Hydrogeology and hydrogeochemistry of the Chaudière River watershed aquifers, Québec, Canada
Bibliographic record
Abstract
A comprehensive hydrogeological study has been conducted in the Chaudière River watershed (6695 km2) located south of the St. Lawrence River, near Québec City. Updated maps of simplified bedrock geology and surficial sediments are presented together with the newly generated maps of the regional potentiometric surface, spatial distribution of the annual infiltration rate and spatial distribution of encountered groundwater types. Detailed analyses of the hydraulic conductivity, groundwater use, salinity sources and isotopic signatures are conducted. At the end, a conceptual model describing the hydrogeological setting is proposed for the regional groundwater flow system. In the watershed, about 150,000 inhabitants or roughly 80% of the total population depend almost entirely on groundwater as a source of potable water. Fine-grained sedimentary rocks of the Appalachian geological province form the major regional aquifer unit. The aquifer is generally unconfined to semi-confined in the Appalachian Uplands, and semi-confined to confined in the Appalachian Piedmont. Local granular aquifers are composed of coarse river valley sediments, but their extent and thickness vary throughout the watershed. The hydraulic connection between the granular units and bedrock is strongly influenced by the nature of the ubiquitous glacial sediments. The overall recharge rate to the bedrock aquifers is estimated at about 27 mm/y, or roughly 180 Mm3/y, compared to the average groundwater use of 17.4 Mm3/y. The low hydraulic conductivity, K~8×10−7 m/s, constrains groundwater flow to the top portion of the fractured strata. Groundwater flow in the Appalachian Uplands occurs at local scale and is dominated by recent recharge. Further along the flowpath in the Appalachian Piedmont, the concentrations of the major chemical constituents gradually increase along with the radiocarbon age of groundwater. Still, independent of their location along the flowpath, groundwater samples always contain a fraction of relatively young water (≤ 50 years).
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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 | 0.002 | 0.004 |
| Science and technology studies | 0.002 | 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) | 0.003 | 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".