鄂西北中部地区滑坡孕灾模式分析

Landslide pregnancy pattern of central area in northwest Hubei

鄂西北地区滑坡地质灾害发育丰富。根据滑坡分布发育特征,选取3个非连续变量和10个连续变量,从不同角度揭示鄂西北地区滑坡孕灾模式。基于3个非连续变量的统计分析,识别出四大类孕灾模式为:孕灾模式A(碎石土+志留系碎屑岩)、孕灾模式B(碎石土+武当群片岩)、孕灾模式C(岩质+顺向坡)、孕灾模式D(岩质+顺向斜交坡)。基于10个连续变量的敏感性分析,识别孕灾模式,结果表明:滑坡发育前缘高程主要集中在260~455 m高程段,且多为体积1.6~2.8×10~4m^3的小型滑坡,剖面上具有整体坡度14.4°~43.2°的特点,发育岩层倾角16°~28°。综合连续变量与非连续变量,获得区内滑坡的12类典型孕灾模式,为鄂西北地区滑坡区域孕灾机理研究提供参考。

The landslide geological hazards happen frequently in northwest Hubei Province. According to the characteristics of landslide distribution and development,3 discontinuous variables and 10 continuous variables are selected to reveal the landslide pregnancy mechanism in northwest Hubei Province. Based on the statistical analysis of three discontinuous variables,four types of pregnancy patterns are identified as： pregnancy pattern A（ soil ＋ bedrock（ Silurian sandstone））,pregnancy pattern B（ soil ＋ bedrock（ Wudang schist））,pregnancy pattern C（ rock ＋ consequent slope）,and pregnancy pattern D（ rock ＋ consequent oblique-cross slope）.Based on the sensitivity analysis of 10 continuous variables,identification of disaster development pattern is conducted,the results of which show that the front elevation of the landslide is mainly concentrated in the 260 ~ 455 m elevation section,and most of them are small landslides with the volume of 1. 6 × 10~4~2. 8 × 10~4 m^3,whose profile slope is 14. 4° ~ 43. 2°,and the dip angle of strata is 16° ~ 28°. Combined with continuous variables and discontinuous variables,12 typical pregnancy pattern in the region are obtained,which provides a reference for the study on regional landslide pregnancy mechanism in Northwest Hubei.