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 Linkages between typologies of existing urban development patterns and human vulnerability to heat stress in Lahore(2022) Iqbal, Nimra; Ravan, Marvin; Jamshed, Ali; Birkmann, Joern; Somarakis, Giorgos; Mitraka, Zina; Chrysoulakis, NektariosThe combined effects of global warming, urbanization, and demographic change influence climate risk for urban populations, particularly in metropolitan areas with developing economies. To inform climate change adaptation and spatial planning, it is important to study urban climatic hazards and populations at risk in relation to urban growth trends and development patterns. However, this relationship has not been adequately investigated in studies dedicated to climate vulnerability. This study identifies the typologies of development patterns within Lahore, Pakistan, investigates the heat vulnerability of residents at a neighborhood scale, and establishes a relationship between both of these factors. We identified urban clusters with diverse development patterns. Fourteen context- and site-specific indicators were selected to construct a human heat vulnerability index. Weighted sum, cluster analysis, and ANOVA test of variance were conducted to analyze the data. Our results demonstrate that development patterns significantly influence human vulnerability to heat stress, e.g., vulnerability is higher in older cities and undeveloped neighborhoods with less diverse land uses. These findings are essential for informing policy-makers, decision-makers and spatial planners about proactive adaptation planning in dynamic urban environments.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 Risk reduction through managed retreat? : investigating enabling conditions and assessing resettlement effects on community resilience in Metro Manila(2024) Lauer, Hannes; Chaves, Carmeli Marie C.; Lorenzo, Evelyn; Islam, Sonia; Birkmann, JörnManaged retreat, a key strategy in climate change adaptation for areas with high hazard exposure, raises concerns due to its disruptive nature, vulnerability issues and overall risk in the new location. On-site upgrading or near-site resettlement is seen as more appropriate and effective compared to a relocation far from the former place of living. However, these conclusions often refer to only a very limited set of empirical case studies or do not sufficiently consider different context conditions and phases in resettlement. Against this background, this paper examines the conditions and factors contributing to community resilience of different resettlement projects in Metro Manila. In this urban agglomeration reside an estimated 500 000 informal households, with more than 100 000 occupying high-risk areas. In light of the already realized and anticipated climate change effects, this precarious living situation exposes families, already socio-economically vulnerable, to an increased risk of flooding. The response of the Philippine government to the vexing problem of informal dwellers has been large-scale resettlement from coasts, rivers and creeks to state-owned sites at urban fringes. However, only very few resettlement projects could be realized as in-city projects close to the original living space. The study employs a sequential mixed-method approach, integrating a large-scale quantitative household survey and focus group discussions (FGDs) for a robust comparison of resettlement types. Further, it reveals community-defined enabling factors for managed retreat as climate change adaptation strategy. Results indicate minor variations in well-being conditions between in-city and off-city resettlement, challenging the expected impact of a more urban setting on resilience. Instead, essential prerequisites for resettlement involve reduced hazard exposure, secure tenure and safety from crime. Beyond these essential conditions, social cohesion and institutional support systems emerge as significant influencers for the successful establishment of well-functioning new settlements. With this findings, the study contributes to the expanding body of literature on managed retreat, offering a comprehensive evaluation based on extensive datasets and providing entry points for the improvement of retreat as a climate change adaptation strategy.Item Open Access Global vulnerability hotspots : differences and agreement between international indicator-based assessments(2021) Feldmeyer, Daniel; Birkmann, Joern; McMillan, Joanna M.; Stringer, Lindsay; Leal Filho, Walter; Djalante, Riyanti; Pinho, Patricia F.; Liwenga, EmmaClimate change impacts and their consequences are determined not only by the intensity and frequency of different climatic hazards but also by the vulnerability of the system, society or community exposed. While general agreement exists about the importance of assessing vulnerability to understand climate risks, there is still a tendency to neglect global and regional vulnerability patterns because they are hard to quantify, despite their value in informing adaptation, disaster risk and development policies. Several approaches to quantifying global vulnerability exist. These differ in terms of the indicators they use and how they classify countries or regions into vulnerability classes. The paper presents the structure of selected approaches and explores two indices in depth. The aim of this paper is to assess the level of agreement between selected international indicator-based assessments of vulnerability, at the level of climate regions. Results suggest that the two major global vulnerability assessments analysed largely agree on the location of the most and least vulnerable regions when these assessments are aggregated to a regional scale using the IPCC’s climate regions. The paper then discusses the robustness of the information derived and its usefulness for adaptation, disaster risk and development policies. Measuring progress towards reducing vulnerability to climate change and hazards is key for various agencies and actors in order to be able to develop informed policies and strategies for managing climate risks and to promote enabling conditions for achieving the SDGs and building resilience.Item Open Access Probabilistic tsunami hazard assessment in meso and macro tidal areas : application to the Cádiz Bay, Spain(2021) González, Mauricio; Álvarez-Gómez, José A.; Aniel-Quiroga, Íñigo; Otero, Luis; Olabarrieta, Maitane; Omira, Rachid; Luceño, Alberto; Jelinek, Robert; Krausmann, Elisabeth; Birkman, Joern; Baptista, Maria A.; Miranda, Miguel; Aguirre-Ayerbe, IgnacioTsunami hazard can be analyzed from both deterministic and probabilistic points of view. The deterministic approach is based on a “credible” worst case tsunami, which is often selected from historical events in the region of study. Within the probabilistic approach (PTHA, Probabilistic Tsunami Hazard Analysis), statistical analysis can be carried out in particular regions where historical records of tsunami heights and runup are available. In areas where these historical records are scarce, synthetic series of events are usually generated using Monte Carlo approaches. Commonly, the sea level variation and the currents forced by the tidal motion are either disregarded or considered and treated as aleatory uncertainties in the numerical models. However, in zones with a macro and meso tidal regime, the effect of the tides on the probability distribution of tsunami hazard can be highly important. In this work, we present a PTHA methodology based on the generation of synthetic seismic catalogs and the incorporation of the sea level variation into a Monte Carlo simulation. We applied this methodology to the Bay of Cádiz area in Spain, a zone that was greatly damaged by the 1755 earthquake and tsunami. We build a database of tsunami numerical simulations for different variables: faults, earthquake magnitudes, epicenter locations and sea levels. From this database we generate a set of scenarios from the synthetic seismic catalogs and tidal conditions based on the probabilistic distribution of the involved variables. These scenarios cover the entire range of possible tsunami events in the synthetic catalog (earthquakes and sea levels). Each tsunami scenario is propagated using the tsunami numerical model C3, from the source region to the target coast (Cádiz Bay). Finally, we map the maximum values for a given probability of the selected variables (tsunami intensity measures) producing a set of thematic hazard maps. 1000 different time series of combined tsunamigenic earthquakes and tidal levels were synthetically generated using the Monte Carlo technique. Each time series had a 10000-year duration. The tsunami characteristics were statistically analyzed to derive different thematic maps for the return periods of 500, 1000, 5000, and 10000 years, including the maximum wave elevation, the maximum current speed, the maximum Froude number, and the maximum total forces.Item Open Access A conceptual framework to understand the dynamics of rural-urban linkages for rural flood vulnerability(2020) Jamshed, Ali; Birkmann, Joern; Feldmeyer, Daniel; Rana, Irfan AhmadRural areas are highly vulnerable to floods due to limited social, economic, and physical resources. Understanding rural vulnerability is vital for developing effective disaster risk reduction strategies. Even though rural areas and cities are intrinsically linked, rural vulnerability was assessed without considering its relation to cities. Numerous theoretical frameworks on systemizing and assessing vulnerability were developed with varying level of scope and depth in terms of scale, dimensions, and components. Nevertheless, these frameworks did not explicitly mention the impact of flood or other hazards on the linkages between spatial units i.e., rural and urban. This study aims to understand and conceptualize the rural vulnerability with respect to the dynamics of rural-urban linkages in the case of flood events. To do so, current literature on rural-urban linkages, vulnerability, as well as factors that influence them were critically reviewed. Taking into account the main elements of rural-urban linkages (flow of people, information, finances, goods and services), components of vulnerability (exposure, susceptibility, and capacity), and factors (social, economic, institutional, infrastructural, spatial, and environmental), a unified framework is proposed. The framework underscores that the role of rural-urban linkages is essential to fully understand rural flood vulnerability. Moreover, the framework highlights the role of spatial factors-city size and proximity to the city-as crucial to comprehend rural vulnerability. This framework can be used as a tool for understanding multifaceted rural vulnerability for climate change adaptation and disaster risk reduction considering spatial development perspective. In this context, empirical investigations can be made to validate the proposed framework and policies can be introduced accordingly. Overall, the proposed framework can help recognize concepts and links of vulnerability, rural–urban dependencies, and rural development dynamics.