The Use of Unmanned Aerial Vehicles to Determine Differences in Vegetation Cover: A Tool for Monitoring Coastal Wetland Restoration Schemes
Abstract
:1. Introduction
- Evaluate the potential of using simple vegetation indices, derived from UAV imagery, to characterise differences in vegetation coverage across the site in order to assess site development.
- Assess the relationship between site morphology and marsh vegetation coverage.
- Compare differences in coverage both inside and outside of the MR site.
2. Materials and Methods
2.1. Study Site
2.2. UAV Image Acquisition
2.3. UAV Image Processing and Analysis
3. Results
4. Discussion
4.1. Vegetation Cover and the Influence of Site Morphology
4.2. UAV Approaches as a Tool for Assessing Site Development
4.3. Differences between Restored and Natural Marshes
5. Conclusions
Supplementary Materials
Author Contributions
Funding
Acknowledgments
Conflicts of Interest
References
- Barbier:, E.B.; Hacker, S.D.; Kennedy, C.; Koch, E.W.; Stier, A.C.; Silliman, B.R. The value of estuarine and coastal ecosystem services. Ecol. Monogr. 2011, 81, 169–193. [Google Scholar] [CrossRef]
- Adam, P. Saltmarshes in a time of change. Environ. Conserv. 2002, 29, 39–61. [Google Scholar] [CrossRef]
- Callaway, J.C. The Challenge of Restoring Functioning Salt Marsh Ecosystem. J. Coast. Res. 2005, 24–36. Available online: http://www.jstor.org/stable/25736613 (accessed on 7 December 2020).
- French, P.W. Managed realignment—The developing story of a comparatively new approach to soft engineering. Estuar. Coast. Shelf Sci. 2006, 67, 409–423. [Google Scholar] [CrossRef]
- Mossman, H.L.; Davy, A.J.; Grant, A. Does managed coastal realignment create saltmarshes with ‘equivalent biological characteristics‘ to natural reference sites? J. Appl. Ecol. 2012, 49, 1446–1456. [Google Scholar] [CrossRef]
- Brooks, K.L.; Mossman, H.L.; Chitty, J.L.; Grant, A. Limited Vegetation Development on a Created Salt Marsh Associated with Over-Consolidated Sediments and Lack of Topographic Heterogeneity. Estuaries Coasts 2015, 38, 325–336. [Google Scholar] [CrossRef]
- Spencer, K.L.; Carr, S.J.; Diggens, L.M.; Tempest, J.A.; Morris, M.A.; Harvey, G.L. The impact of pre-restoration land-use and disturbance on sediment structure, hydrology and the sediment geochemical environment in restored saltmarshes. Sci. Total Environ. 2017, 587–588, 47–58. [Google Scholar] [CrossRef] [Green Version]
- Dale, J.; Cundy, A.B.; Spencer, K.L.; Carr, S.J.; Croudace, I.W.; Burgess, H.M.; Nash, D.J. Sediment structure and physicochemical changes following tidal inundation at a large open coast managed realignment site. Sci. Total Environ. 2019, 660, 1419–1432. [Google Scholar] [CrossRef] [Green Version]
- Lawrence, P.J.; Smith, G.R.; Sullivan, M.J.P.; Mossman, H.L. Restored saltmarshes lack the topographic diversity found in natural habitat. Ecol. Eng. 2018, 115, 58–66. [Google Scholar] [CrossRef]
- Dale, J.; Burgess, H.M.; Burnside, N.G.; Kilkie, P.; Nash, D.J.; Cundy, A.B. The evolution of embryonic creek systems in a recently inundated large open coast managed realignment site. Anthr. Coasts 2018, 1, 16–33. [Google Scholar] [CrossRef] [Green Version]
- Dale, J. The Evolution of the Sediment Regime in a Large Open Coast Managed Realignment Site: A Case Study of the Medmerry Managed Realignment Site. Ph.D. Thesis, University of Brighton, Brighton, UK, 2018. [Google Scholar]
- Spencer, K.L.; Harvey, G.L. Understanding system disturbance and ecosystem services in restored saltmarshes: Integrating physical and biogeochemical processes. Estuar. Coast. Shelf Sci. 2012, 106, 23–32. [Google Scholar] [CrossRef]
- Allen, J.R.L. Morphodynamics of Holocene salt marshes: A review sketch from the Atlantic and Southern North Sea coasts of Europe. Quat. Sci. Rev. 2000, 19, 1155–1231. [Google Scholar] [CrossRef]
- Moffett, K.B.; Gorelick, S.M. Alternative stable states of tidal marsh vegetation patterns and channel complexity. Ecohydrology 2016, 9, 1639–1662. [Google Scholar] [CrossRef] [Green Version]
- Strick, R.J.P.; Ashworth, P.J.; Sambrook Smith, G.H.; Nicholas, A.P.; Best, J.L.; Lane, S.N.; Parsons, D.R.; Simpson, C.J.; Unsworth, C.A.; Dale, J. Quantification of bedform dynamics and bedload sediment flux in sandy braided rivers from airborne and satellite imagery. Earth Surf. Process. Landf. 2019, 44, 953–972. [Google Scholar] [CrossRef]
- Lane, S.N.; Westaway, R.M.; Hicks, D.M. Estimation of erosion and deposition volumes in a large, gravel-bed, braided river using synoptic remote sensing. Earth Surf. Process. Landf. 2003, 28, 249–271. [Google Scholar] [CrossRef]
- Long, N.; Millescamps, B.; Guillot, B.; Pouget, F.; Bertin, X. Monitoring the Topography of a Dynamic Tidal Inlet Using UAV Imagery. Remote Sens. 2016, 8, 387. [Google Scholar] [CrossRef] [Green Version]
- Larrinaga, A.R.; Brotons, L. Greenness Indices from a Low-Cost UAV Imagery as Tools for Monitoring Post-Fire Forest Recovery. Drones 2019, 3, 6. [Google Scholar] [CrossRef] [Green Version]
- Fonstad, M.A.; Dietrich, J.T.; Courville, B.C.; Jensen, J.L.; Carbonneau, P.E. Topographic structure from motion: A new development in photogrammetric measurement. Earth Surf. Process. Landf. 2013, 38, 421–430. [Google Scholar] [CrossRef] [Green Version]
- Dale, J.; Burnside, N.G.; Strong, C.J.; Burgess, H.M. The use of small-Unmanned Aerial Systems for high resolution analysis for intertidal wetland restoration schemes. Ecol. Eng. 2020, 143, 105695. [Google Scholar] [CrossRef]
- Veettil, B.K.; Ward, R.D.; Lima, M.D.A.C.; Stankovic, M.; Hoai, P.N.; Quang, N.X. Opportunities for seagrass research derived from remote sensing: A review of current methods. Ecol. Indic. 2020, 117, 106560. [Google Scholar] [CrossRef]
- Villoslada, M.; Bergamo, T.F.; Ward, R.D.; Burnside, N.G.; Joyce, C.B.; Bunce, R.G.H.; Sepp, K. Fine scale plant community assessment in coastal meadows using UAV based multispectral data. Ecol. Indic. 2020, 111, 105979. [Google Scholar] [CrossRef]
- Ward, R.D.; Burnside, N.G.; Joyce, C.B.; Sepp, K. The use of medium point density LiDAR elevation data to determine plant community types in Baltic coastal wetlands. Ecol. Indic. 2013, 33, 96–104. [Google Scholar] [CrossRef]
- Chirol, C.; Haigh, I.D.; Pontee, N.; Thompson, C.E.; Gallop, S.L. Parametrizing tidal creek morphology in mature saltmarshes using semi-automated extraction from lidar. Remote Sens. Environ. 2018, 209, 291–311. [Google Scholar] [CrossRef]
- Sonnentag, O.; Hufkens, K.; Teshera-Sterne, C.; Young, A.M.; Friedl, M.; Braswell, B.H.; Milliman, T.; O’Keefe, J.; Richardson, A.D. Digital repeat photography for phenological research in forest ecosystems. Agric. For. Meteorol. 2012, 152, 159–177. [Google Scholar] [CrossRef]
- Woebbecke, D.M.; Meyer, G.E.; Von Bargen, K.; Mortensen, D.A. Color Indices for Weed Identification Under Various Soil, Residue, and Lighting Conditions. Trans. ASAE 1995, 38, 259–269. [Google Scholar] [CrossRef]
- Guijarro, M.; Pajares, G.; Riomoros, I.; Herrera, P.J.; Burgos-Artizzu, X.P.; Ribeiro, A. Automatic segmentation of relevant textures in agricultural images. Comput. Electron. Agric. 2011, 75, 75–83. [Google Scholar] [CrossRef] [Green Version]
- Motohka, T.; Nasahara, K.N.; Oguma, H.; Tsuchida, S. Applicability of Green-Red Vegetation Index for Remote Sensing of Vegetation Phenology. Remote Sens. 2010, 2, 2369–2387. [Google Scholar] [CrossRef] [Green Version]
- Gitelson, A.A.; Kaufman, Y.J.; Stark, R.; Rundquist, D. Novel algorithms for remote estimation of vegetation fraction. Remote Sens. Environ. 2002, 80, 76–87. [Google Scholar] [CrossRef] [Green Version]
- Xue, J.; Su, B. Significant Remote Sensing Vegetation Indices: A Review of Developments and Applications. J. Sens. 2017, 2017, 1353691. [Google Scholar] [CrossRef] [Green Version]
- Westoby, M.J.; Brasington, J.; Glasser, N.F.; Hambrey, M.J.; Reynolds, J.M. ‘Structure-from-Motion‘ photogrammetry: A low-cost, effective tool for geoscience applications. Geomorphology 2012, 179, 300–314. [Google Scholar] [CrossRef] [Green Version]
- Robinson, M.; Armstrong, A.C. The Extent of Agricultural Field Drainage in England and Wales, 1971–1980. Trans. Inst. Br. Geogr. 1988, 13, 19–28. [Google Scholar] [CrossRef]
- Rodwell, J.S. (Ed.) British Plant Communities: Volume 5—Maritime Communities and Vegetation of Open Habitats; Cambridge University Press: Cambridge, UK, 2001. [Google Scholar]
- Foster, N.M.; Hudson, M.D.; Bray, S.; Nicholls, R.J. Intertidal mudflat and saltmarsh conservation and sustainable use in the UK: A review. J. Environ. Manag. 2013, 126, 96–104. [Google Scholar] [CrossRef] [PubMed]
- Krolik-Root, C.; Stansbury, D.L.; Burnside, N.G. Effective LiDAR-based modelling and visualisation of managed retreat scenarios for coastal planning: An example from the southern UK. Ocean Coast. Manag. 2015, 114, 164–174. [Google Scholar] [CrossRef]
- Howe, A.J.; Rodriguez, J.F.; Spencer, J.; MacFarlane, G.R.; Saintilan, N. Response of estuarine wetlands to reinstatement of tidal flows. Mar. Freshw. Res. 2010, 61, 702–713. [Google Scholar] [CrossRef]
- D‘Alpaos, A.; Lanzoni, S.; Marani, M.; Bonornetto, A.; Cecconi, G.; Rinaldo, A. Spontaneous tidal network formation within a constructed salt marsh: Observations and morphodynamic modelling. Geomorphology 2007, 91, 186–197. [Google Scholar] [CrossRef]
- Burgess, H.; Kilkie, P.; Callaway, T. Understanding the Physical Processes Occurring within a New Coastal Managed Realignment Site, Medmerry, Sussex, UK. In Coastal Management: Changing Coast, Changing Climate, Changing Minds; ICE Publishing: London, UK, 2016. [Google Scholar]
- Dale, J.; Burgess, H.M.; Cundy, A.B. Sedimentation rhythms and hydrodynamics in two engineered environments in an open coast managed realignment site. Mar. Geol. 2017, 383, 120–131. [Google Scholar] [CrossRef] [Green Version]
- Burgess, K.; Pontee, N.; Wilson, T.; Lee, S.C.; Cox, R. Steart coastal management project: Engineering challenges in a hyper-tidal environment. In From Sea to Shore–Meeting the Challenges of the Sea: (Coasts, Marine Structures and Breakwaters 2013); ICE Publishing: London, UK, 2013; pp. 665–674. [Google Scholar]
- Pearce, J.; Khan, S.; Lewis, P. Medmerry Managed Realignment–Sustainable Coastal Management to Gain Multiple Benefits; ICE Publishing: London, UK, 2011. [Google Scholar]
- Dent, D.L.; Downing, E.J.B.; Rogaar, H. Changes in structure of marsh soils following drainage and arable cultivation. J. Soil Sci. 1976, 27, 250–265. [Google Scholar] [CrossRef]
- Tempest, J.A.; Harvey, G.L.; Spencer, K.L. Modified sediments and subsurface hydrology in natural and recreated salt marshes and implications for delivery of ecosystem services. Hydrol. Process. 2015, 29, 2346–2357. [Google Scholar] [CrossRef]
- Strong, C.J.; Burnside, N.G.; Llewellyn, D. The potential of small-Unmanned Aircraft Systems for the rapid detection of threatened unimproved grassland communities using an Enhanced Normalized Difference Vegetation Index. PLoS ONE 2017, 12, e0186193. [Google Scholar] [CrossRef] [Green Version]
- Huete, A.R. Remote sensing for environmental monitoring. In Environmental Monitoring and Characterization; Artiola, J.F., Pepper, I.L., Brusseau, M.L., Eds.; Academic Press: Burlington, MA, USA, 2004; pp. 183–206. [Google Scholar]
- Mafi-Gholami, D.; Zenner, E.K.; Jaafari, A.; Ward, R.D. Modeling multi-decadal mangrove leaf area index in response to drought along the semi-arid southern coasts of Iran. Sci. Total Environ. 2019, 656, 1326–1336. [Google Scholar] [CrossRef]
- Pagès, J.F.; Jenkins, S.R.; Bouma, T.J.; Sharps, E.; Skov, M.W. Opposing Indirect Effects of Domestic Herbivores on Saltmarsh Erosion. Ecosystems 2019, 22, 1055–1068. [Google Scholar] [CrossRef] [Green Version]
- Ford, H.; Garbutt, A.; Jones, L.; Jones, D.L. Grazing management in saltmarsh ecosystems drives invertebrate diversity, abundance and functional group structure. Insect Conserv. Divers. 2013, 6, 189–200. [Google Scholar] [CrossRef] [Green Version]
- Kiehl, K.; Eischeid, I.; Gettner, S.; Walter, J. Impact of different sheep grazing intensities on salt marsh vegetation in northern Germany. J. Veg. Sci. 1996, 7, 99–106. [Google Scholar] [CrossRef]
- Andresen, H.; Bakker, J.P.; Brongers, M.; Heydemann, B.; Irmler, U. Long-term changes of salt marsh communities by cattle grazing. Vegetatio 1990, 89, 137–148. [Google Scholar] [CrossRef]
UAV Property | Value |
---|---|
Images Analysed | 1047 |
No. of GCPs | 6 |
No. of Check Points | 9 |
Orthophotography Resolution (m/pix) | 0.022 |
DSM Resolution (m/pix) | 0.022 |
Reported X Error (m) | 0.001 |
Reported Y Error (m) | <0.001 |
Reported Z Error (m) | <0.001 |
Calculated X RMSE (m) | 0.288 |
Calculated Y RMSE (m) | 0.272 |
Calculated Z RMSE (m) | 0.153 |
Vegetation Indices | Equation | Reference |
---|---|---|
Excess Greenness Index (ExGI) | Larrinaga and Brotons, 2019 [18]; Sonnentag et al., 2012 [25]; Woebbecke et al., 1995 [26]. | |
Green Chromatic Coordinate (GCC) | Sonnentag et al., 2012 [25]. | |
Green Red Vegetation Index (GRVI) | Motohka et al., 2010 [28]; Villoslada et al., 2020 [22]. | |
Visible Atmospherically Resistant Index (VARI) | Gitelson et al., 2002 [29]; Larrinaga and Brotons, 2019 [18]. |
Size (m2) | Elevation (m OD) | ExGI | GCC | GRVI | VARI | ||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Mean | St. dev | Mean | St. dev | Max | Mean | St. dev | Max | Mean | St. dev | Max | Mean | St. dev | Max | ||
Zone 1 | 122,155 | 4.13 | 0.57 | 65.62 | 25.78 | 204 | 0.392 | 0.024 | 0.923 | 0.051 | 0.036 | 0.920 | 0.038 | 0.026 | 0.871 |
Zone 2 | 89,429 | 4.05 | 0.56 | 49.61 | 28.35 | 176 | 0.375 | 0.028 | 0.979 | 0.049 | 0.035 | 0.958 | 0.035 | 0.025 | 0.958 |
Zone 3 | 112,347 | 3.63 | 0.66 | 37.94 | 27.70 | 173 | 0.358 | 0.027 | 0.999 | 0.038 | 0.029 | 0.999 | 0.026 | 0.020 | 0.999 |
Natural Marsh | 292,189 | 3.72 | 1.01 | 54.88 | 34.52 | 217 | 0.377 | 0.036 | 0.999 | 0.047 | 0.038 | 0.999 | 0.073 | 0.057 | 0.999 |
Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. |
© 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
Share and Cite
Dale, J.; Burnside, N.G.; Hill-Butler, C.; Berg, M.J.; Strong, C.J.; Burgess, H.M. The Use of Unmanned Aerial Vehicles to Determine Differences in Vegetation Cover: A Tool for Monitoring Coastal Wetland Restoration Schemes. Remote Sens. 2020, 12, 4022. https://doi.org/10.3390/rs12244022
Dale J, Burnside NG, Hill-Butler C, Berg MJ, Strong CJ, Burgess HM. The Use of Unmanned Aerial Vehicles to Determine Differences in Vegetation Cover: A Tool for Monitoring Coastal Wetland Restoration Schemes. Remote Sensing. 2020; 12(24):4022. https://doi.org/10.3390/rs12244022
Chicago/Turabian StyleDale, Jonathan, Niall G. Burnside, Charley Hill-Butler, Maureen J. Berg, Conor J. Strong, and Heidi M. Burgess. 2020. "The Use of Unmanned Aerial Vehicles to Determine Differences in Vegetation Cover: A Tool for Monitoring Coastal Wetland Restoration Schemes" Remote Sensing 12, no. 24: 4022. https://doi.org/10.3390/rs12244022
APA StyleDale, J., Burnside, N. G., Hill-Butler, C., Berg, M. J., Strong, C. J., & Burgess, H. M. (2020). The Use of Unmanned Aerial Vehicles to Determine Differences in Vegetation Cover: A Tool for Monitoring Coastal Wetland Restoration Schemes. Remote Sensing, 12(24), 4022. https://doi.org/10.3390/rs12244022