Oregon State University

Calendar

Calendars

Event Details

Willamette Water 2100 Project Webinar: Modeling ecohydrologic processes in mountain watersheds—implications for the Willamette Watershed

Naomi Tague and Elizabeth Garcia, UC-Santa Barbara

Friday, April 26, 2013 12:00 PM

Abstract: Mountain, snow-dominated watersheds in the Western U.S. provide multiple services. Two especially important services are the provision of water supply to human populations and maintenance of forested ecosystems that preserve water quality and sequester atmospheric carbon. Understanding what fraction of the hydrologic budget that forests consume via transpiration or their influence on the landscape’s evaporation budget remains an active area of research because of the many interacting climatic and landscape controls. We use a process-based model of coupled hydrologic and carbon cycling processes to estimate evapotranspiration (ET), forest productivity (NPP) and growth, and streamflow. The model allows us to detangle how historic climatic controls have influenced forest water use, and concomitantly, basin streamflow. We show that despite receiving a substantial amount of annual precipitation in the HJ Andrews, the seasonality of precipitation relative to the growing season renders a large fraction of that water unavailable to the forests. Instead, forest ET is largely controlled by the landscape’s soil water holding capacity—or the geologic properties that hold snowmelt on the landscape later into the growing season. Other watersheds in the Western US, such as those in the California Sierra or Colorado Rockies, show much greater sensitivity to the timing of melt and how much incoming precipitation falls as snow versus rain.  The spatial differences in the sensitivity of forest water use to warming can have important implications for streamflow but also for forest vulnerability to disturbances, including fire and drought related dieback and disease. To show this, we present results from a study in New Mexico where the spatial pattern of drought-related forest dieback was related to these geo-climatic controls on forest water availability and use.  Our model-based analysis for forest and streamflow responses to warming for small watersheds in different geo-climatic settings in the Western US provides a more mechanistic understanding of watershed sensitivity to climate warming.

This seminar can also be viewed online: http://live.oregonstate.edu .  Please sign in to the chat window with: First Name_Last Name_OrganizationAbbreviation so you can ask questions during and after the seminar and we can track who is watching online.  You will need to use underscores rather than spaces when you sign in and there is a limit of about 30 characters.

This seminar is sponsored by the Willamette Water 2100 Project, a project evaluating how climate change, population growth, and economic growth will change the availability and the use of water in the Willamette River Basin (WRB) on a decadal to centennial timescale.

 

 


Kidder Hall (campus map)
http://live.oregonstate.edu
202
Maria Wright
1 541 737 6148
maria.wright at oregonstate.edu
Water/Watershed Institut
This event appears on the following calendars: