Decadal-scale evolution of a small dune field: Keeler Dunes, California 1944–2010

Aerial photographs and satellite images have been used to document the evolution of a small (< 1 km2) dunefield over the past 60–70 years. Over this period, the dunefield has undergone significant changes, including development of well defined linear and crescentic dunes from an initial small area of partially vegetated dunes, resulting in an increase in the area of the dunes by a factor of 3 since 1944. The dune field continues to expand toward the southeast but its upwind margins are now experiencing significant erosion because the sand supply is now cut off by dust control measures in the source area and transport pathway. This study provides some information on the timescales of dune development in a high-energy aeolian environment, which formerly experienced an abundant supply of sand, with rapid development of crescentic dunes over a period of 20 years. The complexity of dunefield development is also highlighted, even on decadal timescales, and the important role of episodic sediment supply in forming new generations of dunes. Periods of rapid dunefield change involving lagged input of additional sand from external sources appear to be linked to episodes of high flows in the Owens River, which is the main sediment source for the Keeler Dunes.