Long-Term Water Level Changes in Closed-Basin Lakes of the Canadian Prairies

Abstract

The semi-arid prairie region of Canada has many closed-basin lakes that are sensitive to climatic variability and change. Long-term water level changes in these lakes provide a measure of the dynamic balance between runoff and precipitation supplying water to the lakes and water loss from the lakes by evaporation. Historic lake water level data can help to improve understanding and prediction of the hydrologic effects of climate change and land-use changes. Water level data for sixteen closed-basin lakes in the Canadian prairies were compiled from a variety of sources and additional measurements were made at some locations. In the Canadian prairie region there is an overall pattern throughout most of the twentieth century of declining lake levels, although with notable exceptions. Possible causes of lake level changes are assessed briefly, but the main objective is to present a regional and long-term perspective on lake level records.