A changing North: The implications of high-volume groundwater extraction and reduced water availability on sub-arctic peatland hydrology, connectivity, and geochemistry

• Main Author: Balliston, Nicole
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: University of Waterloo 2022
• Subjects: Hudson Bay Lowland; hydrology; dewatering; peatlands; watershed; mine impacts; climate change; geochemistry; hydrological connectivity; James Bay Lowland; sub-arctic; Arctic; Hudson Bay; Hudson; Attawapiskat; Climate change; James Bay
• Online Access: http://hdl.handle.net/10012/18424

Patterned bog and fen peatlands of the Hudson Bay Lowlands (HBL) currently make up 90% of land cover in this region and form one of the largest continuous peatland complexes in the world. A globally significant storage of carbon, these peatlands are also unique ecosystems and perform valuable water regulation mechanisms in HBL watersheds. At present, the HBL region faces the increasing dual threats of resource extraction operations and increasing temperatures due to climate change, both of which may reduce water availability. In spite of their global significance, there is a dearth of information on the temporal and spatial patterns of hydrological connectivity across HBL peatland complexes, as well as the relative importance and variability of meteorological parameters. Further, studies attempting to characterize the effects of reduced water availability on hydrological structure and function in HBL peatland complexes are extremely limited. Such information is required to better understand the trajectory of these systems under future disturbance scenarios. To this end, hydrological (i.e., streamflow and groundwater levels), meteorological (i.e., precipitation, snow depth, evapotranspiration, and temperature) and hydrogeological/geochemical (i.e., porewater samples, peat depth, surface elevation, and hydrophysical properties) data were collected from both disturbed and undisturbed peatland complexes in the HBL between 2007 and 2018. Disturbed peatlands were located within the de-watering radius of the De Beers Victor Diamond Mine, located 90 km west of Attawapiskat. The undisturbed peatlands studied here were mainly within a bog-fen-tributary complex ~30 km south of the impacted transect, monitored by the Ministry of Environment, Conservation and Parks. Within the unimpacted peatland complex hydrological connectivity (the ease of water movement across the landscape) was generally highest in the spring, due to freshet, and fall, due to lower evapotranspiration losses. However, water transfer between peatland ...