Photo of Devendra M. Amatya

Devendra M. Amatya

Research Hydrologist
3734 Highway 402
 Cordesville, SC 29434
Phone: 843-336-5612
Fax: 843-336-5068
devendra.m.amatya@usda.gov

Current Research

- to examine the watershed-scale effects of longleaf pine (Pinus palustris) restoration on hydrology, particularly the water yield, using a paired watershed system. Restoration of longleaf pine (LLP) ecosystems is one of the principal land management objectives throughout the southeastern U.S., including the recently approved Francis Marion National Forest Plan. While there have been numerous studies regarding the restoration techniques and the associated responses of ecosystem services, and studies on individual trees or small plots for their water use, major uncertainty lies in the effects on the watershed-scale forest water balance, in contrast with loblolly pine (Pinus taeda L.). The linkage between LLP restoration and water is particularly important as regional demands on water resources increase, along with uncertainties regarding supplies. The principal hypothesis guiding this study is that LLP restoration will result in water yield increase from the watershed primarily due to lower understory density resulting in higher water table (WT) and soil moisture (SM) compared to existing loblolly pine stands. The study is testing these hypotheses using both the SM and WT monitoring on various stands to be manipulated within the treatment watershed as well as using a paired watershed approach to quantify the watershed-scale effects on water yield at Santee Experimental Forest. In addition, a field data validated modeling approach is being conducted to project the yield for near-future climate scenarios using ensemble of climate change models to address uncertainties in the yield and vulnerability of pine ecosystem as affected by changing climate.
- To evaluated potential impacts of high precipitation events on peak discharges and road cross drainage structures at Forest Service Experimental Forests. In the absence of site specific precipitation intensity-duration-frequency (PIDF) data, NOAA data are frequently used for estimating peak discharges for sizing the culverts and to assess their vulnerability to extreme rainfall events. The study is testing the hypothesis that the PIDF data from on-site rain gauges at the long-term EFRs will be different from the NOAA data with consequences to road cross-drainage structures, their installation costs, life span, and vulnerability. Furthermore, uncertainty in the peak discharge estimates by using multiple widely used models and vulnerability assessment of critical areas are being considered. 
- To undesrtand the coastal forest hydrology complicated by its interaction with the downstream tidal wetlands, the interface between marine and terrestrial ecosystems that is directly impacted by sea level rise and climate change. Little is known about the ecohydrological processes, functions and ecosystem services provided by these important and widely-distributed wetlands. Not only is the bi-directional tidal flow monitoring complex warranting cumbersome field methods with advanced sensors but also the interaction of downstream tidal forcing with the upland freshwater discharge makes the understanding of process mechanisms on this intertidal wetland more challenging. A study is being initiated at the Santee Experimental Forest, with a baseline data from upland freshwater forested watersheds that drain into the tidal Huger Creek, headwaters of Cooper River draining to Charleston Harbor, to address this un-studied portion of the coastal plain landscape. For example, one of the proposed hypotheses is that higher groundwater levels due to extended flooding of the tidal system will result in higher soil moisture, ET, and more C sequestration.
- Quantification of water balance (particularly evapotranspiration) and nutrient balance of natural and drained managed pine forests including with intercropping practices on coastal plain.

Research Interests

- Understanding hydrologic processes, transport and interactions in forested wetlands
- Quantifying hydrologic budgets of freshwater and tidally influenced forested wetlands (naturally drained and managed forests);
- Hydrologic and water quality studies on effects of land and water management, prescribed/wild fire, land use change, climate variability and change, sea level rise, and extreme events on low-gradient coastal landscapes from freshwater to tidally affected landscapes using monitoring and modeling approaches
- Determining effects of extreme events on the hydrology/water quality of forested watersheds;
- Specific research on runoff and evapotranspiration dynamics of coastal forests (freshwater and tidal)
- Assessment of long-term trends and variability in hydrology and their potential applications in developing and testing hydrology and water quality models for terrestrial freshwater lands linked to the downstream tidal marshes/estuaries
- Application of remote sensing tools and products for watershed hydrologic modeling
- Specific modeling tools for research: DRAINMOD, SWAT, MIKESHE, and SWMM

Past Research

1992- 2002:

Field istrumentation, data monitoring, hydrologic & hydraulic analyses, design of data acquisition system and database management for hydro-meteorologic and water quality data including GIS related spatial data; hydrologic and water quality modeling of large watershed with complex landuse in the coastal plain of eastern North Carolina;  

 

Field experimental studies and modeling of hydrology and water quality of poorly drained loblolly pine stands during its life cycle;

 

Study of ditch and canal hydraulics, flow measuring and control structures and their effects on hydrology, water management and water quality of the poorly drained soils on wet flats;

 

Development of a comprehensive data base linked with GIS on hydro-meteorology, soils, vegetation, water quality, water and land use management practices for a complex coastal watershed;

 

Data analyses and development, evaluation and modification of hydrologic/ water quality models (distributed and lumped) for drained forested and agricultural watersheds;

 

Study of hydrologic, hydraulic and water quality impacts of various land and water management practices on drained agricultural and forested stands on the field as well as watershed scale;

 

Development of World Wide Web Home Page in the Internet http:// www.bae.ncsu.edu/research/soil_water/www/watmngmnt/) for Water Management Research Program led by Dr. Wayne Skaggs;

 

Experimental Study, development and evaluation of evapotranspiration models as related to different vegetative stands;

 

Evaluation and identification of wetland hydrology;

Why This Research is Important

Landuse and landcover change dramatically affects the water yield and contaminant loads. Depletion of wetlands along the Southeastern coastlines primarily due to urban sprawl is becoming a bigger environmental threat causing loss of habitats, potential flooding, and degradation of water quality. Hydrology in terms of water table below ground surface is one of the primary indicators of wetland hydrology restoration. The long-term water table data analysis is critical for understanding the seasonal and temporal variability, frequency and duration of moisture/ponding on various types of soils and vegetation. Information derived by using the long-term data from the Santee Experimental Forest watersheds helped reveal the critical phenomenon on a possible flow reversal after Hurricane Hugo (1989) on these watersheds due to temporal and spatial change in vegetation. Quantity and quality of seasonal freshwater outflows can also be an indicator of whether saltwater intrusion has occurred and the sufficient freshwater inflows are discharged for maintenance of low-salinity waters in estuarine areas with fisheries habitat. Such information is critical for area land owners, land developers/managers including the National Forest in the region for assessment and restoration of ecosystem functions, and adapting needed management practices.While the LT data and models from artificially drained watersheds at Weyerhaeuser's experimental pine forest in North Carolina provided a baseline information on hydrology and water quality of managed pine forests, effects of water and silvicultural treatments used for productivity, these LT data with current monitoring have also become a foundation to test hypotheses on effects of managing pine forest intercropped with switchgrass (cellulosic biofuel). Recent developments in changing environment will put even more demands on such data for generating new hypotheses on water and energy demand/supply, climate change and sea level rise, and eco-system services. Due to limited resources for monitoring for a long period and of all environmental variables models are being used to quantify the water balance, water table and runoff dynamics, biogeochemical cycling including the GHGs and contaminant transport, and their complex interactions with climate, topography, soil, vegetation, and land use at spatial and temporal scales at which monitoring is sometimes impractical.

Education

Ph.D. in Soil & Water, 1993
North Carolina State University
M.S. in Hydrology, 1985
Duke University
M.Sc. in Hydrotechnical, 1974
Lumumba University

Professional Experience

Research Hydrologist, USDA Forest Service, Center for Forested Wetlands Research
2002—Current

- Develop a multi-collaborative hydrology research program focused mainly on coastal low-gradient forested landscapes - Oversee the long-term hydrometeorologic and water quality studies on four guaged watersheds on the Santee Experimental Forest. - Identify and coordinate multi-collaborative hydrologic research, prioritize objectives, design and develop strategies including appropriate innovative field monitoring, analysis, and modeling tools for addressing contemporary coastal hydrology issues. - Assist in database management, quality control and accessibility, and data sharing with cooperators

Research Assistant Professor, North Carolina State University, Biolgical & Agricultural Engineering. Dept.
1998—2002

- Effects of controlled drainage on storm event hydrology of managed pine forests; - Development and application of DRAINMOD-based watershed-scale models of various levels of complexities for evaluating drainage outflow and nutrient loading from drained managed pine forests - Developing curriculum for Advanced Hydrology and Water Quality Modeling on Drained Forest Lands - Teaching the above modeling course to MS and PhD level students - Presenting and publishing research results; Contributing to collaborative research grant proposals

Postdoctoral Research Associate, North Carolina State University, Biolgical & Agricultural Engineering. Dept.
1994—1998

- Assessment of forest potential evapotranspiration; - Evaluation of controlled drainage on forest water quantity & quality; - Field and watershed-scale modeling of drained forest lands; - Water balance of a natural forest wetland using monitoring and DRAINMOD-based watershed-scale model

Awards and Recognition

Forest Service Southern Research Station Director's Distinguished Scientist Award, 2020
For significant contributions advancing understanding the hydrology of wetland forests and the impacts of the management activities to ensure sustainability.
Honor and recognition, 2018
as a 2018 Fellow Member for significant contributions made to the profession and the high regard the Society members hold the Fellow member by the American Society of Agricultural Engineers (ASABE) at the July 30, 2018 ASABE Annual International Meeting i
US EPA’s Scientific and Technological Achievement Award, 2018
for a paper on "Hydrologic connectivity between geographically isolated wetlands and surface water systems: A review of select modeling methods" published in Journal of Environmental Modeling & Software in 2014
Forest Service Southern Research Station Director’s Sabbatical Award, 2017
Sabbatical for five months research in 2018 on Innovative monitoring and modeling methods on a Restored Tidal Wetland at the University of Antwerp, Antwerp in Belgium.
Letter of Appreciation by The Geological Society of America, 2016
For serving as a Mentor for the John Mann Mentors Program in Applied Hydrogeology
Letter of Appreciation by Clemson University, 2016
For commitment and leadership in serving as a planning committee member for the past five conferences of SC Water Resources Conference as well as in encouragement/guidance for creating a new Journal of South Carolina Water Resources.
Letter of Recognition by US Department of Energy, 2016
For contribution to a Chapter 6 on Water Quality Effects of Biomass Removal for Bioenergy in the 2016 Billion Ton Report Volume 2: Environmental Sustainability Effects
Certificate of Appreciation by USDA Forest Service, 2015
For exceptional effort and dedication to the effort to develop important technical resources that improve the Agency’s capacity to meet its stewardship responsibilities for groundwater resources on Natural Forests and Grasslands.
Outstanding Leadership Award, 2014
Recognized by the ASABE for an outstanding leadership in serving as a Co-Chair of the ASABE’s 2014 International Evapotranspiration Symposium on April 7-10, 2014 in Raleigh, NC
U.S. Fulbright Fellowship, 2010
U.S. Fulbright Fellowship Award for Research and Lectures at Krakow Agricultural University (November 2010- January 2011) and Warsaw University of Life Sciences (January - March 2011) both in Poland
Certificate of Merit, 2009
Forest Service Southern Research Station Director’s Certificate of Merit for Effective Partnerships in Hydrologic Research on the Santee Experimental Forest
Southern Research Station Directors’ 2007 Partnership Award, 2007
Forest Service Southern Research Station Directors’ 2007 Partnership Award for vision, initiative and effectiveness in establishing the Turkey Creek Research Partnership, an important foundation of the Stations’ watershed sciences program.
Outstanding Leadership Award, 2006
Outstanding Leadership Award and President's Citation by the American Society of Agricultural and Biological Engineers for the leadership of Co-chairing the 2006 International Conference on Hydrology and Management, New bern, NC
Certificate of Appreciation, 2002
Certificate of Appreciation for Distinguished Service to Water Management Group and Biological and Agricultural Engineering Department at North Carolina State University from 1989 – 2002.

Featured Publications and Products

Publications

Research Highlights

Impacts of Different Management and Disturbance Histories on the Hydrology of Atlantic Coastal Plain Forests (2020)
SRS-2020-58 Shallow water tables respond rapidly to rainfall and evapotranspiration, making runoff in coastal forests highly variable. However, new SRS research on two very different forests found that they had similar runoff responses to extreme climatic events. Long-term monitoring is key to understanding how climate and vegetation management affect runoff.
Long-term Water Table Dynamics of Forested Wetlands in the Southeastern Atlantic Coastal Plain (2019)
SRS-2019-43 As federal jurisdiction over isolated wetlands continues to be a subject of debate, it is critical that drivers of wetland hydrology be properly identified and evaluated in coastal forested wetlands. Wetland hydrology exists on a site if, during the growing season, the water table is normally within about a foot of the surface for a continuous critical duration. Results from this USDA Forest Service study assessing wetland hydrology from multisite and multiyear data have implications for the restoration of coastal wetland forests. The results also will inform modeling studies on wetland hydrology as affected by human and natural disturbances.
Water quality effects of switchgrass intercropping on pine forests in coastal North Carolina (2017)
SRS-2017-151 Six recent years of data from site preparation to full growth of switchgrass, as a celluolosic bioenergy crop, suggest that planting switchgrass between loblolly pine tree beds improved downstream nutrient water quality when compared to a traditional managed pine forest at a North Carolina Coastal Plain site. However, a switchgrass only treatment yielded higher nitrogen levels than the intercropped site.
R&D Affiliations
Research Topics
Priority Areas
SRS Science Area
Experimental Forests and Ranges
External Resources
  • The sites listed below are third-party sites which the Forest Service has provided for reference only.
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