Global multi-pollutant modelling of water quality: scientific challenges and future directions

TLDR

Assessing global water quality requires a multi‑pollutant modelling approach that integrates information on pollutant sources, effects, and solutions. The paper explains multi‑pollutant modelling, discusses its scientific challenges and future directions, and considers how model results can inform policy. The authors discuss challenges in consistent inputs, modelling approaches, and evaluation, and illustrate the potential of global multi‑pollutant modelling for hotspot analyses. They identify hotspots of river pollution with microplastics, nutrients, triclosan, and Cryptosporidium across many sub‑basins in Europe, North America, and South Asia.

Abstract

Assessing global water quality issues required a multi-pollutant modelling approach. We discuss scientific challenges and future directions for such modeling. Multi-pollutant river models need to integrate information on sources of pollutants such as plastic debris, nutrients, chemicals, pathogens, their effects and possible solutions. In this paper, we first explain what we consider multi-pollutant modelling. Second, we discuss scientific challenges in multi-pollutant modelling relating to consistent model inputs, modelling approaches and model evaluation. Next, we illustrate the potential of global multi-pollutant modelling for hotspot analyses. We show hotspots of river pollution with microplastics, nutrients, triclosan and Cryptosporidium in many sub-basins of Europe, North America and South Asia. Finally, we reflect on future directions for multi-pollutant modelling, and for linking model results to policy-making.