Application of Multiattribute Analysis (MAA) Methodologies to the Evaluation of the Effectiveness of Remedial Strategies with the MOIRA System

Abstract

The evaluation submodule of the MOIRA system (Ríos-Insua et al., 2000) is based on a multi-attribute additive utility model, aimed at identifying the optimal remedial strategies for restoring aquatic ecosystems contaminated by radionuclides. It includes facilities for assessing imprecise scalar utility functions and weighting factors, as well as a sensitivity analysis tool to check the sensitivity of the conclusions to the inputs, to allow the decision makers to gain insights into the problem. The selection of the optimal strategy should be based on all relevant information, and the end objective is to minimize the impact of contamination, not only from the radiological point of view, but also taking into account other important environmental, social and economic effects that the decision could entail. This chapter describes the application of the MOIRA system to analyse a set of alternative remedial strategies in the case of Lake Kozhanovskoe, located in the Bryansk region in Russia, which resulted heavily contaminated with 137Cs after the Chernobyl accident in 1986. As it has been described in the previous chapter on the application of the dose assessment module, the lake Kozhanovskoe was in 1998 granted the status of radioecological reserve and fishing was officially forbidden because of the high levels of fish contamination with 137Cs. The purpose of the application of MOIRA system to the lake Kozhanovskoe scenario is to test the effectiveness of several alternative countermeasures, by using the MAA methodology contained in the MOIRA evaluation submodule (version 2, Jimenez et al., 2001). Since the chapter focuses on the application of the MAA, methodological descriptions are limited to those aspects necessary for a better understanding of the reasoning behind the analytical process without unnecessary details that can be found elsewhere (RíosInsua et al., 2000, Ríos et al. 2000, Jiménez et al., 2001, Mateos et al., 2001). Emphasis is put on describing the application, capacities and usefulness of the MAA module of MOIRA under realistic test conditions. First of all, a description of the problem scenario is made, followed by the step-by-step analysis of the first set of strategies tested with MOIRA system. Then, searching for an optimum solution, new strategies are introduced, and sensitivity analyses are performed to check the consistency of the final ranking between the alternative strategies.