Gathering Information on the Future of Snow and Water for Adaptation Planning on National Forests
Charles Luce1
1U.S. Forest Service
As the climate changes, the US Forest Service is considering how climate change is expected to affect water resources when developing Forest Plans and Project Plans. Consideration of Climate Change is a requirement of the 2012 planning rule, and there is a need for authoritative, easily accessed, and easily applied information about expected changes for National Forest planners, watershed, fish, and wildlife specialists, along with interested stakeholders. In broad terms, increased carbon dioxide is warming air temperatures, leading to observations of and expectations for warmer streams, reduced snowpacks, increased wildfire risk, and altered streamflow characteristics. Each of these, in turn is expected to affect species distributions, biotic interactions, migration, and population viability. Evaluating these changes and preparing to adapt to them is a complex process of considering how global-scale changes manifest at regional levels and how those changes will play out for local watersheds, ecosystems, and the people who live in them. The question is complex not just in terms of the natural history, but in navigating the many potential sources of information.
One tool developed by Forest Service Research and Office of Sustainability and Climate is a set of maps of expected changes in temperature, precipitation characteristics, snowpack storage metrics, stream temperature measures, and a suite of streamflow metrics. All calculations are based on well-vetted downscaling methods and snowpack, hydrology, and temperature models backed by substantial peer reviewed research. The maps are updated as time and supporting data allow. Climate and snowpack metrics are provided on 4-km grids while streamflow and temperature data are provided on National Hydrography Dataset stream segments. This map resolution is intended to provide specialists and managers with enough information to understand general expectations of differences and variations in climate and water changes across important gradients within each National Forest System unit.
This tool provides a simple entrée for people with diverse scientific backgrounds to local estimates of terrain dependent effects on snow and water at the scale of a National Forest. This scale offers stakeholders and personnel a perspective on potential changes couched in terms of landscapes with which they are familiar, provoking curiosity and insights about how basic changes in water balance and timing might affect resources and infrastructure in which they are interested. In this way, we seek to encourage a coproduction of understanding by leveraging maps that have a somewhat general climatological basis against local professional and stakeholder knowledge about resources and their sensitivities to produce assessments of vulnerability and plans for adaptation.