Seminar Abstract

Richard Palmer and Matthew Wiley

Thursday, January 26, 2006

Climate and land use change impacts on the endangered Chinook salmon populations in the Snohomish River Basin, Washington

Climate change will have a significant impact on streamflows in the Pacific Northwest and the potential impacts of climate change on any long-term management plan should be assessed. The projected increases in average temperature will alter whether precipitation falls as rain or snow, when snow melts, and the associated effects of theses processes on streamflows. These hydrologic changes are likely to have a significant impact on endangered populations of anadromous fish.

This research explores the potential impacts of future climate and land use change on the effectiveness of a set of proposed salmon recovery strategies adopted by a watershed-planning group in the Snohomish River Basin, WA. We use three process-based models to examine the predicted outcomes of planned habitat restoration actions under different future scenarios. General Circulation Model (GCM) output is used to force a hydrologic model (DHSVM- Distributed Hydrology Soil- Vegetation Model) that predicts streamflow and stream temperature based on land cover, topography, and meteorology. The outputs from DHSVM are linked to a salmon life cycle model (SHIRAZ) which uses information on water temperature, water flow, sediment, and habitat quality indicators to predict salmon population status over time.

The Snohomish Basin Salmonid Recovery Technical Committee developed a technical foundation for the Snohomish Basin Salmonid Conservation Plan, in which four alternative future scenarios of habitat protection and restoration are generated. We examine the robustness of estimated effects of two of these land use restoration scenarios to future climate conditions. Future climate scenarios for the years 2025 and 2050 are derived from outputs of the Hadley Center's HADCM3 and the Geophysical Fluid Dynamics Laboratory's R30 GCMs.

Speaker bio:

Prof. Rick Palmer currently teaches courses and performs research at the UW's Department of Civil and Environmental Engineering on the topics of water resource management, optimization and simulation techniques, risk analysis, systems analysis, and expert systems. Prof. Palmer is a member of the American Society of Civil Engineers and a principal in the Climate Impacts Group.

Matthew Wiley is a research engineer at the UW's Department of Civil and Environmental Engineering and a member of both the Climate Impacts Group and the Puget Sound Regional Synthesis Model group. Matt's research projects are primarily focused on streamflow forecasting across a range of timescales and the application of these forecasts to water resource management decisions.