Totaling river discharge of the third pole from satellite imagery

The high-mountain Third Pole (TP) in Asia is undergoing rapid warming, profoundly impacting river discharge. Changes in precipitation and the degradation of glaciers and permafrost exert a substantial impact on TP rivers, affecting millions downstream. Nevertheless, conventional estimation methods that rely on in-situ observations and models face considerable challenges due to inconsistent data quality and availability, complex terrain, and difficulty in representing hydrological processes. Here, we harnessed the power of high-resolution (3 m) Dove/PlanetScope satellite images to meticulously measure river width and propose a novel formula for estimating discharge. This approach facilitates a coherent assessment of discharge at various river section shapes. Its efficacy is demonstrated through applying to thirteen high-mountain TP rivers, revealing an estimated total mountain discharge of 3786 billion m3 during 2017–2021, equaling water from approximately 167 Great Lakes. These findings have immediate implications for integrated water resources management at the poorly-gauged transboundary basins of Asia.