Rule Based Classification for Urban Heat Island Mapping

SUMMARY One of the main parameter for urban heat island mapping is the land cover information. Satellite data were used to map the land cover over the study area, CyberJaya. Remotely sensed data were processed using pixel based and object based image processing techniques. Most traditional classification approaches are based exclusively on the digital number of the pixel itself. Thereby only the spectral information is used for the classification. As a result, the use of spectral based classification methods has been repeatedly reported to create confusion among the classes especially on the cloud cover occurred at hilly area always brings the familiar Digital Number (DN) with urban and bare land in the optical remote sensing images. An object-oriented classification is preferred in order to overcome the limitations mentioned above. The technique allows the polygon based classification process. It is based on fuzzy logic, allows the integration of a broad spectrum of different object features, such as spectral values, shape and texture. Sophisticated classification, incorporating contextual and semantic information, can be performed by utilizing not only image objects attributes but also the relationship between networked image objects. The land use classification result was then used to estimate the emissivity values of several features. Land surface temperature of the study area was then computed. Finally, the land surface temperature and the classified land cover theme were then exported to GIS environment for urban heat mapping analysis.