Nested groundwater flow systems in Wood Buffalo National Park, Alberta-Northwest Territories, Canada

• Author / Creator

  Judit Deri-Takacs

• Water chemistry, numerical simulation and groundwater-related surface phenomena were combined into one integrated model to confirm the different scales and segments of flow systems in Wood Buffalo National Park (WBNP). Total Dissolved Solid (TDS) concentrations in surface waters and springs in WBNP range from less than 1,000 mg/L to more than 300,000 mg/L. Hydrochemical facies of the waters form four distinct groups: 1) sodium- and chloride -dominated waters, 2) “mixed”-type of waters, 3) calcium- and sulphate-dominated waters, and 4) calcium- and bicarbonate-dominated waters. The origin of waters in WBNP is meteoric water rather than formation fluids of the Alberta Basin. The geochemical character of waters resulted from three main rock-water interactions: dissolution of halite, dissolution of sulphate minerals (gypsum, anhydrite), and dissolution of carbonates. The water chemical characteristics reflect different scales and segments of flow systems in the study area.The flow regime in WBNP exhibits hierarchically nested regional, intermediate and local scale flow systems. Simulation results demonstrate that the Caribou Mountains create an isolated flow regime in the park which prevents formation fluids from basin-scale flow systems entering the WBNP region. The decreasing thickness of the basin and the topographic elevations of the Caribou Mountains induce a regional-scale flow system in the deep part of the domain that limits deep, basin-scale fluid-flow.Surface-related phenomena related to groundwater discharge include water chemical characteristics, as well as presence of wetlands, springs, saline soils, phreatophyte/halophyte vegetation, karstic features and geothermal anomalies. These phenomena indicate discharge from different scales of groundwater flow systems.Wetlands, fresh water springs and phreatophyte vegetation indicate groundwater discharge of short flow systems near the Caribou Mountains and in the Salt Plains. Wetlands accompanied by springs with elevated TDS and Ca-SO4-type water, hypogene karstification and thermal anomalies signify ascent of groundwaters from intermediate-scale flow systems in the central lowlands. Saline/brine springs, salt crusts, phreatophyte/halophyte vegetation and positive thermal anomalies indicate ascending regional groundwater flow in the Salt Plains area.The results and interpretations presented here advance the knowledge on the hydrogeological processes and interactions of groundwaters and surface waters in WBNP. This improved knowledge of hydrogeological conditions provides can be used for management decisions to protect the unique ecological values of WBNP.

• Subjects / Keywords

  • regional groundwater flow
  • groundwater
  • Wood Buffalo National Park
  • nested flow systems

• Graduation date

  Spring 2019

• Type of Item

  Thesis

• Degree

  Doctor of Philosophy

• DOI

  https://doi.org/10.7939/r3-hq5x-8t41

• License

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