ETD RECORD
Quantification of reservoir operation-based losses to floodplain physical processes and impact on the floodplain vegetation at the Kootenai River, USA
Citation
Benjankar, Rohan Man.. (2009). Quantification of reservoir operation-based losses to floodplain physical processes and impact on the floodplain vegetation at the Kootenai River, USA. Theses and Dissertations Collection, University of Idaho Library Digital Collections. https://www.lib.uidaho.edu/digital/etd/items/etd_17.html
- Title:
- Quantification of reservoir operation-based losses to floodplain physical processes and impact on the floodplain vegetation at the Kootenai River, USA
- Author:
- Benjankar, Rohan Man.
- Date:
- 2009
- Keywords:
- Floodplain ecology--Kootenai River Floodplain ecology--Kootenai River Valley Vegetation mapping--Kootenai River Valley
- Program:
- Civil Engineering
- Abstract:
- The Kootenai River ecosystem has been subject to many human influences, which peaked with the construction and subsequent operation of Libby Dam. The major consequences of these human alterations are modified fluvial processes, altered hydroperiod and nutrient exchange on the floodplain, limited regeneration of riparian forests, and elimination of habitats essential for native fish. The main goal of the current study was to develop an integrated hydrodynamic and vegetation model that subsequently can be used as a tool to quantify operational losses due to Libby Dam and for assessing different restoration strategies.;The integrated hydrodynamic (HD) models were used to simulate historic, pre-dam, and contemporary scenarios for a study area of approximately 200 km 2 of floodplain. A new vegetation model "CASiMiR-vegetation" was developed to simulate the spatial dynamics of vegetation succession and changes between different scenarios. The vegetation dynamics are based on existing theory but adapted to observed field data on the Kootenai River. The model simulates the changing vegetation patterns on an annual basis from a specific initial condition based on spatially distributed physical parameters. The model was calibrated and the robustness of the model was analyzed.;In this pilot study, the effects of the dam operation were for the first time numerically quantified and differentiated from other causes. The HD model results indicated that the active floodplain is almost extinct and different physical processes (inundation extent, water depth, velocity, shear stress) are reduced extensively as compared to the historic condition prior to the dam construction. The vegetation model demonstrated that the colonization phase is drastically reduced, and this has led to the domination of mature phase vegetation in the years since the dam went into place.;In a second stage the effectiveness of breaching levees as a means of restoring some floodplain functions and natural vegetation was assessed. The simulations showed that the floodplain would reconnect with the main channel in a historic 1.1 year flood. The same level of connectivity would not occur in the existing no-breach condition even with a 25 year flood. The vegetation model was then used to simulate that in the area influenced by the levee breach a natural floodplain vegetation pattern could be restored.
- Description:
- Thesis (Ph. D., Civil Engineering)--University of Idaho, August 2009.
- Major Professor:
- Klaus Jorde.
- Defense Date:
- August 2009.
- Type:
- Text
- Format Original:
- xx, 288 leaves :col. ill., col. maps ;29 cm.
- Format:
- record
Rights
- Rights:
- In Copyright - Educational Use Permitted. For more information, please contact University of Idaho Library Special Collections and Archives Department at libspec@uidaho.edu.
- Standardized Rights:
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