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Accueil du site → Master → Etats Unis → 2000 → Monitoring land-cover change detection in an arid urban environment : A comparison of change detection techniques

West Virginia University (2000)

Monitoring land-cover change detection in an arid urban environment : A comparison of change detection techniques

Almutairi, Abdullah

Titre : Monitoring land-cover change detection in an arid urban environment : A comparison of change detection techniques

Auteur : Almutairi, Abdullah

Université de soutenance : West Virginia University

Grade : Master of Arts in Geography 2000

Résumé
This study compares five change detection techniques to study land cover change associated with the growth of Las Vegas, Nevada, one of the fastest growing areas in the U.S. The data used were three MSS images covering a twenty year period (1972, 1986 and 1992), and one TM image from 1993. The change detection methods used were red band image differencing, principle component analysis, post-classification comparison, change vector analysis, and multi-temporal compositing and classification. Each change detection method was applied to pairs of Landsat MultiSpectral Scanner (MSS) images and a pair of MSS and Thematic Mapper (TM) images. Image normalization for the change vector analysis and image differencing was carried out using a pseudoinvariant feature approach. It was assumed that detecting changes using data from a single sensor type would be preferable to an analysis based on two or more different sensors. However, this study showed that change detection using a combination of TM and MSS produced results comparable to those using only MSS data. It was also found that each of the five methods had their own strengths and weaknesses. Red band image differencing, one of the simplest approaches, successfully differentiated the two major types of changes. Disturbed areas were associated with increased red radiance, and areas of new or more dense green vegetation were associated with decreased red radiance. Principle component analysis gave a much more complex perspective of land use changes, though it requires considerable knowledge of spectral cover types in order to interpret the eigenvector loadings. Post-classification comparisons were found to be intuitive to understand, but complex in the sense that the number of potential land use transitions equals the square of the number of land use classes in the original classifications. Two approaches for the change vector analysis approach were investigated. The first method is the conventional, two band method, while the second one is an adaptation of the hyperspherical direction cosine approach of Pouch and Campagna (1990), which was developed originally for topographic normalization. The conventional approach is conceptually simpler then the hyperspherical approach. On the other hand, the hyperspherical direction cosine method illustrated the spectral pattern of change more clearly. For the multi-temporal composite and classification approach, the best results were obtained using the combined TM and MSS data.

Mots clés : Remote sensing, Geography, Social sciences, Nevada, Applied sciences

Présentation (OATD)

Page publiée le 25 octobre 2013, mise à jour le 6 septembre 2018