Publication Date
12-5-2003
Abstract
Hydrology is embedded in climate. The water potentially available for human use and management, Q, is determined as the difference between long-term average precipitation, P, and evapotranspiration, E: Q = P_E. 23 = 41_18 inches/yr (New England averages). P is obviously a central component of climate, and E is largely determined by climatic factors, especially temperature, humidity, wind, and the timing of precipitation inputs. The presentation will include a review of recent literature leading to an assessment of predicted and observed changes in aspects of New England hydroclimate as a result of projected global climate change. New England has experienced severe droughts approximately once per decade since the late 1800s, the most severe and extensive of which was the drought of the 1960s. This drought and monthly and winter streamflows generally are correlated with the North Atlantic Oscillation (NAO), especially at decadal scales; but there is no correlation between NAO and precipitation. Winter streamflows are correlated with the Pacific North American pattern (PNA). There is no consistent correlation of New England hydroclimate and the El Nino-Southern Oscillation phenomenon. Human population growth in New England has been accompanied by activities that have strong effects on the region’s hydrology, including landcover changes (afforestation-deforestation, urbanization), inter-basin transfers of water (especially the Boston system), construction of dams, and withdrawals from surface and ground water. In general, these non-climatic factors are more profound and predictable than those that may accompany anthropogenically-induced climate change, at least in the short- to medium-term. Support of government programs that monitor hydroclimate, especially those of NOAA and the U.S. Geological Survey, is essential for understanding and responding to non-climatic and climatic changes that affect the region’s water resources.