Coastal regions are becoming increasingly vulnerable to flooding because of accelerating sea-level-rise(SLR),local ground subsidence,and the changes in topography and morphology.Moreover,coastal areas are usually high...Coastal regions are becoming increasingly vulnerable to flooding because of accelerating sea-level-rise(SLR),local ground subsidence,and the changes in topography and morphology.Moreover,coastal areas are usually highly urbanized and increased human activities have an effect on the stability and preservation of the environment.For instance,the growing demand for new lands to accommodate the population and the industrial facilities in China has required the design and the deployment of land-reclamation projects from the ocean,with a marked impact on fragile coastal eco-systems.Specifically,the Yangtze River and Pearl River Estuary,two major estuaries of the world,have long been subject to intensive human activities over the past decades.Long-term ground subsidence evolution,topographic changes,and morphological variation of the coastal regions have drawn great attention.This paper provides an overview of well-established Earth Observation(EO)remote sensing(RS)technologies that are employed to continuously monitor the changes of urbanized regions.The combined use of EO-based DInSAR analyses along with the knowledge of the geomorphology of the coastal regions allows a more precise picture of the SLR risk in the investigated coastal regions.In this paper,we will concentrate on remote sensing technologies that allow the gathering of heterogeneous information,such as those based on the use of synthetic aperture radar(SAR),satellite altimeters and tide gauge data.We will underline how human activities trigger changes in the living environment of coastal zones and the associated risks for the population.Observed coastline changes,coastal regions terrain subsidence,and offshore bathymetry have a pronounced effect on the increasing risk of flooding.Accordingly,we also present insights into some inundation model projections employed for evaluating the potential flooding risk in coastal regions.展开更多
The continuously available satellites of European Galileo currently reach more than 25.To explore the rationality and reliability of the L-band and satellite laser ranging(SLR)data processing strategies,we design the ...The continuously available satellites of European Galileo currently reach more than 25.To explore the rationality and reliability of the L-band and satellite laser ranging(SLR)data processing strategies,we design the Galileo L-band,the SLR-only,and the combined L-band/SLR dynamic precise orbit determination(POD)strategies by using the normal equations(NEQs)stacking,and investigate their continuity and stability by employing the Galileo L-band data and SLR observations for the time span of the whole year of 2023,based on the Bei Dou/GNSS analysis center platform of Shandong University by using the modified Bernese GNSS Software Version 5.4.The orbital consistency of the L-band 1-day solution is the best with the Three-dimensional Root-Mean-Square(3D-RMS)values of 3.6 cm compared with the Center for Orbit Determination in Europe Multi-GNSS Experiment(COM)orbits,the corresponding values is 1.4 cm,2.5 cm,and 2.3 cm in Radial,the Tangential,and the Normal(RTN)direction,respectively.While the SLR-only 9-day arc length is optimal with the RTN values of 5.3 cm,30 cm,and 38.2 cm,as well as the 3D-RMS values of 48.9 cm.Encouragingly,the difference of the orbital accuracy between the combined L-band/SLR multi-day solution and the COM orbits is reduced by 0.5 cm and 0.9 cm,0.6 cm and 1.2 cm in T-,and N-direction for the 3-and 5-day solution respectively.The corresponding values improve 0.7 cm and 0.9 cm,1.4 cm and 1.8 cm for the 3-and 5-day orbital overlaps difference between the combined L-band/SLR and the L-band solution.Take the E09 satellite as a case study,the SLR-only orbital accuracy is regularly optimized as the multi-day arc lengthens and with the sites increase.Furthermore,the SLR residuals of its three types of orbits further demonstrate the positive contribution of SLR to the combination of the GNSS and SLR techniques.展开更多
基金National Key Research and Development Program of China(No.2017YFE0100700)Natural Science Foundation of China(Nos.41801337,41976163)+4 种基金Research Grants of Science and Technology Commission of Shanghai Municipality(No.18ZR1410800)Fundamental Research Funds for the Central UniversitiesKey Laboratory of Land Subsidence Monitoring and Prevention,Ministry of Land and Resources(No.KLLSMP201503)Fund of the Director of the Key Laboratory of Geographic Information Science(Ministry of Education),East China Normal University(No.KLGIS2017C03)General Research Fund of Hong Kong Research Grants Council(RGC)(No.CUHK 14303818)。
文摘Coastal regions are becoming increasingly vulnerable to flooding because of accelerating sea-level-rise(SLR),local ground subsidence,and the changes in topography and morphology.Moreover,coastal areas are usually highly urbanized and increased human activities have an effect on the stability and preservation of the environment.For instance,the growing demand for new lands to accommodate the population and the industrial facilities in China has required the design and the deployment of land-reclamation projects from the ocean,with a marked impact on fragile coastal eco-systems.Specifically,the Yangtze River and Pearl River Estuary,two major estuaries of the world,have long been subject to intensive human activities over the past decades.Long-term ground subsidence evolution,topographic changes,and morphological variation of the coastal regions have drawn great attention.This paper provides an overview of well-established Earth Observation(EO)remote sensing(RS)technologies that are employed to continuously monitor the changes of urbanized regions.The combined use of EO-based DInSAR analyses along with the knowledge of the geomorphology of the coastal regions allows a more precise picture of the SLR risk in the investigated coastal regions.In this paper,we will concentrate on remote sensing technologies that allow the gathering of heterogeneous information,such as those based on the use of synthetic aperture radar(SAR),satellite altimeters and tide gauge data.We will underline how human activities trigger changes in the living environment of coastal zones and the associated risks for the population.Observed coastline changes,coastal regions terrain subsidence,and offshore bathymetry have a pronounced effect on the increasing risk of flooding.Accordingly,we also present insights into some inundation model projections employed for evaluating the potential flooding risk in coastal regions.
基金under the support of the National Natural Science Foundation of China(Grant No.42388102),ChinaYouth Fund of the Natural Science Foundation of Hebei Province(Grant No.D2023523003),China。
文摘The continuously available satellites of European Galileo currently reach more than 25.To explore the rationality and reliability of the L-band and satellite laser ranging(SLR)data processing strategies,we design the Galileo L-band,the SLR-only,and the combined L-band/SLR dynamic precise orbit determination(POD)strategies by using the normal equations(NEQs)stacking,and investigate their continuity and stability by employing the Galileo L-band data and SLR observations for the time span of the whole year of 2023,based on the Bei Dou/GNSS analysis center platform of Shandong University by using the modified Bernese GNSS Software Version 5.4.The orbital consistency of the L-band 1-day solution is the best with the Three-dimensional Root-Mean-Square(3D-RMS)values of 3.6 cm compared with the Center for Orbit Determination in Europe Multi-GNSS Experiment(COM)orbits,the corresponding values is 1.4 cm,2.5 cm,and 2.3 cm in Radial,the Tangential,and the Normal(RTN)direction,respectively.While the SLR-only 9-day arc length is optimal with the RTN values of 5.3 cm,30 cm,and 38.2 cm,as well as the 3D-RMS values of 48.9 cm.Encouragingly,the difference of the orbital accuracy between the combined L-band/SLR multi-day solution and the COM orbits is reduced by 0.5 cm and 0.9 cm,0.6 cm and 1.2 cm in T-,and N-direction for the 3-and 5-day solution respectively.The corresponding values improve 0.7 cm and 0.9 cm,1.4 cm and 1.8 cm for the 3-and 5-day orbital overlaps difference between the combined L-band/SLR and the L-band solution.Take the E09 satellite as a case study,the SLR-only orbital accuracy is regularly optimized as the multi-day arc lengthens and with the sites increase.Furthermore,the SLR residuals of its three types of orbits further demonstrate the positive contribution of SLR to the combination of the GNSS and SLR techniques.
