Energy, Resources and the Environment

Are you READY for a flood event?

Suzanne Hangx August 14, 2015

As evidenced by the EU Floods Directive (2007/60/EC), flood management strategies in Europe have undergone a shift in focus in recent years. The goal of flood prevention using structural measures has been replaced by an emphasis on the management of flood risks using non-structural measures. One implication of this is that public authorities alone not only take responsibility for flood management. A broader range of stakeholders, who may personally experience the negative effects of flooding, also take on responsibility for protecting themselves. Therefore, it is vital that information concerning flood risks is conveyed to those who may be affected in order to facilitate the self-protection of citizens. Experience shows that problems persist even where efforts have been made to communicate flood risks.

There is a need for the development of new tools that are able to rapidly disseminate flood-risk information to the general public. To be useful these tools must be able to present information relevant to the location of the user. Moreover, the content and design of the tool need to be adjusted to laypeople’s needs. Dissemination and communication influence both people’s access to and understanding of natural risk information. Such a tool could be a useful aid to effective management of flood risks.

To address this gap, a web-based geographical information system (WebGIS) has been developed through the collaborative efforts of a group of scientists, hazard and risk analysts and managers, GIS analysts, system developers and communication designers.

This tool, called “READY: Risk, Extreme Events, Adaptation, Defend Yourself”, aims to enhance the general public knowledge of flood risk, making citizens more capable of responding appropriately during a flood event. The READY WebGIS has allowed for the visualization and easy querying of a complex hazard and risk database thanks to a high degree of interactivity and easily read maps. In this way, READY has enabled fast exploration of alternative flood scenarios or past calamitous events. Combined also with a system of graphic symbols designed ad hoc for communication of self-protection behaviours, it is believed READY could lead to an increase in citizen participation, informed discussion and consensus building.

The platform has been developed for a site-specific application: the Basilicata region, Italy, has been selected as pilot application area. The goal of the prototype is to raise citizen awareness of flood risks and to build social capacity and enhanced resilience to flood events.

Read the whole paper here: Albano, R., Sole, A., and Adamowski, J.: READY: a web-based geographical information system for enhanced flood resilience through raising awareness in citizens, Nat. Hazards Earth Syst. Sci., 15, 1645-1658, doi:10.5194/nhess-15-1645-2015, 2015.

Example of the recommendations, provided by the READY platform, for behavioural actions in case of alert, intended for selfprotection enhancement.

Can climate data help to better predict floods?

Suzanne Hangx August 13, 2015

Flood at Trans-en-Provence (Var - France).
Credit: Dimitri Defrance (distributed via imaggeo.egu.eu)

Many studies report that hydrologic regimes are modulated by large-scale modes of climate variability such as the El Niño Southern Oscillation (ENSO) or the North Atlantic Oscillation (NAO). Climate-informed frequency analysis models have therefore been proposed to condition the distribution of hydrologic variables on climate indices. However, standard climate indices may be poor predictors in some regions. Instead of trying to describe climatic cycles using a single parameter, Renard and Lall developed a model using a range of parameters.

You can read the whole paper here: Renard, B., and U. Lall (2014), Regional frequency analysis conditioned on large-scale atmospheric or oceanic fields, Water Resour. Res., 50, 9536–9554, doi:10.1002/2014WR016277.

Words on Wednesday: River flood risk in Jakarta under scenarios of future change

Suzanne Hangx August 12, 2015

Words on Wednesday aims at promoting interesting/fun/exciting publications on topics related to Energy, Resources and the Environment. If you would like to be featured on WoW, please send us a link of the paper, or your own post, at ERE.Matters@gmail.com.

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Budiyono, Y., Aerts, J. C. J. H., Tollenaar, D., and Ward, P.: River flood risk in Jakarta under scenarios of future change, Nat. Hazards Earth Syst. Sci. Discuss., 3, 4435-4478, doi:10.5194/nhessd-3-4435-2015, 2015.

Abstract:

Given the increasing impacts of flooding in Jakarta, methods for assessing current and future flood risk are required. In this paper, we use the Damagescanner-Jakarta risk model to project changes in future river flood risk under scenarios of climate change, land subsidence, and land use change. We estimate current flood risk at USD 143 million p.a. Combining all future scenarios, we simulate a median increase in risk of +263 % by 2030. The single driver with the largest contribution to that increase is land subsidence (+173 %). We simulated the impacts of climate change by combining two scenario of sea level rise with simulations of changes in 1 day extreme precipitation totals from 5 Global Climate Models (GCMs) forced by 4 Representative Concentration Pathways (RCPs). The results are highly uncertain; the median change in risk due to climate change alone by 2030 is a decrease by −4 %, but we simulate an increase in risk under 21 of the 40 GCM-RCP-sea level rise combinations. Hence, we developed probabilistic risk scenarios to account for this uncertainty. Finally, we discuss the relevance of the results for flood risk management in Jakarta.

Spatial distribution of projected total land subsidence over the period 2012–2025.

Row, Row, Row Your Boat: Predicting Flood Impact with Aqueduct Global Flood Analyzer

Suzanne Hangx August 11, 2015

Mekong river flooded in Cambodia, October 2011.
Credit: Anna Lourantou (distributed via imaggeo.egu.eu)

The Aqueduct Global Flood Analyzer of the World Research Insitute is a web-based interactive platform which measures river flood impacts by urban damage, affected GDP, and affected population at the country, state, and river basin scale across the globe. It aims to raise the awareness about flood risks and climate change impacts by providing open access to global flood risk data free of charge.

The Analyzer enables users to estimate current flood risk for a specific geographic unit, taking into account existing local flood protection levels. It also allows users to project future flood risk with three climate and socio-economic change scenarios. These estimates can help decision makers quantify and monetize flood damage in cost-benefit analyses when evaluating and financing risk mitigation and climate adaptation projects.

In short, the results of the Analyzer are meant to provide a first impression of the distribution of risk among countries, provinces, and basins. This provides an indication of risk magnitude, and an impression of the magnitude of future change in risk that can be expected. The results should be used to focus attention on particular vulnerable areas and open dialogues on the risks and how they can be managed. The results can certainly not be used for the dimensioning of specific flood protection measures. This would require more detailed and locally calibrated models that include additional information on local conditions, including more accurate river profiles, structures, existing flood protection, reservoir conditions and management during floods, and more accurate information on exposure and vulnerability. It would also require thorough engagement with local experts and stakeholders.

The Aqueduct Global Flood Analyzer was developed in collaboration with Deltares, Utrecht University, the Institute for Environmental Studies of the Free University of Amsterdam and the Netherlands Environmental Assessment Agency.