2016 Future Wetland Mapping Consortium Webinar Schedule

The WMC Steering Committee organizes bi-monthly webinars on topics of interest to the group. These webinars are held on the third Wednesday of every month at 3:00 p.m. eastern standard time (2:00 p.m. central, 1:00 p.m. mountain and 12:00 p.m. pacific). 

If you haven’t used Go To Webinar before or you just need a refresher, please view our guide prior to the webinar here.  

The Wetland Mapping Consortium is busy working on confirmation of webinar topics and presenters for 2016. Below you will find a draft list of future webinars to give you an idea of what we’re working on. Topics and dates are subject to change. 

3 Part Webinar on the Soil and Water Assessment Tool (SWAT)

Wednesday, July 20, 2016 3:00pm eastern



Role of Prior Converted Croplands on Nitrate Processing in Agricultural Landscapes - Gregory McCarty, PhD, Research Soil Scientist, USDA

Prior converted croplands (PCC) are wetlands that were drained for crop production prior to the Swampbuster provisions of the 1985 Food Security Act.  Within the Swampbuster provisions, PCC’s will revert to wetlands if the land is not cropped for five years and as such they hold special status within agricultural ecosystems for conservation.   Our research has found that although PCC’s are sufficiently drained for crop production, they still retain some of the biogeochemical characteristics of wetlands because of both intrinsic (soil) and extrinsic (landscape position) properties.  We find evidence that the amount of nitrate exported from agricultural watersheds can be related to extent of crop production on hydric soils associated with PCCs.  We hypothesize that this relationship is due to increased ability of PCC’s to process nitrate before leaching to groundwater.   The SWAT model has now been successfully modified to better reflect the unique role PCC’s play in mitigating nitrate export for agricultural production systems.     This work also emphasizes the need to better map the location of PCC’s in agricultural ecosystems both for conservation and for understanding the fate of agricultural nitrogen.    

Watershed-scale hydrologic simulation of geographically isolated wetlands: methods and preliminary results - Grey Evenson, PhD, Post-Doctoral Fellow, Virginia Tech and Visiting Scientist, U.S. EPA

Geographically isolated wetlands (GIWs), defined as wetlands surrounded by uplands, provide an array of ecosystem goods and services. Within the United States, federal regulatory protections for GIWs are contingent, in part, on the quantification of their singular or aggregate effects on the hydrological, biological, or chemical integrity of waterways regulated by the Clean Water Act (CWA).  However, limited tools are available to assess the downgradient effects of GIWs. We modified the Soil and Water Assessment Tool (SWAT), a popular watershed-scale hydrologic model, to incorporate an improved representation of GIW hydrologic processes and thereby evaluate the watershed-scale hydrologic effects of GIWs on downgradient hydrology. This webinar will review (1) our approach to incorporating National Wetland Inventory (NWI) delineated GIWs into SWAT; (2) our method of re-defining SWAT Hydrologic Response Units (HRUs) boundaries to conform to the boundaries of NWI delineated GIWs while simulating fill-spill inter-GIW hydrologic flows; and (3) preliminary results from the application of our modeling approach in the ~1,700 km2 Pipestem watershed in the Prairie Pothole Region of North Dakota. Our approach to modifying SWAT may be replicated to evaluate the watershed-scale aggregate hydrologic effects of GIWs in different watersheds and physiographic regions.

Integration of remote sensing data into a watershed-scale wetland modeling for an improved model prediction - Sangchul Lee, PhD, Candidate, University of Maryland

Wetlands provide important ecological benefits for biodiversity and water quality. This ecosystem functioning highly relies on the hydrological characteristics of wetlands (e.g., hydro-period) and their connectivity to the downstream waters. Soil and Water Assessment Tool (SWAT), one of widely used watershed models, has been applied to investigate catchment-scale wetland hydrological function. However, uncertainties associated with wetland parameterization and the prediction of inundated areas have not been thoroughly assessed due to the data unavailability.  Remote sensing provides synoptic information on the spatial distribution of wetland, and recent studies demonstrated improved capability to characterize wetland inundation patterns at a high resolution (30-m) using time series Landsat records and LiDAR.   This study integrated remote sensing data into Soil and Water Assessment Tool (SWAT) to improve the wetland parameterization and prediction on inundated area and to assess the cumulative hydrological impacts of wetlands on the downstream water.  We adopted Riparian wetland module (RWM), a SWAT extension for riparian wetlands, to simulate interactions between RWs and nearby streams. We will illustrate how inundation maps (derived from satellite remote sensing) can be used to set up spatially varying wetland parameters and to assess predicted inundation at the landscape scales, considering the assumptions and simplification of wetland processes represented in SWAT.  Using the Choptank Watershed as a case study, we will demonstrate the hydrological benefits of wetlands to stabilize overall flow pattern and reduce peak flow at the storm event.


Greg McCarty is a research soil scientist at the USDA ARS Hydrology and Remote Sensing Laboratory in Beltsville MD. Dr. McCarty is a recognized authority on movement and fate of carbon in agricultural landscapes.  Dr. McCarty investigates biogeochemical processes affecting transformation of nitrogen and carbon in agricultural crop fields and adjacent ecosystems such as riparian buffer wetlands.   He also leads the Choptank River Watershed project on the Eastern Shore of Maryland which is part of the USDA Long-term Agroecosystem Research network.  With this project, conservation practices are being assessed at the watershed scale by use of a combination remote sensing and modeling. 

Grey  R. Evenson, Ph.D. is a post-doctoral fellow with Virginia Tech’s Department of Forest Resources and Environmental Conservation and a Visiting Scientist with the US EPA’s Office of Research and Development. He specializes in the simulation of wetland hydrologic effects at larger spatial scales as well as wetland conservation and restoration planning methods. Grey completed his Ph.D. in Geography at Ohio State University in 2014. He lives with his wife and two fat cats in Columbus, Ohio.

Sangchul Lee earned his bachelor and master degree from South Korea and is working toward his PhD at the department of Geographical Sciences in the University of Maryland, College Park. He is interested in assessing the long-term impacts of winter cover crops and wetlands on agricultural watersheds using a watershed model. He integrated remote sensing data into a watershed model to better represent physical processes and improve model predictions.

Past Webinars