapid urban population growth contributed to an urbanisation that is territorially extensive and characterised by socio-spatial inequalities and severe environmental issues. As the existent inequalities are predicted to aggravate the effects of climate change in the livelihoods of the population, it becomes of utmost importance to identify and address current vulnerabilities in order to strengthen the resilience of cities. Therefore, the aim of the thesis is to identify areas within the municipality of São Paulo that are subjected to a greater risk when faced with extreme events and climate change, so that vulnerable regions, sectors or population groups can be prioritised when planning adaptation strategies. Thus, a vulnerability assessment was elaborated through the construction of a social vulnerability index and the geospatial analysis of data using GIS tools. The results of the assessment were then combined to data regarding the susceptibility to flood events in order to produce a map of risk posed by flooding, so that “territories of risk” - where social and environmental vulnerabilities overlap - could be identified for intervention.Item Open Access Spatial planning and systems thinking tools for climate risk reduction : a case study of the Andaman Coast, Thailand(2022) McMillan, Joanna M.; Birkmann, Joern; Tangwanichagapong, Siwaporn; Jamshed, AliThe impact of climate change and related hazards such as floods, heatwaves, and sea level rise on human lives, cities, and their hinterlands depends not only on the nature of the hazard, but also on urban development, adaptation, and other socioeconomic processes that determine vulnerability and exposure. Spatial planning can reduce climate risk not just by influencing the exposure, but also by addressing social vulnerability. This requires that relevant information is available to planners and that plans are implemented and coordinated between sectors. This article is based on a research project in Thailand, particularly on the results of multi-sectoral workshops in the case study region of the Andaman Coast in southern Thailand, and draws upon climate risk, spatial planning, and systems thinking discourses. The article formulates recommendations for planning in the context of Thailand that are relevant for other rapidly growing and urbanizing regions. Among other conclusions, it suggests that systems thinking approaches and cross-sectoral strategies are ways to grasp the interdependencies between and within climate risk and spatial development challenges.Item Open Access Infrastructure cost implications of urban forms in developing countries : an analysis of development patterns in Ghana(2012) Adaku, Ebenezer; Siedentop, Stefan (Prof. Dr.-Ing.)The interdependency or relationship between infrastructure costs and urban form has been an important issue in town and regional planning over the years. Debates have generated among practitioners and theorists for over three decades now as to which development is the most cost efficient. However, the conclusions are still fuzzy and not clear, partly, because both practitioners and theorists often deliberately or unintentionally gloss over the realistic impacts of alternative development patterns in their submissions. Interestingly, most planning authorities rarely know and consider the costs of alternative development patterns in their decision making process. Besides, studies on infrastructure costs efficiency of alternative developments have constantly focused on developed countries without any attention to developing countries. This study then sought to contribute to the debate from developing countries’ perspective – using Ghana as the reference point – by analysing the effects of urban forms on infrastructure costs from both developing and developed countries’ points of view; determining the urban form that is infrastructure costs efficient as well as recommending to planners and policy makers in developing countries, possible areas in the development process, where infrastructure costs could be reduced. In approaching the study, both qualitative and quantitative methods were employed. The qualitative approach deals with the literature review of urban sprawl, particularly its general impacts and influence on the costs of infrastructure. Again, the phenomenon of urban sprawl is situated in the context of both developing and developed countries with differences and similarities of attributes in the different economic regions of the world ascertained. The literature review, further, focuses on how infrastructure costs relate to urban forms as well as analysing how the urban structures (with respect to social and spatial distributions) in both developing and developed countries affect infrastructure costs and financing. The conclusions of the literature review form the bedrock of the investigation and further reinforce the isolation of the effect of urban configuration on infrastructure costs. A graph theoretic tool, by means of AutoCAD, was employed for further isolation of the effect of urban configuration on infrastructure costs. Pattern classification – to delineate the primary urban patterns – coupled with agreement in literature on historical and current urban patterns gave rise to four hypothetical residential neighbourhood patterns – tributary, radial, grid and hybrid patterns. The four hypothetical patterns held all other factors constant and isolated the effect of street patterns and density on the capital costs of roads, water and electricity distribution networks. The study found out that, generally, the major factors that drive the current urban development patterns – urban sprawl – in developed countries have reached, relatively, higher levels of development in comparison with developing countries. Therefore, developed countries have higher urban dispersion potential and hence higher infrastructure costs vis-à-vis developing countries. The phenomenon also occasions a shift from intra-city to inter-city infrastructure costs concerns in the case of developed countries while in developing countries, emphasis is on intra-city infrastructure costs concerns with respect to urban forms. Again, the phenomenon of urban sprawl is perceived to be occasioned by market distortions and failures. The market distortions and failures leading to urban sprawl are deemed to be anchored in the cost-sharing scheme of infrastructure financing. Hence, the externalities and market failures associated with the cost-sharing scheme (which induces urban sprawl) could be dealt with so as to ensure more efficient urban forms through marginal costs pricing of infrastructure. The phenomenon of urban sprawl albeit evident in developing counties (particularly Ghana), does not fit exactly into the developed countries’ scheme of urban sprawl – both in causes and impacts. Besides, the urban structures of both developing and developed countries are different and have different implications on the costs of infrastructure development and financing. The study also found out that there is a relationship between urban forms and infrastructure costs. However, the relationship is not a single relationship but rather a multiple one. The intrinsic purpose of these relationships, as claimed by studies in developed countries, is independent of the socio-economic situation of any particular region. Hence, this relationship is presumably applicable in developing countries as well. It has also been shown in this study that apart from density, lot size, lot shape, location and dispersion of developments, street pattern or configuration relates to and has influence on infrastructure costs, particularly network infrastructure. In isolating the effect of street patterns on urban forms, the total capital costs of three infrastructure (roads, water and electricity distribution networks) revealed the tributary pattern as the most economical pattern in terms of the capital costs of linear infrastructure while the grid pattern is the least economical. The tributary pattern showed a 27% costs savings per dwelling over the costs of the grid pattern. The radial and hybrid patterns also indicated 9% and 3% savings per dwelling, respectively, in comparison with the grid pattern. Clearly, the savings in capital costs of linear infrastructure by the tributary, radial and hybrid patterns in comparison with the grid pattern, largely, resulted from savings in water distribution and road networks. The study showed that – it appears – other factors such as demand, density and type of distribution system other than the configuration of the street pattern influence the costs of electricity distribution network significantly. The capital costs per dwelling showed a gradual rise in infrastructure cost as one moved from the pure tributary pattern towards the pure grid pattern. Besides, in isolating the effect of density on linear infrastructure costs, it was revealed that the capital costs per dwelling of linear infrastructure reduce sharply, initially, with increasing density and later reduce, marginally, with further increments in density. Again, a density from 13 DPH to 53 DPH means approximately a 300% increment in density. However, the corresponding decrease in capital costs per dwelling for linear infrastructure was about 68% across the alternative hypothetical residential patterns. The general street pattern in Ghana is the cellular or grid type which is expensive in terms of linear infrastructure. Thus, since most developing countries (including Ghana) have fiscal challenges, urban configurations which reduce infrastructure costs and enhance revenues would be more appropriate. Thus, as shown by this study, the tributary pattern appears to fulfil this goal. However, the shortfall in accessibility – a key planning goal – could be augmented by a carefully designed network of footpaths. This measure fits well into Ghana or developing countries’ scheme of transportation – slow mode or walking. Again, geometry seems to provide a tool to optimise the values of infrastructure costs minimisation and accessibility enhancement. The fused grid, a new residential neighbourhood layout, is a good example. See Grammenos et al. (2008) for more discussions on the fused grid model. Besides, the price of infrastructure comprises costs and profits. Hence, an approach like urban configuration which seeks to reduce the costs is not enough. Other factors or areas which also influence the price of infrastructure to the user should also be considered and their effects – preferably – minimised. Such areas are developer or client’s costs, risks and contingencies related to the infrastructure development and profit margin of the construction contractor or developer.Item Open Access Assessing dynamics of rural-urban linkages and their influence on rural vulnerability to extreme flood events : case study of three rural farming communities in Punjab, Pakistan(2021) Jamshed, Ali; Birkmann, Jörn (Prof. Dr.-Ing. habil.)Although rural areas and cities are intrinsically linked, the vulnerability of rural households and communities to hazards or extreme weather and climatic events is often assessed without considering their relationships to cities. These linkages are important due to interdependencies between rural and urban areas for socio-economic and physical growth. Moreover, extreme events can lead to dramatic shifts in societal processes, disrupt rural-urban linkages, and affect rural vulnerability; these matters need to be investigated. Considering these gaps in knowledge, this study aims to conceptualise and understand rural vulnerability with respect to the dynamics of rural-urban linkages in the case of flooding, with a special focus on spatial factors like city size and proximity to the city. To do so, a mixed methods approach was adopted in this research. Still, the present study is largely based on quantitative techniques. First, the current literature on rural-urban linkages, vulnerability and factors that influence them was critically reviewed, and a unified framework was proposed to connect the elements of rural-urban linkages and flood vulnerability. The framework was designed to examine changes in rural-urban linkages and the subsequent impact on rural vulnerability to flooding. For empirical research, three case studies (Darya Khan, Muzaffargarh, and Multan) were selected in the Punjab province of Pakistan. A multistage, mixed methods sampling approach was applied to derive 325 samples. Secondary data, observations and a focus group discussion deepened understanding of the topic. The household survey, using a structured questionnaire, was administered to collect information from the required sample, comprised of a flood-affected rural population surrounding three different-sized cities and at varied proximity. The data were analysed using descriptive statistics (frequency analysis, cross-tabulation) and inferential statistics (correlation, regression, chi-square, the Mann-Witney U test). Moreover, an index-based approach was developed to obtain the composite values of the three components of vulnerability: (1) exposure, (2) susceptibility and (3) capacity. The findings show that flooding severely affects rural households both directly and indirectly. The ramifications have led to several changes among rural households; most notably, they have modified how they earn a living and their relationship with the nearest major city. Floods have shifted the flow of people, information, finances, goods, and services between rural and urban areas. The research indicates that rural-urban linkages are altered in that flooding both increases and decreases rural households’ dependence on cities in different ways. These outcomes are largely driven by socio-economic, spatial, and flood-related factors. In terms of vulnerability, first, the findings signal that rural populations surrounding smaller cities are less exposed, but more vulnerable, as compared to rural households that surround larger cities. This is because rural populations adjoining larger cities are better able to deal with flood hazards due to stronger linkages. Secondly, the results confirmed that distance to the city influences the vulnerability of surrounding farming households. Rural farming households located close to cities are less vulnerable, mainly due to a better transfer of services and facilities from cities, which has made such households more educated, informed, financially strong and more closely connected, with easier access to public and private institutions. Thus, city size and proximity to the city modify linkages that further impact the flood vulnerability of the rural population. Lastly, changes in linkages made by rural households following a flood influence their overall vulnerability differently; increasing linkages with the city after a flood reduce their vulnerability, while decreasing linkages with the city exacerbate it. These changes in linkages are used to adapt to future floods and affect rural households’ vulnerability both positively and negatively. Hence, the dynamics of linkages and rural households’ exchanges with cities are crucial to reducing their vulnerability to future flood hazards. This study paves the way for regional planners and disaster managers to establish synergies between them for devising integrated flood management and development strategies that strengthen linkages, mitigate disparities and curtail vulnerability.Item Open Access Investigation of urban sprawl on the basis of remote sensing data : a case study in Jiangning, Nanjing City, China(2012) Li, Feng; Siedentop, Stefan (Prof. Dr.-Ing.)The dissertation is continuing research on the project named "Sustainable Development by Integrated Land Use Planning (SILUP) ", which has been completed cooperatively by both Chinese and German research institutions, taking Jiangning District as a typical research area to recognize the spatial patterns, monitor dynamic change, measure distinct extents, analyze the driving forces and access impacts of urban sprawl based on the technology of Remote Sensing (RS), Geographic Information System (GIS) and so on. Over the past 30 years, urban development in China has been remarkable. Land development and consumption have been out of control and kept expanding massively, especially to marginal areas of some metropolises. The undesirable growth patterns in Chinese cities appear to threaten the goal of sustainable development and impose some costs socially, economically and environmentally on households, firms and governments. At present, the research on urban sprawl in China is still in a preliminary stage- the basic characteristics of urban sprawl are not explicitly defined and the understanding of its internal mechanisms has been maintained at the level of empirical theory. The dissertation deals with the existing literatures on the subject of urban sprawl, undertaking a thorough review in terms of similarities and differences, consensuses and disagreements among many researchers and publications by comparing definitions, indicators, causes and costs between the sprawl in Western countries and China. Looking at the example of the United States, urban sprawl occurred within a perfect market economic system. However, urban sprawl in many cities of China has emerged during a transition period of China's economy from a planned economic system to a market economic system. Is it appropriate to transfer the Western conceptualization of urban sprawl to China? To what extent can these results be applicable to China? Therefore, it is urgent necessary to find ways to research urban sprawl in Chinese cities. Key questions should be answered: What is the exact definition of urban sprawl? How do we express the basic characteristics of urban sprawl explicitly? What are the internal mechanisms of urban sprawl? What are the driving forces and impacts of sprawl? The objective of this dissertation is to structure a complete framework for areas in China which have similar development backgrounds as Jiangning, provide ideas of urban sprawl study in some developing countries which also have similar a development background with Jiangning and give references and ideas for comparative study on the problem of urban sprawl between areas in Western countries and China. This dissertation intends to provide some cautions to decision-makers which they can use to implement good planning for the future development of Jiangning.