17 - Uncertainty in risk analysis of water resources systems under climate change

Summary

ABSTRACT

A three-phase system framework is identified to assess uncertainty in the risk analysis of water resources systems under climate change. The uncertainty arises among others from the hydrometeorological inputs, such as precipitation and temperature, that are used for predicting extreme events (floods and droughts) under climate change. These inputs play an important role in the three system phases, namely planning, design, and operation. In this study, the hydrometeorological inputs under climate change are obtained by using downscaling models that use information from a general circulation model (GCM) output. The uncertainty is assessed by a new technique using a fuzzy approach. The methodology is illustrated by an example of uncertainty assessment in the risk analysis of a water resources system under climate change in a semi-arid region.

THREE-PHASE SYSTEM FRAMEWORK

A water resources system, such as a reservoir built for flood control or for water supply during severe droughts, may be described in three phases, namely planning, design, and operation. Planning phase of a water resources system must take into account multiple users, multiple purposes, and generally multiple criteria and/or objectives. Furthermore, in the planning phase, the emphasis also needs to be given to the system sustainability. A sustainable system should not only meet the present demands but should also consider future generations' demands. The notion of sustainability which is often described by non-numerical, qualitative, and philosophical means, may be found in more detail, for example, in Haimes (1992), Gleick et al. (1995), Plate (1993), and WCED (1987).