Global-SHANEL Asia model predicting chemical concentration in rivers with high spatio-temporal resolution, suitable...

Assessing the concentrations of various chemicals in river water is critical for ensuring global environmental sustainability. There is an increasing need to assess water risks in southeast Asia due to the increasing chemical pollution associated with the rapid economic growth and abnormal weather. Although AIST-SHANEL, a model for analyzing chemical concentrations in river water based on the characteristics of individual rivers and meteorological conditions, is useful for assessing the water risks, this model currently only applies to Japanese rivers due to the lack of global data. To facilitate the high-spatio-temporal-resolution exposure assessment for aquatic organisms systems in southeast Asia, we built a Global-SHANEL Asia model (expanded model of the AIST-SHANEL) by collecting and processing open geospatial and meteorological data in Asia. Estimated river flow rates and concentrations of linear alkyl benzenesulfonic acid (LAS) were compared to measured values. Our model precisely estimated the seasonal variation of flow rates related to weather changes and predicted LAS concentrations at a practical level (within one order of magnitude). The model visualizes the overall distribution of LAS concentrations in southeast Asia and identifies hotspots where chemical concentrations could increase. The model visualizes the chemical distribution across countries to facilitate risk assessments for chemical pollution in future climate change and population projections. The model identifies chemical pollution and aids decision-making to promote environmental sustainability.