12,280 research outputs found

    Cost effectiveness of conventional versus LANDSAT use data for hydrologic modeling

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    Six case studies were analyzed to investigate the cost effectiveness of using land use data obtained from LANDSAT as opposed to conventionally obtained data. A procedure was developed to determine the relative effectiveness of the two alternative means of acquiring data for hydrological modelling. The cost of conventionally acquired data ranged between 3,000and3,000 and 16,000 for the six test basins. Information based on LANDSAT imagery cost between 2,000and2,000 and 5,000. Results of the effectiveness analysis shows the differences between the two methods are insignificant. From the cost comparison and the act that each method, conventional and LANDSAT, is shown to be equally effective in developing land use data for hydrologic studies, the cost effectiveness of the conventional or LANDSAT method is found to be a function of basin size for the six test watersheds analyzed. The LANDSAT approach is cost effective for areas containing more than 10 square miles

    Hydrologic Properties of Subarctic Organic Soils

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    Completion Report for U. S. Forest Service Institute of Northern Forestry Cooperative Agreement No. 16 USC 581; 581a-581iThe need for understanding the natural system and how it responds to various stresses is important; this is especially so in an environment where the climate not only sustains permafrost, but develops massive seasonal frost as well. Consequently, the role of the shallow surface organic layer is also quite important. Since a slight change in the soil thermal regime may bring about a phase change in the water or ice, therefore, the system response to surface alterations such as burning can be quite severe. The need for a better understanding of the behavior and properties of the organic layer is, therefore, accentuated. The central theme of this study was the examination of the hydrologic and hydraulic properties of subarctic organic soils. Summarized in this paper are the results of three aspects of subarctic organic soil examinations conducted during the duration of the project. First, a field site was set up in Washington Creek with the major emphasis on measuring numerous variables of that soil system during the summer. The greatest variations in moisture content occur in the thick organic soils that exist at this site. Our major emphasis was to study the soil moisture levels in these soils. This topic is covered in the first major section, including associated laboratory studies. Those laboratory studies include investigations of several hydraulic and hydrologic properties of taiga organic and mineral soils. Second, some field data on organic moisture levels was collected at the site of prescribed burns in Washington Creek to ascertain the sustainability of fires as a function of moisture levels. This portion of the study is described under the second major heading. The last element of this study was a continued application of the two-dimensional flow model that was developed in an earlier study funded by the U. S. Forest Service, Institute of Northern Forestry, and reported by Kane, Luthin, and Taylor (1975a). Many of the results and concepts gathered in the field work were integrated into the modeling effort, which is aimed at producing better estimates of the hydrologic effects of surface disturbances in the black spruce taiga subarctic ecosystem. This knowledge should also contribute to better fire management decisions of the same system.The work upon which this report is based was made possible by a cooperative aid agreement funded by the U. S. Forest Service, Institute of Northern Forestry, Fairbanks, Alaska. Contribution to this study was also made by Ohio State University

    Heat and Mass Transfer in Cold Regions Soils

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    The work upon which this report is based was made possible by a cooperative aid agreement between the U.S. Forest Service, Institute of Northern Forestry, Fairbanks, Alaska, and the Institute of Water Resources, University of Alaska. Contributions to this study were also made by the University of California at Davis and Ohio State University. The collection of winter data on pore pressures was made possible by a separate grant by the Office of Water Research and Technology (project A-053 ALAS)

    Field evaluation of tile drain filters in a humid region soil

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65482/1/j.1532-5415.2002.50301.x.pd

    Self‐Reported Periodontal Disease: Validation in an Epidemiological Survey

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141948/1/jper1407.pd

    Periodontal disease: associations with diabetes, glycemic control and complications

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73645/1/j.1601-0825.2008.01442.x.pd
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