| Titre | Hydrogeological tools for characterizing groundwater discharges to surface water: advantages, disadvantages, and the importance of proper timing |
| Télécharger | Téléchargement (publication entière) |
| |
| Licence | Veuillez noter que la Licence du gouvernement
ouvert - Canada remplace toutes les licences antérieures. |
| Auteur | Brewster, C, Jr |
| Source | Regional-scale groundwater geoscience in southern Ontario: an Ontario Geological Survey, Geological Survey of Canada, and Conservation Ontario open house; par Russell, H A J ; Ford, D; Priebe, E H; Commission géologique du Canada, Dossier public 8212,
2017 p. 8, https://doi.org/10.4095/299764  Accès
ouvert |
| Année | 2017 |
| Éditeur | Ressources naturelles Canada |
| Réunion | Ontario Geological Survey and Geological Survey of Canada groundwater geoscience open house; Guelph; CA; mars 1-2, 2017 |
| Document | dossier public |
| Lang. | anglais |
| DOI | https://doi.org/10.4095/299764 |
| Media | en ligne; numérique |
| Référence reliée | Cette publication est contenue dans Regional-scale groundwater geoscience in southern Ontario: an Ontario Geological Survey, Geological Survey of Canada, and Conservation Ontario open house |
| Formats | pdf |
| Sujets | eau souterraine; aquifères; ressources en eau souterraine; gestion des ressources; résurgence des eaux souterraines; eaux de surface; régimes des eaux souterraines; écoulement de la nappe d'eau
souterraine; qualité de l'eau; écosystèmes; terres humides; inondations; milieu hydrologique; propriétés hydrologiques; établissement de modèles; températures des eaux souterraines; niveaux d'eau; niveaux piézométriques; hydrogéologie; géologie de
l'environnement |
| Programme | Géoscience des eaux souterraines , Aquifer Assessment & support to mapping |
| Diffusé | 2017 02 22 |
| Résumé | (disponible en anglais seulement)
Many of the water management responsibilities of Conservation Authorities require an understanding of groundwater/surface-water (GW/SW) interactions. GW/SW
interactions play a major role in the physical, chemical, and biological integrity of surface water and groundwater systems and are relevant to: source water protection; protection of groundwater dependent ecosystems; protection of wetlands,
management of fisheries; assessment of the effects of land use changes on watersheds; and the prediction and management of floods. The type and amount of hydrological data needed to answer specific management questions will vary greatly. If financial
or personnel resources are limited, it is a challenge to collect data at a sufficient scale and frequency to ensure a full understanding of the system.
The complexity of GW/SW systems means it can be difficult to collect enough data to put it all
into proper hydrological context and develop reliable conceptual models of the GW/SW interactions. Therefore, there is a need for inexpensive and cost effective methods and tools to efficiently characterize groundwater discharges and GW/SW
interactions on both large and small scales. To address this problem, a multi-scale, multi-technique characterization approach is proposed, where large-scale large-area reconnaissance methods are used to quickly assess large areas and identify the
largest groundwater discharges. This work is then followed by progressively smaller-scale characterization techniques (with successively higher sensitivity) to make point measurements of groundwater discharge and GW/SW interactions and quantify
fluxes.
The reconnaissance methods consist primarily of temperature-as-a-tracer methods (i.e., aerial thermal infrared surveys, drag probe surveys, and streambed/lakebed temperature mapping) that are very useful and relatively inexpensive methods
for delineating groundwater discharges. The reconnaissance results are used to pick locations for more conventional and/or point measurement techniques (i.e., differential streamflow gauging, monitoring water levels, mini-piezometers, seepage meters,
and lakebed/streambed temperature monitoring and modeling) to characterize the groundwater flow directions (discharge versus recharge) and quantify fluxes.
An overview of the overall approach and a brief description of the advantages and
disadvantages of each technique will be provided. This approach can obtain good spatial characterization of GW/SW interactions; however, timing of the data collection is critical. All data collected should be put into the context of (and help define)
how the hydrological system changes over time, because groundwater discharge and GW/SW interactions are not constant over time. For temperature-as-a-tracer methods, timing of data collection is of paramount importance. Temperature based GW/SW
interactions methods are deceptively simple and can provide excellent information; however, collecting data when there is poor or no contrast between surface and groundwater temperatures should be avoided, because it can result in useless or
misleading results. If properly applied, the multi-scale, multi-method characterization approach can be a cost effective way of comprehensively characterizing groundwater discharges and GW/SW interactions and help improve decision making with respect
to managing natural resources. |
| Sommaire | (Résumé en langage clair et simple, non publié)
Procès-verbaux pour la géoscience des eaux souterraines à échelle régionale Organisée par la Commission géologique de l'Ontario, la Commission
géologique du Canada et les géoscientifiques de Conservation Ontario. La journée portes ouvertes est prévue pour 2017-03-01 et 02. L'objectif est l'engagement du public et la diffusion de la géoscience dans le sud de l'Ontario au cours de la dernière
année. |
| GEOSCAN ID | 299764 |
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