Mudbanks on the Guianas coast. Using satellite images to study the spatial distribution of mudbank

mudbanks that are important for the dynamics of the coast. In areas were mudbanks lie in front of the coast the area is protected from wave action and accumulation can take place. In the area between the banks the coast is susceptible for erosion. The mudbanks are constantly migrating along the coast, causing the areas of erosion or accumulation to move as well. The coastal area, up to 77 km land inwards, is home to ninety five percent of the inhabitants of these countries that are influenced by changes to the coast. The mudbanks and the coast have been extensively studied, but there still remain many unknowns. For example, how will global climate change and subsequent sea-level rise in the area, influence the mudbank dynamics? And what are the other main factors that play a role in the distribution and form of the mudbanks? In this study 34 years of satellite images, from the Landsat 4, 5, 7 and 8 satellites from 1984 till 2017, were analysed by using Google Earth Engine and ArcGIS Pro to identify patterns in the mudbank dynamics. A CART classification was used to classify the images using the four classes land, water, intertidal mudbank and subtidal mudbank. This classification method has an accuracy of approximately 83-87 %. The classification images were exported to ArcGIS Pro to enhance and analyse them. The classifications were placed as outlines over the original Landsat images to show how the classification data correlates with the real situation. The images were compared for each year, looking at the locations, size, form and amount of mudbanks. Different patterns in the changes of the mudbanks were identified. The bank size and form differ from year to year, with some banks eroding while others are growing due to the redistribution of the sediment. Some changes can be linked to high wave or storm events, such as the decrease in size in 2005, which happened after a high wave event had occurred. Phases of erosion and accretion of the banks are also linked to the direction and strength of the trade winds. Beside natural fluctuations, human activity plays an important role in the bank dynamics as well. The removing of mangrove forests for economic profits can reduce the bank strength which will result in more erosion.