A citizen science initiative that originated in Australia arrives in Galicia thanks to the researcher from the Geological Oceanography and Biogeochemistry group (XM1, CIM-UVigo) Rita González Villanueva. With the name CoastSnap, the project, already active in 16 countries, will unite scientific communities and citizens from all continents to try to monitor beaches and coastal dynamics by obtaining data through photographs sent by visitors to the sand dunes.
In Galicia, monitoring points are operating on the beaches of Rodas, on the Cíes Islands; Agrelo, in Bueu; A Lanzada, in O Grove and Area Maior, in Muros. CIM researcher Rita Villanueva explains that “monitoring our coasts and, above all, beach erosion is crucial to formulating strategies that can make the coast more resilient, but it requires a lot of work”. That is why this initiative involves citizen collaboration in the data collection process while they enjoy a walk or a day at the beach. All they have to do is approach the control points installed on the four aforementioned Galician beaches and take a photo with their mobile phone, and then upload it to the project’s social networks or send it to the researchers. So far, they have 1582 images, of which 730 correspond to the bases of Rodas beach, 658 to Agrelo, 127 to Lanzada and 70 to Area Maior.
CostSnap turns to citizens because long-term monitoring requires data over a long period of time and is often “difficult to complete without a team of people who can repeat the studies in these areas regularly, recording large amounts of information such as the shape of a beach, the position of the coastline, the width of the sand… etc.” This is where citizens can help, emphasizes González Villanueva, “acting as scientists and collaborating by contributing their bit of area.”
To do this, they simply need to use the supports installed on the beaches to support their mobile phones. “By using these bases, the photographs are taken at a consistent location and angle, which means that once compiled, they provide a time-lapse of the coast and can be analyzed to see how it changes over time.” To facilitate the process of taking and sending the images, the project has a mobile application.
The importance of having data from the whole year
The aim is to record the cycles of erosion and recovery, and any long-term changes, “which will help us understand why some beaches are more dynamic or resilient than others”. The researcher explains that each stretch of coast behaves differently and, while one beach can grow and accumulate sediments, others lose them and erode over time. “This erosion can be the result of everyday processes such as waves reaching the coast, but it can also be caused by events such as high-energy storms that impact the coast”. Thus, if this erosion is continuous, the coast can retreat, “a fact that causes special concern especially in coastal towns or villages” and this is where the need arises for the scientific community to have a community database in which changes in beaches captured from the same position and angle of view over time are recorded, which are the basic criteria of the CostSnap project.
However, the project researchers explain that the vast majority of the photographs submitted by users, especially those of the Cíes and A Lanzada islands, correspond to the summer season. “These images help us see the recovery of the coast, but it would be interesting to also have contributions in autumn and winter, when storm events cause the greatest changes to our coast.” They point out that some of these areas, mainly Rodas beach, are difficult to access in winter, “but in other cases we hope that the initiative will continue to grow and that citizens will commit to it.”
Among the analyses already carried out, for example, explains Rita González Villanueva, who used the images received to calculate how Rodas beach was recovering after the winter storms of 2018. They detected an increase in the width of the sandbank with maximums of up to 40m. In the case of Agrelo beach, in Bueu, after the winter storms, throughout the summer of 2019 the images were analyzed with the same tide heights, being able to obtain the coastlines and calculate the width of the beach to see how it changed over time. Thus, after the winter Agrelo beach was recovering, with an average growth rate of 0.18 meters per week.
Source: DUVI
