Extending global river gauge records using satellite observations

Long-term, continuous, and real-time streamflow records are essential for understanding and managing freshwater resources. However, we find that 37% of publicly available global gauge records (N = 45 837) are discontinuous and 77% of gauge records do not contain real-time data. Historical periods of social upheaval are associated with declines in gauge data availability. Using river width observations from Landsat and Sentinel-2 satellites, we fill in missing records at 2168 gauge locations worldwide with more than 275 000 daily discharge estimates. This task is accomplished with a river width-based rating curve technique that optimizes measurement location and rating function (median relative bias = 1.4%, median Kling-Gupta efficiency = 0.46). The rating curves presented here can be used to generate near real-time discharge measurements as new satellite images are acquired, improving our capabilities for monitoring and managing river resources.

Automated summary

Long-term, continuous, and real-time streamflow records are crucial for understanding and managing freshwater resources. However, a significant portion of global gauge records are discontinuous and lack real-time data. To fill in the gaps, river width observations from satellite imagery have been used to estimate daily discharge at over 2000 gauge locations worldwide. This method improves our ability to monitor and manage river resources.