Characterisation and mapping of land subsidence based on geodetic observations in Lagos,Nigeria

作     者：Ikuemonisan Femi Emmanuel Ozebo Vitalis Chidi Ikuemonisan Femi Emmanuel;Ozebo Vitalis Chidi

作者机构：Department of PhysicsFaculty of ScienceUniversity of LagosAkokaLagosNigeria 

出 版 物：《Geodesy and Geodynamics》 (大地测量与地球动力学（英文版）)

年 卷 期：2020年第11卷第2期

页      面：151-162页

学科分类：081803[工学-地质工程] 08[工学] 0818[工学-地质资源与地质工程] 

基　　金：GLDAS Geohazards Thematic Exploitation Platform Jet Propulsion Laboratory, JPL European Space Agency, ESA 

主　　题：InSAR P-SBAS Deformation time series Land subsidence Lagos 

摘      要：The pervasive seasonal flooding,aquifer contamination,and saline water intrusion in parts of Lagos are some of the long-term effects of land subsidence caused by the excessive groundwater exploitation and land reclamation that has been taking place in the *** to monitor the extent and pattern of land deformation will help in many ways to mitigate the effects of flooding and other geohazards associated with land *** this study,we characterised and mapped the land subsidence in the Lagos city based on the analyses of geodetic data,which included Global Positioning Satellite(GPS),Envisat,Sentinel-1,and GRACE *** applied the SBAS technique to the Envisat and Sentinel-1 datasets acquired from 2004-2011 and 2015-2019,respectively,and to perform multi-temporal analyses and produce corresponding subsidence maps over the Lagos *** GRACE data were used to infer the extent and trend of groundwater changes at the GPS *** results indicate that the subsidence is a widespread phenomenon in Lagos city,with subsidence rates varying between-2 mm/year and-87 mm/*** highest subsidence rate was observed around the coastal zones and areas where heavy structures are built on *** the highest rate at present,subsidence has gradually increased in the last 15 *** the development of indiscriminate groundwater exploitation,urbanization,and rapid population growth,the subsidence rate in Lagos city is likely to rise significantly in the coming years,which,in turn,may further escalate the flood rate and other associated geohazards.