摘要
岷江上游峡谷区滑坡等地质灾害频发,认识灾害的分布特征及诱因对于减小灾害损失具有重要意义。基于2015~2019年的60景哨兵一号(Sentinel-1A)卫星雷达影像,采用小基线集合成孔径雷达干涉测量(SBAS-InSAR)方法获取了地表雷达视线向形变的时间序列及多年平均速率,分析了地表沉降的分布规律及其同植被覆盖、降水、人类活动等因子的内在联系。结果表明:研究区地表沉降具有明显的坡向分异规律,即快速沉降区多分布于阳坡,年平均沉降速率(-33.02 mm/a)明显快于阴坡(-9.33 mm/a)。针对该地表沉降的坡向分异规律,研究进一步揭示了其环境控制机制:(1)阳坡水分条件胁迫较强而植被覆盖差,不利于地表稳定;(2)地形雨来向多为偏南方向,阳坡受侵蚀较为强烈;(3)阳坡光热条件好,受垦殖等人类活动影响大。由此建议:在岷江上游峡谷区的偏南向边坡,应特别注意防范滑坡等灾害,加强地表形变监测和滑坡灾害预警。
The Upper Minjiang Basin,in the eastern Tibetan Plateau,is characterized by complex rugged ter⁃rains,so it was vulnerably subjected to surface subsidence related hazards.Therefore,it was quite beneficial and necessary to explore the controls underlying subsidence for disaster mitigation and avoidance.In the study,totally 60 Sentinel-1A images were chosen to detect possible surface subsidence from 2015 to 2019 with the in⁃terferometric synthetic aperture radar(InSAR)method in the study area,and then the factors underlying the subsidence were discussed.The results showed that south(sunny)slopes experienced the higher subsidence rate(averagely-33.02 mm/a)than the north(-9.33 mm/a)though with similar elevation and slope degree.The spatial patterns of subsidence could be attributed the terrain aspect related factors.The sparse vegetation cover on sunny slopes due to severer water deficit provided the weak protection to surface stability,and the physical erosion induced by the northward orographic rain was also not beneficial to the stability of south slopes.In addition,sunny slopes abundant in solar energy were subjected to more human activities such as farming and building,which also could weaken surface stability.Our study emphasized the distinct vulnerability in surface stability of south slopes in this region,which should be carefully taken into account in land developing as so to avoid causing landslides.
作者
肖洪敏
张文江
田云锋
蒋蕙如
朱强
Xiao Hongmin;Zhang Wenjiang;Tian Yunfeng;Jiang Huiru;Zhu Qiang(College of Water Resources and Hydropower,Sichuan University,Chengdu 610065,China;National Institute of Natural Hazards Prevention,Ministry of Emergency Management,Beijing 100085,China;Information Center,China Three Gorges Corporation,Beijing 100038,China)
出处
《遥感技术与应用》
CSCD
北大核心
2023年第4期967-977,共11页
Remote Sensing Technology and Application
基金
国家自然科学基金面上项目(41771112)资助。
