摘要
鲜水河断裂带是青藏高原东部川滇地块的一条重要边界断裂,全新世以来活动强烈,断裂带沿线岩土体结构破碎强烈,在断裂活动诱发地震、断裂蠕滑和强降雨等因素作用下,断裂带沿线滑坡、泥石流等地质灾害发育密度大,危害严重。在前人研究的基础上,采用短基线集(SBAS-InSAR)的方法,基于日本对地观测卫星(ALOS-1)所获得的2007—2011年期间15景PALSAR数据,对鲜水河断裂带道孚至炉霍段的活动速率进行分析计算,获取了该段断裂带内蠕滑型滑坡5年间的时间序列形变特征。研究结果表明:鲜水河断裂带道孚至炉霍段近年来以蠕滑滑动为主,蠕滑速率为(9.4±0.78)mm/a,断裂的蠕滑作用对区域构造应力场和断裂带内滑坡具有重要的控制作用,表现为距离鲜水河断裂带越近,影像间相干性越强,稳定的相干点越多,干涉效果越好,滑坡滑动累计位移越大。沿鲜水河断裂道孚至炉霍段,共识别出98个蠕滑型滑坡,沿鲜水河断裂带两侧呈线性展布,并分析了典型蠕滑型滑坡的地表形变特征。基于SBAS-InSAR的雷达数据处理方法,可以有效地分析地表的缓慢变形以及区域性蠕滑型滑坡的发育发展变化规律,研究结果对于鲜水河断裂带沿线防灾减灾及类似构造活动地区的地质灾害研究具有一定的指导作用。
Xianshuihe Fault is one of the most important boundary fault on the eastern Tibetan Plateau of Sichuan-Yunnan block,and it is strongly active since the Holocene.The rock-mass and soil-body structures are porous along the Xianshuihe Fault zone.Under the action of earthquake caused by the active fault and its slowly moving and heavy rainfalls,landslides and debris flows occur frequently and have caused serious harm in this area.On the basis of the previous studies,SBAS-InSAR (small baseline subset interferometric synthetic aperture radar) method is employed to analyze and calculate the activity rate of Daofu to Luhuo section in Xianshuihe Fault zone combined with fifteen PALSAR scene data acquired by ALOS-1 during 2007-2011.And the deformation characteristics of time series are also acquired about the creeping landslide occurringalong Xianshuihe Fault in these five years.The results show that in recent years the creeping in Daofu to Luhuo section is the mainly active type for the fault,and the creeping rate is about (9.4 ± 0.78) mm/a,and the creeping effect of the fault has an important influence on the occurrence of landslides in this area.While the distance from Xianshuihe Fault is closer,the coherence among images is stronger,and coherent points are more stable and the interference effect is better,thus the cumulative displacement of landslides is greater.Ninety-eight creeping landslides along Daofu to Luhuo section of Xianshuihe Fault are identified,linearly distributing along both sides of the fault; the surface deformation characteristics of the typical creep landslide is also analyzed.Based on SBAS-InSAR Radar Data Processing method,we can effectively analyze the slow deformation of the surface,and the changing and developing laws of these regional creeping landslides.This study plays a certain guiding role on the prevention and mitigation of geohazards along Xianshuihe Fault and in the other similar areas.
出处
《现代地质》
CAS
CSCD
北大核心
2017年第5期965-977,共13页
Geoscience
基金
中国地质调查局项目(12120113038000)
国家自然科学基金项目(41402321)
中铁二院科研计划项目(二院科字201303)
关键词
短基线集
鲜水河断裂
蠕滑
滑坡
Luhuo section
fault
creeping rate
occurrence
landslides
area
Xianshuihe
coherence among images
Ninety-eight