Late 18th century drought-induced sand dune activity, Great Sand Hills, Saskatchewan. Late 18th century drought-induced sand dune activity, Great Sand Hills, Saskatchewan. Abstract Geomorphic evidence and optical ages from seven locations indicate that widespread dune activity occurred within the last 200 years in the Great Sand Hills region of southwestern Saskatchewan. During this interval, parabolic dunes were active in all areas studied. These ages indicate that the most recent interval of activity was initiated about AD 1800, and continued at a level higher than present for approximately 80 years.
Dunes affected by such climatically induced regional activity require many decades to restabilize.
Historical observations show that dunes in this area have been restabilizing throughout the 20th century. For the southern Canadian Prairies, a region with serious concerns about the implications of global warming, this study highlights the sensitivity of sand dunes to drought and cumulative moisture stress.