Habitat change on Horn Island,Mississippi, 1940-2010, determined from textural features in panchromatic vertical aerial imagery |
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Authors: | Guy W Jeter Jr |
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Institution: | 1. Department of Geography and Geology, University of Southern Mississippi, Long Beach, MS, USA;2. Gulf Coast Geospatial Center, University of Southern Mississippi, Long Beach, MS, USA |
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Abstract: | Habitat-type land cover on Horn Island, Mississippi, northern Gulf of Mexico, was estimated for the years 1940 and 2010 using a combination of panchromatic imagery and 2010 ground survey data. A grey-level co-occurrence matrix was applied to compute reflectance coefficient of variation (CV) and texture indices. The relationships of 2010 CV ranges with known habitat types defined training regions of interest in the 1940 imagery as a substitute for 1940 ground data. Texture indices contrast, correlation, energy and entropy then served as input bands for maximum likelihood classifications which produced 1940 and 2010 habitat maps. Analysis determined that wetter habitats on Horn expanded linearly over the seven-decade period. This is attributed to constraints on sediment supply and the impacts of severe storms which led to decreases in soil depth to the water table. If this trend continues, marsh habitat will cover 31% of Horn Island’s land area by 2050. |
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Keywords: | Barrier island black-and-white photography GLCM spatial statistics image texture |
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