Hydrogeological Considerations for Landscape Reconstruction and Wetland Reclamation in the Sub-humid Climate of Northeastern Alberta, Canada
Notice bibliographique
Résumé
Oil sands mining companies must reclaim tailings deposits to equivalent land capability in Alberta’s boreal forest. Post-mining landscapes should be reconstructed to promote the development of hydrologic systems that can sustain reclaimed ecosystems in a sub-humid climate, while limiting migration of salts from underlying waste materials. However, landform design requirements that foster the development of appropriate near-surface hydrologic flow systems are poorly understood. Syncrude Canada Ltd. constructed Sandhill Watershed (SHW), a 52 ha coarse-textured upland/lowland complex overlying a deep tailings deposit, to explore the influence of landform characteristics, reclamation cover choices and vegetation densities on reclamation performance. This study examines the hydrogeologic characteristics of SHW and explores the resulting groundwater flow system in the years following its construction. Field measurements collected from May to October (2015 to 2017), from 230 shallow piezometers, including groundwater measurements (water level, temperature, and electrical conductivity), water samples and soil saturation maps were used to characterize the hydrogeology. A subset of data, including stable water isotopes and elemental chemistry, were collected during 2017 to resolve the mechanisms leading to observed solute distributions. Field observations were used to calibrate a three-dimensional steady-state numerical groundwater flow model to evaluate present and possible future hydrologic systems. A shallow groundwater system dominated by lateral flow developed within SHW. The flow system is strongly influenced by hydraulic conductivity and appears to have negligible inputs from deeper groundwater. Most recharge originates from a laterally extensive upland feature coinciding with the adjacent groundwater divide, beyond the southern extent of the study area. Shallow water tables near, and standing water in, the lowlands are most sensitive to precipitation. Overall, solute concentrations increase with depth in the watershed; however, areas with shallow water tables and shallow slopes are prone to developing elevated solute concentrations following precipitation events. Analyses indicate water table configurations responded dynamically to variable recharge rates associated with the depth to water table, and reclamation prescriptions for soil and vegetation. These results indicate fresh shallow groundwater systems can develop for wetland reclamation in post-mining reconstructed landscapes. By appropriately sculpting coarse-textured construction materials during landform design, a freshwater lens developed at the water table beneath hummocks where groundwater is approximately 2 m below ground surface; here, the vertical geochemical gradient transitions from mixed-fresh groundwater to Na+ Cl-/SO4 2- enriched groundwater approximately 1.8 m below water level. Sloped areas with shallower water tables that fluctuate within the rooting zone tend to have elevated solute concentrations near the water table, especially following precipitation influxes, due to lateral groundwater seepage, groundwater ridging and evapoconcentration. These results provide guidance for designing future coarse-textured landforms and developing hydrologic systems for boreal forest reclamation. In particular, designers should reconstruct watersheds that promote groundwater recharge in upland areas by building lower and more laterally expansive hummocks than those in SHW to support water tables approximately 2 m BGS. Furthermore, the interface between the uplands and lowlands should be abrupt, to limit the extent of seepage faces. With these slight landform modifications, recharge and solutes can be better managed to allow the shallow groundwater system to remain fresh, while sustainably sourcing water to down gradient environments.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,001 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,001 | 0,002 |
| Études des sciences et des technologies | 0,002 | 0,000 |
| Communication savante | 0,001 | 0,000 |
| Science ouverte | 0,001 | 0,001 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,002 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».