Abstracts

Earth’s gravitational field from terrestrial mass changes and has been shown in several
studies to be sensitive to changes in groundwater. The objective of this study is to examine
the applicability of GRACE measurements of groundwater changes from 2003 to 2013 for
identification and monitoring of low water conditions. Two regions in Southern Ontario
are examined over the study period; the Cataraqui and Quinte areas in the Southeast and
the Grand River and Nottawasaga Valley areas in Southcentral Ontario. The Global Land
Data Assimilation System (GLDAS) is a land surface model which contains monthly data
for snowmelt and soil moisture. Monthly measurements of GRACE data when combined
with the corresponding GLDAS data are used to determine the change in groundwater.
The values obtained from data analyses will be compared with groundwater observations
measurements (e.g. water well data from provincial monitoring networks) to determine
the suitability of GRACE-derived measurements for the detection of low groundwater
conditions. Preliminary results investigating Southeastern Ontario at a 26,000 km 2 scale
from 2009 to 2013 showed that GRACE is sufficiently sensitive to obtain a meaningful
signal during periods of low water conditions. In 2012, for example, the study area was
observed to have a lower groundwater level in the late summer than any other time in the
study correlating to the Province’s documentation of low water conditions during that time
period. The findings of this study will be applicable to drought monitoring networks such
as the OLWRP and will be useful for conservation authorities and local governments.
This research will also aid studies looking at groundwater level changes in watersheds with
limited well monitoring networks including remote regions and developing nations.
165 - Characterising water storage change of Canada’s landmass
using GRACE satellite observations
Shusen Wang
Canada Centre for Remote Sensing, Natural Resources Canada
The GRACE satellite, a first-of-a-kind mission launched in March of 2002, has been
mapping the Earth’s gravity field with an efficient and cost-effective way at an unprecedented
accuracy. GRACE has enabled scientists for the first time to measure the total
water storage change (TWS) of the Earth’s landmass from space. In this study, the TWS
retrieved from GRACE observations for Canada’s landmass during the 11 years of 2003-
2013 is used to characterize the TWS climatology. The seasonal variations and decadal
trends of TWS during 2003-2013 over different regions in Canada are analyzed. A principle
component analysis (PCA) is used to reveal the major variation anomalies and their
drivers. Applications of the GRACE observations in water budget quantification, flood
forecasting, drought monitoring, glacier and snow cover change detection, and climate
change impacts assessment will be also discussed.
143 - Comparison of predicted and actual impacts-dewatering of
a local shallow sand aquifer-Fergus, Ontario
Dwight Smikle, David Wilson, & David Hopkins
R.J. Burnside and Associates Limited, Guelph, Ontario, Canada
182 IAH-CNC 2015 WATERLOO CONFERENCE