Detection of changes in land cover of an area of western Honduras Period 1991 - 2006

Abstract

Having a set of images of several years classified by land cover, having used the same scientific methodology for all of them, does that the information and the changes detected as for increases or decreases of anyone of the classes are homogeneous, comparable and therefore more reliable. The aim of this work was to detect, from the study of four LandSat satellite images of different dates, the main changes in the land cover of a sector of western Honduras, in a period of fifteen years that spanned seven and a half years before and after Hurricane Mitch. The methodology included, from the selection of the images of appropriate characteristics and dates, the pre processing for geometric and radiometric corrections, the delimitation of the study area and collection of relevant information of the zone, obtaining a legend based on the Land Cover Classification System of the FAO-UNEP, conducting a supervised classification of the four images, the verification of results by using field radiometry and statistical techniques, finishing with multitemporal analysis to detect changes.

As main results: compared the reflectance calculated from LandSat imagery with the reflectance measured with a field radiometer; mapping the supervised classification of the years of 1991, 1995, 2003 and 2006; and changes of land cover were quantified before and after Mitch. Important finding was the marked advance of the agricultural frontier at the expense of the decrease of the coverage of forests of the sector, accompanied on the other hand by the recovery of forest, especially of pine, from coverage of shrubs, pastures and bare soil.

DOI: http://dx.doi.org/10.5377/rct.v0i11.1075

Revista Ciencia y Tecnología, No. 11, diciembre 2012 pp 78-109