The Cuesta del Viento (Wind Slope) Reservoir formed behind a large dam that was constructed on the Jáchal River in 1997–1998 in the San Juan Province of Argentina.



Surrounded by spectacular mountains, the reservoir controls the flow of streams from snowmelt of the Andes Mountains and provides a source of irrigation for fruit plantations and other crops. The reservoir has also become a popular destination for windsurfing and kitesurfing because of the consistent afternoon winds that reach 30–40 knots (55–74 km/hour; 34–46 mi/hour). These powerful winds are caused by the daily flow of air currents that travel out of the eastern Andes Mountains and converge in the river valley.

These Landsat images show the area in November 1996 (before the dam was built) and December 2013. The inclusion of Landsat’s shortwave infrared band information for this image pair also highlights the geologic features of the area.

Landsat images provide an unbiased view of features on the Earth’s surface and the changes that take place on the landscape.