{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,25]],"date-time":"2026-02-25T19:37:32Z","timestamp":1772048252647,"version":"3.50.1"},"reference-count":59,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2022,4,25]],"date-time":"2022-04-25T00:00:00Z","timestamp":1650844800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Research Grants Council of Hong Kong Special Administrative Region","award":["PolyU 152232\/17E and PolyU152164\/18E"],"award-info":[{"award-number":["PolyU 152232\/17E and PolyU152164\/18E"]}]},{"name":"Research Institute for Sustainable Urban Development, The Hong Kong Polytechnic University (RISUD)","award":["1-BBWB"],"award-info":[{"award-number":["1-BBWB"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>This study employed remote sensing (optical and synthetic aperture radar) and data analysis techniques to quantify vertical ground displacements and assess their contribution to coastline erosion. To provide evidence from Pakistan, we selected the coast of Karachi\u2014a mega-city located along the dynamic coastline of the Indus River Delta\u2014which has been experiencing severe coastal erosion during the last few decades. Observations from the C-band Envisat\/ASAR and Sentinel-1A sensors over the 2004\u20132010 and 2014\u20132016 periods, respectively, enabled us to study vertical ground displacements in the study area, providing a long-term assessment during 2004\u20132016. Results suggest that some areas along the Karachi coastline are subsiding at comparable rates to or even much higher than the relative sea-level rise (SLR, ~1.9 mm\/yr), which may amplify the rates of relative SLR in coming years, along with accelerating coastal erosion. Various parts of the study area along the coast are unstable and undergoing displacement. Landsat images from 1989 to 2018 (10-year temporal resolution) were further used to examine the state of coastline erosion using three statistical approaches (i.e., End Point Rate (EPR), Linear Regression Rate (LRR), and Least Median of Squares (LMS)). While the erosion underlaid the majority of the eastern sections of the study area, the ground displacements were spatially heterogeneous across the study area and along the coastline. Erosion rates of ~2.4 m\/yr spatially corresponded with ground displacement rates of up to ~\u22121.4 cm\/yr, but not all the coastline segments with high annual mean erosion rates were associated with local mean subsidence. The causes of ground displacements and coastline erosion were analyzed, and results were interpreted by integrating spatial ancillary information. Results indicate that rapid urbanization, construction on reclaimed land, coastline erosion favoring seawater intrusion, failed drainage\/sewerage networks, and soil liquefaction are contributing to the site-specific variations in the land displacement in Karachi.<\/jats:p>","DOI":"10.3390\/rs14092054","type":"journal-article","created":{"date-parts":[[2022,4,26]],"date-time":"2022-04-26T02:14:39Z","timestamp":1650939279000},"page":"2054","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":14,"title":["Vertical Ground Displacements and Its Impact on Erosion along the Karachi Coastline, Pakistan"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-3670-9949","authenticated-orcid":false,"given":"Shamsa","family":"Kanwal","sequence":"first","affiliation":[{"name":"Department of Land Surveying and Geo-Informatics, The Hong Kong Polytechnic University, Hong Kong SAR 999077, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5733-3629","authenticated-orcid":false,"given":"Xiaoli","family":"Ding","sequence":"additional","affiliation":[{"name":"Department of Land Surveying and Geo-Informatics, The Hong Kong Polytechnic University, Hong Kong SAR 999077, China"},{"name":"Research Institute for Land and Space, The Hong Kong Polytechnic University, Hong Kong SAR 999077, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2118-0963","authenticated-orcid":false,"given":"Songbo","family":"Wu","sequence":"additional","affiliation":[{"name":"Department of Land Surveying and Geo-Informatics, The Hong Kong Polytechnic University, Hong Kong SAR 999077, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1576-1342","authenticated-orcid":false,"given":"Muhammad","family":"Sajjad","sequence":"additional","affiliation":[{"name":"Centre for Geo-Computation Studies and Department of Geography, Hong Kong Baptist University, Hong Kong SAR 999077, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2022,4,25]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"71","DOI":"10.1016\/j.apgeog.2018.12.004","article-title":"Climate Change Impacts on Rice Productivity in the Mekong River Delta","volume":"102","author":"Kontgis","year":"2019","journal-title":"Appl. Geogr."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"24","DOI":"10.1016\/j.ancene.2014.02.003","article-title":"Anthropocene Metamorphosis of the Indus Delta and Lower Floodplain","volume":"3","author":"Syvitski","year":"2013","journal-title":"Anthropocene"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"681","DOI":"10.1038\/ngeo629","article-title":"Sinking Deltas Due to Human Activities","volume":"2","author":"Syvitski","year":"2009","journal-title":"Nat. Geosci."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"719","DOI":"10.1016\/j.jhydrol.2018.09.019","article-title":"Fluvial Sediment Transfer in the Changjiang (Yangtze) River-Estuary Depositional System","volume":"566","author":"Dai","year":"2018","journal-title":"J. Hydrol."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"597","DOI":"10.1016\/j.ecss.2016.06.017","article-title":"Coastal Inundation Risk Assessment Due to Subsidence and Sea Level Rise in a Mediterranean Alluvial Plain (Volturno Coastal Plain\u2014Southern Italy)","volume":"198","author":"Aucelli","year":"2017","journal-title":"Estuar. Coast. Shelf Sci."},{"key":"ref_6","unstructured":"Milliman, J.D., and Haq, B.U. (2013). Sea-Level Rise and Coastal Subsidence: Causes, Consequences, and Strategies, Springer Science & Business Media."},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Kanwal, S., Ding, X., Sajjad, M., and Abbas, S. (2020). Three Decades of Coastal Changes in Sindh, Pakistan (1989\u20132018): A Geospatial Assessment. Remote Sens., 12.","DOI":"10.3390\/rs12010008"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"6","DOI":"10.2112\/JCOASTRES-D-16-00208.1","article-title":"Beach Evolution Adjacent to a Seasonally Varying Tidal Inlet in Central Vietnam","volume":"34","author":"Do","year":"2018","journal-title":"J. Coast. Res."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"98","DOI":"10.1016\/j.jseaes.2011.08.014","article-title":"An Analysis of Coastal Erosion in the Tropical Rapid Accretion Delta of the Red River, Vietnam","volume":"43","author":"Duc","year":"2012","journal-title":"J. Southeast Asian Earth Sci."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"47","DOI":"10.1007\/s11852-016-0471-7","article-title":"Climate Change Impacts on a Large-Scale Erosion Coast of Hai Hau District, Vietnam and the Adaptation","volume":"21","author":"Duc","year":"2017","journal-title":"J. Coast. Conserv."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Khan, F.A., Khan, T.M.A., Ahmed, A.N., Afan, H.A., Sherif, M., Sefelnasr, A., and El-Shafie, A. (2020). Complex Extreme Sea Levels Prediction Analysis: Karachi Coast Case Study. Entropy, 22.","DOI":"10.3390\/e22050549"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"213","DOI":"10.1016\/B978-0-12-814003-1.00012-5","article-title":"The Indus Delta\u2014Catchment, River, Coast, and People","volume":"2019","author":"Kidwai","year":"2019","journal-title":"Coasts Estuaries"},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Kanwal, S., Ding, X., Sajjad, M., Nazeer, M., and Zia, I. (2021). Remote Sensing of Narrowing Barrier Islands along the Coast of Pakistan over Past 30 Years. J. Mar. Sci. Eng., 9.","DOI":"10.3390\/jmse9030295"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"601","DOI":"10.1785\/gssrl.78.6.601","article-title":"Seismic Hazard in Karachi, Pakistan: Uncertain Past, Uncertain Future","volume":"78","author":"Bilham","year":"2007","journal-title":"Seismol. Res. Lett."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"3305","DOI":"10.1002\/2015GL063686","article-title":"Coseismic and Postseismic Deformation Due to the 2007 M5.5 Ghazaband Fault Earthquake, Balochistan, Pakistan","volume":"42","author":"Fattahi","year":"2015","journal-title":"Geophys. Res. Lett."},{"key":"ref_16","unstructured":"Panhwar, M.H. (1999). Seepage of Water of the River Indus and Occurrence of Fresh Ground Water in Sindh. The Indus River: Biodiversity, Resources, Humankind, Oxford University Press."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Rahman, A.-U., Khan, A.N., and Shaw, R. (2015). Disaster Risk Reduction Approaches in Pakistan, Springer.","DOI":"10.1007\/978-4-431-55369-4"},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Amin, G., Shahzad, M.I., Jaweria, S., and Zia, I. (2021). Measuring Land Deformation in a Mega City Karachi-Pakistan with Sentinel SAR Interferometry. Geocarto Int., 1\u201315.","DOI":"10.1080\/10106049.2021.1903572"},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Kanwal, S., Ding, X., and Zhang, L. (2018, January 23\u201327). Measurement of Vertical Deformation in Karachi Using Multi-Temporal Insar. Proceedings of the IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2018), Valencia, Spain.","DOI":"10.1109\/IGARSS.2018.8518223"},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Shi, X., Liao, M., Li, M., Zhang, L., and Cunningham, C. (2016). Wide-Area Landslide Deformation Mapping with Multi-Path ALOS PALSAR Data Stacks: A Case Study of Three Gorges Area, China. Remote Sens., 8.","DOI":"10.3390\/rs8020136"},{"key":"ref_21","first-page":"1119","article-title":"InSAR Reveals Coastal Subsidence in the Pearl River Delta, China","volume":"191","author":"Wang","year":"2012","journal-title":"Geophys. J. Int."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"213","DOI":"10.1093\/gji\/ggu017","article-title":"Spatiotemporal Characteristics of the Huangtupo Landslide in the Three Gorges Region (China) Constrained by Radar Interferometry","volume":"197","author":"Li","year":"2014","journal-title":"Geophys. J. Int."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"2710","DOI":"10.1038\/srep02710","article-title":"Natural versus Anthropogenic Subsidence of Venice","volume":"3","author":"Tosi","year":"2013","journal-title":"Sci. Rep."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"537","DOI":"10.1007\/s10584-012-0468-7","article-title":"Evaluation of the Combined Risk of Sea Level Rise, Land Subsidence, and Storm Surges on the Coastal Areas of Shanghai, China","volume":"115","author":"Wang","year":"2012","journal-title":"Clim. Chang."},{"key":"ref_25","unstructured":"Hamid, G. (2011). Geotechnical Evaluation of Rocks and Soils of Karachi Area and Their Impact on Urbanization. [Ph.D. Thesis, University of Karachi]."},{"key":"ref_26","unstructured":"Gehlot, S., Ketelaar, V.B.H., Verbree, E., and Hanssen, R.F. (2005). Conceptual Framework for PS-InSAR Deformation Interpretation Assisted by Geo-Information Technology. High Resolut. Earth Imaging Geospat. Inf., 17\u201320."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"429","DOI":"10.1016\/j.rse.2011.10.020","article-title":"Mapping Ground Surface Deformation Using Temporarily Coherent Point SAR Interferometry: Application to Los Angeles Basin","volume":"117","author":"Zhang","year":"2012","journal-title":"Remote Sens. Environ."},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Soergel, U. (2010). Radar Remote Sensing of Urban Areas, Springer Science & Business Media.","DOI":"10.1007\/978-90-481-3751-0"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1911","DOI":"10.1109\/TGRS.2013.2256428","article-title":"Detecting Subsidence in Coastal Areas by Ultrashort-Baseline TCPInSAR on the Time Series of High-Resolution TerraSAR-X Images","volume":"52","author":"Liu","year":"2013","journal-title":"IEEE Trans. Geosci. Remote Sens. Lett."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"72","DOI":"10.3390\/rs70100072","article-title":"Investigation of Slow-Moving Landslides from ALOS\/PALSAR Images with TCPInSAR: A Case Study of Oso, USA","volume":"7","author":"Sun","year":"2014","journal-title":"Remote Sens."},{"key":"ref_31","first-page":"812","article-title":"Monitoring of Urban Subsidence with SAR Interferometric Point Target Analysis: A Case Study in Suzhou, China","volume":"13","author":"Zhang","year":"2011","journal-title":"Int. J. Appl. Earth Obs. Geoinf."},{"key":"ref_32","unstructured":"Zhang, L. (2012). Temporarily Coherent Point SAR Interferometry, The Hong Kong Polytechnic University."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"3529","DOI":"10.1109\/TGRS.2013.2273374","article-title":"A Novel Multitemporal InSAR Model for Joint Estimation of Deformation Rates and Orbital Errors","volume":"52","author":"Zhang","year":"2013","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_34","unstructured":"Ashrafianfar, N., Busch, W., Dehghani, M., and Haghighatmehr, P. (December, January 30). Differential SAR Interferometric Technique for Land Subsidence Monitoring Due to Groundwater Over-Exploitation in the Hashtgerd. Proceedings of the \u2018Fringe 2009 Workshop\u2019, Frascati, Italy."},{"key":"ref_35","unstructured":"Han, J.-Y. (2008). Interferometric Synthetic Aperture Radar Observation of Vertical Land Displacement in the Vicinity of the All-American Canal at the United States and Mexico Border, ProQuest."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"2021","DOI":"10.1109\/TGRS.2014.2352555","article-title":"NL-SAR: A Unified Nonlocal Framework for Resolution-Preserving (Pol)(In)SAR Denoising","volume":"53","author":"Deledalle","year":"2015","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_37","unstructured":"Zhang, L., Ding, X., and Lu, Z. (2011, January 19\u201323). Deformation Rate Estimation on Changing Landscapes Using Temporarily Coherent Point InSAR. Proceedings of the Fringe Conference, Frascati, Italy."},{"key":"ref_38","first-page":"102050","article-title":"Investigation of the Ground Displacement in Saint Petersburg, Russia, Using Multiple-Track Differential Synthetic Aperture Radar Interferometry","volume":"87","author":"Wang","year":"2020","journal-title":"Int. J. Appl. Earth Obs. Geoinf."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"8095","DOI":"10.1029\/2018JB016004","article-title":"Interseismic Ground Deformation and Fault Slip Rates in the Greater San Francisco Bay Area from Two Decades of Space Geodetic Data","volume":"123","author":"Xu","year":"2018","journal-title":"J. Geophys. Res. Solid Earth"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"3441","DOI":"10.5194\/hess-21-3441-2017","article-title":"Analysis of Data Characterizing Tide and Current Fluxes in Coastal Basins","volume":"21","author":"Armenio","year":"2017","journal-title":"Hydrol. Earth Syst. Sci."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"81","DOI":"10.1080\/1064119X.2018.1448912","article-title":"Shoreline Change Detection using DSAS Technique: Case of North Sinai Coast, Egypt","volume":"37","author":"Nassar","year":"2019","journal-title":"Mar. Georesources Geotechnol."},{"key":"ref_42","unstructured":"Niamatullah, M., and Imran, M. (2009, January 17\u201318). Structural Geometry and Tectonics of Southern Part of Karachi Arc\u2014A Case Study of Pirmangho & Lalji Area. Proceedings of the PAPG\/SPE Annual Technical Conference, Islamabad, Pakistan."},{"key":"ref_43","first-page":"9","article-title":"Riding the Mobile Karachi Arc, Pakistan: Understanding Tectonic Threats","volume":"46","author":"Sarwar","year":"2013","journal-title":"J. Himal. Earth Sci."},{"key":"ref_44","first-page":"35","article-title":"Earthquakes and the Neo-Tectonic Framework of the Kutch-Hyderabad-Karachi Triple Junction Area, Indo-Pakistan","volume":"14","author":"Sarwar","year":"2004","journal-title":"Pak. J. Hydrocarb. Res."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"6641","DOI":"10.1038\/s41598-018-24630-6","article-title":"The State of the World\u2019s Beaches","volume":"8","author":"Luijendijk","year":"2018","journal-title":"Sci. Rep."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"229","DOI":"10.1016\/j.apgeog.2017.12.015","article-title":"Building beyond Land: An Overview of Coastal Land Reclamation in 16 Global Megacities","volume":"90","author":"Sengupta","year":"2018","journal-title":"Appl. Geogr."},{"key":"ref_47","doi-asserted-by":"crossref","unstructured":"G\u00f3mez, J., Kwoll, E., Walker, I., and Shirzaei, M. (2021). Vertical Land Motion as a Driver of Coastline Changes on a Deltaic System in the Colombian Caribbean. Geosciences, 11.","DOI":"10.3390\/geosciences11070300"},{"key":"ref_48","doi-asserted-by":"crossref","unstructured":"Ellouz-Zimmermann, N., Lallemant, S.J., Castilla, R., Mouchot, N., Leturmy, P., Battani, A., Buret, C., Cherel, L., Desaubliaux, G., and Deville, E. (2007). Offshore Frontal Part of the Makran Accretionary Prism: The Chamak Survey (Pakistan). Thrust Belts and Foreland Basins, Springer.","DOI":"10.1007\/978-3-540-69426-7_18"},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"833","DOI":"10.1007\/s12665-016-5654-x","article-title":"Numerical Simulation of Groundwater Flow and Aquifer-System Compaction Using Simulation and InSAR Technique: Saveh Basin, Iran","volume":"75","author":"Jafari","year":"2016","journal-title":"Environ. Earth Sci."},{"key":"ref_50","unstructured":"Jafari, F., Javadi, S., and Karimi, N. (July, January 28). Forecasting of Subsidence Due to Groundwater over Exploitation using MODFLOW and Interferometry Technique in Radar Imagery. Proceedings of the 36th IAHR World Congress, The Hague, The Netherlands."},{"key":"ref_51","unstructured":"EMC (2017). Environmental Impact Assessment (EIA) \"Ferere Excellency\u2014A High Density Zone of Civil Lines, Karachi\" Residential Cum Commercial Project, EMC Paksitan Pvt. Ltd."},{"key":"ref_52","first-page":"9","article-title":"Assessment of Groundwater Quality in Coastal Region a Case Study of Qayyumabad, Karachi, Pakistan","volume":"7","author":"Khan","year":"2020","journal-title":"Asian Rev. Environ. Earth Sci."},{"key":"ref_53","unstructured":"JICA (2008). The Study on Water Supply and Sewerage System in Karachi in the Islamic Republic of Pakistan."},{"key":"ref_54","first-page":"89","article-title":"Liquefaction Potential along the Coastal Regions of Karachi","volume":"48","author":"Lodi","year":"2015","journal-title":"J. Himal. Earth Sci."},{"key":"ref_55","unstructured":"KMC, and Environmental Impact Assessment (EIA) (2014). Grade Separated Traffic Improvement Plan from Park Tower Intersection to A.T. Naqvi Roundabout, Environemtnal Management Consultatns."},{"key":"ref_56","unstructured":"EMC (2017). Environmental Impact Assessment Report \"Royal Marina Tower\" Residential Building Project, Environemtnal Management Consultatns."},{"key":"ref_57","doi-asserted-by":"crossref","unstructured":"Mahmud, S.A., and Sheikh, S.A. (2008). Earthquake Shocks and Liquefaction Threat to Dha and Clifton Areas, Karachi Pakistan. A Case Study. Geotechnical Engineering for Disaster Mitigation and Rehabilitation, Springer.","DOI":"10.1007\/978-3-540-79846-0_43"},{"key":"ref_58","unstructured":"Ilyas, F. (Dawn, 2016). Concern over 100 High-Rises under Construction in Karachi, Dawn."},{"key":"ref_59","doi-asserted-by":"crossref","first-page":"41","DOI":"10.5194\/isprsannals-I-7-41-2012","article-title":"Ultrashort-Baseline Persistent Scatterer Radar Interferometry for Subsidence Detection","volume":"I-7","author":"Liu","year":"2012","journal-title":"ISPRS Ann. Photogramm. Remote Sens. Spat. Inf. Sci."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/14\/9\/2054\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T23:00:37Z","timestamp":1760137237000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/14\/9\/2054"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,4,25]]},"references-count":59,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2022,5]]}},"alternative-id":["rs14092054"],"URL":"https:\/\/doi.org\/10.3390\/rs14092054","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,4,25]]}}}