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Our study encompasses the Oil Sands Area (OSA) within northern Alberta, Canada, which has experienced substantial environmental changes over the last decades, in association with natural and anthropogenic disturbances. Using composites of Landsat imagery for 5-year intervals between 2000 and 2020, we performed two parallel geospatial analyses to assess environmental changes, examining landscape metrics and spectral indices. Landscape metrics were calculated from land use/land cover maps derived from a Random Forest supervised classification. Spectral indices included Normalized Difference Vegetation Index (NDVI) and Normalised Difference Built-up Index (NDBI), among others. Both hierarchical zonal analysis of spectral indices and zonal landscape metrics were calculated based upon two different aggregations of nested drainage basin features from hydrologic unit code (HUC - Watersheds of Alberta). Spatial contiguity of changes was evaluated by hotspot analysis. HUCs determined to experience significant changes at coarse aggregation level were examined at finer level. The combination of landscape metrics and zonal analysis provided evidence of substantial, yet localized, areas of changing trends. Mixed forest experienced the most significant changes; urban/barren areas initially increased and later decreased, indicating change both in agricultural and humanmade areas. [ABSTRACT FROM AUTHOR]