Thesis
Modeling the impacts of climate change and agricultural management practices on surface erosion in a dryland agricultural basin
Washington State University
Master of Science (MS), Washington State University
2011
Handle:
https://hdl.handle.net/2376/102861
Abstract
Soil erosion and sedimentation are a problem of interest for many land uses across the United States, particularly for agricultural areas where the soil surface is disturbed by harvest, planting, and cultivation of the soil. The objective of this study is to investigate the effects of climate change and agricultural land management on surface erosion and suspended sediment concentrations in the Potlatch River Basin. Because of certain cropping practices and rain-on-snow events, the Palouse region of northern Idaho and eastern Washington produce some of the highest sediment losses per acre in the United States. Climate change may lead to further problems if more frequent and intense storm events lead to a great amount of sediment generation. Many hydrological models have been developed which examine suspended sediment in river systems. The Potlatch River basin near Julietta, ID was examined using the Distributed Hydrology Soil Vegetation Model (DHSVM). The model was used to evaluate channel and soil surface erosion, as well as sediment yield in streams. DHSVM was calibrated using observed streamflow (2003 - 2010), evaluatedover the historical period of streamflow (1966 - 1984), and was also used to predict results for the year 2045 using statistically downscaled global climate data. The results show that as the projected climate-driven intensity of storms increase, more runoff is predicted in the Potlatch River Basin. Three tillage scenarios were incorporated into DHSVM for winter wheat cultivation: conventional till, reduced till, and no till. Sensitivity of the model to surface erosion and changes in channel sediment bed depth were both evaluated for several parameters that relate to erosion. Observations have shown that suspended sediment concentrations can drastically increase in this river, but model results do not yet display large fluctuations in suspended sediment concentrations which are typically observed in nature as a result of storm and erosion events. In the long-term, continued improvements to this preliminary model of the Potlatch River Basin can provide better insight into the effects of climate change on the riparian habitat of rainbow and steelhead trout in the basin and the sediment budget of the surrounding area.
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Details
- Title
- Modeling the impacts of climate change and agricultural management practices on surface erosion in a dryland agricultural basin
- Creators
- Erika Michelle Ottenbreit
- Contributors
- Jennifer C. Adam (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
- 99900525020101842
- Language
- English
- Resource Type
- Thesis