Physical and Environmental Geography Commons^™

Satellite Remote Sensing For Measuring The Urban Forest Of Portland, Oregon, A. Paul Newman

Dissertations and Theses

Digital pattern recognition methods were used to produce two maps of urban vegetation from LANDSAT Thematic Mapper for the City of Portland, Oregon. The image was acquired on July 7, 1991 and the spectral bands used were 2, 4, 5 and a ratio of 3 and 4. The two maps represent vegetation amount and vegetation type.

Due to the extreme heterogeneous nature of the urban environment, these maps were developed using techniques to reduce and manage the amount of spectral variation. This included purging non-vegetated cells from the multispectral image, and then stratifying the image into "spectral subdivisions" using tools …

Evaluation Of Selected Atmospheric Indices For The Prediction Of Thunderstorms At Omaha, Nebraska, Fred Ladehoff

Open Access Master's Theses (through 2010)

This study examines the values of five stability indices (the Showalter Index, the K Index, the Vertical Totals Index, the Cross Totals Index, and the Total Totals Index) for Omaha, Nebraska during the months of March through September, 1964 through 1973. Index means during thunderstorm periods and non-thunderstorm periods should show a distinct difference. Even though indices can be an important tool, it must be accentuated that indices should never be used as the sole factor in the prediction of thunderstorm or non-thunderstorm occurrences. This study shows that even at the highest skill scores, many mistakes would be made in …

Timing And Extent Of Late Quaternary Paleolakes In The Trans-Pecos Closed Basin, West Texas And South-Central New Mexico, David Wilkins, Donald Currey

David E. Wilkins

The Trans-Pecos Closed Basin is a hydrographically closed region covering 20,000 km centered on Salt Basin, 160 km east of El Paso, Texas. Geomorphic and limnetic evidence have been used to identify four major highstands for Lake King during the last glacial maximum (LGM). Additional geomorphic features from a second, recently identified, paleolake, Lake Sacramento, have been found in the Beargrass subbasin, a nested subbasin approximately 75 km northwest of Salt Basin. Radiocarbon ages of the organic material in Lake King sediments date four abrupt climate changes and rapid lacustrine transgressions during the LGM with a quasi-periodicity of 2000 yr. …