Leveraging Earth Observations and In Situ Data in Support of Groundwater
Sustainability
Abstract
Water managers face the daunting task of managing freshwater resources
in the face of industrialization and population growth. As surface water
resources become fully allocated, increased groundwater use can fill the
void, particularly during periods of drought. Improper groundwater
management can result in reduced water quality, land subsidence,
increased pumping costs, and in some cases, the complete exhaustion of
an aquifer and the loss of groundwater as a buffer during times of
drought. Assessing the long-term impact of various groundwater
management decisions can be difficult and costly, and therefore many
decisions are made without sufficient analysis. Advancements in the
acquisition and dissemination of Earth observations, coupled with
advances in cloud computing, web apps, online mapping, and visualization
provide a unique opportunity to deliver tools and actionable information
to groundwater managers to assist them in addressing global and regional
challenges and opportunities. We have developed a web-based tool that
ingests in situ groundwater level measurements for specific aquifers and
generates time series plots, maps, and raster animations showing
groundwater depletion over time and short-term projections into the
future. This process involves both temporal and spatial interpolation
algorithms. In some aquifers, the observation wells are sparse and/or
the historical observations have large gaps, leading to greater
uncertainty in the interpolation and the resulting groundwater depletion
estimates. To address this, we utilize Earth observations (GRACE, SMAP,
etc.) and a co-kriging algorithm to enhance the interpolation process.
The utility of the Earth observations in improving the estimates is
evaluated using a jackknifing process. We present case studies for
application of the system in the states of Utah and Texas.