Sunday, October 23, 2011

Navajo memory complements science in study of climate change

US Geological Survey: The sand dunes among which Navajos have eked out austere livings for generations are growing fast and becoming mobile as the climate changes, says U.S. Geological Survey geologist Dr. Margaret Hiza Redsteer, whose interviews with elders and historical research augment her decade-long research on Navajo Nation land. Redsteer will discuss her work Friday, Oct. 21 at the annual conference of the Society of Environmental Journalists in Miami, as part of a panel on "Climate Change and Indigenous Peoples on the Frontlines."

One third of the Navajo Nation is sand dunes, much of it stabilized to varying degrees by vegetation that holds moisture and provides livestock range. Some of the dunes are very old; others date from the 1950s, when drought and wind mobilized sediment from floods on the Little Colorado River. Now, after severe drought has gripped the region with varying but persistent severity from 1996 to 2011, new dunes are increasing in number and previously inactive dunes are on the move. The new dunes form downwind from rivers and washes, largely from dry, wind-blown river sediment. In the Grand Falls area of the southwest Navajo Nation, dunes have grown 70 percent since 1995 and are moving northeast at a rate of 115 feet per year.

Dune mobility can threaten roads and buildings, as well as the livestock raising vital to the Navajo economy and indispensable to its culture. It is one of many signs of the region’s increased aridity. Redsteer and the USGS Navajo Land Use Planning Project, under license to and in collaboration with the Navajo Nation, are mapping the area’s geology and documenting its changes to help Navajo leaders plan for the challenge.

In addition to using ground-based lidar measurements, meteorological monitoring, GPS and aerial and satellite imaging, Redsteer drew on more than 70 elders living in the southwestern Navajo Nation to record observed changes in land use practices, as well as weather, vegetation, location of water sources and the frequency of wind and dust storms. The interviews helped corroborate USGS science....

In the Painted Desert in Arizona, part of the Navajo Nation. Image shot by Doug Dolde and released into the public domain

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