Population dynamics and natural hazard risk management: conceptual and practical linkages for the case of Austrian policy making

Natural Hazards - This contribution explores the conceptual and empirical linkages between population dynamics and natural hazard risk management (NHRM). Following a review of the international...     

A structured approach to enhance flood hazard assessment in mountain streams

An evidence-based flood hazard analysis in mountain streams requires the identification and the quantitative characterisation of multiple possible processes. These processes result from specific triggering mechanisms on the hillslopes (i.e. landslides, debris flows), in-channel morphodynamic processes associated with sudden bed changes and stochastic processes taking place at critical stream configurations (e.g. occlusion of bridges, failure of levees). From a hazard assessment perspective, such possible processes are related to considerable uncertainties underlying the hydrological cause-effect chains. Overcoming these uncertainties still remains a major challenge in hazard and risk assessment and represents a necessary condition for a reliable spatial representation of process intensities and the associated probabilities. As a result of an accurate analysis of the conceptual flaws present in the procedures currently employed for hazard mapping in South Tyrol (Italy) and Carinthia (Austria), we propose a structured approach as a means to enhance the integration of hillslope, morphodynamic and stochastic processes into conventional flood hazard prediction for mountain basins. To this aim, a functional distinction is introduced between prevailing one-dimensional and two-dimensional process propagation domains, i.e., between confined and semi- to unconfined stream segments. The former domains are mostly responsible for the generation of water, sediment and wood fluxes, and the latter are where flooding of inactive channel areas (i.e. alluvial fans, floodplains) can occur. For the 1D process propagation domain, we discuss how to carry out a process routing along the stream system and how to integrate numerical models output with expert judgement in order to derive consistent event scenarios, thus providing a consistent quantification of the input variables needed for the associated 2D domains. Within these latter domains, two main types of spatial sub-domains can be identified based on the predictability of their dynamics, i.e., stochastic and quasi-deterministic. Advantages and limitations offered by this methodology are finally discussed with respect to hazard and risk assessment in mountain basins.     

Integrated seismic hazard evaluation and disaster management approach for Turkey

A significant proportion of the urban areas in Turkey is subject to high seismic risk. An important step for seismic risk mitigation is to define the hazard and damage after an earthquake. This paper proposes an integrated seismic hazard assessment and disaster management processes for Turkey. The proposed methodology utilizes information technologies in its seismic assessment component that provides fast results for assessment. First, image process methodology by using satellite images was implemented in the seismic assessment process for fast evaluation right after an earthquake. Second, the seismic assessment process was integrated with disaster management process. As a result, through integrated seismic hazard evaluation and disaster management procedure, an effective, fast and dependable estimation of loss for Turkey was planned.     

Landslides in Emilia-Romagna region (Italy): strategies for hazard assessment and risk management

In Emilia-Romagna, over 32,000 landslide bodies cover one-fifth of the hilly and mountainous territory. The majority of them originated as earth-flows after the last glacial maximum and grew during the rainiest periods of the Holocene through the superimposition of new earth-flows. Reactivation of these large landslides is the main problem the geologists of Emilia-Romagna are facing now. Intense and/or prolonged precipitation play a major role as triggering factors in reactivating landslide bodies, but also the importance of snowmelt is suggested by the monthly distribution of landslide events. Almost all the present-day landslide activity is due to the reactivation of pre-existing landslide bodies. Consequently, territorial planning and geo-thematic cartography are fundamental tools for the reduction of risk. The Emilia-Romagna geo-thematic cartography (1:10,000) is legally binding and regulates land use in regional, municipal and basin plans.     

断裂性质与滑坡分布的关系——以汶川地震中的大型滑坡为例

美姑河流域地处全球滑坡灾害密集的云贵高原与川西南山地过渡带,该地区因地貌类型特殊,大型-巨型滑坡数量多、危害重、成因机理复杂,成为河谷区重大工程和城镇建设的安全隐患。笔者在国内外古滑坡研究成果分析的基础上,总结了美姑河流域古滑坡时空展布、滑坡对顺构造地貌响应、滑坡孕灾-控灾机理,滑坡成灾模式与主控因素等方面的研究进展。结合当前滑坡防灾减灾实际需求,提出美姑河流域顺构造地貌控制下古滑坡孕灾模式研究的3个优选方向：(1)不同发育强度的顺构造地貌对滑坡孕灾-控灾模式,(2)构造差异隆升对顺构造地貌区大型滑坡发育的孕灾模式,(3)通过古滑坡年代学研究建立断裂、褶皱、古地震和古气候变化与滑坡发育的对应联系。破解这些研究方向的关键科学问题,将为西南山区古滑坡研究及防灾减灾起到积极指导作用。     

Probability-weighted hazard maps for comparing different flood risk management strategies: a case study

The study proposes an original methodology for producing probability-weighted hazard maps based on an ensemble of numerical simulations. These maps enable one to compare different strategies for flood risk management. The methodology was applied over a 270-km² flood-prone area close to the left levee system of a 28-km reach of the river Reno (Northern Central Italy). This reach is characterised by the presence of a weir that allows controlled flooding of a large flood-prone area during major events. The proposed probability-weighted hazard maps can be used to evaluate how a structural measure such as the mentioned weir alters the spatial variability of flood hazard in the study area. This article shows an application by constructing two different flood hazard maps: a first one which neglects the presence of the weir using a regular levee system instead, and a second one that reflects the actual geometry with the weir. Flood hazard maps were generated by combining the results of several inundation scenarios, simulated by coupling 1D- and 2D-hydrodynamic models.     

Flood risk management,an approach to managing cross-border hazards

River flooding is a serious hazard in the UK with interest driven by recent widespread events. This paper reviews different approaches to flood risk management and the borders (physical, conceptual and organisational) that are involved. The paper showcases a multi-method approach to negotiating flood risk management interventions. We address three fundamental issues around flood risk management: differences and similarities between a variety of approaches; how different approaches work across borders between professionals, lay people, organisations and between different planning regimes; and, whether the science evidence base is adequate to support different types of flood risk management. We explore these issues through a case study on the River Tweed using Q methodology, community mapping and focus groups, participatory GIS, and interviews, which enabled co-production of knowledge around possible interventions to manage flooding. Our research demonstrated that excellent networks of practice exist to make decisions about flood risk management in the Scottish–English borders. Physical and organisational borders were continually traversed in practice. There was an overwhelming desire from professional flood managers and local communities for an alternative to simply structural methods of flood management. People were keen to make use of the ability of catchments to store water, even if land needed to be sacrificed to do so. There was no difference in the desire to embrace natural flood management approaches between people with different roles in flood management, expertise, training or based in different locations. Thus conceptual borders were also crossed effectively in practice.     

Flood risk perceptions and spatial multi-criteria analysis: an exploratory research for hazard mitigation

The conventional method of risk analysis (with risk as a product of probability and consequences) does not allow for a pluralistic approach that includes the various risk perceptions of stakeholders or lay people within a given social system. This article introduces a methodology that combines the virtues of three different methods: the quantifiable conventional approach to risk; the taxonomic analysis of perceived risk; and the analytical framework of a spatial multi-criteria analysis. This combination of methods is applied to the case study ‘Ebro Delta’ in Spain as part of the European sixth framework project ‘Floodsite’. First, a typology for flood hazards is developed based on individual and/or stakeholders’ judgements. Awareness, worry and preparedness are the three characteristics that typify a community to reflect various levels of ignorance, perceived security, perceived control or desired risk reduction. Applying ‘worry’ as the central characteristic, a trade-off is hypothesized between Worry and the benefits groups in society receive from a risky situation. Second, this trade-off is applied in Spatial Multi-Criteria Analysis (SMCA). MCA is the vehicle that often accompanies participatory processes, where governmental bodies have to decide on issues in which local stakeholders have a say. By using risk perception-scores as weights in a standard MCA procedure a new decision framework for risk assessment is developed. Finally, the case of sea-level rise in the Ebro Delta in Spain serves as an illustration of the applied methodology. Risk perception information has been collected with help of an on-site survey. Risk perception enters the multi-criteria analysis as complementary weights for the criteria risk and benefit. The results of the survey are applied to a set of scenarios representing both sea-level rise and land subsidence for a time span of 50 years. Land use alternatives have been presented to stakeholders in order to provide the regional decision maker with societal preferences for handling risk. Even with limited resources a characteristic ‘risk profile’ could be drawn that enables the decision maker to develop a suitable land use policy.     

A DEA-based framework for innovation risk management in production systems: case study of innovative activities in industries

This paper provides a framework for evaluation of innovation risk based on Data Envelopment Analysis (DEA) method. In this framework, the common paradigms of innovation risk are considered as inputs and the various types of innovation are as outputs. These risk paradigms were extracted from valid resources of innovation sector, and a comprehensive classification of innovation types, provided by OECD, was used as outputs category. The relationship between these inputs and outputs is assessed by DEA method based on the CCR model. In this survey, the framework was implemented for innovative activities in various industries, and the results lead us to draw the “Innovation Path” that shows the development direction for each understudy cases. The Innovation Path that is derived from the numerical results shows the numerical goal and useful information about innovation management systems. This path can be used by industrial managers, decision makers and strategists to take the best decision and design the practical strategies to manage the innovation risks.     

ICL/IPL activities in West Africa: landslide risk assessment and hazard mapping approach

The ICL/IPL Project achieved results in capacity building, investigation of landslides in West Africa and also evaluated some other slope movements in the region. These include the catastrophic rock–debris avalanche at the Cameroon–Nigeria border and the Iva Valley landslides in Enugu. During the avalanche, an estimated 100 M m³ of rock and debris was moved more than 2 km from the source of the slide at 600 m above sea level to the toe in the valley in a few minutes. The materials range from mud and soil debris to blocks of rocks up to 20 m in diameter. The grain size of moved material tended to increase upslope and closer to the head scarp though it tended to decrease again close to and at the source area. Nature and composition of the basement bedrock with foliation planes dipping in the direction of slope, dominant joint sets oriented perpendicularly to the foliation, the nature of weathered material and high relief were strong factors in the avalanche. Field studies identified 43 landslides at the Iva Valley area of Enugu state, which were shallow, short run-out movements with slip-surface depth less than 2 m. The shallow slides and the avalanche are triggered by water infiltration in slopes with high topographic gradient. The soil saturation leads to a reduction of the shear strength of the soil because of a rise in pore water pressure. These landslides are known to occur during or after intense rainfalls at the beginning or at the tail end of rainy season.     

A systematic approach for the assessment of flooding hazard and risk associated with a landslide dam

Inundation caused by landslide dams may occur in the upstream and downstream of the dams. A proper flooding hazard assessment is required for reaction planning and decision-making to mitigate possible flooding hazards caused by landslide dams. Both quick and detailed procedures can be used to evaluate inundation hazards, depending on the available time and information. This paper presents a systematic approach for the assessment of inundation hazards and risks caused by landslide dam formation and breaches. The approach includes the evaluation of dam-breach probability, assessment of upstream inundation hazard, assessment of downstream inundation hazard, and the classification of flooding risk. The proposed assessment of upstream inundation estimates the potential region of inundation and predicts the overtopping time. The risk level of downstream flooding is evaluated using a joint consideration of the breach probability of a landslide dam and the level of flooding hazard, which is classified using a flooding hazard index that indicates the risk of potential inundation. This paper proposes both quick and detailed procedures for the assessments of inundation in both the upstream and downstream of a landslide dam. An example of a landslide dam case study in southern Taiwan was used to demonstrate the applicability of the systematic approach.     

Transboundary hazard risk: the Gobi desert paradigm

Transboundary hazard risk reflects how different societies interact with disaster in a shared landscape. In the Gobi desert of northern China and southern Mongolia recurring drought, extreme cold, wind and dust storms are the dominant hazards yet disasters vary significantly in the two countries. Research examined national approaches to environmental engagement and livelihoods in the desert through an assessment of disaster risk in two Gobi communities; farmers in Gansu Province, China, and herders in Dundgov and Omnogov Provinces, Mongolia. Exposure and resilience was evaluated and work examined how risk factors are shaped by policy, economics, culture and social memory. Comparison between two state systems reveals how disaster risk and vulnerability are shaped as much by human action as by the physical climatic event. China stressed government-led disaster management whilst Mongolia emphasised adaptation to hazards. Integrating multiple divisions within a hazard zone is essential to address risk reduction; without this disaster mitigation remains state-specific and lacks applicability to a wider area or global context.     

Correction to: A historical geomorphological approach to flood hazard management along the shore of an alpine lake (northern Italy)

Natural Hazards - This correction stands to correct mistakes presented in the original article due to a lag in the e-proofing system and the correction handling for this article. The original...     

A historical geomorphological approach to flood hazard management along the shore of an alpine lake (northern Italy)

A project to develop a flood hazard management plan along the east shore of Lago Maggiore was carried out. Several municipal territories along a coastal stretch have been analysed, identifying the rate of water rise and the limits of the submerged areas. This study discusses the overall methodological approach and presents the results for Porto Valtravaglia, as a significant case study. The first step was a detailed analysis of historical events to locate the most frequently damaged sites. Thousands of historical documents on past floods were collected, selected and validated, to map the most vulnerable sites. The second step was a morphological analysis of the studied coastal stretch. Multi-temporal aerial snap-shots were used and field surveys were conducted to verify the reliability of the historical data and to identify the critical hydraulic conditions along the shore. The third step was a review of the general urban development plans of the 17 studied municipalities. Aerophotogrammetric and cadastral maps were used to evidence and define the eight classes of land use destinations. In addition, the floodable areas were divided into three vulnerability and exposure categories considering different peculiarities of social and working life. Finally, using GIS spatial analysis tools, these data were compiled into risk maps and wielded as the municipal emergency plans’ baseline scenarios. For each studied municipality was hypothesised the alarm thresholds upon which were activated the flood emergency procedures.

     

An innovative micro-scale approach for vulnerability and flood risk assessment with the application to property-level protection adoptions

Economic damage assessment for flood risk estimation is established in many countries, but attentions have been focused on macro- or meso-scale approaches and less on micro-scale approaches. Whilst the macro- or meso-scale approaches of flood damage assessment are suitable for regional- or national-oriented studies, micro-scale approaches are more suitable for cost–benefit analysis of engineered protection measures. Furthermore, there remains lack of systematic and automated approaches to estimate economic flood damage for multiple flood scenarios for the purpose of flood risk assessment. Studies on flood risk have also been driven by the assumption of stationary characteristic of flood hazard, hence the stationary-oriented vulnerability assessment. This study proposes a novel approach to assess vulnerability and flood risk and accounts for adaptability of the approach to nonstationary conditions of flood hazard. The approach is innovative in which an automated concurrent estimation of economic flood damage for a range of flood events on the basis of a micro-scale flood risk assessment is made possible. It accounts for the heterogeneous distribution of residential buildings of a community exposed to flood hazard. The feasibility of the methodology was tested using real historical flow records and spatial information of Teddington, London. Vulnerability curves and residual risk associated with a number of alternative extents of property-level protection adoptions are estimated by the application of the proposed methodology. It is found that the methodology has the capacity to provide valuable information on vulnerability and flood risk that can be integrated in a practical decision-making process for a reliable cost–benefit analysis of flood risk reduction options.     

Population dynamics and global change: the need for new conceptual maps

Current approaches to population: 1) focus too much on humans and not on their interactions over time with populations of other species; 2) focus too much on the number of humans and not on their differential resource use and environmental impact; 3) accept uncritically the assumptions and concepts of industrial society regarding the nature of progress and the neutrality of technologies, markets, and trade. Broader and more integrated approaches are needed to address current international and global realities and trends.