Publications

The Sacramento-San Joaquin Delta is the largest delta on the west coast of the United States. It is formed where the confluence of California’s two largest rivers (the Sacramento and San Joaquin) meet the ocean tides and has a significant physical gradient from fluvial to tidal. It is a semidiurnal system (two high and two low tides per day). Today, the Delta is one of the most...

The ability of biogeochemical ecosystem models to represent agro-ecosystems depends on their correct integration with field observations. We report simultaneous calibration of 67 DayCent model parameters using multiple observation types through inverse modeling using the PEST parameter estimation software. Parameter estimation reduced the total sum of weighted squared residuals by 56%...

Sediment fingerprinting quantifies the delivery of fine-grained sediment from a watershed and sediment-budget measurements quantify the erosion and deposition of fine-grained sediment. Both approaches were used in the agricultural and forested 147-square-kilometer (km2) Linganore Creek watershed in Maryland from August 1, 2008 through December 31, 2010, to determine the sources of fine...

The potential for increases in stream temperature across many spatial and temporal scales as a result of climate change can pose a difficult challenge for environmental managers, especially when addressing thermal requirements for sensitive aquatic species. This study evaluates simulated changes to the thermal regime of three northern Wisconsin streams in response to a projected changing...

In synoptic surveys of surface-water quality across the United States, a large group of organic chemicals associated with agricultural, household, and industrial waste have been detected. These chemicals are referred to collectively as chemicals of emerging concern (CECs) and include prescription drugs and antibiotics, over-the-counter medications, reproductive hormones, personal-care...

Newly produced, as well as some so-called legacy contaminants, continue to be released into the environment at an accelerated rate. Given the general lack of integrated, direct monitoring programs, the use of natural archival records of contaminants will almost certainly continue to increase. We conclude this volume with a short chapter highlighting some of our final thoughts, with a...

This book explores the myriad ways that environmental archives can be used to study the distribution and long-term trajectories of contaminants. The volume first focuses on reviews that examine the integrity of the historic record, including factors related to hydrology, post-depositional diffusion, and mixing processes. This is followed by a series of chapters dealing with the diverse...

The way water flows to a lake, through streams, as runoff, or as groundwater, can control the distribution and mass of sediment and contaminants deposited. Whether a lake is large or small, deep or shallow, open or closed, the movement of water to a lake and the circulation patterns of water within a lake control how and where sediment and contaminants are deposited. Particle-associated

The U.S. Geological Survey (USGS) South Atlantic Water Science Center (SAWSC) Georgia office, in cooperation with local, State, and other Federal agencies, maintains a long-term hydrologic monitoring network of more than 340 real-time continuous-record streamflow-gaging stations (streamgages), including 10 real-time lake-level monitoring stations, 67 real-time surface-water-quality...

Over timescales of soil development (millennia), the capacity of soils to stabilize soil organic carbon (SOC) is linked to soil development through changes in soil mineralogy and other soil properties. In this study, an extensive dataset of soil profile chemistry and mineralogy is compiled from the Cowlitz River Chronosequence (CRC), WA USA. The CRC soils range in age from 0.25 to 1200...

Sediment is recognized as a major environmental sink for contaminants, including engineered nanoparticles (NPs). Consequently, sediment-living organisms are likely to be exposed to NPs. There is evidence that both accumulation and toxicity of metal NPs to sediment-dwellers increase with decreasing particle size, although NP size does not always predict effects. In contrast, not much is...

The maps and graphs in this summary describe streamflow conditions for water year 2014 (October 1, 2013, to September 30, 2014) in the context of the 85-year period from 1930 through 2014, unless otherwise noted. The illustrations are based on observed data from the U.S. Geological Survey’s (USGS) National Streamflow Information Program (NSIP) (http://water.usgs.gov/nsip/). The period...