Big Data for a Big Country: The First Generation of Canadian Wetland Inventory Map at a Spatial Resolution of 10-m Using Sentinel-1 and Sentinel-2 Data on the Google Earth Engine Cloud Computing Platform

摘要

Detailed information on the spatial distribution of wetlands is crucial for sustainable managementand resource assessment. Furthermore, regularly updated wetland inventories are of particularimportance given that wetlands comprise a dynamic, rather than permanent, landcondition. Accordingly, satellite-derived wetland maps are greatly beneficial, as they capture asynoptic and multi-temporal view of landscapes. Leveraging state-of-the-art remote sensingdata and tools, this study produces a high-resolution 10-m wetland inventory map of Canada,covering an approximate area of one billion hectares, using multi-year, multi-source (Sentinel-1and Sentinel-2) Earth Observation (EO) data on the Google Earth Engine™ cloud computingplatform. The whole country is mapped using a large volume of reference samples using anobject-based random forest classification scheme with an overall accuracy approaching 80%and individual accuracies varying from 74% to 84% in different provinces. This nationwide wetlandinventory map illustrates that 19% of Canada’s land area is covered by wetlands, most ofwhich are peatlands dominate in the northern ecozones. Importantly, the resulting everdemandingwetland inventory map of Canada provides unprecedented details on the extent,status, and spatial distribution of wetlands and thus, is useful for many stakeholders, includingfederal and provincial governments, municipalities, NGOs, and environmental consultants.