Ecosystem-based solutions for gravitational natural hazard mitigation: a review on the use of protection forests for disaster risk reduction in mountain areas

<p>Mountain regions are affected by various natural hazards, of which gravitational mass movements are some of the most important ones. Due to the accumulation of settlements and intense economic activities in exposed areas, mountain regions such as the Alps constitute a risk hot-spot. The threat posed by gravitational natural hazards to human activities affirms the strong need for risk management, particularly for prevention. Structural measures are increasingly applied in combination with land use planning and ecosystem-based solutions. In particular, ecosystem-based solutions not only prevent the initiation of the processes but also act as a protective barrier. These green measures have been gaining an increasing attention also due to their adaptability to respond to the challenges posed by global change. Systematic reviews on how ecosystems can be used for disaster risk reduction have been carried out; however, their focus is on urban and coastal environments or on specific natural hazards such as shallow landslides. Up to now, there is no systematic review which addresses the role of ecosystems in disaster risk reduction regarding multiple gravitational natural hazards in mountain areas.</p><p>This contribution provides such a systematic review aimed at filling this knowledge gap to give a direction for future research. The review is composed of two main parts: a quantitative bibliometric analysis followed by a qualitative review. The quantitative part, based on the Scopus peer-reviewed database, aimed to investigate the publication trend on the ecosystem-based solutions for gravitational natural hazard mitigation by comparing it with the general trend of published scientific documents. The bibliometric analysis also served as a basis to select most relevant articles on which to conduct the subsequent qualitative analysis. The content of the so selected publications was analysed qualitatively the following  predefined criteria: the natural hazards addressed, the features of the ecosystem (i.e. forest species composition, management activities, effectiveness in risk mitigation), the development of alternative scenarios to test different hypothesis, the degree of stakeholder involvement, and the monetary evaluation of the measures (i.e. comparing them to structural measures). Results show a sharp increase in the number of publications on the topic from 1980 to 2018 compared to the overall number of documents published on Scopus. Although the overall topic is gaining more attention in scientific literature, the in-depth qualitative analysis revealed that research still pays little attention to stakeholder involvement and an economic evaluation of measures. We conclude that filling this research gap might help to foster a wider adoption of ecosystem-based solutions for disaster risk reduction across mountain areas.</p>

Landslide dam susceptibility in the Austrian Alps inferred from modelled landslides, potential valley damming and lake formation

<p>In mountain landscapes, landslides often block river courses. Although landslides are well-known threats, the risks imposed by landslide dams are sometimes neglected. The impeding of a river can lead to the submergence of parts of the upstream valley and a failure of the dam can flood downstream terrain in a catastrophic event.</p><p>Our aim is two-fold: we are interested in creating a landslide dam susceptibility map relying on <span>model</span><span>led</span><span> landslides and resulting damming of valleys and formation of lakes</span>, and in studying the relation between the occurrence of landslide dams and lithology.</p><p>Landslide susceptibility maps are a common tool for natural hazard mitigation, but landslide dam susceptibility maps are rarely produced. Several simple indices (Blockage Index, Backstow Index) have been developed to predict the obstruction capacity and stability of landslides on a river from landslide and catchment characteristics (landslide volume, catchment area, dam height etc.). However, those methods were applied on observed landslides, and did not consider landslide susceptibility. Here, we created a first modelling-based landslide dam susceptibility map and compared it to the results provided by the indices.</p><p>Although the relation between lithology and landsliding has been thoroughly studied, no connection with dam formation has been highlighted so far. Lithology has an impact on various characteristics of the landslide, including its volume, and also influences valley geometry. We investigated if some alpine lithological units are more prone to landslide dam formation than others.</p><p><span>In our modelling approach we used a </span><span>10 m </span><span>DEM of</span> the Austrian Alps and <span>stochastically triggered landslides based on </span><span>slope</span> <span>thresholds</span>. We then simulated the runout of the landslides using a fluid flow solver. For each landslide deposit we computed the maximum dammed volume by filling the landslide-dammed DEM, and compared those volumes to the lithology. We also tested the different theoretical geomorphological indices to predict the impounding of the river and compared them to the actual results provided by our method.</p>

Natural hazard mitigation strategies review: Actor–network theory and the eco-based approach understanding in Zimbabwe

This paper presents the literature reviewed on the evolution of the natural hazard mitigation perspective and an overview of its progression to date. The article uses information taken from diverse sources such as a globally accepted scientific databases Google Scholar (http://www.scholar.google.co.in), Scopus (http://www.scopus.com), Science Direct (http://www.sciencedirect.com), SpringerLink (http://www.springer.co.in) and Wiley (http://www.onlinelibrary.wiley.com); conference proceedings; theses; abstracts; and impact and non-indexed journals. It demonstrates how the actor–network theory (ANT) theoretical framework can be applicable to Muzarabani in Zimbabwe as a tool for analysing and elaborating hazard mitigation strategies. Actor–network theory is gradually becoming influential but is still a bone of contention, mainly because of its radical approach. Actor–network theory treats humans and non-humans as equal actors. In spite of its limitations, studies have shown that an ANT-grounded approach is useful in providing a framework for the comprehension of the complexities of daily life during natural hazard episodes and the dynamic role of Ziziphus mauritiana in the network in Muzarabani, Zimbabwe. The theory can demonstrate its importance in respect of how social results are produced as a result of linkages among diverse actors (human and non-human) in a network. The article argues that if ANT is used logically it is useful in examining eco-based natural hazard mitigation and resilience approaches in semi-arid regions.

Technological innovation, social learning and natural hazard mitigation: evidence on earthquake fatalities

How do people learn from disasters? Do they constantly develop and accumulate new knowledge that enables them to address recurrent disaster risks? This paper investigates whether social learning and, in particular, the development of earthquake-mitigating technologies reduces earthquake-induced fatalities. Combining patent data with a global cross-section of 894 earthquakes that occurred between 1980 and 2010, we find that countries with more disaster-mitigating innovations and more earthquake exposure in the past suffer fewer fatalities. This study is the first to empirically examine the role of technological change and social learning in disaster mitigation. It sheds light on knowledge as a key element of adaptive capacity, and suggests the importance of incorporating technology development into a long-term hazard mitigation and adaptation policy. The paper also contributes to the empirical disaster literature as the first to address the problem of missing data on disaster losses.

A Burning Problem: Social Dynamics of Disaster Risk Reduction through Wildfire Mitigation

Disasters result from hazards affecting vulnerable people. Most disasters research by anthropologists focuses on vulnerability; this article focuses on natural hazards. We use the case of wildfire mitigation on United States Forest Service lands in the northwestern United States to examine social, political, and economic variables at multiple scales that influence fire hazard and risk reduction treatments and their effectiveness. Variables highlighted include policy direction to prioritize wildfire risk reduction in the wildland-urban interface, laws and policies that make treating fuels in some national forest land management allocations challenging, social and political constraints on using prescribed fire, agency budget and target pressures, and integrating fire hazard reduction into forest management projects having multiple objectives. These variables compromise the effectiveness of wildfire mitigation treatments. Understanding the social dynamics of natural hazard mitigation is important because they affect its outcomes, creating differential exposure to natural hazards—one component of social vulnerability. Interdisciplinary research to identify how the social dynamics of natural hazard mitigation influence hazard reduction outcomes can contribute to more informed and effective approaches to disaster risk reduction.

Bridging the Gap: Hazard Mitigation in the Global Context

Natural hazard mitigation is a recent field in name only. For decades various professionals have been practicing hazard mitigation: for example, emergency managers have been working with architects and city planners to update building codes for disaster-resistant construction, civil engineers have been working with local officials to design flood-resistant urban drainage systems, and foresters have been working with state officials to enact more effective prescribed burning practices. Yet most often, natural hazard mitigation has taken place as isolated activities scattered within the daily duties of diverse professions – an accidentally cross-disciplinary effort recognized as vitally important to protect individuals and communities, yet not recognized as its own multidisciplinary field. The crucial importance of natural hazard mitigation requires a more coherent approach, with consistent and accessible technical information and training, formal and informal discourse among hazard mitigation professionals, interaction with a greater public awareness of the social components, and recognition of hazard mitigation as a profession in its own right. Simultaneously, hazard mitigation professionals need to strengthen their multidisciplinary tendencies and continue to collaborate with other key fields, such as public health and the various sciences. Today many professionals are starting to bridge the gaps between disaster risk reduction, hazard mitigation, and climate adaptation. This article discusses the benefits of emergency management professionals working with others in community partnerships to achieve resilience