Multi-Criteria analysis (MCA) is a tool that has been developed for analysing complex multi-criteria problems. It is a thoughtful methodology that takes into account both qualitative and quantitative aspects of the problems so as to facilitate the decision making process. In multi-criteria analysis, desirable objectives are specified and corresponding indicators are identified. Different environmental and social indicators can be developed alongside with economic indicators.
It is commonly admitted that using the framework of multi-criteria analysis entails crucial methodological issues. These issues are often time-consuming and deal with (i) selection of criteria, (ii) weights of criteria, (iii) decision rules and (iv) selection of participants among stakeholders for participating in the decision making process.

In THESEUS, an integrated risk assessment approach is performed for providing coastal managers with an holistic assessment to support them in their decision making. Hydraulic, environmental, social and economic dimensions are integrated into a multi-criteria analysis. Multi-criteria analysis is carried out at both stages of the risk management process, i.e. through:

  • multi-criteria risk assessment (MRA), where risk magnitude and spatial distribution are identified, and
  • multi-criteria project appraisal (MPA), where mitigation measures are assessed with regard to direct costs, monetary benefits (i.e. damages avoided) and non-monetary benefits (i.e. reduction of environmental or social risk as evaluation criteria).

It is assumed that some uncertainties in flood risk analysis occur. For example, these uncertainties can deal with:

  • the probability of flood events: errors may arise from the extrapolation of short time series flood discharges; or
  • the depth and the area of inundation: imprecisions may come from generalised digital terrain models or from difficulties in estimating failure probabilities of flood coastal defences;

As a result, the decision matrix or the criterion maps which form the basis for multi-criteria analysis contain uncertainties. Within the project, these uncertainties are documented by a range (i.e. a lower and upper value as a mean value) for instance.

In LUPIS, multi-criteria analysis has been used in the third step of the assessment process: i.e. the post-modelling phase. In this phase, the ensemble of results, which have been previously determined from computer-based models in the second phase, became accessible for comparing indicators related to Land Use Functions (LUFs) towards various scenarios (established in the first phase).
As a result, the impact of various policy options with regard to sustainable development has been achieved. An application case in China, among a total of seven case studies in different developing countries, has been detailed using this three-phase methodological framework.

Coastal flood protection: What perspective in a changing climate? The THESEUS approach. Environmental science & policy 14 (2011) 845 - 863
Methods and tools for integrated assessment of Land use policies on sustainable development in developing countries. Land Use Policy 28 (2011) 604-617.