Wetland Change Analysis in Alberta, Canada Using Four Decades of Landsat Imagery

Abstract

In this study, wetland trends in Alberta were investigated in the past four decades using Landsat satellite imagery to produce updated information about wetland changes and to prevent further degradation of these valuable natural resources. All the processing steps and analyses were conducted in Google earth engine (GEE) to produce 16 wetland maps from 1984 to 2020. A comprehensive change analysis showed 1) approximately 18% of the province was subjected to change; 2) in terms of wetland classes, there was a decreasing trend for the Shallow Water and Swamp classes and an increasing trend for the Fen and Marsh classes; 3) in terms of nonwetland classes, there was a considerable decreasing trend for the Forest class and increasing trend for the Grassland/Shrubland class; 4) wetland loss was approximately 22 000 km2, which was mainly due to the conversion of wetlands to Forest and Grassland/Shrubland; 5) wetland gain was approximately 24 000 km2, which was mainly due to the conversion from the Forest class to wetlands, especially the Swamp and Fen classes; 6) the highest class transition was from Cropland to Grassland/Shrubland and vice versa (29 000 km2), from Forest to different wetland classes (18 000 km2), and from Fen to Forest (6000 km2). In summary, the results of this study provided the first comprehensive information on wetland trends in Alberta over the past 37 years and will assist policymakers to adjust the required/established policies to mitigate the potential wetland changes due to anthropogenic activities and climate-related events.