Publications

Hydrologic and biologic data collected from October 1996 through September 1998 in the Eastern Iowa Basins study unit of the U.S. Geological Survey National Water-Quality Assessment Program are presented in this report. Monthly data collected from 12 sites on rivers and streams included measurements of physical properties and determinations of the concentrations of nutrients, major ions...

Ground-water conditions in Georgia during 1999 and for the period of record were evaluated using data from U.S. Geological Survey ground-water-level and ground-water-quality monitoring networks. Data for 1999 included in this report are from continuous water-level records from 130 wells and chloride analyses from 14 wells. Data from one well is incomplete because data collection was...

Two methods were used to convey the spatial association between a classified forested landscape, the distribution of a hurricane impact, and the subsequent recovery of the habitat from the storm. The first method used a constant hue matrix with varying intensity to visually represent combinations of impact and recovery magnitudes. The second combined two colors of constant hue to...

Overview The U.S. Geological Survey is participating in a multi-institutional effort to assess, monitor, and restore the ecosystem of South Florida. Federal, State and local agencies are collaborating to establish a firm scientific basis for land management and water policy issues. Historical changes in South Florida related to rapid population growth in the early to middle 1900's have...

The Rio GrandefRio Bravo drains an area of more than 440,300 square kilometers of Mexico and southwestern United States (Bartlett. 1984). The Rio Grande flows for 3,000 kilometers from its headwaters in the San Juan Mountains of southern Colorado to the Gulf of Mexico downstream of Brownsville, Texas. The "Rio," as it is often called, drains the southern Rocky Mountains of Colorado and...

In January 1999, the U.S. Geological Survey collected estuarine-water, estuarine-sediment, surface-water, and ground-water quality samples in the vicinity of Naval Submarine Base Kings Bay, Camden County, Georgia. Data from these samples are used by the U.S. Navy to monitor the impact of submarine base activities on local water resources. Estuarine water and sediment data were collected...

As society has come to equate economic prosperity with the health of our living resources, national science policy has called for the development of a comprehensive digital knowledge base to support informed decision making and wise resource management. The Internet and World Wide Web demonstrate the earliest stages of this evolving virtual library of the natural world, offering an...

In May 1998, the U.S. Geological Survey, in cooperation with the Environmental and Natural Resources Management Office of the U.S. Army Signal Center and Fort Gordon, investigated the presence and disbursal of trace elements and semi-volatile organic compounds in bed sediments from selected streams and impoundments at the Fort Gordon military installation near Augusta, Georgia...

Using multiple-proxy biological indicators, a paleoecological history of the past 550 years of Featherbed Bank, Biscayne Bay, has been reconstructed from a short (2.26 m) sediment core. Paleoecological changes in ostracode, mollusc, and foraminifer assemblages show that core SEI297-FB-1 can be divided into three distinctly different zones, which together provide evidence for distinct...

In the past decade seagrass die-offs, algal blooms, and declining numbers of shellfish and sponges have occurred in Florida Bay. These changes have been attributed to human activities; however, neither the natural patterns of change, nor the pre-human baseline for the environment have been determined. Currently, efforts are underway to restore the Everglades ecosystem to a more natural...

The U.S. Geological Survey (USGS) is working closely with other Federal and State agencies in a comprehensive program to evaluate and restore the south Florida ecosystem. Within the USGS South Florida Ecosystem Program, a project entitled 'Coupling Models for Canal and Wetland Flow/Transport Interaction' is focused on analysis and numerical simulation of flow and potential transport of

Changes in water-management practices have been made to accommodate a large and rapidly growing urban population along the Atlantic Coast and to meet the demand for intensive agricultural activities. These changes have resulted in a highly managed hydrologic system consisting of numerous canals, levees, control structures, and pumping stations that have altered the hydrology of the...