Integrated ecological modelling for decision support and risk assessment in river water quality management

Abstract

Modelling is an effective tool to investigate or to predict the ecological state of water resources and the response to natural driving variables or anthropogenic pressures. Model integration is required to perform comprehensive evaluations which would be impossible when analysing each individual component of the system separately. Current practice in model integration does not consider the simultaneous effect of hydromorphological disturbances and physicochemical pollution on the river ecology. Therefore, the aim of this study was to develop and to evaluate an integrated ecological modelling framework for decision support and risk assessment in river management. This framework is called the Integrated Ecological Modelling Framework (IEMF). The IEMF has four basic modelling components: (1) a model characterising the processes of wastewater treatment plants; (2) a river water quantity model; (3) a physicochemical river water quality model and; (4) a river ecological model. The IEMF was tested and validated in three case studies considering rivers in Colombia, Ecuador and Croatia. The IEMF assists the water quality managers (authorities): (1) by calculating the effect of future investments in sanitation infrastructures and river restoration actions on aquatic ecosystems and by supporting the selection of the most sustainable options; (2) by predicting and assessing the achievement of predefined ecological water quality objectives