2011 Research Highlights
Understanding Soil and Watershed Hydrology
Filling a knowledge gap regarding impacts of soil characteristics on stream discharge
Forests in North Carolina cover 60 percent of the land surface equaling about 18 million acres. Understanding the impact of soil properties on forest hydrology and water quality can offer valuable information to researchers and water resource managers in addressing water shortages during droughts. For example, watershed specific baseflow, stormflow, and water quality patterns can be used to further assess issues such as reservoir release requirements, land acquisition strategies, project management options, and nutrient divergence from background values due to tree stem removal, land development, and other disturbances. EFETAC scientists examined forest hydrology and water quality patterns in North Carolina piedmont headwater watersheds with different geologic features and soil characteristics, Carolina Slate Belt (CSB) and Triassic Basin (TB), and offered reference or baseline data for area watershed planning.
Significant differences exist between CSB and TB annual streamflow with TB watersheds generating about 30 percent more annual runoff. TB streams generally had higher annual nutrient and sediment exports compared to CSB streams. A weak relationship was found between nutrient concentrations and discharge suggesting that biogeochemistry is a controlling factor in nutrient inputs and concentrations in both CSB and TB streams. It appears that soils in the two geologic areas influenced hydrologic processes such as stormflow generation and soil water storage dynamics and to a lesser extent water quality conditions.
Contact: Johnny Boggs, biological scientist, johnny.boggs@usda.gov
