The Need for a Multi-Pollutant Approach to Model the Movement of Pollutants in Surface-Water: A Review of Status and Future Challenges

Abstract

Significant research on surface water pollution modelling has been carried out over diverse landscapes has sought to explain the sources, transport, and surface water pollution. To date, surface water pollution studies have focused on nutrients, plastics, and chemicals. Consequently, the current review aims to identify and synthesise peer-reviewed literature about integrated contaminants modelling in surface water. Thus, highlighting that modelling potentially multiple sources of a pollutant from the surface water has remained a thought-provoking topic. Studies differed significantly in terms of the type of model application and procedures for reporting findings, making it challenging to separate clear trends and patterns. Accordingly, most studies agree that pollutants such as plastics and agrochemicals can have adverse consequences on surface water quality; these coincide with difficulties in modelling pollutant transport. Consequently, no regional or global estimates are available for the water pollution burden of flood-related pollution, considering the demonstrable modelling techniques, the significance of the concurrent impacts of surface water pollution by contaminants. Multi-pollutant approaches to modelling the potential sources of pollution and encourage protective behaviour are essential. Mainstreaming freshwater pollution concerns into planning strategies will also be needed to lessen anthropological contribution to surface water pollution. While the implementation of these models is constrained by lack of adequate field data, the model output must be analysed within the model inputs' uncertainty, data limitations and methodologically established surface water modelling principles from the literature.