6ChangeDetectionandTimeSerieLectureNotes

6ChangeDetectionandTimeSerieLectureNotes - 1 GISc 4037 Dr....

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GISc 4037 Dr. Charles Roberts Unit 6 - Global Change/Time Series/Change Detection “Urbanization in the developing countries must now be recognized as a massive and irreversible phenomenon that demands the attention of LDC governments and donors in the 1990's and beyond,” -Office of Housing and Urban Programs, AID Southeast Florida has been the fastest growing region in the nation for over two decades. But rapid urban growth in metropolitan areas is a global phenomena. International surveys suggest that urban growth in Lesser Developed Countries (LDC’s) in the next thirty years will be ten times the growth experienced in the last thirty years (OHUP, 1988). Globally, urban populations will go from 34 percent to 58 percent of the total population by the year 2025. The United Nations surveys suggest that the number of cities with a population of over five million people went from 10 to 43 by the year 2000. Metropolitan governments are hard pressed to deal with todays issues, and are not in a position to expand services to accomodate the magnitude of growth projected for metropolitan areas. In particular, the ability of mapping agencies to keep up with change has declined precipitously. The decline has been evident in Britain for a number of years, and the decline is now evident as well in the United States. For example, the census bureau used to go door to door to collect data and now it only visits 2% of all households, relies on mail surveys for its estimate of 98% of the population. In south Florida, a two year old map is vastly out of date. Satellite imagery is increasingly available at lower and lower costs, and at higher resolutions. -Landsat MSS data is available for $600 a scene, and increasingly, can be found at various sites for free. In many LDC’s the newest maps available are from the 1970s. Consider the case of St. Vincent Island. The newest Ordinance Survey map produced for the Saint Vincent government was 1983. It shows forest cover. However more current information can be gathered from 1987 satellite imagery which cost $200 for a 75 mile by 75 mile area. -State agencies are beginning to acquire imagery on an annual basis, and they are required by law to make the imagery available to researchers for little or no cost. In many cases, DOQQs are produced every 5 years and made available to researchers through state GIS clearinghouses. Thus, for a limited cost and some image processing time, a city can update its land-use map whenever it can afford the staff and dollars. It is also possible to monitor rural environmental change as well. Digital image analysis is a powerful tool for environmental managers and land-use planners. While the advent of DOQ’s have caused urban and environmental planners to jump on the remote sensing bandwagon, few have any training in the use of imagery, and fewer yet have any image processing training. Definitions: Global Change, Change Detection, Time Series analysis
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This note was uploaded on 12/21/2010 for the course GIS 4037c taught by Professor Roberts during the Fall '10 term at FAU.

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6ChangeDetectionandTimeSerieLectureNotes - 1 GISc 4037 Dr....

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