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TitleGroundwater storage change detection using ground-based temporal micro-gravity changes in Waterloo Moraine
AuthorEl-Diasty, M; Huang, J; Liard, J; Silliker, J; Jobin, D; Wang, S; Wang, J
SourceIAH 2012 Congress: International Association of Hydrologists, abstracts volume; 2012 p. 1
Alt SeriesEarth Sciences Sector, Contribution Series 20110421
PublisherInternational Association of Hydrogeologists
MeetingIAH 2012 Congress: International Association of Hydrologists; Niagara Falls, ON; CA; September 16-21, 2012
File formatdocx (Microsoft® Word®); pptx (Microsoft® PowerPoint®)
Subjectshydrogeology; geophysics; Science and Technology; Nature and Environment
ProgramAquifer Assessment & support to mapping, Groundwater Geoscience
Released2012 09 01
AbstractFor local scale water basins, time-varying ground-based micro-gravity signals can be employed to detect groundwater storage changes. In this paper, we show recent developments in groundwater storage change detection using ground-based (absolute and relative gravimeters) technology for the Waterloo Moraine case study. Four epochs of gravity survey were conducted in the Waterloo Moraine in Mays and Augusts of 2010 and 2011, respectively. The 85 field stations were measured in 2010 and a subset of them (47 stations) were re-occupied in 2011. A reference station was established in the University of Waterloo using the absolute gravimeter (FG5). Two relative gravity meters (CG5) and two geodetic GPS receivers were deployed for the field surveys. Soil moisture data were also collected in May and August 2010.
In this paper we mainly focus on data processing, analysis and interpretation of the gravity changes using rigorous parametric least squares method integrated with hydrological models and geological studies. In the analysis, the gravity differences between Mays and Augusts for 2010 and 2011 epochs are inverted to provide the estimated total water storage changes. Then, the simulated soil water change of unsaturated layers from two different Land Surface Models (LSM), namely Ecological Assimilation of Land and Climate Observations (EALCO) of NRCan and Global Land Data Assimilation System (GLDAS) of NASA (four models: CLM, MOSAIC, NOAH and VIC), are subtracted from the estimated total water storage changes to provide the estimated groundwater storage change. To validate the results of this developed method, the ratios (specific yields) between the estimated groundwater storage changes and measured water table changes are estimated at a few inferred monitoring wells around the survey area. Preliminary results show that the estimates of specific yields between Mays and Augusts of 2010 and 2011 are consistent at a significant confidence level and are also within the range of the specific yield from hydrological and geological studies. Therefore, the ground-based (absolute and relative gravimeters) technology has demonstrated the great potential in groundwater storage change detection for local scale water basins.