Urban Environmental Geological Problems

Environmental geological problems in 200 large or medium-sized cities in China are discussed heie.The total city number in China is 640(1995).Statistics shows that more than SO cities are under threat and influence of active faults;22 cities have conditions of liquefaction; since the middle of the next century, coastal cities such as Shanghai,Tianjin,Ningbo,Guangchow would firstly face the threats of crustal subsidence and rise of the sea level; ground fissure, as a special kind of urban geological hazard, has done huge damages to civil buildings and engineering in Xi&s;an, Datong,Handan and Yanchow; 70 cities, including those in the upper or the middle reaches of the Yangtze River or the Loess Plateau such as Chongqing and Lanchow.are in dangers of landslide and debris flow; ground subsidence is found in more than SO cities due to excessive groundwater abstraction, and in some cities as Shanghai, Tianjin and Xi&s;an, each of the subsidence amount has exceeded 2000mm; the number of cities effectd by collapse event is increasing gradually, more than 40 cities are lying in karst regions. All of above are prominent hazardous environmental geological problems in urbanization development in China.