Multi-year hydrologic response of experimental waste-rock piles in a cold climate : active-zone development, net infiltration, and fluid flow
department or school: Science, Faculty of
department or school: Earth, Ocean and Atmospheric Sciences, Department of
data provider: DSpace
degree campus: UBCV
creator: Fretz, Nathan Mackenzie
issued: 2013-02-14T19:02:22Z
issued: 2013
related degree: Master of Science - MSc
degree grantor: University of British Columbia
description: A large-scale field study was constructed at the Diavik Diamond Mines, NT, Canada, to examine the hydrologic, geochemical, microbiologic, gas-transport, and heat-transport mechanisms that influence drainage water quality from waste-rock. This thesis focuses on the hydrology component of the project, with the aim of better understanding fluid flow through mine waste-rock at multiple scales in cold climates. The hydrologic response of two large-scale, experimental waste-rock piles (test piles) and a series of smaller-scale lysimeters (active-zone lysimeters) were monitored. Both the test piles and the active-zone lysimeters were constructed on top of water collection systems in order to monitor outflows, and were instrumented with tensiometers, moisture content sensors, and thermistors. Active-zone development, net infiltration, matrix wet-up, wetting front movement, and outflow at the test piles and active-zone lysimeters are examined. Above-freezing air temperatures result in an active-zone developing inwards into the test piles during the summer months, allowing net infiltration at the thawed surface and fluid flow through thawed regions to occur. Over a five year period the average percent net infiltration into the active-zone lysimeters and crowns of the test piles was estimated to be 43%, 57%, 15%, 41%, and 58% of natural rainfall in 2007, 2008, 2009, 2010, and 2011, respectively. An indirect evapotranspiration computation suggests that net infiltration from rainfall events <5 mm/d is restricted to periods early (May) and late (September to mid-October) in the rain-season, while net infiltration in June, July, and August is restricted to rainfall events >5 mm/d. TDR sensors are used to monitor initial wet-up of the matrix fraction and wetting front velocities. Approximate spatial uniformity of wetting front velocities for all but the most intense rainfall events, and positive correlation between outflow rate and solute/dissolved metal concentration from effluent…
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/43923
note: MULTI-YEAR HYDROLOGIC RESPONSE OF EXPERIMENTAL WASTE-ROCK PILES IN A COLD CLIMATE: ACTIVE-ZONE DEVELOPMENT, NET INFILTRATION, AND FLUID FLOW by Nathan Mackenzie Fretz B.Sc., The University of British Columbia, 2010 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in THE FACULTY OF GRADUATE STUDIES (Geological Sciences) THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver) February 2013 © Nathan Mackenzie Fretz, 2013 ii Abstract A large-scale field study was constructed at the Diavik Diamond Mines, NT, Canada, to examine the hydrologic, geochemical, microbiologic, gas-transport, and heat-transport mechanisms that influence drainage water quality from waste-rock. This thesis focuses on the hydrology component of the project, with the aim of better understanding fluid flow through mine waste-rock at multiple scales in cold climates. The hydrologic response of two large- scale, experimental waste-rock piles (test piles) and a series of smaller-scale lysimeters (active-zone lysimeters) were monitored. Both the test piles and the active-zone lysimeters were constructed on top of water collection systems in order to monitor outflows, and were instrumented with tensiometers, moisture content sensors, and thermistors. Active-zone development, net infiltration, matrix wet-up, wetting front movement, and outflow at the test piles and active-zone lysimeters are examined. Above-freezing air temperatures result in an active-zone developing inwards into the test piles during the summer months, allowing net infiltration at the thawed surface and fluid flow through thawed regions to occur. Over a five year period the average percent net infiltration into the active-zone lysimeters and crowns of the test piles was estimated to be 43%, 57%, 15%, 41%, and 58% of natural rainfall in 2007, 2008, 2009, 2010, and 2011, respectively. An indirect evapotranspiration computation suggests that net infiltration from rainfall events <5 mm/d is restricted …
has type: Thesis/Dissertation
date issued: 2013-05
is shown at: 10.14288/1.0073576
language: eng
degree discipline: Geological Sciences
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
type: Text
identifier URI: http://hdl.handle.net/2429/43923