High-Resolution Soil Moisture Prediction and Validation in Forested Watersheds across the United States

The U.S. Forest Service–led Forest Soil Moisture Monitoring Network (FSMMN) is sponsoring a series of pilot studies to improve soil moisture monitoring and predictions in forests and rangelands. These studies are intended to address both broad and forest-specific limitations in current monitoring methodologies for high-relief and forested topographies, and to develop improved monitoring and assessment tools. 

A series of pilot studies are being conducted in partnership with the USDA Natural Resources Conservation Service (NRCS) as part of the NRCS Dynamic Soil Survey. Initial projects include software development for data cleaning and quality assurance, testing spatially explicit models of soil moisture dynamics at watershed scales using new and historical data, and linking forest disturbances to soil moisture conditions to inform forest-specific needs and resources. Established sites include forests across North Carolina, West Virginia, New Hampshire, and Arizona, with new sites being added in Minnesota and Alaska. These sites have long streamflow records and are also Long-Term Ecological Research sites, so they have a wealth of additional long-term climatic and ecological data available for validating results. 

One recent project focused on testing the Regional Hydro-Ecological Simulation System (RHESSys) model, a hydro-ecological model designed to simulate integrated water, carbon, and nutrient cycling and transport over spatially variable terrain. The research explored the sensitivity in the spatial and temporal dynamics of soil moisture to different model parameterizations, including incorporating NRCS soil survey data (SSURGO) and newly developed NRCS Digital Soil Mapping products. Additional projects are underway to further investigate hydrologic modeling of soil moisture at Hubbard Brook Experimental Forest, Fernow Experimental Forest, and Marcell Experimental Forest using new data generated by the FSMMN and in collaboration with university partners. 

These efforts are intended to inform forest-based soil data collection efforts and, ultimately, improve the information available when setting guidelines for forest and range management actions. Areas of interest include soil erosion, trafficability, pollutant transport and attenuation, and disturbance response. 

For more information, please contact Stephanie Connolly (stephanie.connolly@usda.gov).