江西省定南县滑坡形成条件分析

Analysis on the induced factors of landslide in Dingnan County of Jiangxi Province

江西省定南县滑坡较为发育,1990～2002年,全县共发生滑坡283处,其规模一般较小,但造成的损失大。滑坡均由降雨诱发,4～6月份降雨量较大、多暴雨,该段时间滑坡较为多发;除此以外,影响滑坡形成的因素还有地形地貌、岩土类型、地质构造、岩土结构类型、人工切坡等。江西省定南县主要为中低山与丘陵地形,山坡坡度较大;岩土类型主要为岩浆岩、变质岩,岩石较为破碎,残坡积层与强风化层厚度大;断裂构造较为发育;居民大量挖山建房,形成大量的人工高陡边坡;这些因素为滑坡的形成提供了必要条件。

Landslides distribute widely in Dinnan County of Jiangxi Province. From 1990 to 2002, there were 283 landslides took place. The scale of the landslide is currently small, but the losing is large. Most landslides are induced by rainfall. Rainstorm is often happened and the precipitation is large from April to June every year. In these days, a great deal of landslides took place. Besides rainfall, the factors inducing landslide include geomorphy, type of rock and soil mass, geological structure, structural type of rock and soil mass, artificial slope, etc. Medium-low mountain and hill cover the main areas in this county, where has the characteristics of large gradient, main rock type of magmatic rock and metamorphic rock, rock masses are mostly crashed and easy to be weathered, large thickness of eluvial- declivous soils and strongly weathered zone, wide distribution of faults. The residents build houses by digging mountain slopes, thus a number of high and steep artificial slope have been formed. All of these are the reasons of a great deal of landslides having been taken placed in this county.