InSAR技术支持下的长沙市2015—2021年地面沉降监测分析

Monitoring and analysis of the subsidence in Changsha from 2015 to 2021 based on InSAR technique

长沙市是长江中游地区重要的中心城市,地质条件脆弱、土质疏松,土体在施工和降雨作用下极易固结压实,造成地面形变,威胁建筑物和基础设施的稳定。地面沉降是长沙市地质灾害的主要原因之一。为了监测长沙市近几年的地面沉降情况,本文使用MCTSB-InSAR方法,利用151景Sentinel-1SAR影像数据,获取了长沙市主城区2015—2021年的地面沉降结果。经分析发现,最大累计沉降量约为250 mm,最大沉降速率约为80 mm/a,绝大部分区域平均沉降速率在30 mm/a以下;长沙市整体稳定,局部有不均匀沉降发生,沉降区域主要分布在主城区外围,主要由工程施工引起。

Changsha city is an important central city in the middle reaches of Yangtze River.The geological condition is fragile and the soil is loose.Under the action of construction and rainfall,the soil is easy to consolidate and compact,resulting in ground deformation and threatening the stability of buildings and infrastructure.Land subsidence is one of the main causes of geological disasters in Changsha city.In order to monitor the land subsidence of Changsha city in recent years,we use the technology of MCTSB-InSAR and 151 Sentinel-1 data to obtain the land subsidence results of the main urban area of Changsha City from 2015 to 2021.The results show that the maximum accumulated settlement is about 250 mm,the maximum settlement rate is about 80 mm/a,and the average settlement rate in most areas is below 30 mm/a.The overall stability of Changsha city,local uneven settlement occurred,settlement area mainly distributed in the periphery of the main city,mainly caused by engineering construction.