Popis: |
Summary It has been proposed that global warming will amplify the water cycle and intensify river floods. We tested this hypothesis by investigating historic trends in magnitudes, durations and timing of the annual peak flows of rivers that drain the Rocky Mountains around the North American hydrographic apex, the source for rivers flowing to the Pacific, Arctic (including Hudson Bay) and Atlantic Oceans. We sought century-long records and to reduce influences from land-use we assessed drainages from parks and protected areas. Of 30 rivers and reaches that were free-flowing or slightly regulated, seven displayed declining peak flows (7 p |