Abstract:This study conducts image processing of 33 ENVISAT ASAR data covering the northern area of Langfang city and extracts the annual average velocity and quarterly series information of land subsidence in the time span of 2007-2010. In addition, coupled analysis of subsidence monitoring data and influencing factors information is carried out to analyze causes. The results show: that the higher scale settlement areas are mainly distributed in Songzhuang-Yanjiao, Wubaihu-Dakoutun and other scattered areas with seasonal fluctuation due to rainfall recharge; there appear differential subsidence characteristics exhibiting high subsidence gradients in the mountain frontier and Yanggezhuang-Mafang areas, while monotonous appearances between rather high land subsidence gradient distributions and the -16 mm/a and 0 mm/a contour lines; there are rather high or gradual subsidence gradients on both sides of the faults in the northern and eastern parts of study area, due to the fault activities and significant difference in the thickness and structure of Quaternary aquifers system; an high agreement with the distributions of water head sites and drawdown area, revealing that the overexploitation of deep confined water and urbanization construction are the primary cause of severe subsidence.
LI Haijun,ZHANG Yaowen,GU Hongbiao et al. Land Subsidence Detection Based on PS-InSAR Technology in Northern Area of Langfang City[J]. jgg, 2018, 38(11): 1122-1127.