Tuesday, 15 January 2002: 11:45 AM
Hydro-climatic factors and socioeconomic impacts of the recent record drop in Laurentian Great Lakes water levels
Between 1998 and 2000 the levels of Lakes Michigan-Huron set a record two year decline. This decline was notable for both the extent and rapidity of occurred. This spring the levels of Lakes Michigan-Huron were the lowest since 1965 and Lake Superior levels were the lowest since 1926. The episode started with the 1997-98 El Nino which resulted in very low snow cover in the upper parts of the Great Lakes basin. This condition was exacerbated by extremely warm air temperatures which greatly reduced runoff and increased evaporation from the lake surface. The situation has been ameliorated somewhat by adequate precipitation and snowfall during the winter and spring of 2001. However, Lake Michigan-Huron is still near its long-term record low in July. The drop in levels has adversely impacted commercial navigation, recreational boating, and hydro-power. The decreased levels have resulted in the best beaches in the last 35 years. This paper discusses in detail the hydro-climatic factors behind the rapid drop in water supplies and compares this episode with severe conditions in the mid-1960s and 1930s.