Hydrogeochemistry Studies in the Oil Sands Region to Investigate the Role of Terrain Connectivity in Nitrogen Critical Loads

Hydrology and geochemistry studies were conducted in the Athabasca Oil Sands region to better understand water nitrogen cycles at two selected sites order assess potential for transport between adjacent terrain units. A bog—poor fen—upland system was instrumented near Mariana Lakes (ML) (55.899° N, 112.090° W) a rich JPH (57.122° 111.444° W), 100 km south 45 north of Fort McMurray, Alberta respectively. LiDAR surveys initially delineate watershed boundaries topography select range specific locations installation table wells groundwater piezometers. Field work, which included physical measurements as well sampling geochemical isotopic characterization, carried out mainly during thaw seasons 2011 2015. From analysis runoff response species abundances we estimate that exchange wetlands units ranged 2.2 −3.1 kg/ha/year fens, 0.6 −1.1 poor −2.5 bogs, predominantly via surface pathways form dissolved nitrate. significant storage ammonium (and also organic nitrogen) found within pore bog-fen complex Lakes, attribute decomposition, although it is likely immobile under current hydrologic conditions, suggested by tritium distributions. In comparison with experimental loads 5 25 kg/ha/year, expected have only minor or negligible influence, therefore secondary importance defining critical across regional landscape. Climate change development impacts may lead mobilization storages, more research required quantify effects on local ecosystems.