气候变暖下的河流动态

Rivers in high Himalayan mountain regions are evolving rapidly because of climate change Shawn M. Chartrand1 and Jonas A. Eschenfelder1,2 Surface sediments in polar and high mountain regions underlain by permafrost—ground that is frozen for two consecutive years or longer—undergo seasonal freezing and thawing. This yearly cycle influences river dynamics by changing water flow and susceptibility to erosion. Consequently, a warming climate can change river configurations in cold landscapes. However, elucidating a causal link between atmospheric temperature trends and river erosion is more difficult than it appears (1). Despite previous efforts (2–5), there is no generally accepted theory describing river erosion in permafrost-dominated basins, in part because of a lack of long-term observations (6, 7). …