https://doi.org/10.1029/2018GL077914

Allen, G. H., David, C. H., Andreadis, K. M., Hossain, F., & Famiglietti, J. S. (2018). Global estimates of river flow wave travel times and implications for low-latency satellite data. Geophysical Research Letters, 45(15), 7551-7560. https://doi.org/10.1029/2018GL077914

Earth-orbiting satellites provide valuable observations of upstream river conditions worldwide. These observations can be used in real-time applications like early flood warning systems and reservoir operations, provided they are made available to users with sufficient lead time. Yet the temporal requirements for access to satellite-based river data remain uncharacterized for time-sensitive applications. Here we present a global approximation of flow wave travel time to assess the utility of existing and future low-latency/near-real-time satellite products, with an emphasis on the forthcoming SWOT satellite mission. We apply a kinematic wave model to a global hydrography data set and find that global flow waves traveling at their maximum speed take a median travel time of 6, 4, and 3 days to reach their basin terminus, the next downstream city, and the next downstream dam, respectively. Our findings suggest that a recently proposed ≤2-day data latency for a low-latency SWOT product is potentially useful for real-time river applications.

https://doi.org/10.1029/2018GL077914