Modeling Salt Marsh Vegetation Height Using Unoccupied Aircraft Systems and Structure from Motion
Salt marshes provide important services to coastal ecosystems in the southeastern United States. In many locations, salt marsh habitats are threatened by coastal development and erosion, necessitating large-scale monitoring. Assessing vegetation height across the extent of a marsh can provide a comp...
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| Format: | Article |
| Language: | English |
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MDPI AG
2020-07-01
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| Series: | Remote Sensing |
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| Online Access: | https://www.mdpi.com/2072-4292/12/14/2333 |
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| author | Alexandra E. DiGiacomo Clara N. Bird Virginia G. Pan Kelly Dobroski Claire Atkins-Davis David W. Johnston Justin T. Ridge |
| author_facet | Alexandra E. DiGiacomo Clara N. Bird Virginia G. Pan Kelly Dobroski Claire Atkins-Davis David W. Johnston Justin T. Ridge |
| author_sort | Alexandra E. DiGiacomo |
| collection | DOAJ |
| description | Salt marshes provide important services to coastal ecosystems in the southeastern United States. In many locations, salt marsh habitats are threatened by coastal development and erosion, necessitating large-scale monitoring. Assessing vegetation height across the extent of a marsh can provide a comprehensive analysis of its health, as vegetation height is associated with Above Ground Biomass (AGB) and can be used to track degradation or growth over time. Traditional methods to do this, however, rely on manual measurements of stem heights that can cause harm to the marsh ecosystem. Moreover, manual measurements are limited in scale and are often time and labor intensive. Unoccupied Aircraft Systems (UAS) can provide an alternative to manual measurements and generate continuous results across a large spatial extent in a short period of time. In this study, a multirotor UAS equipped with optical Red Green Blue (RGB) and multispectral sensors was used to survey five salt marshes in Beaufort, North Carolina. Structure-from-Motion (SfM) photogrammetry of the resultant imagery allowed for continuous modeling of the entire marsh ecosystem in a three-dimensional space. From these models, vegetation height was extracted and compared to ground-based manual measurements. Vegetation heights generated from UAS data consistently under-predicted true vegetation height proportionally and a transformation was developed to predict true vegetation height. Vegetation height may be used as a proxy for Above Ground Biomass (AGB) and contribute to blue carbon estimates, which describe the carbon sequestered in marine ecosystems. Employing this transformation, our results indicate that UAS and SfM are capable of producing accurate assessments of salt marsh health via consistent and accurate vegetation height measurements. |
| first_indexed | 2024-03-10T18:20:17Z |
| format | Article |
| id | doaj.art-dc5f873407a74832a16025866ce80405 |
| institution | Directory Open Access Journal |
| issn | 2072-4292 |
| language | English |
| last_indexed | 2024-03-10T18:20:17Z |
| publishDate | 2020-07-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Remote Sensing |
| spelling | doaj.art-dc5f873407a74832a16025866ce804052023-11-20T07:24:30ZengMDPI AGRemote Sensing2072-42922020-07-011214233310.3390/rs12142333Modeling Salt Marsh Vegetation Height Using Unoccupied Aircraft Systems and Structure from MotionAlexandra E. DiGiacomo0Clara N. Bird1Virginia G. Pan2Kelly Dobroski3Claire Atkins-Davis4David W. Johnston5Justin T. Ridge6Division of Marine Science and Conservation, Nicholas School of the Environment, Duke University Marine Laboratory, 135 Duke Marine Lab Rd, Beaufort, NC 28516, USADivision of Marine Science and Conservation, Nicholas School of the Environment, Duke University Marine Laboratory, 135 Duke Marine Lab Rd, Beaufort, NC 28516, USADivision of Marine Science and Conservation, Nicholas School of the Environment, Duke University Marine Laboratory, 135 Duke Marine Lab Rd, Beaufort, NC 28516, USADivision of Marine Science and Conservation, Nicholas School of the Environment, Duke University Marine Laboratory, 135 Duke Marine Lab Rd, Beaufort, NC 28516, USADivision of Marine Science and Conservation, Nicholas School of the Environment, Duke University Marine Laboratory, 135 Duke Marine Lab Rd, Beaufort, NC 28516, USADivision of Marine Science and Conservation, Nicholas School of the Environment, Duke University Marine Laboratory, 135 Duke Marine Lab Rd, Beaufort, NC 28516, USADivision of Marine Science and Conservation, Nicholas School of the Environment, Duke University Marine Laboratory, 135 Duke Marine Lab Rd, Beaufort, NC 28516, USASalt marshes provide important services to coastal ecosystems in the southeastern United States. In many locations, salt marsh habitats are threatened by coastal development and erosion, necessitating large-scale monitoring. Assessing vegetation height across the extent of a marsh can provide a comprehensive analysis of its health, as vegetation height is associated with Above Ground Biomass (AGB) and can be used to track degradation or growth over time. Traditional methods to do this, however, rely on manual measurements of stem heights that can cause harm to the marsh ecosystem. Moreover, manual measurements are limited in scale and are often time and labor intensive. Unoccupied Aircraft Systems (UAS) can provide an alternative to manual measurements and generate continuous results across a large spatial extent in a short period of time. In this study, a multirotor UAS equipped with optical Red Green Blue (RGB) and multispectral sensors was used to survey five salt marshes in Beaufort, North Carolina. Structure-from-Motion (SfM) photogrammetry of the resultant imagery allowed for continuous modeling of the entire marsh ecosystem in a three-dimensional space. From these models, vegetation height was extracted and compared to ground-based manual measurements. Vegetation heights generated from UAS data consistently under-predicted true vegetation height proportionally and a transformation was developed to predict true vegetation height. Vegetation height may be used as a proxy for Above Ground Biomass (AGB) and contribute to blue carbon estimates, which describe the carbon sequestered in marine ecosystems. Employing this transformation, our results indicate that UAS and SfM are capable of producing accurate assessments of salt marsh health via consistent and accurate vegetation height measurements.https://www.mdpi.com/2072-4292/12/14/2333<i>Spartina alterniflora</i>salt marshmonitoringunoccupied aircraft systemsabove ground biomass (AGB)vegetation height |
| spellingShingle | Alexandra E. DiGiacomo Clara N. Bird Virginia G. Pan Kelly Dobroski Claire Atkins-Davis David W. Johnston Justin T. Ridge Modeling Salt Marsh Vegetation Height Using Unoccupied Aircraft Systems and Structure from Motion Remote Sensing <i>Spartina alterniflora</i> salt marsh monitoring unoccupied aircraft systems above ground biomass (AGB) vegetation height |
| title | Modeling Salt Marsh Vegetation Height Using Unoccupied Aircraft Systems and Structure from Motion |
| title_full | Modeling Salt Marsh Vegetation Height Using Unoccupied Aircraft Systems and Structure from Motion |
| title_fullStr | Modeling Salt Marsh Vegetation Height Using Unoccupied Aircraft Systems and Structure from Motion |
| title_full_unstemmed | Modeling Salt Marsh Vegetation Height Using Unoccupied Aircraft Systems and Structure from Motion |
| title_short | Modeling Salt Marsh Vegetation Height Using Unoccupied Aircraft Systems and Structure from Motion |
| title_sort | modeling salt marsh vegetation height using unoccupied aircraft systems and structure from motion |
| topic | <i>Spartina alterniflora</i> salt marsh monitoring unoccupied aircraft systems above ground biomass (AGB) vegetation height |
| url | https://www.mdpi.com/2072-4292/12/14/2333 |
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