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• 31. [Article] Right as rain? The value of water in Willamette Valley agriculture

  Signs of climate change across the Pacific Northwest indicate changing patterns of timing and availability of stream flow. Declining summer low flows, decreasing snow pack, higher temperatures and an increasing ...

  Citation × Citation Citation Abstract Copy Title: Right as rain? The value of water in Willamette Valley agriculture Author: Kalinin, Alexey V. Signs of climate change across the Pacific Northwest indicate changing patterns of timing and availability of stream flow. Declining summer low flows, decreasing snow pack, higher temperatures and an increasing fraction of mountain precipitation falling as rain, raise concerns about future reliability of stream flows. These changes will likely affect the agricultural economy and the balance between in stream and agricultural water uses, requiring a better understanding of how climatic factors and access to water affect farmers' livelihoods and the basin's economy. This study focuses on two economic questions about water and agriculture in the Willamette Valley. The first question asks: how sensitive is the value of water - as reflected in farmland rents - to variations in temperature, precipitation, soil quality and elevation? The results of a hedonic analysis provide insights into the potential effects of water scarcity that may result from climate change on economic returns to farmers. The second, related question seeks to understand the factors that affect farmers' decisions to exercise their water rights. Growers in the Willamette Valley do not always use their water rights, a surprising phenomenon compared to other farming regions in the western U.S. The analysis here estimates a logit model of farmers' field-level irrigation decisions. These decisions have quantitatively large implications for the consumptive use of water in the Basin overall. The relatively low estimated values for irrigation water rights (compared to other agricultural regions) reflect these patterns of intermittent use of those water rights. The comparison, however, between the per acre value of an irrigation water right and the incremental value of precipitation suggest that water has a similar value to farmers whether it comes as a right or as rain. Title: Right as rain? The value of water in Willamette Valley agriculture Author: Kalinin, Alexey V. Signs of climate change across the Pacific Northwest indicate changing patterns of timing and availability of stream flow. Declining summer low flows, decreasing snow pack, higher temperatures and an increasing fraction of mountain precipitation falling as rain, raise concerns about future reliability of stream flows. These changes will likely affect the agricultural economy and the balance between in stream and agricultural water uses, requiring a better understanding of how climatic factors and access to water affect farmers' livelihoods and the basin's economy. This study focuses on two economic questions about water and agriculture in the Willamette Valley. The first question asks: how sensitive is the value of water - as reflected in farmland rents - to variations in temperature, precipitation, soil quality and elevation? The results of a hedonic analysis provide insights into the potential effects of water scarcity that may result from climate change on economic returns to farmers. The second, related question seeks to understand the factors that affect farmers' decisions to exercise their water rights. Growers in the Willamette Valley do not always use their water rights, a surprising phenomenon compared to other farming regions in the western U.S. The analysis here estimates a logit model of farmers' field-level irrigation decisions. These decisions have quantitatively large implications for the consumptive use of water in the Basin overall. The relatively low estimated values for irrigation water rights (compared to other agricultural regions) reflect these patterns of intermittent use of those water rights. The comparison, however, between the per acre value of an irrigation water right and the incremental value of precipitation suggest that water has a similar value to farmers whether it comes as a right or as rain. Close

• 32. [Article] Irrigation decision survey data for the Willamette Water 2100 project

  [suggested citation: "Jaeger, William K. (2016): Irrigation decision survey data for the Willamette Water 2100 project. OSU Libraries. Dataset. http://dx.doi.org/10.7267/N9H12ZXK"]

  Citation × Citation Citation Abstract Copy Title: Irrigation decision survey data for the Willamette Water 2100 project Author: Jaeger, William K. [suggested citation: "Jaeger, William K. (2016): Irrigation decision survey data for the Willamette Water 2100 project. OSU Libraries. Dataset. http://dx.doi.org/10.7267/N9H12ZXK"] Title: Irrigation decision survey data for the Willamette Water 2100 project Author: Jaeger, William K. [suggested citation: "Jaeger, William K. (2016): Irrigation decision survey data for the Willamette Water 2100 project. OSU Libraries. Dataset. http://dx.doi.org/10.7267/N9H12ZXK"] Close

• 33. [Article] Hydrologic and Land Cover Effects on Sources and Fate of In-Stream Fluorescent Dissolved Organic Matter

  Dissolved organic matter (DOM) is a critical component of the carbon cycle linking terrestrial and aquatic ecosystems. Although many factors influence DOM fluxes and quality in rivers, controls on DOM ...

  Citation × Citation Citation Abstract Copy Title: Hydrologic and Land Cover Effects on Sources and Fate of In-Stream Fluorescent Dissolved Organic Matter Author: Lee, Baek Soo P. Dissolved organic matter (DOM) is a critical component of the carbon cycle linking terrestrial and aquatic ecosystems. Although many factors influence DOM fluxes and quality in rivers, controls on DOM compositions in catchments of the western U.S. are poorly understood. UV and fluorescent spectroscopy is a simpler, faster, and less expensive DOM fingerprinting technique compared to techniques, such as nuclear magnetic resonance (NMR) spectroscopy or wet chemical fractionation, and could be useful for characterizing complex DOM chemistry. However, only 1 % of DOM is estimated to be fluorescent, and the utility of UV and fluorescent spectroscopy for DOM characterization needs to be further investigated. This dissertation applied UV and fluorescent spectroscopy to examine hydrologic and land cover controls on DOM chemistry in streams of 45 catchments in the forested headwaters and a mixed landscape of the Willamette River Basin, Oregon, based on two years of monitoring. This dissertation contributes three major findings. First, freezing of water alters DOM chemistry by preferentially precipitating aromatic DOM. Second, UV and fluorescent spectroscopy was able to discriminate DOM delivered from highly processed, proteinrich deep subsurface sources during dry seasons especially in forested headwater streams of the H. J. Andrews Experimental Forest (HJA), where nitrogen inputs are very low. In addition, fluorescent DOM chemistry differed among watersheds with varying forest management history. Third, although fluorescent DOM in a headwater forested system differed among land use history, fluorescent DOM composition did not vary among streams draining a well-mixed landscape of urban, pasture/hay, forest, and agricultural land cover types in the central Willamette River Basin, where nitrogen inputs to streams are relatively high. Dissolved organic carbon (DOC) concentration decreased and the fluorescent index indicated an increase in terrestrial sources of DOM from small (1st and 2nd order) to large (4th to 6th order) streams. A protein-like DOM component that was detected in the headwater forested study site (HJA) was not detected in stream samples from the middle basin study site. These findings indicate that in-stream respiration, fueled by nutrient additions from agriculture runoff, consumes bioavailable, labile DOM (proteins) preferentially relative to more recalcitrant, terrestrial sources of DOM along water flow paths from headwater streams to major rivers. This study shows the clear applicability of the fluorescent characterization of DOM in identifying hydrologic and landscape controls as well as varying DOM chemistry and functions throughout watershed ecosystems. Title: Hydrologic and Land Cover Effects on Sources and Fate of In-Stream Fluorescent Dissolved Organic Matter Author: Lee, Baek Soo P. Dissolved organic matter (DOM) is a critical component of the carbon cycle linking terrestrial and aquatic ecosystems. Although many factors influence DOM fluxes and quality in rivers, controls on DOM compositions in catchments of the western U.S. are poorly understood. UV and fluorescent spectroscopy is a simpler, faster, and less expensive DOM fingerprinting technique compared to techniques, such as nuclear magnetic resonance (NMR) spectroscopy or wet chemical fractionation, and could be useful for characterizing complex DOM chemistry. However, only 1 % of DOM is estimated to be fluorescent, and the utility of UV and fluorescent spectroscopy for DOM characterization needs to be further investigated. This dissertation applied UV and fluorescent spectroscopy to examine hydrologic and land cover controls on DOM chemistry in streams of 45 catchments in the forested headwaters and a mixed landscape of the Willamette River Basin, Oregon, based on two years of monitoring. This dissertation contributes three major findings. First, freezing of water alters DOM chemistry by preferentially precipitating aromatic DOM. Second, UV and fluorescent spectroscopy was able to discriminate DOM delivered from highly processed, proteinrich deep subsurface sources during dry seasons especially in forested headwater streams of the H. J. Andrews Experimental Forest (HJA), where nitrogen inputs are very low. In addition, fluorescent DOM chemistry differed among watersheds with varying forest management history. Third, although fluorescent DOM in a headwater forested system differed among land use history, fluorescent DOM composition did not vary among streams draining a well-mixed landscape of urban, pasture/hay, forest, and agricultural land cover types in the central Willamette River Basin, where nitrogen inputs to streams are relatively high. Dissolved organic carbon (DOC) concentration decreased and the fluorescent index indicated an increase in terrestrial sources of DOM from small (1st and 2nd order) to large (4th to 6th order) streams. A protein-like DOM component that was detected in the headwater forested study site (HJA) was not detected in stream samples from the middle basin study site. These findings indicate that in-stream respiration, fueled by nutrient additions from agriculture runoff, consumes bioavailable, labile DOM (proteins) preferentially relative to more recalcitrant, terrestrial sources of DOM along water flow paths from headwater streams to major rivers. This study shows the clear applicability of the fluorescent characterization of DOM in identifying hydrologic and landscape controls as well as varying DOM chemistry and functions throughout watershed ecosystems. Close

• 34. [Article] Bull Trout (Salvelinus confluentus) population and habitat surveys in the McKenzie and Middle Fork Willamette Basins, 2000

  DOE/BP-00004093-1

  Citation × Citation Citation Abstract Copy Title: Bull Trout (Salvelinus confluentus) population and habitat surveys in the McKenzie and Middle Fork Willamette Basins, 2000 Author: Taylor, Greg DOE/BP-00004093-1 Title: Bull Trout (Salvelinus confluentus) population and habitat surveys in the McKenzie and Middle Fork Willamette Basins, 2000 Author: Taylor, Greg DOE/BP-00004093-1 Close

• 35. [Article] Watershed stewardship needs assessment policy issues

  Results from a 1999 survey of watershed councils, soil and water conservation districts, and friends groups. Bounding coordinates: West Bounding Coordinate: -123.769586; East Bounding Coordinate: -121.631074; ...

  Citation × Citation Citation Abstract Copy Title: Watershed stewardship needs assessment policy issues Author: Willamette Restoration Initiative Results from a 1999 survey of watershed councils, soil and water conservation districts, and friends groups. Bounding coordinates: West Bounding Coordinate: -123.769586; East Bounding Coordinate: -121.631074; North Bounding Coordinate: 45.941295; South Bounding Coordinate: 43.350360. Title: Watershed stewardship needs assessment policy issues Author: Willamette Restoration Initiative Results from a 1999 survey of watershed councils, soil and water conservation districts, and friends groups. Bounding coordinates: West Bounding Coordinate: -123.769586; East Bounding Coordinate: -121.631074; North Bounding Coordinate: 45.941295; South Bounding Coordinate: 43.350360. Close

• 36. [Article] Effects of harvest and roads on in-stream wood abundance in the Blue River Basin, western Cascades, Oregon

  Despite many studies of large wood in streams, few landscape scale studies have been conducted. Large-scale studies can reveal how the history of forest harvest and road building has influenced wood patterns ...

  Citation × Citation Citation Abstract Copy Title: Effects of harvest and roads on in-stream wood abundance in the Blue River Basin, western Cascades, Oregon Author: Czarnomski, Nicole M. Despite many studies of large wood in streams, few landscape scale studies have been conducted. Large-scale studies can reveal how the history of forest harvest and road building has influenced wood patterns in streams of the Pacific Northwest. This study examined the relationships between wood in streams, timber harvest, and road building at large (>50 km² ) spatial and long (>25 year) temporal scales, based on longitudinal surveys of 25.2 km of stream length in five sub-basins of the Blue River Basin, Cascade Range, Oregon. In-stream wood was surveyed in six sampling sites, ranging from 1.6 km to 14.1 km in length along 2nd to 5th -order channels in public forests. Wood volumes, numbers of pieces of large wood, numbers of accumulations and timing of emplacement were determined at 50-m intervals. Wood volumes and numbers of pieces were expressed per unit of channel area in order to account for variations in channel width. Wood volumes and piece numbers were related to spatial data on harvest and road building using GIS. Analysis of variance (using SAS) tested how wood volumes and piece numbers were related to the presence of a harvest or road unit within 40 m of the stream, sampling site, timing of harvest, distance harvest was from the channel, and effects of natural processes. P-values for pairwise comparisons were adjusted using a Bonfenoni procedure. Distributed patch clearcutting and road construction were concentrated in the 1950's and 1960's in the Lookout Creek basin and 1960's to the 1980's in the Upper Blue River basin. A total of 66% (Cook Creek), 55% (Mack Creek), 53% (Lower Lookout), 37% (McRae Creek and Upper Lookout), and 7% (Quentin Creek) of stream length had harvests and/or roads within 40 m of the stream. Approximately 80% of the wood volume and 85% of the number of large pieces occurred in accumulations. Wood volumes were lower in 5th-order compared to 3rd -order streams. Lower Lookout (the only 5th-order channel) had significantly lower wood volumes (109 m³/ha) than all other locations (200-378 m³/ha, p<O.O5) and significantly lower numbers of large pieces (23 large pieces/ha) compared to all other locations (39 vs. 64 large pieces/ha, p<O.008). All other locations had fairly similar wood volumes and numbers of large pieces For all study sites combined, 50-m stream segments without harvests or roads had significantly higher volume (356 m³/ha) and number of large pieces (57 pieces/ha), than stream segments with harvests or roads within 40 m (80 to 157 m³/ha, p<O.O3; 19 to 39 pieces/ha, p<O.O4). Stream segments without harvests or roads (32 pieces/ha) also had significantly higher number of accumulations compared to stream segments with roads (16 pieces/ha, p<O.004), or compared to stream segments with harvest on one side and roads (16 pieces/ha, p<O.004). Distance a harvest was from the stream and timing of harvest did not appear to affect wood volume or number of large pieces. Harvests and roads were associated with decreases in wood abundance 50 m upstream and 50 m downstream of harvest units and road crossings. The 50-m stream segments immediately upstream (171.8 m³/ha) and downstream (191.6 m³/ha) of a section of stream with harvest and roads had significantly lower volume than the 50-m stream segments without harvest or roads (427.7 m³/ha, p<O. 1). Natural processes such as floods, windthrow, near-stream toppling, and debris flows from the last 50 years had not obscured the effects of harvest and roads on wood volume and number of pieces in stream channels of Lookout Creek and Blue River. The legacy of harvest and road activities was still apparent in in-stream wood patterns up to 50 years later in this site, which consisted of old-growth forest subjected to dispersed patch clearcutting, road construction, and salvage logging conducted in the 1950's to the 1980s. However, harvest, road, and salvage practices on public lands have changed since that period. Therefore, these results should be extrapolated to other sites only with careful consideration of site history. Title: Effects of harvest and roads on in-stream wood abundance in the Blue River Basin, western Cascades, Oregon Author: Czarnomski, Nicole M. Despite many studies of large wood in streams, few landscape scale studies have been conducted. Large-scale studies can reveal how the history of forest harvest and road building has influenced wood patterns in streams of the Pacific Northwest. This study examined the relationships between wood in streams, timber harvest, and road building at large (>50 km² ) spatial and long (>25 year) temporal scales, based on longitudinal surveys of 25.2 km of stream length in five sub-basins of the Blue River Basin, Cascade Range, Oregon. In-stream wood was surveyed in six sampling sites, ranging from 1.6 km to 14.1 km in length along 2nd to 5th -order channels in public forests. Wood volumes, numbers of pieces of large wood, numbers of accumulations and timing of emplacement were determined at 50-m intervals. Wood volumes and numbers of pieces were expressed per unit of channel area in order to account for variations in channel width. Wood volumes and piece numbers were related to spatial data on harvest and road building using GIS. Analysis of variance (using SAS) tested how wood volumes and piece numbers were related to the presence of a harvest or road unit within 40 m of the stream, sampling site, timing of harvest, distance harvest was from the channel, and effects of natural processes. P-values for pairwise comparisons were adjusted using a Bonfenoni procedure. Distributed patch clearcutting and road construction were concentrated in the 1950's and 1960's in the Lookout Creek basin and 1960's to the 1980's in the Upper Blue River basin. A total of 66% (Cook Creek), 55% (Mack Creek), 53% (Lower Lookout), 37% (McRae Creek and Upper Lookout), and 7% (Quentin Creek) of stream length had harvests and/or roads within 40 m of the stream. Approximately 80% of the wood volume and 85% of the number of large pieces occurred in accumulations. Wood volumes were lower in 5th-order compared to 3rd -order streams. Lower Lookout (the only 5th-order channel) had significantly lower wood volumes (109 m³/ha) than all other locations (200-378 m³/ha, p<O.O5) and significantly lower numbers of large pieces (23 large pieces/ha) compared to all other locations (39 vs. 64 large pieces/ha, p<O.008). All other locations had fairly similar wood volumes and numbers of large pieces For all study sites combined, 50-m stream segments without harvests or roads had significantly higher volume (356 m³/ha) and number of large pieces (57 pieces/ha), than stream segments with harvests or roads within 40 m (80 to 157 m³/ha, p<O.O3; 19 to 39 pieces/ha, p<O.O4). Stream segments without harvests or roads (32 pieces/ha) also had significantly higher number of accumulations compared to stream segments with roads (16 pieces/ha, p<O.004), or compared to stream segments with harvest on one side and roads (16 pieces/ha, p<O.004). Distance a harvest was from the stream and timing of harvest did not appear to affect wood volume or number of large pieces. Harvests and roads were associated with decreases in wood abundance 50 m upstream and 50 m downstream of harvest units and road crossings. The 50-m stream segments immediately upstream (171.8 m³/ha) and downstream (191.6 m³/ha) of a section of stream with harvest and roads had significantly lower volume than the 50-m stream segments without harvest or roads (427.7 m³/ha, p<O. 1). Natural processes such as floods, windthrow, near-stream toppling, and debris flows from the last 50 years had not obscured the effects of harvest and roads on wood volume and number of pieces in stream channels of Lookout Creek and Blue River. The legacy of harvest and road activities was still apparent in in-stream wood patterns up to 50 years later in this site, which consisted of old-growth forest subjected to dispersed patch clearcutting, road construction, and salvage logging conducted in the 1950's to the 1980s. However, harvest, road, and salvage practices on public lands have changed since that period. Therefore, these results should be extrapolated to other sites only with careful consideration of site history. Close

• 37. [Article] A comparative analysis of stream response to disturbance in the Pacific Northwest

  Published literature about six Pacific Northwest stream systems was contrasted to provide a regional perspective on channel response to disturbance. This investigation was prompted by a combination of ...

  Citation × Citation Citation Abstract Copy Title: A comparative analysis of stream response to disturbance in the Pacific Northwest Author: Hodgins-Carlson, Terry Anne Published literature about six Pacific Northwest stream systems was contrasted to provide a regional perspective on channel response to disturbance. This investigation was prompted by a combination of recent environmental legislation, mounting social pressures to plan projects at a drainage basin scale, and the difficulty in defining and predicting the response and recovery of a stream channel to land-use management or storm events. Detailed studies of Redwood Creek, CA; the San Lorenzo River, CA; the South Fork Salmon River, ID; the Upper Middle Fork of the Willamette River, OR; the Alsea River System, OR; and Carnation Creek, B.C. were reviewed and contrasted. Differences in channel response to disturbance appear to be the result of the sequence of storms, the interactions between storms and land-use, the processes that deliver sediment to the channel, the available stream power, and the bank stability. Basins with low debris avalanche and earthflow potential, high stream power, and stable stream banks experience only localized and short-lived response to disturbance. On the other hand, basins with frequent debris avalanches or high earthflow potential and unstable banks experience widespread and persistent response. This study concludes that there must be realization and acceptance of the random nature of channel response and recovery following disturbance. Field evaluation, professional judgement, risk assessment, and adaptive management are the most powerful tools available in the prediction of channel response. Title: A comparative analysis of stream response to disturbance in the Pacific Northwest Author: Hodgins-Carlson, Terry Anne Published literature about six Pacific Northwest stream systems was contrasted to provide a regional perspective on channel response to disturbance. This investigation was prompted by a combination of recent environmental legislation, mounting social pressures to plan projects at a drainage basin scale, and the difficulty in defining and predicting the response and recovery of a stream channel to land-use management or storm events. Detailed studies of Redwood Creek, CA; the San Lorenzo River, CA; the South Fork Salmon River, ID; the Upper Middle Fork of the Willamette River, OR; the Alsea River System, OR; and Carnation Creek, B.C. were reviewed and contrasted. Differences in channel response to disturbance appear to be the result of the sequence of storms, the interactions between storms and land-use, the processes that deliver sediment to the channel, the available stream power, and the bank stability. Basins with low debris avalanche and earthflow potential, high stream power, and stable stream banks experience only localized and short-lived response to disturbance. On the other hand, basins with frequent debris avalanches or high earthflow potential and unstable banks experience widespread and persistent response. This study concludes that there must be realization and acceptance of the random nature of channel response and recovery following disturbance. Field evaluation, professional judgement, risk assessment, and adaptive management are the most powerful tools available in the prediction of channel response. Close

• 38. [Article] Statistical summaries of streamflow data in Oregon : Volume 2, annual low and high flow, and instantaneous peak flow

  Statistical summaries of streamfiow data at 358 stream-gaging sites are presented to aid in appraising the hydrology of river basins in Oregon. Records for 36 stream-gaging stations were compiled into ...

  Citation × Citation Citation Abstract Copy Title: Statistical summaries of streamflow data in Oregon : Volume 2, annual low and high flow, and instantaneous peak flow Author: Oregon. Water Resources Dept., Wellman, Roy E, Moffatt, R. L., Gordon, Janice M. Statistical summaries of streamfiow data at 358 stream-gaging sites are presented to aid in appraising the hydrology of river basins in Oregon. Records for 36 stream-gaging stations were compiled into separate periods because of changes in streamflow regulation during the period of data collection. Statistical summaries for the periods before and after regulation are presented for comparison. Title: Statistical summaries of streamflow data in Oregon : Volume 2, annual low and high flow, and instantaneous peak flow Author: Oregon. Water Resources Dept., Wellman, Roy E, Moffatt, R. L., Gordon, Janice M. Statistical summaries of streamfiow data at 358 stream-gaging sites are presented to aid in appraising the hydrology of river basins in Oregon. Records for 36 stream-gaging stations were compiled into separate periods because of changes in streamflow regulation during the period of data collection. Statistical summaries for the periods before and after regulation are presented for comparison. Close

• 39. [Article] Historical changes in anadromous fish habitat in the Upper Grande Ronde River, Oregon, 1941-1990

  The U.S. Bureau of Fisheries (now National Marine Fisheries Service) conducted stream habitat surveys in the Upper Grande Ronde River Basin in 1941. This survey was part of an extensive inventory of stream ...

  Citation × Citation Citation Abstract Copy Title: Historical changes in anadromous fish habitat in the Upper Grande Ronde River, Oregon, 1941-1990 Author: McIntosh, Bruce A. The U.S. Bureau of Fisheries (now National Marine Fisheries Service) conducted stream habitat surveys in the Upper Grande Ronde River Basin in 1941. This survey was part of an extensive inventory of stream habitat conditions for anadromous salmonids (Oncorhynchus spp.) throughout the Columbia River Basin. The survey systematically inventoried 158 km of streams within the 3000 km2 watershed. Stream habitat was degraded from land-use activities (riparian timber harvest, splash dams, stream channelization, livestock grazing, and mining) prior to the 1941 survey. A 1990 resurvey determined how stream habitat conditions had continued to change. The historical survey and the 1990 resurvey inventoried streams according to pool and substrate characteristics. Pools were classified by size and depth criteria, while substrate was divided into size-classes. Losses in total pools/km (> 20m2 area and > 0.5 m depth) ranged from 43 to 83% (mean = 65%, 12.2 to 4.31km), while the loss in large pools/km (> 20m2 and > 1.0 m depth) ranged from 20 to 89% (mean = 68%, 6.2 to 2.0/1cm) for individual streams. The loss of variability in pool frequencies from 1941 to 1990 (total pools/km a2 = 43.9 to 2.8, large pools/km a2 = 23.2 to 3.2) demonstrates that stream channels have become less diverse. Classifying streams by reach types indicated that the decline in pool frequencies was not significantly related to geomorphic constraints. Substrate composition appears to have shifted toward smaller size-classes, with an increase in fine sediments (< 6mm) in the headwaters. Livestock grazing declined 78% (229,000 to 51,000 aum) from 1911 to 1990, while annual timber harvest increased 172% (36 to 98 mmbf) from the pre-survey period (1896-1940) to the post-survey period (1940-1990). Road densities have increased concurrent with timber harvest, currently averaging 4 miles/mile2. Base discharge has increased 51% (18.5 to 28.0 cfs), while there has been a 27% decrease in annual precipitation (22.0" to 16.0") and snowpack (April 1 water equivalent) (15.0" to 10.5") from 1941 to 1990. In an era of presumably improving management (1941-1990), large-scale losses in the fish habitat necessary for the continued viability of resident and anadromous fish populations continued to occur. Title: Historical changes in anadromous fish habitat in the Upper Grande Ronde River, Oregon, 1941-1990 Author: McIntosh, Bruce A. The U.S. Bureau of Fisheries (now National Marine Fisheries Service) conducted stream habitat surveys in the Upper Grande Ronde River Basin in 1941. This survey was part of an extensive inventory of stream habitat conditions for anadromous salmonids (Oncorhynchus spp.) throughout the Columbia River Basin. The survey systematically inventoried 158 km of streams within the 3000 km2 watershed. Stream habitat was degraded from land-use activities (riparian timber harvest, splash dams, stream channelization, livestock grazing, and mining) prior to the 1941 survey. A 1990 resurvey determined how stream habitat conditions had continued to change. The historical survey and the 1990 resurvey inventoried streams according to pool and substrate characteristics. Pools were classified by size and depth criteria, while substrate was divided into size-classes. Losses in total pools/km (> 20m2 area and > 0.5 m depth) ranged from 43 to 83% (mean = 65%, 12.2 to 4.31km), while the loss in large pools/km (> 20m2 and > 1.0 m depth) ranged from 20 to 89% (mean = 68%, 6.2 to 2.0/1cm) for individual streams. The loss of variability in pool frequencies from 1941 to 1990 (total pools/km a2 = 43.9 to 2.8, large pools/km a2 = 23.2 to 3.2) demonstrates that stream channels have become less diverse. Classifying streams by reach types indicated that the decline in pool frequencies was not significantly related to geomorphic constraints. Substrate composition appears to have shifted toward smaller size-classes, with an increase in fine sediments (< 6mm) in the headwaters. Livestock grazing declined 78% (229,000 to 51,000 aum) from 1911 to 1990, while annual timber harvest increased 172% (36 to 98 mmbf) from the pre-survey period (1896-1940) to the post-survey period (1940-1990). Road densities have increased concurrent with timber harvest, currently averaging 4 miles/mile2. Base discharge has increased 51% (18.5 to 28.0 cfs), while there has been a 27% decrease in annual precipitation (22.0" to 16.0") and snowpack (April 1 water equivalent) (15.0" to 10.5") from 1941 to 1990. In an era of presumably improving management (1941-1990), large-scale losses in the fish habitat necessary for the continued viability of resident and anadromous fish populations continued to occur. Close

• 40. [Article] Hydrologic integration of forest roads with stream networks in two basins, western Cascades, Oregon

  This study assessed how logging-access roads may have contributed to observed historical increases in peak discharges associated with small and large logged basins in the western Cascades of Oregon. The ...

  Citation × Citation Citation Abstract Copy Title: Hydrologic integration of forest roads with stream networks in two basins, western Cascades, Oregon Author: Wemple, Beverly C. This study assessed how logging-access roads may have contributed to observed historical increases in peak discharges associated with small and large logged basins in the western Cascades of Oregon. The study was conducted on the Lookout Creek (62km²) and the upper Blue River (118km²) basins. Potential road effects on hydrology were examined using a combination of field surveys and spatial modeling with a geographic information system (GIS). Road networks were similar in both basins with respect to hillslope position, orientation, and stream crossings, but roads in Blue River were constructed one or two decades later than roads in Lookout Creek. A total of 20% (62 km) of the road length was sampled to assess routing of surface flow, using 31 2-km transects stratified by decade of construction and hillslope position. Along each transect, ditches and culvert outlets were examined and this information used to predict the probable routing of water to (1) existing stream channels, (2) newly eroded gullies downslope of culvert outlets, or (3) subsurface flow. Nearly 60% of the surveyed road length appeared to route water directly to stream channels or into gullies. Over time, the length of road connected to stream crossings has decreased, while the length of road discharging runoff that reinfiltrates to subsurface flow has increased, as roads have progressed up hillslopes and onto ridges in Lookout Creek and Blue River. The relatively constant proportion of the road network draining to gullies over time suggests that roads have the potential to become integrated into stream networks, even when constructed on unchannelled hillslope positions. An extended stream network, assumed to exist under storm conditions, was simulated for the basins using a digital elevation model. Although gullies and ditches differ from natural channels, extrapolation of field surveys using the GIS suggested that roads might extend the stream network by as much as 40% during storm events. It is hypothesized that such an effect could decrease the time of concentration of stormflow and contribute to higher peak discharges observed after clearcutting and road construction in these basins. Differences in the magnitude of road effects on peak flow generation may occur among road systems according to hillslope position of roads, road age, soil saturation, geologic substrate, and climate. These differences may explain the range of observed results from paired-basin studies examining road effects on hydrologic response. Title: Hydrologic integration of forest roads with stream networks in two basins, western Cascades, Oregon Author: Wemple, Beverly C. This study assessed how logging-access roads may have contributed to observed historical increases in peak discharges associated with small and large logged basins in the western Cascades of Oregon. The study was conducted on the Lookout Creek (62km²) and the upper Blue River (118km²) basins. Potential road effects on hydrology were examined using a combination of field surveys and spatial modeling with a geographic information system (GIS). Road networks were similar in both basins with respect to hillslope position, orientation, and stream crossings, but roads in Blue River were constructed one or two decades later than roads in Lookout Creek. A total of 20% (62 km) of the road length was sampled to assess routing of surface flow, using 31 2-km transects stratified by decade of construction and hillslope position. Along each transect, ditches and culvert outlets were examined and this information used to predict the probable routing of water to (1) existing stream channels, (2) newly eroded gullies downslope of culvert outlets, or (3) subsurface flow. Nearly 60% of the surveyed road length appeared to route water directly to stream channels or into gullies. Over time, the length of road connected to stream crossings has decreased, while the length of road discharging runoff that reinfiltrates to subsurface flow has increased, as roads have progressed up hillslopes and onto ridges in Lookout Creek and Blue River. The relatively constant proportion of the road network draining to gullies over time suggests that roads have the potential to become integrated into stream networks, even when constructed on unchannelled hillslope positions. An extended stream network, assumed to exist under storm conditions, was simulated for the basins using a digital elevation model. Although gullies and ditches differ from natural channels, extrapolation of field surveys using the GIS suggested that roads might extend the stream network by as much as 40% during storm events. It is hypothesized that such an effect could decrease the time of concentration of stormflow and contribute to higher peak discharges observed after clearcutting and road construction in these basins. Differences in the magnitude of road effects on peak flow generation may occur among road systems according to hillslope position of roads, road age, soil saturation, geologic substrate, and climate. These differences may explain the range of observed results from paired-basin studies examining road effects on hydrologic response. Close