Abstract:
Human settlement expansion is one of the most pervasive
forms of land cover change in the Gauteng province of South
Africa. A method for detecting new settlement developments in
areas that are typically covered by natural vegetation using 500 m
MODIS time-series satellite data is proposed. The method is a per
pixel change alarm that uses the temporal autocorrelation to infer
a change index which yields a change or no-change decision after
thresholding. Simulated change data was generated and used to
determine a threshold during an off-line optimization phase. After
optimization the method was evaluated on examples of known land
cover change in the study area and experimental results indicate a
92% change detection accuracy with a 15% false alarm rate. The
method shows good performance when compared to a traditional
NDVI differencing method that achieved a 75% change detection
accuracy with a 24% false alarm rate for the same study area.
