卫星揭示全球河流已被人类改变

SWOT is exposing how humans reshape rivers—and challenging models used to predict floods PAUL VOOSEN “The river is a river, not a line,” sang folk singer Patty Griffin. After nearly 4 years in orbit, a radar satellite launched by NASA and CNES, the French space agency, is revealing the truth of the lyric. By simultaneously measuring the water levels and breadth of rivers around the world, the Surface Water and Ocean Topography (SWOT) satellite is exposing the true complexity of those blue lines on a map. They are dammed, braided, frozen, or drained—with behaviors that hydrologic models struggle to capture, says Colin Gleason, a hydrologist at the University of Massachusetts Amherst. …