Drought is a pervasive theme for the American Southwest, with effects that are complex and multifaceted. Human population growth, additional land and water uses by people, and climate change are expected to exacerbate the frequency and severity of future droughts in the Southwest, as well as many other regions of the United States.
A workshop, the second in a series of U.S. Geological Survey (USGS) Southwest Region “Science Exchange” annual meetings, focused on USGS drought science. The workshop brought scientists and program managers from USGS together with representatives from the Bureau of Land Management, National Oceanic and Atmospheric Administration, Bureau of Reclamation, and state water management departments. The participants considered how extreme drought conditions are evolving in much of the American Southwest, with an emphasis on integrated drought science planning at the USGS bureau and program levels.
Topics covered in presentations and demonstrations were broad ranging and included monitoring for drought early warning, water use and water production associated with petroleum production, paleoperspectives on drought, and ecological consequences of drought for native fish.
The workshop did not limit discussion to the loss of water supply during drought. For example, participants provided multiple lines of evidence showing that drought can act as a stressor to environmental conditions that contribute to the severity of a range of other disasters, including fire, floods, and increased stress on natural ecosystems. One such presentation highlighted how drought increases both the likelihood and intensity of wildfires: Wildfires remove stabilizing vegetation, which increases runoff and erosion during periods of intense precipitation. This erosion results in excess sediment being deposited in watersheds, which then affects downstream water quality, storage, and supply.
Workshop participants stressed the need for more interdisciplinary science to support resource management decision systems. For example, one presentation highlighted the need for better integration of groundwater and surface water monitoring. Another presentation indicated that soil moisture is a better indicator of fire risk than the traditionally used surface water measurements.
Participants discussed not only the effect of drought on human activities but also the effect of human activities on mitigation or enhancement of drought conditions. Attendees recognized that integrated interdisciplinary approaches would be needed to explore this dynamic further. In addition, drought conditions are coupled to other factors, which attendees recognized can either help mitigate or exacerbate the “downstream” effects.
Attendees also considered foundational science requirements for improving our understanding of the complex effects of drought, focusing on two areas where they thought efforts could have the most impact: (1) enhanced integrated ecohydrologic monitoring and (2) development of integrated products at basin scales. Participants developed general concepts in these two areas as ways to contribute to future approaches to USGS drought science and coordination.
These recommendations were well received by meeting representatives from the USGS Southwest Region—they recognize that steps to foster new integrated science efforts will aid in bringing the full USGS capacity to bear on this national issue. The workshop’s discussion and the targeted recommendations for coordinated and multidisciplinary data collection, analysis, synthesis, and predictions will help the USGS with their principal objective of improving the understanding of drought processes and impacts on freshwater systems.
—Patrick Lambert, U.S. Geological Survey (USGS), Salt Lake City, Utah; Timothy Titus ([email protected]), USGS, Flagstaff, Ariz.; and Andrea Ostroff, USGS, Reston, Va.