Critical Zone Measurements: Development of Novel Experimental
Deployments to Further Our Understanding of Hydrological Processes
Abstract
Since 2013 Susquehanna Shale Hills Critical Zone Observatory (SSHCZO)
has been monitoring using a Ground Hydrological Observation System
(GroundHOG) design consisting of various sensor types in the Shavers
Creek watershed in central Pennsylvania. The GroundHOG design was
established to study interactions between hydrological systems (surface
and groundwater), soils, and ecosystems along catenas. We currently have
three GroundHOG sites with differing land uses and geology: one located
in a pristine shale watershed, another in a pristine sandstone
watershed, and the third in an agricultural setting with mixed
lithology. Each catena has three pits set up to compare hill slope
position and one additional pit to compare north versus south aspect.
Each pit is equipped with both automated and manual sensors that measure
soil moisture and soil gas at varying depths. The GroundHOG deployment
is accompanied by precipitation gauges, surface water monitoring gauges,
and groundwater monitoring wells at all sites. In 2019 we built on the
shale site to include weekly electrical resistivity measurements and
seismometry near the GroundHOG. Specifically, we designed and installed
an innovative chronoamperometric system that can respond to real-time
redox reactions that change in response to changes in soil moisture,
temperature, and saturation. These experimental sensors are co-located
with the GroundHOG sites where soil gas measurements take place and can
be coupled to understand the connection of hydrological processes to
microbial communities. This presentation will emphasize the design of
the GroundHOG and how the new measurements are made and compared in the
shale GroundHOG site.