陕西省特大型滑坡空间分布规律与类型划分

特大型滑坡空间分布规律及其类型划分是研究其形成机理、致灾模式与风险减缓对策的重要基础。通过遥感解译、野外调查与解剖勘查等手段，查明陕西省特大型滑坡空间上具有明显的分布规律:在地貌上主要分布于关中盆地黄土塬边44处，其次是黄土梁峁、丘陵区22处，秦岭北坡6处，汉中盆地中低山区6处；在构造单元上分布于包括秦岭北坡断裂带在内的关中断陷盆地72处，汉中断陷盆地6处；在斜坡结构类型上，主要分布于黄土+泥岩型斜坡41处，其次为黄土+基岩型斜坡11处、黄土+红黏土型斜坡9处。特大型滑坡在空间分布上受活动断裂、地貌单元与斜坡结构类型的控制，不同区域发育特大型滑坡类型不同，特大型滑坡类型划分为宝鸡黄土塬边黄土—泥岩顺层型、灞桥白鹿塬边黄土—红黏土逆层型、蓝田横岭地区黄土—红黏土接触面型、关中盆地渭北地区黄土—基岩接触面型、陇县北部及韩城黄土梁峁区岩土混合型以及秦岭北坡与陕南“勉略宁”地区的堆积层型、顺向或块状岩质型滑坡等。

Spatial Distribution and Type Classification of Super Large Landslides in Shaanxi Province

The spatial distribution and type classification of super large landslides can provide the basis for research on the formation mechanism, disaster-causing mode and risk mitigation strategy of super large landslides in Shaanxi Province. For seeking the spatial distribution regular and reasonable type classification of super large landslides in Shaanxi province, the statistics and analysis for the number and distribution according to physiognomy, tectonic unit and structure type of slopes were made based on remote sensing interpretation, field survey and investigation. The statistics result indicates that according to the physiognomy, 44 super large landslides are along the margin of loess tablelands, 22 ones lie in the loess hill ridge areas, 6 ones are locate in the north of Qinling Mountains, and 6 ones scatter in the mountain areas with middle and low heights in the west of Hanzhong sinking basin;on the basis of the tectonic units, 72 ones lie in the Guanzhong sinking basin including the northern Qinling fault belt, where the active faults develop, and 6 ones are in the Hanzhong sinking basin; in the light of the structure types of slopes, 41 ones develop in the slopes with structure of loess-mudstone, as well as 11 ones in the slopes with structure of loess-bedrock and 9 ones in the slopes with structure of loess-red clay. It proves that the spatial distribution regular of super large landslides in Shaanxi Province was controlled by the active faults, physiognomy and the structure types of slopes; and that the types of super large landslides are different with distribution areas, so the types of super large landslides in Shaanxi were classified into six ones, including bedding landslide with loess-mudstone along the margin of Baoji loess tableland, inversion layer landslide with loess-red clay along the margin of Bailuyuan loess tableland in Baqiao, and interface landslide with loess-red clay.