Ecological Drought in the Southwest United States: Confronting a hotter future
The Southwest’s landscapes are some of the most stunning in the country, ranging from the Grand Canyon to snowcapped mountains. These landscapes support the plants and wildlife that define the region, provide recreation, and have fostered a long history of human livelihoods and ecological diversity. For example, the region is home to numerous natural and cultural resources that support wildlife watching, hunting, fishing, skiing, and more. Together, these activities contribute billions of dollars to the region’s economy each year. Now, hotter and longer droughts are challenging resource managers to find innovative ways to adapt to this new standard.
It’s well known that the southwestern United States is no stranger to drought and high temperatures. In fact, unique adaptations to drought have led to the amazing diversity of plant and animal life found in this region. However, warming temperatures are threatening the stability of that life by exacerbating the current water deficit, and it’s unclear how ecosystems will respond to these changes.
In light of these concerns, the Department of the Interior Southwest Climate Science Center (SW CSC) is working to identify how drought will manifest itself throughout the region and what these changing conditions could mean for ecosystems, wildlife, and the economy. In March 2017, a group of climate and ecological experts met to discuss ecological drought in the Southwest and identified several core issues.
Increasing water demands in a region of limited water supply: The Southwest has the fastest growth of population and development in the U.S., which increases the demand for limited water resources. Hotter droughts have resulted in record-low snowpack and reservoir levels, exacerbating the issue of over-allocation of water for human use. For example, the Colorado River Basin has been operating in a water deficit since the year 2000.
We risk losing our iconic landscapes: Drier soil and air increases the likelihood of wildfires, which in turn results in the loss of native vegetation. When rain does arrive, storms are often stronger, and can lead to severe erosion on burned mountain sides. This erosion ultimately reduces the water quality as increased amounts of sediment enter streams and rivers, and can overwhelm existing water infrastructure.
Nature’s benefits are at risk: Intact ecosystems provide many cultural, economic, and recreational benefits for residents and visitors of the Southwest. Fishing, skiing, farming, and tourism are at risk from increased temperatures, which result in decreased snowpack and water resources.
Although it’s normal for this region to go through periods of drought, changing climate conditions are increasing the vulnerability of the region’s fish, wildlife, natural features, water resources, and human populations to severe ecological droughts. In response, the SW CSC is collaborating with researchers and stakeholders to draw on lessons learned from recent droughts to develop effective plans for adaptation.
The March workshop was hosted in partnership by the SW CSC, the University of Maryland Center for Environmental Science Integration & Application Network, and the USGS National Climate Change and Wildlife Science Center. This was the eighth in a series of eight workshops being held across the United States, each in a different region. Each workshop results in a four-page informational document that synthesizes the current understanding of ecological drought in the region.
To view the informational document from the Southwest workshop and learn more about ecological drought in the Southwest, please click here.
Learn more about Ecological Drought in other regions of the U.S. here
Graphic: Colorado River Basin historical water supply and use. Data from U.S. Department of the Interior Bureau of Reclamation. Credit: UMCES-IAN