The world’s coastlines are changing at a rapid pace due to climate change, rising sea levels, and increased coastal erosion. It’s crucial that we monitor and track these changes so that we can mitigate their effects on our environment and communities. One way to do this is through drone mapping and surveying.
What is Drone Mapping and Surveying?
Drone mapping and surveying is the process of using drones or unmanned aerial vehicles (UAVs) to capture high-resolution aerial imagery and data for various purposes, like collecting information about topography, land use, vegetation, and infrastructure. The data collected through drone mapping and surveying can be used for planning, modeling, analysis, and decision-making in various industries, like construction, agriculture, mining, forestry, and environmental conservation.
Drones equipped with advanced sensors and cameras, such as LiDAR, photogrammetry, and multispectral imaging, can capture detailed and accurate 3D models, maps, and digital elevation models (DEMs) of the surveyed areas. This data can be processed using software tools like GIS, CAD, and machine learning algorithms to extract valuable insights and patterns.
Drone mapping and surveying is becoming more popular and affordable, with many companies offering drone surveying services for different applications. However, drone mapping and surveying in coastal areas present unique challenges and opportunities.
Why Use Drone Mapping and Surveying in Coastal Areas?
Coastal areas are dynamic and complex environments, with various natural and human-made features that interact and evolve over time, such as beaches, dunes, cliffs, wetlands, ports, and cities. Monitoring and surveying coastal areas regularly require significant resources, time, and expertise, especially in remote or hazardous locations. Drones can provide a more efficient, accurate, and safe way to survey these areas while reducing costs and risks.
Drones can capture high-resolution aerial imagery and data of the coastline, even in hard-to-reach areas. They can fly at different altitudes and angles, producing different types of data, like orthomosaics, point clouds, and thermal imagery. Drones can also fly at low tide to capture the intertidal zone, where many coastal habitats and species are found but often neglected in traditional surveying methods.
Using drones for coastal mapping and surveying can provide various benefits, including:
- High-resolution and up-to-date imagery and data of coastal areas
- Improved accuracy and precision in mapping and surveying
- Closer engagement with coastal features and processes
- Faster and safer data collection in hazardous or inaccessible areas
- Reduced environmental impact and disturbance in sensitive areas
- Cost and time efficiency in data collection and processing
What are the Challenges of Drone Mapping and Surveying in Coastal Areas?
Drone mapping and surveying in coastal areas are not without challenges. The dynamic and varied nature of coastal environments can pose technical, ethical, and regulatory challenges that should be addressed to ensure the safety and effectiveness of the surveying process.
Technical Challenges
The technical challenges of drone mapping and surveying in coastal areas include:
- Weather and wind conditions that can affect drone stability and performance
- Water reflections, glares, and waves that can distort or obscure aerial imagery
- Obstacles like buildings, trees, rocks, and birds that can interfere with drone flights or damage the equipment
- The need for high-accuracy geolocation of the drone and the surveyed area to ensure accurate data processing and analysis
Ethical Challenges
The ethical challenges of drone mapping and surveying in coastal areas include:
- The potential invasion of privacy for people living near or using the surveyed areas
- The potential disturbance or harm to wildlife and habitats, especially protected or endangered species
- The potential use of drones for illegal or harmful activities, like smuggling, terrorism, or surveillance
Regulatory Challenges
The regulatory challenges of drone mapping and surveying in coastal areas include:
- The need to obtain proper permits and approvals from relevant authorities, like aviation and coastal management agencies, and comply with local regulations and laws
- The need to ensure the safety of drone flights and avoid collisions with other aircraft or people
- The need to protect the intellectual property of the collected data and ensure data privacy and security
How Can Drones Monitor Erosion and Sea Level Rise?
One of the main applications of drone mapping and surveying in coastal areas is monitoring erosion and sea level rise. Erosion is the natural process of the wearing away of the land surface by the action of water, wind, and other external forces. However, human activities like coastal development, mining, and pollution can accelerate erosion and cause significant damage to the coastlines, reducing their ability to protect against storms and flooding.
Sea level rise is the gradual increase in the average sea level caused by the melting of ice sheets and glaciers and the thermal expansion of seawater due to global warming. Sea level rise can intensify coastal erosion and flooding, leading to the loss of habitats, infrastructure, and lives.
Monitoring erosion and sea level rise in coastal areas is crucial for managing and adapting to their impacts and developing sustainable coastal management plans. Drones can provide high-resolution and frequent aerial data that can help detect, measure, and visualize changes in the areas of interest.
There are several ways that drones can monitor erosion and sea level rise in coastal areas, including:
Photogrammetry and LiDAR Mapping
Drones equipped with photogrammetry or LiDAR sensors can capture high-resolution aerial images and 3D models of the coastline, including the beach, dunes, cliffs, and other structures. The models can be compared over time to identify changes in the elevations, volumes, and areas of interest. This method can detect subtle changes that may not be visible to the naked eye and break down changes by sub-areas.
Orthomosaic Mapping
Drones can capture multiple overlapping aerial images of the coastline and stitch them together to create a high-resolution orthomosaic map. Orthomosaic maps can provide an accurate and up-to-date view of the coastline and highlight changes over time. This method produces a picture of the surveyed area or the coastline, allowing you to make intersubjective comparisons between different times or places.
Aerial Thermal Imaging
Drones equipped with thermal sensors can capture thermal images of the coastline. Thermal imaging can detect variations in the temperature of the water and the ground, which can indicate changes in the water depth or the soil moisture content. This method is not as accurate as photogrammetry or LiDAR mapping, but it can identify hotspots of water or the beach very effectively to highlight erosion or flooding.
Point Cloud analysis
Using drone data, high accuracy point cloud data can be generated. Using advanced analysis, algorithms can measures subtle changes such as the removal of buildings, soil loss, or even tectonic uplift. This data can help predict future land change and higher insight into the area’s subsidence or uplift rates.
Real-Life Examples of Drone Mapping and Surveying in Coastal Areas
Drone mapping and surveying in coastal areas have been applied in various real-life examples worldwide. Here are some of these examples:
Coastal Erosion and Flooding Monitoring in Florida, USA
Florida’s Gulf Coast is one of the most vulnerable areas to coastal erosion and flooding, with significant impacts on the local economy and environment. The University of Florida’s GeoPlan Center used drones to conduct a series of drone flights along the coastline to capture high-resolution aerial imagery and produce orthomosaic maps and digital elevation models. The data collected helped detect and quantify the changes in the coastline, including the receding beach, changes in the dunes, and the encroachment of the sea. The data was used to develop a web-based application that can visualize the impacts of different sea level rise scenarios on the coastlines and assist in developing adaptation strategies. (Source: University of Florida)
Intertidal Habitat Mapping in the UK
The UK’s Joint Nature Conservation Committee (JNCC) used drones to survey the intertidal zone of the eastern coast of England, covering over 650 square kilometers of saltmarshes and mudflats. The drones captured thousands of aerial images and generated high-resolution orthomosaic and digital terrain models of the surveyed areas. The data collected helped identify over 30 distinct intertidal habitats and their distribution, providing a new and detailed understanding of the coastline and its ecological importance. The data was used to update and enhance the UK’s coastal habitat classification system and assist in the management and conservation of the surveyed areas. (Source: JNCC)
Coastal Mapping and Monitoring in Mexico
The Mexican National Institute of Ecology and Climate Change (INECC) used drones to survey the coastline of the Yucatán Peninsula in southeastern Mexico, which is affected by erosion, storms, and rising sea levels. The drones captured aerial imagery and LiDAR data of the coastline, producing high-resolution 3D models and digital elevation models. The data was used to analyze the changes in the coastline, including the erosion of the beaches and the retreat of the mangroves and sand dunes, and develop strategies to manage and adapt to these changes. The data was also shared with local communities, researchers, and decision-makers to increase their awareness and involvement in coastal management. (Source: INECC)
Conclusion
Drone mapping and surveying in coastal areas are becoming more important and accessible as coastal areas undergo rapid changes due to natural and human-induced factors. Drones can provide high-resolution and frequent aerial data that can help monitor and visualize these changes and support better decision-making and management in various sectors. However, drone mapping and surveying in coastal areas present unique challenges that need to be addressed to ensure the safety and effectiveness of the surveying process.
The real-life examples of drone mapping and surveying in coastal areas show the potential and benefits of this technology in supporting coastal management and conservation, from monitoring erosion and sea level rise to understanding and protecting coastal habitats and ecosystems. As drones continue to evolve and improve, so will their applications in coastal areas, helping us better understand and protect our coastlines and the communities and ecosystems that rely on them.
