Flood risk management approaches have shifted toward the combination of both physical, engineered-centred and governance-based mitigation measures. Governance-based measures, previously perceived as ...a complement to structural measures, appear today prominent and, especially, are playing a dominant role in flood risk management. In the context of climate changes, the use of governance-based mitigation is believed to foster adaptability; governance-based mitigation measures may be changed along the way. However, the transition to governance measures, for the rural stakeholders in the Gironde estuary, raises some issues when it comes to their flexibility while implemented in combination with the existing structural measures. This paper analyses this combination in regard of the uncertainties related to climate changes.
Assessment of catchments water retention potential in the landscape is a common part of management plans as components of integrated flood risk management strategies. For forest land use, it has been ...stated that the promotion of sustainable forest management and the increase of forest land via afforestation will considerably improve flood retention. Notably, the latter should be efficient to re‐establish the natural water retention potential in anthropogenically disturbed river basins and to decrease the human‐made contribution to flood generation. However, due to obvious physical limitations (such as soil depth, porosity, and conductivity) and the frequent lack of available land for forest expansion, the role of afforestation in flood mitigation has been a topic of strong debate. This study assesses the ‘forest effect’ based on model calculations and suggests visualisations to communicate the results. For a catchment (6.8 ha) and two well‐founded land‐use scenarios, it could be shown that the peak reduction for flood events varies from 3% to 70% and is highly related to the event characteristics (especially pre‐event soil moisture). The cross compliance to other protection aims (i.e. water quality and soil protection) is part of the considerations.
PurposeClimate change has had serious consequences at the global and local levels, which has required more effective scientific studies and management measures for disaster risk reduction strategies. ...This paper aims to analyze and discuss the degree of institutional vulnerability in terms of disaster risk governance, with emphasis on non-structural measures taken in the municipality of Jaboatão dos Guararapes, Pernambuco, Brazil.Design/methodology/approachFive indicators were analyzed, composed of Planning and Management Instrument, Management Structure, Preventive Action, Multidisciplinary Work and Emergency Funds. It is worth highlighting the form application with government actors, involving technicians from strategic areas of the municipality and official reports analysis. It stands out the importance of non-structural measures to strengthen this governance.FindingsFrom the results of this study was noted that municipal management adopted measures to develop integrated planning, acting within the principles recommended in the Sendai framework (2015–2030), characterized as a medium degree of institutional vulnerability. Recommendations are suggested for the improvement of the entire governance system, according to the indicators and documents analyzed.Originality/valueThis article integrates a set of data and analyses relevant to the Disaster Risk Governance, regarding the assessment of institutional vulnerability with a view to non-structural actions. The importance and significance of the composed indicators allow measuring and evaluating institutional vulnerabilities. The methodology created fomented the production of scientific knowledge that allows employment in other municipalities.
Understanding the diversity and complexity of stand structure is important for managing the biodiversity of forest ecosystem, and stand structural diversity is essential for evaluating forest ...management activities. Based on the relationship of adjacent trees, a quantitative method of stand structure diversity is proposed to express the heterogeneity of stand structure in tree species, distribution pattern, species separation and size differentiation. In this study, we defined the diversity of structural unit types and derived a new index of forest structural diversity (SD′) employing the additivity principle of the Shannon–Weiner index. The efficiency of the index was verified by applying the new measure to sixteen field survey samples at different locations. The mountain rainforest in Hainan had the highest forest structural diversity, followed by broad-leaved Korean pine forests in Jiaohe (2), Jiaohe (1) and an oak-broadleaved mixed natural forest at Xiaolongshan (2). The SD′ values of plantations and pure natural forest were lower. The simulated data of different thinning methods and the intensity of broad-leaved Korean pine forests show that the new measure can reflect forest management changes on stand structure diversity. The value of SD′ compared with no treatments and the differences were greater as thinning intensity increased. The SD′ index provides minimum and maximum values for different structural unit types in forests to achieve a unified comparative basis for calculating forest structure diversity. It has the characteristics of the general diversity index and can well express the diversity of tree species, distribution pattern and size differentiation simultaneously. The SD′ index can not only calculate the structural diversity of mixed species forests but can also be used to calculate the structural diversity of pure forests. It can also be used to evaluate the change in stand structure diversity after management interventions.
The concept of flood risk management, promoted by the EU Floods Directive, tries to mitigate flood risks not only by structural, hydraulic engineering measures, but also by non-structural measures, ...like, e.g., land-use planning, warning and evacuation systems. However, few methods currently exist for the economic evaluation of such non-structural measures and, hence, their comparison with structural measures. The objective of this paper is to demonstrate the potential benefits of employing a wider range of economic appraisal methods for flood projects, in particular, it provides examples and applications of methodologies which may be employed to evaluate non-structural measures and their transaction costs. In two case studies at the Mulde River, Germany, two non-structural measures, a resettlement option and a warning system, are evaluated and compared with structural alternatives with regard to their effectiveness, cost-effectiveness and efficiency. Furthermore, a simple approach is tested in order to show the transaction costs of these measures. Case study results show that the choice of evaluation criteria can have a major impact on the assessment results. In this regard, efficiency as an evaluation criterion can be considered as superior to cost-effectiveness and effectiveness as it is also able to consider sufficiently the impacts of non-structural measures. Furthermore, case study results indicate that transaction costs could play an important role, especially with non-structural measures associated with land-use changes. This could explain why currently these kinds of measures are rarely selected by decision makers.
In the last years, natural hazards related to flash floods have caused serious damage and losses to the population of the state of Rio de Janeiro. This research discusses the importance of ...implementing a methodology for the prevention of flash floods, by comparing the methods applied since 2013 in the city of Duque de Caxias, in the Baixada Fluminense region of the state of Rio de Janeiro, Brazil, and the major prevention actions suggested by the Flash Flood Early Warning System Reference Guide from the National Oceanic and Atmospheric Administration, questioning civil defense professionals about the importance of each method to vulnerable communities. Even without the occurrence of an extreme event that proves the effectiveness of the method between 2014 and 2016, the population will certainly be better prepared to face the risks of disasters in the city in the future. In addition, the study also underscores an approach of approximation between academic studies and operational activities, which is still very incipient in Brazil.
Sri Lanka has a high incidence of natural hazards with hydrometeorological hazards being the most prevalent. Despite the fact that structural measures such as flood walls and embankments play a vital ...role in disaster mitigation, it is observed that there is a gap in the development of effective, sustainable, and state of the art structural measures in Sri Lanka. This paper, in this context, aims to assess the nature of existing structural measures in the country in order to highlight what improvements are needed, and the costs and benefits of the necessary improvements. This is achieved through a comprehensive literature review followed by the analysis of twelve semi-structured interviews conducted with experts in the subject of structural measures for disaster mitigation. The findings reveal that Sri Lanka has sufficient types of structural measures in relation to floods, landslides, and coastline erosion compared to other developing countries. However, age and outdated technology are critical issues that hinder the expected performance of the measures. Moreover, it is observed that sufficient structural measures for mitigating the risk of drought related disasters are not in place in Sri Lanka compared to measures for other hydrometeorological hazards. The key benefits of improving structural measures in the country are identified as land development, economic growth, and increased stability of cities, and the main costs and challenges are high initial capital cost, high maintenance and repair cost, and the negligible residual value of structural measures. The findings of this study will lead to gaining a comprehensive understanding of gaps and weaknesses in structural measures in Sri Lanka and will influence policymakers and other respective practitioners in disaster mitigation to effectively enhance the existing portfolio of such measures.
•Structural measures alter the features of hydrometeorological hazards and reduce the disaster risk•Sri Lanka has appropriate types of structural measures for floods, landslides, and coastline erosion but not for droughts•Age and the outdated technology of the structural measures in Sri Lanka are major concerns•Achieving the correct balance between the financial costs of structural measures and their benefits is important
On 27 June 2006 the Council of the European Union reached political agreement on a draft directive on the assessment and management of flood risks. This directive prescribes approaches and procedures ...which should be met by the member states. The website of the EU on this directive links to another EU-initiative, the Integrated Project FLOODsite, which aims at providing methodologies for flood risk analysis and management. Obviously, the directive and the IP emerged in a common but much larger context of public and scientific debate on a more integrated and coordinated approach to dealing with flood risks. In this paper we briefly discuss this context and examine a few national cases in order to find out whether flood risk management is already common practice or is still in its infancy, or whether it involves merely good intentions. We base this examination primarily on our experiences within FLOODsite and on presentations held within the special session on River Flood Risk Management which was organised by The Netherlands Centre for River Studies (NCR) during the ISDF3 conference in May 2005. This paper goes into the similarities and differences between some national approaches and tries to place them in a cultural context. It appears that the seemingly most sophisticated management policies do not automatically imply the most comprehensive flood risk management approach. But the intention to evolve from flood management into flood risk management is evident and promising.
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