Ground Subsidence Rate Inversion of Large Temporal and Spatial Scales Based on Extended PSInSAR Method

Estimation of processes for slow change in small scale surfaces is one of the main advantages of PSInSAR technology. We present a mathematical framework for the datum connection for time-space referencing, applying it to 500 scenes composed of Envisat ASAR images covering about 200 000 km(2) of the North China Plain, obtained the rate of ground subsidence in the study area during the period of 2006-2010. The experimental results show that: (1) the multiple subsidence centers in North China Plain were still in an evolving state, connecting Beijing, Langfang, Tianjin, Renqiu, Cangzhou, Botou, Hengshui, Dezhou, Nangong and Handan into a continuous area. (2) The most prominent ground subsidence was in Tianjin's Jinghai and Binhai areas having average subsidence rates of 62mm/a and 67mm/a along the line of sight, respectively. The subsidence of the old centers, to the east of Beijing, Cangzhou, Botou - Hengshui - Dezhou, Handan, had rates of 36mm/a, 34mm/a, 37mm/a, 29mm/a,respectively. (3) The experimental results were validated with leveling data in Tianjin area. The difference between the two methods is less than 10 mm, which shows that the results obtained by the PSInSAR technique are consistent with those obtained by leveling. (4) The results here presented can be used as development prevention reference measures of regional ground subsidence.