The last 2023 IPCC report draws attention to the change in the occurrence and frequency of weather extremes and natural hazards (Lee et al., 2023). It emphasizes the urgent need for climate change mitigation and adaptation to counteract the risks to life, nature, values, and societies. A recent study by Köhler et al. (2023) provides insight into the fact that frequent flood experiences increase the willingness to undertake protective actions at the individual level but simultaneously lead to decreased self-reported resilience. Still, there is a gap in understanding why frequent flood experiences influence protective motivation and what other factors play a role. Building upon this, this study explores the role of frequent experience in protective motivation and why more experienced people are more likely to adapt. Also, we introduce a measure for control experience, the individual's perceived efficacy in managing past flood situations, to understand the role of perceived resistance in affecting protective motivation.

To meet this aim, we apply Protection Motivation Theory (PMT) from the field of psychology to understand how frequent flood events and control experiences influence coping and threat appraisal, two factors that have been shown to impact people's motivation to change behavior. Structural equation Modeling is used to detect processes and interactions between several variables in one model. The data comes from a survey in Saxony (Germany) in 2020.

We find that both the frequency of experienced floods and the control experience increase threat appraisal but decrease coping appraisal. Threat appraisal could, therefore, be a channel through which flood experience positively influences protective motivation. The negative influences of flood experience on coping appraisal could limit this positive impact, at least to some extent. Our findings carry profound implications in understanding better the protective behavior of people who have undergone multiple flood events. We deliver crucial insights into how the frequency of experienced floods, perceived efficacy in managing past flood events, and individual protective behavior are related.

Citations:

Lee, H., Calvin, K., Dasgupta, D., Krinner, G., Mukherji, A., Thorne, P., ... & Park, Y. (2023). IPCC, 2023: Climate Change 2023: Synthesis Report, Summary for Policymakers. Contribution of Working Groups I, II and    III to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Core Writing  Team, H. Lee and J. Romero (eds.)]. IPCC, Geneva, Switzerland.

Köhler, L., Masson, T., Köhler, S., & Kuhlicke, C. (2023). Better prepared but less resilient : the paradoxical impact of frequent flood experience on adaptive behavior and resilience. Natural Hazards and Earth System Sciences, 23(8), 2787–2806.

How to cite: Köhler, L. and Han, S.: The leverage effect of experience: how flood frequency and perceived loss of control influence individual protective motivation, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-18999, https://doi.org/10.5194/egusphere-egu24-18999, 2024.

Metro Manila is the Philippines’ largest metropolitan region. It is highly urbanized, densely populated, and situated on the coast where it is highly exposed to natural disasters and rising sea levels. Therefore, a significant question for Metro Manila concerns how to adapt to such current and future climate hazards. To address this urgent need to adapt to climate change while simultaneously tackling pronounced urban and sustainable development challenges, a multitude of policy and planning documents have been formulated within the Philippines across varying scales. These documents represent a suitable means of analyzing the legal-institutional dimension of adaptation governance in Metro Manila. One pressing question in the field of adaptation governance, which remains understudied, is who is actually responsible for adaptation. Hence, this research aims to answer how, in the documents, roles and responsibilities for adaptation are divided amongst the different actors who are parties to the ‘social contract’ on adaptation. The research questions are as follows: 1) What is the discourse on roles and responsibilities in the policy and planning documents? 2) Which actors are described as being responsible for implementing adaptation strategies, and who should benefit from these actions? 3) Are these actors’ roles and responsibilities clearly defined in the documents, and which types of responsibilities are defined? A qualitative methodology was utilized to answer these questions. First, existing literature was reviewed to synthesize a framework for assessing different types of roles and responsibilities (such as financial, legal, and moral) as well as evaluation criteria (such as accountability, responsiveness, and transparency). Then, the framework was applied to 39 policy and planning documents from the national to the local level by means of a qualitative content analysis in MAXQDA. The findings show that responsibilities are more commonly referred to than roles, and that clearly defined responsibilities throughout the adaptation policy cycle are increasingly considered to be an important aspect for effective implementation. The documents vary in the extent to which they clearly define responsibilities for different actors, but the roles and responsibilities of governmental actors are defined most clearly. However, the adaptation stakeholder landscape is quite complex and stretches beyond governmental actors to incorporate academia, citizens, civil society and non-governmental organizations, international organizations and foreign actors, future generations, and the private sector. The latter is often called upon to aid the government in fulfilling financial responsibilities and infrastructure construction. Lastly, the analysis shows that cooperative and participatory processes, as mechanisms for influencing social contracts for adaptation, are playing progressively important roles. Future research will thus conduct interviews to explore how, in collaborative efforts and participatory processes, questions around social acceptability and political responsibilities are discussed and where the disparities lie between the legal-institutional responsibilities captured in the documents, and practiced and expected responsibilities. This is key for making some of the implicit developments more explicit in the timely discussion about who is responsible for doing what in adaptation, and which actors benefit or lose out.

How to cite: Grobusch, L. C., Liss, B. M., and Garschagen, M.: Who is responsible for addressing climate risks in coastal cities? Insights from a policy document analysis of Metro Manila, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-14544, https://doi.org/10.5194/egusphere-egu24-14544, 2024.

In disaster science, the discussions predominantly stem from the various notions of risk and associated concepts. While understanding risk is an undeniable necessity to comprehend disasters, it is inadequate. This is because, risk only provides an understanding of what is, but it doesn’t describe what could be done and what should be done. As such, there are additional parameters that needs to be included to fully capture the complexities of disaster risk reduction. To this end, it is argued that disasters need to be framed through additional lens of law and ethics that interact with the concepts of risk. A framework, termed Ethics for 4Rs (E4Rs) where 4Rs represent the 4 phases of disaster cycle (reduction, readiness, response, and recovery), is proposed where the three main concepts: risk, ethics, and law interact continuously. Additionally, this framework emphasizes the need to explicitly express the importance of our values, i.e., ethics as disasters are fraught with difficult decisions. This theoretical framework was derived based on understanding gained through studies on the use of post-earthquake cordons as a response and recovery strategy following major disasters in three countries: Aotearoa New Zealand (Christchurch earthquake 2011), Italy (L’Aquila earthquake 2009), and Nepal (Gorkha earthquake 2015). For the case studies, a qualitative research methodology was used for data collection, where 44 experts from varying backgrounds such as politicians, emergency managers, city council members, police, community leaders among others were interviewed. The development of this framework has also been supported through review of ethical concepts from health sciences, in particular public health sciences. This is because discussions on ethics in relation to disasters are limited in literature where as they have been developed more thoroughly in public health sciences. Although, there are differences in disasters due to natural hazards and public health events such as a pandemic, the complexity, urgency, scale and the need to make difficult decisions remain the same and are comparable. Finally, it is suggested that this framework will bring about discussion on disasters and ethics where a significant gap remains in the current disaster science discourse.

How to cite: Shrestha, S. R.: Risk, Ethics, and Law: A framework (E4Rs) to understand disasters, learned through response to earthquake disasters in Aotearoa New Zealand, Italy, and Nepal. , EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-10224, https://doi.org/10.5194/egusphere-egu24-10224, 2024.

Promoting public access to Urban Green Spaces is a central objective in sustainable city planning. Urban Green Spaces can play a vital role in enhancing various aspects of public life, including human recreation, local climate regulation and rainwater infiltration. However, in most metropolitan areas, especially in developing countries and emerging economies, Urban Green Spaces face competition with strong economic interests leading to their deterioration over the last decades. Our study critically examines this assumption for two Vietnamese delta cities, namely Hanoi and Ho Chi Minh City. In particular, we use multi-spectral satellite imagery from the Sentinel-2 mission to create seasonal maps of the Normalized Difference Vegetation Index in order to estimate the local proportion of densely vegetated areas. By blending these maps with population data from the National Census of 2019, we determine the spatial distribution of Urban Green Spaces per capita in both cities and interpret these findings against the background of recent spatial planning efforts. Spanning seven dry seasons in total (Dec 2016 – Jan 2023), the satellite data furthermore allow us to compare the temporal development of Urban Green Spaces and tentatively extrapolate these trends into the near future. Our preliminary results suggest that districts with particularly high percentages of Urban Green Spaces in Hanoi generally encompass the historic city core, while the greenest districts of HCMC are located in the newly established city-within-city Thu Duc east of the Saigon River. Moreover, the Urban Green Space per capita in Hanoi is nearly twice as high as in Ho Chi Minh City amounting to 11.6 and 6.8 square meters, respectively. Judging from the NDVI time series, these figures seem relatively stable with variations in the order of 1 square kilometre per year. Yet, ongoing urbanization trends will put stress on both the proportion of Urban Green Spaces and the number of inhabitants benefitting. Even though the stability of the Normalized Difference Vegetation Index is subjected to atmospheric and climatic boundary conditions, we can report that measurement-inherent variations in our study only accounted for standard deviations below 0.1 at selected locations with constant land cover. Consequently, the applied methodology is considered a valid instrument for documenting spatial distributions and temporal developments in order to support and advocate the advantages of Urban Green Spaces in future spatial planning.

How to cite: Scheiber, L., Zühlsdorff, V., Son, N. T., Duong, N. H., Quan, N. H., Garschagen, M., and Reimuth, A.: Comparing the distribution and development of Urban Green Spaces in the two Vietnamese delta cities Hanoi and Ho Chi Minh City, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-4099, https://doi.org/10.5194/egusphere-egu24-4099, 2024.

There is rising discussion focused on the ways in which urban growth and expansion, often into flood-prone areas, takes effect on the exposure and vulnerability profiles of the respective households. In order to drive city-wide and regional analysis, remotely sensed urban structure types are increasingly being used as a proxy for socio-economic characteristics. However, whether and how urban structure types in fact match the nuanced realities of socio-economic exposure and vulnerability to floods remains largely unclear. Resolving this question is of particular relevance for improving flood risk assessments in rapidly growing coastal cities with a high hazard exposure. We therefore use Ho Chi Minh City in Vietnam as a case study to develop a detailed composite indicator index for measuring the exposure and vulnerability at household level in flood-affected parts of the city, based on household survey data. We then correlate this index to urban structure types to see whether morphology characteristics map against socio-economic vulnerability and exposure profiles. In order to allow for an assessment of temporal trends, data from a repeated survey (two years after the first) is used to examine dynamics in exposure, vulnerability and urban development.

Our research yields a number of key results (Tu et al., forthcoming): First, household vulnerability is not necessarily correlated to flood exposure. Second, the vulnerability and flood exposure levels of households are differ along an urban, peri-urban and rural gradient. Third, the exposure and vulnerability profiles only partly correlate with the urban structure types, but a certain mapping can be done with a reasonable uncertainty bandwidth in order to drive future modeling forward. These findings not only shed light onto spatial vulnerability patterns in HCMC but also on methodological advances in the field of city-wide risk and adaptation modeling. These lessons and their transferability to other coastal cities with similar adaptation pressures but different morphology and vulnerability profiling will be discussed.

How to cite: Tu, J., Reimuth, A., and Garschagen, M.: Exploring the relationship between urban morphology types and household-level flood vulnerability profiles in Ho Chi Minh City, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-16498, https://doi.org/10.5194/egusphere-egu24-16498, 2024.

Despite traditional measures to prevent disasters, climate change and urbanization increase flood risk. Thus, flood resilience has attracted increased global concern. Understanding the commonalities and differences between flood resilience and risk is arguably important for flood risk reduction. However, these factors have been seldom reported in previous studies, and discussions on the role of flood resilience in flood risk analysis, assessment, and management are lacking. In this study, the association between flood resilience and risk is discussed using a case study in the Pearl River Delta. Flood resilience is quantified using a pressure-state-response (PSR) model, while flood risk is assessed based on the hazard-vulnerability framework and the extension catastrophe progression method. The implications of considering flood resilience in flood risk analysis, assessment, and management are proposed. The results suggest that the overall flood resilience (risk) in the study area is greater (lower) than that in the highly urbanized areas, and areas with low (high) flood resilience (risk) are mainly concentrated within the highly urbanized areas. Indices extracted from human society and highly related to human activities have the same attributes in both frameworks, while indices associated with climate and geography contribute to the two con- cepts differently. Flood resilience supplements the concept of flood risk, and can be incorporated into risk assessment as an index. Moreover, pre-disruption (post-disaster) measures should follow flood risk (resilience) assessment, and strategies that foster flood resilience should be included in flood risk management. This study provides references for flood resilience improvement and risk mitigation.

How to cite: Zheng, J. and Huang, G.: Towards flood risk reduction: Commonalities and differences between urban flood resilience and risk based on a case study in the Pearl River Delta, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-2259, https://doi.org/10.5194/egusphere-egu24-2259, 2024.

Rising sea levels and changes in the frequency and intensity of storms can have physical, operational and business implications for coastal airports worldwide. Employing appropriate risk reduction measures is essential, and airports demonstrating higher adaptive capacity are generally expected to be better equipped to respond and recover quickly after a disruptive event. While a growing body of research investigates the impact of rising sea levels on coastal infrastructure systems, limited studies discuss how coastal airports can measure their adaptive performance considering the main climate extremes occurring in the coastal zone. This study presents an approach to measure coastal airports' adaptability to hazards such as rising sea levels, extreme precipitation, and storminess. The developed framework uses indicators identified in adaptation and risk assessment literature to reflect prevention, response and institutional actions to reduce climate risk. By examining the key challenges coastal airports face and best-applied practices to respond, this contribution provides insights into the drivers for action, the efficiency of existing practices to address climate challenges and qualities that coastal airports need to demonstrate to strengthen their capacity and shift towards a more informed risk management culture. 

How to cite: Voskaki, A., Budd, T., and Mason, K.: Adapting coastal airports to climate change challenges, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-6568, https://doi.org/10.5194/egusphere-egu24-6568, 2024.

Linking socio-economic and spatial structural data is a key research gap in the assessment of urban climate risk. Urban populations are increasingly exposed to adverse effects of climate change, particularly in coastal urban areas in the Global South, where information is scarce. Researchers often rely on survey results, which deliver highly detailed micro-level point data but those are costly and lack spatial coverage. Conversely, Earth observation
(EO) data offers greater spatial coverage but provides limited insights into socio-economic factors. Hence, there is a gap in integrating urban morphology data derived from EO and micro-scale survey data. We aim to address this gap by linking socio-economic and morphological data using a novel machine learning-based approach and testing whether and to what extent urban structure types (UST) can function as spatial predictors for
socio-economic profiles.
To do so, we implement a two-stage process based on k-means and random forest (RF) algorithms in two case studies. First, we employ a k-means clustering algorithm to delineate socio-economic profiles based on household survey variables relating to education, household size and composition, and asset ownership. We then used an RF classification algorithm that used USTs as predictors to extend the survey socio-economic profiles into
morphologically similar areas in two case study cities: Mumbai (India) and Ho Chi Minh City (Vietnam). In Mumbai, current socio-economic data is severely outdated (i.e., the last census was in 2011), while in Ho Chi Minh City it is only available in coarse spatial units (i.e., at the commune level). These conditions hinder research on assessing flooding vulnerability, as population growth and the mismatch between administrative units and flood hotspots introduce severe bias and uncertainty in the available data. To overcome this situation, we implemented household surveys (n=1240 and 751, respectively) in flood hotspots that cover a variety of urban structure types (e.g., compact low-rise, open mid-rise, or lightweight low-rise).
In our study, morphological information functions as a proxy for socio-economic profiles, thus providing a cost-effective and spatially explicit novel approach to assessing social vulnerability in data-scarce conditions. By starting from the household-level survey data, we avoid the most critical problems from reductionist approaches (e.g., social determinism) and recognize the limitations of data triangulation. To this end, we measure the uncertainty of the association in each step and validate the assumptions and results with local stakeholders. Our novel approach aims to use the available EO data to improve the identification of high-vulnerability areas. Albeit experimental, the spatially explicit identification provided in
this study provides crucial insights for targeted climate adaptation policy and research. By studying two rapidly evolving coastal cities, we provide a comprehensive and reproducible method to assess the challenges urban populations face under climate change.

How to cite: Mirbach, C., Pereira Santos, A., Garschagen, M., Hochschild, V., and Warth, G.: Extracting socioeconomic information with the help of urban structure types indata-scarce environments, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-21664, https://doi.org/10.5194/egusphere-egu24-21664, 2024.

Populations in many coastal urban areas are increasingly exposed to climate-related hazards, such as rising sea levels, increasing intensities and frequencies of tropical cyclones, and extreme weather events. At the same time, the number of people in coastal cities is growing and, especially in the Global South, these cities are characterised by rapid and often unplanned urbanisation and a high degree of social inequality. Hence, coastal cities are also hotspots of social vulnerability. That coastal cities are climate risk hotspots has been widely acknowledged, and adaptation is happening, especially in terms of planning and reactive responses. However, the current adaptation progress lacks implementation, evidence of effective risk reduction, and long-term pathway perspectives. A global future-oriented approach for a better understanding of the socioeconomic developments shaping challenges to adaptation is the Shared-Socioeconomic Pathway (SSP) framework. Our research uses the case study of Mumbai, one of the world’s most vulnerable cities, to apply a participatory scenario approach, downscaling the SSP narratives to the local level with bottom-up input from diverse local stakeholder groups. Our specific research question is: How do future socioeconomic urban developments affect Mumbai’s social vulnerability and challenges for adaptation? Our results provide three distinct scenario narratives for Mumbai’s socioeconomic development until 2050, including “Wider sustainability transitions”, “Partial exploitation of existing potential and current trends”, and “Increasing barriers through inequality and fragmentation”. The scenario narratives stress the relevance of addressing social inequality in urban change and development processes across different sectors, including labour, housing, transport, and health. A further prominent cross-cutting aspect resulting from the co-development of the scenario narratives with local stakeholders deals with streamlining urban planning across different governance scales (i.e., local and regional) and sectors (e.g., transportation and spatial planning). The SSP downscaling approach also sheds light on several conceptual and methodological challenges. For example, data availability guiding the drafting of plausible scenario assumptions varies significantly across different elements of the scenario narratives. Moreover, the framework is limited in considering local development pathways switching from one scenario track to another and the effects of unforeseen transformations or shocks. In conclusion, our study proves the value of developing globally nested regional scenarios to understand challenges for adaptation, consistent with research on global socioeconomic developments, and the importance of a transdisciplinary approach to guarantee plausibility, consistency and relevance for local contexts. The results of our study are relevant for a holistic understanding of future climate risk and challenges and opportunities for adaptation planning at the local scale. 

How to cite: Petzold, J., Garschagen, M., Dhiman, R., Doshi, D., Pereira Santos, A., and Parthasarathy, D.: Identifying future challenges for adaptation to climate change through insights from participatory scenario-downscaling in Mumbai, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-8172, https://doi.org/10.5194/egusphere-egu24-8172, 2024.

The recent increase in the frequency of extreme events worldwide highlights the urgent need for comprehensive and coordinated efforts to achieve sustainable recovery and resilience. However, the recovery process following such events has often been prolonged and uneven, and it is frequently overlooked in global disaster management policies. This study aims to address this gap by providing a comprehensive assessment of disaster recovery pathways after extreme flood events, by developing a multidimensional framework.

The research questions guiding this study are: What are the key elements of disaster recovery? What factors act as barriers or facilitators to recovery pathways after disasters? How do these factors contribute to building back better? To answer these questions, the study combines conceptual and empirical insights, including a literature review and an assessment of recovery pathways from recent extreme flood events in Germany and Nigeria.

A multi-methods approach was utilized, encompassing in-depth interviews with representatives from government, NGOs, the private sector, community members, and disaster recovery experts. A total of thirty-eight in-depth interviews were conducted with stakeholders from both countries. Additionally, grey literature and policy documents were analyzed. Qualitative content analysis was employed to analyze the data derived from the in-depth interviews and policy documents.

The findings highlight the significant role of relief organizations in driving recovery efforts, with a particular focus on humanitarian aspects. Moreover, sustainable changes have been observed, such as the implementation of communal heating systems and the use of sustainable materials in building reconstruction. Religious organizations have played a crucial role in providing social and psychological support during the recovery process.

Despite these positive developments, the study underscores a lack of concerted efforts to truly "build back better" during the recovery process, primarily due to political, financial, and institutional constraints. This observation holds across different cases, including the Ahr and Erftstadt in Germany and Lagos in Nigeria. These themes have been explored within the broader scope of the Sendai Framework for Disaster Risk Reduction 2015 - 2030.

How to cite: Okunola, O. and Werners, S.: A Multi-dimensional Framework for Assessing Disaster Recovery Pathways: Lessons and Experiences from Germany and Nigeria , EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-1179, https://doi.org/10.5194/egusphere-egu24-1179, 2024.

As recent IPCC reports have highlighted, urban areas are now home to most of the world’s population. The majority of such urban growth continues to occur in less developed regions and is expected to persist, specifically in Asia. Due to extensive anthropogenic change along coastal zones, as well as their inherent exposure to natural hazards such as sea level rise, erosion, and tropical storms, coastal cities are especially at risk to the adverse impacts of climate change. Having consistently ranked as one of the countries most at risk to the negative impacts of anthropogenic climate change, the Philippines has undertaken significant efforts to integrate climate change adaptation into various policies and planning documents. This research reflects on the specific practice of mainstreaming climate change adaptation (CCA), as well as disaster risk reduction (DRR) measures, into local land use planning in Metro Manila as a means of reducing the region's present and future risk. Effective land use planning represents a proactive and economical approach to managing both current and future climate change related risks, especially when taking into consideration the significant expenses necessary to remedy issues caused by poorly or unplanned development, which often most negatively impacts a community’s most vulnerable members. Specifically, the aim of this research is to take stock of what progress has been made toward mainstreaming climate change adaptation and disaster risk reduction strategies into local land use planning in Metro Manila and to understand how this impacts those who are most vulnerable to climate change. The analysis also strives to comprehend how the knowledge gained from the Metro Manila case study can be transferred to other cities in Southeast Asia facing similar challenges. Methodologically, the software MAXQDA was utilized to conduct a qualitative data analysis of 39 policy and planning documents, ranging from the national to the local level. This analysis demonstrates that policy and planning documents at all levels integrate future-oriented climate change adaptation and disaster risk reduction strategies to a certain extent. However, despite the consistent and comprehensive integration of such strategies into documents across scales, numerous documents cite significant challenges in implementing CCA and DRR strategies, especially at the local level. Poor and/or inconsistent coordination between government offices, in addition to other stakeholders, limited or poorly prioritized and difficult-to-access financing, as well as a lack of continuity in personnel due to political election cycles, particularly at the local level, were frequently referenced as representing significant barriers to proper implementation of CCA and DRR strategies. Future research will be conducted in the form of expert interviews, which will help to better understand the current issues regarding the local implementation of these strategies and in what ways these can be improved or altogether remedied.

How to cite: Liss, B. M., Grobusch, L. C., and Garschagen, M.: Mainstreaming climate change adaptation into local land use planning in Metro Manila: lessons learned and potential for knowledge transfer, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-14632, https://doi.org/10.5194/egusphere-egu24-14632, 2024.

Decisions on coastal cities flood adaptation are complicated by deep uncertainty about sea level rise, subsidence and socioeconomic trends, increasing the chance of under- or over-investment. Frameworks have been proposed to plan coastal adaptation in urban settings. In this study, we expand those frameworks to include elements critical to rational decision-making in coastal cities under deep uncertainty. Our framework, trained on the city of Shanghai, includes compound flood modeling, flood risk analysis, design and quantitative simulation of adaptation strategies, cost-benefit analysis, trade-off analysis and formulation of dynamic adaptive policy pathways (DAPP). We include land subsidence in modeling flood scenarios; we compute a diverse set of flood impacts on multiple sectors; we evaluate several techniques of cost-benefit analysis; and we include multiple adaptive strategies against compound flooding (i.e., pluvial, fluvial, coastal). We show that the hard adaptation strategies (e.g., storm-surge barriers and storage tank) can successfully reduce future increase in risk generated by sea level rise, land subsidence and socioeconomic development, by 58%~94%. In contrast, soft adaptation only generate considerable benefits when integrated with hard adaptation into hybrid strategies. A hybrid strategy that combines storm-surge barrier and wetland creation most effectively reduces flood damages and casualties, and yields promising co-benefits. We formulate DAPP for robust and flexible decision-making over time for the coming decades, which open up the decision-making space and help overcome policy paralysis due to deep uncertainty.

How to cite: Shan, X., Aerts, J. C. J. H., Wang, J., Wen, J., Yin, J., Yang, Y., Qiu, F., and Scussolini, P.: Dynamic Adaptive Policy Pathways for Flood Adaptation in Shanghai under Deep Uncertainty, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-13097, https://doi.org/10.5194/egusphere-egu24-13097, 2024.

Spatial development, particularly the rapid expansion of urban areas, is increasing disaster risk in city-regions around the world. The planning region of Stuttgart is a growing polycentric region with a high demand for housing and commercial space, and at the same time faced with increasing risk of pluvial flooding and heatwaves. Spatial planning that controls and coordinates urban development is an important tool for ex-ante disaster risk reduction. However, planners face a complex task to weigh up a myriad of development goals of which risk reduction is just one. Decision-making tools for planning practitioners and the public that quantify resilience factors spatially can support the integration of resilience and risk considerations into planning processes. In our research, we investigate the use of land-use scenarios as a way to measure the relevance of land to the hazards of pluvial flooding and the urban heat island effect and thus to risk reduction. We do so with a particular focus on operationalizing such a quantitative assessment for the regional planning level, whose task it is to coordinate the spatial development of the municipalities. Such coordination is particularly important in the context of disaster resilience in urban regions such as Stuttgart, because, for example, the development of land in one municipality can increase water runoff or decrease cooling airflows in a neighboring municipality.

In our contribution to this session, we share our insights from a combined effort by research, modelling and planning practitioners to operationalize land-use scenarios as a way to quantify the effect of urban development on risk. A central aim of our approach was relevance to regional and local planning processes. The land that we considered as potential for urban development was thus based on the current planning law. We constructed two land-use scenarios, in which all land in the region with potential for development was fictitiously used for building housing but in two different ways – one with a building density and height and level of soil sealing typical to the local setting, and the second with a more compact urban form with more green and less impervious surfaces. The aim was, firstly, to measure the effect of urban expansion on hazard exposure and, secondly, to determine if through a compact and climate-sensitive urban form the needs for more housing could be met without increasing hazard exposure. The pluvial flood hazard model and an urban climate model of the two scenarios provided useful results for the first aim, but less so for the second. In our contribution, we will share the methodological challenges of translating the scenarios for two different types of models, and discuss the results and their potential as a tool for use in spatial planning processes.

How to cite: McMillan, J. M., Göttsche, F., Janssen, H., Hoppe, H., and Birkmann, J.: Land-use scenarios for assessing climate risk as a tool for spatial planning: a case study of the Stuttgart Region, Germany, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-15338, https://doi.org/10.5194/egusphere-egu24-15338, 2024.