Treesearch

Estuarine condition is a function of the nature of the estuary, ocean, and atmospheric systems, and the upstream watershed. To fully understand and predict how an estuary will respond to drivers and pressures, each compartment must be characterized. For example, eutrophication effects on estuarine condition are generally well known; less understood is how the attributes of estuarine watersheds, and their spatial distributions, relate to estuarine condition.

The potential impact of climate change on wetland-provided ecosystem services has been largely unspecified because of the difficulty in predicting changing hydrologic conditions, which are a major driver of structure and function in these ecosystems. The Penn State Integrated Hydrologic Model (PIHM), constructed and calibrated using nationally available data sets (e.g., soils, topography, national wetlands inventory (NWI) wetlands, USGS stream gages), was used to generate groundwater depth conditions for multiple hydrogeomorphic (HGM) wetland types (depression, slope, riverine), across a...

Future changes in climatic conditions may affect variations in watershed processes (e.g., hydrological, biogeochemical) and surface water quality across a wide range of physiographic provinces, ecosystems, and spatial scales. How such climatic shifts will impact watershed mercury (Hg) dynamics and hydrologically-driven Hg transport is a significant concern.

Excessive sediment and nutrient loading are among the leading causes of impairment in water bodies of the United States due to their effect on biologic productivity, water quality, and aquatic food webs. Understanding the nutrient and suspended sediment loads affecting estuarine waters is fundamental to the assessment of the physical, chemical, and biological processes governing the aquatic system and essential for establishing watershed management strategies.

Closing watershed nitrogen budgets is difficult because inputs typically far exceed outputs. A leading hypothesis to explain this discrepancy is that retention is poorly constrained because a disproportionate amount of denitrification occurs in small portions of the landscape (hot spots) during brief hydrologic conditions (hot moments).

High frequency in situ nitrate data from three streams of varying hydrologic condition, land use, and watershed size were used to quantify the mass loading of nitrate to streams from two sources – groundwater discharge and event flow – at a daily time step for one year. These estimated loadings were used to quantify temporally-variable in-stream nitrate processing rates.

Dissolved organic matter (DOM) is recognized as a major component in the global carbon cycle and is an important driver of numerous biogeochemical processes in aquatic ecosystems, both in-stream and downstream in estuaries. This study sought to characterize chromophoric DOM (CDOM), dissolved organic carbon (DOC), and dissolved nutrients in major rivers and their tributaries of the South Carolina Coastal Plain to assess the impact of land cover,soils, and other factors on water quality.

Long-term land-use and land cover change and their associated impacts pose critical challenges to sustaining vital hydrological ecosystem services for future generations. In this study, a methodology was developed to characterize potential hydrologic impacts from future urban growth through time. Future growth is represented by housing density maps generated in decadal intervals from 2010 to 2100, produced by the U.S. Environmental Protection Agency (EPA) Integrated Climate and Land-Use Scenarios (ICLUS) database. ICLUS developed future housing density maps by adapting the Intergovernmental...

The goal of this project was to investigate the relationship between the shallow, unconfined aquifer and woody vegetation at eight sites of the Congaree Observation Well Network at Congaree National Park near Hopkins, South Carolina. Eight piezometers with screens of 1.5-m length (top-of-screen depths ranging from 3.0 to 5.0 m below ground surface) along a 1.8-km cross-valley transect from the foot of a fluvial terrace and terminating near Cedar Creek in the national park.

In the southern Appalachians USA, the boundaries of riparian areas are often hard to define. Vegetation is often used as a riparian indicator and plays a key role in protecting water resources, but adequate knowledge of floristic responses to riparian disturbances is lacking. Our objective was to quantify floristic composition and diversity of the riparian communities before (2004) and one, two, and seven years after harvest treatments with varying buffer widths. The treatments were harvest distances of 0 m, 10 m, and 30 m away from the stream edge. Sites were harvested between 2005 and 2006.