The hydrologic behaviour of waste rock piles in the Canadian Arctic : snowmelt infiltration and the onset of long term freezing in test piles
Bibliographic record
Abstract
This thesis examines the hydrology of three experimental waste rock piles located in the Canadian Arctic at Diavik Diamond Mine (DDMI). Seven years of hydrology data is presented, including measurements of moisture contents, outflow volumes and soil tensions, along with an estimate of annual rainfall infiltration. The hydrology of each pile is influenced by freezing and thawing, and pore water flow is restricted to the time periods when the pile is thawed. The base of each pile contains drain pipes used to collect pore water from the piles, and these pipes are lined with internal heat traces. This research shows that the heat traces significantly influence the thermal behaviour and hydrology of the waste rock. A flooding event in the winter of 2012 interrupted power to the heat trace in two of the waste rock piles, and led to altered outflow volumes and patterns in 2013. A heat trace in the base of the third pile was intentionally turned off in 2011, and led to a significant decrease in the volume of outflow collected from the pile in 2012 and 2013. A bromide tracer was applied to the crest of one of the piles in 2007, and the recovery of the tracer is analysed until 2013. The results of this analysis are used to quantify the average residence time and flow velocity of pore water within the pile. The concentration of stable isotopes is analysed in outflow from the same pile, and is used to estimate the contribution of snowmelt to the total recharge received by the pile. The infiltration of snowmelt into another waste rock pile is estimated using the results of four snow surveys, a snowmelt ablation model, and an infiltration model suitable for use on frozen porous media. The research contained in this thesis provides information that will be incorporated into the final closure plan for DDMI, and will be used to help prevent the formation and release of low quality effluent from the full scale waste rock pile located at the mine site.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.003 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".