Proposed framework of indicators to monitor global river health.

Each indicator is described with both challenges and opportunities for application to global monitoring, the methods available for implementation by 2030, and recommendations for development toward more accurate and widespread implementation by 2050 [see S1 Table for sources of in situ, remote sensing, and modelled datasets to support development of specific indicators]. Inclusion of each indicator within national or regional and global monitoring programs is shown (● = included, × = not included).