A Tool for Evaluating Risk to Surface Water Quality Status

Water quality Risk Analysis Tool (WaterRAT) is recently developed software for supporting surface water quality management. The software contains a library of river and lake quality models, aiming to give flexibility over specification of model scope, complexity and scale. Various sources of uncertainty can be included in the analysis, including uncertainty in boundary conditions, initial conditions, parameters, model structure and management objectives. Water quality can then be modelled allowing for these sources of uncertainty. Important data uncertainties can be indicated, and so data collection programmes can be suitably refined. In this paper, the motivation for the WaterRAT tool and the methods it employs are presented, its features are described, and its utility for uncertainty evaluation and sensitivity analysis is demonstrated using a river water quality management problem. Emerging challenges for modellers, which cannot yet be addressed using WaterRAT, are discussed.