Assessment of impact of climate change on water resources: a long term analysis of the Great Lakes of North America

摘要

In the threshold of the appearance of global warming from theory to reality,extensive research has focused on predicting the impact of potential climatechange on water resources using results from Global Circulation Models(GCMs). This research carries this further by statistical analyses of longterm meteorological and hydrological data. Seventy years of historicaltrends in precipitation, temperature, and streamflows in the Great Lakes ofNorth America are developed using long term regression analyses andMann-Kendall statistics. The results generated by the two statisticalprocedures are in agreement and demonstrate that many of these variables areexperiencing statistically significant increases over a seven-decade period.The trend lines of streamflows in the three rivers of St. Clair, Niagara andSt. Lawrence, and precipitation levels over four of the five Great Lakes,show statistically significant increases in flows and precipitation.Further, precipitation rates as predicted using fitted regression lines arecompared with scenarios from GCMs and demonstrate similar forecastpredictions for Lake Superior. Trend projections from historical data arehigher than GCM predictions for Lakes Michigan/Huron. Significantvariability in predictions, as developed from alternative GCMs, is noted.Given the general agreement as derived from very different procedures,predictions extrapolated from historical trends and from GCMs, there isevidence that hydrologic changes particularly for the precipitation in theGreat Lakes Basin may be demonstrating influences arising from globalwarming and climate change.