川西地区地质灾害发育特征与时空分布规律

川西地区受青藏高原隆升和发育于青藏高原的大江大河深切割等作用，共发育地质灾害16411处，以滑坡和泥石流为主，是我国地质灾害高风险地区。本文采用资料收集、数理统计、Arcgis软件分析等方法分析发现，川西地质灾害具有成因机制复杂，突发性、群发性与链生性、危害大等特点。形成机理差异大，滑坡变形模式以滑移-拉裂、蠕滑-剪断、倾倒折断等模式为主；泥石流形成机理主要为土力-水力驱动型和堵溃型；崩塌失稳主要表现为滑移式、倾倒式和坠落式。发育分布规律在低山和中山区呈带状，和沿活动断裂带和深切河谷呈线状集中分布；受地震和强降雨影响，地质灾害年际变化大，2008、2009、2013年、2017年地质灾害频发、高发和群发期。

Characteristics and temporal-spatial distribution of geohazards in western Sichuan

Affected by the uplifting of the Qinghai-Tibet Plateau and the deep cutting of rivers in the Qinghai-Tibet Plateau, a total of 16,411 geohazards, mainly landslides and debris flows, have developed in the western Sichuan, which is an area with high risk of geohazards in China. By means of data collection, mathematical statistics and ArcGIS software analysis, we find that the geohazards are characterized by complex formation mechanism, sudden-group-chain occurrence, and great harm in Western Sichuan. The formation modes of geological disasters are different. The main deformation modes of landslides are slip-crack-shear, retaining wall-break, along the bedding creep-shear, toppling fracture of antidumping rock, etc. The formation mechanism of debris flow are mainly soil - hydraulic drive type and blocking collapse type. Collapse instability mainly includes sliding, toppling and falling. The spatial distribution are mainly controlled by landform and active faults, which are of the distribution of a zone in the low and middle mountains, and a certain band along the active fault zone and deep river valley. Affected by earthquakes and heavy rainfall, geological disasters vary greatly from year to year. Geological disasters occurred frequently and frequently in 2008, 2009, 2013 and 2017.