Athabasca Region Athabasca River Cumulative effects assessment (Environmental assessment) Environmental impact analysis Environmental problems Hydrology acidification air quality anthropogenetic stressors applied modeling system applied modelling atmospheric deposition climate change cumulative effects assessment environmental analysis environmental impact assessment environmental model environmental modelling environmental modelling framework environmental planning ground water interaction groundwater hydrodynamics hydrology integrated model integrated modelling land use/land cover load allocation natural stressors surface water