Land cover change along the Willamette River, Oregon

The Willamette River and its floodplain in northwest Oregon have changed dramatically since European settlement. At one time, the river was a vast complex system of braided channels with a broad floodplain forest; it has now been simplified by channelization and dams, and the forest has been removed to support agricultural and urban expansion. This thesis presents three research manuscripts, each of which uses remote sensing and Geographical Information System methods to capture the dynamic nature of land along the Willamette River. In the first article, the river and its floodplain were mapped at four time periods, ranging from pre-settlement to modern day. The paper reports that the river system has been greatly simplified, and the floodplain has lost much of its original forest. An overlay technique was used to identify potential floodplain restoration sites. The second paper details the creation of a landcover map for the Willamette Valley, which shows that the largest portion of the floodplain is now in agriculture, with a significant amount in a built condition. The third manuscript outlines a methodology for detecting land cover change along the river during a twenty-year period that coincides with the implementation of the Willamette River Greenway, a land use designation designed to restrict riparian land conversion. It shows that regressive change is still occuring along the river, although not at the same rate as outside the greenway. The three papers lay the foundation for a future study to analyze the socioeconomic conditions which promote change

A 10 Years Review and Classification of the Geographic Information Systems Impact Literature (1998-2008)

Our objective in this paper is to review the literature on the impact of geographic information systems (GIS) in governmental and non-governmental organizations by analyzing 53 articles published between 1998 and 2008. The impacts of GIS are categorized in a taxonomy which designates GIS contributions to efficiency, effectiveness and societal well-being. According to this taxonomy, 38 articles are examined in-depth and their results reported. The focus of GIS impact research efforts in terms of research philosophies, methodologies and geographic focus is also presented. We suggest that the appropriate use of theories, concepts and testing of existing GIS evaluation frameworks could serve as building blocks for more rigorous studies on the impact of GIS, including Land Information Systems (LIS) and Spatial Data Infrastructure (SDI)

Landsat-based monitoring of annual wetland change in the main-stem Willamette River floodplain of Oregon, USA from 1972 to 2012

Despite holding substantial ecological value, wetlands in the United States have experienced a significant decline in both area and function over the past century with the majority of freshwater wetland loss attributed to agricultural conversion. Agriculture is the second largest industry in the State of Oregon and the State places substantial emphasis in its land use planning goals on the preservation of agricultural land. Oregon’s Willamette Valley accounts for the majority of agricultural output with 53% of the valley bottom classified as agricultural land. Additionally, the valley houses 70% of the state's population. The valley was once comprised of extensive wet prairies and abundant riparian forests along the Willamette River floodplain, but native ecosystems have been reduced to a fraction of their original distribution since Euro-American settlement in the mid 1800s. The few wetlands that remain are at high risk to loss and degradation from agricultural activity. Following national wetland conservation policies, Oregon has since attempted to monitor and regulate losses due to disturbance and modification of the State's remaining wetlands through a "no-net-loss" policy aiming to decrease wetland losses and replace disturbed wetlands through mitigation. The National Wetlands Inventory (NWI) was designed to produce detailed maps and status reports of the characteristics and extent of the nation's wetlands and help determine the efficacy of no-net-loss policy implementation on the nation’s wetlands. In some cases, the NWI has been found to have low categorical and spatial accuracy and coarse temporal resolution, with some maps over two decades old. Although Landsat satellite imagery was originally found to lack the needed spatial resolution for classification detail and wetness designation that aerial photography provided, Landsat has 40 years of freely available, high quality annual imagery and should be explored for use in annual wetland change detection. Our objectives were to: (1) Quantify and characterize spatial and ecological trends in annual wetland change through gain, loss, and conversion in the Willamette Valley; (2) Evaluate the effect of the no-net-loss federal wetland conservation policy change enacted in 1990 on trends in net wetland area; and (3) Describe a new methodology that reaches back through the over 40-year Landsat archive to map fine scale wetland and related land-use changes from 1972-2012. We used annual Landsat MSS and TM/ETM+ images from 1972 to 2012 to manually interpret loss, gain, and type conversion of wetland area in the two-year inundation floodplain of the Main-Stem Willamette River using TimeSync, Google Earth, and ArcMap. By creating Tasseled Cap Brightness, Greenness, and Wetness indices for MSS data that visually match TM/ETM+ Tasseled Cap images, we were able to construct a complete and consistent annual time series and utilize the entire Landsat archive. Additionally, with an extended time series, we were able to compare trends of annual net change in wetland area before and after the no-net-loss policy established under Section 404 of the Clean Water Act in 1990. We found that wetlands experienced annual loss, gain, and type conversion across the entire study period. Vegetated wetlands (emergent and riparian wetlands) experienced a 314 ha net loss of wetland area across the 40 year study period whereas non-vegetated wetlands (lacustrine and riverine wetlands) experienced a 393 ha net gain. All wetland types combined saw a 79 ha net increase in wetland area across the full study period. The majority of both gain and loss in the study area was attributed to and from agricultural conversion followed by urban land use. Time series analysis of the rate of change of net wetland area was calculated using the Theil-Sen (TS) Slope estimate analysis. For annual change of wetland area before and after 1990 no-net-loss policy implementations, the rate of annual wetland area lost slowed for riparian wetlands and reversed into trends of annual net gain in area of emergent wetlands. The rate of annual net area gained for lacustrine wetlands was slowed post-policy. Accuracy assessment of land use change polygons in the field was only able to capture 12% of our interpretations due to access restrictions associated with private land. In spite of a low sample size (n=45), overall accuracy of land use classification through wetland change polygons was at 80%. This accuracy increased to 91.1% when land use classes were aggregated to either wetland or upland categories, indicating that our methodology was more accurate at distinguishing between general upland and wetland than finer categorical classes

Meander scars : reflections on healing a river

As Europeans settled the Willamette Valley in the 1800s, they began to simplify Oregon's largest river contained wholly within state boarders—the Willamette. The river lost miles of channels from dikes, dams, and development. Some channels vanished under concrete. Others became meander scars, or shallow, dry depression in the land where the river used to wander. Besides being a geological feature, meander scars are reminders of the wounds of progress and our attempts to control the river. Through a series of personal essays, this book reflects on whether something scarred can once again be whole. It explores a simple question with no single answer: How can we heal a river while healing our relationship to it? The book begins with the history of the Willamette, when it was wild and free, and then moves into all the ways we simplified and left it scarred. The story then reflects on what we might value in healing a river—values such as the complexity of the water's many truths; values of memories and stories that hold the history of a landscape before it was degraded; and values even of grief and danger, which bring us closer to places in unexpected ways. The final reach of the book explores the role of restoration in healing the Willamette-whether working to repair the earth compensates for our misdeeds, and whether restoration is a reflexive act in which participant and landscape are both made anew

A Landscape Plan Based on Historical Fire Regimes for a Managed Forest Ecosystem: the Augusta Creek Study

The Augusta Creek project was initiated to establish and integrate landscape and watershed objectives into a landscape plan to guide management activities within a 7600-hectare (19,000-acre) planning area in western Oregon. Primary objectives included the maintenance of native species, ecosystem processes and structures, and long-term ecosystem productivity in a federally managed landscape where substantial acreage was allocated to timber harvest. Landscape and watershed management objectives and prescriptions were based on an interpreted range of natural variability of landscape conditions and disturbance processes. A dendrochronological study characterized fire patterns and regimes over the last 500 years. Changes in landscape conditions throughout the larger surrounding watershed due to human uses (e.g., roads in riparian areas, widespread clearcutting, a major dam, and portions of a designated wilderness and an unroaded area) also were factored into the landscape plan. Landscape prescriptions include an aquatic reserve system comprised of small watersheds distributed throughout the planning area and major valley-bottom corridor reserves that connect the small-watershed reserves. Where timber harvest was allocated, prescriptions derived from interpretations of fire regimes differ in rotation ages (100 to 300 years), green-tree retention levels (15- to 50-percent canopy cover), and spatial patterns of residual trees. General prescriptions for fire management also were based on interpretations of past fire regimes. All these prescriptions were linked to specific blocks of land to provide an efficient transition to site-level planning and project implementation. Landscape and watershed conditions were projected 200 years into the future and compared with conditions that would result from application of standards, guidelines, and assumptions in the Northwest Forest Plan prior to adjustments resulting from watershed analyses. The contrasting prescriptions for aquatic reserves and timber harvest (rotation lengths, green-tree retention levels, and spatial patterns) in these two approaches resulted in strikingly different potential future landscapes. These differences have significant implications for some ecosystem processes and habitats. We view this management approach as a potential post watershed analysis implementation of the Northwest Forest Plan and offer it as an example of how ecosystem management could be applied in a particular landscape by using the results of watershed analysis

Urban and Rural-residential Land Uses: Their Role in Watershed Health and the Rehabilitation of Oregon’s Wild Salmonids

This technical report by the Independent Multidisciplinary Science Team (IMST) is a comprehensive review of how human activities in urban and rural-residential areas can alter aquatic ecosystems and resulting implications for salmonid recovery, with a geographic focus on the state of Oregon. The following topics are considered in the form of science questions, and comprise the major components of this report: The effects of urban and rural-residential development on Oregon’s watersheds and native wild salmonids. Actions that can be used to avoid or mitigate undesirable changes to aquatic ecosystems near developing urban and rural-residential areas. The benefits and pitfalls of salmonid habitat rehabilitation within established urban or rural-residential areas. Suggested research and monitoring focus areas that will facilitate the recovery of salmonid populations affected by development. The fundamental concepts presented in this report should be applicable to most native salmonid populations across the state. IMST encourages managers and policy-makers with interest in a specific species or geographic region to carefully research local ecological conditions, as well as specific life history characteristics of salmonids in the region. Conserving watershed condition and salmonids in the face of increasing development requires consideration of two distinct sets of processes. First are the human social and economic processes that drive patterns in land use change. Second are the ecological processes, altered by land use, that underlie salmonid habitat changes. This report focuses on the latter and summarizes the effects of rural-residential and urban development on native, wild salmonid populations and the watersheds upon which they depend

Environmental assessment: Hartz young stand management project

318 pp. T.17S, R.4E, Section 31; T.17S, R.5E, Section 31; T.18S. R.4E, Sections 1-6, 8-15, 22-24, 26, and 27; T.18S, R.5E, Sections 3-11, 14-23, and 16-30. Captured April 25, 2007.Proposes to harvest timber on approximately 706 acres, including commercial thinning on 622 acres and regeneration harvest on 84 acres, with commercial harvest volume estimated at 11.6 million board feet. Includes construction of 2,050 feet of temporary roads, 7.8 miles of road closures, and approximately 29.3 miles of road maintenance to allow better access to harvest areas and to reduce impact to resources

Evaluating downstream channel changes in response to a small dam removal on the Calapooia River, Oregon with respect to measurement errors and prior aerial photo observed changes

The objective of this study was to evaluate the use of aerial photos as a substitute for multiple-year pre-removal field data to assess the downstream channel changes associated with a small dam removal. The Brownsville Dam, a 2.1 m tall concrete dam on the Calapooia River, Oregon, was removed in 2007. We surveyed cross sections below the dam during the summers prior to (2007) and follow (2008) removal, and we analyzed aerial photos from 1994 to 2006. The field surveys and aerial photos were used to map the low flow channel and bars over 1.3 km downstream from the dam and in an upstream control reach. Three types of measurement error (position error, identification error, and wetted boundary datum error) were assessed for the field surveys and aerial photos in order make the two methods of measurement more comparable. The first year after the dam removal, we observed changes in bar width, wetted width, and wetted width midpoint as large as 17 m ± 3 m immediately below the dam. We inferred that channel changes below the dam after removal were a result of the removal through comparison with pre-dam removal aerial photos, where changes up to 67 m ± 24 m were predominantly far from the dam, and an upstream control, where changes were only as large as 9 m ± 5 m. We conclude with suggestions of best practices for reducing errors, including establishment of permanent monuments for field surveys, taking measurements at similar, well-known discharges, and generating the highest-quality digital aerial photos through source and scanning choices