Tracking the Dynamics of Salt Marsh Including Mixed-Vegetation Zones Employing Sentinel-1 and Sentinel-2 Time-Series Images

Salt marshes, as one of the most productive ecosystems on earth, have experienced fragmentation, degradation, and losses due to the impacts of climate change and human overexploitation. Accurate monitoring of vegetation distribution and composition is crucial for salt marsh protection. However, achi...

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Main Authors: Yujun Yi, Kebing Chen, Jiaxin Xu, Qiyong Luo
Format: Article
Language:English
Published: MDPI AG 2024-12-01
Series:Remote Sensing
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Online Access:https://www.mdpi.com/2072-4292/17/1/56
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author Yujun Yi
Kebing Chen
Jiaxin Xu
Qiyong Luo
author_facet Yujun Yi
Kebing Chen
Jiaxin Xu
Qiyong Luo
author_sort Yujun Yi
collection DOAJ
description Salt marshes, as one of the most productive ecosystems on earth, have experienced fragmentation, degradation, and losses due to the impacts of climate change and human overexploitation. Accurate monitoring of vegetation distribution and composition is crucial for salt marsh protection. However, achieving accurate mapping has posed a challenge. Leveraging the high spatiotemporal resolution of the Sentinel series data, this study developed a method for high-accuracy mapping based on monthly changes across the vegetation life cycle, utilizing the random forest algorithm. This method was applied to identify <i>Phragmites australis</i>, <i>Suaeda salsa</i>, <i>Spartina alterniflora</i>, and the mixed-vegetation zones of <i>Tamarix chinensis</i> in the Yellow River Delta, and to analyze the key features of the model. The results indicate that: (1) integrating Sentinel-1 and Sentinel-2 satellite data achieved superior mapping accuracy (OA = 90.7%) compared to using either satellite individually; (2) the inclusion of SAR data significantly enhanced the classification accuracy within the mixed-vegetation zone, with “SAR<sub>divi</sub>” in July emerging as the pivotal distinguishing feature; and (3) the overall extent of salt marsh vegetation in the Yellow River Delta remained relatively stable from 2018 to 2022, with the largest area recorded in 2020 (265.69 km<sup>2</sup>). These results demonstrate the robustness of integrating Sentinel-1 and Sentinel-2 features for mapping salt marsh, particularly in complex mixed-vegetation zones. Such insights offer valuable guidance for the conservation and management of salt marsh ecosystems.
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spelling doaj-art-84f89349dd0442cab071636546c5e8b42025-01-10T13:20:06ZengMDPI AGRemote Sensing2072-42922024-12-011715610.3390/rs17010056Tracking the Dynamics of Salt Marsh Including Mixed-Vegetation Zones Employing Sentinel-1 and Sentinel-2 Time-Series ImagesYujun Yi0Kebing Chen1Jiaxin Xu2Qiyong Luo3State Key Laboratory of Water Environment Simulation, Beijing Normal University, Beijing 100875, ChinaSchool of Environment, Beijing Normal University, Beijing 100875, ChinaSchool of Environment, Beijing Normal University, Beijing 100875, ChinaSchool of Environment, Beijing Normal University, Beijing 100875, ChinaSalt marshes, as one of the most productive ecosystems on earth, have experienced fragmentation, degradation, and losses due to the impacts of climate change and human overexploitation. Accurate monitoring of vegetation distribution and composition is crucial for salt marsh protection. However, achieving accurate mapping has posed a challenge. Leveraging the high spatiotemporal resolution of the Sentinel series data, this study developed a method for high-accuracy mapping based on monthly changes across the vegetation life cycle, utilizing the random forest algorithm. This method was applied to identify <i>Phragmites australis</i>, <i>Suaeda salsa</i>, <i>Spartina alterniflora</i>, and the mixed-vegetation zones of <i>Tamarix chinensis</i> in the Yellow River Delta, and to analyze the key features of the model. The results indicate that: (1) integrating Sentinel-1 and Sentinel-2 satellite data achieved superior mapping accuracy (OA = 90.7%) compared to using either satellite individually; (2) the inclusion of SAR data significantly enhanced the classification accuracy within the mixed-vegetation zone, with “SAR<sub>divi</sub>” in July emerging as the pivotal distinguishing feature; and (3) the overall extent of salt marsh vegetation in the Yellow River Delta remained relatively stable from 2018 to 2022, with the largest area recorded in 2020 (265.69 km<sup>2</sup>). These results demonstrate the robustness of integrating Sentinel-1 and Sentinel-2 features for mapping salt marsh, particularly in complex mixed-vegetation zones. Such insights offer valuable guidance for the conservation and management of salt marsh ecosystems.https://www.mdpi.com/2072-4292/17/1/56salt marshmixed-vegetation zonesremote sensingrandom forestYellow River DeltaSentinel satellite
spellingShingle Yujun Yi
Kebing Chen
Jiaxin Xu
Qiyong Luo
Tracking the Dynamics of Salt Marsh Including Mixed-Vegetation Zones Employing Sentinel-1 and Sentinel-2 Time-Series Images
Remote Sensing
salt marsh
mixed-vegetation zones
remote sensing
random forest
Yellow River Delta
Sentinel satellite
title Tracking the Dynamics of Salt Marsh Including Mixed-Vegetation Zones Employing Sentinel-1 and Sentinel-2 Time-Series Images
title_full Tracking the Dynamics of Salt Marsh Including Mixed-Vegetation Zones Employing Sentinel-1 and Sentinel-2 Time-Series Images
title_fullStr Tracking the Dynamics of Salt Marsh Including Mixed-Vegetation Zones Employing Sentinel-1 and Sentinel-2 Time-Series Images
title_full_unstemmed Tracking the Dynamics of Salt Marsh Including Mixed-Vegetation Zones Employing Sentinel-1 and Sentinel-2 Time-Series Images
title_short Tracking the Dynamics of Salt Marsh Including Mixed-Vegetation Zones Employing Sentinel-1 and Sentinel-2 Time-Series Images
title_sort tracking the dynamics of salt marsh including mixed vegetation zones employing sentinel 1 and sentinel 2 time series images
topic salt marsh
mixed-vegetation zones
remote sensing
random forest
Yellow River Delta
Sentinel satellite
url https://www.mdpi.com/2072-4292/17/1/56
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AT jiaxinxu trackingthedynamicsofsaltmarshincludingmixedvegetationzonesemployingsentinel1andsentinel2timeseriesimages
AT qiyongluo trackingthedynamicsofsaltmarshincludingmixedvegetationzonesemployingsentinel1andsentinel2timeseriesimages