The urbanization of the Pearl River Delta (PRD) Economic Zone is progressing rapidly. Environmental-geological problems are the by-product in the process of rapid urbanization and a reflection of disharmony among man, geo-environment and ecosystem in the pan-metropolitan trend. The main environment-geological problems that have wide impacts on the sustainable urbanization include ground deformation in areas of soft soils, siltation of harbors, river courses and mouths and flooding-waterlogging induced by ab...