山西地堑系地震重力地貌发育及其与水土流失的关系

Coseismic Gravity Landforms and Soil Erosion in the Shanxi Graben System

研究了山西地堑系 1038 年定襄地震、1303 年洪洞地震和 1695 年临汾地震中形成的大量地震重力地貌。这些重力地貌具有成群分布,同时性的特点,并有在非地震条件下难于发生的特殊滑坡现象。地震重力过程作为一种土壤侵蚀的方式,具有分布集中,强度大,历时短,难防范,破坏性大的特点,同时,地震重力地貌过程的堆积物进入河流系统,增强了水流的侵蚀能力。

The Shanxi Graben System is composed of a series of basins,which arranged in a s shaped curve over a distance of 1 200 km from the north to the south.Since 231 AD,twenty earthquakes of a magnitude equal to or larger than 6 have occurred,including one of M=8,five of M=7~7.9,and 14 of M=6~6.9.According to the Chinese historical records,these earthquakes have induced a lot of landslides.The coseismic landslides of Dingxiang(M=7,in 1038),Hongdong(M=8,in 1303)and Linfen(M=8,in 1695)earthquakes are studied here.According to Lichen measurements,the 75%~85% landslides are synchronous.The coseismic landsliding is a way of soil erosion in the Shanxi Graben System.The deposits of landsliding also intensify the water erosion along rivers.