西秦岭断裂构造系统基本特征及其对地质灾害的控制 作用

通过对青藏高原东北缘西秦岭地区断裂构造系统的特征及与滑坡、泥石流等地质灾害关系的分析研究,探讨了断裂构造系统对滑坡、泥石流等地质灾害的形成和分布的控制作用。认为虽然滑坡、泥石流等地质灾害是内外动力地质作用复杂的联合作用的结果,但断裂构造系统及其活动性对滑坡、泥石流等地质灾害形成具有关键性的作用,这种作用方式有直接和间接之分。西秦岭地区典型的滑坡、泥石流等的形成大多与断裂构造及其活动密切相关,主要表现在:(1)断裂构造发育的区域一般是滑坡、泥石流高发区;(2)断裂带活动为滑坡和泥石流的发生提供了物源和结构条件;(3)断裂的地震活动是诱发滑坡的关键因素;(4)断裂带的长期活动形成的构造破碎带和地形高差易于为流水的侵蚀而形成泥石流沟和陡坡地形。因此在对滑坡、泥石流等地质灾害研究中,不应孤立的认识单个滑坡、泥石流的形成与发展,而应把其放在区域地质环境演化中去认识,尤其是把区域断层格架、断层带结构和断层活动性研究作为地质灾害形成与发展的关键影响因素深入研究,从而为科学认识崩塌、滑坡、泥石流等地质灾害的形成过程、制定科学的灾害的防御和治理方案提供科学依据。

THE CHARACTERISTICS OF THE FAULT SYSTEM AND ITS CONTROLLING FOR THE GEOLOGICAL HAZARDS IN THE WESTERN QINLING

Based upon the investigation of the characteristics of fault systems and analysis for the relationship between the fault systems and landslide, debris flow et al geological hazards in the westen Qingling, the controlling function of fault system for geological hazard development is discussed. It is proposed that fault systems and its activities are essential factors for the development of geological hazards although geological hazards are actually the results of complex and composite actions of interior and exterior dynamic geological processes. The controlling functions of fault system for geological hazard development could be direct or indirect, mainly as follow, (1)the geological hazards generally develop along the faults, which often determines the intensity and spatial distribution of geological hazards; (2) the fractural zone and influence zone of faults often provide mass debris substance and structural slide faces for landslide and mud-debris flow; (3) the fault activities, especially earthquake activity of faults are the important induced factor for geological hazards; (4) fractured rocks and geomorphic height contrasts for the prolonged activity of faults provide the favorite conditions for water corrosion, which would develop the slope geomorphic condition for geological hazards. Therefore in studying landslide and mud-debris flow, we should put them under the regional geological background, especially regional fault framework, fault zone structural features and fault activities, to understand its development..