Streamflow responses to past and projected future changes in climate at the Hubbard Brook Experimental Forest, New Hampshire, United States

摘要: [1] Climate change has the potential to alter streamflow regimes, having ecological, economic, and societal implications. In northeastern United States, it is unclear how climate may affect surface water supply, which of critical importance in this densely populated region. The objective study was evaluate impact on timing quantity at small watersheds Hubbard Brook Experimental Forest New Hampshire. site ideal for analysis because availability long-term hydroclimatological records analyzing past trends ample data parameterize test hydrological models used predict future trends. study, projections were developed with forest watershed model PnETBGC, driven by scenarios from statistically downscaled outputs atmospheric-ocean general circulation models. Results indicated that earlier snowmelt diminishing snowpack advancing reducing magnitude peak discharge associated snowmelt. Past increases precipitation have caused annual yield increase significantly, a trend expected continue under change. Significant declines evapotranspiration been observed over record, although cause not identified. future, response warmer wetter environment. These largely offset precipitation, resulting relatively little streamflow. Future work should aim decrease uncertainty projections, particularly obtain better understanding effect CO2 vegetation, determine if climate-induced changes tree species composition will influence discharge, assess impacts changing hydrology downstream supplies.