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• 1. [Article] Undercut streambanks in forested headwater streams of the Oregon coast range

  This study was undertaken to evaluate the occurrence and characteristics of undercut streambanks in forested headwater streams of the Oregon Coast Range. Undercut streambanks and associated reach characteristics ...

  Citation × Citation Citation Abstract Copy Title: Undercut streambanks in forested headwater streams of the Oregon coast range Author: Salminen, Edward M. This study was undertaken to evaluate the occurrence and characteristics of undercut streambanks in forested headwater streams of the Oregon Coast Range. Undercut streambanks and associated reach characteristics were surveyed along 46 sample reaches (each 152 m in length) in 8 streams; all sample reaches occurred in unmanaged forested riparian areas. Drainage areas ranged from 0.3 to 16.6 km^2. At each undercut location length, surface area, volume, low-flow (summertime) volume, and maximum horizontal depth were measured. Individual undercuts had surface areas ranging from 0.3 to 27.7 m^2 with a mean value of 2.6 m^2, and lengths ranging from 1.2 to 15.2 m with a mean value of 5.0 m. The area undercut streambanks ranged from 0.0 to 27.4 m^2 / 100 m of stream, with an average value of 6.5 m^2 / 100 m. The proportion of bankfull channel area undercut ranged from 0.0 to 4.5%, with an average value of 1.1%. Reach length undercut ranged from 0.0 to 23.6%, with an average value of 6.2%. The values reported in this study are approximately mid-range in comparison to characteristics of undercut banks reported in studies from Alaska, Montana, and Wisconsin. The % of reach area covered by undercut streambanks in this study is approximately half of that provided by large woody debris. Outside channel bends had approximately 6 times more undercut streambanks than inside bends or straight sections. Streams having a sinuosity index greater than 1.15 averaged approximately twice as much % surface area undercut than streams having a sinuosity index less than 1.15. Number of undercuts and undercut characteristics were inversely correlated with channel gradient; significant differences occurring among 1%, 2-4%, and 5+% channel gradient classes. Streambanks ranging in height from 1-2 m had a higher occurrence of undercut streambanks than either lower or higher streambanks. Undercut streambanks were 4 times more common in "composite" than "non-composite" streambanks. Undercut characteristics appear to be correlated with valley segment type. Channel widths were, on average, significantly narrower at undercut sites when compared to reach average channel widths. However, it does not appear than width characteristics are a cause of undercutting. Based on field observations it appears that flow obstructions (gravel bars, boulders, large woody debris) have little impact on undercut characteristics. Both at-a-site and reach-level comparisons of undercut bank characteristics showed relatively strong correlations with streamside tree densities. Red alder (Alnus rubra) is the most prevalent species found in Coast Range riparian areas, and the most significant species in explaining reach-level differences in undercut characteristics. Sitka spruce (Picea sitchensis) is less common in riparian zones, but appears to be positively correlated with the proportion of reach area undercut. Title: Undercut streambanks in forested headwater streams of the Oregon coast range Author: Salminen, Edward M. This study was undertaken to evaluate the occurrence and characteristics of undercut streambanks in forested headwater streams of the Oregon Coast Range. Undercut streambanks and associated reach characteristics were surveyed along 46 sample reaches (each 152 m in length) in 8 streams; all sample reaches occurred in unmanaged forested riparian areas. Drainage areas ranged from 0.3 to 16.6 km^2. At each undercut location length, surface area, volume, low-flow (summertime) volume, and maximum horizontal depth were measured. Individual undercuts had surface areas ranging from 0.3 to 27.7 m^2 with a mean value of 2.6 m^2, and lengths ranging from 1.2 to 15.2 m with a mean value of 5.0 m. The area undercut streambanks ranged from 0.0 to 27.4 m^2 / 100 m of stream, with an average value of 6.5 m^2 / 100 m. The proportion of bankfull channel area undercut ranged from 0.0 to 4.5%, with an average value of 1.1%. Reach length undercut ranged from 0.0 to 23.6%, with an average value of 6.2%. The values reported in this study are approximately mid-range in comparison to characteristics of undercut banks reported in studies from Alaska, Montana, and Wisconsin. The % of reach area covered by undercut streambanks in this study is approximately half of that provided by large woody debris. Outside channel bends had approximately 6 times more undercut streambanks than inside bends or straight sections. Streams having a sinuosity index greater than 1.15 averaged approximately twice as much % surface area undercut than streams having a sinuosity index less than 1.15. Number of undercuts and undercut characteristics were inversely correlated with channel gradient; significant differences occurring among 1%, 2-4%, and 5+% channel gradient classes. Streambanks ranging in height from 1-2 m had a higher occurrence of undercut streambanks than either lower or higher streambanks. Undercut streambanks were 4 times more common in "composite" than "non-composite" streambanks. Undercut characteristics appear to be correlated with valley segment type. Channel widths were, on average, significantly narrower at undercut sites when compared to reach average channel widths. However, it does not appear than width characteristics are a cause of undercutting. Based on field observations it appears that flow obstructions (gravel bars, boulders, large woody debris) have little impact on undercut characteristics. Both at-a-site and reach-level comparisons of undercut bank characteristics showed relatively strong correlations with streamside tree densities. Red alder (Alnus rubra) is the most prevalent species found in Coast Range riparian areas, and the most significant species in explaining reach-level differences in undercut characteristics. Sitka spruce (Picea sitchensis) is less common in riparian zones, but appears to be positively correlated with the proportion of reach area undercut. Close

• 2. [Article] A resource survey of river energy and low-head hydroelectric power potential in Oregon

  The project was funded by the United States Department of Energy. Contract No. EG-77-S-07-1691 through the Idaho Water Resources Research Institute.

  Citation × Citation Citation Abstract Copy Title: A resource survey of river energy and low-head hydroelectric power potential in Oregon Author: Klingeman, Peter C., Oregon State University. Water Resources Research Institute, Idaho Water Resources Research Institute, State of Washington Water Research Center, Montana University Joint Water Resources Research Center The project was funded by the United States Department of Energy. Contract No. EG-77-S-07-1691 through the Idaho Water Resources Research Institute. Title: A resource survey of river energy and low-head hydroelectric power potential in Oregon Author: Klingeman, Peter C., Oregon State University. Water Resources Research Institute, Idaho Water Resources Research Institute, State of Washington Water Research Center, Montana University Joint Water Resources Research Center The project was funded by the United States Department of Energy. Contract No. EG-77-S-07-1691 through the Idaho Water Resources Research Institute. Close

• 3. [Image] Sports fishery

  	Sports fishery along left shore (Oregon side) of Columbia River below mouth of Sandy River
  	Citation × Citation Citation Abstract Copy Title: Sports fishery Year: 1945 Sports fishery along left shore (Oregon side) of Columbia River below mouth of Sandy River Title: Sports fishery Year: 1945 Sports fishery along left shore (Oregon side) of Columbia River below mouth of Sandy River Close

• 4. [Image] White River falls

  	18 foot falls on the White River, tributary to the Deschutes River, several hundred yards below power plant. Upper falls can be seen faintly in background
  	Citation × Citation Citation Abstract Copy Title: White River falls Year: 1942 18 foot falls on the White River, tributary to the Deschutes River, several hundred yards below power plant. Upper falls can be seen faintly in background Title: White River falls Year: 1942 18 foot falls on the White River, tributary to the Deschutes River, several hundred yards below power plant. Upper falls can be seen faintly in background Close

• 5. [Image] Dam on Milton Creek near St Helens, Oregon

  	Citation × Citation Citation Abstract Copy Title: Dam on Milton Creek near St Helens, Oregon Year: 1946 Title: Dam on Milton Creek near St Helens, Oregon Year: 1946 Close

• 6. [Image] Deschutes River horseshoe

  	The horseshoe bend in the Deschutes River, Oregon
  	Citation × Citation Citation Abstract Copy Title: Deschutes River horseshoe Year: 2004 The horseshoe bend in the Deschutes River, Oregon Title: Deschutes River horseshoe Year: 2004 The horseshoe bend in the Deschutes River, Oregon Close

• 7. [Image] Dam on Milton Creek near St Helens, Oregon

  	Citation × Citation Citation Abstract Copy Title: Dam on Milton Creek near St Helens, Oregon Year: 1946 Title: Dam on Milton Creek near St Helens, Oregon Year: 1946 Close

• 8. [Image] Dam on Milton Creek near St Helens, Oregon

  	Citation × Citation Citation Abstract Copy Title: Dam on Milton Creek near St Helens, Oregon Year: 1946 Title: Dam on Milton Creek near St Helens, Oregon Year: 1946 Close

• 9. [Image] Diversion dam near Prineville, Oregon

  	Crooked River diversion dam
  	Citation × Citation Citation Abstract Copy Title: Diversion dam near Prineville, Oregon Year: 1942 Crooked River diversion dam Title: Diversion dam near Prineville, Oregon Year: 1942 Crooked River diversion dam Close

• 10. [Image] Deschutes River above Bend, Oregon

  	Typical slow water section of Deschutes River above Bend, Oregon and Lava Island Falls
  	Citation × Citation Citation Abstract Copy Title: Deschutes River above Bend, Oregon Year: 1937 Typical slow water section of Deschutes River above Bend, Oregon and Lava Island Falls Title: Deschutes River above Bend, Oregon Year: 1937 Typical slow water section of Deschutes River above Bend, Oregon and Lava Island Falls Close