Coastal Wetland Response to Climate Change and Sea Level Rise

Wetlands play a crucial role in climate change mitigation due to their abilities to sequester large amounts of organic carbon. Wetlands in Canada compose roughly 1.29 million square kilometers or 13% of the country's total land mass. Canada’s wetlands are not immune to the effects of climate change, and increasing sea level rise has continued to bring strain to delicate coastal wetlands in particular. Studies into the long-term changes in these wetlands are variable, as best case scenario results estimate the sequestration of up to 1.5 Pg of organic carbon by 2100 through landward migration, though worst case scenario findings indicate that coastal squeeze could result in the loss of 3.4 Pg of sequestered carbon by 2100. This project aims to understand if the use of satellite imagery and remote sensing techniques can accurately assess and classify regions deemed as coastal wetlands. Multiple supervised classification methods were conducted on a 2024 Landsat 8 false colour composite image of a large coastal marsh in southern Nova Scotia and compared to the most up to date map from the Canadian Wetland Inventory. The most accurate method was returned, and was performed on the same area for an image in 2014 and 2005 respectively. The three classified images were then compared and overlaid onto one another to assess how the region has changed in the 20 year period. It is expected that some areas of the wetland will migrate inwards towards surrounding forested areas, as well as take over small forested islands within the marsh. Additional research into these regions conducted at areas of differing rates of sea level rise, as well as at wetlands bordering different land use types may help bring more understanding to how these ecosystems change over time according to their unique environments.