A comparative analysis of conventional and emerging methods for characterizing coastal morphology and change

Small islands and coastal areas are threatened by the negative impacts of climate change. Sea-level rise, increased storm event and frequency, and other coastal hazards are expected to impact infrastructure, settlements, and facilities that support the livelihood of coastal communities. In addition, small islands and coastal communities are often considered to lack the capacity to properly anticipate and adapt to a quickly changing climate. Proper coastal adaptation requires a number of key components including data collection, monitoring and evaluation. This thesis sought to evaluate two methodologies of data collection and monitoring on Prince Edward Island, Canada: one low cost method using terrestrial peg line measurement; and two, the use of low altitude small Unmanned Aerial Vehicles (UAvs) to create high resolution orthomosaics and digital surface models for coastal assessment. Considerations of cost, agility and accuracy of the research methods are made throughout the thesis with an intended application to a long-term monitoring program that can be adopted by other small island and coastal communities around the world interested in improving their resiliency and ability to adapt to climate change.\nAn historical terrestrial measurement method was employed on Prince Edward Island by the Department of Community and Cultural Affairs Marine Environment Section in 1984 but abandoned several years later in the early 1990s. This thesis investigated this method through re-measurement and study of old log books and revealed several inadequacies. Improvements to the historical monitoring method are made through the resurrection and establishment of 74 erosion measuring locations across Prince Edward Island during the 2014 and 2015 field seasons. Measurement of these 74 cliff and bluff coastal environments resulted in an average annual loss of 0.46 m with a single largest loss of 2.69 m. This method is limited by the type of data collection but provides a good starting point for coastal communities with limited knowledge and expertise in the field to begin understanding and quantifying coastal change. Recent developments in Unmanned Aerial Vehicle technology have led to a wide-spread interest in using the technology across many industries and fields of study. A major advantage of using UAVs is their ability to efficiently collect high resolution orthomosaics and elevation models at a fine temporal scale for coastal assessments. This thesis utilized two UAV systems at a study site in North Lake, Prince Edward Island, Canada - a fixed wing system by PrecisionHawk, and a quadcopter by 3DRobotics - and conducted a comparative analysis to determine the best platform for the application to coastal data collection and monitoring. Results found consistently improved performance of the quadcopter versus the fixed wing, including accuracy, a lower upfront cost, and the ability to perform to expectation in high sustained winds. Some results include an image marker to ground control point difference of 0.10 m for the fixed wing and 0.03 m for the quadcopter. The quadcopter showed better results when comparing elevations to a survey grade GPS survey of the study site, and coastal delineations of the orthomosaics showed a slight improvement using the quadcopter. This comparative analysis showed the real possibility of accurately representing a coastal cliff or bluff environment using UAV technology that can be monitored to detect annual change. The ability of UAVs to cost-effectively and accurately produce data rich products leads to the conclusion that the technology provides a realistic alternative to traditional monitoring methods and has great implications for the adoption to monitor coastal environments of small islands and coastal communities.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.