Overview
James is an environmental scientist using remote sensing and spatial analysis techniques to monitor environmental change. His work has spanned multiple spatial and temporal scales, ranging from the investigation of global changes in vegetation dynamics and night time lighting using satellite data products to developing new methodologies for environmental monitoring at very fine spatial scales with drone and kite aerial photography techniques.
He joined the University of Exeter in 2011, working as a geographical information system (GIS) and remote sensing technician in Professor Kevin Gaston’s research group for three years. Prior to this he was a research assistant working with Dr. Nathalie Pettorelli at the Institute of Zoology in London. It was here that he developed a keen interest in using large remote sensing datasets to quantify environmental changes.
In 2014, James was awarded a NERC funded studentship titled “Coastal eye – monitoring coastal environments using a lightweight drone” from the GW4+ Doctoral Training Partnership. He is currently developing robust techniques using drone and kite aerial photography surveys across the land-sea interface at the coast. His current study systems include coastal dunes, seagrass meadows and coral reefs.
Career & Qualifications
- 2019-Present Postdoctoral Research Fellow (University of Exeter)
- 2014-2018 PhD (University of Exeter)
- 2011-2014 Research Technician (University of Exeter)
- 2010-2011 Research Assistant (Institute of Zoology, Zoological Society of London)
- 2007-2010 BSc Geography with Ecology (University of Sussex)
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Publications
Key publications | Publications by category | Publications by year
Publications by year
2019
Duffy J (2019). Coastal Eye: Monitoring Coastal Environments Using Lightweight Drones.
Abstract:
Coastal Eye: Monitoring Coastal Environments Using Lightweight Drones
Monitoring coastal environments is a challenging task. This is because of both the logistical demands involved with in-situ data collection and the dynamic nature of the coastal zone, where multiple processes operate over varying spatial and temporal scales. Remote sensing products derived from spaceborne and airborne platforms have proven highly useful in the monitoring of coastal ecosystems, but often they fail to capture fine scale processes and there remains a lack of cost-effective and flexible methods for coastal monitoring at these scales. Proximal sensing technology such as lightweight drones and kites has greatly improved the ability to capture fine spatial resolution data at user-dictated visit times. These approaches are democratising, allowing researchers and managers to collect data in locations and at defined times themselves. In this thesis I develop our scientific understanding of the application of proximal sensing within coastal environments. The two critical review pieces consolidate disparate information on the application of kites as a proximal sensing platform, and the often overlooked hurdles of conducting drone operations in challenging environments. The empirical work presented then tests the use of this technology in three different coastal environments spanning the land-sea interface. Firstly, I use kite aerial photography and uncertainty-assessed structure-from-motion multi-view stereo (SfM-MVS) processing to track changes in coastal dunes over time. I report that sub-decimetre changes (both erosion and accretion) can be detected with this methodology. Secondly, I used lightweight drones to capture fine spatial resolution optical data of intertidal seagrass meadows. I found that estimations of plant cover were more similar to in-situ measures in sparsely populated than densely populated meadows. Lastly, I developed a novel technique utilising lightweight drones and SfM-MVS to measure benthic structural complexity in tropical coral reefs. I found that structural complexity measures were obtainable from SfM-MVS derived point clouds, but that the technique was influenced by glint type artefacts in the image data. Collectively, this work advances the knowledge of proximal sensing in the coastal zone, identifying both the strengths and weaknesses of its application across several ecosystems.
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