• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 7
  • Tagged with
  • 8
  • 8
  • 8
  • 8
  • 4
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Technology and meaning in natural resource management : the story-making role of GIS in the CLAMS project

Duncan, Sally 17 November 2004 (has links)
The working hypothesis for this study is that the introduction of GIS technology into the ancient procedures of map-making has changed the map-making context sufficiently to require a revision of the way we think about, learn from, and use maps, specifically in the public involvement process in natural resource management. The assumption that we jointly know what maps mean, and how to use them, has been carried unchallenged into the vastly changed arena of digital, information-dense, and highly technical map-making, courtesy of Geographic Information Systems (GIS). It has remained unchallenged even as the social context for environmental policy-making is undergoing historic upheaval. GIS fundamentally changes how information is viewed, literally, by many different groups, for its maps and databases contain varying levels of uncertainty, multiple embedded assumptions, potentially privileged knowledge, and considerable power as story-makers, along with unintended and unexplored social consequences. GIS maps/databases are used here as the central refractor of ideas about relationships between scientists and lay audiences; between the post-modern understanding of privilege and social change; and ultimately between technology and meaning, where changing expectations about the role of science in natural resource management resonate most profoundly. Key research questions are: (1) How can GIS maps contribute to mutual learning in the natural resource management arena?, and (2) Which consequences of GIS development could change approaches to natural resource management? The exploratory case study used to address these questions examines GIS maps from the Coastal Landscape Analysis and Modeling Study (CLAMS), a landscape-scale bioregional assessment in western Oregon that draws heavily on GIS technology to illustrate ecological and socioeconomic dynamics and interactions. Findings suggest that use of GIS through time may change the realm of designing and structuring decision problems, adjusting it from a largely science-driven exercise in natural resource management to a more collaborative story-making one. While epistemological differences between scientists and lay audiences remain, they can be offset through such collaboration, with concomitant shifts in power structures that could affect a range of conditions including rates of technology diffusion, and management of a broad transition in how natural resources are perceived and utilized. / Graduation date: 2005
2

A portable geographic information system used to develop an integrated facility management support system for a military installation

Kennedy, David R. (David Richard) 20 November 1997 (has links)
The combination of increased training tempo due to military base closures and the reduction in military budgets have placed a severe burden on the infrastructure at many military installations and emphasized the need for an integrated facility management support system. This research involved linking existing facility, environmental, and operational data within an off the shelf portable geographic information system (GIS) to produce an integrated facility management support system. Presently, no known military installations have an integrated facility management support system linking these systems together within a GIS. An unconstrained theoretical model was first developed using a flowchart logic network to design the system. A detailed application model was then developed using Field Notes as an application model portable GIS package, and Camp Rilea, Oregon, as the application model military installation. The application model was then tested on the military installation at Camp Rilea, to validate the theoretical concept behind the system. The testing conducted on the integrated facility management support system demonstrated the potential for improving the efficiency of facility management operations, and assisting in the prevention of carrying capacity threshold violations on military installations. The results of this research allow for possible implementation of an integrated facility management support system at Camp Rilea and other military installations in the State of Oregon, and the U.S. Army at large. / Graduation date: 1998
3

Linking GIS and a surface irrigation model to evaluate regional effects of furrow irrigation strategies

Faux, Russell N. 30 April 1996 (has links)
The shallow aquifer in Northeast Malheur County, Oregon is polluted with Nitrates at concentrations exceeding federal drinking water standards. Efforts to solve the groundwater problems in this area have focused on developing farm management practices that will increase groundwater quality while maintaining agricultural production. Furrow irrigation is the dominant practice for irrigating row crops in this region. One potential way to improve water quality is to increase furrow irrigation performance on a regional scale. In this study a surface irrigation model, SRFR, was linked to a geographic information system (GIS) for the purpose of evaluating alternate furrow irrigation strategies in Malheur County, Oregon. SRFR is a physically based model that simulates water flow and distribution in irrigated furrows. The model accepts the management parameters that influence the outcome of an irrigation and in return provides measures of water application efficiency, amount of deep percolation, amount of surface run-off, and other performance indicators. The GIS, constructed using ARC/INFO software, contains the spatial data required to run SRFR on individual fields in the region. The data for the GIS were acquired using many different sources and techniques in order to meet the input resolution required by the irrigation model. The primary goal of this research was to develop a tool for evaluating irrigation practices on a regional scale, accounting for the diversity of physical circumstances and management practices that occur within a complex of several hundred farms. The particular application of this tool was for control of nitrate pollution of groundwater in the vicinity of Ontario, Oregon. The integrated system was used to estimate a base condition irrigation that is representative of current irrigation practices. The system was then used to assess irrigation performance using three alternative practices: 1) separate management of wheel and nonwheel compacted furrows; 2) use of an automated control system to vary application set times; and 3) cutback irrigation. Although this represents only a limited assessment of the alternatives that might be considered for the study area, preliminary results suggest that under certain field conditions irrigation efficiency can potentially improve more then 20% over the base condition using alternate strategies. The system demonstrated tremendous potential for identifying trends and variability in system performance in the region. / Graduation date: 1997
4

Using remote sensing, in situ observations, and geographic information systems to map benthic habitats at Heceta Bank, Oregon

Whitmire, Curt E. 08 January 2003 (has links)
Dramatic declines in many species of demersal fishes off the West Coast have resulted in the designation of nine commercially important species as being overfished. While the causes of those declines are not clearly understood, the fact remains that a paucity of life history and abundance data exists for many demersal species, also known as groundfish. Due to this uncertainty, only 21 of the 82 species of groundfish managed under the Groundfish Fishery Management Plan of the Pacific Fishery Management Council (PFMC) have been fully assessed. One challenge in designing a systematic survey of groundfish resources is that many species associate with heterogeneous substrate of varying relief. In many areas, the rugosity of the substrata precludes sampling by conventional techniques (e.g. bottom trawl gear). This has stimulated research that characterizes fish-habitat associations for use in design of new survey methodology. Using a combination of remote sensing, in situ observations, and spatial analytical techniques, four benthic habitat classes were mapped for a large rocky bank off the central Oregon coast known as Heceta Bank. Observational data from human-occupied submersible and remotely operated vehicle dives in the late 1980s, 2000 and 2001 were used to establish habitat classes with specific substrate characteristics that have been statistically shown to correlate with demersal fish distributions. The observational habitat data was then extrapolated over the extent of a multibeam sonar survey conducted in 1998 using quantitative parameters derived from high-resolution bathymetric and backscatter imagery of the seafloor. The resultant map predicts the locations of four habitat classes: Ridge-Gully, High-Relief Rock (boulders, cobbles), Unconsolidated Sediment 1 (muds), and Unconsolidated Sediment 2 (sands). The main utility of the habitat map developed as part of the current study is that it provides a context for analyses of a variety of spatial data. For instance, habitat data provides one additional spatial component besides depth and latitude that can be used to stratify catch per unit effort data from surveys and commercial logbooks. Also, essential fish habitat for many demersal species can now be identified in more detail. Finally, habitat data like those presented here can aid in the design of marine reserves and protected areas by providing a context for spatial analyses of data of ecological importance. / Graduation date: 2003
5

Little houses on the prairie : a predictive model of French-Canadian settlement in Oregon's Willamette Valley

Kinoshita, Jun R. 09 July 2004 (has links)
Using GIS, this study creates a predictive model of a distinct population of French-Canadian settlers, highlighting shared environmental characteristics of known sites that may have factored into their decision-making process as they chose locations for their farmsteads. While traditional historic and archaeological research has been conducted on French Prairie, the advent of GIS and readily available data sets facilitated this first multivariate, statistical, predictive model of French-Canadian settlement. This study explored theoretical and logistical issues of predictive modeling and determined that this population may be uniquely suited to predictive modeling. Here, however, substantiating a previous settlement pattern was problematic and the variables used produced a weak predictive model. One by-product of this research was the digitalization, rectification and analysis of 1852 GLO maps of the French Prairie during the development of the "known sites" data theme. As an initial attempt at modeling, this study points to the need for ongoing archeological testing and modeling efforts as development on and around French Prairie threatens archaeological resources. The study suggests other environmental and social variables for further testing. / Graduation date: 2005
6

A cooperative effort to track Humboldt squid invasions in Oregon

Chesney, Tanya A. 04 September 2012 (has links)
Interannual variability of Humboldt squid (Dosidicus gigas) occurrence in the northern California Current System is largely unknown. In Oregon, the distribution of this versatile predator and what is influencing their range expansion from Mexico is poorly understood due to the recent nature of their "invasion" and a lack of monitoring. Humboldt squid are large predators that have the potential to affect ecosystem structure and fisheries because of their high-energy demands and ability to exploit a variety of oceanographic conditions and prey sources. Developing baseline distribution information is a critical first step to assess their potential ecological, social, and economic impacts, and to develop models to predict future range expansion. This study has two main objectives: (1) to document where and when Humboldt squid have been present in Oregon through cooperative fisheries research, and (2) to correlate the sightings with oceanographic conditions using a geographic information system (GIS) and species distribution modeling (SDM). I conducted 54 interviews with local fishermen and aggregated their squid sightings with available fishery-independent survey and fishery-dependent observer data from the National Marine Fisheries Service. I compiled a total of 339 Humboldt squid sightings, reported for the years 2002-2011 from the Oregon coast to 131�� west longitude. Correlation analyses were performed for Humboldt squid sightings and sea surface temperature (SST), chlorophyll a content (chla), sea surface height anomalies (SSH), dissolved oxygen at 30 m depth (30 m DO), and sea surface salinity (SSS) using a GIS, nonparametric multiplicative regression (NPMR) habitat modeling, and maximum entropy modeling (Maxent). Results indicate that oceanographic conditions have the potential to influence Humboldt squid occurrence, and in Oregon, sightings vary temporally and spatially. Combining the sightings from fishermen and scientific surveys greatly enhanced the spatial extent of the data. Humboldt squid were most frequently observed between 124.4��W and 125��W in proximity to the shelf-break at the 200 m isobath, with peak sightings (116) recorded in 2009 and the fewest (6) reported in 2003 and 2011. The highest occurrence of Humboldt squid were observed at a SST of 10.5-13.0��C, 0.26-3.0 mg m����� chla content, -4.0-1.0 m SSH anomalies, 32.2-32.8 psu SSS, and at 3-4.5 ml L����� and 6-7 ml L����� 30 m depth DO. Maps of estimated likelihood of occurrence generated by NPMR were consistent with overlayed observations from fishermen, which were not used in the model because they were limited to presence-only information. An interdisciplinary approach that incorporates cooperative fisheries research and ecosystem-based management is necessary for monitoring Humboldt squid in Oregon. Traditional methods are insufficient because Humboldt squid are data-poor, highly migratory, and are main predators of many commercially important fisheries in Oregon. Based on my findings, sightings recorded by fishermen covered a much larger area over a longer time frame than the scientific survey and observer data, and excluding their knowledge would have led to a different interpretation of Humboldt squid distribution and environmental tolerances. Although there is uncertainty in the data from potential map bias or misidentification of smaller Humboldt squid, incorporating sightings from fishermen with traditional fisheries research increases the quantity and quality of information. Cooperative monitoring for Humboldt squid could include training in species identification and sea condition reporting in logbooks. Future "invasions" are likely, and more eyes on the water will improve our understanding of the behavior and impacts of Humboldt squid on coastal resources. / Graduation date: 2013
7

An Assessment of the Impacts of Climate Change on the Upper Clackamas River Basin with a Distributed Hydrologic Model

Graves, David 11 August 2005 (has links)
The Pacific Northwest is dependent on seasonal snowmelt for water resources that support a significant portion of its economy. Increased temperatures resulting from higher concentrations of atmospheric greenhouse gases may cause disruptions to these resources because of reductions in the annual snowpack and variations of the timing of snowmelt. This study reconstructs and applies a GIS-based distributed hydrologic model at a monthly scale to assess the effects of future climate change on runoff from the Upper Clackamas River Basin (located near Portland, Oregon). Historic flow data and snow measurements are used to calibrate and test the perfonnance of the hydro logic model for a contemporary period (1971-2000), and the model is run for two future scenarios (2010-2039 and 2070-2099) using IS92 climate change scenarios from two global climate circulation models (Hadley and Canadian Centre for Climate) as inputs. The results forecast that mean peak snowpack in the study area will drop dramatically (36% to 49% by 2010-2039, and 83% to 88% by 2070-2099), resulting in earlier runoff and diminished spring and summer flows. Increases to mean winter runoff by by the 2070-2099 period vary from moderate (13.7%) to large (46.4%), depending on the changes to precipitation forecasted by the global climate circulation models. These results are similar to those of other studies in areas dependent on snowpack for seasonal runoff, but the reductions to snowpack are more severe in this study than similar studies for the entire Columbia Basin, presumably because the elevations of much of the Upper Clackamas Basin are near the current mid-winter snow line.
8

Keying forest stream protection to aquatic ecosystem values in multi-ownership watersheds

Pickard, Brian R. 15 March 2013 (has links)
Forested lands of western Oregon provide aquatic habitat for many fish and riparian dependent species, including a wide variety of salmon species. Current policies set riparian protections using fixed buffers on streams for federal and private lands based on stream type or size. These buffers can create a series of disjointed riparian protections, as federal lands require buffers that are much larger than private lands. In addition, the fixed buffer approach is neither flexible nor tailored to aquatic ecosystem values. This thesis presents a framework for comprehensively assessing stream networks using site specific watershed features and then suggests riparian conservation strategies that key stream and riparian protection to aquatic ecosystem values. Seven study watersheds were used in this analysis, totaling over 2.5 million acres of forested lands in western Oregon. Employing a set of geospatial tools, called NetMap, streams in each watershed were classified into higher and lower priorities using criteria of intrinsic potential, erosion/debris flow susceptibility, and thermal loading potential. Results demonstrated the inherent variability within and among watersheds based on the geomorphic and ecological processes determined important for selected salmon species. Within each watershed, both federal and non-federal lands had many miles of higher priority fish-bearing and non-fish bearing streams, suggesting the need for comprehensive, holistic watershed conservation strategies. Based on the partitioning of streams into higher and lower priorities, an alternative riparian conservation strategy was then modeled for federal lands that allocate protection on the basis of the ecological context of a stream segment’s potential and particular location while still meeting federal aquatic conservation goals and objectives. Possible increases to the land base for long-term timber production were then identified if this strategy were applied to federal Matrix lands. Results demonstrated that 8-30 percent of the current riparian buffers could be reallocated to the land base for long-term timber production. An additional 26-45 percent of current buffers could be managed simultaneously for both timber production and aquatic ecosystem goals. Results also provided a framework for targeting of conservation and restoration efforts towards higher priority streams within each watershed. As many of the most ecologically important streams were located on non-federal lands, riparian conservation policies focused on streams classified as higher priority on those lands may be needed to protect aquatic species and their environments. / Graduation date: 2013

Page generated in 0.1257 seconds