Researchers analyzed how land use changed in the Pearl River Delta from 1990 to 2005. They used a method called spatial autocorrelation analysis to see if there were any patterns in how land was used. The overall pattern of land use was found to be random, but when looking at specific areas and time periods, differences were seen. This suggests that some parts of the region developed more than others. The study shows that spatial autocorrelation analysis is a useful tool for understanding and predicting changes in land use.