Monitoring and analysis of surface deformation of Tidal Flat in Maowei Sea on the basis of Sentinel active and passive remote sensing
Tidal flats possess significant economic value,environmental importance,and ecological functions,yet their fragile environments are highly susceptible to degradation due to both natural factors and human activities.The changes in surface elevation of tidal flats have a direct impact on the stability of the ecological environment,making the monitoring of tidal flat surface deformation essential for understanding how these ecosystems respond to environmental changes and for predicting the evolution of tidal flat patterns,which in turn provides crucial data for the protection and restoration of the ecological environment.However,the measurement methods currently employed for tidal flat surface deformation are predominantly limited to traditional positioning techniques,which are constrained by the complex environmental factors inherent to tidal flats,thus impeding large-scale estimations.In this context,the emerging InSAR technology offers a promising solution to overcome these limitations.Therefore,this study aims to monitor the surface deformation of the Maowei Sea tidal flats by employing time-series InSAR technology,applying this advanced technique to coastal tidal flat areas.Specifically,we utilized the SBAS-InSAR technique in conjunction with PS feature points,drawing on 176 scenes of Sentinel-1A SAR image data from the study area to extract surface deformation information spanning from 2015 to 2022.By analyzing data on vegetation distribution,precipitation,sea level rise,and geological background within the study area,we conducted a comprehensive examination of the overall characteristics,spatiotemporal evolution trends,and influencing factors of surface deformation in the region.The results show that:(1)The surface deformation of the tidal flat area demonstrates significant spatial heterogeneity,with distinct subsidence and uplift trends across different regions.Over the study period,the surface deformation rate within the study area ranged from-43.07 to 36.22 mm per annum,with deformation being unevenly distributed and generally exhibiting a slight uplift trend,while specific areas such as Jianshan and Mangrove Bay displayed a subsidence trend,in contrast to the uplift trend observed in the Kangxiling region.(2)Through time-series analysis of multiple feature points,it was revealed that the deformation in regions with severe subsidence is characterized by significant temporal heterogeneity,with some areas exhibiting periodic alternating uplift and subsidence,and an overall uneven subsidence trend over time,with a maximum subsidence of-184.9 mm observed over four years.(3)In terms of the factors influencing deformation,the study identifies biological activities,human activities,hydrological processes,sea level rise,and precipitation-induced geomorphological changes as the primary drivers of surface deformation in tidal flats,with these factors collectively contributing to the diversity and complexity of deformation patterns in the region.In conclusion,by employing the SBAS-InSAR technique in combination with PS feature points and Sentinel-1A data,this study successfully achieved refined monitoring of surface deformation within the study area,revealing long-term spatiotemporal changes in displacement rates and cumulative deformation over a seven-year period,thereby providing robust inversion results that offer valuable scientific insights for the protection and restoration of the Maowei Sea ecological environment.
remote sensingland subsidenceInSARSentineltime series analysisTidal flatMaowei Sea Mangrove
万方数据
维普
