关键词: 灾害性重力地貌, 南京

Abstract: Nanjing is locateb in the valley floor.plain of the lower reaches of Yangtze River and the west of Ling-Zhen Mountains, along the north of which the Yangtze River flows as an arc from south-west to north-east. There are many hills anb three-grdbe accumulateb terraces in its urban anb suburban areas, the terracevs urface,cut and eroded by flowing water, has formed gully geomorphy There are many hillslibe slopes, terrace slopes and gully slopes in urban and suburban, and many of these slopes range from 15 to 30 degrees, and the fault steep slopes from 60 to 70. The fracture structure of the area developes and breaks bedrocks.Quaternary sediments are loose and its porosity is bigger and The average rain-fall is about 1, 000mm every year. All of these provide advantageous conditions to form calamitious gravity geomorphy, which has happened and caused econo mic losses including breakdown, slide and river bank caving. A lot of facts demostrate that the calamitous gravity geomorphy is formeb by natural factors and the short-term behaivious in human activities. It's essential to focus our attention on the stuby of the calamitous gravity geomorphy and take some necessary measures to prevent according to the local conditions.

Key words: The calamitons gravity geomorphy, Nanjing