基于SBAS技术的天津市地面形变特征分析

地面沉降是一种普遍存在的地质灾害，天津是我国地面沉降较为严重的城市之一，对地面形变特征的研究，有助于了解地面沉降分布，合理进行城市规划。基于覆盖天津地区的Sentinel-1升轨和降轨数据，使用改进的小基线时序干涉测量方法获取卫星视线向（line of sight，LOS）向形变速率场，针对沿海地区大气影响严重等问题，引用InSAR通用大气校正在线服务（Generic Atmospheric Correction Online Service for InSAR , GACOS）模型去除大气误差影响。从获取的天津地区形变速度场可以看出，天津市区内形变量相对较小，市区周边的静海区、西青区存在一定的形变漏斗，最大LOS向形变量约-40mm/a；武清区和北辰区形变量最大，有一个范围和形变量级都较大的形变漏斗，形变漏斗中心为武清区王庆坨镇，其最大LOS向形变量在升轨和降轨结果中分别为80mm/a和99.2mm/a，结合该区域土地利用情况，发现主要是由于产业园密集建设，导致工业和生活用水过度导致地下水超采。从形变结果可以看出，后续需要对存在形变漏斗的区域进行科学用水管理和合理城市规划，从而有效改善区域形变的影响。

Analysis of ground deformation characteristics in Tianjin Based on SBAS Technology

Land subsidence is a common geological disaster. Tianjin is one of the cities with serious land subsidence in China. The research on the characteristics of land deformation is helpful to understand the distribution of land subsidence and carry out urban planning reasonably. Based on the sentinel-1 orbit raising and descending data covering the Tianjin area, the satellite line of sight (LOS) deformation rate field was obtained by using the improved small baseline timing interferometry method. Aiming at the serious atmospheric impact in coastal areas, the GACOS (Generic Atmospheric Correction Online Service for InSAR) atmospheric correction model was used to remove the influence of atmospheric error. From the obtained deformation velocity field in Tianjin, it can be seen that the shape variable in Tianjin urban area was relatively small, there was a certain deformation funnel in Jinghai district and Xiqing District around the urban area, and the maximum LOS direction shape variable was about - 40mm/a. Wuqing District and Beichen District had the largest shape variables, and there was a deformation funnel with a large range and shape variable level. The center of the deformation funnel is wangqingtuo Town, Wuqing district. The maximum LOS direction shape variables in the track lifting and track lowering results are 80mm/a and 99.2mm/a respectively. Combined with the land use situation in this area, it is found that it is mainly due to the intensive construction of industrial parks, leading to excessive industrial and domestic water consumption, resulting in overexploitation of groundwater. It can be seen from the deformation results that it is necessary to carry out scientific water management and reasonable urban planning for the areas with a deformation funnel, to effectively improve the impact of regional deformation.