A new landscape ecology mapping scheme for coastal environments: Galveston Island, Texas

Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to digital@library.tamu.edu, referencing the URI of the item.Includes bibliographical references: p. 107-112.Issued also on microfiche from Lange Micrographics.Increasing urban development on barrier islands has driven interest in the environmental change of barrier islands. Whereas other research has focused on individual elements of this environmental change, this thesis applies the concepts of landscape ecology to understand the complete picture of the changing environment of a barrier island. Mapping is fundamental to detecting and monitoring change. Currently no mapping scheme can effectively integrate geomorphological and ecological mapping of the landscape. This research combines the fundamental concepts of landscape ecology and geomorphological mapping to develop a landscape ecological mapping methodology. The mapping scheme has been developed to understand the landscape change of Galveston Island, Texas from 1980 to 1995. Using a geographic information system (GIS), aerial photograph maps were created and classified with a level I Anderson land use / land cover classification, and then were reclassified using the patch-matrix- corridor model of landscape ecology. These maps provide a temporal-based, spatial sununary of landscape change. Comparing these maps from several time periods highlights areas and patterns of change. From 1980 to 1995, Galveston Island experienced a 5% increase in urban area so that it occupies nearly the same total area as the nonforested wetland matrix of Galveston Island. This increased urbanization perforates the non-forested wetland with patches of development and even isolates portions of the salt marsh and wind tidal flat corridors at the margins of the island. The urban expansion has taken place primarily at the expense of salt marsh which experienced a loss of 50 million square feet over the last 15 years. Additionally, this encroachment by urban development has changed the shape of the salt marsh patches. According to an area-to-perimeter comparison, salt marsh areas became thinner and more convoluted in shape from 1980 to 1995. This research shows that land use / land cover classification systems provide a useful prerequisite to landscape ecological mapping. However, the land use / land cover and landscape ecological classification systems should not be mutually exclusive. Each classification system focuses on different aspects of the landscape, and when used together, they provide a powerful tool for land management