The seasonal snowpack has a dominating role in physical, chemical, and biological processes occurring in most western North American watersheds. Snow is a natural water storage mechanism and is therefore the determinant of hydroelectric production, irrigation, and aquatic health. Snowmelt also triggers the growing season, and earlier snowmelt appears to initiate summer landscape drying, accentuating drought conditions and recently accelerating the frequency of major wildfire events. The inability of current methods to forecast (or even backcast) the temporal and spatial response of snow water dominated river basins to natural or human disturbances, including variations in climatic conditions, hinders our ability to fully understand and thus manage these watersheds. New approaches are needed to extrapolate snow water equivalent measurements over complex landscapes, model temporal and spatial basin water yields and predict ecologic and hydrologic response to local disturbance, regional climate change and extreme events. This project aims to understand fundamental relationships between climate change, snowpack, and runoff in the northern Rocky Mountains. The research approach presented is based on existing observations and theories about snow-dominated watersheds; both process-based research and hydrologic observatory design questions/hypotheses are posed. The research will use integrated physical and ecologic modeling to link three different hydrologic settings: 1) Paleo-Hydrology; 2) Historical to present hydrology, and; 3) Future Hydrology. The snow component of the work plan will emphasize estimating spatial variability of snowpack characteristics at the local to the regional length scale and developing a suite of time/space snowpack models, as input forcing to watershed models. Runoff trends will be analyzed with the goal of determining the amount of change and variability of the instrumental records. Runoff analysis will integrate snow data, automatic weather station data, and remote sensed data with field water quality data and runoff records to look at the continuum of processes releasing water from basins are several scales. Time and space scales of forcing/response will be elucidated using an integrated physical-ecologic model system (RHEESys). The model will be used to simulate watershed processes during the instrumental era, and past hydrologic and ecologic responses to known megadroughts, These modeling results will guide simulations of future change within this snow dominated watershed. Broader Impacts Broader impacts from this project will be in three areas: formal education; informal education; and science experience for under-represented groups. University of Montana students will be involved in the research at the graduate to undergraduate levels and information from this work will be incorporated into numerous courses taught by the PIs. Because of the broad nature of this research it gives tremendous opportunity for teaching interdisciplinary concepts and tools in the formal university environment. In addition, the spectacular landscapes of the region draws at least two million tourists each year. We will reach this audience through presentations within Glacier National Park's public lecturing program, lectures to Park and other local educators and interpreters, and active participation with a regional science and management conference. We will also pursue a program to create and install interpretative display panels on climate change and the hydrologic cycle, from past mega-droughts to current and future changes. We will also expand our working relationship with both the Confederated Salish-Kootenai Tribe's hydrology program and tribal college. Tribal staff and student interns will be involved in field research and analyses. The long-term goal is to develop joint research on Tribal lands within the region.
