基于SBAS-InSAR技术的安徽省砀山县地面沉降监测

皖北地区地貌形态以平原为主,地面沉降是其面临的主要地质灾害。基于小基线集(small baseline subsets-interferometric synthetic aperture radar, SBAS-InSAR)方法,利用2017年5月至2021年12月期间采集的47景Sentinel-1A SLC (single look complex,SLC) 升轨数据对砀山县进行地表形变监测,获得了砀山地区该时段年均形变速率和地表累计形变图,揭示了监测期间该区的形变时空分布和变化特征。结果表明: 以砀城镇为中心,包含高铁新区及经济开发区一带地表沉降明显,黄河故道以北,沿玄庙镇东西方向发生微量沉降,沉降的分布与地下水过量开采以及岩土性质密切相关。定期监测地面沉降的分布和量级,能够缓解日益增长的城市化人口暴露于这类灾害下的风险。

Analysis of monitoring ground subsidence in Dangshan County of Anhui Province based on SBAS-InSAR technology

The landforms in North Anhui are dominated by plains, and the land subsidence is the main geological disaster. Based on the Small Baseline Subsets (Small Baseline Subsets-Interferometric Synthetic Aperture Radar, SBAS-InSAR) method, the surface deformation in Dangshan County was monitored through the 47 scenes Sentinel-1A ascending SLC (Single Look Complex) imageries acquired from May 2017 to December 2021. The distribution maps of ground subsidence and the cumulative surface displacement map of the Dangshan area during monitoring period were obtained, and the temporal-spatial variation characteristics of subsidence in this area were analyzed. The results revealed that the ground subsidence are significant in Gaoxin District and Economic Development District, revolving around the Dangcheng Town. Moderate subsidence occurred along the east-west direction of Xuanmiao Town in north of the old Yellow River, and distribution of subsidence is closely related to the overexploitation of groundwater and the geotechnical properties. Regular monitoring of the distribution and magnitude of land subsidence can mitigate the exposure of a growing urbanized population to such hazards.