Photo of Ge Sun

Ge Sun

Research Hydrologist and Project Leader
P.O. Box 12254
3041 East Cornwallis Road
Research Triangle Park, NC 27709-2254
Phone: 919-549-4070

Current Research

  • Modeling the potential effects of climate change, landuse change, population growth, and urbanization on water supply and demand in the conterminous United States (CONUS)
  • Water use (Evapotranspiration) of southern forests 
  • Measuring and modeling carbon and water fluxes
  • Hydrological effects of longleaf pine restoration in the southern U.S.
  • Effects of precribed burning on water quality
  • Hydrologic effects of forest conversion from hardwood forests to pine plantations 

Research Interests

  • Effects of climate change and land management on water quantity and quality, and water supply and demand at a regional scale 
  • Application of computer simulation models, GIS, and remote sensing in regional hydrology
  • Evapotranspiration and ecosystem productivity modeling  
  • Forest benefits to mitigate extreme climatic impacts (floods and droughts)
  • Effects of urbanization on watershed hydrology and climate 

Past Research

I have worked on various forest hydrology projects in different geophysical settings around the world to understand natural and human impacts on watershed water balances and processes. Models (FLATWOODS, PnET, MIKE SHE, WaSSI), remote sensing, and GIS data have been used to synthesize station-based information toward generalizing and projecting hydrological consequences from disturbances at broader scales and answer practical 'what if' management questions.

Why This Research is Important

Water is the most fundamental component of life. Forests and water are intimately linked at multiple spatial and temporal scales. Global changes in climate and land use have profound impacts on the quantity, quality, and timing of water on Earth. Understanding forest-water-climate-people interactions is critical for sustainable management and conservation of natural resources, and adaptationto environmental change in the 21st century.


Ph.D. in Forest Hydrology and Watershed Management, 1995
University of Florida
M.S. in Forest Hydrology, 1988
Beijing Forestry University
B.S. in Soil and Water Conservation, 1985
Beijing Forestry University

Awards and Recognition

Icko Iben Multidisciplinary Communications Award from American Water Resources Association, 2021
Established in 1971, this award recognizes persons who have made outstanding contributions in promoting communication among the various disciplines concerned with water resources issues.
US Forest Service Research & Development Deputy Chief Award's Distingushed Science Award, 2017
Sustained productivity and leadership in forest hydrology research
US Forest Service Chief's Honor Award, 2017
Applying Knowledge Globally; Forests and Water in a Changing Environment
Source Water Protection from North Carolina Source Water Collaborative (Team award), 2017
for Defining and Understanding How Forests Protect Watersheds and Source Water.
Southern Research Station Director's Distinguished Science Award, 2016
Leadership and productivity in forest hydrology research
Certificate of Appreciation, 2016
An author of "Understanding the Impacts of Drought on the Nation's Forest and Grasslands: Providing a Scientific Foundation for Effective Management Responses", which Received a 2016 Chief's Award for the Category of Sustaining Forests and Grasslands
Fellow of American Water Resources Association, 2015
For outstanding serve to AWRA and an eminent record in forest water resources science and technology.
USFS Southern Research Station Director's Global Stewardship Award, 2009
For global applications of hydrological science and technology

Featured Publications and Products


Research Highlights

Burning forests can impact water supplies (2017)
SRS-2017-145 The number of wildland fires and burned areas in the U.S. is on the rise as a result of a warming climate, drought, and increasing human ignitions. Although forests and rangelands provide more than half of U.S. water supplies, the long-term impacts of both wildland and prescribed fire on water supplies have not been previously measured nor factored into water management strategies. Forest Service researchers developed a practical framework to evaluate fire impacts on water resources by synthesizing 30-year-old records of wildland fire, climate, and river flow for 162 locations across the U.S.

Climate Change Impacts on Ecosystem Services: water, carbon, and biodiversity (2010)
SRS-2010-015 SRS is enhancing one of its models that examines the potential impacts of climate change, land use, and population changes on water supplies. The researchers are building this integrated, water-centered modeling on previous water supply and demand research that resulted in a Water Supply Stress Index (WaSSI) model.

Fertilized Pines Use Water More Efficiently But May Suffer Worse in Droughts (2015)
SRS-2015-235 Fertilized loblolly pine trees produce more wood than their unfertilized counterparts, even when less water was available, butthis may also indicate that fertilized pine plantations are more vulnerable to severe drought.

Forests to Faucets: Visualizing Forests’ Role in Supplying Drinking Water Across the U.S. (2020)
SRS-2020-19 Forests provide drinking water and protect drinking water supplies. The USDA Forest Service's 'Forest to Faucets' program is a unique tool for understanding and visualizing this ecosystem service, as well as the stressors that threaten it. This new, user-friendly tool integrates maps, hydrologic models, and databases of surface drinking water supply across the country.

High Forest Productivity Often Comes at the Expense of Soil Carbon Storage (2015)
SRS-2015-250 Forest Service scientists and their research partners are studying the role of managed forests in regional carbon, water, and energy exchange to understand how managed forests contribute to land-atmosphere feedbacks and climate dynamics.

Impacts of wildland fires on U.S. freshwater resources are variable (2018)
SRS-2018-61 Burning forests alters watershed hydrological cycles by modifying soil and forest cover properties. Researchers found that fires with moderate or high burn severity contributed most to increased river flows, while prescribed fires had little effect on water yield for large basins. Climate variability, including drought, may mask the effects of wildland fire on water supplies, so effective forest management practices must consider local watershed conditions.

International collaborators develop easy-to-use formulas for water and carbon accounting (2017)
SRS-2017-148 Ecosystem water use is closely coupled with ecosystem productivity, water availability, and water supplies, but accurate water use accounting remains challenging because of model deficiencies or difficulty of model use in practice. Forest Service researchers combined global water use or evapotranspiration measurements with remote sensing products to create a series of simple formulas that can accurately estimate water use and thus water and carbon budgets for seven different land cover types. This work improves understanding of the connections between forest management practices, carbon and water cycles, and changing climate conditions.

Quantifying the Role of State and Private Forest Lands in Providing Surface Drinking Water Supply for the Southern U.S. (2020)
SRS-2020-33 Forested land owned by states or private and family owners makes up about 44 % of the total land area in the South. This study highlights the connection between state and private forests (SPF) and the drinking water supply in the South. The study reveals that SPF lands contributed more than 44 %of the water supply generated in the region.

Southern forested wetlands are projected to become drier in the future (2018)
SRS-2018-56 Extensive southern forested wetlands provide important ecosystem services. A study of five typical forested wetlands across the Southeast suggests that these wetlands will likely become drier or may even disappear by the end of this century under severe climate change scenarios. This information can help land managers develop climate change mitigation and adaptation methods to protect these important natural resources.

Tools to help international conservation agencies make sound decisions (2011)
SRS-2011-02 Researchers with the Eastern Forest Environmental Threat Assessment Center (EFETAC) applied models they developed with partners to measure water supply stress in relation to carbon and biodiversity and to evaluate ecosystem services to several locations in Africa-Nyungwe National Park, Rwanda; Ruaha River Watershed, Tanzania; and Luangwa Valley, Zambia-to look at the potential impact of land use practices on water quality and quantity. These tools can be used by conservation agencies in any location worldwide to make sound decisions. This research is also important because the African ecosystems where these models are being applied are ecosystems that could potentially develop in the United States in the future due to the impacts of climate change.

R&D Affiliations
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External Resources