Details

Autor(en) / Beteiligte

• Duncan, Leslie Lyons

Titel

Regional and Local Hydrologic Responses to Climate Fluctuations and Land Use Change, Columbia River Basin, Washington

Ort / Verlag

ProQuest Dissertations & Theses

Erscheinungsjahr

2017

Quelle

ProQuest Dissertations & Theses A&I

Beschreibungen/Notizen

• The research presented herein incorporates three objectives, narrowing from the broad, basinscale, temporal and spatial hydroclimatology to the regional landsliding activity and finally to the local GW-SW interaction between the bluffs and the river, in order to explore the effects of climate and land use change across the multiple scales of impact. Water and its effects are often implicated as causes of slope failure; therefore, the overall research goal of this work is to develop a quantitative description of the hydrological conditions of the Locke Island landslide and the White Bluffs. Natural climate variability and land use change can increase recharge to the groundwater system, which, in turn, can increase storage within the system and discharge from the system. The two main research goals of this work are: (1) to understand the impacts of climate variability on the regional subsurface conditions, and (2) to understand the impacts of land use change on the regional and local subsurface conditions. The Palmer Drought Severity Index (PDSI) is used as a measure of subsurface moisture. Since this particular metric can be calculated at any spatial scale for which input data exists, two corollary research objectives of this work are: (1) to determine how representative regional PDSI values are of finer-scale PDSI values, and (2) to determine the conditions that control the differences in PDSI values between the two spatial scales. In assessing the impacts of climate variability on regional subsurface conditions, two seconday research objectives of this work are: (1) to determine the existence of low frequency periods of wetness and dryness over the Pacific Northwest of the United States, and (2) to assess solar insolation as a forcing mechanism for any low frequency periods of wetness and dryness. In examining the impacts of land use change on regional and local subsurface conditions, a secondary research objective of this work is to determine the groundwater flow response to changes in subsurface recharge from dam-induced river fluctuations, local irrigation wastewater ponds, and increased regional precipitation. (Abstract shortened by ProQuest.)