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Earth Sciences

Central Washington University

All Master's Theses

Floods

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Full-Text Articles in Physical Sciences and Mathematics

Paleoflood Record Reconstruction At An Archaeological Site On The Owyhee River, Southeastern Oregon, Stephanie Louise Vandal Jan 2007

Paleoflood Record Reconstruction At An Archaeological Site On The Owyhee River, Southeastern Oregon, Stephanie Louise Vandal

All Master's Theses

The magnitude and frequency of late Holocene floods on the Owyhee River in southeastern Oregon were reconstructed from fine-grained flood deposits at three sites in the river canyon. The stratigraphy at the Birch Creek study site (BCSS) preserves a record of seven to nine large floods from the last 2800 years. Two additional study sites, the Iron Gate and Waterwheel, within a 5-km reach of the BCSS, showed 18-26 floods from the late Holocene to 1993 A.D. and 17-22 floods from 8600 B.P. to 1993 A.D., respectively. Hydrologic Engineering Center-River Analysis System modeling of the 1993 flood and several paleofloods …


The Role Of Geomorphic Features And Hydrologic Processes On Sediment Clusters In Gravel-Bed Rivers, Washington: A Field-Based Approach, Ross Richard Hendrick Jan 2005

The Role Of Geomorphic Features And Hydrologic Processes On Sediment Clusters In Gravel-Bed Rivers, Washington: A Field-Based Approach, Ross Richard Hendrick

All Master's Theses

This project investigated the movement and evolution of sediment clusters after four separate flood events at two geomorphically different sites along the Entiat River, Washington. Clusters are defined as an obstacle or anchor clast(s) that impede the progress of two or more sediment particles, and are believed to be an important characteristic of the variable bed topography of gravel-bed rivers. Detailed field descriptions and digital photographs of clusters were used to determine the characteristics of clusters at chosen locations on gravel bars regularly covered by high flow events. Data were collected during low-flow conditions, and clusters were re- examined and …


A Large Late Pleistocene Outburst Flood From Pluvial Lakes Alvord And Coyote Into The Owyhee River, Oregon, Deron Torrey Carter Jan 2004

A Large Late Pleistocene Outburst Flood From Pluvial Lakes Alvord And Coyote Into The Owyhee River, Oregon, Deron Torrey Carter

All Master's Theses

A large late-Pleistocene flood traveled into the Owyhee River as a result of a rise and subsequent outburst from pluvial Lake Alvord in southeastern Oregon. Lake Alvord breached Big Sand Gap after reaching an elevation of 1292 m, releasing 11.3 km3 into the adjacent Coyote Basin before stabilizing at an elevation of about 1280 m. Overflow then spilled out of the Coyote Basin through two outlets at 1278 m and into the Crooked Creek drainage of the Owyhee River. The flood created a series of deeply incised canyons, scabland topography and deposited numerous boulder bars containing imbricated clasts up to …


A Small Look At The Big Picture: Linking Geopotential Height Anomalies To Paleofloods On The Snake River, Idaho And Oregon, Gwendolyn Bernitha Rhodes Jan 2001

A Small Look At The Big Picture: Linking Geopotential Height Anomalies To Paleofloods On The Snake River, Idaho And Oregon, Gwendolyn Bernitha Rhodes

All Master's Theses

A combined paleoflood and flood hydroclimatology study on the Snake River in Idaho and Oregon suggests a link between floods and patters of geopotential height anomalies over the North Pacific Ocean. Examination of the paleoflood record in two 4-m (12 ft) tall terraces along the Hells Canyon reach of the Snake River in Idaho and Oregon shows evidence of at least twenty-two late-Holocene extreme floods that occurred approximately 5,000 years. The ages of paleoflood deposits at these sites fall into two time periods, from 5130 ± 40 to 1960 ± 40 yr BP and from 320 ± 40 yr BP …


Factors Contributing To Landslide Activity In The Winter Of 1995-96, Clearwater County Near Orofino, Idaho, Aaron Paul Wisher Jan 1998

Factors Contributing To Landslide Activity In The Winter Of 1995-96, Clearwater County Near Orofino, Idaho, Aaron Paul Wisher

All Master's Theses

Significant landslide activity occurred in Clearwater County, Idaho in November 1995 and February-May 1996. Mass wasting in the study area consisted of debris slides and earthflows triggered by rain-on-snow weather events. It is important to determine what factors contribute to landsliding in this area so that reliable prediction can reduce the destruction of property. Through field observation and aerial photo analysis, the factors contributing to landslides were studied. The objectives included a study of the geology, soils, aspect, slope gradient, vegetation and slope position related to each slide. Also a goal was to assess the role of land use in …