SURFACE SUBSIDENCE MONITORING IN GANZHOU AREA BASED ON SBAS-INSAR

Abstract. In this paper, we first obtained the temporal-spatial changes of surface subsidence in Ganzhou area based on SBAS-InSAR technology using 24 scenes Sentine-1A images covering the Ganzhou area from 2018 to 2020. Then we studied the surface subsidence characteristics in the study area. Finally, the relationship between surface subsidence and factors such as precipitation, human engineering activities, groundwater extraction, and sediment accumulation were analyzed in Ganzhou area. The results showed that : 80% of the sedimentation rate was −5.4–3.0 mm/a in the study area; serious subsidence areas were mainly located in Ganxian District, which annual average subsidence rate reached −26.4mm/a, and the time series of surface subsidence was accompanied by certain seasonal changes; the seasonal changes in surface subsidence were related to rainfall and groundwater extraction, in addition, the surface subsidence was obviously affected by human engineering activities and river sediment accumulation.