Uncertainty analysis in integrated catchment modelling

Abstract

The adoption of increasingly restrictive water quality standards is directed to maintain natural ecosystems in a good status. Complying with such standards requires significant investments in water infrastructure and operations. Consequently, mathematical simulation is usually applied to assist in the decision-making process for such large-scale actuations. In particular, environmental models are proposed to represent the wastewater cycle in natural water bodies, such that the effect of different pollution mitigation alternatives can be estimated. Integrated catchment models (ICM) aim at simulating water quality dynamics by representing the link between urban drainage networks, wastewater treatment operations, rural hydrology and river physical-biochemical processes. However, these subsystems present dynamics acrossmultiple spatiotemporal scales and many relevant processes are still not fully understood. System observations are scarce and often insufficient to identify most model representations. As a result, ICM studies often produce significant output uncertainties.