Analyzing land subsidence using Multi-temporal Interferometric Synthetic Aperture Radar (MT-InSAR) technology holds significant importance for the secure development of urban areas. Shenzhen, being a crucial component of the Pearl River Delta, faces the threat of land subsidence, similar to most deltaic cities. Numerous studies have already indicated the presence of severe land subsidence in certain localities of Shenzhen. However, due to limitations in data scope and research methodologies, the comprehensive spatial-temporal distribution of land subsidence across the entire city of Shenzhen remains unclear. This study initially employed MT-InSAR technology to process a total of 534 Sentinel-1A SAR images from three different frames (P11F71, P113F71, P11F65), covering the entire city of Shenzhen. This processing resulted in the generation of subsidence rate maps and subsidence time series. Subsequently, the temporal evolution patterns of the subsidence were analyzed while significant subsidence regions were identified. By integrating information from optical images reflecting human activities on the Earth’s surface, the study deduced the subsidence mechanisms in various significant subsidence areas. Research findings indicate that land subsidence in Shenzhen is primarily caused by construction activities, with a concentration in the western coastal areas of Shenzhen, reaching a maximum rate of 80 mm/yr, located at the estuary of Dongbao River (113.770385, 22.745305). The cumulative subsidence from March 2017 to June 2023 amounts to 500 mm. The expansion of the Qinglinjing Reservoir has led to an increased demand for water, resulting in a significant rise in formation pressure and subsequent land subsidence. InSAR land subsidence monitoring and analysis in urban areas can address the spatial and temporal resolution limitations of traditional subsidence monitoring methods, providing effective recommendations for widespread subsidence prevention and control.

中文翻译：

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深圳市地面沉降时空特征及驱动因素分析

利用多时相干涉合成孔径雷达（MT-InSAR）技术分析地面沉降对于城市地区的安全发展具有重要意义。深圳作为珠江三角洲的重要组成部分，与大多数三角洲城市类似，也面临着地面沉降的威胁。大量研究已经表明深圳某些地区存在严重的地面沉降。但由于数据范围和研究方法的限制，深圳市全市地面沉降的综合时空分布仍不清楚。本研究首先采用MT-InSAR技术处理了来自三个不同帧（P11F71、P113F71、P11F65）的总共534张Sentinel-1A SAR图像，覆盖了整个深圳市。该处理生成了沉降速率图和沉降时间序列。随后，分析了沉降的时间演化模式，同时确定了重要的沉降区域。该研究通过整合反映地球表面人类活动的光学图像信息，推导了各个重要沉降区的沉降机制。研究结果表明，深圳地面沉降主要是由施工活动引起的，集中在深圳西部沿海地区，最大沉降速度达80毫米/年，位于东宝河口(113.770385, 22.745305)。 2017年3月至2023年6月累计沉降量达500毫米。青林井水库扩建导致用水量增加，导致地层压力大幅上升，导致地面沉降。 InSAR城市地区地面沉降监测与分析可以解决传统沉降监测方法的时空分辨率限制，为大面积沉降防治提供有效建议。