Thesis
Spatial and temporal precipitation and their effects on Queets Watershed runoff in the Olympic Experimental State Forest
Washington State University
Master of Science (MS), Washington State University
2010
Handle:
https://hdl.handle.net/2376/101946
Abstract
Hydrologic characteristics of the mountainous Olympic Peninsula in western Washington State are unique due to the regions' proximity to the Pacific Ocean. Abundant moisture and steep terrain result in significant orographic precipitation that produces challenging land management decisions regarding timber harvesting activities in the Olympic Experimental State Forest (OESF) especially when factoring climate change into future runoff predictions. Two important issues are examined in this paper. First, the spatial extrapolation of topographic precipitation variation from sparse weather data is examined by evaluating PRISM adjusted precipitation in the OESF using a dynamic hydrology model called DHSVM. Second, while it is projected that increases in future monthly precipitation for the Olympic Peninsula are likely, little is understood about how the actual timing of these precipitation increases will impact future runoff and thus precipitation projections overall are highly uncertain. Using the DHSVM model, variations in temporal rainfall patterns under 3 different GCM projections for 2 climate scenarios representing 2050 climate change predictions were examined. It was determined that precipitation may be underestimated by as much as 61%. However, DHSVM runoff results do not compare with this underestimation with an under prediction of approximately only 9% for the 2006 water year. In addition it has been shown that accurate daily time scale increments of precipitation are needed in order to predict the magnitude of peak runoff events and total annual runoff under different climate change scenarios. It was found that average annual flow could vary by more than 23% from the current average flow for the Queets basin across different time scales. In addition, it was determined that peak runoff events could vary by more than 40,000 ft3 /s (1,133 m3 /s) in magnitude. These results demonstrate the need for accurate spatial interpolation and reliable down scaling techniques used for future precipitation projections when attempting to predict landslides.
Metrics
1 File views/ downloads
12 Record Views
Details
- Title
- Spatial and temporal precipitation and their effects on Queets Watershed runoff in the Olympic Experimental State Forest
- Creators
- Travis E. Lopes
- Contributors
- Michael E. Barber (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Civil and Environmental Engineering, Department of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; Pullman, Wash. :
- Identifiers
- 99900525178901842
- Language
- English
- Resource Type
- Thesis