2 research outputs found
Intégration de données électromagnétiques transitoires au sol et héliportées en Montérégie-Est par déformation graduelle
RĂSUMĂ : Dans ce travail, j'ai dĂ©veloppĂ© un algorithme stochastique d'inversion conjointe de donnĂ©es Ă©lectromagnĂ©tiques transitoires au sol NanoTEM et hĂ©liportĂ©es VTEM-plus. Ces donnĂ©es avaient Ă©tĂ© acquises lors de la premiĂšre phase du Programme d'Acquisition de Connaissance sur les Eaux Souterraines (PACES) dans la rĂ©gion de MontĂ©rĂ©gie-Est, QuĂ©bec, (Canada). Les objectifs visĂ©s Ă©taient de : (1) Ă©valuer pour les deux systĂšmes, dans le contexte gĂ©ologique de la MontĂ©rĂ©gie-Est, la capacitĂ© de dĂ©tection de proche surface et la profondeur d'exploration dans le cadre d'une Ă©tude hydrogĂ©ologique rĂ©gionale ; (2) traiter et inverser par mĂ©thode conventionnelle (moindres-carrĂ©s amortis) les courbes dbz/dtobs mesurĂ©es, et interprĂ©ter les rĂ©sultats afin d'expliquer la diffĂ©rence observĂ©e dans les modĂšles Ă©lectriques obtenus par les inversions conventionnelles (HLCI) du VTEM-plus mesurĂ© prĂ©alablement par la compagnie Geotech.Ltd et LCI du NanoTEM mesurĂ© par l'INRS; (3) dĂ©velopper une mĂ©thodologie algorithmique novatrice pour gĂ©nĂ©rer des modĂšles stochastiques gĂ©oĂ©lectriques 2D de haute rĂ©solution qui ajustent conjointement les courbes dbz/dtobs NanoTEM et VTEM-plus.----------ABSTRACT : I developed a stochastic algorithm for joint inversion of ground-based NanoTEM and heliborne VTEM-plus Transient Electromagnetic (TEM) soundings. These data were acquired during the first phase of the regional groundwater characterization project (PACES) in MontĂ©rĂ©gie-Est, Quebec, (Canada). The objectives of this work were: (1) to estimate for both systems, in the geologic context of MontĂ©rĂ©gie-Est, the capacity of near surface detection and the depth of exploration within the framework of a regional hydrogeological study; (2) to process and invert by conventional method (damped least-squares) the dbz/dtobs curves, and interpret the results to explain the difference observed in the electric models obtained by the conventional inversions (HLCI) of the VTEM-plus and (LCI) of NanoTEM soundings measured respectively by the Geotech. Ltd company and the INRS; (3) to develop an innovative algorithm for generating a stochastic high-resolution 2D geoelectric model which adjust jointly NanoTEM and VTEM-plus dbz/dtobs curves
A framework for parameter estimation using sharp-interface seawater intrusion models
Funding : This work was supported by Quebecâs MinistĂšre de l'Environnement et de la Lutte contre les changements climatiques (MELCC) [project « Acquisition de connaissances sur les eaux souterraines dans la rĂ©gion des Ăles-de-la-Madeleine » (Groundwater characterization project in the Magdalen Islands region)]; and the Fonds quĂ©bĂ©cois de la recherche sur la nature et les technologies (FRQNT) [International internship program accessed through CentrEau, the Quebec Water Research Center]. The authors would like to thank the Municipality of Les Ăles-de-la-Madeleine for providing pumping datasets and information on current and historical groundwater management. They would also like to thank the team at UniversitĂ© Laval working on the Magdalen Islands project, for their help acquiring datasets and for field logistics, John Molson, for proofreading, and finally the two anonymous reviewers for their valuable comments. The authors would also like to thank Vincent Post for discussions on deep open boreholes, and Francesca Lotti and John Doherty for discussions on seawater intrusion modeling and data assimilation. J-C Comte and O Banton acknowledge the financial support from the Fonds d'Action QuĂ©bĂ©cois pour le DĂ©veloppement Durable for the ERT data collection, undertaken as part of the Madelin'Eau consortium (Ageos-Enviro'Puits-Hydriad), and further thank the Municipality of Les Ăles-de-la-Madeleine for fieldwork logistical and technical support.Peer reviewedproo