Quantitative micro-scale flood risk assessment in a section of the Trotuș River,Romania

This paper focuses on the estimation of direct damages caused by three flood scenarios with different return periods in the section Făgetul de Sus – Ghimeş – Palanca Pass of Trotuș River, with the aim of highlighting the need of improved land use plans. The damage for three land use classes (residential building, infrastructure and agriculture) were estimated using the damage curves developed by the European Joint Research Centre (JRC) as well as site specific maximum damage values. The data were processed with the help of the ArcMap 10.2 software and FloodRisk tool from QGIS software. Furthermore, the flood risk was assessed using the damage – probability curves, which associates the damage with the corresponding frequency of occurrence. This method was identified and adapted to the characteristics of the study area in order to develop a methodology of flood risk assessment that is answering the question: does the lack of land use plans increase the vulnerability and the flood damage? The results showed that the greatest damages are registered for the residential building land use class for a flood probability of 0.001. In this case the damages reach up to 60% on the scale range of deterioration factor, the total damage value being 2 million euros. For the same hazard probability the total registered damage value for roads is 7500 euro, for railways is around 12,000 euro, while for agriculture is around 84,000 euro. These results highlight the need of protection measures and land use plans development and implementation. Regarding the protection measures we consider that the egalitarianism would be the concept that should be applied in the study area and also an improved cooperation between government, specialized agencies and local authorities at local level would lead to a more efficient flood risk management process. The proposed methodology can be applied for micro-scale analysis, providing quantitative results regarding the flood damage and flood risk assessment. It includes a detailed vulnerability analysis of the elements-at-risk with the aim of developing a more comprehensive approach of flood risk assessment.     

Switzerland’s transition from flood defence to flood-adapted land use–A policy coordination perspective

This contribution examines Switzerland’s shift towards integrated flood risk management from a policy coordination perspective. The study applies a heuristic framework of policy coordination to explore how adaption needs promoted cross-sectoral policy coordination between hydraulic engineering and land use planning and enhanced coherence in flood policies targeting extreme flood events. To account for the temporal dimension in policy coordination, the article traces Swiss flood policies back to the early 1800s and distinguishes four phases of policy coordination. Across the four periods, the analysis focuses on (a) the drivers of policy coordination, (b) the manifestation of policy coordination in terms of policy frames, goals, instruments and subsystem involvement, and (c) the performance of policy coordination. Complemented by an in-depth case study of cross-sectoral flood policies in the Swiss canton Nidwalden findings show that the coordination between flood and land use policies has primarily been driven by three factors: (i) extreme floods as focusing events, (ii) an increasing problem pressure, and (iii) strategic reorientations in flood and land use policies. Today, flood risk management in Switzerland displays a high degree of sectoral interplay between hydraulic engineering and spatial planning. By fostering flood-adapted land uses Switzerland’s coordinated flood policies reduce the vulnerability to uncertain future changes in flood risk and strengthen the country’s capacities to mitigate damage in extreme floods events.     

The decision game: a serious game approach to understanding environmental risk management decisions

Abstract

Here we describe the implementation of an experimental research tool called the Decision Game that we used to collect data on household flood risk management decisions. Participants using this tool play an interactive game that involves making household decisions about place of residence and a variety of household expenditures, including spending on flood insurance and private flood risk mitigation. Participants also answer survey questions before and after playing the game; the pre-game survey collected demographic information, and the post-game survey collected information about participant experiences with flooding and flood mitigation. Online and face-to-face participants showed similar engagement with the experiment, and most participants appeared to have made deliberate and considered decisions about risk mitigation. Online study participants had similar responses to those who participated in person, although face-to-face participants seemed slightly more likely to mitigate against risk. Overall, participants in this research were younger, more educated and more likely to rent a home than the average Canadian. Serious games may be useful for augmenting existing data gathering strategies used in understanding environmental decision making, particularly for rare catastrophic events for which stated preference surveys may be less informative. Serious games allow for sharing a mixture of information with study participants, including maps, video clips, text and even immersive 3D experiences, and can be administered online to increase participation levels. Future research will consider longer duration online experiments and more immersive interaction frameworks.     

Impacts of land-cover change on the water flow regulation ecosystem service: Invasive alien plants,fire and their policy implications

Land and water resource issues typically fall under separate governance systems. For example, agricultural policy regulates land-cover change while water departments regulate water quality. However, land-use changes can directly affect water resources. Water flow regulation is a key service which is affected by changes in land-cover but its dynamics are poorly understood by most policy makers and land management organisations. We simulated and quantified the effects of plant invasions on land-cover, hydrological soil characteristics and catchment responsiveness on flow regulation using a hydrological model. The case study was located in the indigenous fynbos shrublands in South Africa. Fynbos requires fire to regenerate, has moderate biomass, occurs mostly in areas with a potential to erode and is prone to invasion by woody plant species, particularly trees. Invasions can affect flow regulation by changing community structure and function and increasing fuel loads. The greater fuel load increases fire intensity and severity which, in turn, changes the hydrological responses of catchments. Few studies have assessed the effects of invasion on hydrological responses but studies on plantations have recorded significant increases in soil water repellence following fire, resulting in increased overland flow similar to impacts of fires in invaded areas. Simulation of clear-felling of pines and different degrees of water repellency increased both the responsiveness of the catchment to rainfall and extreme rainfall events. The simulated fire effects were consistent with other studies of hydrological responses to fire. Our study indicates that invasions of pines and acacias in the study area could substantially increase the risk of flood damage even from moderate rainfall events, and highlights the importance of maintaining flow regulation capacity. New policy approaches are required which take account of the linkages and interactions between land-use choices, water resources and ecosystem services, and address them when considering governance arrangements.     

Moving out or living on a mound? Jointly planning a Dutch flood adaptation project

All over the world spatial flood risk management policies are on the rise. This paper analyses the planning process for the Overdiepse polder, a so-called “Room for the River” project in the Netherlands. After high water in the 1990s, the Dutch government changed its flood risk management policy. While before 2000 it leaned heavily on dikes to separate water from land, after that year spatial measures to “let the water flow” were introduced. This required the integration of two formerly separated policy domains: flood risk management and land use planning. In the densely populated and economically highly developed Netherlands, returning space to the river unavoidably impacts on the lives and livelihoods of those who live and work along the rivers. Therefore, such spatial measures to decrease flood risk have to be negotiated with various stakeholders. The planning process towards making the Overdiepse polder suitable for temporary water storage deserves more in-depth analysis. We describe and analyze the development of relationships between key actors in the planning process, with a focus on planning practices rather than on assumptions about the existence of certain types and qualities of relationships. We conclude, among others, that citizen involvement can, under specific socio-political and institutional conditions, build trust among stakeholders and increase local legitimacy for interventions by government agencies. However, it should not be idealized as “self-governance” or assumed to be part of a unidirectional change in water interventions towards new relationships between actors.     

The impact of flood dynamics on property values

There is evidence that environmental amenities and dis-amenities may be nonlinearly related to property valuation. This would bring inconsistency in estimating environmental variables of the hedonic price model. To explore the linearity of the relationship this study analyses spatial and temporal variation impacts of the 2011 Brisbane flood on property markets using semi-parametric estimation. The results show that most environmental variables impacts on property values nonlinearly, and in particularly distance to the river, indicating that the amenity value of being close to a river outweighs the flood risks. The estimation of the combined impact of elapsed time and neighbourhood income indicates that the flood risk impact on property markets disappears over time.     

Quantifying land-use change impacts on the dynamic evolution of flood vulnerability

Recently, dramatic flood disasters have occurred incrementally in several regions of the world. Land-use change as one of the main affecting factors becomes a key component in flood risk management. This study strives to deal with quantifying how changes in land use to affect the dynamic evolution of flood vulnerability. The floodplains of Wuhan, which are located in the Yangtze River Basin, have been selected as an example. In this paper, we use GIS to gather different historical geometric data as sources of land-use information. By proposing the Simpsons-dominance index and location index to analyze the characteristics of land-use changes, and building a quantitative model to measure flood vulnerability, a series of flood vulnerability maps demonstrate differential flood vulnerability of floodplains of Wuhan in three inundation scenarios and four historical periods. Finally, the non-parametric correlation is used to reveal the interactive effect of land use and flood vulnerability. Based on this study, comprehensive flood disaster management strategies for land-use planning are proposed for government decision-makers to reduce the flood vulnerability of Wuhan in future.     

Discourse and practice of participatory flood risk management in Belfast,UK

The introduction of the Floods Directive signals a move from flood protection towards flood risk management in the European Union. Public participation is highlighted in the Floods Directive as being instrumental to effective implementation of this new approach. This study utilised document analysis, non-participant observation, a questionnaire survey, and interviews to evaluate the discourse and practice of participation in the implementation of the Floods Directive in Belfast, United Kingdom. Flood risk management processes in Belfast are found to be high on participatory rhetoric but low on meaningful engagement. The participatory process is lacking in transparency, does not encourage the active participation of interested parties and has not been clearly communicated to key publics. Opportunities to increase meaningful public participation in the process remain underutilised, and the establishment of local flood forums has provided little opportunity for meaningful engagement. Some actions of governance agencies could be best characterised as facilitating the responsibilisation of risk and are designed to manage risk to agencies rather than address flooding issues.     

The role of public participation in encouraging changes in rural land use to reduce flood risk

Changes in rural land use to reduce flood risk are encouraged by governments in many countries, but they may face considerable opposition by land managers. Local participative processes are thought to help overcome opposition. This article presents an evaluation of an intensive participative process set up between land managers and governmental agencies following two severe floods in the transboundary Bowmont–Glen catchment in Scotland and England. A combination of interviews and documentary analysis is used. The research demonstrates that the participative process contributed to greater uptake of rural land use change and improved compliance with existing environmental policies. There were nevertheless low levels of social learning amongst participants. Two institutional designs for improving policy implementation are presented.     

A game of give and take: The introduction of multi-layer (water) safety in the Netherlands and Flanders

At the beginning of the 21st century, the Netherlands and Flanders introduced a risk-based approach to flood risk management (FRM), labelled as multi-layer (water) safety. In contrast to a flood defence approach, risk-based management stresses the need to manage both the consequences and probability of a flood. The concept has developed differently in the two countries, as we conclude from a discursive-institutionalist research perspective. The Netherlands is characterised by a high institutionalization of the traditional flood defence discourse and a more closed policy arrangement, whereas in Flanders, the flood defence discourse is less institutionalized and the arrangement is more open. In both countries we see an opening of the arrangement preceding the establishment of multi-layer (water) safety, but at the same time, actors stress different aspects of the concept in order to increase its compatibility with the existing policy arrangement. In the Netherlands, the focus is on probability management, in Flanders on consequence management. In the Netherlands, multi-layer (water) safety as a concept could be established because it stabilises the system in the short-term by reinforcing the importance of flood defence, whereas in Flanders, policymakers were receptive to the concept because it supports a shift of responsibility towards actors outside traditional water management.