Landscape dynamics of a coastal lagoonal system : southern Sonora, Mexico /
The increasing pressure to develop coastal areas has prompted the need to understand how natural and anthropogenic changes influence the conditions of coastal ecosystems on a broad scale. Historical aerial photography, GIS, and landscape metrics were used to identify and quantify the rates and patte...
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| Format: | Thesis Book |
| Language: | English |
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[Place of publication not identified] :
[publisher not identified] ;
2003.
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| Subjects: | |
| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=765867241&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | The increasing pressure to develop coastal areas has prompted the need to understand how natural and anthropogenic changes influence the conditions of coastal ecosystems on a broad scale. Historical aerial photography, GIS, and landscape metrics were used to identify and quantify the rates and patterns of landscape change between 1968 and 1994 for a 40,000 ha study area known as the Yavaros-Moroncarit lagoonal system in southern Sonora, Mexico. The changes in landscape pattern were associated with concentrations of pollutants (e.g., nutrients, organic matter, organochlorine pesticides, and heavy metals) in water and sediments of the lagoons throughout the study period. Results in changes of land use/land cover indicate that relative large gains in mangrove/forested wetlands (117% in cover area and 113% in mean patch size) and mixed urban land (67% in cover area and 54% in mean patch size) occurred during the study period. Shrub and brush rangeland loss (25% in cover) resulted from gains in agricultural land and mixed barren land. Changes in the land cover proportion of agricultural land, mixed urban land, aquaculture land, and livestock farming have a direct impact on the concentration of pollutants entering the lagoons. However, not all the effects on the ecological conditions in the coastal lagoons can be explained or measured via alteration of land use/land cover proportion. High levels of organic pollution and organochlorine pesticides in the water and sediments of Yavaros and Moroncarit lagoons represent the cumulative effects of the continuous accumulation of pollutants over a period of 25 years and the effects of multiple land uses. |
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| Item Description: | Vita. "Major Subject: Geography". |
| Physical Description: | xiii, 133 leaves : illustrations, maps ; 28 cm. Issued also on microfiche from University Microfilm Inc. |
| Bibliography: | Includes bibliographical references (leaves 113-130). |