Landscape changes in a coastal lagoon system, Jalisco, Mexico: Implications for Barra de Navidad lagoon.

摘要

Changes in land cover and land use patterns in the Barra de Navidad coastal lagoon system in Jalisco, Mexico were assessed using Landsat imagery, GIS and landscape metrics. Two sub-images from 1985 (Landsat TM) and 2000 (Landsat ETM+) were used to evaluate changes in six categories: lagoon, agriculture, urban/tourist, tropical dry forest, mangrove and bare substratum. Fieldwork was undertaken to ground truth a supervised classification of the sub-images. Spatial changes in each category were evaluated using a transition matrix.; Results show that urban and tourist areas expanded between 1985 and 2000, mostly at the expense of forested and bare land. Mangroves showed a large relative decrease in area and experienced fragmentation, particularly on the lagoon borders. These changes have had direct effects on Barra de Navidad lagoon, resulting in increased sedimentation and delta progradation. Further study of the biophysical condition of the lagoon is needed to fully assess the impacts of landscape modifications.