{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,11]],"date-time":"2026-05-11T11:06:51Z","timestamp":1778497611499,"version":"3.51.4"},"reference-count":55,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2021,12,31]],"date-time":"2021-12-31T00:00:00Z","timestamp":1640908800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100003093","name":"Ministry of Higher Education","doi-asserted-by":"publisher","award":["R.J130000.7852.5F290"],"award-info":[{"award-number":["R.J130000.7852.5F290"]}],"id":[{"id":"10.13039\/501100003093","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100005417","name":"University of Technology Malaysia","doi-asserted-by":"publisher","award":["Q.J130000.2452.09G29"],"award-info":[{"award-number":["Q.J130000.2452.09G29"]}],"id":[{"id":"10.13039\/501100005417","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100005417","name":"University of Technology Malaysia","doi-asserted-by":"publisher","award":["Q.J130000.2652.17J58"],"award-info":[{"award-number":["Q.J130000.2652.17J58"]}],"id":[{"id":"10.13039\/501100005417","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJGI"],"abstract":"<jats:p>Estimating surface elevation changes in mangrove forests requires a technique to filter the mangrove canopy and quantify the changes underneath. Hence, this study estimates surface elevation changes underneath the mangrove canopy through vegetation filtering and Difference of DEM (DoD) techniques using two epochs of unmanned aerial vehicle (UAV) data carried out during 2016 and 2017. A novel filtering algorithm named Surface estimation from Nearest Elevation and Repetitive Lowering (SNERL) is used to estimate the elevation height underneath the mangrove canopy. Consequently, DoD technique is used to quantify the elevation change rates at the ground surface, which comprise erosion, accretion, and sedimentation. The significant findings showed that region of interest (ROI) 5 experienced the highest volumetric accretion (surface raising) at 0.566 cm3. The most increased erosion (surface lowering) was identified at ROI 8 at \u22122.469 cm3. In contrast, for vertical change average rates, ROI 6 experienced the highest vertical accretion (surface raising) at 1.281 m. In comparison, the most increased vertical erosion (surface lowering) was spotted at ROI 3 at \u22120.568 m. The change detection map and the rates of surface elevation changes at Kilim River enabled authorities to understand the situation thoroughly and indicate the future situation, including its interaction with sea-level rise impacts.<\/jats:p>","DOI":"10.3390\/ijgi11010032","type":"journal-article","created":{"date-parts":[[2022,1,6]],"date-time":"2022-01-06T03:41:32Z","timestamp":1641440492000},"page":"32","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":16,"title":["Surface Elevation Changes Estimation Underneath Mangrove Canopy Using SNERL Filtering Algorithm and DoD Technique on UAV-Derived DSM Data"],"prefix":"10.3390","volume":"11","author":[{"given":"Norhafizi","family":"Mohamad","sequence":"first","affiliation":[{"name":"Geomatics Innovation Research Group (GnG), Faculty of Built Environment and Surveying, Universiti Teknologi Malaysia (UTM), Johor Bahru 81310, Malaysia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Anuar","family":"Ahmad","sequence":"additional","affiliation":[{"name":"Geomatics Innovation Research Group (GnG), Faculty of Built Environment and Surveying, Universiti Teknologi Malaysia (UTM), Johor Bahru 81310, Malaysia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5106-1995","authenticated-orcid":false,"given":"Mohd Faisal Abdul","family":"Khanan","sequence":"additional","affiliation":[{"name":"Geospatial Imaging and Information Research Group (GI2RG), Faculty of Built Environment and Surveying, Universiti Teknologi Malaysia (UTM), Johor Bahru 81310, Malaysia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ami Hassan Md","family":"Din","sequence":"additional","affiliation":[{"name":"Geospatial Imaging and Information Research Group (GI2RG), Faculty of Built Environment and Surveying, Universiti Teknologi Malaysia (UTM), Johor Bahru 81310, Malaysia"},{"name":"Geoscience and Digital Earth Centre (INSTeG), Faculty of Built Environment and Surveying, Universiti Teknologi Malaysia (UTM), Johor Bahru 81310, Malaysia"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2021,12,31]]},"reference":[{"key":"ref_1","unstructured":"Omar, M., Aziz, K., Shamsudin, I., and Raja Barizian, R.S. (2012). Functions and values of mangroves, Status of Mangroves in Peninsular Malaysia."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"878","DOI":"10.3390\/rs3050878","article-title":"Remote sensing of mangrove ecosystems: A review","volume":"3","author":"Kuenzer","year":"2011","journal-title":"Remote Sens."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Mohamad, N., Khanan, M.F.A., Ahmad, A., Din, M., Hassan, A., and Shahabi, H. (2019). Evaluating Water Level Changes at Different Tidal Phases Using UAV Photogrammetry and GNSS Vertical Data. Sensors, 19.","DOI":"10.3390\/s19173778"},{"key":"ref_4","first-page":"012020","article-title":"Spatio-temporal analysis of river morphological changes and erosion detection using very high resolution satellite image","volume":"Volume 169","author":"Mohamad","year":"2018","journal-title":"Proceedings of the 9th IGRSM International Conference and Exhibition on Geospatial & Remote Sensing (IGRSM 2018)"},{"key":"ref_5","unstructured":"Mohamad, N., Khanan, M.F.A., Musliman, I.A., Kadir, W.H.W., Ahmad, A., Rahman, M.Z.A., Jamal, M.H., Zabidi, M., Suaib, N.M., and Zain, R.M. (2017, January 11\u201312). Riverbank erosion mapping using high resolution satellite image and unmanned aerial vehicle (UAV) approach. Proceedings of the 1st International Undergraduate and Postgraduate Students Conference on Marine Science, Technology and Management, Kuala Terengganu, Malaysia."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"14360","DOI":"10.3390\/rs71114360","article-title":"Satellite images for monitoring mangrove cover changes in a fast growing economic region in southern Peninsular Malaysia","volume":"7","author":"Kanniah","year":"2015","journal-title":"Remote Sens."},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Wang, L., Jia, M., Yin, D., and Tian, J. (2019). A review of remote sensing for mangrove forests: 1956\u20132018. Remote Sens. Environ., 231.","DOI":"10.1016\/j.rse.2019.111223"},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Ragia, L., and Krassakis, P. (2019, January 18\u201321). Monitoring the changes of the coastal areas using remote sensing data and geographic information systems. Proceedings of the Seventh International Conference on Remote Sensing and Geoinformation of the Environment (RSCy2019), Paphos, Cyprus.","DOI":"10.1117\/12.2533659"},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Aryastana, P., Ardantha, I.M., and Candrayana, K.W. (2018, January 18). Coastline change analysis and erosion prediction using satellite images. Proceedings of the 3rd Annual Applied Science and Engineering Conference (AASEC 2018), MATEC Web Conference, Bandung, Indonesia.","DOI":"10.1051\/matecconf\/201819713003"},{"key":"ref_10","first-page":"012023","article-title":"Monitoring of shoreline changes using remote sensing (case study: Coastal city of Bandar Abbas)","volume":"Volume 20","author":"Tamassoki","year":"2014","journal-title":"Proceedings of the 7th IGRSM International Conference and Exhibition on Geospatial & Remote Sensing (IGRSM 2018)"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"511","DOI":"10.2112\/SI65-087.1","article-title":"Medium resolution satellite imagery as a tool for monitoring shoreline change\u2019, Case study of the Eastern coast of Ghana","volume":"65","author":"Addo","year":"2013","journal-title":"J. Coast. Res."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"391","DOI":"10.1007\/s10661-008-0366-7","article-title":"Monitoring the changing position of coastlines using aerial and satellite image data: An example from the eastern coast of Trabzon, Turkey","volume":"153","author":"Sesli","year":"2009","journal-title":"Environ. Monit. Assess."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"4115","DOI":"10.1080\/01431160110115979","article-title":"Monitoring coastal erosion at the Black Sea coasts in Turkey using satellite data: A case study at the Lake Terkos, north-west Istanbul","volume":"23","author":"Maktav","year":"2002","journal-title":"Int. J. Remote Sens."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1285","DOI":"10.1080\/19475705.2019.1571533","article-title":"Application of unmanned aircraft system (UAS) for monitoring bank erosion along river corridors","volume":"10","author":"Hamshaw","year":"2019","journal-title":"Geomat. Nat. Hazards Risk"},{"key":"ref_15","first-page":"428","article-title":"Monitoring river morphology and bank erosion using UAV imagery\u2013A case study of the river Bu\u00ebch, Hautes-Alpes, France","volume":"73","author":"Hemmelder","year":"2018","journal-title":"Int. J. Appl. Earth Obs. Geoinf."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"933","DOI":"10.5194\/esurf-6-933-2018","article-title":"Bank erosion processes measured with UAV-SfM along complex banklines of a straight mid-sized river reach","volume":"6","author":"Crosato","year":"2018","journal-title":"Earth Surf. Dyn."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Hamshaw, S.D., Bryce, T., O\u2019Neil Dunne, J., Rizzo, D.M., Frolik, J., Engel, T., and Dewoolkar, M.M. (2017). Quantifying streambank erosion using unmanned aerial systems at site-specific and river network scales. Geotech. Front., 499\u2013508.","DOI":"10.1061\/9780784480458.051"},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Wang, R., Zhang, S., Pu, L., Yang, J., Yang, C., Chen, J., Guan, C., Wang, Q., Chen, D., and Fu, B. (2016). Gully erosion mapping and monitoring at multiple scales based on multi-source remote sensing data of the Sancha River Catchment, Northeast China. ISPRS Int. J. Geo-Inf., 5.","DOI":"10.3390\/ijgi5110200"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"8","DOI":"10.1016\/j.geomorph.2016.06.027","article-title":"Erosion processes in calanchi in the Upper Orcia Valley, Southern Tuscany, Italy based on multitemporal high-resolution terrestrial LiDAR and UAV surveys","volume":"269","author":"Neugirg","year":"2016","journal-title":"Geomorphology"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"27969","DOI":"10.3390\/s151127969","article-title":"Automated identification of river hydromorphological features using UAV high resolution aerial imagery","volume":"15","author":"Casado","year":"2015","journal-title":"Sensors"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"121","DOI":"10.1016\/j.geomorph.2017.12.037","article-title":"Coastal monitoring solutions of the geomorphological response of beach-dune systems using multi-temporal LiDAR datasets (Vend\u00e9e coast, France)","volume":"304","author":"Juigner","year":"2018","journal-title":"Geomorphology"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"195","DOI":"10.1016\/j.geomorph.2016.11.009","article-title":"An evaluation of the effectiveness of low-cost UAVs and structure from motion for geomorphic change detection","volume":"278","author":"Cook","year":"2017","journal-title":"Geomorphology"},{"key":"ref_23","first-page":"265","article-title":"Mapping of coastal landforms and volumetric change analysis in the south west coast of Kanyakumari, South India using remote sensing and GIS techniques","volume":"20","author":"Kaliraj","year":"2017","journal-title":"Egypt. J. Remote Sens. Space Sci."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"12","DOI":"10.1016\/j.apgeog.2016.07.015","article-title":"Application of change detection techniques in geomorphological evolution of coastal areas. Example: Mouth of the River Ebro (period 1957\u20132013)","volume":"75","author":"Gracia","year":"2016","journal-title":"Appl. Geogr."},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Guimar\u00e3es, U.S., Rodrigues, T.W.P., Galo, M.D.L.B.T., and Pamplona, V.M.S. (2014, January 13\u201318). Change detection applied on shorelines in the mouth of Amazon River. Proceedings of the 2014 IEEE Geoscience and Remote Sensing Symposium (IGARSS), Quebec City, QC, Canada.","DOI":"10.1109\/IGARSS.2014.6946891"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"1587","DOI":"10.1109\/LGRS.2013.2262317","article-title":"Geomorphological change detection using object-based feature extraction from multi-temporal LiDAR data","volume":"10","author":"Anders","year":"2013","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1141","DOI":"10.1016\/j.oceaneng.2011.05.006","article-title":"Automatic detection of shoreline change on coastal Ramsar wetlands of Turkey","volume":"38","author":"Kuleli","year":"2011","journal-title":"Ocean Eng."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"945","DOI":"10.1080\/01431160701294679","article-title":"Monitoring geomorphologic changes using Landsat TM and ETM+ data in the Hendijan River delta, southwest Iran","volume":"29","author":"Ghanavati","year":"2008","journal-title":"Int. J. Remote Sens."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"3671","DOI":"10.1080\/01431160500500375","article-title":"Coastal geomorphological and land-use and land-cover study of Sagar Island, Bay of Bengal (India) using remotely sensed data","volume":"27","author":"Jayappa","year":"2006","journal-title":"Int. J. Remote Sens."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"1807","DOI":"10.1016\/j.asej.2017.01.007","article-title":"Vertical accuracy assessment for SRTM and ASTER Digital Elevation Models: A case study of Najran city, Saudi Arabia","volume":"9","author":"Elkhrachy","year":"2018","journal-title":"Ain Shams Eng. J."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"20","DOI":"10.1016\/j.isprsjprs.2016.11.002","article-title":"High-quality seamless DEM generation blending SRTM-1, ASTER GDEM v2 and ICESat\/GLAS observations","volume":"123","author":"Yue","year":"2017","journal-title":"ISPRS J. Photogramm. Remote Sens."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"969","DOI":"10.1080\/17538947.2013.807307","article-title":"Comparison and validation of SRTM and ASTER GDEM for a subtropical landscape in Southeastern China","volume":"7","author":"Jing","year":"2014","journal-title":"Int. J. Digit. Earth"},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Gesch, D.B., Oimoen, M.J., and Evans, G.A. (2014). Accuracy Assessment of the US Geological Survey National Elevation Dataset, and Comparison with Other Large-Area Elevation Datasets: SRTM and ASTER.","DOI":"10.3133\/ofr20141008"},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Forkuor, G., and Maathuis, B. (2012). Comparison of SRTM and ASTER Derived Digital Elevation Models over Two Regions in Ghana-Implications for Hydrological and Environmental Modelling, INTECH Open Access Publisher.","DOI":"10.5772\/28951"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"337","DOI":"10.1080\/08120091003677553","article-title":"Comparison and validation of the recent freely available ASTER-GDEM ver1, SRTM ver4.1 and GEODATA DEM-9S ver3 digital elevation models over Australia","volume":"57","author":"Hirt","year":"2010","journal-title":"Aust. J. Earth Sci."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"106","DOI":"10.1016\/j.geomorph.2009.05.010","article-title":"Combining digital elevation data (SRTM\/ASTER), high resolution satellite imagery (Quickbird) and GIS for geomorphological mapping: A multi-component case study on Mediterranean karst in Central Crete","volume":"112","author":"Siart","year":"2009","journal-title":"Geomorphology"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"4819","DOI":"10.1080\/01431160600835853","article-title":"SRTM vs ASTER elevation products. Comparison for two regions in Crete, Greece","volume":"27","author":"Nikolakopoulos","year":"2006","journal-title":"Int. J. Remote Sens."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"1769","DOI":"10.1002\/esp.4125","article-title":"3-D uncertainty-based topographic change detection with structure-from-motion photogrammetry: Precision maps for ground control and directly georeferenced surveys","volume":"42","author":"James","year":"2017","journal-title":"Earth Surf. Process. Landf."},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"James, M.R., and Robson, S. (2012). Straightforward reconstruction of 3D surfaces and topography with a camera: Accuracy and geoscience application. J. Geophys. Res. Earth Surf., 117.","DOI":"10.1029\/2011JF002289"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"136","DOI":"10.1002\/esp.1886","article-title":"Accounting for uncertainty in DEMs from repeat topographic surveys: Improved sediment budgets","volume":"35","author":"Wheaton","year":"2010","journal-title":"Earth Surf. Process. Landf."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"249","DOI":"10.1002\/esp.483","article-title":"Estimation of erosion and deposition volumes in a large, gravel-bed, Braided River using synoptic remote sensing","volume":"28","author":"Lane","year":"2003","journal-title":"Earth Surf. Process. Landf."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"299","DOI":"10.1016\/S0169-555X(02)00320-3","article-title":"Methodological sensitivity of morphometric estimates of coarse fluvial sediment transport","volume":"53","author":"Brasington","year":"2003","journal-title":"Geomorphology"},{"key":"ref_43","unstructured":"Taylor, J.R. (1997). An Introduction to Error Analysis: The Study of Uncertainties in Physical Measurements, University Science Books. [2nd ed.]."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"522","DOI":"10.1080\/10106049.2016.1265599","article-title":"Comparison of the performances of ground filtering algorithms and DTM generation from a UAV-based point cloud","volume":"33","author":"Yilmaz","year":"2018","journal-title":"Geocarto Int."},{"key":"ref_45","doi-asserted-by":"crossref","unstructured":"Anders, N., Valente, J., Masselink, R., and Keesstra, S. (2019). Comparing Filtering Techniques for Removing Vegetation from UAV-Based Photogrammetric Point Clouds. Drones, 3.","DOI":"10.3390\/drones3030061"},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"99","DOI":"10.1016\/j.measurement.2018.10.013","article-title":"Point cloud filtering on UAV based point cloud","volume":"133","author":"Zeybek","year":"2019","journal-title":"Measurement"},{"key":"ref_47","doi-asserted-by":"crossref","unstructured":"\u0160troner, M., Urban, R., Lidmila, M., Kol\u00e1\u0159, V., and K\u0159emen, T. (2021). Vegetation Filtering of a Steep Rugged Terrain: The Performance of Standard Algorithms and a Newly Proposed Workflow on an Example of a Railway Ledge. Remote Sens., 13.","DOI":"10.3390\/rs13153050"},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"1653","DOI":"10.1061\/(ASCE)ST.1943-541X.0000475","article-title":"Summary review of GPS technology for structural health monitoring","volume":"139","author":"Im","year":"2013","journal-title":"J. Struct. Eng."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"67","DOI":"10.1109\/LGRS.2012.2193113","article-title":"Segmentation of low-cost remote sensing images combining vegetation indices and mean shift","volume":"10","author":"Ponti","year":"2012","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"193","DOI":"10.1016\/S0924-2716(98)00009-4","article-title":"Determination of terrain models in wooded areas with airborne laser scanner data","volume":"53","author":"Kraus","year":"1998","journal-title":"ISPRS J. Photogramm. Remote Sens."},{"key":"ref_51","unstructured":"ESSA (2020, October 15). Geomorphic Change Detection (GCD). Available online: https:\/\/essa.com\/explore-essa\/tools\/geomorphic-change-detection."},{"key":"ref_52","unstructured":"Candido, B.M. (2019). Use of Ground and Air-Based Photogrammetry for Soil Erosion Assessment. [Ph.D. Thesis, Lancaster University]."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"761","DOI":"10.1016\/j.crte.2008.07.008","article-title":"Present-day sea level rise: A synthesis","volume":"340","author":"Cazenave","year":"2008","journal-title":"C. R. Geosci."},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"247","DOI":"10.1016\/j.jseaes.2018.07.034","article-title":"Contemporary sea level rise rates around Malaysia: Altimeter data optimization for assessing coastal impact","volume":"166","author":"Hamid","year":"2018","journal-title":"J. Asian Earth Sci."},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"3452","DOI":"10.1016\/j.asr.2019.02.022","article-title":"Sea level trend over Malaysian seas from multi-mission satellite altimetry and vertical land motion corrected tidal data","volume":"63","author":"Din","year":"2019","journal-title":"Adv. Space Res."}],"container-title":["ISPRS International Journal of Geo-Information"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2220-9964\/11\/1\/32\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T07:56:53Z","timestamp":1760169413000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2220-9964\/11\/1\/32"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,12,31]]},"references-count":55,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2022,1]]}},"alternative-id":["ijgi11010032"],"URL":"https:\/\/doi.org\/10.3390\/ijgi11010032","relation":{},"ISSN":["2220-9964"],"issn-type":[{"value":"2220-9964","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,12,31]]}}}