The future of Chinese rivers: Increasing plastics, nutrients and Cryptosporidium pollution in half of the basins

Abstract

Many Chinese rivers are polluted with multiple pollutants. Therefore, this study aims to quantify the annual inputs of nutrients, macro-and microplastics, and Cryptosporidium (a pathogen) to 395 Chinese rivers from agriculture and urbanization-related sources during 2010–2050 following the storyline of Shared Socio-economic Pathway 3 and Representative Concentration Pathway 8.5. Our model estimates that multiple pollutants in Chinese rivers are projected to increase by 41–88 % between 2010 and 2050. Central, eastern, and southern Chinese sub-basins may be more polluted in the future. In half of the sub-basins, at least two types of pollutants are expected to increase by over 50 % during 2010–2050. By 2050, nutrients and plastics in rivers are projected to increase by 70 % due to urbanization. For nutrients and Cryptosporidium in rivers increases of 49–88 % are projected, due to agricultural activities. In contrast, water is expected to get cleaner in some western sub-basins by 2050 because of fewer human activities. Our insights about multiple pollutants in Chinese rivers could help prioritize water pollution reduction strategies for sub-basins.