Tanja N Williamson, PhD
eSoil-water scientist experienced in natural and human-affected systems, including links with vegetation and landscape dynamics. Research interest spans landscape and water-resource effects of agriculture, mining, development, and climate change. Published research supported by OSMRE, USDA, NSF, USEPA, USGS, state agencies, and universities.
Biography
Recent and ongoing research includes:
- Hydrologic modeling of mixed land-use watersheds
- the importance of land-cover change to streamflow magnitude, variability, and seasonality
- developing decision-support systems that inform resource managers
- Incorporation of soil-physical data into hydrologic modeling
- Comparison of lab and field measurements to modeled soil properties
- Sensitivity of hydrologic models to changes in soil properties
- Simulation of hydrologic response from landscape reconstruction
- Temporal variability of soil-water storage and movement
- Agricultural resilience under projected climate change
- Delineation of ephemeral and intermittent streams in Appalachia
- Conservation management in agricultural landscapes
- Identifying sediment source
- Linking soil-water storage with the stream environment
- Extent and characteristics of tile-drains (sub-surface agricultural drainage)
Education
Ph.D. Soil and Water Science (Pedology), University of California, Riverside, 1999
M.S. Earth Science (Geomorphology), University of California, Riverside, 1995
B.S. Geoscience, The Pennsylvania State University, 1992 (includes PSU Field Camp)
Professional Experience
U.S. Geological Survey
- Research Hydrologist, Kentucky Water Science Center (2010 to present)
- Hydrologist, Kentucky Water Science Center (2006 to 2010)
Adjunct Assistant Professor, Department of Plant and Soil Sciences, University of Kentucky (2016 to present)
Quinte Conservation, Belleville, ON, Canada (2006)
Loyalist College, Belleville, ON, Canada (2004-2005)
University of the Pacific, Stockton, CA, Geosciences (1999-2004)
Science and Products
Using machine learning to map topographic-soil & densely-patterned sub-surface agricultural drainage (tile drains) from satellite imagery
In the mid-1800s, tile-drains wereinstalled in poorly-drained soils of topographic lows as watermanagement to protectcropland during wet conditions; consequently, estimations of tile-drain location have been based on soil series. Most tile drainsare in the Midwest, however each state has farms with tile and tile-drain density has increased in the last decade. Where tile drains quickly remove...
Agriculture Best Management Practices: Quantification of In-Stream Phosphorus and Sediment Storage and Transport - Linking Land Use and Landscape Best Management Practices with Downstream Transport in Great Lakes Restoration Initiative Priority Watersheds
As part of a coordinated effort with University of Minnesota (UMN) and US Forest Service (USFS), USGS will conduct sediment and phosphorus source tracking in two agricultural watersheds -- specifically corn and soybean production -- of Black Creek and Plum Creek, tributaries to the Maumee and Fox Rivers, respectively.
Environmental Effects of Agricultural Practices
As agricultural land in the Minnesota River Basin is retired, tile drains are removed or broken and riparian corridors are planted to reduce runoff. Early studies saw decreased sediment and nitrogen and improved biological indicators but no significant changes in phosphorus. This project continues to investigate the linkages...
Simulation of Soil-Water Availability
How much water is stored in the soil? Does agricultural management affect this? Will this change if temperatures increase and plants need more water?
In order to answer this question, we have focused on the differences in soil physical properties under four land management types (forest, pasture, traditional agriculture, and conservation agriculture) and whether these differences...
Unmanned Aircraft Systems
The USGS Ohio-Kentucky-Indiana Water Science Center has become a regional leader in using Unmanned Aircraft Systems (UAS), also known as drones, for mapping and hazards analysis.
Monthly suspended-sediment apportionment for a western Lake Erie agricultural tributary
Black Creek, a headwater to the Maumee River and western Lake Erie, is an agricultural basin with a mix of cropland (66%), pasture (19%), and forest (7%) linked by a road network to the rural community. Suspended sediment was collected monthly during the 2018 water year for the main stem and two sub-basins using in-situ, passive samplers that...
Williamson, Tanja N.; Dobrowolski, Edward G.; Gellis, Allen; Sabitov, Timur; Gorman Sanisaca, LillianHydrologic modeling to examine the influence of the forestry reclamation approach and climate change on mineland hydrology
Forests in the Appalachian region of the U.S. are threatened by a variety of short- and long-term pressures, including climate change, invasive species, and resource extraction. Surface mining for coal is one of the most important drivers of land-use change in the region, reducing native forest cover, causing forest fragmentation, eliminating...
Williamson, Tanja N.; Barton, Chris D.Overall results and key findings on the use of UAV visible-color, multispectral, and thermal infrared imagery to map agricultural drainage pipes
Effective and efficient methods are needed to map agricultural subsurface drainage systems. Visible-color (VIS-C), multispectral (MS), and thermal infrared (TIR) imagery obtained by unmanned aerial vehicles (UAVs) may provide a means for determining drainage pipe locations. Aerial surveys using a UAV with VIS-C, MS, and TIR cameras were conducted...
Allred, Barry J.; Martinez, Luis; Fessehazion, Melake; Rouse, Greg; Williamson, Tanja N.; Wishart, DeBonne; Koganti, Triven; Freeland, Robert; Eash, Neal; Batschelet, Adam; Featheringill, RobertTracking phosphorus and sediment sources and transport from fields and channels in Great Lakes Restoration Initiative priority watersheds
A multi-agency, integrated series of studies were initiated in 2017 under the Great Lakes Restoration Initiative (GLRI) by the U.S. Geological Survey, U.S. Forest Service, and the University of Minnesota to quantify the source, downstream travel time, and storage of particulate-bound phosphorus and sediment in agricultural tributaries to the Great...
Williamson, Tanja N.; Fitzpatrick, Faith A.; Karwan, Diana L.; Kolka, Randall K.; Dobrowolski, Edward G.; Blount, James; Pawlowski, Ethan D.Reduced soil macropores and forest cover reduce warm-season baseflow below ecological thresholds in the upper Delaware River Basin
We examined the impacts of changes in land cover and soil conditions on the flow regime of the upper Delaware River Basin using the Water Availability Tool for Environmental Resources (WATER). We simulated flows for two periods, circa 1600 and 1940, at three sites using the same temperature and precipitation conditions: the East Branch (EB), West...
Endreny, Theodore A.; Kwon, Peter Yong Seuk; Williamson, Tanja N.; Evans, RichardDelineation of tile-drain networks using thermal and multispectral imagery—Implications for water quantity and quality differences from paired edge-of-field sites
As part of the Great Lakes Restoration Initiative, paired edge-of-field sites were established in high priority subwatersheds to assess the effectiveness of agricultural management practices. One pairing was in Black Creek, a tributary to the Maumee River and Lake Erie. These fields were paired because of similarity in soils, topography, and...
Williamson, Tanja N.; Dobrowolski, Edward G.; Meyer, Shawn M.; Frey, Jeffrey W.; Allred, Barry J.Sensitivity of streamflow simulation in the Delaware River Basin to forecasted land‐cover change for 2030 and 2060
In order to simulate the potential effect of forecasted land‐cover change on streamflow and water availability, there has to be confidence that the hydrologic model used is sensitive to small changes in land cover (<10%) and that this land‐cover change exceeds the inherent uncertainty in forecasted conditions. To investigate this, a 26‐year...
Williamson, Tanja N.; Claggett, Peter R.Multiple-source tracking: Investigating sources of pathogens, nutrients, and sediment in the Upper Little River Basin, Kentucky, water years 2013–14
The South Fork Little River (SFLR) and the North Fork Little River (NFLR) are two major headwater tributaries that flow into the Little River just south of Hopkinsville, Kentucky. Both tributaries are included in those water bodies in Kentucky and across the Nation that have been reported with declining water quality. Each tributary has been...
Crain, Angela S.; Cherry, Mac A.; Williamson, Tanja N.; Bunch, Aubrey R.Water quality and natural resources in the Green River Basin
No abstract available.
Lee, Brad D.; Williamson, Tanja N.; Crain, Angela S.Sensitivity of the projected hydroclimatic environment of the Delaware River basin to formulation of potential evapotranspiration
The Delaware River Basin (DRB) encompasses approximately 0.4 % of the area of the United States (U.S.), but supplies water to 5 % of the population. We studied three forested tributaries to quantify the potential climate-driven change in hydrologic budget for two 25-year time periods centered on 2030 and 2060, focusing on sensitivity to...
Williamson, Tanja N.; Nystrom, Elizabeth A.; Milly, Paul C.D.Classification of ephemeral, intermittent, and perennial stream reaches using a TOPMODEL-based approach
Whether a waterway is temporary or permanent influences regulatory protection guidelines, however, classification can be subjective due to a combination of factors, including time of year, antecedent moisture conditions, and previous experience of the field investigator. Our objective was to develop a standardized protocol using publicly ...
Williamson, Tanja N.; Agouridis, Carmen T.; Barton, Christopher D.; Villines, Jonathan A.; Lant, Jeremiah G.Summary of hydrologic modeling for the Delaware River Basin using the Water Availability Tool for Environmental Resources (WATER)
The Water Availability Tool for Environmental Resources (WATER) is a decision support system for the nontidal part of the Delaware River Basin that provides a consistent and objective method of simulating streamflow under historical, forecasted, and managed conditions. In order to quantify the uncertainty associated with these simulations, however...
Williamson, Tanja N.; Lant, Jeremiah G.; Claggett, Peter R.; Nystrom, Elizabeth A.; Milly, Paul C.D.; Nelson, Hugh L.; Hoffman, Scott A.; Colarullo, Susan J.; Fischer, Jeffrey M.