The Prairie Ecozone is the only major region of Canada where drought is a landscape hazard; aridity is linked to soil erosion. Management of prairie ecosystems and
soil landscapes therefore requires an understanding of past and future trends and variability in regional aridity. We used instrumental and paleoclimatic records to define a
regional baseline for prairie aridity, to evaluate the utility of modern climate normals (i.e.1961-1990) as a benchmark for future climatic change, and to provide a historical context for a range of General Circulation Model (GCM) forecasts of regional aridity. A warmdry scenario derived from the Canadian GCM projects a significant increase in the area of subhumid and semiarid climate.
