Landsat digital enhancements for change detection in urban environments

Comparison of Landsat digital classifications from two dates has met with limited success for change detection in urban environments. The capabilities of digital enhancements for displaying change were therefore investigated as an alternative procedure for this task. Three different color enhancements, an overlay of band 5, ratios of bands 5 and 7, and a vegetation index, were generated using 1974 and 1978 Landsat data of Hamilton, Ontario. The ratios only emphasize major changes. The band 5 overlay shows change most clearly, but the vegetation index enhancement is almost as good and in addition to showing change also emphasizes the urban boundary and the major road network. It is suggested that change enhancements could be used effectively by agencies responsible for monitoring urban development over large areas.