Southern
Research Station

Education

Ph.D. in Major in Forest Hydrology, Minor in Soil Science, 2005

North Carolina State University

B.S. in Mechanical Engineering, 1996

North Carolina State University

Professional Experience

Research Hydrologist, USDA Forest Service, Southern Research Station, Center for Forest Watershed Research, Coweeta Hydrologic Laboratory

2013—Current

Research Hydrologist, USDA Forest Service, Southern Research Station, Eastern Forest Environmental Threat Assessment Center

2010—2013

Environmental Program Supervisor, North Carolina Department of Environment and Natural Resources, Division of Water Quality, Environmental Sciences Section, Intensive Survey Unit

2008—2010

Environmental Modeler, North Carolina Department of Environmental and Natural Resources, Division of Water Quality, Planning Section, Modeling and TMDL Unit

2006—2008

Doctoral Research Assistant, North Carolina State University, Department of Forestry and Environmental Resources

2003—2005

Design Engineer, Caterpillar, Inc.

1996—2001

Featured Publications and Products

• Marion, Daniel A.; Sun, Ge; Caldwell, Peter V.; Miniat, Chelcy F.; Ouyang, Ying; Amatya, Devendra M.; Clinton, Barton D.; Conrads, Paul A.; Gull Laird, Shelby; Dai, Zhaohua; Clingenpeel, J. Alan; Liu, Yonqiang; Roehl, Edwin A., Jr..; Moore Myers, Jennifer A.; Trettin, Carl. 2014. Managing forest water quantity and quality under climate change.
• Marion, Daniel A.; Sun, Ge; Caldwell, Peter V.; Miniat, Chelcy F.; Ouyang, Ying; Amatya, Devendra M.; Clinton, Barton D.; Conrads, Paul A.; Gull Laird, Shelby; Dai, Zhaohua; Clingenpeel, J. Alan; Liu, Yonqiang; Roehl, Edwin A., Jr..; Moore Myers, Jennifer A.; Trettin, Carl. 2014. Managing forest water quantity and quality under climate change.
• Sun, Ge; Caldwell, Peter V.; McNulty, Steven G.; Georgakakos, Aris P.; Arumugam, Sankar; Cruise, James; McNider, Richard T.; Terando, Adam; Conrads, Paul A.; Feldt, John; Misra, Vasu; Romolo, Luigi; Rasmussen, Todd C.; Marion, Daniel A. 2013. Impacts of Climate Change and Variability on Water Resources in the Southeast USA.
• Sun, Ge; Caldwell, Peter; McNulty, Steve; Ward, Eric; Domec, Jean-Christophe; Noormets, Asko. 2013. Regional carbon sequestration and climate change: It’s all about water.
• Caldwell, P. V.; Sun, G.; McNulty, S. G.; Cohen, E. C.; Moore Myers, J. A. 2012. Impacts of impervious cover, water withdrawals, and climate change on river flows in the conterminous US.
• Caldwell, P.V.; Vepraskas, M.J.; Gregory, J.D.; Skaggs, R.W.; Huffman, R.L. 2011. Linking plant ecology and long-term hydrology to improve wetland restoration success.

Publications

• Duan, Kai ; Caldwell, Peter V; Sun, Ge ; McNulty, Steven G.; Zhang, Yang ; Shuster, Erik ; Liu, Bingjun ; Bolstad, Paul V. 2019. Data on projections of surface water withdrawal, consumption, and availability in the conterminous United States through the 21st century.
• Chouaib, Wafa ; Alila, Younes ; Caldwell, Peter V. 2019. On the use of mean monthly runoff to predict the flow–duration curve in ungauged catchments.
• Duan, Kai ; Caldwell, Peter V; Sun, Ge ; McNulty, Steven G.; Zhang, Yang ; Shuster, Erik ; Liu, Bingjun ; Bolstad, Paul V. 2019. Understanding the role of regional water connectivity in mitigating climate change impacts on surface water supply stress in the United States.
• Hallema, Dennis; Sun, Ge; Caldwell, Peter; Robinne, Francois-Nicolas; Bladon, Kevin D.; Norman, Steve; Liu, Yongqiang; Cohen, Erika C.; McNulty, Steve. 2019. Wildland fire impacts on water yield across the contiguous United States.
• Zhang, Liangxia ; Sun, Ge ; Cohen, Erika ; McNulty, Steven ; Caldwell, Peter ; Krieger, Suzanne ; Christian, Jason ; Zhou, Decheng ; Duan, Kai ; Cepero-Pérez, Keren J. 2018. An improved water budget for the El Yunque National Forest, Puerto Rico, as determined by the Water Supply Stress Index Model.
• Hallema, Dennis W.; Sun, Ge; Caldwell, Peter V.; Norman, Steven P.; Cohen, Erika C.; Liu, Yongqiang; Bladon, Kevin D.; McNulty, Steven G. 2018. Burned forests impact water supplies.
• Duan, Kai; Sun, Ge; Caldwell, Peter V.; McNulty, Steven G.; Zhang, Yang. 2018. Implications of Upstream Flow Availability for Watershed Surface Water Supply Across the Conterminous United States.
• Chouaib, Wafa ; Alila, Younes ; Caldwell, Peter V. 2018. Parameter transferability within homogeneous regions and comparisons with predictions from a priori parameters in the eastern United States.
• Chouaib, Wafa; Caldwell, Peter V.; Alila, Younes. 2018. Regional variation of flow duration curves in the eastern United States: Process-based analyses of the interaction between climate and landscape properties.
• Jackson, C. Rhett; Webster, Jackson R.; Knoepp, Jennifer D.; Elliott, Katherine J.; Emanuel, Ryan E.; Caldwell, Peter V.; Miniat, Chelcy F. 2018. Unexpected ecological advances made possible by long-term data: A Coweeta example.
• Caldwell, P.V. ; Jackson, C.R. ; Miniat, C.F. ; Younger, S.E. ; Vining, J.A. ; McDonnell, J.J. ; Aubrey, D.P. . 2018. Woody bioenergy crop selection can have large effects on water yield: A southeastern United States case study.
• Duan, Kai; Sun, Ge; McNulty, Steven G.; Caldwell, Peter V.; Cohen, Erika C.; Sun, Shanlei; Aldridge, Heather D.; Zhou, Decheng; Zhang, Liangxia; Zhang, Yang. 2017. Future shift of the relative roles of precipitation and temperature in controlling annual runoff in the conterminous United States.
• Duan, Kai; Sun, Ge; Zhang, Yang; Yahya, Khairunnisa; Wang, Kai; Madden, James M.; Caldwell, Peter V.; Cohen Mack, Erika; McNulty, Steve. 2017. Impact of air pollution induced climate change on water availability and ecosystem productivity in the conterminous United States.
• Cohen, Erika; Sun, Ge; Zhang, Liangxia; Caldwell, Peter; Krieger, Suzanne. 2017. Quantifying the role of forested lands in providing surface drinking water supply for Puerto Rico.
• Hallema, Dennis W.; Sun, Ge; Bladon, Kevin D.; Norman, Steven P.; Caldwell, Peter V.; Liu, Yongqiang; McNulty, Steven G. 2017. Regional patterns of postwildfire streamflow response in the Western United States: The importance of scale-specific connectivity.
• Hain, Ernie F.; Kennen, Jonathan G.; Caldwell, Peter V.; Nelson, Stacy A.C.; Sun, Ge; McNulty, Steven G. 2017. Using regional scale flow-ecology modeling to identify catchments where fish assemblages are most vulnerable to changes in water availability.
• Elliott, Katherine J.; Caldwell, Peter V.; Brantley, Steven T.; Miniat, Chelcy F.; Vose, James M.; Swank, Wayne. 2017. Water yield following forest-grass-forest transitions.
• Caldwell, Peter; Miniat, Chelcy F.; Aubrey, Doug; Jackson, Rhett; McDonnell, Jeff; Krauss, Ken W.; Latimer, James S. 2016. Precipitation partitioning in short rotation bioenergy crops: implications for downstream water availability..
• Hallema, Dennis W.; Sun, Ge; Caldwell, Peter V.; Norman, Steve; Cohen Mack, Erika; Liu, Yongqiang; Ward, Eric J.; McNulty, Steve. 2016. Assessment of wildland fire impacts on watershed annual water yield: Analytical framework and case studies in the United States.
• Tavernia, Brian G.; Nelson, Mark D.; Seilheimer, Titus S.; Gormanson, Dale D.; Perry, Charles H. (Hobie); Caldwell, Peter V.; Sun, Ge. 2016. Conservation and maintenance of soil and water resources.
• Caldwell, Peter V.; Miniat, Chelcy F.; Elliott, Katherine J.; Swank, Wayne. T.; Brantley, Steven T.; Laseter, Stephanie H. 2016. Declining water yield from forested mountain watersheds in response to climate change and forest mesophication.
• Duan, Kai; Sun, Ge; Sun, Shanlei; Caldwell, Peter V.; Cohen Mack, Erika; McNulty, Steve; Aldridge, Heather D.; Zhang, Yang. 2016. Divergence of ecosystem services in U.S. National Forests and Grasslands under a changing climate.
• Vose, James M.; Miniat, Chelcy Ford; Luce, Charles H.; Asbjornsen, Heidi; Caldwell, Peter V.; Campbell, John L.; Grant, Gordon E.; Isaak, Daniel J.; Loheide, Steven P., II.; Sun, Ge. 2016. Echohydrological implications of drought for forests in the United States.
• Sun, Ge; Sun, Shanlei; Xiao, Jingfeng; Caldwell, Peter; Amatya, Devendra; Irmak, Suat; Gowda, Prasanna H.; Panda, Sudhanshu; McNulty, Steve; Zhang, Yang. 2016. Estimating watershed evapotranspiration across the United States using multiple methods.
• McNulty, Steve; Cohen Mack, Erika; Sun, Ge; Caldwell, Peter. 2016. Hydrologic modeling for water resource assessment in a developing country: the Rwanda case study.
• Amatya, Devendra; Campbell, John; Wohlgemuth, Pete; Elder, Kelly; Sebestyen, Stephen; Johnson, Sherri; Keppeler, Elizabeth; Adams, Mary Beth; Caldwell, Peter; Misra, D. 2016. Hydrological processes of reference watersheds in Experimental Forests, USA.
• Caldwell, Peter; Miniat, Chelcy Ford; Brantley, Steven; Elliott, Katherine; Laseter, Stephanie; Swank, Wayne. 2016. Long term records provide insights on the relative influence of climate and forest community structure on water yield in the southern Appalachians.
• Sun, Shanlei; Sun, Ge; Cohen Mack, Erika; McNulty, Steve; Caldwell, Peter V.; Duan, Kai; Zhang, Yang. 2016. Projecting water yield and ecosystem productivity across the United States by linking an ecohydrological model to WRF dynamically downscaled climate data.
• Hallema, Dennis W.; Sun, Ge; Caldwell, Peter V.; Norman, Steve; Cohen, Erika C.; Liu, Yongqiang; McNulty, Steve. 2016. Relationships between wildland fires and watershed hydrology across the contiguous U.S.
• Caldwell, Peter V.; Kennen, Jonathan G.; Sun, Ge; Kiang, Julie E.; Butcher, Jon B.; Eddy, Michele C.; Hay, Lauren E.; LaFontaine, Jacob H.; Hain, Ernie F.; Nelson, Stacy A. C.; McNulty, Steve G. 2015. A comparison of hydrologic models for ecological flows and water availability.
• McNider, R.T.; Handyside, C.; Doty, K.; Ellenburg, W.L.; Cruise, J.F.; Christy, J.R.; Moss, D.; Sharda, V.; Hoogenboom, G.; Caldwell, Peter. 2015. An integrated crop and hydrologic modeling system to estimate hydrologic impacts of crop irrigation demands.
• Sun, Shanlei; Sun, Ge; Caldwell, Peter; McNulty, Steven G.; Cohen, Erika; Xiao, Jingfeng; Zhang, Yang. 2015. Drought impacts on ecosystem functions of the U.S. National Forests and Grasslands: Part I evaluation of a water and carbon balance model.
• Sun, Shanlei; Sun, Ge; Caldwell, Peter; McNulty, Steve; Cohen, Erika; Xiao, Jingfeng; Zhang, Yang. 2015. Drought impacts on ecosystem functions of the U.S. National Forests and Grasslands: Part II assessment results and management implications.
• Schwalm, C.R.; Huntzinger, D.N.; Cook, R.B.; Wei, Y.; Baker, I.T.; Neilson, R.P.; Poulter, B.; Caldwell, Peter; Sun, G.; Tian, H.Q.; Zeng, N. 2015. How well do terrestrial biosphere models simulate coarse-scale runoff in the contiguous United States?.
• Sun, Ge; Caldwell, Peter. 2015. Impacts of urbanization on stream water quantity and quality in the United States.
• Emanuel, Ryan E; Buckley, John J; Caldwell, Peter V; McNulty, Steve; Sun, Ge. 2015. Influence of basin characteristics on the effectiveness and downstream reach of interbasin water transfers: displacing a problem.
• Sun, Ge; Caldwell, Peter V.; McNulty, Steven G. 2015. Modelling the potential role of forest thinning in maintaining water supplies under a changing climate across the conterminous United States.
• Fang, Yuan; Sun, Ge; Caldwell, Peter; McNulty, Steven G.; Noormets, Asko; Domec, Jean-Christophe; King, John; Zhang, Zhiqiang; Zhang, Xudong; Lin, Guanghui; Zhou, Guangsheng; Xiao, Jingfeng; Chen, Jiquan. 2015. Monthly land cover-specific evapotranspiration models derived from global eddy flux measurements and remote sensing data.
• Sun, S.; Sun, Ge; Cohen Mack, Erika; McNulty, Steve; Caldwell, Peter; Duan, K.; Zhang, Y. 2015. Predicting future US water yield and ecosystem productivity by linking an ecohydrological model to WRF dynamically downscaled climate projections.
• Caldwell, Peter; Segura, Catalina; Laird, Shelby Gull; Sun, Ge; McNulty, Steven G.; Sandercock, Maria; Boggs, Johnny; Vose, James M. 2015. Short-term stream water temperature observations permit rapid assessment of potential climate change impacts.
• Segura, Catalina; Caldwell, Peter; Sun, Ge; McNulty, Steve; Zhang, Yang. 2014. A model to predict stream water temperature across the conterminous USA.
• Vose, James M.; Miniat, Chelcy F.; Sun, Ge; Caldwell, Peter V. 2014. Potential implications for expansion of freeze-tolerant eucalyptus plantations on water resources in the southern United States.
• Caldwell, Peter; Muldoon, Corinne; Ford-Miniat, Chelcy; Cohen, Erika; Krieger, Suzanne; Sun, Ge; McNulty, Steven; Bolstad, Paul V. 2014. Quantifying the role of National Forest system lands in providing surface drinking water supply for the Southern United States.
• Johnson-Gaither, cassandra; Schelhas, John; Zipperer, Wayne; Sun, Ge; Caldwell, Peter V.; Poudyal, Neelam. 2014. Water stress and social vulnerability in the southern United States, 2010-2040.
• McNulty, Steve; Moore Myers, Jennifer; Caldwell, Peter; Sun, Ge. 2013. Climate change summary.
• McNulty, Steven; Caldwell, Peter; Doyle, Thomas W.; Johnsen, Kurt; Liu, Yongqiang; Mohan, Jacqueline; Prestemon, Jeffrey; Sun, Ge. 2013. Forests and Climate Change in the Southeast USA.
• Lockaby, Graeme; Nagy, Chelsea; Vose, James M.; Ford, Chelcy R.; Sun, Ge; McNulty, Steve; Caldwell, Pete; Cohen, Erika; Moore Myers, Jennifer . 2013. Forests and water.
• Averyt, K.; Meldrum, J.; Caldwell, P.; Sun, G.; McNulty, S.; Huber-Lee, A.; Madden, N. 2013. Sectoral contributions to surface water stress in the coterminous United States.
• Tavernia, Brian G.; Nelson, Mark D.; Caldwell, Peter; Sun, Ge. 2013. Water stress projections for the northeastern and Midwestern United States in 2060: anthropogenic and ecological consequences.
• Lockaby, Graeme; Nagy, Chelsea; Vose, James M.; Ford, Chelcy R.; Sun, Ge; McNulty, Steve; Caldwell, Pete; Cohen, Erika; Moore Meyers, Jennifer. 2011. Chapter 13: Water and Forests.
• McNulty, Steve; Moore Myers, Jennifer; Caldwell, Peter; Sun, Ge. 2011. Chapter 3: Climate Change.

Research Highlights

Quantifying the Role of National Forest System Lands in Providing Surface Drinking Water Supply for the Southern United States (2014)

In the South, as in the rest of the U.S., people and communities depend on forests as the headwaters for clean and dependable water supply. A new publication by U.S. Forest Service researchers provides details at the landscape level on the quantity of water southern communities receive from federal, state and private forest lands. The report provides, for the first time, scientifically credible information on the exact extent and importance of forests to drinking water in the South.

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Water yield following forest to grass to forest transitions (2017)

Forested watersheds are important sources of drinking water. However, species identity affects water yield from deciduous forests. Through old-field succession, changes in species composition over time determine how much precipitation leaves the watershed as evapotranspiration versus water yield.

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