PSInSAR technique to monitor coastal lowland subsidence along the Eastern Coast of China - a case study in Zhejiang coast

摘要

Using RADARSAT-2 satellite images from January 2012 to October 2015, this paper employ the PSInSAR(Permanent Scatterer InSAR) technique to acquire coastal lowland subsidence in Zhejiang province. In the Hangzhou Bay Region, the widely distributed silt deposition leads to the entire ground sinking slowly, with 10~20mm/a in rate. Conversely, the ground subsidence distribution of the Eastern Coastal Region appear be funnel-shaped. Its involving area is small, while the settlement gradient of settlement center is comparatively large, whose maximum is more than 20mm/a. It is clear that the over-exploitation groundwater may be the main force in pace with the growth of factories and plenty of population. However, the distribution characteristic of ground subsidence in distinct regions could be determined by different geological structure. Therefore the environmental capacity of Zhejiang's coast is relatively vulnerable, and the ground subsidence is extremely prominent. Nowadays, the main undertaking is to vigorously restrict groundwater extraction and make seawater dilute in order to keep a comfortable environment to live in.