Sustainable Water: Uncertainty, Risk and Vulnerability in Europe

A project funded by the EU Energy, Environment and Sustainable Development Programme Supported by the Swiss Office of Higher Education

Problems to be solved

Many attempts have been made to assess the impacts of climate change and variability on crucial hydrologic and hydraulic systems such as those used for flood protection, water supply or urban drainage. Such systems can be extremely vulnerable to predicted climate changes, but two major problems have affected the assessment of their vulnerability, and planning of mitigation or avoidance:

Great uncertainty is inherent in future climate scenarios. This arises from a number of sources, including prediction of greenhouse gas emissions, imperfect climate models, and incomplete understanding of how global climate sensitivity relates to regional and local climates. Dealing with this uncertainty requires consideration of the whole range of possible scenarios rather than a 'best guess' or arbitrarily selected set of scenarios.

The risk of failure of various systems, and subsequent vulnerability, is difficult to quantify, as it may depend on the occurrence of extreme events, either singly, in sequence or in combination with other events. Since extreme events occur infrequently, they are difficult to characterise. Quantifying this risk therefore also calls for a probabilistic framework using large ranges or long time series of hydro-meteorological scenarios and possible consequences, demanding the development of novel statistical methodologies.

Scientific objectives and approach

SWURVE proposes a two-fold strategy for solving these problems in the context of designing and planning for sustainable water and associated activities in Europe:

1. Development of a probabilistic framework for the treatment of future scenarios and their impacts resulting in assigning probabilities of various critical outcomes and risks, rather than single central estimates;
2. Development of a quantitative and transferable methodology for the measurement of long term sustainability using statistical measures such as reliability, resilience and vulnerability.

A range of representative and different case studies will be used to develop and validate these methodologies. The hydrologic systems to be investigated and assessed include conventional water resource systems, but also related and dependent systems which require further analysis. The studies will define GCM scenarios, rainfall downscaling methods, statistical methods and so on, and allow comparison of results.

Expected impacts

Improved and transferable methods of measuring performance of hydrologic and hydraulic systems, and impacts under climate change to allow planning and design for a sustainable future.

Methods will be available to address the problems of incorporating uncertainty into impact assessments, using a probabilistic framework to combine different sources of uncertainty and error. The methods will take full account of natural climate variability, uncertainty in climate predictions and uncertainty in future demand.