METEOR: a step-by-step procedure to explore effects of indicator aggregation in multi criteria decision aiding – application to water management in Berlin, Germany

METEOR (METhod of Evaluation by ORder) is introduced as a new evaluation approach, based on partial order theory. METEOR combines transparent decision support and convenient tools for data analysis with the ability to include stakeholders' preferences in the decision process. The basic idea is a systematic step-by-step aggregation of indicators, including their weighting. We applied METEOR to evaluate the eco-hydrological effects of nine water management strategies upon the complex surface water system of Berlin and Potsdam, Germany. Altogether 14 river sections are defined, each of which is evaluated by a set of four hydro-chemical indicators. Aggregation of indicators was performed on two levels: spatially with respect to the river sections, and thematically to the four indicators themselves. The METEOR result is in good agreement with that obtained by the PROMETHEE approach. However, advantages of METEOR are (1) identification of sensitive steps of indicator aggregation, and (2) extraction of explanatory background information about advantages and disadvantages of scenarios. Both topics enhance the transparency of the evaluation process and thus support public acceptance of the decision.