The Panola Mountain Research Watershed: 37 Years of Research at
a Forested Headwater Catchment in the Piedmont of the Southeastern
United States
By Brent T. Aulenbach, Jeffrey W. Riley, and Marcella A. Cruz
U.S. Geological Survey, South Atlantic Water Science Center, 1770
Corporate Drive, Suite 500, Norcross, GA 30093 btaulenb@usgs.gov
To be submitted to the Frontiers in Hydrology Meeting (San Juan, Puerto
Rico), June 19–24, 2022. Session: The Catchment Showcase: Highlighting
Research and Observatory Catchments that Span the Globe. Character
limits: 300 title; 2,000 abstract text excluding spaces, currently 144
title; 1,978 abstract text.
Session description : Catchment studies have shaped
transdisciplinary science, environmental policy, and management
decisions. We need them now more than ever for assessment of
environmental processes in a fast-changing world. This is not a session
for research findings. Rather, this poster session is an opportunity to
showcase your catchments and their features, monitoring, research agenda
and data availability. Engage with potential cooperators and data-users.
The session is also a forum for the catchment science community to
evaluate the scientific merit and societal relevance of catchment
studies. We encourage: (1) overviews of catchment studies, including
site characteristics, data, experiments, and key findings; (2)
discussion with the community to share data, synthesize findings, and
catalyze transformative ideas; and (3) the exchange of ideas to ensure
long-term funding support to continue catchment studies into the future.
Put your catchment on the map and demonstrate how long-term catchment
research is vibrant, relevant, and irreplaceable.
The Panola Mountain Research Watershed (PMRW) is a 41-hectare, forested
research catchment within the Piedmont Province of the United States
(U.S.), located about 25 km southeast of Atlanta Georgia (33˚ 37’ 54”
N, 84˚ 10’ 20” W). Annual precipitation (P) averages 1,250 mm
(<1% as snow) and annual runoff averages 358 mm, resulting in
a runoff ratio of 0.29 (based on water years 1986–2015; annual range
0.13–0.50). The PMRW is seasonally water limited which results in water
deficits and long-term actual evapotranspiration (ET) is about 75% of
potential ET. Recharge of storage occurs predominantly in
September–March when ET is lower.
The U.S. Geological Survey (USGS) initiated research at the PMRW in
1985. Early focus on the effects of acid deposition transitioned to
investigating processes affecting streamflow generation and water
quality as part of a network of five diverse U.S. watersheds in the USGS
Water, Energy and Biogeochemical Budgets Program (1991–2016). Current
research is funded by the USGS Ecosystems’ Climate Research and
Development Program and is focused on the effects of droughts and
climatic change on ET, soil moisture, groundwater recharge, and
streamflow generation. Collaboration with many Universities have
occurred throughout the study. Long-term monitoring includes P,
streamflow, groundwater, soil moisture, and meteorological parameters
and water quality sampling of P, streamwater, and soil water. Thirty
years of monthly water budgets (including actual ET and watershed
storage components) and 31 years of atmospheric deposition and
streamwater solute fluxes are published in USGS ScienceBase and include
supporting data. The PMRW has long water residence times despite its
small size, with a volume-weighted mean streamwater transit-time of
~4.7 years but can be >10 years during dry
years. The PMRW has a large dynamic (>500 mm) and total
(~1,000 mm) watershed storage with a hydrologic
persistence of 19-months, which is evident from the water budget
response to recurring hydrologic droughts. The dominant flowpath of
hillslope recharge to the riparian area and stream is through bedrock.
Storm-streamwater quality response was controlled by riparian (not
hillslope) groundwater. We welcome opportunities for collaborative
studies, cross-site comparisons, and data sharing.