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Since almost half of the world’s population lives in cities and another third in settlements with similar characteristics, the current and future impacts of climate change in cities is of greatest importance. The characteristics of urban environments (reduced long-wave emissions towards the sky due to the blockage effect of the surrounding buildings, construction materials, anthropogenic heat production, lack of green and blue infrastructure) further increase ambient temperatures and cause urban heat islands. Nature-based solutions (NbS) have widely been investigated as a remedy to this challenge, which is quickly worsening due to the combined effects of climate change and the rapid densification of urban settlements. NbS cover a wide scope of measures such as planting roadside trees, greening facades or roofs, re-naturalizing rivers or unsealing of parking spaces to allow rainwater to penetrate and enable evapotranspiration. Yet, the widespread implementation of NbS often meets political, social, legal, financial or spatial barriers. In the presented study we combine interdisciplinary expertise from natural to social and economic sciences and a wide range of methods to evaluate and illustrate, exemplarily for the city of Vienna, how urban areas can implement NbS and overcome the aforementioned barriers. Therefore, (1) a list of possible NbS is compiled; (2), their performance is quantified through numerical micro-climate simulations, (3) their impact and potential trade-offs applying a socio-spatial analysis and survey, (4) individual preferences and willingness to pay are analyzed for a representative sample of 2,181 Viennese residents using a choice experiment, and finally, (5) a consolidated list of NbS is validated within policy workshops.Using this approach we find that substantially transforming an existing quarter by implementing green and blue infrastructure, as well as technical solutions (e.g. sun blinds) may reduce the ambient air temperature by up to 2°C and the mean radiant temperature on some surfaces by up to 45°C, with natural measures being more effective than technical ones. Implementing these measures within the whole city of Vienna may yield a similar temperature effect. The socio-spatial vulnerability assessment identifies few areas where a strong overrepresentation of vulnerable age groups, low-income residents and housing vulnerabilities coincide. In the city of Vienna, green gentrification owing to rising housing prices for already vulnerable groups thus seems to be very limited, especially as long-standing social housing policies and a rather strict regulation of the private housing markets lead to comparatively stable rent levels. The choice experiment shows a substantial willingness to pay for NbS, suggesting that Viennese citizens would financially support the implementation and maintenance of extensive greening measures. However, the politicians fear the conflicts with the citizens and other political parties as well as stakeholders. Stakeholders from the city authorities map potential physical and legal barriers for local implementation, such as building codes, administrative procedures for permits and inspections, or conflicts over scarce public space.

Path dependency occurs when a contingent event predetermines what further steps can be taken and self-reinforcing mechanisms lock-in any further development on a sub-optimal trajectory. Path dependency is a prominent concept in the adaptation pathways literature, but insufficiently defined and operationalised. The present paper empirically tracks all constitutive elements of path dependency for four decades of flood risk management (FRM) in two alpine mountain regions in Austria, the Ennstal and Aist river catchments, using a mixed-methods approach. FRM governance has a critical role whether decisions lead to path dependency. Lock-in manifests not just in technical structures, but also in inertia of incumbent actor coalitions and management paradigms. Sub-optimality is hard to assess for lack of clearly defined protection targets; however, it appears in the ways that structural measures are implemented—too little, too late or with negative impacts on nature conservation. Past floods do not qualify as contingent events, as they have not fundamentally changed FRM practice. By contrast, technological and institutional shifts over longer periods, such as digital hazard maps and EU directives, have gradually reoriented FRM strategies. Institution-based self-reinforcing mechanisms are more prevalent than technology-based self-reinforcing mechanisms. Established actor coalitions combined with institutional density illustrate how those in charge uphold a path to defend their position, power and resources. Our recommendations for how to overcome path dependency in FRM governance are: encourage niche experiments, link FRM more closely with climate change adaptation, revise the national policy framework towards polycentric governance approaches and improve professional training., Regional Environmental Change, 23 (1), ISSN:1436-3798, ISSN:1436-378X

As protective forests have a major control function on runoff and erosion, they directly affect the risk from hydrogeomorphic processes such as sediment transport processes or debris flows. In this context, future scenarios of climate-related canopy disturbances and their influence on the protective effect remain, however, an unsolved problem. With the individual-based forest landscape and disturbance model iLand, an ensemble of forest landscape simulations was carried out and the effects of future changes in natural disturbance regimes were evaluated. To determine peak runoff, hydrological simulations have been conducted, using the conceptual hydrological model ZEMOKOST as well as the deterministic model GEOtop. Effects of forest disturbances on hillslope stability were investigated, based on a modified Coulomb landslide model. Our results suggest no influence of the disturbance regime on the runoff. The climate-related increase in the frequency of disturbances is not reflected in increased runoff during the period under consideration. Contrary, slope stability analyses indicate that the availability of shallow landslides in steep forested torrent catchments might be decreased by the occurrence of disturbances – especially for a warm and dry climate projection. Canopy disturbances seem to accelerate the adaptation of tree species to future climate conditions, which is likely to be accompanied by a change in root systems away from flat roots that currently predominate in torrential catchments. In terms of managing the protective effect of forests against shallow landslides, such natural disturbances can thus be considered as positive interventions in the existing forest ecosystem by promoting natural succession.

Socio-hydrology has become an important platform for discussion and exchange in current water research. A key challenge is the integration of the social into socio-hydrological logic. To date, most...

ZusammenfassungKosten-Nutzen-Analysen im Hochwassermanagement verwenden zur Beurteilung von Schutzkonzepten meist den physischen Schaden als Hauptkriterium. Dies kann zu einer ungleichen räumlichen Entwicklung führen, da in strukturschwachen Gemeinden meist weit geringere monetäre Werte gefährdet sind als in verdichteten Siedlungszentren. Der folgende Beitrag zeigt den Zusammenhang zwischen sozialer Gerechtigkeit und Kosten-Nutzen-Analyse und schlägt vor, wie strukturschwache Gemeinden besser in einem neuen Konzept der Kosten-Nutzen-Analyse abgebildet werden könnten, indem im Entscheidungsprozess soziale und psychologische Merkmale der Betroffenen mitberücksichtigt werden. Diese Erweiterung führt dazu, dass insbesondere Gemeinden in strukturschwachen Gebieten die Möglichkeit haben, einen Hochwasserschutz rascher umzusetzen. Mit diesem Beitrag möchten wir nicht nur die Bedeutung der sozialen und psychologischen Indikatoren im Hochwassermanagement aufzeigen, sondern auch, wie der Entscheidungsprozess in Zukunft gerechter gestaltet werden kann.

Flood risk management has developed a large inventory of potential actions to climate-related hazards. Within this wide array of measures, managed retreat of communities at risk is usually only taken into account if other strategies are ineffective or unavailable. Communities who are affected by managed retreat are confronted with radical changes in their livelihood. However, managed retreat is highly contested. The use of managed retreat includes not only the relocation of house owners but also has the challenge that it discriminates between landowners as some gain and others lose. Therefore, managed retreat raises issues of social justice. To mitigate the impact on land, compensation plays a crucial role in flood risk management. The level and kind of compensation varies between countries across the globe. In this paper, we compare two different policy compensation frameworks in two European countries: Austria and England. The comparative study shows how different compensation schemes affect social justice, both in terms of substantive distributions but also in terms of procedural justice.

Demographic trends across Europe indicate that many regions face sustained population decline due to aging and out-migration. Rural regions are often prone to flood hazards and have repeatedly been affected by damaging events in the past. However, we lack in-depth knowledge about how demographic trends challenge their capacities, abilities, and plans to manage flood risks. In this paper, we aim to close this gap. We employed a mixed-methods approach in the Gailtal-region in Carinthia (Austria), which combines the assessment of exposure to flood risk, social vulnerability, coping ability and adaptation capacity, as well as a discourse analysis. This comprehensive approach was designed to assess how demographic change impacts flood risk management. The findings do not support the hypothesis that population decline increases communities’ social vulnerability and reduces their coping ability and adaptation capacity. Additionally, the selected municipalities showed a strong increase in exposure. This is an example of the exposure paradox, which describes the phenomenon that settlement and population dynamics are not interconnected at all, especially in regions with a limited share of suitable land. Finally, our results show that current flood risk management and the corresponding social and political discourse mainly neglect the challenge of population decline. Overall, this study indicates that public administrations need to address the challenges of weak communities in flood risk management and consider how they might empower local authorities and citizens to adapt to future events – in full consideration of the demographic trends they have to expect.

Every year, thousands of people around the world who face unequal access to political and social power and resources lose their lives and/or livelihoods in natural hazard events. As a result, the reduction of vulnerability has become a central concern of humanitarian actors. This paper analyses the impact of humanitarian assistance on vulnerabilities in Nepal following the Gorkha earthquake on 25 April 2015. The causes and manifestations of vulnerability before and after the disaster are determined through the application of the Pressure and Release model and the adoption of a mixed-methods research approach. The findings of the study reveal that 20 months after the earthquake, humanitarian assistance had not had any long-term positive influences on the root causes of the phenomenon, and that vulnerabilities at the micro level could be resolved in part. To diminish the extent of disasters in the future, however, the fundamental reasons for the vulnerability have to be addressed better.

Strategic land use planning assumes a pivotal role in flood risk management. By using formal instruments, spatial planning can (i) legally secure areas for flood retention or other flood protection measures (hazard reduction) as well as (ii) regulate settlement development in hazard areas and ensure flood-adapted land uses (damage prevention). The interrelations between upstream and downstream riparian areas in flood risk management, however, require regional or catchment-oriented approaches in strategic land use planning to better coordinate land development options along rivers. This paper examines two strategic planning instruments in Austrian flood risk management. The two instruments – Blauzone Rheintal in Vorarlberg and Schutzwasserwirtschaftlicher Raumentwicklungsplan (SREP) in Carinthia – were developed by water authorities and spatial planning departments to prevent settlement growth in flood-prone areas and to secure land for flood protection schemes. Despite having similar problems in their backgrounds and objectives, the implementation processes of these instruments differ significantly: while the Blauzone Rheintal was formalized as a legally binding regional land use plan, the SREP was not developed beyond the pilot stage. This paper identifies important contextual conditions and lessons learned to facilitate the scaling-up and replication of catchment-oriented spatial planning instruments in other flood-prone regions.

Zusammenfassung Der demografische Wandel stellt eine komplexe Herausforderung für den territorialen und sozialen Zusammenhalt in unserer Gesellschaft dar. Dies deshalb, weil die Teilräume Österreichs in unterschiedlichem Maße von Veränderungen der Bevölkerungsgröße und der altersstrukturellen Zusammensetzung betroffen sind. Die bedarfsgerechte Planung und Bereitstellung von sozialer Infrastruktur wird auch aufgrund der Veränderungen der Haushaltsstrukturen und der Heterogenisierung der Bevölkerung infolge internationaler Zuwanderung zunehmend zur Herausforderung. Dieser Beitrag untersucht die Auswirkungen des demografischen Wandels auf die soziale Infrastruktur im Bereich des Hochwasserrisikomanagements aus Sicht von Expert*innen aus dem Gesundheits- und Sozialbereich. 17 Expert*innen aus verschiedenen Bundesländern und Tätigkeitsbereichen beteiligten sich an einer schriftlichen Befragung im Frühjahr 2020. Sie beantworteten einen 29 Fragen umfassenden Fragenkatalog zu den Bedeutungszusammenhängen zwischen dem demografischen Wandel und dem Hochwasserrisikomanagement und gaben Empfehlungen für den künftigen Umgang mit dem Thema Demografie in den Risikomanagementkonzepten ab. Die Ergebnisse zeigen, dass beiden Themenfeldern eine hohe Relevanz zugeschrieben wird, diese jedoch tendenziell oberflächlich skizziert werden. Als Erklärung hierfür kann der Mangel an integrativer Zusammenarbeit zwischen den verschiedenen Fachdisziplinen angenommen werden. Dies wiederum führt dazu, dass man in diesem Politikfeld vom erklärten Ziel der WHO, nämlich der „Health-in-all-policies“, noch ein Stück weit entfernt ist.

Given the investments that local, regional, and national governments have already made in mitigation and may consider in the future, it is crucial to assess mitigation effectiveness across all scales and determine which strategies are the most appropriate. This is particularly relevant as mitigation is viewed increasingly as a vital action for which investments and the resulting benefits must be evaluated and justified. It is fundamental to determine which measures are the most effective in optimising the response to floods in local communities. The study analyses the current state of knowledge on flood mitigation and reviews what methodologies have been applied in order to assess mitigation effectiveness and positive cost-benefit ratio (CBR). The growing body of literature has shown that losses from natural hazards can be significantly reduced when one or more mitigation techniques are put into practice. Moreover, an effective response to floods requires the contribution of flood-prone households and their local community, known as the bottom-up approach, in order to apply risk management strategies to increase community resilience. The results demonstrate that effectiveness increases when integrated approaches are implemented. In particular, the combination of top-down and bottom-up solutions can provide the best results in terms of socio-economic assessments. The study found that the commitment of both public and private stakeholders was of vital importance in achieving good flood mitigation levels, thus, mitigation must be seen as a joint effort between these actors. The paper also provides key findings from literature and recommendations for further research.

This contribution explores the conceptual and empirical linkages between population dynamics and natural hazard risk management (NHRM). Following a review of the international scholarly literature, we conduct a mixed-methods approach in Austria, combining an online survey among policy makers and other stakeholders with a thematic analysis of policy documents. The aim is to investigate the practical relevance of socio-demographic change in Austria’s NHRM. The study shows that many hazard-prone regions in Austria face population change, in particular demographic ageing and population decline. In addition, our findings from the online survey demonstrate the relevance of population dynamics in NHRM, especially with regard to hazard response and recovery. Nonetheless, policy formulation in NHRM overwhelmingly disregards demographic change as a relevant factor. Accordingly, the study underscores the importance of future-oriented risk management strategies to better account for ongoing and expected socio-demographic changes.

This paper examines two leading questions of current German spatial-planning-research. The first question regards the significance of co-authorships in German-language spatial planning research, me...

ZusammenfassungDer demografische Wandel zählt zu einer der bedeutendsten Herausforderungen unserer Zeit. Demografische Veränderungen vollziehen sich auf unterschiedliche Weise und mit unterschiedlicher Dynamik: Alterung, Bevölkerungsrückgang, Veränderung der Haushaltsstrukturen und Zuwanderung. Wenngleich die steigende Lebenserwartung und die anhaltend niedrigen Geburtenraten langfristig zu einem wachsenden Anteil an älteren Menschen in der Gesamtbevölkerung führen, sind die unterschiedlichen Teilräume Stadt und Land in sehr unterschiedlichem Ausmaß (bereits) vom Bevölkerungsrückgang betroffen. Aufgrund seiner quantitativen Dimension und der sicht- und spürbaren Auswirkungen vor allem auf kleinräumiger bzw. lokaler Ebene – zu nennen sind hierbei vor allem die Unter- bzw. Überauslastung von Infrastruktur, der bauliche Leerstand und die sich einengenden finanziellen Handlungsspielräume der Gemeinden – wird der demografische Wandel als Phänomen bereits öffentlich wahrgenommen. Obgleich sich der demografische Wandel in vielerlei Hinsicht bereits manifestiert, wird ihm im Bereich des Hochwasserrisikomanagements sowohl in der wissenschaftlichen Auseinandersetzung als auch in der Politikgestaltung und -umsetzung bislang kaum Aufmerksamkeit geschenkt. Dieser Beitrag gibt einen Überblick über den Stand der Auseinandersetzung mit dem demografischen Wandel in Bezug auf Hochwasserrisikomanagement aus dem Blickwinkel von Expertinnen und Experten aus den Bereichen Naturgefahren- und Katastrophenmanagement sowie der Raumplanung. Die ExpertInnenumfrage zeigt, dass Zusammenhänge zwischen demografischem Wandel und dem Management von Hochwasserrisiken für die meisten Akteure in Österreich auf der Hand liegen und als sehr relevant für das zukünftige Hochwasserrisikomanagement eingestuft werden. Insbesondere die demografische Alterung und der Bevölkerungsrückgang, aber auch die anhaltenden Veränderungen in der Haushaltsstruktur (d. h. der zunehmende Anteil von Einpersonenhaushalten und Zweitwohnungen) werden in verschiedenen Phasen des Risikomanagementzyklus als zunehmend relevant eingeschätzt. Die Ergebnisse zeigen aber auch, dass in der gegenwärtigen Politikgestaltung und -umsetzung – und hier insbesondere bei der Planung – diese langfristigen Entwicklungen kaum berücksichtigt werden.

Recent examples of climate-driven catastrophes both internationally (e.g. US and Australian wildfires in 2020) and nationally in Africa or Europe, as well as climate scenarios highlight that climate change impacts will likely reach dimensions which pose substantive shocks to social, economic and ecological systems in the near future. At some point, this increased number of shocks will overstretch current individual and collective coping capacities. However, on the other side catastrophic shocks may enable the transformation to decarbonisation and resilience of our society, if the rebuilding phase after an event is used for a broad societal transformation process and not only for quickly bouncing back to the pre-shock situation. A rushed return to normality may come at the cost of forgoing lengthy and challenging transformation processes, which may ultimately reorient a system to higher resilience. Fast recovery from shocks typically mobilizes extensive resources but often lacks an integrated perspective on climate change adaptation and mitigation policies (‘adaptigation’) that could leverage synergies and build up for long-term responses to climate impacts. Instead, many policies implemented after shocks act in isolated or even competitive silos, cater to immediate demands by affected citizens and businesses, and have different goals, instruments, financial resources, administrative practices, time perspectives, or lack of imagination how to implement. The aim of the paper is therefore to illustrate how the transformative potential of shocks can be leveraged to lower carbon emissions, higher climate resilience and encompassing adaptigation policy. This contribution presents a conceptual framework that focuses on the interaction between the individual actors affected by a shock, and the policy instruments in place in the aftermath of a shock. We strive to learn from past and current reactions to inform the future with the aim of directing post-shock learning to transformation outcomes and to avoiding maladaptation, backfire or inaction pitfalls. The paper derives guidance how to leverage the transformative potential of shocks by dedicated policy action, in order to promote outcomes congruent with the Sustainable Development Goals and the targets of European and Austrian climate change mitigation and adaptation strategies. The conceptual framework can be expected to apply to a wide range of emerging, novel or familiar shocks.

Urban areas provide a range of benefits to sustain human livelihood and contribute to human well-being through urban ecosystem services. Open spaces in core urban areas of Kathmandu valley in Nepal carries multiple advantages of stimulating social cohesion, offers safe area immediately after a crisis induced by natural hazards, contributes in environmental improvement and mitigates urban flooding. In most urban areas of Nepal, unplanned urbanization has resulted in alteration of landscapes from permeable vegetated surfaces to a series of impervious interconnected surfaces resulting in large quantities of stormwater runoff, requiring wider implementation of water sensitive urban design. After 2015 Gorkha earthquake, several blue-green infrastructure projects are implemented by local governments inside Kathmandu valley in open spaces. This paper presents application examples of green infrastructure projects and through case studies provides a framework for optimization of green infrastructure systems in Nepal. The paper also provides a practitioners perspective on the current state of knowledge, highlights technical challenges in green infrastructure implementation in Kathmandu and points out recommendations to overcome them.

To achieve a more flood-resilient society, it is essential to involve citizens. Therefore, new instruments, such as tailor-made advice for homeowners, are being developed to inform homeowners about adaptive strategies in building to motivate them to implement these measures. This article evaluates if public–private interactions, such as tailored advice, change risk behaviour and therefore increase flood resilience among homeowners. The article conducted semi-structured interviews with homeowners who had received advice as well as involved experts in two case study regions in Europe: Flanders in Belgium and Vorarlberg in Austria. The results show how the tailored advice helps homeowners who are already aware of flood risks and provides them with answers on how to adapt a house. However, the tool seems to lack the ability to inform and “recruit” new groups of homeowners who are not as familiar with flood risks. As such, this article concludes that this initiative has a relatively low impact in raising flood risk awareness among homeowners but may be more successful in serving as a tool that suggests tailored property-level flood risk adaptation measures for those who are already aware. Alternatively, more automated tailored information systems might be more efficient for unaware homeowners.

Damages due to extreme hydro-metrological events request for additional efforts to enhance the implementation of property level flood risk adaptation (PLFRA) measures. Although a highly effective l...

This article aims to analyze the legal framework for flood risk management in Austria, focusing on planning. Austria’s legal basis for flood risk management is fairly complex because its federal or...

In the face of increasingly frequent and severe extreme weather events due to climate change, merely top-down governance approaches are increasingly found inadequate and ineffective. Recent climate change adaptation policy strives to promote bottom-up, citizen-driven initiatives to improve local resilience. How and under what conditions citizens may engage in collective action remains unclear, however. We employ a mixed-methods approach in Eastern Tyrol, Austria, combining stakeholder workshops with a survey of 216 citizens at risk. Results show that bottom-up citizen initiatives can provide multiple benefits, such as increasing risk awareness and local adaptive capacities. While citizens are open-minded to assuming a broad range of activities and responsibilities, local stakeholders in natural hazard management prefer to limit civic engagement to support roles, mostly during recovery from a natural hazard event. Citizen initiatives tend to emerge in communities with weak institutional capital. This may lead to conflicts with existing institutions over allocation of competences and power. Contrastingly, social and human forms of capital support the formation of initiatives; however, low willingness of citizens to assume leadership positions may be a bottleneck for sustained initiatives. Public administration and emergency organisations should address current institutional barriers. They should empower and allow citizens to act autonomously.

A key challenge of hazard risk management is finding novel ways to respond to future extremes amid increasing vulnerability. Societal transformation in the context of multi-functional protection schemes offers potential in this regard. However, the drivers and barriers of societal transformation in hazard management are poorly understood. Here we interrogate drivers and barriers of societal transformation in natural hazard management through case studies in Austria, France and Ireland focusing on attempts to integrate multi-functional protection schemes in the context of flood and avalanche hazards. We conducted qualitative semi-structured interviews with key stakeholders connected to proposed transformative strategies in the selected case studies. We find that transformative approaches have been mainly supported by local initiatives instigated by local governments, residents, or NGOs with the aim of complementing conventional hazard management policies. Our analysis shows that local actors and stakeholders often pursue initiatives to address local problems or to seize local opportunities rather than to contribute to a broader societal transformation. According to our findings, key drivers of community-based initiatives with multiple functionality and use include: (i) lack of funding, (ii) lack of legal protection or (iii) lack of space, where classical risk management measures can no longer respond to new circumstances. In contrast, key barriers relate to: (i) lack of local capacities, (ii) lack of local political support and (iii) technological challenges in the implementation phase. These insights support European regions currently working on the implementation of climate change adaptation strategies arising from natural hazards

International audience; Mountains are highly sensitive to climate change. Their elevated areas provide essential ecosystem services both for the surrounding mountainous regions and particularly for adjacent lowlands. Impacts of a warmer climate affect these services and have negative consequences on the supply of water, on biodiversity and on protection from natural hazards. Mountain social-ecological systems are affected by these changes, which also influence communities' risk perception and responses to changing climate conditions. Therefore, to understand individual and societal responses to climate change in mountain areas, aspects and drivers of risk perception need to be scrutinised. This article presents the findings of a literature review of recent English language publications on risk perception in connection to climate change and related natural hazards in mountain regions worldwide. Studies were selected from recorded entries in JSTOR, Science Direct, Scopus and Web of Science covering the period 2000-2019 and analysed in two steps (structured exploratory analysis, n=249 and in-depth analysis, n=72) with respect to the studies' research question, methodology, geographical scope and risk perception drivers. The review reveals that socio-demographic factors, like gender, age and personal experiences, have a crucial impact on individual risk perception. Some of the less tangible but nevertheless decisive factors are important in mountain regions such as place attachment and socio-cultural practices. In conclusion, there is however little information in the literature which addresses the specific situation of risk perception in mountain areas and its influence on communities' responses to environmental changes. Further, we observed a strong gap concerning the integration of indigenous knowledge in risk perception research. Many studies overlook or oversimplify local knowledge and the cultural dimensions of risk perception. Based on these results, the paper identifies several gaps in research and knowledge which may influence the design of climate risk management strategies as well as on their successful implementation.