The document summarizes a study that deployed various hydrological tools along the East Fork of the Jemez River in New Mexico to understand linked physical and chemical processes. Key findings include: 1) The Jemez River is overall gaining based on positive head gradients measured along the riverbed and higher water table depths measured farther from the river. 2) Analysis of chloride concentrations and thermal data from instruments in the riverbed suggest mixing is occurring between groundwater and the hyporheic zone of the riverbed and banks. 3) Spatial temperature variations recorded over two days indicate surface water is entering the hyporheic zone in some locations with lower magnitude variations under vegetation.

1. A diverese toolbox of hydrological tools were deployed along the East Fork of
the Jemez River, within the Valles Caldera National Preserve, NM in order to
understand potentially linked physical and chemical processes across a riv-
ResultsIntroduction
Dylan Hart1
, Edna Rodriguez1
, Elyse Nichols1
, Bayani Cardenas1
, Stephen Ferencz1
, George Perkins2
, Robert Parmenter3
, and
The 2016 University of Texas Hydrogeology Field Camp1
1
University of Texas at Austin, Dept. of Geological Sciences 2
Los Alamos National Laboratory 3
National Park Service
Water Table Map and Riverbed Head Gradient
Thermal Data
Objectives
• Is the Jemez River gaining or losing?
• How can the local hyporheic zone hydrology be characterized by thermal
the groundwater-surface water interaction?
Study Site and Location
Field Photos
Methods
• Collected water table depths from installed piezometers using water tape
• Collected ground and surface water samples for lab analyis
• Installed thermistors in the Jemez River
• The Jemez River is overall gaining, as seen in
the Water Table Map
summer season, we observed a drop in the
water table of max magnitude ~10 cm at
piezometers farthest away from the river.
• Processes such as mixing of groundwater and
the hyporheic zone of the river’s bed and banks
could be the cause of the observed trends in the
chloride data.
• Spatial temperature variations recorded over
the course of two days suggest
face water into the hyporheic zone at the
• Thermistors #3 and #4 (under vegetation) expe-
much lower magnitude
Future Work
Expand study to consider seasonal variability of
groundwater exchange, especially during times of
East Fork Jemez River.
Red square is a research enclo-
sure within Valles Caldera
Team deployed 7 thermistor setups to measure the lateral change in vertical tempera-
and #4 positioned under the vegetation.
Each thermistor were set up with four measuring points arranged vertically, spaced 25
cm, 15 cm, 10 cm, and 5 cm below the riverbed ground surface.
Flow Direction
Chemical Analysis
General increase in chloride concentration should be observed along a sub
-
-tions were observed decreasing downstream
Riverbed
0.25 m
10 AM
5 PM
10 PM
5 AM
Riverbed
0.25 m
Riverbed
0.25 m
Riverbed
0.25 m
#5 #4 #3 #2 #1
• Temporary piezometers were installed along the portion
of the Jemez River transiting through the study area to eval-
-
uate head gradients along the stream.
• All measured riverbed gradients were positive within the
enclosure, and values ranged from 1-6cm.
the water table of maximum magnitude ~10cm at piezometers farthest away
from the river
#5 #4 #3 #2 #1
A
A
B
BA
Transverse Groundwater Temperature Profile
10 AM
5 PM
10 PM
5 AM
Flow Direction
Riverbed
Riverbed
Riverbed
Riverbed
Data collected during UT’s hydrology field camp.