Multi-decadal change detection of coastal dune landscapes using different supervised image classification algorithms

Namibia’s coastal dune systems, vital to biodiversity, tourism, and coastal protection, are increasingly threatened by climate change and anthropogenic forces. This study investigates changes in these dynamic and fragile landscapes over a 30-year period (1994-2024) by comparing the performance of f...

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Main Authors: Ryan Theodore BENADE, Aune KAMOSHO, Lutobohile Ivonne MAKANDO, Oluibukun Gbenga AJAYI
Format: Article
Language:English
Published: Society of Land Measurements and Cadastre from Transylvania (SMTCT) 2025-07-01
Series:Nova Geodesia
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Online Access:https://novageodesia.ro/index.php/ng/article/view/378
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author Ryan Theodore BENADE
Aune KAMOSHO
Lutobohile Ivonne MAKANDO
Oluibukun Gbenga AJAYI
author_facet Ryan Theodore BENADE
Aune KAMOSHO
Lutobohile Ivonne MAKANDO
Oluibukun Gbenga AJAYI
author_sort Ryan Theodore BENADE
collection DOAJ
description Namibia’s coastal dune systems, vital to biodiversity, tourism, and coastal protection, are increasingly threatened by climate change and anthropogenic forces. This study investigates changes in these dynamic and fragile landscapes over a 30-year period (1994-2024) by comparing the performance of four supervised image classification algorithms: Maximum Likelihood, Minimum Distance, Spectral Angle Mapping, and Random Forest. Landsat 5 and 8 images for four epochs (1994, 2004, 2014, 2024) were pre-processed in QGIS, and classification was performed using the Semi-Automatic Classification Plugin (SCP). Virtual rasters were generated, and training samples were used to classify dune features and surrounding land cover types. Classification accuracy was assessed using 100 randomly generated reference points per year to ensure reliability and consistency. Results revealed Random Forest as the most accurate algorithm, outperforming the others in capturing spectral variability and complex land cover transitions, particularly near rapidly expanding urban centres like Swakopmund and Walvis Bay. The classification maps revealed notable spatial and temporal changes, including dune displacement, urban encroachment and fluctuations in bare rock coverage. This study addresses the current gap in long-term dune monitoring using advanced classification methods and contributes data-driven insights for conservation planning, environmental management and sustainable land use in Namibia’s coastal areas.
format Article
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publishDate 2025-07-01
publisher Society of Land Measurements and Cadastre from Transylvania (SMTCT)
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spelling doaj-art-2e377e208b15433fb23938457eaf8fde2025-08-23T10:53:39ZengSociety of Land Measurements and Cadastre from Transylvania (SMTCT)Nova Geodesia2810-27542025-07-015310.55779/ng53378Multi-decadal change detection of coastal dune landscapes using different supervised image classification algorithmsRyan Theodore BENADE0Aune KAMOSHO1Lutobohile Ivonne MAKANDO2Oluibukun Gbenga AJAYI3Namibia University of Science and Technology, Faculty of Engineering and Built Environment, Department of Land and Spatial Sciences, Windhoek; International University of Management, Faculty of Environmental Management and Sustainability Sciences (FEMSS), Windhoek, NamibiaNamibia University of Science and Technology, Faculty of Engineering and Built Environment, Department of Land and Spatial Sciences, WindhoekNamibia University of Science and Technology, Faculty of Engineering and Built Environment, Department of Land and Spatial Sciences, WindhoekNamibia University of Science and Technology, Faculty of Engineering and Built Environment, Department of Land and Spatial Sciences, Windhoek, Namibia; University of Pretoria, Faculty of Natural and Agricultural Science, Department of Geography, Geoinformatics and Meteorology, Pretoria, South Africa; INTI International University, Nilai, Malaysia Namibia’s coastal dune systems, vital to biodiversity, tourism, and coastal protection, are increasingly threatened by climate change and anthropogenic forces. This study investigates changes in these dynamic and fragile landscapes over a 30-year period (1994-2024) by comparing the performance of four supervised image classification algorithms: Maximum Likelihood, Minimum Distance, Spectral Angle Mapping, and Random Forest. Landsat 5 and 8 images for four epochs (1994, 2004, 2014, 2024) were pre-processed in QGIS, and classification was performed using the Semi-Automatic Classification Plugin (SCP). Virtual rasters were generated, and training samples were used to classify dune features and surrounding land cover types. Classification accuracy was assessed using 100 randomly generated reference points per year to ensure reliability and consistency. Results revealed Random Forest as the most accurate algorithm, outperforming the others in capturing spectral variability and complex land cover transitions, particularly near rapidly expanding urban centres like Swakopmund and Walvis Bay. The classification maps revealed notable spatial and temporal changes, including dune displacement, urban encroachment and fluctuations in bare rock coverage. This study addresses the current gap in long-term dune monitoring using advanced classification methods and contributes data-driven insights for conservation planning, environmental management and sustainable land use in Namibia’s coastal areas. https://novageodesia.ro/index.php/ng/article/view/378applied remote sensingchange detectioncoastal dunesenvironmental monitoringnature conservationsupervised classification
spellingShingle Ryan Theodore BENADE
Aune KAMOSHO
Lutobohile Ivonne MAKANDO
Oluibukun Gbenga AJAYI
Multi-decadal change detection of coastal dune landscapes using different supervised image classification algorithms
Nova Geodesia
applied remote sensing
change detection
coastal dunes
environmental monitoring
nature conservation
supervised classification
title Multi-decadal change detection of coastal dune landscapes using different supervised image classification algorithms
title_full Multi-decadal change detection of coastal dune landscapes using different supervised image classification algorithms
title_fullStr Multi-decadal change detection of coastal dune landscapes using different supervised image classification algorithms
title_full_unstemmed Multi-decadal change detection of coastal dune landscapes using different supervised image classification algorithms
title_short Multi-decadal change detection of coastal dune landscapes using different supervised image classification algorithms
title_sort multi decadal change detection of coastal dune landscapes using different supervised image classification algorithms
topic applied remote sensing
change detection
coastal dunes
environmental monitoring
nature conservation
supervised classification
url https://novageodesia.ro/index.php/ng/article/view/378
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