利用Sentinel-1A数据监测大西安2015—2017年地面沉降

Monitoring Xi'an land subsidence during 2015—2017 using Sentinel-1A images

大西安地区包括西安市辖区及周边市县,是我国地面沉降和地裂缝等地质灾害集中发育的地区之一.采用短基线集InSAR技术对覆盖该地区2015年6月至2017年3月期间的29景升轨Sentinel-1A数据进行处理,获取了大西安地区该期间的地面沉降分布特征,分析了地面沉降与地裂缝之间的相互关系.研究结果表明:(1)2015—2017年间最大沉降速率达到30 mm/a以上的区域主要包括西安市辖区、户县、临潼区、蓝田县;(2)西安市的沉降灾害最为严重,包含5个典型的沉降区域,最大沉降中心位于西安市西郊的鱼化寨,沉降速率达到136 mm/a,其次长安县航天产业园是新发现的沉降区域,其形变速率为-36 mm/a;(3)西安市的地面沉降受地下水开采影响,而其空间分布受构造断裂及地裂缝控制.

The Xi’an, including Xi’an city and its surrounding cities and countries, is one of the regions where severe geological hazards have been occurred for a long time and with high frequency, including land subsidence and ground fissures. Twenty-nine scenes ascending Sentinel-1 A images covering this area from June 2015 to March 2017 were processed based on Small Baseline Subset(SBAS) InSAR technique to reveal the spatial distribution characteristics of land subsidence, and to analyze the interaction between land subsidence and ground fissures. Results showed that:(1) The maximum annual subsidence rate of Xi’an, Hu country, Lintong district and Lantian county reached more than 30 mm/a from 2015 to 2017;(2) Xi’an was the most serious subsidence region and five main land subsidence zones had been detected. The maximum subsidence center was Yuhuazhai district, in the west of Xi’an city, of which the annual subsidence rate reached 136 mm/a. Then a new subsidence zone had been found in aerospace industrial park over Chang’an county, of which the annual subsidence rate reached-36 mm/a.(3) Land subsidence in Xi’an city was influenced by groundwater exploitation, while its spatial distribution was controlled by ground ?ssures and faults.