Navajo Nation Sand Dunes Increasing Study Indicates

A decade-long federal study says that a drier climate on the Navajo Nation​ is causing sand dunes to grow and move, potentially threatening grazing, health, infrastructure, and livelihood. The study by a U.S. Geological Survey geologist found that sand dunes are growing fast and moving more, including old dunes that previously were stable. Some of the sand dunes are moving at a rate of 115 feet per year, the report found. More than a third of the 27,000-square-mile reservation is covered by sand dunes and sand sheets, and it has experienced varying degrees of drought for the past 15 years. Geologist Margaret Hiza Redsteer called the Navajo Nation—specifically the southwestern portion in Arizona—"just on the edge of being habitable." Her work also noted the vulnerability of indigenous people who rely heavily on the land. "The annual moisture here has historically been just enough to get by," she said in a statement. "When there is even a small change, there is a huge effect."  
The areas that call for the most alarm are the lands near the Colorado Plateau, located near Flagstaff, Arizona, and surrounding the Hopi reservation. Redsteer found that besides growth and new movement in existing dunes, new dunes were increasing in number. The new dunes form downwind from rivers and washes, largely from dry, wind-blown river sediment. For instance, the dune field outside Flagstaff, has grown by 70 percent since 1995, when the most recent drought gripped the Nation.