Improved daily precipitation nitrate and ammonium concentration models for the Chesapeake Bay Watershed.

Science.gov (United States)

Grimm, J W; Lynch, J A

2005-06-01

Daily precipitation nitrate and ammonium concentration models were developed for the Chesapeake Bay Watershed (USA) using a linear least-squares regression approach and precipitation chemistry data from 29 National Atmospheric Deposition Program/National Trends Network (NADP/NTN) sites. Only weekly samples that comprised a single precipitation event were used in model development. The most significant variables in both ammonium and nitrate models included: precipitation volume, the number of days since the last event, a measure of seasonality, latitude, and the proportion of land within 8km covered by forest or devoted to industry and transportation. Additional variables included in the nitrate model were the proportion of land within 0.8km covered by water and/or forest. Local and regional ammonia and nitrogen oxide emissions were not as well correlated as land cover. Modeled concentrations compared very well with event chemistry data collected at six NADP/AirMoN sites within the Chesapeake Bay Watershed. Wet deposition estimates were also consistent with observed deposition at selected sites. Accurately describing the spatial distribution of precipitation volume throughout the watershed is important in providing critical estimates of wet-fall deposition of ammonium and nitrate.

Eliciting stakeholder values for coral reef management tasks in the Guánica Bay watershed, Puerto Rico

Science.gov (United States)

The EPA is developing a valuation protocol for southwest Puerto Rico that will support the US Coral Reef Task Force’s (USCRTF) Partnership Initiative in the Guánica Bay/Rio Loco (GB/RL) Watershed. The GB/RL watershed is located in southwestern Puerto Rico and includes the urbaniz...

Assessments of urban growth in the Tampa Bay watershed using remote sensing data

Science.gov (United States)

Xian, G.; Crane, M.

2005-01-01

Urban development has expanded rapidly in the Tampa Bay area of west-central Florida over the past century. A major effect associated with this population trend is transformation of the landscape from natural cover types to increasingly impervious urban land. This research utilizes an innovative approach for mapping urban extent and its changes through determining impervious surfaces from Landsat satellite remote sensing data. By 2002, areas with subpixel impervious surface greater than 10% accounted for approximately 1800 km2, or 27 percent of the total watershed area. The impervious surface area increases approximately three-fold from 1991 to 2002. The resulting imperviousness data are used with a defined suite of geospatial data sets to simulate historical urban development and predict future urban and suburban extent, density, and growth patterns using SLEUTH model. Also examined is the increasingly important influence that urbanization and its associated imperviousness extent have on the individual drainage basins of the Tampa Bay watershed.

Distribution characteristics of volatile methylsiloxanes in Tokyo Bay watershed in Japan: Analysis of surface waters by purge and trap method.

Science.gov (United States)

Horii, Yuichi; Minomo, Kotaro; Ohtsuka, Nobutoshi; Motegi, Mamoru; Nojiri, Kiyoshi; Kannan, Kurunthachalam

2017-05-15

Surface waters including river water and effluent from sewage treatment plants (STPs) were collected from Tokyo Bay watershed, Japan, and analyzed for seven cyclic and linear volatile methylsiloxanes (VMSs), i.e., D3, D4, D5, D6, L3, L4, and L5 by an optimized purge and trap extraction method. The total concentrations of seven VMSs (ΣVMS) in river water ranged from watershed was estimated at 2300kg. Our results indicate widespread distribution of VMSs in Tokyo Bay watershed and the influence of domestic wastewater discharges as a source of VMSs in the aquatic environment. Copyright © 2017 Elsevier B.V. All rights reserved.

Trends in Surface-Water Nitrate-N Concentrations and Loads from Predominantly-Forested Watersheds of the Chesapeake Bay Basin

Science.gov (United States)

Eshleman, K. N.

2011-12-01

Water quality monitoring data from streams and rivers provide the "gold standard" by which progress toward achieving real reductions in nutrient loadings to Chesapeake Bay must ultimately be assessed. The most recent trend results posted at the Chesapeake Bay Program (CBP) website reveal that a substantial percentage of tributaries are now showing long-term declines in flow-adjusted concentrations of nutrients and sediments: 22 sites showed statistically significant (p pollution controls for improved wastewater treatment plants and practices to reduce nutrients on farms and suburban lands, have reduced concentrations of nitrogen." But could this conclusion be pre-mature? I recently undertook a comparable analysis of long-term nitrate-N trends for a different group of watersheds (all located in the Chesapeake Bay watershed with long data records); this group includes nine watersheds that are predominantly (i.e., >75%) forested, plus five other Potomac River subwatersheds added for comparison. Based on comparable data and analytical methods to those used by CBP partners and USGS, 13 of the 14 sites-including both Potomac River stations (Chain Bridge at Washington DC and Hancock, Maryland)-showed statistically significant decreasing linear trends in annual flow-weighted nitrate-N concentration. Only one station-the heavily agricultural Upper Monocacy River-did not show a statistically significant (p RIM station could be entirely explained by commensurate improvements at the upstream (Hancock) station; in fact, no trend in nitrate-N concentration associated with the eastern portion of the basin was found (after subtracting out the influence of the upstream portion). Additional research is needed to understand why nitrogen retention by forested lands may be increasing and thus helping restore water quality throughout the Chesapeake Bay watershed. The results also have obvious implications for meeting local water quality goals as well as the basin-wide goal of the

Impact of Environmental Policies on the Adoption of Animal Waste Management Practices in the Chesapeake Bay Watershed

OpenAIRE

Savage, Jeff; Ribaudo, Marc

2012-01-01

We use data from the ERS-NASS ARMS surveys to compare the use of best management practices on poultry and livestock farms inside the watershed and outside the watershed. Animal operations within the Chesapeake Bay States were found to be adopting some important manure management practices at a greater rate than operations outside the watershed. Adoption was taking place before the implementation of the TMDL, indicating that farmers may have been acting in response to building public pressure ...

75 FR 27552 - Guidance for Federal Land Management in the Chesapeake Bay Watershed

Science.gov (United States)

2010-05-17

... will allow the federal government to lead the way in protecting the Bay and its watershed with the most effective tools and practices available to reduce water pollution from a variety of nonpoint sources... describe ``proven cost-effective tools and practices that reduce water pollution'' that are appropriate to...

Understanding Urban Watersheds through Digital Interactive Maps, San Francisco Bay Area, California

Science.gov (United States)

Sowers, J. M.; Ticci, M. G.; Mulvey, P.

2014-12-01

Dense urbanization has resulted in the "disappearance" of many local creeks in urbanized areas surrounding the San Francisco Bay. Long reaches of creeks now flow in underground pipes. Municipalities and water agencies trying to reduce non-point-source pollution are faced with a public that cannot see and therefore does not understand the interconnected nature of the drainage system or its ultimate discharge to the bay. Since 1993, we have collaborated with the Oakland Museum, the San Francisco Estuary Institute, public agencies, and municipalities to create creek and watershed maps to address the need for public understanding of watershed concepts. Fifteen paper maps are now published (www.museumca.org/creeks), which have become a standard reference for educators and anyone working on local creek-related issues. We now present digital interactive creek and watershed maps in Google Earth. Four maps are completed covering urbanized areas of Santa Clara and Alameda Counties. The maps provide a 3D visualization of the watersheds, with cartography draped over the landscape in transparent colors. Each mapped area includes both Present and Past (circa 1800s) layers which can be clicked on or off by the user. The Present layers include the modern drainage network, watershed boundaries, and reservoirs. The Past layers include the 1800s-era creek systems, tidal marshes, lagoons, and other habitats. All data are developed in ArcGIS software and converted to Google Earth format. To ensure the maps are interesting and engaging, clickable icons pop-up provide information on places to visit, restoration projects, history, plants, and animals. Maps of Santa Clara Valley are available at http://www.valleywater.org/WOW.aspx. Maps of western Alameda County will soon be available at http://acfloodcontrol.org/. Digital interactive maps provide several advantages over paper maps. They are seamless within each map area, and the user can zoom in or out, and tilt, and fly over to explore

Late Holocene Environmental History of the Los Osos Watershed, Morro Bay, CA

Science.gov (United States)

Broadman, E.; Reidy, L. M.; Wahl, D.

2014-12-01

A comprehensive understanding of past changes in wetland ecosystems is integral for creating policies for modern land use practices. The Morro Bay salt marsh is home to a large wetland that has experienced significant environmental impacts in the last few centuries. In this study, sediment cores from the Morro Bay salt marsh were analyzed to discern changes in environment since the time of European contact, which occurred in 1772. The marsh is fed by two creeks (Chorro and Los Osos) and their associated watersheds. Sediment cores taken from a portion of the marsh fed by Los Osos creek were analyzed and the results compared to those from previous studies on cores taken from the Chorro and Los Osos portions of the marsh. Magnetic susceptibility, loss on ignition, pollen, radiocarbon, and X-ray fluorescence (XRF) analyses were conducted. An age-depth model was established for the Los Osos cores using two radiocarbon dates, as well as Erodium cicutarium as a chronological marker. Preliminary pollen analysis from Chorro marsh cores indicates vegetation shifts at the time of contact, when the salt marsh formed. Magnetic susceptibility and XRF data indicate dramatically increased rates of erosion from the time of contact consistently until the present. Influx of non-carbonate inorganic material also indicates a rapid increase in sedimentation in the marsh starting at the time of contact. Comparison of sedimentation rates between the two creeks suggests that differences in watershed geomorphology and land use practices have had pronounced impacts on erosional processes. Over the last decade, the Morro Bay National Estuary Program (MBNEP) has taken more measures to reduce erosion and sedimentation rates in the Chorro watershed, as is reflected by reduced sedimentation rates in MBNEP data collected within the last few years. Our study helps to elucidate the impacts of anthropogenic land use change on wetland systems, and provides much needed data to policy makers seeking to

Sources of suspended-sediment flux in streams of the chesapeake bay watershed: A regional application of the sparrow model

Science.gov (United States)

Brakebill, J.W.; Ator, S.W.; Schwarz, G.E.

2010-01-01

We describe the sources and transport of fluvial suspended sediment in nontidal streams of the Chesapeake Bay watershed and vicinity. We applied SPAtially Referenced Regressions on Watershed attributes, which spatially correlates estimated mean annual flux of suspended sediment in nontidal streams with sources of suspended sediment and transport factors. According to our model, urban development generates on average the greatest amount of suspended sediment per unit area (3,928 Mg/km2/year), although agriculture is much more widespread and is the greatest overall source of suspended sediment (57 Mg/km2/year). Factors affecting sediment transport from uplands to streams include mean basin slope, reservoirs, physiography, and soil permeability. On average, 59% of upland suspended sediment generated is temporarily stored along large rivers draining the Coastal Plain or in reservoirs throughout the watershed. Applying erosion and sediment controls from agriculture and urban development in areas of the northern Piedmont close to the upper Bay, where the combined effects of watershed characteristics on sediment transport have the greatest influence may be most helpful in mitigating sedimentation in the bay and its tributaries. Stream restoration efforts addressing floodplain and bank stabilization and incision may be more effective in smaller, headwater streams outside of the Coastal Plain. ?? 2010 American Water Resources Association. No claim to original U.S. government works.

Land Use and Climate Alter Carbon Dynamics in Watersheds of Chesapeake Bay

Science.gov (United States)

Kaushal, S.; Duan, S.; Grese, M.; Pennino, M. J.; Belt, K. T.; Findlay, S.; Groffman, P. M.; Mayer, P. M.; Murthy, S.; Blomquist, J.

2011-12-01

There have been long-term changes in the quantity of organic carbon in streams and rivers globally. Shifts in the quality of organic carbon due to environmental changes may also impact downstream ecosystem metabolism and fate and transport of contaminants. We investigated long-term impacts of land use and hydrologic variability on organic carbon transport in watersheds of the Baltimore Long-Term Ecological Research (LTER) site and large rivers of the Chesapeake Bay. In small and medium-sized watersheds of the Baltimore LTER site, urban land use increased organic carbon concentrations in streams several-fold compared to forest and agricultural watersheds. Enzymatic activities of stream microbes were significantly altered across watershed land use during a record wet year. During the wet year, short-term bioassays showed that bioavailable dissolved organic carbon varied seasonally, but comprised a substantial proportion of the dissolved organic carbon pool. Similarly, measurements of biochemical oxygen demand across hydrologic variability suggest that reactive organic carbon export from small and medium-sized urban watersheds during storms can be substantial. At a larger regional scale, major tributaries such as the Potomac, Susquehanna, Patuxent, and Choptank rivers also showed similar variability as smaller watersheds in quantity and quality of organic carbon based on land use and climate. There were distinct isotopic values of d13C of particulate organic matter and fluorescence excitation emission matrices for rivers influenced by different land uses. Stable isotopic values of d13C of particulate organic matter and fluorescence excitation emission matrices showed marked seasonal changes in organic matter quality during spring floods in the Potomac River at Washington D.C. Across watershed size, there appeared to be differences in seasonal cycles of organic carbon quality and this may have been based on the degree of hydrologic connectivity between watersheds and

Linking ecosystem service supply to stakeholder concerns on both land and sea: An example from Guánica Bay watershed, Puerto Rico

Science.gov (United States)

Policies to protect coastal resources may lead to greater social, economic, and ecological returns when they consider potential co-benefits and trade-offs on land. In Guánica Bay watershed, Puerto Rico, a watershed management plan is being implemented to restore declining quality...

Robust Decision Making to Support Water Quality Climate Adaptation: a Case Study in the Chesapeake Bay Watershed

Science.gov (United States)

Fischbach, J. R.; Lempert, R. J.; Molina-Perez, E.

2017-12-01

The U.S. Environmental Protection Agency (USEPA), together with state and local partners, develops watershed implementation plans designed to meet water quality standards. Climate uncertainty, along with uncertainty about future land use changes or the performance of water quality best management practices (BMPs), may make it difficult for these implementation plans to meet water quality goals. In this effort, we explored how decision making under deep uncertainty (DMDU) methods such as Robust Decision Making (RDM) could help USEPA and its partners develop implementation plans that are more robust to future uncertainty. The study focuses on one part of the Chesapeake Bay watershed, the Patuxent River, which is 2,479 sq km in area, highly urbanized, and has a rapidly growing population. We simulated the contribution of stormwater contaminants from the Patuxent to the overall Total Maximum Daily Load (TMDL) for the Chesapeake Bay under multiple scenarios reflecting climate and other uncertainties. Contaminants considered included nitrogen, phosphorus, and sediment loads. The assessment included a large set of scenario simulations using the USEPA Chesapeake Bay Program's Phase V watershed model. Uncertainties represented in the analysis included 18 downscaled climate projections (based on 6 general circulation models and 3 emissions pathways), 12 land use scenarios with different population projections and development patterns, and alternative assumptions about BMP performance standards and efficiencies associated with different suites of stormwater BMPs. Finally, we developed cost estimates for each of the performance standards and compared cost to TMDL performance as a key tradeoff for future water quality management decisions. In this talk, we describe how this research can help inform climate-related decision support at USEPA's Chesapeake Bay Program, and more generally how RDM and other DMDU methods can support improved water quality management under climate

Invasive Species Guidebook for Department of Defense Installations in the Chesapeake Bay Watershed: Identification, Control, and Restoration

Science.gov (United States)

2007-11-01

Crown vetch Coronilla varia MD, VA 14 Leafy spurge Euphorbia esula VA 15 Ground ivy Glechoma hederacea DC, MD, PA, VA, WV 17 Cogongrass Imperata ...INSTALLATIONS IN THE CHESAPEAKE BAY WATERSHED IDENTIFICATION AND CONTROL METHODS Cogongrass ( Imperata cylindrica) Description & Biology – A large

Magnitude and frequency of flooding on small urban watersheds in the Tampa Bay area, west-central Florida

Science.gov (United States)

Lopez, M.A.; Woodham, W.M.

1983-01-01

Hydrologic data collected on nine small urban watersheds in the Tampa Bay area of west-central Florida and a method for estimating peak discharges in the study area are described. The watersheds have mixed land use and range in size from 0.34 to 3.45 square miles. Watershed soils, land use, and storm-drainage system data are described. Urban development ranged from a sparsely populated area with open-ditch storm sewers and 19% impervious area to a completely sewered watershed with 61% impervious cover. The U.S. Geological Survey natural-basin and urban-watershed models were calibrated for the nine watersheds using 5-minute interval rainfall data from the Tampa, Florida, National Weather Service rain gage to simulate annual peak discharge for the period 1906-52. A log-Pearson Type III frequency analysis of the simulated annual maximum discharge was used to determine the 2-, 5-, 10-, 25-, 50-, and 100-year flood discharges for each watershed. Flood discharges were related in a multiple-linear regression to drainage area, channel slope, detention storage area, and an urban-development factor determined by the extent of curb and gutter street drainage and storm-sewer system. The average standard error for the regional relations ranged from + or - 32 to + or - 42%. (USGS)

Chesapeake Bay recovery and factors affecting trends: Long-termmonitoring, indicators, and insights

Science.gov (United States)

Tango, Peter J.; Batiuk, Richard A.

2016-01-01

Monitoring the outcome of restoration efforts is the only way to identify the status of a recovery and the most effective management strategies. In this paper, we discuss Chesapeake Bay and watershed recovery and factors influencing water quality trends. For over 30 years, the Chesapeake Bay Program Partnership’s long-term tidal and watershed water quality monitoring networks have measured physical, chemical and biological parameters throughout the bay and its surrounding watershed underpinning an adaptive management process to drive ecosystem recovery. There are many natural and anthropogenic factors operating and interacting to affect the watershed and bay water quality recovery responses to management actions. Across habitats and indicators, the bay and its watershed continue to express a diverse spatial and temporal fabric of multiscale conditions, stressors and trends that show a range of health conditions and impairments, as well as evidence of progress and degradation. Recurrent independent reviews of the monitoring program have driven a culture of continued adaptation of the monitoring networks to reflect ever evolving management information needs. The adherence to bay and watershed-wide consistent monitoring protocols provides monitoring data supporting analyses and development of scientific syntheses that underpin indicator and model development, regulatory assessments, targeting of management actions, evaluation of management effectiveness, and directing of priorities and policies.

Watershed and Hydrodynamic Modeling for Evaluating the Impact of Land Use Change on Submerged Aquatic Vegetation and Seagrasses in Mobile Bay

Science.gov (United States)

Estes, Maurice G.; Al-Hamdan, Mohammed; Thom, Ron; Quattrochi, Dale; Woodruff, Dana; Judd, Chaeli; Ellism Jean; Watson, Brian; Rodriguez, Hugo; Johnson, Hoyt

2009-01-01

There is a continued need to understand how human activities along the northern Gulf of Mexico coast are impacting the natural ecosystems. The gulf coast is experiencing rapid population growth and associated land cover/land use change. Mobile Bay, AL is a designated pilot region of the Gulf of Mexico Alliance (GOMA) and is the focus area of many current NASA and NOAA studies, for example. This is a critical region, both ecologically and economically to the entire United States because it has the fourth largest freshwater inflow in the continental USA, is a vital nursery habitat for commercially and recreational important fisheries, and houses a working waterfront and port that is expanding. Watershed and hydrodynamic modeling has been performed for Mobile Bay to evaluate the impact of land use change in Mobile and Baldwin counties on the aquatic ecosystem. Watershed modeling using the Loading Simulation Package in C++ (LSPC) was performed for all watersheds contiguous to Mobile Bay for land use Scenarios in 1948, 1992, 2001, and 2030. The Prescott Spatial Growth Model was used to project the 2030 land use scenario based on observed trends. All land use scenarios were developed to a common land classification system developed by merging the 1992 and 2001 National Land Cover Data (NLCD). The LSPC model output provides changes in flow, temperature, sediments and general water quality for 22 discharge points into the Bay. These results were inputted in the Environmental Fluid Dynamics Computer Code (EFDC) hydrodynamic model to generate data on changes in temperature, salinity, and sediment concentrations on a grid with four vertical profiles throughout the Bay s aquatic ecosystems. The models were calibrated using in-situ data collected at sampling stations in and around Mobile bay. This phase of the project has focused on sediment modeling because of its significant influence on light attenuation which is a critical factor in the health of submerged aquatic

Residence times and nitrate transport in ground water discharging to streams in the Chesapeake Bay Watershed

Science.gov (United States)

Lindsey, Bruce D.; Phillips, Scott; Donnelly, Colleen A.; Speiran, Gary K.; Plummer, Niel; Bohlke, John Karl; Focazio, Michael J.; Burton, William C.; Busenberg, Eurybiades

2003-01-01

One of the major water-quality problems in the Chesapeake Bay is an overabundance of nutrients from the streams and rivers that discharge to the Bay. Some of these nutrients are from nonpoint sources such as atmospheric deposition, agricultural manure and fertilizer, and septic systems. The effects of efforts to control nonpoint sources, however, can be difficult to quantify because of the lag time between changes at the land surface and the response in the base-flow (ground water) component of streams. To help resource managers understand the lag time between implementation of management practices and subsequent response in the nutrient concentrations in the base-flow component of streamflow, a study of ground-water discharge, residence time, and nitrate transport in springs throughout the Chesapeake Bay Watershed and in four smaller watersheds in selected hydrogeomorphic regions (HGMRs) was conducted. The four watersheds were in the Coastal Plain Uplands, Piedmont crystalline, Valley and Ridge carbonate, and Valley and Ridge siliciclastic HGMRs.A study of springs to estimate an apparent age of the ground water was based on analyses for concentrations of chlorofluorocarbons in water samples collected from 48 springs in the Chesapeake Bay Watershed. Results of the analysis indicate that median age for all the samples was 10 years, with the 25th percentile having an age of 7 years and the 75th percentile having an age of 13 years. Although the number of samples collected in each HGMR was limited, there did not appear to be distinct differences in the ages between the HGMRs. The ranges were similar between the major HGMRs above the Fall Line (modern to about 50 years), with only two HGMRs of small geographic extent (Piedmont carbonate and Mesozoic Lowland) having ranges of modern to about 10 years. The median values of all the HGMRs ranged from 7 to 11 years. Not enough samples were collected in the Coastal Plain for comparison. Spring samples showed slightly younger

Using Remotely Sensed Data and Watershed and Hydrodynamic Models to Evaluate the Effects of Land Cover Land Use Change on Aquatic Ecosystems in Mobile Bay, AL

Science.gov (United States)

Al-Hamdan, Mohammad Z.; Estes, Maurice G., Jr.; Judd, Chaeli; Thom, Ron; Woodruff, Dana; Ellis, Jean T.; Quattrochi, Dale; Watson, Brian; Rodriquez, Hugo; Johnson, Hoyt

2012-01-01

Alabama coastal systems have been subjected to increasing pressure from a variety of activities including urban and rural development, shoreline modifications, industrial activities, and dredging of shipping and navigation channels. The impacts on coastal ecosystems are often observed through the use of indicator species. One such indicator species for aquatic ecosystem health is submerged aquatic vegetation (SAV). Watershed and hydrodynamic modeling has been performed to evaluate the impact of land cover land use (LCLU) change in the two counties surrounding Mobile Bay (Mobile and Baldwin) on SAV stressors and controlling factors (temperature, salinity, and sediment) in the Mobile Bay estuary. Watershed modeling using the Loading Simulation Package in C++ (LSPC) was performed for all watersheds contiguous to Mobile Bay for LCLU scenarios in 1948, 1992, 2001, and 2030. Remotely sensed Landsat-derived National Land Cover Data (NLCD) were used in the 1992 and 2001 simulations after having been reclassified to a common classification scheme. The Prescott Spatial Growth Model was used to project the 2030 LCLU scenario based on current trends. The LSPC model simulations provided output on changes in flow, temperature, and sediment for 22 discharge points into the estuary. These results were inputted in the Environmental Fluid Dynamics Computer Code (EFDC) hydrodynamic model to generate data on changes in temperature, salinity, and sediment on a grid throughout Mobile Bay and adjacent estuaries. The changes in the aquatic ecosystem were used to perform an ecological analysis to evaluate the impact on SAV habitat suitability. This is the key product benefiting the Mobile Bay coastal environmental managers that integrates the influences of temperature, salinity, and sediment due to LCLU driven flow changes with the restoration potential of SAVs. Data products and results are being integrated into NOAA s EcoWatch and Gulf of Mexico Data Atlas online systems for

Linking the watershed to the schoolshed: teaching sustainable development in K-12 with the Chester RIver Watershed Observatory

Science.gov (United States)

Trembanis, A. C.; Levin, D.; Seidel, J.

2012-12-01

The Chester River has been the subject of ongoing scientific studies in response to both the Clean Water Act and the EPA's Chesapeake Bay Program initiatives. The Upper, Middle, and Lower Chester are on the Maryland Department of Environment's list of "impaired waters". The Chester River Watershed (CRW) Observatory is lead by the Center for Environment & Society at Washington College. Eight clusters representing 22 public and private K-12 schools in the CRW provide the sampling sites distributed throughout the watershed. Weather stations will be installed at these sites allowing monitoring of the watershed's microclimate. Each cluster will be assigned a Basic Observation Buoy (BOB), an easy to assemble inexpensive buoy platform for real-time water column and atmospheric condition measurements. The BOBs are fitted with a data sonde to collect similar data parameters (e.g. salinity, temperature) as the main stem Chesapeake Bay buoys do. These assets will be deployed and the data transmitted to the Chester River Geographic Information System site for archival and visual display. Curriculum already developed for the Chesapeake Bay Interpretive Buoy System by the NOAA Chesapeake Bay Office will be adapted to the Chester River Watershed. Social issues of water sustainability will be introduced using the Watershed Game (Northland NEMO ®). During 2011 NOAA's Chesapeake Bay Office completed curriculum projects including Chesapeake Exploration, Build-a-Buoy (BaBs) and Basic Observation Buoys (BOBs). These engaging projects utilize authentic data and hands-on activities to demonstrate the tools scientists use to understand system interactions in the Bay. Chesapeake Exploration is a collection of online activities that provides teachers and students with unprecedented access to Bay data. Students are guided through a series of tasks that explore topics related to the interrelation between watersheds, land-use, weather, water quality, and living resources. The BaBs and BOBs

Assessing development pressure in the Chesapeake Bay watershed: an evaluation of two land-use change models.

Science.gov (United States)

Claggett, Peter R; Jantz, Claire A; Goetz, Scott J; Bisland, Carin

2004-06-01

Natural resource lands in the Chesapeake Bay watershed are increasingly susceptible to conversion into developed land uses, particularly as the demand for residential development grows. We assessed development pressure in the Baltimore-Washington, DC region, one of the major urban and suburban centers in the watershed. We explored the utility of two modeling approaches for forecasting future development trends and patterns by comparing results from a cellular automata model, SLEUTH (slope, land use, excluded land, urban extent, transportation), and a supply/demand/allocation model, the Western Futures Model. SLEUTH can be classified as a land-cover change model and produces projections on the basis of historic trends of changes in the extent and patterns of developed land and future land protection scenarios. The Western Futures Model derives forecasts from historic trends in housing units, a U.S. Census variable, and exogenously supplied future population projections. Each approach has strengths and weaknesses, and combining the two has advantages and limitations.

Assessing climate change impacts on winter cover crop nitrate uptake efficiency on the coastal plain of the Chesapeake Bay watershed using the SWAT model

Science.gov (United States)

Climate change is expected to exacerbate water quality degradation in the Chesapeake Bay watershed (CBW). Winter cover crops (WCCs) have been widely implemented in this region owing to their high effectiveness at reducing nitrate loads. However, little is known about climate change impacts on the ef...

Spatial and temporal trends in runoff at long-term streamgages within and near the Chesapeake Bay Watershed

Science.gov (United States)

Rice, Karen C.; Hirsch, Robert M.

2012-01-01

Long-term streamflow data within the Chesapeake Bay watershed and surrounding area were analyzed in an attempt to identify trends in streamflow. Data from 30 streamgages near and within the Chesapeake Bay watershed were selected from 1930 through 2010 for analysis. Streamflow data were converted to runoff and trend slopes in percent change per decade were calculated. Trend slopes for three runoff statistics (the 7-day minimum, the mean, and the 1-day maximum) were analyzed annually and seasonally. The slopes also were analyzed both spatially and temporally. The spatial results indicated that trend slopes in the northern half of the watershed were generally greater than those in the southern half. The temporal analysis was done by splitting the 80-year flow record into two subsets; records for 28 streamgages were analyzed for 1930 through 1969 and records for 30 streamgages were analyzed for 1970 through 2010. The mean of the data for all sites for each year were plotted so that the following datasets were analyzed: the 7-day minimum runoff for the north, the 7-day minimum runoff for the south, the mean runoff for the north, the mean runoff for the south, the 1-day maximum runoff for the north, and the 1-day maximum runoff for the south. Results indicated that the period 1930 through 1969 was statistically different from the period 1970 through 2010. For the 7-day minimum runoff and the mean runoff, the latter period had significantly higher streamflow than did the earlier period, although within those two periods no significant linear trends were identified. For the 1-day maximum runoff, no step trend or linear trend could be shown to be statistically significant for the north, although the south showed a mixture of an upward step trend accompanied by linear downtrends within the periods. In no case was a change identified that indicated an increasing rate of change over time, and no general pattern was identified of hydrologic conditions becoming "more extreme

Scientific and technical advisory committee review of the nutrient inputs to the watershed model

Science.gov (United States)

The following is a report by a STAC Review Team concerning the methods and documentation used by the Chesapeake Bay Partnership for evaluation of nutrient inputs to Phase 6 of the Chesapeake Bay Watershed Model. The “STAC Review of the Nutrient Inputs to the Watershed Model” (previously referred to...

Assessing the impacts of future climate conditions on the effectiveness of winter cover crops in reducing nitrate loads into the Chesapeake Bay Watersheds using SWAT model

Science.gov (United States)

Winter cover crops (WCCs) have been widely implemented in the Coastal Plain of the Chesapeake Bay watershed (CBW) due to their high effectiveness at reducing nitrate loads. However, future climate conditions (FCCs) are expected to exacerbate water quality degradation in the CBW by increasing nitrat...

Downscaling future climate projections to the watershed scale: A north San Francisco Bay estuary case study

Science.gov (United States)

Micheli, Elisabeth; Flint, Lorraine; Flint, Alan; Weiss, Stuart; Kennedy, Morgan

2012-01-01

We modeled the hydrology of basins draining into the northern portion of the San Francisco Bay Estuary (North San Pablo Bay) using a regional water balance model (Basin Characterization Model; BCM) to estimate potential effects of climate change at the watershed scale. The BCM calculates water balance components, including runoff, recharge, evapotranspiration, soil moisture, and stream flow, based on climate, topography, soils and underlying geology, and the solar-driven energy balance. We downscaled historical and projected precipitation and air temperature values derived from weather stations and global General Circulation Models (GCMs) to a spatial scale of 270 m. We then used the BCM to estimate hydrologic response to climate change for four scenarios spanning this century (2000–2100). Historical climate patterns show that Marin’s coastal regions are typically on the order of 2 °C cooler and receive five percent more precipitation compared to the inland valleys of Sonoma and Napa because of marine influences and local topography. By the last 30 years of this century, North Bay scenarios project average minimum temperatures to increase by 1.0 °C to 3.1 °C and average maximum temperatures to increase by 2.1 °C to 3.4 °C (in comparison to conditions experienced over the last 30 years, 1981–2010). Precipitation projections for the 21st century vary between GCMs (ranging from 2 to 15% wetter than the 20th-century average). Temperature forcing increases the variability of modeled runoff, recharge, and stream discharge, and shifts hydrologic cycle timing. For both high- and low-rainfall scenarios, by the close of this century warming is projected to amplify late-season climatic water deficit (a measure of drought stress on soils) by 8% to 21%. Hydrologic variability within a single river basin demonstrated at the scale of subwatersheds may prove an important consideration for water managers in the face of climate change. Our results suggest that in arid

Defining a data management strategy for USGS Chesapeake Bay studies

Science.gov (United States)

Ladino, Cassandra

2013-01-01

The mission of U.S. Geological Survey’s (USGS) Chesapeake Bay studies is to provide integrated science for improved understanding and management of the Chesapeake Bay ecosystem. Collective USGS efforts in the Chesapeake Bay watershed began in the 1980s, and by the mid-1990s the USGS adopted the watershed as one of its national place-based study areas. Great focus and effort by the USGS have been directed toward Chesapeake Bay studies for almost three decades. The USGS plays a key role in using “ecosystem-based adaptive management, which will provide science to improve the efficiency and accountability of Chesapeake Bay Program activities” (Phillips, 2011). Each year USGS Chesapeake Bay studies produce published research, monitoring data, and models addressing aspects of bay restoration such as, but not limited to, fish health, water quality, land-cover change, and habitat loss. The USGS is responsible for collaborating and sharing this information with other Federal agencies and partners as described under the President’s Executive Order 13508—Strategy for Protecting and Restoring the Chesapeake Bay Watershed signed by President Obama in 2009. Historically, the USGS Chesapeake Bay studies have relied on national USGS databases to store only major nationally available sources of data such as streamflow and water-quality data collected through local monitoring programs and projects, leaving a multitude of other important project data out of the data management process. This practice has led to inefficient methods of finding Chesapeake Bay studies data and underutilization of data resources. Data management by definition is “the business functions that develop and execute plans, policies, practices and projects that acquire, control, protect, deliver and enhance the value of data and information.” (Mosley, 2008a). In other words, data management is a way to preserve, integrate, and share data to address the needs of the Chesapeake Bay studies to better

Impacts of Watershed Characteristics and Crop Rotations on Winter Cover Crop Nitrate-Nitrogen Uptake Capacity within Agricultural Watersheds in the Chesapeake Bay Region.

Science.gov (United States)

Lee, Sangchul; Yeo, In-Young; Sadeghi, Ali M; McCarty, Gregory W; Hively, W Dean; Lang, Megan W

2016-01-01

The adoption rate of winter cover crops (WCCs) as an effective conservation management practice to help reduce agricultural nutrient loads in the Chesapeake Bay (CB) is increasing. However, the WCC potential for water quality improvement has not been fully realized at the watershed scale. This study was conducted to evaluate the long-term impact of WCCs on hydrology and NO3-N loads in two adjacent watersheds and to identify key management factors that affect the effectiveness of WCCs using the Soil and Water Assessment Tool (SWAT) and statistical methods. Simulation results indicated that WCCs are effective for reducing NO3-N loads and their performance varied based on planting date, species, soil characteristics, and crop rotations. Early-planted WCCs outperformed late-planted WCCs on the reduction of NO3-N loads and early-planted rye (RE) reduced NO3-N loads by ~49.3% compared to the baseline (no WCC). The WCCs were more effective in a watershed dominated by well-drained soils with increased reductions in NO3-N fluxes of ~2.5 kg N·ha-1 delivered to streams and ~10.1 kg N·ha-1 leached into groundwater compared to poorly-drained soils. Well-drained agricultural lands had higher transport of NO3-N in the soil profile and groundwater due to increased N leaching. Poorly-drained agricultural lands had lower NO3-N due to extensive drainage ditches and anaerobic soil conditions promoting denitrification. The performance of WCCs varied by crop rotations (i.e., continuous corn and corn-soybean), with increased N uptake following soybean crops due to the increased soil mineral N availability by mineralization of soybean residue compared to corn residue. The WCCs can reduce N leaching where baseline NO3-N loads are high in well-drained soils and/or when residual and mineralized N availability is high due to the cropping practices. The findings suggested that WCC implementation plans should be established in watersheds according to local edaphic and agronomic

Impacts of Watershed Characteristics and Crop Rotations on Winter Cover Crop Nitrate-Nitrogen Uptake Capacity within Agricultural Watersheds in the Chesapeake Bay Region.

Directory of Open Access Journals (Sweden)

Sangchul Lee

Full Text Available The adoption rate of winter cover crops (WCCs as an effective conservation management practice to help reduce agricultural nutrient loads in the Chesapeake Bay (CB is increasing. However, the WCC potential for water quality improvement has not been fully realized at the watershed scale. This study was conducted to evaluate the long-term impact of WCCs on hydrology and NO3-N loads in two adjacent watersheds and to identify key management factors that affect the effectiveness of WCCs using the Soil and Water Assessment Tool (SWAT and statistical methods. Simulation results indicated that WCCs are effective for reducing NO3-N loads and their performance varied based on planting date, species, soil characteristics, and crop rotations. Early-planted WCCs outperformed late-planted WCCs on the reduction of NO3-N loads and early-planted rye (RE reduced NO3-N loads by ~49.3% compared to the baseline (no WCC. The WCCs were more effective in a watershed dominated by well-drained soils with increased reductions in NO3-N fluxes of ~2.5 kg N·ha-1 delivered to streams and ~10.1 kg N·ha-1 leached into groundwater compared to poorly-drained soils. Well-drained agricultural lands had higher transport of NO3-N in the soil profile and groundwater due to increased N leaching. Poorly-drained agricultural lands had lower NO3-N due to extensive drainage ditches and anaerobic soil conditions promoting denitrification. The performance of WCCs varied by crop rotations (i.e., continuous corn and corn-soybean, with increased N uptake following soybean crops due to the increased soil mineral N availability by mineralization of soybean residue compared to corn residue. The WCCs can reduce N leaching where baseline NO3-N loads are high in well-drained soils and/or when residual and mineralized N availability is high due to the cropping practices. The findings suggested that WCC implementation plans should be established in watersheds according to local edaphic and agronomic

The distribution of phosphorus in Popes Creek, VA, and in the Pocomoke River, MD: Two watersheds with different land management practices in the Chesapeake Bay Basin

Science.gov (United States)

Simon, N.S.; Bricker, O.P.; Newell, W.; McCoy, J.; Morawe, R.

2005-01-01

This paper compares phosphorus (P) concentrations in sediments from two watersheds, one with, and one without, intensive animal agriculture. The watersheds are in the coastal plain of the Chesapeake Bay and have similar physiographic characteristics. Agriculture in the Pocomoke River, MD, watershed supplied 2.7 percent of all broiler chickens produced in the USA in 1997. Poultry litter is an abundant, local source of manure for crops. Broiler chickens are not produced in the Popes Creek, VA, watershed and poultry manure is, therefore, not a major source of fertilizer. The largest concentrations of P in sediment samples are found in floodplain and main-stem bottom sediment in both watersheds. Concentrations of total P and P extracted with 1N HCl are significantly larger in main-stem bottom sediments from the Pocomoke River than in main-stem bottom sediments from Popes Creek. Larger concentrations of P are associated with what are potentially redox sensitive iron oxyhydroxides in sediment samples from the Pocomoke River watershed than are associated with what are potentially redox sensitive iron oxyhydroxides in sediment samples from the Popes Creek watershed. Data for P and iron (Fe) concentrations in sediments from the Popes Creek watershed provide a numerical framework (baseline) with which to compare P and Fe concentrations in sediment from the Pocomoke River watershed. ?? Springer 2005.

Sustainable development in the Hudson Bay/James Bay bioregion

International Nuclear Information System (INIS)

Anon.

1991-01-01

An overview is presented of projects planned for the James Bay/Hudson Bay region, and the expected environmental impacts of these projects. The watershed of James Bay and Hudson Bay covers well over one third of Canada, from southern Alberta to central Ontario to Baffin Island, as well as parts of north Dakota and Minnesota in the U.S.A. Hydroelectric power developments that change the timing and rate of flow of fresh water may cause changes in the nature and duration of ice cover, habitats of marine mammals, fish and migratory birds, currents into and out of Hudson Bay/James Bay, seasonal and annual loads of sediments and nutrients to marine ecosystems, and anadromous fish populations. Hydroelectric projects are proposed for the region by Quebec, Ontario and Manitoba. In January 1992, the Canadian Arctic Resources Committee (CARC), the Environmental Committee of Sanikuluaq, and the Rawson Academy of Arctic Science will launch the Hudson Bay/James Bay Bioregion Program, an independent initiative to apply an ecosystem approach to the region. Two main objectives are to provide a comprehensive assessment of the cumulative impacts of human activities on the marine and freshwater ecosystems of the Hudson Bay/James Bay bioregion, and to foster sustainable development by examining and proposing cooperative processes for decision making among governments, developers, aboriginal peoples and other stakeholders. 1 fig

Watershed Outreach Professionals' Behavior Change Practices, Challenges, and Needs

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Kelly, Meghan; Little, Samuel; Phelps, Kaitlin; Roble, Carrie; Zint, Michaela

2012-01-01

This study investigated the practices, challenges, and needs of Chesapeake Bay watershed outreach professionals, as related to behavior change strategies and best outreach practices. Data were collected through a questionnaire e-mailed to applicants to the Chesapeake Bay Trust's environmental outreach grant program (n = 108, r = 56%). Almost all…

Preliminary estimates of residence times and apparent ages of ground water in the Chesapeake Bay watershed, and water-quality data from a survey of springs

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Focazio, Michael J.; Plummer, Niel; Bohlke, John K.; Busenberg, Eurybiades; Bachman, L. Joseph; Powars, David S.

1998-01-01

Knowledge of the residence times of the ground-water systems in Chesapeake Bay watershed helps resource managers anticipate potential delays between implementation of land-management practices and any improve-ments in river and estuary water quality. This report presents preliminary estimates of ground-water residence times and apparent ages of water in the shallow aquifers of the Chesapeake Bay watershed. A simple reservoir model, published data, and analyses of spring water were used to estimate residence times and apparent ages of ground-water discharge. Ranges of aquifer hydraulic characteristics throughout the Bay watershed were derived from published literature and were used to estimate ground-water residence times on the basis of a simple reservoir model. Simple combinations of rock type and physiographic province were used to delineate hydrogeomorphic regions (HGMR?s) for the study area. The HGMR?s are used to facilitate organization and display of the data and analyses. Illustrations depicting the relation of aquifer characteristics and associated residence times as a continuum for each HGMR were developed. In this way, the natural variation of aquifer characteristics can be seen graphically by use of data from selected representative studies. Water samples collected in September and November 1996, from 46 springs throughout the watershed were analyzed for chlorofluorocarbons (CFC?s) to estimate the apparent age of ground water. For comparison purposes, apparent ages of water from springs were calculated assuming piston flow. Additi-onal data are given to estimate apparent ages assuming an exponential distribution of ages in spring discharge. Additionally, results from previous studies of CFC-dating of ground water from other springs and wells in the watershed were compiled. The CFC data, and the data on major ions, nutrients, and nitrogen isotopes in the water collected from the 46 springs are included in this report. The apparent ages of water

Use of Principal Components Analysis to Explain Controls on Nutrient Fluxes to the Chesapeake Bay

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Rice, K. C.; Mills, A. L.

2017-12-01

The Chesapeake Bay watershed, on the east coast of the United States, encompasses about 166,000-square kilometers (km2) of diverse land use, which includes a mixture of forested, agricultural, and developed land. The watershed is now managed under a Total Daily Maximum Load (TMDL), which requires implementation of management actions by 2025 that are sufficient to reduce nitrogen, phosphorus, and suspended-sediment fluxes to the Chesapeake Bay and restore the bay's water quality. We analyzed nutrient and sediment data along with land-use and climatic variables in nine sub watersheds to better understand the drivers of flux within the watershed and to provide relevant management implications. The nine sub watersheds range in area from 300 to 30,000 km2, and the analysis period was 1985-2014. The 31 variables specific to each sub watershed were highly statistically significantly correlated, so Principal Components Analysis was used to reduce the dimensionality of the dataset. The analysis revealed that about 80% of the variability in the whole dataset can be explained by discharge, flux, and concentration of nutrients and sediment. The first two principal components (PCs) explained about 68% of the total variance. PC1 loaded strongly on discharge and flux, and PC2 loaded on concentration. The PC scores of both PC1 and PC2 varied by season. Subsequent analysis of PC1 scores versus PC2 scores, broken out by sub watershed, revealed management implications. Some of the largest sub watersheds are largely driven by discharge, and consequently large fluxes. In contrast, some of the smaller sub watersheds are more variable in nutrient concentrations than discharge and flux. Our results suggest that, given no change in discharge, a reduction in nutrient flux to the streams in the smaller watersheds could result in a proportionately larger decrease in fluxes of nutrients down the river to the bay, than in the larger watersheds.

Reducing methylmercury accumulation in the food webs of San Francisco Bay and its local watersheds

International Nuclear Information System (INIS)

Davis, J.A.; Looker, R.E.; Yee, D.; Marvin-Di Pasquale, M.; Grenier, J.L.; Austin, C.M.; McKee, L.J.; Greenfield, B.K.; Brodberg, R.; Blum, J.D.

2012-01-01

San Francisco Bay (California, USA) and its local watersheds present an interesting case study in estuarine mercury (Hg) contamination. This review focuses on the most promising avenues for attempting to reduce methylmercury (MeHg) contamination in Bay Area aquatic food webs and identifying the scientific information that is most urgently needed to support these efforts. Concern for human exposure to MeHg in the region has led to advisories for consumption of sport fish. Striped bass from the Bay have the highest average Hg concentration measured for this species in USA estuaries, and this degree of contamination has been constant for the past 40 years. Similarly, largemouth bass in some Bay Area reservoirs have some of the highest Hg concentrations observed in the entire US. Bay Area wildlife, particularly birds, face potential impacts to reproduction based on Hg concentrations in the tissues of several Bay species. Source control of Hg is one of the primary possible approaches for reducing MeHg accumulation in Bay Area aquatic food webs. Recent findings (particularly Hg isotope measurements) indicate that the decades-long residence time of particle-associated Hg in the Bay is sufficient to allow significant conversion of even the insoluble forms of Hg into MeHg. Past inputs have been thoroughly mixed throughout this shallow and dynamic estuary. The large pool of Hg already present in the ecosystem dominates the fraction converted to MeHg and accumulating in the food web. Consequently, decreasing external Hg inputs can be expected to reduce MeHg in the food web, but it will likely take many decades to centuries before those reductions are achieved. Extensive efforts to reduce loads from the largest Hg mining source (the historic New Almaden mining district) are underway. Hg is spread widely across the urban landscape, but there are a number of key sources, source areas, and pathways that provide opportunities to capture larger quantities of Hg and reduce loads

Reducing methylmercury accumulation in the food webs of San Francisco Bay and its local watersheds

Energy Technology Data Exchange (ETDEWEB)

Davis, J.A., E-mail: jay@sfei.org [San Francisco Estuary Institute, 4911 Central Avenue, Richmond, CA 94804 (United States); Looker, R.E. [San Francisco Bay Regional Water Quality Control Board, 1515 Clay Street, Suite 1400, Oakland, CA 94612 (United States); Yee, D. [San Francisco Estuary Institute, 4911 Central Avenue, Richmond, CA 94804 (United States); Marvin-Di Pasquale, M. [U.S. Geological Survey, Water Resources Division/MS 480, 345 Middlefield Road, Menlo Park, CA 94025 (United States); Grenier, J.L. [San Francisco Estuary Institute, 4911 Central Avenue, Richmond, CA 94804 (United States); Austin, C.M. [San Francisco Bay Regional Water Quality Control Board, 1515 Clay Street, Suite 1400, Oakland, CA 94612 (United States); McKee, L.J.; Greenfield, B.K. [San Francisco Estuary Institute, 4911 Central Avenue, Richmond, CA 94804 (United States); Brodberg, R. [California Office of Environmental Health Hazard Assessment, California Environmental Protection Agency, 1001 I Street, Sacramento, CA 95812 (United States); Blum, J.D. [Department of Geological Sciences, University of Michigan, 1100 North University Avenue, Ann Arbor, MI 48109 (United States)

2012-11-15

San Francisco Bay (California, USA) and its local watersheds present an interesting case study in estuarine mercury (Hg) contamination. This review focuses on the most promising avenues for attempting to reduce methylmercury (MeHg) contamination in Bay Area aquatic food webs and identifying the scientific information that is most urgently needed to support these efforts. Concern for human exposure to MeHg in the region has led to advisories for consumption of sport fish. Striped bass from the Bay have the highest average Hg concentration measured for this species in USA estuaries, and this degree of contamination has been constant for the past 40 years. Similarly, largemouth bass in some Bay Area reservoirs have some of the highest Hg concentrations observed in the entire US. Bay Area wildlife, particularly birds, face potential impacts to reproduction based on Hg concentrations in the tissues of several Bay species. Source control of Hg is one of the primary possible approaches for reducing MeHg accumulation in Bay Area aquatic food webs. Recent findings (particularly Hg isotope measurements) indicate that the decades-long residence time of particle-associated Hg in the Bay is sufficient to allow significant conversion of even the insoluble forms of Hg into MeHg. Past inputs have been thoroughly mixed throughout this shallow and dynamic estuary. The large pool of Hg already present in the ecosystem dominates the fraction converted to MeHg and accumulating in the food web. Consequently, decreasing external Hg inputs can be expected to reduce MeHg in the food web, but it will likely take many decades to centuries before those reductions are achieved. Extensive efforts to reduce loads from the largest Hg mining source (the historic New Almaden mining district) are underway. Hg is spread widely across the urban landscape, but there are a number of key sources, source areas, and pathways that provide opportunities to capture larger quantities of Hg and reduce loads

Assessing wetland loss impacts on watershed hydrology using an improved modeling approach

Science.gov (United States)

Despite the importance of wetland impacts on water cycling, the Chesapeake Bay Watershed (CBW) has experienced significant wetland losses. The resultant environmental degradation has not been fully characterized. Our aim is to assess wetland loss impacts on watershed hydrology for an agricultural wa...

Community implementation dynamics: Nutrient management in the New York City and Chesapeake Bay Watersheds

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Glenn Earl Sterner

2015-04-01

Full Text Available The creation of natural resource management and conservation strategies can be affected by engagement with local citizens and competing interests between agencies and stakeholders at the varying levels of governance. This paper examines the role of local engagement and the interaction between governance levels on the outcomes of nutrient management policy, a specific area of natural resource conservation and management. Presented are two case studies of the New York City and Chesapeake Bay Watersheds in the US. These case studies touch upon the themes of local citizen engagement and governance stakeholder interaction in changing nutrient management to improve water quality. An analysis of these cases leads to several key considerations for the creation and implementation of nutrient management and natural resource management more broadly, including the importance of: local citizen engagement, government brokering and cost sharing; and the need of all stakeholders to respect each other in the policy creation and implementation process.

A Decision Framework to Protect Coral Reefs in Guánica Bay, Puerto Rico

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A Watershed Management Plan (WMP) for Guánica Bay, Puerto Rico, was introduced in 2008 by a nonprofit organization, the Center for Watershed Protection, with the intent of protecting coral reefs from damage related to watershed discharges. The plan was initially generated with th...

The Lower Chesapeake Bay LTAR: A coastal urban-agricultural region

Science.gov (United States)

Mccarty, G.; Alfieri, J. G.; Cavigelli, M.; Cosh, M. H.; Hapeman, C. J.; Kustas, W. P.; Maul, J.; Mirsky, S.; Pooler, M.; Sadeghi, A. M.; Schomberg, H.; Timlin, D. J.; Rice, C. P.

2015-12-01

The Chesapeake Bay, located in the mid-Atlantic region of the U.S., is the largest estuary in North America. The watershed area includes six states from New York to Virginia and is nearly 167,000 km2 in size with more than 150 rivers and streams entering the 300-km Bay main stem. Forested and agricultural lands make up 58 and 22 percent of the land use, respectively. Nearly 9 percent is urban and suburban use, and the watershed is home to over 17 million people. However, the population is expected to reach 19 million by 2025, raising the potential for conflict between the agricultural and urban communities over land and water use and in protecting natural resources, especially in the lower portion of the Chesapeake Bay watershed. The Lower Chesapeake Bay study area, part of the USDA-ARS Long-Term Agroecosystem Research (LTAR) network, will provide much-needed data to support decisions at this critical agriculture-urban interface. Current long-term projects seek to assess the economic, production, and environmental performance of conventional and organic cropping systems and to evaluate the resilience of these systems to climate change. Large-scale studies are being conducted to examine the effects of land-use and landscape characteristics on ecosystem services and on energy, water, nutrient, carbon, and pest dynamics within watersheds. New in-situ measurement and remote sensor technologies are being considered with the expectancy that the data streams will be available on-line and for use in modeling. Results and outcomes of these research efforts will greatly benefit the national LTAR network and will be applicable to other US coastal urban-agricultural regions.

Riverine discharges to Chesapeake Bay: Analysis of long-term (1927–2014) records and implications for future flows in the Chesapeake Bay basin

Science.gov (United States)

Rice, Karen; Moyer, Douglas; Mills, Aaron L.

2017-01-01

The Chesapeake Bay (CB) basin is under a total maximum daily load (TMDL) mandate to reduce nitrogen, phosphorus, and sediment loads to the bay. Identifying shifts in the hydro-climatic regime may help explain observed trends in water quality. To identify potential shifts, hydrologic data (1927–2014) for 27 watersheds in the CB basin were analyzed to determine the relationships among long-term precipitation and stream discharge trends. The amount, frequency, and intensity of precipitation increased from 1910 to 1996 in the eastern U.S., with the observed increases greater in the northeastern U.S. than the southeastern U.S. The CB watershed spans the north-to-south gradient in precipitation increases, and hydrologic differences have been observed in watersheds north relative to watersheds south of the Pennsylvania—Maryland (PA-MD) border. Time series of monthly mean precipitation data specific to each of 27 watersheds were derived from the Precipitation-elevation Regression on Independent Slopes Model (PRISM) dataset, and monthly mean stream-discharge data were obtained from U.S. Geological Survey streamgage records. All annual precipitation trend slopes in the 18 watersheds north of the PA-MD border were greater than or equal to those of the nine south of that border. The magnitude of the trend slopes for 1927–2014 in both precipitation and discharge decreased in a north-to-south pattern. Distributions of the monthly precipitation and discharge datasets were assembled into percentiles for each year for each watershed. Multivariate correlation of precipitation and discharge within percentiles among the groups of northern and southern watersheds indicated only weak associations. Regional-scale average behaviors of trends in the distribution of precipitation and discharge annual percentiles differed between the northern and southern watersheds. In general, the linkage between precipitation and discharge was weak, with the linkage weaker in the northern watersheds

Seasonal, Spatial Distribution and Ecological Risk Assessment of Heavy Metals in Surface Sediments from a Watershed Area in Gonghu Bay in Taihu Lake, China

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Peifang Wang

2014-01-01

Full Text Available Surface sediments from five stations within Gonghu Bay in Taihu Lake, China, were sampled for seasonal and spatial metal contamination analysis variations and ecological risks assessment from April 2009 to January 2010. The Contamination Factor (CF and geo-accumulation index (Igeo indicated that the sediments in Gonghu Bay ranged from unpolluted to moderately polluted, except for Cd. The one-way ANOVA analysis results showed that the Pb, Zn, Cr, and Cu concentrations were higher at station 3 (lake inlet and the Cr, Pb, and Zn concentrations were significantly higher in the spring. Additionally, using BCR¡¦s sequential extraction, the results showed that the fractionated metals Zn and Cd were observed as bioavailable fractions in the sediments, which could have potential moderate mobility in the water system. There was a significant increase in the bioavailable form during winter. The ratio of secondary and primary phrase (RSP decreased according to the order Zn > Cu > Ni > Pb > Cd > Cr. Finally, these results indicated that the sediments of Gonghu Bay were polluted by Cd, Zn, and Cu, which provides a scientific basis for effectively protecting sediments in watershed areas from long-term heavy metal accumulation.

Phosphorus export across an urban to rural gradient in the Chesapeake Bay watershed

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Shuiwang Duan; Sujay S. Kaushal; Peter Groffman; Lawrence E. Band; Kenneth Belt

2012-01-01

Watershed export of phosphorus (P) from anthropogenic sources has contributed to eutrophication in freshwater and coastal ecosystems. We explore impacts of watershed urbanization on the magnitude and export flow distribution of P along an urban-rural gradient in eight watersheds monitored as part of the Baltimore Ecosystem Study Long-Term Ecological Research site....

Estuary 2100 Project, Phase 2: Building Partnerships for Resilient Watersheds

Science.gov (United States)

Information about the SFBWQP Estuary 2100 Project, Phase 2: Building Partnerships for Resilient Watersheds, part of an EPA competitive grant program to improve SF Bay water quality focused on restoring impaired waters and enhancing aquat

An Assessment of Potential Mining Impacts on Salmon Ecosystems of Bristol Bay, Alaska (Final Report)

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The Bristol Bay watershed in southwestern Alaska supports the largest sockeye salmon fishery in the world, is home to 25 federally recognized tribal governments, and contains large mineral resources. The potential for large-scale mining activities in the watershed has raised conc...

Meaningful Watershed Experiences for Middle and High School Students

Science.gov (United States)

Landry, Melinda; Smith, Cynthia; Greene, Joy

2014-05-01

Prince William County Public Schools and George Mason University in Virginia, USA, partnered to provide Meaningful Watershed Educational Experiences (MWEEs) for over 25,000 middle and high school students (11-18 year olds) across 34 schools. This school district, situated in a rapidly growing region 55 km southwest of Washington DC, has over 82,000 K-12 students. As native forest cover has been replaced with farming and urbanization, water quality has significantly degraded in the 166,534 km2 Chesapeake Bay watershed. This project was designed to increase student awareness of their impact on the land and waters of the largest estuary in the United States. MWEE is a long-term comprehensive project that incorporates a classroom preparation phase, a hands-on outdoor field investigation, and a reflection and data-sharing component. Training and technical assistance enhances the capacity of teachers of 6th grade, high school Earth Science and Environmental Science to deliver MWEEs which includes schoolyard stewardship, inquiry driven field study, use of hand-held technology and computer based mapping and analysis, project sharing and outreach. George Mason University researchers worked closely with K-12 science educators to create a comprehensive watershed-focused curriculum. Graduate and undergraduate students with strong interests in environmental science and education were trained to deliver the field investigation component of the MWEE. Representative teachers from each school were provided 3 days of professional development and were responsible for the training of their school's science education team. A comprehensive curriculum provided teachers with activities and tools designed to enhance students' mastery of state science objectives. Watershed concepts were used as the unifying theme to support student understanding of curriculum and STEM objectives including: scientific investigation, data collection and communication, chemistry, energy, erosion, human

Water quality dynamics in an urbanizing subtropical estuary(Oso Bay, Texas).

Science.gov (United States)

Wetz, Michael S; Hayes, Kenneth C; Fisher, Kelsey V B; Price, Lynn; Sterba-Boatwright, Blair

2016-03-15

Results are presented from a study of water quality dynamics in a shallow subtropical estuary, Oso Bay, Texas, which has a watershed that has undergone extensive urbanization in recent decades. High inorganic nutrient, dissolved organic matter and chlorophyll concentrations, as well as low pH (Oso Bay that receives wastewater effluent. Despite being shallow (Oso Bay, suggesting that it may be exported to adjacent Corpus Christi Bay and contribute to seasonal hypoxia development in that system as well. These results argue for wastewater nutrient input reductions in order to alleviate the symptoms of eutrophication. Copyright © 2016 Elsevier Ltd. All rights reserved.

Integrating science and resource management in Tampa Bay, Florida

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Yates, Kimberly K.; Greening, Holly; Morrison, Gerold

2011-01-01

Tampa Bay is recognized internationally for its remarkable progress towards recovery since it was pronounced "dead" in the late 1970s. Due to significant efforts by local governments, industries and private citizens throughout the watershed, water clarity in Tampa Bay is now equal to what it was in 1950, when population in the watershed was less than one-quarter of what it is today. Seagrass extent has increased by more than 8,000 acres since the mid-1980s, and fish and wildlife populations are increasing. Central to this successful turn-around has been the Tampa Bay resource management community's long-term commitment to development and implementation of strong science-based management strategies. Research institutions and agencies, including Eckerd College, the Florida Wildlife Commission Fish and Wildlife Research Institute, Mote Marine Laboratory, National Oceanic and Atmospheric Administration, the Southwest Florida Water Management District, University of South Florida, U.S. Environmental Protection Agency, U.S. Geological Survey, local and State governments, and private companies contribute significantly to the scientific basis of our understanding of Tampa Bay's structure and ecological function. Resource management agencies, including the Tampa Bay Regional Planning Council's Agency on Bay Management, the Southwest Florida Water Management District's Surface Water Improvement and Management Program, and the Tampa Bay Estuary Program, depend upon this scientific basis to develop and implement regional adaptive management programs. The importance of integrating science with management has become fully recognized by scientists and managers throughout the region, State and Nation. Scientific studies conducted in Tampa Bay over the past 10–15 years are increasingly diverse and complex, and resource management programs reflect our increased knowledge of geology, hydrology and hydrodynamics, ecology and restoration techniques. However, a synthesis of this

Management case study: Tampa Bay, Florida

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Morrison, G.; Greening, H.S.; Yates, K.K.

2012-01-01

Tampa Bay, Florida,USA, is a shallow,subtropical estuary that experienced severe cultural eutrophication between the 1940s and 1980s, a period when the human population of its watershed quadrupled. In response, citizen action led to the formation of a public- and private-sector partnership (the Tampa Bay Estuary Program), which adopted a number of management objectives to support the restoration and protection of the bay’s living resources. These included numeric chlorophyll a and water-clarity targets, as well as long-term goals addressing the spatial extent of sea grasses and other selected habitat types, to support estuarine-dependent faunal guilds.

Characterizing the Organic Matter in Surface Sediments from the San Juan Bay Estuary,

Science.gov (United States)

The San Juan Bay Estuary (SJBE) is located on the north coast of Puerto Rico and includes the San Juan Bay, San José Lagoon, La Torrecilla Lagoon and Piñones Lagoon, as well as the Martín Peña and the Suárez Canals. The SJBE watershed has the highest...

Estuary 2100 Project, Phase 1: Resilient Watersheds for a Changing Climate

Science.gov (United States)

Information about the SFBWQP Estuary 2100 Project, Phase 1: Resilient Watersheds for a Changing Climate , part of an EPA competitive grant program to improve SF Bay water quality focused on restoring impaired waters and enhancing aquatic resources.

Development and implications of a sediment budget for the upper Elk River watershed, Humboldt County

Science.gov (United States)

Lee H. MacDonald; Michael W. Miles; Shane Beach; Nicolas M. Harrison; Matthew R. House; Patrick Belmont; Ken L. Ferrier

2017-01-01

A number of watersheds on the North Coast of California have been designated as sediment impaired under the Clean Water Act, including the 112 km2 upper Elk River watershed that flows into Humboldt Bay just south of Eureka. The objectives of this paper are to: 1) briefly explain the geomorphic context and anthropogenic uses of the Elk River...

Coastal circulation and sediment dynamics in Pelekane and Kawaihae Bays, Hawaii--measurements of waves, currents, temperature, salinity, turbidity, and geochronology: November 2010--March 2011

Science.gov (United States)

Storlazzi, Curt D.; Field, Michael E.; Presto, M. Katherine; Swarzenski, Peter W.; Logan, Joshua B.; Reiss, Thomas E.; Elfers, Timothy C.; Cochran, Susan A.; Torresan, Michael E.; Chezar, Hank

2012-01-01

Coral reef communities on the Island of Hawaii have been heavily affected by the construction of Kawaihae Harbor in the 1950s and by subsequent changes in land use in the adjacent watershed. Sedimentation and other forms of land-based pollution have led to declines in water quality and coral reef health over the past two decades (Tissot, 1998). Erosion mitigation efforts are underway on land, and there is a need to evaluate the impact of these actions on the adjacent coastal ecosystem. The Kohala Center and Kohala Watershed Partnership was awarded $2.69 million from the National Oceanographic and Atmospheric Administration’s (NOAA) Restoration Center as part of the American Recovery and Reinvestment Act of 2009 to stabilize soil and improve land-use practices in the Pelekane Bay watershed. The grant allowed the Kohala Watershed Partnership to implement various upland watershed management activities to reduce land-based sources of pollution into Pelekane Bay. However, a number of questions must be answered in order to: (1) evaluate the effectiveness of the terrestrial watershed remediation efforts; (2) understand the potential of the local marine ecosystem to recover; and (3) understand the potential threat that existing mud deposits in the bay pose to adjacent, relatively pristine coral reef ecosystems. The goal of this experiment was to help address these questions and establish a framework to evaluate the success of the Kohala Watershed Partnership restoration efforts. This research program will also provide resource managers with information relevant to other watershed restoration efforts currently being planned in neighboring watersheds. This project involved an interdisciplinary team of coral reef biologists from the University of Hawaii Coral Reef Assessment and Monitoring Program, who focused on the impact of sedimentation on the biota of Pelekane Bay, and a team of geologists and oceanographers from the U.S. Geological Survey (USGS), who focused on the

Identifying Watershed Regions Sensitive to Soil Erosion and Contributing to Lake Eutrophication—A Case Study in the Taihu Lake Basin (China)

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Lin, Chen; Ma, Ronghua; He, Bin

2015-01-01

Taihu Lake in China is suffering from severe eutrophication partly due to non-point pollution from the watershed. There is an increasing need to identify the regions within the watershed that most contribute to lake water degradation. The selection of appropriate temporal scales and lake indicators is important to identify sensitive watershed regions. This study selected three eutrophic lake areas, including Meiliang Bay (ML), Zhushan Bay (ZS), and the Western Coastal region (WC), as well as multiple buffer zones next to the lake boundary as the study sites. Soil erosion intensity was designated as a watershed indicator, and the lake algae area was designated as a lake quality indicator. The sensitive watershed region was identified based on the relationship between these two indicators among different lake divisions for a temporal sequence from 2000 to 2012. The results show that the relationship between soil erosion modulus and lake quality varied among different lake areas. Soil erosion from the two bay areas was more closely correlated with water quality than soil erosion from the WC region. This was most apparent at distances of 5 km to 10 km from the lake, where the r2 was as high as 0.764. Results indicate that soil erosion could be used as an indicator for identifying key watershed protection areas. Different lake areas need to be considered separately due to differences in geographical features, land use, and the corresponding effects on lake water quality. PMID:26712772

Identifying Watershed Regions Sensitive to Soil Erosion and Contributing to Lake Eutrophication--A Case Study in the Taihu Lake Basin (China).

Science.gov (United States)

Lin, Chen; Ma, Ronghua; He, Bin

2015-12-24

Taihu Lake in China is suffering from severe eutrophication partly due to non-point pollution from the watershed. There is an increasing need to identify the regions within the watershed that most contribute to lake water degradation. The selection of appropriate temporal scales and lake indicators is important to identify sensitive watershed regions. This study selected three eutrophic lake areas, including Meiliang Bay (ML), Zhushan Bay (ZS), and the Western Coastal region (WC), as well as multiple buffer zones next to the lake boundary as the study sites. Soil erosion intensity was designated as a watershed indicator, and the lake algae area was designated as a lake quality indicator. The sensitive watershed region was identified based on the relationship between these two indicators among different lake divisions for a temporal sequence from 2000 to 2012. The results show that the relationship between soil erosion modulus and lake quality varied among different lake areas. Soil erosion from the two bay areas was more closely correlated with water quality than soil erosion from the WC region. This was most apparent at distances of 5 km to 10 km from the lake, where the r² was as high as 0.764. Results indicate that soil erosion could be used as an indicator for identifying key watershed protection areas. Different lake areas need to be considered separately due to differences in geographical features, land use, and the corresponding effects on lake water quality.

Willingness to Pay Survey for Chesapeake Bay Total Maximum Daily Load

Science.gov (United States)

A stated preference survey to collect data on households’ use of Chesapeake Bay and its watershed, and of their preferences for a variety of water quality improvements likely to follow from pollution reduction programs.

Future trends in urbanization and coastal water pollution in the Bay of Bengal: the lived experience

NARCIS (Netherlands)

Zinia, N.J.; Kroeze, C.

2015-01-01

The Bay of Bengal includes coastal seas of several countries, including Bangladesh, India, and Myanmar. We present scenarios for future river export of eutrophying nutrients into the Bay of Bengal, and the role of urbanization therein. We used NEWS (Nutrient Export from WaterSheds) model to analyze

THE EFFECTS OF LAND-USE/LAND-COVER, GEOMORPHOLOGY AND CLIMATE ON MAGNITUDE AND TIMING OF NUTRIENT EXPORT AND LOADING RATES IN THREE COASTAL PLAIN WATERSHEDS

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Watershed nitrogen (N), phosphorus (P), organic carbon (OC), and total suspended sediment (TSS) export rates were determined in 18 sub-basins of three watershed-estuarine systems over two annual cycles (2000 and 2001). The three watersheds all drain to the Mobile Bay estuary and ...

Investigating water use over the Choptank River Watershed using a multisatellite data fusion approach

Science.gov (United States)

Sun, Liang; Anderson, Martha C.; Gao, Feng; Hain, Christopher; Alfieri, Joseph G.; Sharifi, Amirreza; McCarty, Gregory W.; Yang, Yun; Yang, Yang; Kustas, William P.; McKee, Lynn

2017-07-01

The health of the Chesapeake Bay ecosystem has been declining for several decades due to high levels of nutrients and sediments largely tied to agricultural production systems. Therefore, monitoring of agricultural water use and hydrologic connections between crop lands and Bay tributaries has received increasing attention. Remote sensing retrievals of actual evapotranspiration (ET) can provide valuable information in support of these hydrologic modeling efforts, spatially and temporally describing consumptive water use by crops and natural vegetation and quantifying response to expansion of irrigated area occurring with Bay watershed. In this study, a multisensor satellite data fusion methodology, combined with a multiscale ET retrieval algorithm, was applied over the Choptank River watershed located within the Lower Chesapeake Bay region on the Eastern Shore of Maryland, USA to produce daily 30 m resolution ET maps. ET estimates directly retrieved on Landsat satellite overpass dates have high accuracy with relative error (RE) of 9%, as evaluated using flux tower measurements. The fused daily ET time series have reasonable errors of 18% at the daily time step - an improvement from 27% errors using standard Landsat-only interpolation techniques. Annual water consumption by different land cover types was assessed, showing reasonable distributions of water use with cover class. Seasonal patterns in modeled crop transpiration and soil evaporation for dominant crop types were analyzed, and agree well with crop phenology at field scale. Additionally, effects of irrigation occurring during a period of rainfall shortage were captured by the fusion program. These results suggest that the ET fusion system will have utility for water management at field and regional scales over the Eastern Shore. Further efforts are underway to integrate these detailed water use data sets into watershed-scale hydrologic models to improve assessments of water quality and inform best

Urban Effects on Microbial Processes and Food Webs in Coastal Watershed Streams

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We conducted a stream survey in the Narragansett Bay Watershed that targeted a gradient of development intensity and examined how associated changes in nutrients, carbon, and stressors affected periphyton and macroinvertebrates. Concentrations of nutrients, cations, and anions we...

Water quality in South San Francisco Bay, California: current condition and potential issues for the South Bay Salt Pond Restoration Project.

Science.gov (United States)

Grenier, J Letitia; Davis, Jay A

2010-01-01

The SBSPRP is an extensive tidal wetland restoration project that is underway at the margin of South San Francisco Bay, California. The Project, which aims to restore former salt ponds to tidal marsh and manage other ponds for water bird support, is taking place in the context of a highly urbanized watershed and an Estuary already impacted by chemical contaminants. There is an intimate relationship between water quality in the watershed, the Bay, and the transitional wetland areas where the Project is located. The Project seeks to restore habitat for endangered and endemic species and to provide recreational opportunities for people. Therefore, water quality and bioaccumulation of contaminants in fish and wildlife is an important concern for the success of the Project. Mercury, PCBs, and PBDEs are the persistent contaminants of greatest concern in the region. All of these contaminants are present at elevated concentrations both in the abiotic environment and in wildlife. Dioxins, pyrethroids, PAHs, and selenium are also problematic. Organochlorine insecticides have historically impacted the Bay, and they remain above thresholds for concern in a small proportion of samples. Emerging contaminants, such as PFCs and non-PBDE flame retardants, are also an important water quality issue. Beyond chemical pollutants, other concerns for water quality in South San Francisco Bay exist, and include biological constituents, especially invasive species, and chemical attributes, such as dissolved oxygen and salinity. Future changes, both from within the Project and from the Bay and watershed, are likely to influence water quality in the region. Project actions to restore wetlands could worsen, improve, or not affect the already impaired water quality in South Bay. Accelerated erosion of buried sediment as a consequence of Project restoration actions is a potentially serious regional threat to South Bay water and sediment quality. Furthermore, the planned restoration of salt ponds

Connecting Past to Present and Watersheds to Ocean: Modeling 165 Years of Incremental Changes to Flows into the San Francisco Bay Delta System

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MacVean, L. J.; Thompson, S. E.; Huttom, P. H.; Sivapalan, M.

2016-02-01

California's Sacramento-San Joaquin Delta sits at the intersection of vast agricultural and population centers, and supplies fresh water for the diverse and often competing needs of ecosystems, farmers, and millions of Californians. Managing and allocating this resource is a complex feat of economics, politics, and engineering, made increasingly contentious by the ongoing drought. The objective of this research is to augment the scientific foundation of management decisions by addressing the question of how flows into the Delta have evolved in response to human intervention since 1850. In particular, quantifying the dynamic components of water usage through vegetative uptake and evapotranspiration, groundwater recharge, flood conveyance, and water exports at incremental levels of development is a key ambition. This approach emphasizes the built environment, which is subject to the local regulatory framework, rather than climate change, which is generally considered immovable without united global effort. This work encompasses the creation of a hydrologic model representing the watersheds of the San Francisco Bay-Delta system, and quantifies the impacts of changes in land use and the gradual construction of levees, reservoirs, and diversion infrastructure. The model is run using the same climatological forcing at each level of development, thus elucidating the effects of local anthropogenic activity on the Delta and the inflows to the San Francisco Bay estuary. Our results provide a timeline of change, giving decision-makers a scientifically established baseline to aid in the sustainable management of the Bay-Delta system.

QUANTIFYING SEDIMENT CONTRIBUTIONS TO THE GUÁNICA BAY PUERTO RICO

Science.gov (United States)

The island of Puerto Rico faces considerable challenges regarding sustainable land use and effects of land use on adjacent freshwater and marine ecosystem services. In watersheds feeding Guánica Bay (southwestern Puerto Rico), increased soil erosion and sediment loading to strea...

Economics of wild salmon ecosystems: Bristol Bay, Alaska

Science.gov (United States)

John W. Duffield; Christopher J. Neher; David A. Patterson; Oliver S. Goldsmith

2007-01-01

This paper provides an estimate of the economic value of wild salmon ecosystems in the major watershed of Bristol Bay, Alaska. The analysis utilizes both regional economic and social benefit-cost accounting frameworks. Key sectors analyzed include subsistence, commercial fishing, sport fishing, hunting, and nonconsumptive wildlife viewing and tourism. The mixed cash-...

Evaluating the Impact of Land Use Change on Submerged Aquatic Vegetation Stressors in Mobile Bay

Science.gov (United States)

Al-Hamdan, Mohammad; Estes, Maurice G., Jr.; Quattrochi, Dale; Thom, Ronald; Woodruff, Dana; Judd, Chaeli; Ellis, Jean; Watson, Brian; Rodriquez, Hugo; Johnson, Hoyt

2009-01-01

Alabama coastal systems have been subjected to increasing pressure from a variety of activities including urban and rural development, shoreline modifications, industrial activities, and dredging of shipping and navigation channels. The impacts on coastal ecosystems are often observed through the use of indicator species. One such indicator species for aquatic ecosystem health is submerged aquatic vegetation (SAV). Watershed and hydrodynamic modeling has been performed to evaluate the impact of land use change in Mobile and Baldwin counties on SAV stressors and controlling factors (temperature, salinity, and sediment) in Mobile Bay. Watershed modeling using the Loading Simulation Package in C++ (LSPC) was performed for all watersheds contiguous to Mobile Bay for land use scenarios in 1948, 1992, 2001, and 2030. Landsat-derived National Land Cover Data (NLCD) were used in the 1992 and 2001 simulations after having been reclassified to a common classification scheme. The Prescott Spatial Growth Model was used to project the 2030 land use scenario based on current trends. The LSPC model simulations provided output on changes in flow, temperature, and sediment for 22 discharge points into the Bay. Theses results were inputted in the Environmental Fluid Dynamics Computer Code (EFDC) hydrodynamic model to generate data on changes in temperature, salinity, and sediment on a grid with four vertical profiles throughout Mobile Bay. The changes in the aquatic ecosystem were used to perform an ecological analysis to evaluate the impact on SAV habitat suitability. This is the key product benefiting the Mobile Bay coastal environmental managers that integrates the influences of temperature, salinity, and sediment due to land use driven flow changes with the restoration potential of SAVs.

Optimal hydrograph separation using a recursive digital filter constrained by chemical mass balance, with application to selected Chesapeake Bay watersheds

Science.gov (United States)

Raffensperger, Jeff P.; Baker, Anna C.; Blomquist, Joel D.; Hopple, Jessica A.

2017-06-26

Quantitative estimates of base flow are necessary to address questions concerning the vulnerability and response of the Nation’s water supply to natural and human-induced change in environmental conditions. An objective of the U.S. Geological Survey National Water-Quality Assessment Project is to determine how hydrologic systems are affected by watershed characteristics, including land use, land cover, water use, climate, and natural characteristics (geology, soil type, and topography). An important component of any hydrologic system is base flow, generally described as the part of streamflow that is sustained between precipitation events, fed to stream channels by delayed (usually subsurface) pathways, and more specifically as the volumetric discharge of water, estimated at a measurement site or gage at the watershed scale, which represents groundwater that discharges directly or indirectly to stream reaches and is then routed to the measurement point.Hydrograph separation using a recursive digital filter was applied to 225 sites in the Chesapeake Bay watershed. The recursive digital filter was chosen for the following reasons: it is based in part on the assumption that groundwater acts as a linear reservoir, and so has a physical basis; it has only two adjustable parameters (alpha, obtained directly from recession analysis, and beta, the maximum value of the base-flow index that can be modeled by the filter), which can be determined objectively and with the same physical basis of groundwater reservoir linearity, or that can be optimized by applying a chemical-mass-balance constraint. Base-flow estimates from the recursive digital filter were compared with those from five other hydrograph-separation methods with respect to two metrics: the long-term average fraction of streamflow that is base flow, or base-flow index, and the fraction of days where streamflow is entirely base flow. There was generally good correlation between the methods, with some biased

Short-term variability of 7Be atmospheric deposition and watershed response in a Pacific coastal stream, Monterey Bay, California, USA

Science.gov (United States)

Conaway, Christopher H.; Storlazzi, Curt D.; Draut, Amy E.; Swarzenski, Peter W.

2013-01-01

Beryllium-7 is a powerful and commonly used tracer for environmental processes such as watershed sediment provenance, soil erosion, fluvial and nearshore sediment cycling, and atmospheric fallout. However, few studies have quantified temporal or spatial variability of 7Be accumulation from atmospheric fallout, and parameters that would better define the uses and limitations of this geochemical tracer. We investigated the abundance and variability of 7Be in atmospheric deposition in both rain events and dry periods, and in stream surface-water samples collected over a ten-month interval at sites near northern Monterey Bay (37°N, 122°W) on the central California coast, a region characterized by a rainy winters, dry summers, and small mountainous streams with flashy hydrology. The range of 7Be activity in rainwater samples from the main sampling site was 1.3–4.4 Bq L−1, with a mean (±standard deviation) of 2.2 ± 0.9 Bq L−1, and a volume-weighted average of 2.0 Bq L−1. The range of wet atmospheric deposition was 18–188 Bq m−2 per rain event, with a mean of 72 ± 53 Bq m−2. Dry deposition fluxes of 7Be ranged from less than 0.01 up to 0.45 Bq m−2 d−1, with an estimated dry season deposition of 7 Bq m−2 month−1. Annualized 7Be atmospheric deposition was approximately 1900 Bq m−2 yr−1, with most deposition via rainwater (>95%) and little via dry deposition. Overall, these activities and deposition fluxes are similar to values found in other coastal locations with comparable latitude and Mediterranean-type climate. Particulate 7Be values in the surface water of the San Lorenzo River in Santa Cruz, California, ranged from −1 to 0.6 Bq g−1, with a median activity of 0.26 Bq g−1. A large storm event in January 2010 characterized by prolonged flooding resulted in the entrainment of 7Be-depleted sediment, presumably from substantial erosion in the watershed. There were too few particulate 7Be data over the storm to accurately model a 7Be load

Hyperspectral remote sensing and long term monitoring reveal watershed-estuary ecosystem interactions

Science.gov (United States)

Hestir, E. L.; Schoellhamer, D. H.; Santos, M. J.; Greenberg, J. A.; Morgan-King, T.; Khanna, S.; Ustin, S.

2016-02-01

Estuarine ecosystems and their biogeochemical processes are extremely vulnerable to climate and environmental changes, and are threatened by sea level rise and upstream activities such as land use/land cover and hydrological changes. Despite the recognized threat to estuaries, most aspects of how change will affect estuaries are not well understood due to the poorly resolved understanding of the complex physical, chemical and biological processes and their interactions in estuarine systems. Remote sensing technologies such as high spectral resolution optical systems enable measurements of key environmental parameters needed to establish baseline conditions and improve modeling efforts. The San Francisco Bay-Delta is a highly modified estuary system in a state of ecological crisis due to the numerous threats to its sustainability. In this study, we used a combination of hyperspectral remote sensing and long-term in situ monitoring records to investigate how water clarity has been responding to extreme climatic events, anthropogenic watershed disturbances, and submerged aquatic vegetation (SAV) invasions. From the long-term turbidity monitoring record, we found that water clarity underwent significant increasing step changes associated with sediment depletion and El Nino-extreme run-off events. Hyperspectral remote sensing data revealed that invasive submerged aquatic pant species have facultative C3 and C4-like photosynthetic pathways that give them a competitive advantage under the changing water clarity conditions of the Bay-Delta system. We postulate that this adaptation facilitated the rapid expansion of SAV following the significant step changes in increasing water clarity caused by watershed disturbances and the 1982-1983 El Nino events. Using SAV maps from hyperspectral remote sensing, we estimate that SAV-water clarity feedbacks were responsible for 20-70% of the increasing water clarity trend in the Bay-Delta. Ongoing and future developments in airborne and

Nitrogen Saturation in Highly Retentive Watersheds?

Science.gov (United States)

Daley, M. L.; McDowell, W. H.

2009-12-01

Watershed managers are often concerned with minimizing the amount of N delivered to N-limited estuaries and coastal zones. A major concern is that watersheds might reach N saturation, in which N delivered to coastal zones increases due to declines in the efficiency of N retention despite constant or even reduced N inputs. We have quantified long-term changes in N inputs (atmospheric deposition, imported food and agricultural fertilizers), outputs (N concentration and export) and retention in the urbanizing Lamprey River watershed in coastal NH. Overall, the Lamprey watershed is 70% forested, receives about 13.5 kg N/ha/yr and has a high rate of annual N retention (85%). Atmospheric deposition (8.7 kg/ha/yr) is the largest N input to the watershed. Of the 2.2 kg N/ha/yr exported in the Lamprey River, dissolved organic N (DON) is the dominant form (50% of total) and it varies spatially throughout the watershed with wetland cover. Nitrate accounts for 30% of the N exported, shows a statistically significant increase from 1999 to 2009, and its spatial variability in both concentration and export is related to human population density. In sub-basins throughout the Lamprey, inorganic N retention is high (85-99%), but the efficiency of N retention declines sharply with increased human population density and associated anthropogenic N inputs. N assimilation in the vegetation, denitrification to the atmosphere and storage in the groundwater pool could all be important contributors to the current high rates of N retention. The temporal and spatial patterns that we have observed in nitrate concentration and export are driven by increases in N inputs and impervious surfaces over time, but the declining efficiency of N retention suggests that the watershed may also be reaching N saturation. The downstream receiving estuary, Great Bay, already suffers from low dissolved oxygen levels and eelgrass loss in part due to N loading from the Lamprey watershed. Targeting and reducing

A Review of Use of GIS for the Evaluation of Heavy Metal and Water Quality Parameters in the Canal do Cunha Watershed and west of the Guanabara Bay, Rio de Janeiro (Brazil

Directory of Open Access Journals (Sweden)

Renata Coura Borges

2016-06-01

Full Text Available As well as other sub-basins of the Guanabara Bay, the Canal do Cunha watershed, located in the Rio de Janeiro city, has suffered severe environmental degradation since the 50s, due to accelerated urban-industrial development. The fluvial dynamics has changed by the deforestation, landfill constructions, drainage and vale occupation. Canal do Cunha deliver wastewaters and sediments at the western side of Guanabara Bay. Contribute to the environmental degradation and has direct influence on the water quality indexes and heavy metal contamination at the western side of Guanabara Bay. This study intends to evaluate, through geoprocessing techniques, the spatial distribution of Lead (Pb, Zinc (Zn, dissolved oxygen (DO and total phosphorus (total P concentrations and pH values, using data provided by six monitoring stations of the Instituto Estadual do Ambiente – INEA (State Environmental Institute. This work allows to observe the influence of weather conditions on Pb and Zn concentrations in superficial waters and surface sediments and the behavior of DO, pH and total P of superficial waters before and after the implementation of the remediation program: Programa de Despoluição da Baía de Guanabara (PDBG; Pollution Remediation Program of Guanabara Bay. Canal do Cunha flow has direct influence on the low quality indexes of water and contributes to the heavy metal contamination and environmental degradation of the western region of Guanabara Bay.

Analysis of streamflow distribution of non-point source nitrogen export from long-term urban-rural catchments to guide watershed management in the Chesapeake Bay watershed

Science.gov (United States)

Duncan, J. M.; Band, L. E.; Groffman, P.

2017-12-01

Discharge, land use, and watershed management practices (stream restoration and stormwater control measures) have been found to be important determinants of nitrogen (N) export to receiving waters. We used long-term water quality stations from the Baltimore Ecosystem Study Long-Term Ecological Research (BES LTER) Site to quantify nitrogen export across streamflow conditions at the small watershed scale. We calculated nitrate and total nitrogen fluxes using methodology that allows for changes over time; weighted regressions on time, discharge, and seasonality. Here we tested the hypotheses that a) while the largest N stream fluxes occur during storm events, there is not a clear relationship between N flux and discharge and b) N export patterns are aseasonal in developed watersheds where sources are larger and retention capacity is lower. The goal is to scale understanding from small watersheds to larger ones. Developing a better understanding of hydrologic controls on nitrogen export is essential for successful adaptive watershed management at societally meaningful spatial scales.

Biogeochemical and Hydrological Controls on Mercury and Methylmercury in First Order Coastal Plain Watersheds of the Chesapeake Bay

Science.gov (United States)

Heyes, A.; Gilmour, C. C.; Bell, J. T.; Butera, D.; McBurney, A. W.

2015-12-01

Over the past 7 years we made use of the long-term research site at the Smithsonian Environmental Research Center (SERC) in central Maryland to study the fluxes of mercury (Hg) and methylmercury (MeHg) in three small first-order mid-Atlantic coastal plain watersheds. One watershed is entirely forested, one watershed is primarily agriculture with a forested stream buffer, and one watershed is mixed land use but contains a beaver produced wetland pond. Our initial goals were to assess watershed Hg yields in the mid-Atlantic and to establish a baseline prior to implementation of Hg emissions controls. All three studied watersheds produced relatively high yields of Hg, with the greatest yield coming from the forested watershed. Our initial evaluation of three watersheds showed that MeHg production and flux could also be high, but varied dramatically among watersheds and across years and seasons. During each year we observed episodic MeHg production in the spring and sometimes during prolonged high-flow storm events in the fall. The observed spring maxima of MeHg release coincided with development of anoxia in riparian groundwater. MeHg accumulation in riparian groundwater began once nitrate was depleted and either iron accumulation or sulfate depletion of groundwater began. We propose the presence of nitrate was modulating MeHg production through the suppression of sulfate and iron reducers and perhaps methanogens. As sulfate is not limiting in any of the watersheds owing to the sediments marine origin, we hypothesize the depletion of nitrate allows sulfate reducing bacteria to now utilize available carbon. Although wetlands are generally thought of as the primary zones of MeHg production in watersheds, shallow riparian groundwaters very close to the stream appear to play that role in SERC Coastal Plain watersheds. We hypothesize that the balance between nitrate, sulfate and other microbial electron acceptors in watersheds is a major control on MeHg production. Land

Combined and synergistic effects of climate change and urbanization on water quality in the Wolf Bay watershed, southern Alabama.

Science.gov (United States)

Wang, Ruoyu; Kalin, Latif

2018-02-01

This study investigated potential changes in flow, total suspended solid (TSS) and nutrient (nitrogen and phosphorous) loadings under future climate change, land use/cover (LULC) change and combined change scenarios in the Wolf Bay watershed, southern Alabama, USA. Four Global Circulation Models (GCMs) under three Special Report Emission Scenarios (SRES) of greenhouse gas were used to assess the future climate change (2016-2040). Three projected LULC maps (2030) were employed to reflect different extents of urbanization in future. The individual, combined and synergistic impacts of LULC and climate change on water quantity/quality were analyzed by the Soil and Water Assessment Tool (SWAT). Under the "climate change only" scenario, monthly distribution and projected variation of TSS are expected to follow a pattern similar to streamflow. Nutrients are influenced both by flow and management practices. The variation of Total Nitrogen (TN) and Total Phosphorous (TP) generally follow the flow trend as well. No evident difference in the N:P ratio was projected. Under the "LULC change only" scenario, TN was projected to decrease, mainly due to the shrinkage of croplands. TP will increase in fall and winter. The N:P ratio shows a strong decreasing potential. Under the "combined change" scenario, LULC and climate change effect were considered simultaneously. Results indicate that if future loadings are expected to increase/decrease under any individual scenario, then the combined change will intensify that trend. Conversely, if their effects are in opposite directions, an offsetting effect occurs. Science-based management practices are needed to reduce nutrient loadings to the Bay. Copyright © 2017. Published by Elsevier B.V.

Intra- and inter-annual trends in phosphorus loads and comparison with nitrogen loads to Rehoboth Bay, Delaware (USA)

Science.gov (United States)

Volk, J.A.; Scudlark, J.R.; Savidge, K.B.; Andres, A.S.; Stenger, R.J.; Ullman, W.J.

2012-01-01

Monthly phosphorus loads from uplands, atmospheric deposition, and wastewater to Rehoboth Bay (Delaware) were determined from October 1998 to April 2002 to evaluate the relative importance of these three sources of P to the Bay. Loads from a representative subwatershed were determined and used in an areal extrapolation to estimate the upland load from the entire watershed. Soluble reactive phosphorus (SRP) and dissolved organic P (DOP) are the predominant forms of P in baseflow and P loads from the watershed are highest during the summer months. Particulate phosphorus (PP) becomes more significant in stormflow and during periods with more frequent or larger storms. Atmospheric deposition of P is only a minor source of P to Rehoboth Bay. During the period of 1998-2002, wastewater was the dominant external source of P to Rehoboth Bay, often exceeding all other P sources combined. Since 2002, however, due to technical improvements to the sole wastewater plant discharging directly to the Bay, the wastewater contribution of P has been significantly reduced and upland waters are now the principal source of P on an annualized basis. Based on comparison of N and P loads, primary productivity and biomass carrying capacity in Rehoboth Bay should be limited by P availability. However, due to the contrasting spatial and temporal patterns of N and P loading and perhaps internal cycling within the ecosystem, spatial and temporal variations in N and P-limitation within Rehoboth Bay are likely. ?? 2011 Elsevier Ltd.

Watershed characterization and analysis using the VELMA ...

Science.gov (United States)

We developed a broadly applicable watershed simulator – VELMA (Visualizing Ecosystem and Land Management Assessments) – to characterize hydrological and ecological processes essential to the healthy functioning of watersheds, and to identify best management practices (BMPs) for restoring ecosystem services such as provisioning of clean water, food and fiber, and habitat for fish and wildlife. VELMA has been applied to agricultural, forest, rangeland and arctic watersheds across North America. Urban applications are under development. This seminar will discuss how VELMA is being used to help inform (1) salmon recovery planning in Puget Sound, and (2) water quality protection in Chesapeake Bay agricultural landscapes. These examples highlight the importance of model validation; how VELMA is being linked with additional models to aid BMP identification; and how the model is being transferred to community groups, tribes, and state and federal agencies engaged in environmental decision making. This invited seminar for the Washington State Department of Ecology will provide an overview of EPA’s VELMA watershed simulator and its applications for identifying best management practices for protecting and restoring vital ecosystem services, such as provisioning of clean water, food and fiber, and habitat for fish and wildlife. After the seminar, the presenter will meet with Department of Ecology staff to discuss the feasibility of including VELMA in their Puget Sound

Summary and Synthesis of Mercury Studies in the Cache Creek Watershed, California, 2000-01

Science.gov (United States)

Domagalski, Joseph L.; Slotton, Darell G.; Alpers, Charles N.; Suchanek, Thomas H.; Churchill, Ronald; Bloom, Nicolas; Ayers, Shaun M.; Clinkenbeard, John

2004-01-01

This report summarizes the principal findings of the Cache Creek, California, components of a project funded by the CALFED Bay?Delta Program entitled 'An Assessment of Ecological and Human Health Impacts of Mercury in the Bay?Delta Watershed.' A companion report summarizes the key findings of other components of the project based in the San Francisco Bay and the Delta of the Sacramento and San Joaquin Rivers. These summary documents present the more important findings of the various studies in a format intended for a wide audience. For more in-depth, scientific presentation and discussion of the research, a series of detailed technical reports of the integrated mercury studies is available at the following website: .

Short-term variability of 7Be atmospheric deposition and watershed response in a Pacific coastal stream, Monterey Bay, California, USA

International Nuclear Information System (INIS)

Conaway, Christopher H.; Storlazzi, Curt D.; Draut, Amy E.; Swarzenski, Peter W.

2013-01-01

Beryllium-7 is a powerful and commonly used tracer for environmental processes such as watershed sediment provenance, soil erosion, fluvial and nearshore sediment cycling, and atmospheric fallout. However, few studies have quantified temporal or spatial variability of 7 Be accumulation from atmospheric fallout, and parameters that would better define the uses and limitations of this geochemical tracer. We investigated the abundance and variability of 7 Be in atmospheric deposition in both rain events and dry periods, and in stream surface-water samples collected over a ten-month interval at sites near northern Monterey Bay (37°N, 122°W) on the central California coast, a region characterized by a rainy winters, dry summers, and small mountainous streams with flashy hydrology. The range of 7 Be activity in rainwater samples from the main sampling site was 1.3–4.4 Bq L −1 , with a mean (±standard deviation) of 2.2 ± 0.9 Bq L −1 , and a volume-weighted average of 2.0 Bq L −1 . The range of wet atmospheric deposition was 18–188 Bq m −2 per rain event, with a mean of 72 ± 53 Bq m −2 . Dry deposition fluxes of 7 Be ranged from less than 0.01 up to 0.45 Bq m −2 d −1 , with an estimated dry season deposition of 7 Bq m −2 month −1 . Annualized 7 Be atmospheric deposition was approximately 1900 Bq m −2 yr −1 , with most deposition via rainwater (>95%) and little via dry deposition. Overall, these activities and deposition fluxes are similar to values found in other coastal locations with comparable latitude and Mediterranean-type climate. Particulate 7 Be values in the surface water of the San Lorenzo River in Santa Cruz, California, ranged from −1 to 0.6 Bq g −1 , with a median activity of 0.26 Bq g −1 . A large storm event in January 2010 characterized by prolonged flooding resulted in the entrainment of 7 Be-depleted sediment, presumably from substantial erosion in the watershed. There were too few particulate 7 Be data over the storm

Integrating terrestrial LiDAR and stereo photogrammetry to map the Tolay lakebed in northern San Francisco Bay

Science.gov (United States)

Woo, Isa; Storesund,; Takekawa, John Y.; Gardiner, Rachel J.; Ehret,

2009-01-01

The Tolay Creek Watershed drains approximately 3,520 ha along the northern edge of San Francisco Bay. Surrounded by a mosaic of open space conservation easements and public wildlife areas, it is one of the only watersheds in this urbanized estuary that is protected from its headwaters to the bay. Tolay Lake is a seasonal, spring-fed lake found in the upper watershed that historically extended over 120 ha. Although the lakebed was farmed since the early 1860s, the majority of the lakebed was recently acquired by the Sonoma County Regional Parks Department to restore its natural habitat values. As part of the restoration planning process, we produced a digital elevation model (DEM) of the historic extent of Tolay Lake by integrating terrestrial LiDAR (light detection and ranging) and stereo photogrammetry datasets, and real-time kinematic (RTK) global positioning system (GPS) surveys. We integrated the data, generated a DEM of the lakebed and upland areas, and analyzed errors. The accuracy of the composite DEM was verified using spot elevations obtained from the RTK GPS. Thus, we found that by combining photogrammetry, terrestrial LiDAR, and RTK GPS, we created an accurate baseline elevation map to use in watershed restoration planning and design.

Hydrogeological impacts of road salt from Canada's busiest highway on a Lake Ontario watershed (Frenchman's Bay) and lagoon, City of Pickering.

Science.gov (United States)

Meriano, Mandana; Eyles, Nick; Howard, Ken W F

2009-06-26

The quantity of deicing salt applied to paved surfaces in urban watersheds in cold regions has had a significant and cumulative effect on groundwater quality. Whereas road deicing salt is known in general to impact groundwater and surface water quality, quantitative information on the impact of large transport routes is lacking. In this study, we provide a chloride mass balance for an urban stream crossed by a large transport route in south-central Ontario, Canada and quantify likely long-term impacts of salt loading on surface and groundwater resources. The chloride mass balance, supported by hydrochemical analysis, reveals that approximately 50% of the total road salt applied to Pine Creek (1700 tonnes per winter) is removed annually via overland flow with the remainder accumulating in the shallow subsurface resulting in severe degradation of groundwater quality. Moreover, results show that road salt migration is the primary reason for enhanced mineral weathering in the shallow aquifer. During the 2004-05 salting season, runoff and baseflow transport of road salts were responsible for chloride concentrations in the stream of up to 2000 mg L(-1), and delivered approximately 850 tonnes of chloride (about 1400 tonnes of salt) to a shallow (<3.5 m) semi-enclosed lagoon on the shore of Lake Ontario (Frenchman's Bay; 0.85 km(2)). The total chloride delivery to the lagoon from its entire watershed is estimated at 3700 tonnes each year with up to 48% of the total load delivered by baseflow, the remainder from surface water runoff. Present day groundwater chloride concentrations are estimated to be about 80% of long-term concentrations when the system reaches steady state.

Hydrogeological impacts of road salt from Canada's busiest highway on a Lake Ontario watershed (Frenchman's Bay) and lagoon, City of Pickering

Science.gov (United States)

Meriano, Mandana; Eyles, Nick; Howard, Ken W. F.

2009-06-01

The quantity of deicing salt applied to paved surfaces in urban watersheds in cold regions has had a significant and cumulative effect on groundwater quality. Whereas road deicing salt is known in general to impact groundwater and surface water quality, quantitative information on the impact of large transport routes is lacking. In this study, we provide a chloride mass balance for an urban stream crossed by a large transport route in south-central Ontario, Canada and quantify likely long-term impacts of salt loading on surface and groundwater resources. The chloride mass balance, supported by hydrochemical analysis, reveals that approximately 50% of the total road salt applied to Pine Creek (1700 tonnes per winter) is removed annually via overland flow with the remainder accumulating in the shallow subsurface resulting in severe degradation of groundwater quality. Moreover, results show that road salt migration is the primary reason for enhanced mineral weathering in the shallow aquifer. During the 2004-05 salting season, runoff and baseflow transport of road salts were responsible for chloride concentrations in the stream of up to 2000 mg L - 1 , and delivered approximately 850 tonnes of chloride (about 1400 tonnes of salt) to a shallow (< 3.5 m) semi-enclosed lagoon on the shore of Lake Ontario (Frenchman's Bay; 0.85 km 2). The total chloride delivery to the lagoon from its entire watershed is estimated at 3700 tonnes each year with up to 48% of the total load delivered by baseflow, the remainder from surface water runoff. Present day groundwater chloride concentrations are estimated to be about 80% of long-term concentrations when the system reaches steady state.

Hydrological functions of a mine-impacted and natural peatland-dominated watershed, James Bay Lowland

Directory of Open Access Journals (Sweden)

Melissa Leclair

2015-09-01

New hydrological insights: Deep seepage (groundwater recharge varied with marine sediment thickness and represented a significant loss to the local system. Large downward fluxes were also measured in fen systems that are typically local discharge zones. Evaporation rates were also found to be lower in the bogs and fens and where impacted by lower water tables. When evaluating the water balance, with only 14.5% of the watershed impacted by the mine, the hydrological function of the entire watershed is more driven by seasonal climate variations than mine dewatering.

The simulated effects of wastewater-management actions on the hydrologic system and nitrogen-loading rates to wells and ecological receptors, Popponesset Bay Watershed, Cape Cod, Massachusetts

Science.gov (United States)

Walter, Donald A.

2013-01-01

The discharge of excess nitrogen into Popponesset Bay, an estuarine system on western Cape Cod, has resulted in eutrophication and the loss of eel grass habitat within the estuaries. Septic-system return flow in residential areas within the watershed is the primary source of nitrogen. Total Maximum Daily Loads (TMDLs) for nitrogen have been assigned to the six estuaries that compose the system, and local communities are in the process of implementing the TMDLs by the partial sewering, treatment, and disposal of treated wastewater at wastewater-treatment facilities (WTFs). Loads of waste-derived nitrogen from both current (1997–2001) and future sources can be estimated implicitly from parcel-scale water-use data and recharge areas delineated by a groundwater-flow model. These loads are referred to as “instantaneous” loads because it is assumed that the nitrogen from surface sources is delivered to receptors instantaneously and that there is no traveltime through the aquifer. The use of a solute-transport model to explicitly simulate the transport of mass through the aquifer from sources to receptors can improve implementation of TMDLs by (1) accounting for traveltime through the aquifer, (2) avoiding limitations associated with the estimation of loads from static recharge areas, (3) accounting more accurately for the effect of surface waters on nitrogen loads, and (4) determining the response of waste-derived nitrogen loads to potential wastewater-management actions. The load of nitrogen to Popponesset Bay on western Cape Cod, which was estimated by using current sources as input to a solute-transport model based on a steady-state flow model, is about 50 percent of the instantaneous load after about 7 years of transport (loads to estuary are equal to loads discharged from sources); this estimate is consistent with simulated advective traveltimes in the aquifer, which have a median of 5 years. Model-calculated loads originating from recharge areas reach 80

USGS Tampa Bay Pilot Study

Science.gov (United States)

Yates, K.K.; Cronin, T. M.; Crane, M.; Hansen, M.; Nayeghandi, A.; Swarzenski, P.; Edgar, T.; Brooks, G.R.; Suthard, B.; Hine, A.; Locker, S.; Willard, D.A.; Hastings, D.; Flower, B.; Hollander, D.; Larson, R.A.; Smith, K.

2007-01-01

Many of the nation's estuaries have been environmentally stressed since the turn of the 20th century and will continue to be impacted in the future. Tampa Bay, one the Gulf of Mexico's largest estuaries, exemplifies the threats that our estuaries face (EPA Report 2001, Tampa Bay Estuary Program-Comprehensive Conservation and Management Plan (TBEP-CCMP)). More than 2 million people live in the Tampa Bay watershed, and the population constitutes to grow. Demand for freshwater resources, conversion of undeveloped areas to resident and industrial uses, increases in storm-water runoff, and increased air pollution from urban and industrial sources are some of the known human activities that impact Tampa Bay. Beginning on 2001, additional anthropogenic modifications began in Tampa Bat including construction of an underwater gas pipeline and a desalinization plant, expansion of existing ports, and increased freshwater withdrawal from three major tributaries to the bay. In January of 2001, the Tampa Bay Estuary Program (TBEP) and its partners identifies a critical need for participation from the U.S. Geological Survey (USGS) in providing multidisciplinary expertise and a regional-scale, integrated science approach to address complex scientific research issue and critical scientific information gaps that are necessary for continued restoration and preservation of Tampa Bay. Tampa Bay stakeholders identified several critical science gaps for which USGS expertise was needed (Yates et al. 2001). These critical science gaps fall under four topical categories (or system components): 1) water and sediment quality, 2) hydrodynamics, 3) geology and geomorphology, and 4) ecosystem structure and function. Scientists and resource managers participating in Tampa Bay studies recognize that it is no longer sufficient to simply examine each of these estuarine system components individually, Rather, the interrelation among system components must be understood to develop conceptual and

Use of Nutrient Balances in Comprehensive Watershed Water Quality Modeling of Chesapeake Bay

National Research Council Canada - National Science Library

Donigian, Anthony

1998-01-01

... state of-the-art watershed modeling capability that includes detailed soil process simulation for agricultural areas, linked to an instream water quality and nutrient model capable of representing...

Rate of Loaded Sediments in Honda Bay, Puerto Princesa City, Palawan, Philippines

Directory of Open Access Journals (Sweden)

Joel Becira

2006-06-01

Full Text Available A study in Honda Bay, Puerto Princesa City, Palawan, Philippines was conducted to determine and compare the rate of loaded sediments of and among six sites in Honda Bay and during two seasons, and to discuss sedimentation rate in relation to selected environmental parameters commencing on April 2003 to November 2003.Results showed that the Babuyan River significantly contributed to the amounts of sediments being loaded to Honda Bay, Puerto Princesa City of which the amount of sediments loaded between the two sampling season and among the six sampling events had no significant difference. Sediment's color and texture affirmed the land-based activities in Babuyan and Mauyon watersheds, which eventually carried into the Bay during storm weather condition.The amount of trapped sediments in all stations is probably affected by the river's discharge capacity and the river's water velocity, although the duration sediment traps were mounted could also affect the measurement of sedimentation rate.

Modeling drivers of phosphorus loads in Chesapeake Bay tributaries and inferences about long-term change

Science.gov (United States)

Ryberg, Karen R.; Blomquist, Joel; Sprague, Lori A.; Sekellick, Andrew J.; Keisman, Jennifer

2018-01-01

Causal attribution of changes in water quality often consists of correlation, qualitative reasoning, listing references to the work of others, or speculation. To better support statements of attribution for water-quality trends, structural equation modeling was used to model the causal factors of total phosphorus loads in the Chesapeake Bay watershed. By transforming, scaling, and standardizing variables, grouping similar sites, grouping some causal factors into latent variable models, and using methods that correct for assumption violations, we developed a structural equation model to show how causal factors interact to produce total phosphorus loads. Climate (in the form of annual total precipitation and the Palmer Hydrologic Drought Index) and anthropogenic inputs are the major drivers of total phosphorus load in the Chesapeake Bay watershed. Increasing runoff due to natural climate variability is offsetting purposeful management actions that are otherwise decreasing phosphorus loading; consequently, management actions may need to be reexamined to achieve target reductions in the face of climate variability.

Atmospheric Nitrogen Deposition Loadings to the Chesapeake Bay: An Initial Analysis of the Cost Effectiveness of Control Options (1996)

Science.gov (United States)

This report examines the cost effectiveness of control options which reduce nitrate deposition to the Chesapeake watershed and to the tidal Bay. The report analyzes current estimates of the reductions expected in the ozone transport region.

Use of Land Use Land Cover Change Mapping Products in Aiding Coastal Habitat Conservation and Restoration Efforts of the Mobile Bay NEP

Science.gov (United States)

Spruce, Joseph P.; Swann, Roberta; Smooth, James

2010-01-01

The Mobile Bay region has undergone significant land use land cover change (LULC) over the last 35 years, much of which is associated with urbanization. These changes have impacted the region s water quality and wildlife habitat availability. In addition, much of the region is low-lying and close to the Gulf, which makes the region vulnerable to hurricanes, climate change (e.g., sea level rise), and sometimes man-made disasters such as the Deepwater Horizon (DWH) oil spill. Land use land cover change information is needed to help coastal zone managers and planners to understand and mitigate the impacts of environmental change on the region. This presentation discusses selective results of a current NASA-funded project in which Landsat data over a 34-year period (1974-2008) is used to produce, validate, refine, and apply land use land cover change products to aid coastal habitat conservation and restoration needs of the Mobile Bay National Estuary Program (MB NEP). The project employed a user defined classification scheme to compute LULC change mapping products for the entire region, which includes the majority of Mobile and Baldwin counties. Additional LULC change products have been computed for select coastal HUC-12 sub-watersheds adjacent to either Mobile Bay or the Gulf of Mexico, as part of the MB NEP watershed profile assessments. This presentation will include results of additional analyses of LULC change for sub-watersheds that are currently high priority areas, as defined by MB NEP. Such priority sub-watersheds include those that are vulnerable to impacts from the DWH oil spill, as well as sub-watersheds undergoing urbanization. Results demonstrating the nature and permanence of LULC change trends for these higher priority sub-watersheds and results characterizing change for the entire 34-year period and at approximate 10-year intervals across this period will also be presented. Future work will include development of value-added coastal habitat quality

Coastal circulation and sediment dynamics in Maunalua Bay, Oahu, Hawaii, measurements of waves, currents, temperature, salinity, and turbidity; November 2008-February 2009

Science.gov (United States)

Storlazzi, Curt D.; Presto, M. Katherine; Logan, Joshua B.; Field, Michael E.

2010-01-01

High-resolution measurements of waves, currents, water levels, temperature, salinity and turbidity were made in Maunalua Bay, southern Oahu, Hawaii, during the 2008-2009 winter to better understand coastal circulation, water-column properties, and sediment dynamics during a range of conditions (trade winds, kona storms, relaxation of trade winds, and south swells). A series of bottom-mounted instrument packages were deployed in water depths of 20 m or less to collect long-term, high-resolution measurements of waves, currents, water levels, temperature, salinity, and turbidity. These data were supplemented with a series of profiles through the water column to characterize the vertical and spatial variability in water-column properties within the bay. These measurements support the ongoing process studies being done as part of the U.S. Geological Survey (USGS) Coastal and Marine Geology Program's Pacific Coral Reef Project; the ultimate goal of these studies is to better understand the transport mechanisms of sediment, larvae, pollutants, and other particles in coral reef settings. Project Objectives The objective of this study was to understand the temporal variations in currents, waves, tides, temperature, salinity and turbidity within a coral-lined embayment that receives periodic discharges of freshwater and sediment from multiple terrestrial sources in the Maunalua Bay. Instrument packages were deployed for a three-month period during the 2008-2009 winter and a series of vertical profiles were collected in November 2008, and again in February 2009, to characterize water-column properties within the bay. Measurements of flow and water-column properties in Maunalua Bay provided insight into the potential fate of terrestrial sediment, nutrient, or contaminant delivered to the marine environment and coral larval transport within the embayment. Such data are useful for providing baseline information for future watershed decisions and for establishing guidelines for

Comparative analysis of long-term chlorophyll data with generalized additive model - San Francisco Bay and St. Lucie Estuary

Science.gov (United States)

The health of estuarine ecosystems is often influenced by hydraulic and nutrient loading from upstream watersheds. We examined four decades of monitoring data of nutrient export into the Indian River Lagoon and San Francisco Bay, both of which have received considerable attentio...

Linking Ecosystem Services Supply to Stakeholder Values in Guanica Bay Watershed, Puerto Rico

Science.gov (United States)

Policies to protect coastal resources will be more effective when they account for the social and economic concerns of stakeholders in the coastal zone and watershed, and are responsive to potential tradeoffs between benefits offered by both land and sea. We focus on the Gu&aacu...

Tampa Bay as a model estuary for examining the impact of human activities on biogeochemical processes: an introduction

Science.gov (United States)

Swarzenski, Peter W.; Baskaran, Mark; Henderson, Carl S.; Yates, Kim

2007-01-01

Tampa Bay is a shallow, Y-shaped coastal embayment that is located along the center of the Florida Platform – an expansive accumulation of Cretaceous–Tertiary shallow-water carbonates and evaporites that were periodically exposed during glacio–eustatic sea level fluctuations. As a consequence, extensive karstification likely had a controlling impact on the geologic evolution of Tampa Bay. Despite its large aerial size (∼ 1000 km2), Tampa Bay is relatively shallow (mean depth = 4 m) and its watershed (6700 km2) is among the smallest in the Gulf of Mexico. About 85% of all freshwater inflow (mean = 63 m3 s-1) to the bay is carried by four principal tributaries (Orlando et al., 1993). Groundwater makes up an important component of baseflow of these coastal streams and may also be important in delivering nutrients and other constituents to the bay proper by submarine groundwater discharge.

Development of an integrated ecosystem model to determine effectiveness of potential watershed management projects on improving Old Tampa Bay

Science.gov (United States)

Edward T. Sherwood; Holly Greening; Lizanne Garcia; Kris Kaufman; Tony Janicki; Ray Pribble; Brett Cunningham; Steve Peene; Jim Fitzpatrick; Kellie Dixon; Mike Wessel

2016-01-01

The Tampa Bay estuary has undergone a remarkable ecosystem recovery since the 1980s despite continued population growth within the region. However during this time, the Old Tampa Bay (OTB) segment has lagged behind the rest of the Bay’s recovery relative to improvements in overall water quality and seagrass coverage. In 2011, the Tampa Bay Estuary Program, in...

Minnesota Watersheds

Data.gov (United States)

Minnesota Department of Natural Resources — Statewide minor watershed delineations with major/minor watershed identifiers and names for provinces, major watersheds, and basins. Also included are watershed...

Reducing Nutrients and Nutrient Impacts Priority Issue Team - St. Louis Bay Project: Implementing Nutrients PIT Action Step 1.1

Science.gov (United States)

Mason, Ted

2011-01-01

The NASA Applied Science & Technology Project Office at Stennis Space Center(SSC) used satellites, in-situ measurements and computational modeling to study relationships between water quality in St. Louis Bay, Mississippi and the watershed characteristics of the Jourdan and Wolf rivers from 2000-2010.

Hydrology, phosphorus, and suspended solids in five agricultural streams in the Lower Fox River and Green Bay Watersheds, Wisconsin, Water Years 2004-06

Science.gov (United States)

Graczyk, David J.; Robertson, Dale M.; Baumgart, Paul D.; Fermanich, Kevin J.

2011-01-01

A 3-year study was conducted by the U.S. Geological Survey and the University of Wisconsin-Green Bay to characterize water quality in agricultural streams in the Fox/Wolf watershed in northeastern Wisconsin and provide information to assist in the calibration of a watershed model for the area. Streamflow, phosphorus, and suspended solids data were collected between October 1, 2003, and September 30, 2006, in five streams, including Apple Creek, Ashwaubenon Creek, Baird Creek, Duck Creek, and the East River. During this study, total annual precipitation was close to the 30-year normal of 29.12 inches. The 3-year mean streamflow was highest in the East River (113 ft3/s), followed by Duck Creek (58.2 ft3/s), Apple Creek (26.9 ft3/s), Baird Creek (12.8 ft3/s), and Ashwaubenon Creek (9.1 ft3/s). On a yield basis, during these three years, the East River had the highest flow (0.78 ft3/s/mi2), followed by Baird Creek (0.61 ft3/s/mi2), Apple Creek (0.59 ft3/s/mi2), Duck Creek (0.54 ft3/s/mi2), and Ashwaubenon Creek (0.46 ft3/s/mi2). The overall median total suspended solids (TSS) concentration was highest in Baird Creek (73.5 mg/L), followed by Apple and Ashwaubenon Creeks (65 mg/L), East River (40 mg/L), and Duck Creek (30 mg/L). The median total phosphorus (TP) concentration was highest in Ashwaubenon Creek (0.60 mg/L), followed by Baird Creek (0.47 mg/L), Apple Creek (0.37 mg/L), East River (0.26 mg/L), and Duck Creek (0.22 mg/L).

Shifting shoals and shattered rocks : How man has transformed the floor of west-central San Francisco Bay

Science.gov (United States)

Chin, John L.; Wong, Florence L.; Carlson, Paul R.

2004-01-01

San Francisco Bay, one of the world's finest natural harbors and a major center for maritime trade, is referred to as the 'Gateway to the Pacific Rim.' The bay is an urbanized estuary that is considered by many to be the major estuary in the United States most modified by man's activities. The population around the estuary has grown rapidly since the 1850's and now exceeds 7 million people. The San Francisco Bay area's economy ranks as one of the largest in the world, larger even than that of many countries. More than 10 million tourists are estimated to visit the bay region each year. The bay area's population and associated development have increasingly changed the estuary and its environment. San Francisco Bay and the contiguous Sacramento-San Joaquin Delta encompass roughly 1,600 square miles (4,100 km2) and are the outlet of a major watershed that drains more than 40 percent of the land area of the State of California. This watershed provides drinking water for 20 million people (two thirds of the State's population) and irrigates 4.5 million acres of farmland and ranchland. During the past several decades, much has been done to clean up the environment and waters of San Francisco Bay. Conservationist groups have even bought many areas on the margins of the bay with the intention of restoring them to a condition more like the natural marshes they once were. However, many of the major manmade changes to the bay's environment occurred so long ago that the nature of them has been forgotten. In addition, many changes continue to occur today, such as the introduction of exotic species and the loss of commercial and sport fisheries because of declining fish populations. The economy and population of the nine counties that surround the bay continue to grow and put increasing pressure on the bay, both direct and indirect. Therefore, there are mixed signals for the future health and welfare of San Francisco Bay. The San Francisco Bay estuary consists of three

Sediment transport in the San Francisco Bay Coastal System: An overview

Science.gov (United States)

Barnard, Patrick L.; Schoellhamer, David H.; Jaffe, Bruce E.; Lester J. McKee,

2013-01-01

The papers in this special issue feature state-of-the-art approaches to understanding the physical processes related to sediment transport and geomorphology of complex coastal-estuarine systems. Here we focus on the San Francisco Bay Coastal System, extending from the lower San Joaquin-Sacramento Delta, through the Bay, and along the adjacent outer Pacific Coast. San Francisco Bay is an urbanized estuary that is impacted by numerous anthropogenic activities common to many large estuaries, including a mining legacy, channel dredging, aggregate mining, reservoirs, freshwater diversion, watershed modifications, urban run-off, ship traffic, exotic species introductions, land reclamation, and wetland restoration. The Golden Gate strait is the sole inlet connecting the Bay to the Pacific Ocean, and serves as the conduit for a tidal flow of ~ 8 x 109 m3/day, in addition to the transport of mud, sand, biogenic material, nutrients, and pollutants. Despite this physical, biological and chemical connection, resource management and prior research have often treated the Delta, Bay and adjacent ocean as separate entities, compartmentalized by artificial geographic or political boundaries. The body of work herein presents a comprehensive analysis of system-wide behavior, extending a rich heritage of sediment transport research that dates back to the groundbreaking hydraulic mining-impact research of G.K. Gilbert in the early 20th century.

Application of stable isotopes to the assessment of pollution loading from various sources in the Pampanga River system into the Manila Bay, Philippines

International Nuclear Information System (INIS)

2013-01-01

The study focuses on the Pampanga River Basin as prototype for the other watersheds of Manila Bay. The pollution of the Bay is associated to loading from agriculture, industry and services sectors but with no direct evidence, hence the origins of pollution have to be identified for area-based resource management actions. The multiple stable isotopes were used and applied in identifying and tracing through spectral signature the origin of nutrient loading

Chlorinated hydrocarbon pesticides and polychlorinated biphenyls in sediment cores from San Francisco Bay

Science.gov (United States)

Venkatesan, M.I.; De Leon, R. P.; VanGeen, A.; Luoma, S.N.

1999-01-01

Sediment cores of known chronology from Richardson and San Pablo Bays in San Francisco Bay, CA, were analyzed for a suite of chlorinated hydrocarbon pesticides and polychlorinated biphenyls to reconstruct a historic record of inputs. Total DDTs (DDT = 2,4'- and 4,4'-dichlorodiphenyltrichloroethane and the metabolites, 2,4'- and 4,4'-DDE, -DDD) range in concentration from 4-21 ng/g and constitute a major fraction (> 84%) of the total pesticides in the top 70 cm of Richardson Bay sediment. A subsurface maximum corresponds to a peak deposition date of 1969-1974. The first measurable DDT levels are found in sediment deposited in the late 1930's. The higher DDT inventory in the San Pablo relative to the Richardson Bay core probably reflects the greater proximity of San Pablo Bay to agricultural activities in the watershed of the Sacramento and San Joaquin rivers. Total polychlorinated biphenyls (PCBs) occur at comparable levels in the two Bays (inventories in San Pablo Bay are about a factor of four higher in the last four decades than in Richardson Bay, suggesting a distribution of inputs not as strongly weighed towards the upper reaches of the estuary as DDTs. The shallower subsurface maximum in PCBs compared to DDT in the San Pablo Bay core is consistent with the imposition of drastic source control measures four these constituents in 1970 and 1977 respectively. The observed decline in DDT and PCB levels towards the surface of both cores is consistent with a dramatic drop in the input of these pollutants once the effect of sediment resuspension and mixing is taken into account.

Using Stable Isotopes to Link Nutrient Sources in the Everglades and Biological Sinks in Florida Bay: A Biogeochemical Approach to Evaluate Ecosystem Response to Changing Nutrient Regimes

Science.gov (United States)

Hoare, A. M.; Hollander, D. J.; Heil, C.; Glibert, P.; Murasko, S.; Revilla, M.; Alexander, J.

2005-05-01

Anthropogenic influences in South Florida have led to deterioration of its two major ecosystems, the Everglades wetlands and the Florida Bay estuary. Consequently, the Comprehensive Everglades Restoration Plan has been proposed to restore the Everglades ecosystem; however, restoration efforts will likely exert new ecological changes in the Everglades and ultimately Florida Bay. The success of the Florida Everglades restoration depends on our understanding and ability to predict how regional changes in the distribution and composition of dissolved organic and inorganic nutrients will direct the downstream biogeochemical dynamics of Florida Bay. While the transport of freshwater and nutrients to Florida Bay have been studied, much work remains to directly link nutrient dynamics in Florida Bay to nutrient sources in the Everglades. Our study uses stable C and N isotopic measurements of chemical and biological materials from the Everglades and Florida Bay as part of a multi-proxy approach to link nutrient sources in the Everglades to biological sinks in Florida Bay. Isotopic analyses of dissolved and particulate species of water, aquatic vegetation and sedimentary organic matter show that the watersheds within the Everglades are chemically distinct and that these signatures are also reflected in the bay. A large east-west gradient in both carbon and nitrogen (as much as 10‰ for δ15N POM) reflect differing nutrient sources for each region of Florida Bay and is strongly correlated with upstream sources in the Everglades. Isotopic signatures also reflect seasonal relationships associated with wet and dry periods. High C and N measurements of DOM and POM measurements suggest significant influence from waste water in Canal C-111 in eastern Florida Bay, particularly during the dry season. These observations show that nutrients from the Everglades watersheds enter Florida Bay and are important in controlling biogeochemical processes in the bay. This study proves that

Atmospheric nitrogen inputs to the Delaware Inland Bays: the role of ammonia

International Nuclear Information System (INIS)

Scudlark, Joseph R.; Jennings, Jennifer A.; Roadman, Megan J.; Savidge, Karen B.; Ullman, William J.

2005-01-01

A previous assessment of nitrogen loading to the Delaware Inland Bays indicates that atmospheric deposition provides 15-25% of the total, annual N input to these estuaries. A large and increasing fraction of the atmospheric wet flux is NH 4 + , which for most aquatic organisms represents the most readily assimilated form of this nutrient. Particularly noteworthy is a 60% increase in the precipitation NH 4 + concentration at Lewes, DE over the past 20 years, which parallels the increase in poultry production on the Delmarva Peninsula over this period (currently standing at nearly 585 million birds annually). To further examine the relationship between local NH 3 emissions and deposition, biweekly-integrated gaseous NH 3 concentrations were determined using Ogawa passive samplers deployed at 13 sampling sites throughout the Inland Bays watershed over a one-year period. Annual mean concentrations at the 13 sites ranged from 3 m -3 to >6 μg NH 3 m -3 , with a mean of 1.6 ± 1.0 μg NH 3 m -3 . At most sites, highest NH 3 concentrations were evident during spring and summer, when fertilizer application and poultry house ventilation rates are greatest, and seasonally elevated temperatures induce increased rates of microbial activity and volatilization from soils and animal wastes. The observed north-to-south concentration gradient across the watershed is consistent with the spatial distribution of poultry houses, as revealed by a GIS analysis of aerial photographs. Based on the average measured NH 3 concentration and published NH 3 deposition rates to water surfaces (5-8 mm s -1 ), the direct atmospheric deposition of gaseous NH 3 to the Inland Bays is 3.0-4.8 kg ha -1 yr -1 . This input, not accounted for in previous assessments of atmospheric loading to the Inland Bays, would effectively double the estimated direct dry deposition rate, and is on par with the NO 3 - and NH 4 + wet fluxes. A second component of this study examined spatial differences in NO 3 - and NH 4

Watershed analysis

Science.gov (United States)

Alan Gallegos

2002-01-01

Watershed analyses and assessments for the Kings River Sustainable Forest Ecosystems Project were done on about 33,000 acres of the 45,500-acre Big Creek watershed and 32,000 acres of the 85,100-acre Dinkey Creek watershed. Following procedures developed for analysis of cumulative watershed effects (CWE) in the Pacific Northwest Region of the USDA Forest Service, the...

Assessing water quality of the Chesapeake Bay by the impact of sea level rise and warming

Science.gov (United States)

Wang, P.; Linker, L.; Wang, H.; Bhatt, G.; Yactayo, G.; Hinson, K.; Tian, R.

2017-08-01

The influence of sea level rise and warming on circulation and water quality of the Chesapeake Bay under projected climate conditions in 2050 were estimated by computer simulation. Four estuarine circulation scenarios in the estuary were run using the same watershed load in 1991-2000 period. They are, 1) the Base Scenario, which represents the current climate condition, 2) a Sea Level Rise Scenario, 3) a Warming Scenario, and 4) a combined Sea Level Rise and Warming Scenario. With a 1.6-1.9°C increase in monthly air temperatures in the Warming Scenario, water temperature in the Bay is estimated to increase by 0.8-1°C. Summer average anoxic volume is estimated to increase 1.4 percent compared to the Base Scenario, because of an increase in algal blooms in the spring and summer, promotion of oxygen consumptive processes, and an increase of stratification. However, a 0.5-meter Sea Level Rise Scenario results in a 12 percent reduction of anoxic volume. This is mainly due to increased estuarine circulation that promotes oxygen-rich sea water intrusion in lower layers. The combined Sea Level Rise and Warming Scenario results in a 10.8 percent reduction of anoxic volume. Global warming increases precipitation and consequently increases nutrient loads from the watershed by approximately 5-7 percent. A scenario that used a 10 percent increase in watershed loads and current estuarine circulation patterns yielded a 19 percent increase in summer anoxic volume, while a scenario that used a 10 percent increase in watershed loads and modified estuarine circulation patterns by the aforementioned sea level rise and warming yielded a 6 percent increase in summer anoxic volume. Impacts on phytoplankton, sediments, and water clarity were also analysed.

A conceptual hydrologic model for a forested Carolina bay depressional wetland on the Coastal Plain of South Carolina, USA

Science.gov (United States)

Jennifer E. Pyzoha; Timothy J. Callahan; Ge Sun; Carl C. Trettin; Masato Miwa

2008-01-01

This paper describes how climate influences the hydrology of an ephemeral depressional wetland. Surface water and groundwater elevation data were collected for 7 years in a Coastal Plain watershed in South Carolina USA containing depressional wetlands, known as Carolina bays. Rainfall and temperature data were compared with water-table well and piezometer data in and...

Reproductive health of yellow perch Perca flavescens in selected tributaries of the Chesapeake Bay

Energy Technology Data Exchange (ETDEWEB)

Blazer, Vicki S., E-mail: Vblazer@usgs.gov [U.S. Geological Survey, National Fish Health Research Laboratory, Leetown Science Center, 11649 Leetown Road, Kearneysville, WV 25430 (United States); Pinkney, Alfred E., E-mail: Fred_Pinkeny@fws.gov [U.S. Fish and Wildlife Service, Chesapeake Bay Field Office, 177 Admiral Cochrane Drive, Annapolis, MD 21401 (United States); Jenkins, Jill A., E-mail: jenkinsj@usgs.gov [U.S. Geological Survey, National Wetlands Research Center, 700 Cajundome Blvd., Lafayette, LA 70506 (United States); Iwanowicz, Luke R., E-mail: Liwanowicz@usgs.gov [U.S. Geological Survey, National Fish Health Research Laboratory, Leetown Science Center, 11649 Leetown Road, Kearneysville, WV 25430 (United States); Minkkinen, Steven, E-mail: steve_minkkinen@fws.gov [U.S. Fish and Wildlife Service, Chesapeake Bay Field Office, 177 Admiral Cochrane Drive, Annapolis, MD 21401 (United States); Draugelis-Dale, Rassa O., E-mail: daler@usgs.gov [U.S. Geological Survey, National Wetlands Research Center, 700 Cajundome Blvd., Lafayette, LA 70506 (United States); Uphoff, James H., E-mail: juphoff@dnr.state.md.us [Maryland Department of Natural Resources, Fisheries Service, Cooperative Oxford Laboratory, 904 South Morris Street, Oxford, MD 21654 (United States)

2013-03-01

Reduced recruitment of yellow perch has been noted for a number of years in certain urbanized watersheds (South and Severn Rivers) of the Chesapeake Bay. Other rapidly developing watersheds such as Mattawoman Creek are more recently showing evidence of reduced recruitment of anadromous fishes. In this study, we used a battery of biomarkers to better document the reproductive health of adult yellow perch collected during spring spawning in 2007–2009. Perch were collected in the South and Severn Rivers, Mattawoman Creek and the less developed Choptank and Allen's Fresh watersheds for comparison. Gonadosomatic indices, plasma reproductive hormone concentrations, plasma vitellogenin concentrations and gonad histology were evaluated in mature perch of both sexes. In addition, sperm quantity (cell counts) and quality (total and progressive motility, spermatogenic stage and DNA integrity), were measured in male perch. Many of these biomarkers varied annually and spatially, with some interesting statistical results and trends. Male perch from the Choptank and Allen's Fresh had generally higher sperm counts. In 2008 counts were significantly lower in the perch from the Severn when compared to other sites. The major microscopic gonadal abnormality in males was the proliferation of putative Leydig cells, observed in testes from Severn and less commonly, Mattawoman Creek perch. Observations that could significantly impact egg viability were an apparent lack of final maturation, abnormal yolk and thin, irregular zona pellucida. These were observed primarily in ovaries from Severn, South and less commonly Mattawoman Creek perch. The potential association of these observations with urbanization, impervious surface and chemical contaminants is discussed. - Highlights: ► Reduced recruitment of yellow perch has occurred in urban tributaries of Chesapeake Bay. ► We compared reproductive health biomarkers in perch from two urban, one developing, two less developed

Reproductive health of yellow perch Perca flavescens in selected tributaries of the Chesapeake Bay

International Nuclear Information System (INIS)

Blazer, Vicki S.; Pinkney, Alfred E.; Jenkins, Jill A.; Iwanowicz, Luke R.; Minkkinen, Steven; Draugelis-Dale, Rassa O.; Uphoff, James H.

2013-01-01

Reduced recruitment of yellow perch has been noted for a number of years in certain urbanized watersheds (South and Severn Rivers) of the Chesapeake Bay. Other rapidly developing watersheds such as Mattawoman Creek are more recently showing evidence of reduced recruitment of anadromous fishes. In this study, we used a battery of biomarkers to better document the reproductive health of adult yellow perch collected during spring spawning in 2007–2009. Perch were collected in the South and Severn Rivers, Mattawoman Creek and the less developed Choptank and Allen's Fresh watersheds for comparison. Gonadosomatic indices, plasma reproductive hormone concentrations, plasma vitellogenin concentrations and gonad histology were evaluated in mature perch of both sexes. In addition, sperm quantity (cell counts) and quality (total and progressive motility, spermatogenic stage and DNA integrity), were measured in male perch. Many of these biomarkers varied annually and spatially, with some interesting statistical results and trends. Male perch from the Choptank and Allen's Fresh had generally higher sperm counts. In 2008 counts were significantly lower in the perch from the Severn when compared to other sites. The major microscopic gonadal abnormality in males was the proliferation of putative Leydig cells, observed in testes from Severn and less commonly, Mattawoman Creek perch. Observations that could significantly impact egg viability were an apparent lack of final maturation, abnormal yolk and thin, irregular zona pellucida. These were observed primarily in ovaries from Severn, South and less commonly Mattawoman Creek perch. The potential association of these observations with urbanization, impervious surface and chemical contaminants is discussed. - Highlights: ► Reduced recruitment of yellow perch has occurred in urban tributaries of Chesapeake Bay. ► We compared reproductive health biomarkers in perch from two urban, one developing, two less developed watersheds. �

Determining Sediment Sources in the Anacostia River Watershed

Science.gov (United States)

Devereux, O. H.; Needelman, B. A.; Prestegaard, K. L.; Gellis, A. C.; Ritchie, J. C.

2005-12-01

Suspended sediment is a water-quality problem in the Chesapeake Bay. This project is designed to identify sediment sources in an urban watershed, the Northeast Branch of the Anacostia River (in Washington, D.C. and Maryland - drainage area = 188.5 km2), which delivers sediment directly to the Bay. This watershed spans two physiographic regions - the Piedmont and Coastal Plain. Bank sediment and suspended-sediment deposits were characterized using the following techniques: radionuclide (Cs-137) analysis by gamma ray spectrometry, trace-element analysis by ICP-MS, clay mineralogy by XRD, and particle-size analysis by use of a laser particle-size analyzer. Sampling of bank and suspended sediment was designed to: a) characterize tributary inputs from both Piedmont and Coastal Plain sources, and b) differentiate tributary inputs from bank erosion along the main stem of the Northeast Branch. Thirteen sample sites were chosen that represent tributary source areas of each physiographic region and the main stem where mixing occurs. Surface samples of the banks were compared to overbank deposits from a ten year storm (a proxy for the suspended sediments). Fingerprint components are selected from these data. Cesium-137 concentrations were analyzed for bank and overbank deposits for each physiographic region. No clear differences were seen between the two physiographic regions. Significant differences were observed between upland tributaries and the main stem of the Anacostia River. The average activity of Cs-137 for the tributaries was 5.4 bq/kg and the average for the main stem was 1.1 bq/kg. This suggests that there is significant erosion and storage of sediment in the tributaries. The low activity from Cs-137 in the main stem suggests a lack of storage of sediment along the main stem of the river. For the trace-element data, we focused on elements that showed significant variation among the sites. For the bank sediment, these elements include: Sr, V, Y, Ce, and Nd. For the

Characterizing submarine ground‐water discharge using fiber‐optic distributed temperature sensing and marine electrical resistivity

Science.gov (United States)

Henderson, Rory; Day-Lewis, Frederick D.; Lane, John W.; Harvey, Charles F.; Liu, Lanbo

2008-01-01

Submarine ground‐water discharge (SGD) contributes important solute fluxes to coastal waters. Pollutants are transported to coastal ecosystems by SGD at spatially and temporally variable rates. New approaches are needed to characterize the effects of storm‐event, tidal, and seasonal forcing on SGD. Here, we evaluate the utility of two geophysical methods‐fiber‐optic distributed temperature sensing (FO‐DTS) and marine electrical resistivity (MER)—for observing the spatial and temporal variations in SGD and the configuration of the freshwater/saltwater interface within submarine sediments. FO‐DTS and MER cables were permanently installed into the estuary floor on a transect extending 50 meters offshore under Waquoit Bay, Massachusetts, at the Waquoit Bay National Estuarine Research Reserve, and nearly continuous data were collected for 4 weeks in summer 2007. Initial results indicate that the methods are extremely useful for monitoring changes in the complex estuarine environment. The FO‐DTS produced time‐series data at approximately 1‐meter increments along the length of the fiber at approximately 29‐second intervals. The temperature time‐series data show that the temperature at near‐shore locations appears to be dominated by a semi‐diurnal (tidal) signal, whereas the temperature at off‐shore locations is dominated by a diurnal signal (day/night heating and cooling). Dipole‐dipole MER surveys were completed about every 50 minutes, allowing for production of high‐resolution time‐lapse tomograms, which provide insight into the variations of the subsurface freshwater/saltwater interface. Preliminary results from the MER data show a high‐resistivity zone near the shore at low tide, indicative of SGD, and consistent with the FO‐DTS results.

Watershed management in Myanmar

International Nuclear Information System (INIS)

Choi, K.S.

1993-01-01

Watershed degradation, watershed management, background of watershed management in Myanmar (condition of watershed, manpower), discussion and recommendation (proposed administrative structure, the need for watershed survey and planning, bottom-up approach) are emphasized. Watershed management, after all can be seen that it is the interphase between the forest, agriculture, soil, wildlife and the local communities

Watershed management in Myanmar

Energy Technology Data Exchange (ETDEWEB)

Choi, K S

1993-10-01

Watershed degradation, watershed management, background of watershed management in Myanmar (condition of watershed, manpower), discussion and recommendation (proposed administrative structure, the need for watershed survey and planning, bottom-up approach) are emphasized. Watershed management, after all can be seen that it is the interphase between the forest, agriculture, soil, wildlife and the local communities

Trend analysis of stressors and ecological responses, particularly nutrients, in the Narragansett Bay Watershed.

Science.gov (United States)

Current and historic impacts of nitrogen on water quality were evaluated and relationships between nutrients and ecosystem structure and function were developed for Narragansett Bay, RI. Land use land cover change analysis from 1985 thru 2005 resulted in a 7% increase in urban la...

Identification of High Potential Bays for HABs Occurrence in Peninsular Malysia Using Palsar Remote Sensing Data

Science.gov (United States)

Pour, A. B.; Hashim, M.

2016-09-01

Increasing frequency, intensity, and geographic distribution of Harmful algal blooms (HABs) poses a serious threat to the coastal fish/shellfish aquaculture and fisheries in Malaysian bays. Rising in sea level, shoreline erosion, stresses on fisheries, population pressure, interference of land-use and lack of institutional capabilities for integrated management make major challenges. Recent investigations and satellite observations indicate HABs originated from specific coast that have favourable geographic, geomorphic and coastal geology conditions to bring the green macro algae from the coast offshore. Therefore, the identification of high HABs frequented bays using remote sensing and geology investigations in Malaysian waters is required to reduce future challenges in this unique case. This research implemented comprehensive geomorphic and coastal geology investigations combined with remote sensing digital image processing approach to identify Malaysian bays frequented with HABs occurrence in Malaysian waters territory. The landscape and geomorphological features of the Malaysian bays were constructed from the Phased Array type L-band Synthetic Aperture Radar (PALSAR) remote sensing satellite data combined with field observations and surveying. The samples for laboratory analysis were collected from the sediment stations with different distance across shorelines features and watersheds of the Johor Bahru estuary. This research identified that semi-enclosed bays such as Kuala Lumpur and Johor Bahru bays with connection to estuaries have high potential to be frequented with HABs occurrence.

IDENTIFICATION OF HIGH POTENTIAL BAYS FOR HABs OCCURRENCE IN PENINSULAR MALYSIA USING PALSAR REMOTE SENSING DATA

Directory of Open Access Journals (Sweden)

A. B. Pour

2016-09-01

Full Text Available Increasing frequency, intensity, and geographic distribution of Harmful algal blooms (HABs poses a serious threat to the coastal fish/shellfish aquaculture and fisheries in Malaysian bays. Rising in sea level, shoreline erosion, stresses on fisheries, population pressure, interference of land-use and lack of institutional capabilities for integrated management make major challenges. Recent investigations and satellite observations indicate HABs originated from specific coast that have favourable geographic, geomorphic and coastal geology conditions to bring the green macro algae from the coast offshore. Therefore, the identification of high HABs frequented bays using remote sensing and geology investigations in Malaysian waters is required to reduce future challenges in this unique case. This research implemented comprehensive geomorphic and coastal geology investigations combined with remote sensing digital image processing approach to identify Malaysian bays frequented with HABs occurrence in Malaysian waters territory. The landscape and geomorphological features of the Malaysian bays were constructed from the Phased Array type L-band Synthetic Aperture Radar (PALSAR remote sensing satellite data combined with field observations and surveying. The samples for laboratory analysis were collected from the sediment stations with different distance across shorelines features and watersheds of the Johor Bahru estuary. This research identified that semi-enclosed bays such as Kuala Lumpur and Johor Bahru bays with connection to estuaries have high potential to be frequented with HABs occurrence.

Spatial patterning of water quality in Biscayne Bay, Florida as a function of land use and water management.

Science.gov (United States)

Caccia, Valentina G; Boyer, Joseph N

2005-11-01

An objective classification analysis was performed on a water quality data set from 25 sites collected monthly during 1994-2003. The water quality parameters measured included: TN, TON, DIN, NH4+, NO3-, NO2-, TP, SRP, TN:TP ratio, TOC, DO, CHL A, turbidity, salinity and temperature. Based on this spatial analysis, Biscayne Bay was divided into five zones having similar water quality characteristics. A robust nutrient gradient, driven mostly by dissolved inorganic nitrogen, from alongshore to offshore in the main Bay, was a large determinant in the spatial clustering. Two of these zones (Alongshore and Inshore) were heavily influenced by freshwater input from four canals which drain the South Dade agricultural area, Black Point Landfill, and sewage treatment plant. The North Bay zone, with high turbidity, phytoplankton biomass, total phosphorus, and low DO, was affected by runoff from five canals, the Munisport Landfill, and the urban landscape. The South Bay zone, an embayment surrounded by mangrove wetlands with little urban development, was high in dissolved organic constituents but low in inorganic nutrients. The Main Bay was the area most influenced by water exchange with the Atlantic Ocean and showed the lowest nutrient concentrations. The water quality in Biscayne Bay is therefore highly dependent of the land use and influence from the watershed.

Geology, Hydrology, and Water Quality of the Little Blackwater River Watershed, Dorchester County, Maryland, 2006-09

Science.gov (United States)

Fleming, Brandon J.; DeJong, Benjamin D.; Phelan, Daniel J.

2011-01-01

The Little Blackwater River watershed is a low-lying tidal watershed in Dorchester County, Maryland. The potential exists for increased residential development in a mostly agricultural watershed that drains into the Blackwater National Wildlife Refuge. Groundwater and surface-water levels were collected along with water-quality samples to document hydrologic and geochemical conditions within the watershed prior to potential land-use changes. Lithologic logs were collected in the Little Blackwater River watershed and interpreted with existing geophysical logs to conceptualize the shallow groundwater-flow system. A shallow water table exists in much of the watershed as shown by sediment cores and surface geophysical surveys. Water-table wells have seasonal variations of 6 feet, with the lowest water levels occurring in September and October. Seasonally low water-table levels are lower than the stage of the Little Blackwater River, creating the potential for surface-water infiltration into the water table. Two stream gages, each equipped with stage, velocity, specific conductance, and temperature sensors, were installed at the approximate mid-point of the watershed and near the mouth of the Little Blackwater River. The gages recorded data continuously and also were equipped with telemetry. Discharge calculated at the mouth of the Little Blackwater River showed a seasonal pattern, with net positive discharge in the winter and spring months and net negative discharge (flow into the watershed from Blackwater National Wildlife Refuge and Fishing Bay) in the summer and fall months. Continuous water-quality records showed an increase in specific conductance during the summer and fall months. Discrete water-quality samples were collected during 2007--08 from 13 of 15 monitoring wells and during 2006--09 from 9 surface-water sites to characterize pre-development conditions and the seasonal variability of inorganic constituents and nutrients. The highest mean values of

Factors affecting spatial and temporal variability in material exchange between the Southern Everglades wetlands and Florida Bay (USA)

Science.gov (United States)

Sutula, Martha A.; Perez, Brian C.; Reyes, Enrique; Childers, Daniel L.; Davis, Steve; Day, John W.; Rudnick, David; Sklar, Fred

2003-08-01

Physical and biological processes controlling spatial and temporal variations in material concentration and exchange between the Southern Everglades wetlands and Florida Bay were studied for 2.5 years in three of the five major creek systems draining the watershed. Daily total nitrogen (TN), and total phosphorus (TP) fluxes were measured for 2 years in Taylor River, and ten 10-day intensive studies were conducted in this creek to estimate the seasonal flux of dissolved inorganic nitrogen (N), phosphorus (P), total organic carbon (TOC), and suspended matter. Four 10-day studies were conducted simultaneously in Taylor, McCormick, and Trout Creeks to study the spatial variation in concentration and flux. The annual fluxes of TOC, TN, and TP from the Southern Everglades were estimated from regression equations. The Southern Everglades watershed, a 460-km 2 area that includes Taylor Slough and the area south of the C-111 canal, exported 7.1 g C m -2, 0.46 g N m -2, and 0.007 g P m -2, annually. Everglades P flux is three to four orders of magnitude lower than published flux estimates from wetlands influenced by terrigenous sedimentary inputs. These low P flux values reflect both the inherently low P content of Everglades surface water and the efficiency of Everglades carbonate sediments and biota in conserving and recycling this limiting nutrient. The seasonal variation of freshwater input to the watershed was responsible for major temporal variations in N, P, and C export to Florida Bay; approximately 99% of the export occurred during the rainy season. Wind-driven forcing was most important during the later stages of the dry season when low freshwater head coincided with southerly winds, resulting in a net import of water and materials into the wetlands. We also observed an east to west decrease in TN:TP ratio from 212:1 to 127:1. Major spatial gradients in N:P ratios and nutrient concentration and flux among the creek were consistent with the westward decrease in

Assessment of watershed scale nitrogen cycling and dynamics by hydrochemical modeling

Science.gov (United States)

Onishi, T.; Hiramatsu, K.; Somura, H.

2017-12-01

Nitrogen cycling in terrestrial areas is affecting water quality and ecosystem of aquatic area such as lakes and oceans through rivers. Owing to the intensive researches on nitrogen cycling in each different type of ecosystem, we acquired rich knowledge on nitrogen cycling of each ecosystem. On the other hand, since watershed are composed of many different kinds of ecosystems, nitrogen cycling in a watershed as a complex of these ecosystems is not well quantified. Thus, comprehensive understanding of nitrogen cycling of watersheds by modelling efforts are required. In this study, we attempted to construct hydrochemical model of the Ise Bay watershed to reproduce discharge, TN, and NO3 concentration. The model is based on SWAT (Soil and Water Assessment Tools) model. As anthropogenic impacts related to both hydrological cycling and nitrogen cycling, agricultural water intake/drainage, and domestic water intake/drainage were considered. In addition, fertilizer input to agricultural lands were also considered. Calibration period and validation period are 2004-2006, and 2007-2009, respectively. As a result of calibration using 2000 times LCS (Latin Cubic Sampling) method, discharge of rivers were reproduced fairly well with NS of 0.6-0.8. In contrast, the calibration result of TN and NO3 concentration tended to show overestimate values in spite of considering parameter uncertainties. This implies that unimplemented denitrification processes in the model. Through exploring the results, it is indicated that riparian areas, and agricultural drainages might be important spots for denitrification. Based on the result, we also attempted to evaluate the impact of climate change on nitrogen cycling. Though it is fully explored, this result will also be reported.

Lawrence Livermore National Laboratory Surface Water Protection: A Watershed Approach

Energy Technology Data Exchange (ETDEWEB)

Coty, J

2009-03-16

is largely developed yet its surface water system encompasses two arroyos, an engineered detention basin (Lake Haussmann), storm channels, and wetlands. Conversely, the more rural Site 300 includes approximately 7,000 acres of largely undeveloped land with many natural tributaries, riparian habitats, and wetland areas. These wetlands include vernal pools, perennial seeps, and emergent wetlands. The watersheds within which the Laboratory's sites lie provide local and community ecological functions and services which require protection. These functions and services include water supply, flood attenuation, groundwater recharge, water quality improvement, wildlife and aquatic habitats, erosion control, and (downstream) recreational opportunities. The Laboratory employs a watershed approach to protect these surface water systems. The intent of this approach, presented in this document, is to provide an integrated effort to eliminate or minimize any adverse environmental impacts of the Laboratory's operations and enhance the attributes of these surface water systems, as possible and when reasonable, to protect their value to the community and watershed. The Laboratory's watershed approach to surface water protection will use the U.S. Environmental Protection Agency's Watershed Framework and guiding principles of geographic focus, scientifically based management and partnerships1 as a foundation. While the Laboratory's unique site characteristics result in objectives and priorities that may differ from other industrial sites, these underlying guiding principles provide a structure for surface water protection to ensure the Laboratory's role in environmental stewardship and as a community partner in watershed protection. The approach includes pollution prevention, continual environmental improvement, and supporting, as possible, community objectives (e.g., protection of the San Francisco Bay watershed).

Locating Groundwater Pathways of Anthropogenic Contaminants Using a Novel Approach in Kānéohe Watershed, Óahu, Hawaíi

Science.gov (United States)

McKenzie, T.; Dulai, H.; Popp, B. N.; Whittier, R. B.

2017-12-01

We have applied a novel approach using radon, δ15N and δ18O values of nitrate, and contaminants of emerging concern (CECs) to identify groundwater pathways of anthropogenic contaminants. This approach was applied in Kānéohe watershed, located on the windward side of Óahu, which has been subject to persistent near shore water pollution. Previous research has indicated that there are strong seasonal differences between surface runoff and groundwater discharge into Kānéohe Bay. Three sub-watersheds of varying land-use (e.g. cesspool density, agriculture, urbanization) bordering Kānéohe Bay were studied. Seasonality, as well as spatial and temporal variations of groundwater discharge into streams and the bay were captured by a series of snapshot studies using a natural isotope of radon as a tracer for groundwater inflow. δ15N and δ18O values of nitrate were used as source tracking tools to determine the potential origin (e.g. wastewater, agriculture) of nitrate. These results were paired with spatial analysis of land-use and further coupled with CEC concentrations in order to evaluate how land-use relates to stream and groundwater contaminant distribution. Previously unrecognized groundwater pathways for contaminant transport were identified using radon in conjunction with CEC and stable isotopic techniques. We present results for stream and coastal water quality, focusing on nutrient and CEC fluxes across the land-ocean interface, as well as discuss the application of CECs as novel wastewater tracers.

EPA H2O Software Tool

Science.gov (United States)

EPA H2O allows user to: Understand the significance of EGS in Tampa Bay watershed; visually analyze spatial distribution of the EGS in Tampa Bay watershed; obtain map and summary statistics of EGS values in Tampa Bay watershed; analyze and compare potential impacts of development...

Suspended sediment and sediment-associated contaminants in San Francisco Bay

Science.gov (United States)

Schoellhamer, D.H.; Mumley, T.E.; Leatherbarrow, J.E.

2007-01-01

Water-quality managers desire information on the temporal and spatial variability of contaminant concentrations and the magnitudes of watershed and bed-sediment loads in San Francisco Bay. To help provide this information, the Regional Monitoring Program for Trace Substances in the San Francisco Estuary (RMP) takes advantage of the association of many contaminants with sediment particles by continuously measuring suspended-sediment concentration (SSC), which is an accurate, less costly, and more easily measured surrogate for several trace metals and organic contaminants. Continuous time series of SSC are collected at several sites in the Bay. Although semidiurnal and diurnal tidal fluctuations are present, most of the variability of SSC occurs at fortnightly, monthly, and semiannual tidal time scales. A seasonal cycle of sediment inflow, wind-wave resuspension, and winnowing of fine sediment also is observed. SSC and, thus, sediment-associated contaminants tend to be greater in shallower water, at the landward ends of the Bay, and in several localized estuarine turbidity maxima. Although understanding of sediment transport has improved in the first 10 years of the RMP, determining a simple mass budget of sediment or associated contaminants is confounded by uncertainties regarding sediment flux at boundaries, change in bed-sediment storage, and appropriate modeling techniques. Nevertheless, management of sediment-associated contaminants has improved greatly. Better understanding of sediment and sediment-associated contaminants in the Bay is of great interest to evaluate the value of control actions taken and the need for additional controls. ?? 2007 Elsevier Inc. All rights reserved.

Management case study: Tampa Bay, Florida

Science.gov (United States)

Morrison, Gerold; Greening, Holly; Yates, Kimberly K.; Wolanski, Eric; McLusky, Donald S.

2011-01-01

Tampa Bay, Florida, USA, is a shallow, subtropical estuary that experienced severe cultural eutrophication between the 1940s and 1980s, a period when the human population of its watershed quadrupled. In response, citizen action led to the formation of a public- and private-sector partnership (the Tampa Bay Estuary Program), which adopted a number of management objectives to support the restoration and protection of the bay’s living resources. These included numeric chlorophyll a and water-clarity targets, as well as long-term goals addressing the spatial extent of seagrasses and other selected habitat types, to support estuarine-dependent faunal guilds. Over the past three decades, nitrogen controls involving sources such as wastewater treatment plants, stormwater conveyance systems, fertilizer manufacturing and shipping operations, and power plants have been undertaken to meet these and other management objectives. Cumulatively, these controls have resulted in a 60% reduction in annual total nitrogen (TN) loads relative to earlier worse-case (latter 1970s) conditions. As a result, annual water-clarity and chlorophyll a targets are currently met in most years, and seagrass cover measured in 2008 was the highest recorded since 1950. Factors that have contributed to the observed improvements in Tampa Bay over the past several decades include the following: (1) Development of numeric, science-based water-quality targets to meet a long-term goal of restoring seagrass acreage to 1950s levels. Empirical and mechanistic models found that annual average chlorophyll a concentrations were a primary manageable factor affecting light attenuation. The models also quantified relationships between TN loads, chlorophyll a concentrations, light attenuation, and fluctuations in seagrass cover. The availability of long-term monitoring data, and a systematic process for using the data to evaluate the effectiveness of management actions, has allowed managers to track progress and

Does centennial morphodynamic evolution lead to higher channel efficiency in San Pablo Bay, California?

Science.gov (United States)

van der Wegen, M.; Jaffe, B.E.; Barnard, P.L.; Jaffee, B.E.; Schoellhamer, D.H.

2013-01-01

Measured bathymetries on 30 year interval over the past 150 years show that San Pablo Bay experienced periods of considerable deposition followed by periods of net erosion. However, the main channel in San Pablo Bay has continuously narrowed. The underlying mechanisms and consequences of this tidal channel evolution are not well understood. The central question of this study is whether tidal channels evolve towards a geometry that leads to more efficient hydraulic conveyance and sediment throughput. We applied a hydrodynamic process-based, numerical model (Delft3D), which was run on 5 San Pablo Bay bathymetries measured between 1856 and 1983. Model results shows increasing energy dissipation levels for lower water flows leading to an approximately 15% lower efficiency in 1983 compared to 1856. During the same period the relative seaward sediment throughput through the San Pablo Bay main channel increased by 10%. A probable explanation is that San Pablo Bay is still affected by the excessive historic sediment supply. Sea level rise and Delta surface water area variations over 150 years have limited effect on the model results. With expected lower sediment concentrations in the watershed and less impact of wind waves due to erosion of the shallow flats, it is possible that energy dissipations levels will decrease again in future decades. Our study suggests that the morphodynamic adaptation time scale to excessive variations in sediment supply to estuaries may be on the order of centuries.

Evaluating Hydrologic Response of an Agricultural Watershed for Watershed Analysis

Directory of Open Access Journals (Sweden)

Manoj Kumar Jha

2011-06-01

Full Text Available This paper describes the hydrological assessment of an agricultural watershed in the Midwestern United States through the use of a watershed scale hydrologic model. The Soil and Water Assessment Tool (SWAT model was applied to the Maquoketa River watershed, located in northeast Iowa, draining an agriculture intensive area of about 5,000 km2. The inputs to the model were obtained from the Environmental Protection Agency’s geographic information/database system called Better Assessment Science Integrating Point and Nonpoint Sources (BASINS. Meteorological input, including precipitation and temperature from six weather stations located in and around the watershed, and measured streamflow data at the watershed outlet, were used in the simulation. A sensitivity analysis was performed using an influence coefficient method to evaluate surface runoff and baseflow variations in response to changes in model input hydrologic parameters. The curve number, evaporation compensation factor, and soil available water capacity were found to be the most sensitive parameters among eight selected parameters. Model calibration, facilitated by the sensitivity analysis, was performed for the period 1988 through 1993, and validation was performed for 1982 through 1987. The model was found to explain at least 86% and 69% of the variability in the measured streamflow data for calibration and validation periods, respectively. This initial hydrologic assessment will facilitate future modeling applications using SWAT to the Maquoketa River watershed for various watershed analyses, including watershed assessment for water quality management, such as total maximum daily loads, impacts of land use and climate change, and impacts of alternate management practices.

Dissolved Organic Matter (DOM) Export from Watersheds to Coastal Oceans

Science.gov (United States)

Chen, R. F.; Gardner, G. B.; Peri, F.

2016-02-01

Dissolved organic matter (DOM) from terrestrial plants and soils is transported by surface waters and groundwaters to coastal ocean waters. Along the way, photochemical and biological degradation can remove DOM, and in situ processes such as phytoplankton leaching and sediment sources can add to the DOM in the river water. Wetlands, especially coastal wetlands can add significant amounts of DOM that is carried by rivers and is exported through estuaries to coastal systems. We will present observational data from a variety of coastal systems (San Francisco Bay, Boston Harbor, Chesapeake Bay, Hudson River, the Mississippi River, and a small salt marsh in the Gulf of Mexico). High resolution measurements of chromophoric dissolved organic matter (CDOM) can be correlated with dissolved organic carbon (DOC) so can be used to estimate DOC in specific systems and seasons. Gradients in CDOM/DOC combined with water fluxes can be used to estimate DOC fluxes from a variety of coastal watersheds to coastal systems. Influences of land use, system size, residence time, DOM quality, and photochemical and biological degradation will be discussed. The significance of coastal wetlands in the land-to-ocean export of DOC will be emphasized.

The role of power plant atmospheric emissions in the deposition of nitrogen to the Chesapeake Bay

International Nuclear Information System (INIS)

Miller, P.E.

1994-01-01

The Maryland Power Plant Research Program (PPRP) has sponsored research on several aspects of atmospheric nitrogen emissions, source attribution, deposition estimation and impact assessment since the mid-eighties. The results of these studies will be presented and discussed in the context of power plant emissions control impact on nitrogen loadings to the Chesapeake Bay and watershed. Information needs with respect to power plant contribution and emission control policy will be identified and discussed from the perspective of PPRP

Enhanced land subsidence in Galveston Bay, Texas: Interaction between sediment accumulation rates and relative sea level rise

Science.gov (United States)

Al Mukaimi, Mohammad E.; Dellapenna, Timothy M.; Williams, Joshua R.

2018-07-01

Galveston Bay is the second largest estuary along the northern Gulf of Mexico coast, with a watershed containing one of largest concentrations of petroleum and chemical industries globally, as well as Houston, the fifth largest metropolitan area in the USA. Throughout the last century, extensive groundwater extraction to support these industries and an expanding population has resulted in significantly enhanced land subsidence (0.6-3.0 cm yr-1). The highest subsidence rates observed in the bay are within the lower 15 km of the San Jacinto River/Houston Ship Channel region (SJR/HSC), with distal areas in East and West Galveston Bays having subsidence rates on the order of 0.2 cm yr-1. In order to investigate the impacts of subsidence on sedimentation, a series of 22 vibracores were collected throughout the bay, and 210Pb and 137Cs radioisotope geochronologies and grain size distributions were determined. Sediment accumulation rates are highest (1.9 ± 0.5 cm yr-1) in the SJR/HSC, and decrease (sedimentation rates are significantly (p sedimentation rates are lower (as much as 50%) than estimated RSLR, indicating a sediment accretionary deficit. In areas (e.g., Scott Bay) within the SJR/HSC, the bay has deepened by more than 1.5 m, suggesting that sediment accumulation cannot keep pace with RSLR. Ultimately, this has resulted in a loss of coastal wetlands and a conversion of marine habitats from relatively shallow to deeper water settings.

Weighted Regressions on Time, Discharge, and Season (WRTDS), with an application to Chesapeake Bay River inputs

Science.gov (United States)

Hirsch, Robert M.; Moyer, Douglas; Archfield, Stacey A.

2010-01-01

A new approach to the analysis of long-term surface water-quality data is proposed and implemented. The goal of this approach is to increase the amount of information that is extracted from the types of rich water-quality datasets that now exist. The method is formulated to allow for maximum flexibility in representations of the long-term trend, seasonal components, and discharge-related components of the behavior of the water-quality variable of interest. It is designed to provide internally consistent estimates of the actual history of concentrations and fluxes as well as histories that eliminate the influence of year-to-year variations in streamflow. The method employs the use of weighted regressions of concentrations on time, discharge, and season. Finally, the method is designed to be useful as a diagnostic tool regarding the kinds of changes that are taking place in the watershed related to point sources, groundwater sources, and surface-water nonpoint sources. The method is applied to datasets for the nine large tributaries of Chesapeake Bay from 1978 to 2008. The results show a wide range of patterns of change in total phosphorus and in dissolved nitrate plus nitrite. These results should prove useful in further examination of the causes of changes, or lack of changes, and may help inform decisions about future actions to reduce nutrient enrichment in the Chesapeake Bay and its watershed.

Lignin phenols used to infer organic matter sources to Sepetiba Bay - RJ, Brasil

Science.gov (United States)

Rezende, C. E.; Pfeiffer, W. C.; Martinelli, L. A.; Tsamakis, E.; Hedges, J. I.; Keil, R. G.

2010-04-01

Lignin phenols were measured in the sediments of Sepitiba Bay, Rio de Janeiro, Brazil and in bedload sediments and suspended sediments of the four major fluvial inputs to the bay; São Francisco and Guandu Channels and the Guarda and Cação Rivers. Fluvial suspended lignin yields (Σ8 3.5-14.6 mgC 10 g dw -1) vary little between the wet and dry seasons and are poorly correlated with fluvial chlorophyll concentrations (0.8-50.2 μgC L -1). Despite current land use practices that favor grassland agriculture or industrial uses, fluvial lignin compositions are dominated by a degraded leaf-sourced material. The exception is the Guarda River, which has a slight influence from grasses. The Lignin Phenol Vegetation Index, coupled with acid/aldehyde and 3.5 Db/V ratios, indicate that degraded leaf-derived phenols are also the primary preserved lignin component in the bay. The presence of fringe Typha sp. and Spartina sp. grass beds surrounding portions of the Bay are not reflected in the lignin signature. Instead, lignin entering the bay appears to reflect the erosion of soils containing a degraded signature from the former Atlantic rain forest that once dominated the watershed, instead of containing a significant signature derived from current agricultural uses. A three-component mixing model using the LPVI, atomic N:C ratios, and stable carbon isotopes (which range between -26.8 and -21.8‰) supports the hypothesis that fluvial inputs to the bay are dominated by planktonic matter (78% of the input), with lignin dominated by leaf (14% of the input) over grass (6%). Sediments are composed of a roughly 50-50 mixture of autochthonous material and terrigenous material, with lignin being primarily sourced from leaf.

Watershed assessment-watershed analysis: What are the limits and what must be considered

Science.gov (United States)

Robert R. Ziemer

2000-01-01

Watershed assessment or watershed analysis describes processes and interactions that influence ecosystems and resources in a watershed. Objectives and methods differ because issues and opportunities differ.

Application of Watershed Scale Models to Predict Nitrogen Loading From Coastal Plain Watersheds

Science.gov (United States)

George M. Chescheir; Glenn P Fernandez; R. Wayne Skaggs; Devendra M. Amatya

2004-01-01

DRAINMOD-based watershed models have been developed and tested using data collected from an intensively instrumented research site on Kendricks Creek watershed near Plymouth. NC. These models were applied to simulate the hydrology and nitrate nitrogen (NO3-N) loading from two other watersheds in the Coastal Plain of North Carolina, the 11600 ha Chicod Creek watershed...

Acquisition Of Rainfall Dataset And The Application For The Automatic Harvester In The Chesapeake Bay Region

Science.gov (United States)

Choi, Y.; Piasecki, M.

2008-12-01

The objective of this study is the preparation and indexing of rainfall data products for ingestion into the Chesapeake Bay Environmental Observatory (CBEO) node of the CUAHSI/WATERs network. Rainfall products (which are obtained and then processed based on the WSR-88D NEXRAD network) are obtained from the NOAA/NWS Advanced Hydrologic Prediction Service that combines the Multi-sensor Precipitation Estimate (MPE) data generated by the Regional River Forecast Centers and Hydro-NEXRAD rainfall data generated as a service by the University of Iowa. The former is collected on 4*4 km grid (HRAP) with a daily average temporal resolution and the latter on a 1minute*1minute degree grid with hourly values. We have generated a cut-out for the Chesapeake Bay Basin that contains about 9,300 nodes (sites) for the MPE data and about 300,000 nodes (sites) for the Hydro-NEXRAD product. Automated harvesting services have been implemented for both data products. The MPE data is harvested from its download site using ArcGIS which in turn is used to extract the data for the Chesapeake Bay watershed before a scripting program is used to scatter the data into the ODM. The Hydro-NEXRAD is downloaded from a web-based system at the University of Iowa which permits downloads for large scale watersheds organized by Hydraulic Unit Codes (HUC). The resulting ASCII is then automatically parsed and the information stored alongside the MPE data. The two data products stored side-by-side then allows a comparison between them addressing the accuracy and agreement between the methods used to arrive at rainfall data as both use the raw reflectivity data from the WSD-88D system.

Evaluation of wetland implementation strategies on phosphorus reduction at a watershed scale

Science.gov (United States)

Abouali, Mohammad; Nejadhashemi, A. Pouyan; Daneshvar, Fariborz; Adhikari, Umesh; Herman, Matthew R.; Calappi, Timothy J.; Rohn, Bridget G.

2017-09-01

Excessive nutrient use in agricultural practices is a major cause of water quality degradation around the world, which results in eutrophication of the freshwater systems. Among the nutrients, phosphorus enrichment has recently drawn considerable attention due to major environmental issues such as Lake Erie and Chesapeake Bay eutrophication. One approach for mitigating the impacts of excessive nutrients on water resources is the implementation of wetlands. However, proper site selection for wetland implementation is the key for effective water quality management at the watershed scale, which is the goal of this study. In this regard, three conventional and two pseudo-random targeting methods were considered. A watershed model called the Soil and Water Assessment Tool (SWAT) was coupled with another model called System for Urban Stormwater Treatment and Analysis IntegratioN (SUSTAIN) to simulate the impacts of wetland implementation scenarios in the Saginaw River watershed, located in Michigan. The inter-group similarities of the targeting strategies were investigated and it was shown that the level of similarity increases as the target area increases (0.54-0.86). In general, the conventional targeting method based on phosphorus load generated per unit area at the subwatershed scale had the highest average reduction among all the scenarios (44.46 t/year). However, when considering the total area of implemented wetlands, the conventional method based on long-term impacts of wetland implementation showed the highest amount of phosphorus reduction (36.44 t/year).

Evaluating Hydrologic Response of an Agricultural Watershed for Watershed Analysis

OpenAIRE

Manoj Kumar Jha

2011-01-01

This paper describes the hydrological assessment of an agricultural watershed in the Midwestern United States through the use of a watershed scale hydrologic model. The Soil and Water Assessment Tool (SWAT) model was applied to the Maquoketa River watershed, located in northeast Iowa, draining an agriculture intensive area of about 5,000 km2. The inputs to the model were obtained from the Environmental Protection Agency’s geographic information/database system called Better Assessment Science...

Engaging Watershed Stakeholders for Cost-Effective Environmental Management Planning with "Watershed Manager"

Science.gov (United States)

Williams, Jeffery R.; Smith, Craig M.; Roe, Josh D.; Leatherman, John C.; Wilson, Robert M.

2012-01-01

"Watershed Manager" is a spreadsheet-based model that is used in extension education programs for learning about and selecting cost-effective watershed management practices to reduce soil, nitrogen, and phosphorus losses from cropland. It can facilitate Watershed Restoration and Protection Strategy (WRAPS) stakeholder groups' development…

Watershed-based survey designs

Science.gov (United States)

Detenbeck, N.E.; Cincotta, D.; Denver, J.M.; Greenlee, S.K.; Olsen, A.R.; Pitchford, A.M.

2005-01-01

Watershed-based sampling design and assessment tools help serve the multiple goals for water quality monitoring required under the Clean Water Act, including assessment of regional conditions to meet Section 305(b), identification of impaired water bodies or watersheds to meet Section 303(d), and development of empirical relationships between causes or sources of impairment and biological responses. Creation of GIS databases for hydrography, hydrologically corrected digital elevation models, and hydrologic derivatives such as watershed boundaries and upstream–downstream topology of subcatchments would provide a consistent seamless nationwide framework for these designs. The elements of a watershed-based sample framework can be represented either as a continuous infinite set defined by points along a linear stream network, or as a discrete set of watershed polygons. Watershed-based designs can be developed with existing probabilistic survey methods, including the use of unequal probability weighting, stratification, and two-stage frames for sampling. Case studies for monitoring of Atlantic Coastal Plain streams, West Virginia wadeable streams, and coastal Oregon streams illustrate three different approaches for selecting sites for watershed-based survey designs.

33 CFR 100.124 - Maggie Fischer Memorial Great South Bay Cross Bay Swim, Great South Bay, New York.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Maggie Fischer Memorial Great South Bay Cross Bay Swim, Great South Bay, New York. 100.124 Section 100.124 Navigation and Navigable... NAVIGABLE WATERS § 100.124 Maggie Fischer Memorial Great South Bay Cross Bay Swim, Great South Bay, New York...

Watershed Central: Harnessing a social media tool to organize local technical knowledge and find the right watershed resources for your watershed

Science.gov (United States)

Watershed Central was developed to be a bridge between sharing and searching for information relating to watershed issues. This is dependent upon active user support through additions and updates to the Watershed Central Wiki. Since the wiki is user driven, the content and applic...

Application of the Soil and Water Assessment Tool (SWAT Model on a small tropical island (Great River Watershed, Jamaica as a tool in Integrated Watershed and Coastal Zone Management

Directory of Open Access Journals (Sweden)

Orville P. Grey

2014-09-01

Full Text Available The Great River Watershed, located in north-west Jamaica, is critical for development, particularly for housing, tourism, agriculture, and mining. It is a source of sediment and nutrient loading to the coastal environment including the Montego Bay Marine Park. We produced a modeling framework using the Soil and Water Assessment Tool (SWAT and GIS. The calculated model performance statistics for high flow discharge yielded a Nash-Sutcliffe Efficiency (NSE value of 0.68 and a R² value of 0.70 suggesting good measured and simulated (calibrated discharge correlation. Calibration and validation results for streamflow were similar to the observed streamflows. For the dry season the simulated urban landuse scenario predicted an increase in surface runoff in excess of 150%. During the wet season it is predicted to range from 98 to 234% presenting a significant risk of flooding, erosion and other environmental issues. The model should be used for the remaining 25 watersheds in Jamaica and elsewhere in the Caribbean. The models suggests that projected landuse changes will have serious impacts on available water (streamflow, stream health, potable water treatment, flooding and sensitive coastal ecosystems.

Time series monitoring of water quality and microalgal diversity in a tropical bay under intense anthropogenic interference (SW coast of the Bay of Bengal, India)

Energy Technology Data Exchange (ETDEWEB)

Shaik, Aziz ur Rahman [CSIR — National Institute of Oceanography, Regional Centre, 176 Lawson' s Bay Colony, Visakhapatnam, AP 530017 (India); Biswas, Haimanti, E-mail: haimanti.biswas@nio.org [CSIR — National Institute of Oceanography, Regional Centre, 176 Lawson' s Bay Colony, Visakhapatnam, AP 530017 (India); Reddy, N.P.C.; Srinivasa Rao, V. [CSIR — National Institute of Oceanography, Regional Centre, 176 Lawson' s Bay Colony, Visakhapatnam, AP 530017 (India); Bharathi, M.D. [Present address: ICMAM Project Directorate, 2nd Floor, NIOT Campus, Velacherry-Tambaram Main Road, Pallikkaranai, Chennai 600100 (India); Subbaiah, Ch.V. [CSIR — National Institute of Oceanography, Regional Centre, 176 Lawson' s Bay Colony, Visakhapatnam, AP 530017 (India)

2015-11-15

In recent decades, material fluxes to coastal waters from various land based anthropogenic activities have significantly been enhanced around the globe which can considerably impact the coastal water quality and ecosystem health. Hence, there is a critical need to understand the links between anthropogenic activities in watersheds and its health. Kakinada Bay is situated at the SW part of the Bay of Bengal, near to the second largest mangrove cover in India with several fertilizer industries along its bank and could be highly vulnerable to different types of pollutants. However, virtually, no data is available so far reporting its physicochemical status and microalgal diversity at this bay. In order to fill this gap, we conducted three time series observations at a fixed station during January, December and June 2012, at this bay measuring more than 15 physical, chemical and biological parameters in every 3 h over a period of 36 h in both surface (0 m) and subsurface (4.5 m) waters. Our results clearly depict a strong seasonality between three sampling months; however, any abnormal values of nutrients, biological oxygen demand or dissolved oxygen level was not observed. A Skeletonema costatum bloom was observed in December which was probably influenced by low saline, high turbid and high Si input through the river discharge. Otherwise, smaller diatoms like Thalassiosira decipiens, Thalassiothrix frauenfeldii, and Thalassionema nitzschioides dominated the bay. It is likely that the material loading can be high at the point sources due to intense anthropogenic activities, however, gets diluted with biological, chemical and physical processes in the offshore waters. - Highlights: • No signature of enormous nutrient loading was observed over the diel cycle • Dissolved oxygen and BOD concentrations did not show any exceptional trend • Diatoms dominated more than 90% of the total phytoplankton communities • A Skeletonema Costatum (a centric diatom) bloom was

Time series monitoring of water quality and microalgal diversity in a tropical bay under intense anthropogenic interference (SW coast of the Bay of Bengal, India)

International Nuclear Information System (INIS)

Shaik, Aziz ur Rahman; Biswas, Haimanti; Reddy, N.P.C.; Srinivasa Rao, V.; Bharathi, M.D.; Subbaiah, Ch.V.

2015-01-01

In recent decades, material fluxes to coastal waters from various land based anthropogenic activities have significantly been enhanced around the globe which can considerably impact the coastal water quality and ecosystem health. Hence, there is a critical need to understand the links between anthropogenic activities in watersheds and its health. Kakinada Bay is situated at the SW part of the Bay of Bengal, near to the second largest mangrove cover in India with several fertilizer industries along its bank and could be highly vulnerable to different types of pollutants. However, virtually, no data is available so far reporting its physicochemical status and microalgal diversity at this bay. In order to fill this gap, we conducted three time series observations at a fixed station during January, December and June 2012, at this bay measuring more than 15 physical, chemical and biological parameters in every 3 h over a period of 36 h in both surface (0 m) and subsurface (4.5 m) waters. Our results clearly depict a strong seasonality between three sampling months; however, any abnormal values of nutrients, biological oxygen demand or dissolved oxygen level was not observed. A Skeletonema costatum bloom was observed in December which was probably influenced by low saline, high turbid and high Si input through the river discharge. Otherwise, smaller diatoms like Thalassiosira decipiens, Thalassiothrix frauenfeldii, and Thalassionema nitzschioides dominated the bay. It is likely that the material loading can be high at the point sources due to intense anthropogenic activities, however, gets diluted with biological, chemical and physical processes in the offshore waters. - Highlights: • No signature of enormous nutrient loading was observed over the diel cycle • Dissolved oxygen and BOD concentrations did not show any exceptional trend • Diatoms dominated more than 90% of the total phytoplankton communities • A Skeletonema Costatum (a centric diatom) bloom was

The experimental watersheds in Slovenia

International Nuclear Information System (INIS)

Sraj, M; Rusjan, S; Petan, S; Vidmar, A; Mikos, M; Globevnik, L; Brilly, M

2008-01-01

Experimental watersheds are critical to the advancement of hydrological science. By setting up three experimental watersheds, Slovenia also obtained its grounds for further development of the science and discipline. In the Dragonja experimental watershed the studies are focused on the afforestation of the watershed in a mediterranean climate, on the Reka river the water balance in a partly karstic area is examined, and on the case of the Glinscica stream the implications of the urban environment are studied. We have obtained valuable experience and tested new measuring equipment on all three experimental watersheds. Measurements and analysis on the experimental watersheds improved the current understanding of hydrological processes. They resulted in several PhD Theses, Master Theses and scientific articles. At the same time the experimental watersheds provide support to the teaching and studying process.

Lessons From Watershed-Based Climate Smart Agricultural Practices In Jogo-Gudedo Watershed Ethiopia

Directory of Open Access Journals (Sweden)

Abera Assefa

2015-08-01

Full Text Available Abstract Land degradation is the most chronic problem in the Ethiopia. Soil erosion and denudation of vegetation covers are tending to enlarge the area of degraded and west land in semi-arid watersheds. It is therefore watershed management is believed as a holistic approach to create a climate smart landscape that integrate forestry agriculture pasture and soil water management with an objective of sustainable management of natural resources to improve livelihood. This approach pursues to promote interactions among multiple stakeholders and their interests within and between the upstream and downstream locations of a watershed. Melkassa Agricultural Research Centre MARC has been implementing integrated watershed management research project in the Jogo-gudedo watershed from 2010-2014 and lessons from Jogo-gudedo watershed are presented in this research report. Participatory action research PAR was implemented on Soil and Water Conservation SWC area enclosure Agroforestry AF Conservation Tillage CT energy saving stove drought resistance crop varieties in the Jogo-gudedo watershed. Empirical research and action research at plot level and evaluation of introduced technologies with farmers through experimental learning approach and documentation were employed. The participatory evaluation and collective action of SWC and improved practices brought high degree of acceptance of the practices and technologies. This had been ratified by the implementation of comprehensive watershed management action research which in turn enabled to taste and exploit benefits of climate-smart agricultural practices. Eventually significant reduction on soil loss and fuel wood consumption improvements on vegetation cover and crop production were quantitatively recorded as a good indicator and success. Field visit meetings trainings and frequent dialogues between practitioners and communities at watershed level have had a help in promoting the climate smart agriculture

Adopt Your Watershed

Data.gov (United States)

U.S. Environmental Protection Agency — Adopt Your Watershed is a Website that encourages stewardship of the nation's water resources and serves as a national inventory of local watershed groups and...

Hydrogeologic setting and ground water flow beneath a section of Indian River Bay, Delaware

Science.gov (United States)

Krantz, David E.; Manheim, Frank T.; Bratton, John F.; Phelan, Daniel J.

2004-01-01

The small bays along the Atlantic coast of the Delmarva Peninsula (Delaware, Maryland, and Virginia) are a valuable natural resource, and an asset for commerce and recreation. These coastal bays also are vulnerable to eutrophication from the input of excess nutrients derived from agriculture and other human activities in the watersheds. Ground water discharge may be an appreciable source of fresh water and a transport pathway for nutrients entering the bays. This paper presents results from an investigation of the physical properties of the surficial aquifer and the processes associated with ground water flow beneath Indian River Bay, Delaware. A key aspect of the project was the deployment of a new technology, streaming horizontal resistivity, to map the subsurface distribution of fresh and saline ground water beneath the bay. The resistivity profiles showed complex patterns of ground water flow, modes of mixing, and submarine ground water discharge. Cores, gamma and electromagnetic-induction logs, and in situ ground water samples collected during a coring operation in Indian River Bay verified the interpretation of the resistivity profiles. The shore-parallel resistivity lines show subsurface zones of fresh ground water alternating with zones dominated by the flow of salt water from the estuary down into the aquifer. Advective flow produces plumes of fresh ground water 400 to 600 m wide and 20 m thick that may extend more than 1 km beneath the estuary. Zones of dispersive mixing between fresh and saline ground water develop on the upper, lower, and lateral boundaries of the the plume. the plumes generally underlie small incised valleys that can be traced landward to stream draining the upland. The incised valleys are filled with 1 to 2 m of silt and peat that act as a semiconfining layer to restrict the downward flow of salt water from the estuary. Active circulation of both the fresh and saline ground water masses beneath the bay is inferred from the geophysical

Distribution and behavior of major and trace elements in Tokyo Bay, Mutsu Bay and Funka Bay marine sediments

International Nuclear Information System (INIS)

Honda, Teruyuki; Kimura, Ken-ichiro

2003-01-01

Fourteen major and trace elements in marine sediment core samples collected from the coasts along eastern Japan, i.e. Tokyo Bay (II) (the recess), Tokyo Bay (IV) (the mouth), Mutsu Bay and Funka Bay and the Northwest Pacific basin as a comparative subject were determined by the instrumental neutron activation analysis (INAA). The sedimentation rates and sedimentary ages were calculated for the coastal sediment cores by the 210 Pb method. The results obtained in this study are summarized as follows: (1) Lanthanoid abundance patterns suggested that the major origin of the sediments was terrigenous material. La*/Lu* and Ce*/La* ratios revealed that the sediments from Tokyo Bay (II) and Mutsu Bay more directly reflected the contribution from river than those of other regions. In addition, the Th/Sc ratio indicated that the coastal sediments mainly originated in the materials from the volcanic island-arcs, Japanese islands, whereas those from the Northwest Pacific mainly from the continent. (2) The correlation between the Ce/U and Th/U ratios with high correlation coefficients of 0.920 to 0.991 indicated that all the sediments from Tokyo Bay (II) and Funka Bay were in reducing conditions while at least the upper sediments from Tokyo Bay (IV) and Mutsu Bay were in oxidizing conditions. (3) It became quite obvious that the sedimentation mechanism and the sedimentation environment at Tokyo Bay (II) was different from those at Tokyo Bay (IV), since the sedimentation rate at Tokyo Bay (II) was approximately twice as large as that at Tokyo Bay (IV). The sedimentary age of the 5th layer (8∼10 cm in depth) from Funka Bay was calculated at approximately 1940∼50, which agreed with the time, 1943∼45 when Showa-shinzan was formed by the eruption of the Usu volcano. (author)

Hydrological functions of a mine-impacted and natural peatland-dominated watershed, James Bay Lowland

OpenAIRE

Leclair, Melissa; Whittington, Pete; Price, Jonathan

2015-01-01

Study region: This study was conducted in Northern Ontario, Canada, in the middle of the Hudson-James Bay. Lowland: one of the world’s largest wetland complexes. Study focus: Northern latitudes are expected to be the most impacted by climate change in the next century and adding to this stressor are increased mineral exploration activities, such as the De Beers Victor Mine, a large open-pit diamond mine. Because of the extremely low relief and presence of marine sediments, horizontal runof...

The unnatural history of Kāne‘ohe Bay: coral reef resilience in the face of centuries of anthropogenic impacts

Directory of Open Access Journals (Sweden)

Keisha D. Bahr

2015-05-01

Full Text Available Kāneʻohe Bay, which is located on the on the NE coast of Oʻahu, Hawaiʻi, represents one of the most intensively studied estuarine coral reef ecosystems in the world. Despite a long history of anthropogenic disturbance, from early settlement to post European contact, the coral reef ecosystem of Kāneʻohe Bay appears to be in better condition in comparison to other reefs around the world. The island of Moku o Loʻe (Coconut Island in the southern region of the bay became home to the Hawaiʻi Institute of Marine Biology in 1947, where researchers have since documented the various aspects of the unique physical, chemical, and biological features of this coral reef ecosystem. The first human contact by voyaging Polynesians occurred at least 700 years ago. By A.D. 1250 Polynesians voyagers had settled inhabitable islands in the region which led to development of an intensive agricultural, fish pond and ocean resource system that supported a large human population. Anthropogenic disturbance initially involved clearing of land for agriculture, intentional or accidental introduction of alien species, modification of streams to supply water for taro culture, and construction of massive shoreline fish pond enclosures and extensive terraces in the valleys that were used for taro culture. The arrival by the first Europeans in 1778 led to further introductions of plants and animals that radically changed the landscape. Subsequent development of a plantation agricultural system led to increased human immigration, population growth and an end to traditional land and water management practices. The reefs were devastated by extensive dredge and fill operations as well as rapid growth of human population, which led to extensive urbanization of the watershed. By the 1960’s the bay was severely impacted by increased sewage discharge along with increased sedimentation due to improper grading practices and stream channelization, resulting in extensive loss of

The unnatural history of Kāne'ohe Bay: coral reef resilience in the face of centuries of anthropogenic impacts.

Science.gov (United States)

Bahr, Keisha D; Jokiel, Paul L; Toonen, Robert J

2015-01-01

Kāne'ohe Bay, which is located on the on the NE coast of O'ahu, Hawai'i, represents one of the most intensively studied estuarine coral reef ecosystems in the world. Despite a long history of anthropogenic disturbance, from early settlement to post European contact, the coral reef ecosystem of Kāne'ohe Bay appears to be in better condition in comparison to other reefs around the world. The island of Moku o Lo'e (Coconut Island) in the southern region of the bay became home to the Hawai'i Institute of Marine Biology in 1947, where researchers have since documented the various aspects of the unique physical, chemical, and biological features of this coral reef ecosystem. The first human contact by voyaging Polynesians occurred at least 700 years ago. By A.D. 1250 Polynesians voyagers had settled inhabitable islands in the region which led to development of an intensive agricultural, fish pond and ocean resource system that supported a large human population. Anthropogenic disturbance initially involved clearing of land for agriculture, intentional or accidental introduction of alien species, modification of streams to supply water for taro culture, and construction of massive shoreline fish pond enclosures and extensive terraces in the valleys that were used for taro culture. The arrival by the first Europeans in 1778 led to further introductions of plants and animals that radically changed the landscape. Subsequent development of a plantation agricultural system led to increased human immigration, population growth and an end to traditional land and water management practices. The reefs were devastated by extensive dredge and fill operations as well as rapid growth of human population, which led to extensive urbanization of the watershed. By the 1960's the bay was severely impacted by increased sewage discharge along with increased sedimentation due to improper grading practices and stream channelization, resulting in extensive loss of coral cover. The reefs of K�

An assessment of landscape characteristics affecting estuarine nitrogen loading in an urban watershed.

Science.gov (United States)

Yang, Xiaojun

2012-02-01

Exploring the quantitative association between landscape characteristics and the ecological conditions of receiving waters has recently become an emerging area for eco-environmental research. While the landscape-water relationship research has largely targeted on inland aquatic systems, there has been an increasing need to develop methods and techniques that can better work with coastal and estuarine ecosystems. In this paper, we present a geospatial approach to examine the quantitative relationship between landscape characteristics and estuarine nitrogen loading in an urban watershed. The case study site is in the Pensacola estuarine drainage area, home of the city of Pensacola, Florida, USA, where vigorous urban sprawling has prompted growing concerns on the estuarine ecological health. Central to this research is a remote sensor image that has been used to extract land use/cover information and derive landscape metrics. Several significant landscape metrics are selected and spatially linked with the nitrogen loading data for the Pensacola bay area. Landscape metrics and nitrogen loading are summarized by equal overland flow-length rings, and their association is examined by using multivariate statistical analysis. And a stepwise model-building protocol is used for regression designs to help identify significant variables that can explain much of the variance in the nitrogen loading dataset. It is found that using landscape composition or spatial configuration alone can explain most of the nitrogen loading variability. Of all the regression models using metrics derived from a single land use/cover class as the independent variables, the one from the low density urban gives the highest adjusted R-square score, suggesting the impact of the watershed-wide urban sprawl upon this sensitive estuarine ecosystem. Measures towards the reduction of non-point source pollution from urban development are necessary in the area to protect the Pensacola bay ecosystem and its

Spatial Predictive Modeling and Remote Sensing of Land Use Change in the Chesapeake Bay Watershed

Science.gov (United States)

Goetz, Scott J.; Bockstael, Nancy E.; Jantz, Claire A.

2005-01-01

This project was focused on modeling the processes by which increasing demand for developed land uses, brought about by changes in the regional economy and the socio-demographics of the region, are translated into a changing spatial pattern of land use. Our study focused on a portion of the Chesapeake Bay Watershed where the spatial patterns of sprawl represent a set of conditions generally prevalent in much of the U.S. Working in the region permitted us access to (i) a time-series of multi-scale and multi-temporal (including historical) satellite imagery and (ii) an established network of collaborating partners and agencies willing to share resources and to utilize developed techniques and model results. In addition, a unique parcel-level tax assessment database and linked parcel boundary maps exists for two counties in the Maryland portion of this region that made it possible to establish a historical cross-section time-series database of parcel level development decisions. Scenario analyses of future land use dynamics provided critical quantitative insight into the impact of alternative land management and policy decisions. These also have been specifically aimed at addressing growth control policies aimed at curbing exurban (sprawl) development. Our initial technical approach included three components: (i) spatial econometric modeling of the development decision, (ii) remote sensing of suburban change and residential land use density, including comparisons of past change from Landsat analyses and more traditional sources, and (iii) linkages between the two through variable initialization and supplementation of parcel level data. To these we added a fourth component, (iv) cellular automata modeling of urbanization, which proved to be a valuable addition to the project. This project has generated both remote sensing and spatially explicit socio-economic data to estimate and calibrate the parameters for two different types of land use change models and has

The role of interior watershed processes in improving parameter estimation and performance of watershed models.

Science.gov (United States)

Yen, Haw; Bailey, Ryan T; Arabi, Mazdak; Ahmadi, Mehdi; White, Michael J; Arnold, Jeffrey G

2014-09-01

Watershed models typically are evaluated solely through comparison of in-stream water and nutrient fluxes with measured data using established performance criteria, whereas processes and responses within the interior of the watershed that govern these global fluxes often are neglected. Due to the large number of parameters at the disposal of these models, circumstances may arise in which excellent global results are achieved using inaccurate magnitudes of these "intra-watershed" responses. When used for scenario analysis, a given model hence may inaccurately predict the global, in-stream effect of implementing land-use practices at the interior of the watershed. In this study, data regarding internal watershed behavior are used to constrain parameter estimation to maintain realistic intra-watershed responses while also matching available in-stream monitoring data. The methodology is demonstrated for the Eagle Creek Watershed in central Indiana. Streamflow and nitrate (NO) loading are used as global in-stream comparisons, with two process responses, the annual mass of denitrification and the ratio of NO losses from subsurface and surface flow, used to constrain parameter estimation. Results show that imposing these constraints not only yields realistic internal watershed behavior but also provides good in-stream comparisons. Results further demonstrate that in the absence of incorporating intra-watershed constraints, evaluation of nutrient abatement strategies could be misleading, even though typical performance criteria are satisfied. Incorporating intra-watershed responses yields a watershed model that more accurately represents the observed behavior of the system and hence a tool that can be used with confidence in scenario evaluation. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Human-induced river runoff overlapping natural climate variability over the last 150 years: Palynological evidence (Bay of Brest, NW France)

Science.gov (United States)

Lambert, Clément; Penaud, Aurélie; Vidal, Muriel; Klouch, Khadidja; Gregoire, Gwendoline; Ehrhold, Axel; Eynaud, Frédérique; Schmidt, Sabine; Ragueneau, Olivier; Siano, Raffaele

2018-01-01

For the first time a very high resolution palynological study (mean resolution of 1 to 5 years) was carried out over the last 150 years in a French estuarine environment (Bay of Brest; NW France), allowing direct comparison between the evolution of landscapes, surface water, and human practices on Bay of Brest watersheds, through continental (especially pollen grains) and marine (phytoplanktonic microalgae: cysts of dinoflagellates or dinocysts) microfossils. Thanks to the small size of the watersheds and the close proximity of the depositional environment to the mainland, the Bay of Brest represents an ideal case study for palynological investigations. Palynological data were then compared to published palaeo-genetic analyses conducted on the same core and to various available instrumental data, allowing us to better characterize past environmental variability since the second half of the 19th century in Western Brittany. We provide evidence of some clues of recent eutrophication and/or pollution that affected phytoplankton communities and which appears linked with increased runoff (higher precipitations, higher percentages of riparian forest pollen, decline of salt marsh-type indicators, and higher values of the XRF Ti/Ca signal), mainly explained by the evolution of agricultural practices since 1945 superimposed on the warming climate trend. We assume that the significant relay observed between dinocyst taxa: Lingulodinium machaerophorum and Spiniferites bentorii around 1965 then followed by Spiniferites membranaceus after 1985, attests to a strong and recent eutrophication of Bay of Brest surface waters induced by high river runoff combined with abnormally elevated air temperatures, especially obvious in the data from 1990. The structure of the dinocyst community has thus been deeply altered, accompanied by an unprecedented increase of Alexandrium minutum toxic form at the same period, as confirmed by the genetic quantification. Despite this recent major

Watershed Fact Sheet: Improving Utah's Water Quality, Upper Bear River Watershed

OpenAIRE

Extension, USU

2012-01-01

The Upper Watershed of the Bear River Basin extends from the river's headwaters to Pixley Dam in Wyoming. This is the largest watershed in the Bear River Basin, with an area of about 2,000 square miles.

Integrating Federal and State data records to report progress in establishing agricultural conservation practices on Chesapeake Bay farms

Science.gov (United States)

Hively, W. Dean; Devereux, Olivia H.; Claggett, Peter

2013-01-01

In response to the Executive Order for Chesapeake Bay Protection and Restoration (E.O. #13508, May 12, 2009), the U.S. Geological Survey (USGS) took on the task of acquiring and assessing agricultural conservation practice data records for U.S. Department of Agriculture (USDA) programs, and transferred those datasets in aggregated format to State jurisdictional agencies for use in reporting conservation progress to the Chesapeake Bay Program Partnership (CBP Partnership). Under the guidelines and regulations that have been developed to protect and restore water-quality in the Chesapeake Bay, the six State jurisdictions that fall within the Chesapeake Bay watershed are required to report their progress in promoting agricultural conservation practices to the CBP Partnership on an annual basis. The installation and adoption of agricultural best management practices is supported by technical and financial assistance from both Federal and State conservation programs. The farm enrollment data for USDA conservation programs are confidential, but agencies can obtain access to the privacy-protected data if they are established as USDA Conservation Cooperators. The datasets can also be released to the public if they are first aggregated to protect farmer privacy. In 2012, the USGS used its Conservation Cooperator status to obtain implementation data for conservation programs sponsored by the USDA Natural Resources Conservation Service (NRCS) and the USDA Farm Service Agency (FSA) for farms within the Chesapeake Bay watershed. Three jurisdictions (Delaware, Pennsylvania, and West Virginia) used the USGS-provided aggregated dataset to report conservation progress in 2012, whereas the remaining three jurisdictions (Maryland, New York, and Virginia) used jurisdictional Conservation Cooperator Agreements to obtain privacy-protected data directly from the USDA. This report reviews the status of conservation data sharing between the USDA and the various jurisdictions, discusses the

Humic Substances from Manila Bay and Bolinao Bay Sediments

Directory of Open Access Journals (Sweden)

Elma Llaguno

1997-12-01

Full Text Available The C,H,N composition of sedimentary humic acids (HA extracted from three sites in Manila Bay and six sites in Bolinao Bay yielded H/C atomic ratios of 1.1-1.4 and N/C atomic ratios of 0.09 - 0.16. The Manila Bay HA's had lower H/C and N/C ratios compared to those from Bolinao Bay. The IR spectra showed prominent aliphatic C-H and amide I and II bands. Manila Bay HA's also had less diverse molecular composition based on the GC-MS analysis of the CuO and alkaline permanganate oxidation products of the humic acids.

The competing impacts of climate change and nutrient reductions on dissolved oxygen in Chesapeake Bay

Science.gov (United States)

Irby, Isaac D.; Friedrichs, Marjorie A. M.; Da, Fei; Hinson, Kyle E.

2018-05-01

The Chesapeake Bay region is projected to experience changes in temperature, sea level, and precipitation as a result of climate change. This research uses an estuarine-watershed hydrodynamic-biogeochemical modeling system along with projected mid-21st-century changes in temperature, freshwater flow, and sea level rise to explore the impact climate change may have on future Chesapeake Bay dissolved-oxygen (DO) concentrations and the potential success of nutrient reductions in attaining mandated estuarine water quality improvements. Results indicate that warming bay waters will decrease oxygen solubility year-round, while also increasing oxygen utilization via respiration and remineralization, primarily impacting bottom oxygen in the spring. Rising sea level will increase estuarine circulation, reducing residence time in bottom waters and increasing stratification. As a result, oxygen concentrations in bottom waters are projected to increase, while oxygen concentrations at mid-depths (3 < DO < 5 mg L-1) will typically decrease. Changes in precipitation are projected to deliver higher winter and spring freshwater flow and nutrient loads, fueling increased primary production. Together, these multiple climate impacts will lower DO throughout the Chesapeake Bay and negatively impact progress towards meeting water quality standards associated with the Chesapeake Bay Total Maximum Daily Load. However, this research also shows that the potential impacts of climate change will be significantly smaller than improvements in DO expected in response to the required nutrient reductions, especially at the anoxic and hypoxic levels. Overall, increased temperature exhibits the strongest control on the change in future DO concentrations, primarily due to decreased solubility, while sea level rise is expected to exert a small positive impact and increased winter river flow is anticipated to exert a small negative impact.

Effects of Land-Use Change on Characteristics and Dynamics of Watershed Discharges in Babeldaob, Palau, Micronesia

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Yimnang Golbuu

2011-01-01

Full Text Available This study assessed the impacts of differing levels of land development in four watersheds in Palau on river sediment yield and on sedimentation and turbidity. Area corrected sediment yield was strongly related to land development (r2=0.96, P=0.02, varying from 9.7 to 216 tons km−2 yr−1 between the least and most developed watershed. Mean sedimentation rates on reefs ranged from 0.7 to 46 mg cm−2 d−1, and mean turbidity ranged from 9 to 139 mg l−1. The higher values exceeded those known to harm corals. Because Palau's watersheds and estuaries are small, river floods were short-lived (typically lasting less than a day and the estuaries adjusted just as quickly to a number of different estuarine circulation patterns that, in turn, generated a large variability in the export of riverine fine sediment to the reefs. The ultimate fate of the fine sediment deposited on the reefs depended on wind resuspension, local currents, and geomorphology (whether the bay was open or semi-enclosed. Palau's small estuaries were generally not as effective as bigger estuaries in trapping sediments and thus at sheltering the reefs. Therefore, greater efforts are needed to control and mitigate land activities that contribute to the increase in sediment yield.

Radiocarbon dating, chronologic framework, and changes in accumulation rates of holocene estuarine sediments from Chesapeake Bay

Science.gov (United States)

Colman, Steven M.; Baucom, P.C.; Bratton, J.F.; Cronin, T. M.; McGeehin, J.P.; Willard, D.; Zimmerman, A.R.; Vogt, P.R.

2002-01-01

Rapidly accumulating Holocene sediments in estuaries commonly are difficult to sample and date. In Chesapeake Bay, we obtained sediment cores as much as 20 m in length and used numerous radiocarbon ages measured by accelarator mass spectrometry methods to provide the first detailed chronologies of Holocene sediment accumulation in the bay. Carbon in these sediments is a complex mixture of materials from a variety of sources. Analyses of different components of the sediments show that total organic carbon ages are largely unreliable, because much of the carbon (including coal) has been transported to the bay from upstream sources and is older than sediments in which it was deposited. Mollusk shells (clams, oysters) and foraminifera appear to give reliable results, although reworking and burrowing are potential problems. Analyses of museum specimens collected alive before atmospheric nuclear testing suggest that the standard reservoir correction for marine samples is appropriate for middle to lower Chesapeake Bay. The biogenic carbonate radiocarbon ages are compatible with 210 Pb and 137 Cs data and pollen stratigraphy from the same sites. Post-settlement changes in sediment transport and accumulation is an important environmental issue in many estuaries, including the Chesapeake. Our data show that large variations in sediment mass accumulation rates occur among sites. At shallow water sites, local factors seem to control changes in accumulation rates with time. Our two relatively deep-water sites in the axial channel of the bay have different long-term average accumulation rates, but the history of sediment accumulation at these sites appears to reflect overall conditions in the bay. Mass accumulation rates at the two deep-water sites rapidly increased by about fourfold coincident with widespread land clearance for agriculture in the Chesapeake watershed.

EPA's Review of Concentrated Animal Feeding Operation (CAFO) Permits and Nutrient Management Plans in the Chesapeake Bay Watershed

Science.gov (United States)

Starting in 2013, EPA conducted reviews of Concentrated Animal Feeding Operations (CAFOs) permits and nutrient management plans (NMPs) in six of the Bay jurisdictions (Delaware, Maryland, New York, Pennsylvania, Virginia and West Virginia).

Empirical models based on the universal soil loss equation fail to predict sediment discharges from Chesapeake Bay catchments.

Science.gov (United States)

Boomer, Kathleen B; Weller, Donald E; Jordan, Thomas E

2008-01-01

The Universal Soil Loss Equation (USLE) and its derivatives are widely used for identifying watersheds with a high potential for degrading stream water quality. We compared sediment yields estimated from regional application of the USLE, the automated revised RUSLE2, and five sediment delivery ratio algorithms to measured annual average sediment delivery in 78 catchments of the Chesapeake Bay watershed. We did the same comparisons for another 23 catchments monitored by the USGS. Predictions exceeded observed sediment yields by more than 100% and were highly correlated with USLE erosion predictions (Pearson r range, 0.73-0.92; p USLE estimates (r = 0.87; p USLE model did not change the results. In ranked comparisons between observed and predicted sediment yields, the models failed to identify catchments with higher yields (r range, -0.28-0.00; p > 0.14). In a multiple regression analysis, soil erodibility, log (stream flow), basin shape (topographic relief ratio), the square-root transformed proportion of forest, and occurrence in the Appalachian Plateau province explained 55% of the observed variance in measured suspended sediment loads, but the model performed poorly (r(2) = 0.06) at predicting loads in the 23 USGS watersheds not used in fitting the model. The use of USLE or multiple regression models to predict sediment yields is not advisable despite their present widespread application. Integrated watershed models based on the USLE may also be unsuitable for making management decisions.

THE BEAR BROOK WATERSHED MANIPULATION PROJECT: WATERSHED SCIENCE IN A POLICY PERSPECTIVE

Science.gov (United States)

The Bear Brook Watershed Manipulation in Maine is a paired watershed experiment. Monitoring of the paired catchments (East Bear Brook - reference; West Bear Brook - experimental) began in early 1987. Chemical manipulation of West Bear Brook catchment began in November 1989. Proce...

Integration of bed characteristics, geochemical tracers, current measurements, and numerical modeling for assessing the provenance of beach sand in the San Francisco Bay Coastal System

Science.gov (United States)

Barnard, Patrick L.; Foxgrover, Amy C.; Elias, Edwin P.L.; Erikson, Li H.; Hein, James R.; McGann, Mary; Mizell, Kira; Rosenbauer, Robert J.; Swarzenski, Peter W.; Takesue, Renee K.; Wong, Florence L.; Woodrow, Donald L.; Barnard, P.L.; Jaffee, B.E.; Schoellhamer, D.H.

2013-01-01

Over 150 million m3 of sand-sized sediment has disappeared from the central region of the San Francisco Bay Coastal System during the last half century. This enormous loss may reflect numerous anthropogenic influences, such as watershed damming, bay-fill development, aggregate mining, and dredging. The reduction in Bay sediment also appears to be linked to a reduction in sediment supply and recent widespread erosion of adjacent beaches, wetlands, and submarine environments. A unique, multi-faceted provenance study was performed to definitively establish the primary sources, sinks, and transport pathways of beach-sized sand in the region, thereby identifying the activities and processes that directly limit supply to the outer coast. This integrative program is based on comprehensive surficial sediment sampling of the San Francisco Bay Coastal System, including the seabed, Bay floor, area beaches, adjacent rock units, and major drainages. Analyses of sample morphometrics and biological composition (e.g., Foraminifera) were then integrated with a suite of tracers including 87Sr/86Sr and 143Nd/144Nd isotopes, rare earth elements, semi-quantitative X-ray diffraction mineralogy, and heavy minerals, and with process-based numerical modeling, in situ current measurements, and bedform asymmetry to robustly determine the provenance of beach-sized sand in the region.

The competing impacts of climate change and nutrient reductions on dissolved oxygen in Chesapeake Bay

Directory of Open Access Journals (Sweden)

I. D. Irby

2018-05-01

Full Text Available The Chesapeake Bay region is projected to experience changes in temperature, sea level, and precipitation as a result of climate change. This research uses an estuarine-watershed hydrodynamic–biogeochemical modeling system along with projected mid-21st-century changes in temperature, freshwater flow, and sea level rise to explore the impact climate change may have on future Chesapeake Bay dissolved-oxygen (DO concentrations and the potential success of nutrient reductions in attaining mandated estuarine water quality improvements. Results indicate that warming bay waters will decrease oxygen solubility year-round, while also increasing oxygen utilization via respiration and remineralization, primarily impacting bottom oxygen in the spring. Rising sea level will increase estuarine circulation, reducing residence time in bottom waters and increasing stratification. As a result, oxygen concentrations in bottom waters are projected to increase, while oxygen concentrations at mid-depths (3 < DO < 5 mg L−1 will typically decrease. Changes in precipitation are projected to deliver higher winter and spring freshwater flow and nutrient loads, fueling increased primary production. Together, these multiple climate impacts will lower DO throughout the Chesapeake Bay and negatively impact progress towards meeting water quality standards associated with the Chesapeake Bay Total Maximum Daily Load. However, this research also shows that the potential impacts of climate change will be significantly smaller than improvements in DO expected in response to the required nutrient reductions, especially at the anoxic and hypoxic levels. Overall, increased temperature exhibits the strongest control on the change in future DO concentrations, primarily due to decreased solubility, while sea level rise is expected to exert a small positive impact and increased winter river flow is anticipated to exert a small negative impact.

Investigation of aquifer-estuary interaction using wavelet analysis of fiber-optic temperature data

Science.gov (United States)

Henderson, R.D.; Day-Lewis, Frederick D.; Harvey, Charles F.

2009-01-01

Fiber-optic distributed temperature sensing (FODTS) provides sub-minute temporal and meter-scale spatial resolution over kilometer-long cables. Compared to conventional thermistor or thermocouple-based technologies, which measure temperature at discrete (and commonly sparse) locations, FODTS offers nearly continuous spatial coverage, thus providing hydrologic information at spatiotemporal scales previously impossible. Large and information-rich FODTS datasets, however, pose challenges for data exploration and analysis. To date, FODTS analyses have focused on time-series variance as the means to discriminate between hydrologic phenomena. Here, we demonstrate the continuous wavelet transform (CWT) and cross-wavelet transform (XWT) to analyze FODTS in the context of related hydrologic time series. We apply the CWT and XWT to data from Waquoit Bay, Massachusetts to identify the location and timing of tidal pumping of submarine groundwater.

Applying soil property information for watershed assessment.

Science.gov (United States)

Archer, V.; Mayn, C.; Brown, S. R.

2017-12-01

The Forest Service uses a priority watershed scheme to guide where to direct watershed restoration work. Initial assessment was done across the nation following the watershed condition framework process. This assessment method uses soils information for a three step ranking across each 12 code hydrologic unit; however, the soil information used in the assessment may not provide adequate detail to guide work on the ground. Modern remote sensing information and terrain derivatives that model the environmental gradients hold promise of showing the influence of soil forming factors on watershed processes. These small scale data products enable the disaggregation of coarse scale soils mapping to show continuous soil property information across a watershed. When this information is coupled with the geomorphic and geologic information, watershed specialists can more aptly understand the controlling influences of drainage within watersheds and focus on where watershed restoration projects can have the most success. A case study on the application of this work shows where road restoration may be most effective.

33 CFR 100.919 - International Bay City River Roar, Bay City, MI.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false International Bay City River Roar, Bay City, MI. 100.919 Section 100.919 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF... Bay City River Roar, Bay City, MI. (a) Regulated Area. A regulated area is established to include all...

Adaptive Management Fitness of Watersheds

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Ignacio Porzecanski

2012-09-01

Full Text Available Adaptive management (AM promises to improve our ability to cope with the inherent uncertainties of managing complex dynamic systems such as watersheds. However, despite the increasing adherence and attempts at implementation, the AM approach is rarely successful in practice. A one-size-fits-all AM strategy fails because some watersheds are better positioned at the outset to succeed at AM than others. We introduce a diagnostic tool called the Index of Management Condition (IMC and apply it to twelve diverse watersheds in order to determine their AM "fitness"; that is, the degree to which favorable adaptive management conditions are in place in a watershed.

Watershed Watch: Using undergraduate student-driven inquiry-based research projects as a means of engaging undeclared students in the biogeosciences

Science.gov (United States)

Rock, B. N.; Hale, S.; Graham, K.; Hayden, L. B.

2009-12-01

Watershed Watch (NSF 0525433) engages early undergraduate students from two-year and four-year colleges in student-driven full inquiry-based instruction in the biogeosciences. Program goals for Watershed Watch are to test if inquiry-rich student-driven projects sufficiently engage undeclared students (or noncommittal STEM majors) to declare a STEM major (or remain with their STEM major). The program is a partnership between two four-year campuses - the University of New Hampshire (UNH), and Elizabeth City State University (ECSU, in North Carolina); and two two-year campuses - Great Bay Community College (GBCC, in New Hampshire) and the College of the Albemarle (COA, in North Carolina). The program focuses on two watersheds: the Merrimack Ricer Watershed in New Hampshire and Massachusetts, and the Pasquotank River Watershed in Virginia and North Carolina. Both the terrestrial and aquatic components of both watersheds are evaluated using the student-driven projects. A significant component of this program is an intensive two-week Summer Research Institute (SRI), in which undeclared freshmen and sophomores investigate various aspects of their local watershed. Two Summer Research Institutes have been held on the UNH campus (2006 and 2008) and two on the ECSU campus (2007 and 2009). Students develop their own research questions and study design, collect and analyze data, and produce a scientific oral or poster presentation on the last day of the SRI. The course objectives, curriculum and schedule are presented as a model for dissemination for other institutions and programs seeking to develop inquiry-rich programs or courses designed to attract students into biogeoscience disciplines. Data from self-reported student feedback indicate the most important factors explaining high-levels of student motivation and research excellence in the program are: 1) working with committed, energetic, and enthusiastic faculty mentors, and 2) faculty mentors demonstrating high degrees of

A Watershed Integrity Definition and Assessment Approach to Support Strategic Management of Watersheds

Science.gov (United States)

Although defined hydrologically as a drainage basin, watersheds are systems that physically link the individual social and ecological attributes that comprise them. Hence the structure, function, and feedback systems of watersheds are dependent on interactions between these soci...

Development, evaluation, and application of sediment quality targets for assessing and managing contaminated sediments in Tampa Bay, Florida

Science.gov (United States)

MacDonald, D.D.; Carr, R.S.; Eckenrod, D.; Greening, H.; Grabe, S.; Ingersoll, C.G.; Janicki, S.; Janicki, T.; Lindskoog, R.A.; Long, E.R.; Pribble, R.; Sloane, G.; Smorong, D.E.

2004-01-01

Tampa Bay is a large, urban estuary that is located in west central Florida. Although water quality conditions represent an important concern in this estuary, information from numerous sources indicates that sediment contamination also has the potential to adversely affect aquatic organisms, aquatic-dependent wildlife, and human health. As such, protecting relatively uncontaminated areas of the bay from contamination and reducing the amount of toxic chemicals in contaminated sediments have been identified as high-priority sediment management objectives for Tampa Bay. To address concerns related to sediment contamination in the bay, an ecosystem-based framework for assessing and managing sediment quality conditions was developed that included identification of sediment quality issues and concerns, development of ecosystem goals and objectives, selection of ecosystem health indicators, establishment of metrics and targets for key indicators, and incorporation of key indicators, metrics, and targets into watershed management plans and decision-making processes. This paper describes the process that was used to select and evaluate numerical sediment quality targets (SQTs) for assessing and managing contaminated sediments. These SQTs included measures of sediment chemistry, whole-sediment and pore-water toxicity, and benthic invertebrate community structure. In addition, the paper describes how the SQTs were used to develop site-specific concentration-response models that describe how the frequency of adverse biological effects changes with increasing concentrations of chemicals of potential concern. Finally, a key application of the SQTs for defining sediment management areas is discussed.

Evaluating watershed protection programs in New York City's Cannonsville Reservoir source watershed using SWAT-HS

Science.gov (United States)

Hoang, L.; Mukundan, R.; Moore, K. E.; Owens, E. M.; Steenhuis, T. S.

2017-12-01

New York City (NYC)'s reservoirs supply over one billion gallons of drinking water each day to over nine million consumers in NYC and upstate communities. The City has invested more than $1.5 billion in watershed protection programs to maintain a waiver from filtration for the Catskill and Delaware Systems. In the last 25 years, the NYC Department of Environmental Protection (NYCDEP) has implemented programs in cooperation with upstate communities that include nutrient management, crop rotations, improvement of barnyards and manure storage, implementing tertiary treatment for Phosphorus (P) in wastewater treatment plants, and replacing failed septic systems in an effort to reduce P loads to water supply reservoirs. There have been several modeling studies evaluating the effect of agricultural Best Management Practices (BMPs) on P control in the Cannonsville watershed in the Delaware System. Although these studies showed that BMPs would reduce dissolved P losses, they were limited to farm-scale or watershed-scale estimates of reduction factors without consideration of the dynamic nature of overland flow and P losses from variable source areas. Recently, we developed the process-based SWAT-Hillslope (SWAT-HS) model, a modified version of the Soil and Water Assessment Tool (SWAT) that can realistically predict variable source runoff processes. The objective of this study is to use the SWAT-HS model to evaluate watershed protection programs addressing both point and non-point sources of P. SWAT-HS predicts streamflow very well for the Cannonsville watershed with a daily Nash Sutcliffe Efficiency (NSE) of 0.85 at the watershed outlet and NSE values ranging from 0.56 - 0.82 at five other locations within the watershed. Based on good hydrological prediction, we applied the model to predict P loads using detailed P inputs that change over time due to the implementation of watershed protection programs. Results from P model predictions provide improved projections of P

Application of a Weighted Regression Model for Reporting Nutrient and Sediment Concentrations, Fluxes, and Trends in Concentration and Flux for the Chesapeake Bay Nontidal Water-Quality Monitoring Network, Results Through Water Year 2012

Science.gov (United States)

Chanat, Jeffrey G.; Moyer, Douglas L.; Blomquist, Joel D.; Hyer, Kenneth E.; Langland, Michael J.

2016-01-13

In the Chesapeake Bay watershed, estimated fluxes of nutrients and sediment from the bay’s nontidal tributaries into the estuary are the foundation of decision making to meet reductions prescribed by the Chesapeake Bay Total Maximum Daily Load (TMDL) and are often the basis for refining scientific understanding of the watershed-scale processes that influence the delivery of these constituents to the bay. Two regression-based flux and trend estimation models, ESTIMATOR and Weighted Regressions on Time, Discharge, and Season (WRTDS), were compared using data from 80 watersheds in the Chesapeake Bay Nontidal Water-Quality Monitoring Network (CBNTN). The watersheds range in size from 62 to 70,189 square kilometers and record lengths range from 6 to 28 years. ESTIMATOR is a constant-parameter model that estimates trends only in concentration; WRTDS uses variable parameters estimated with weighted regression, and estimates trends in both concentration and flux. WRTDS had greater explanatory power than ESTIMATOR, with the greatest degree of improvement evident for records longer than 25 years (30 stations; improvement in median model R2= 0.06 for total nitrogen, 0.08 for total phosphorus, and 0.05 for sediment) and the least degree of improvement for records of less than 10 years, for which the two models performed nearly equally. Flux bias statistics were comparable or lower (more favorable) for WRTDS for any record length; for 30 stations with records longer than 25 years, the greatest degree of improvement was evident for sediment (decrease of 0.17 in median statistic) and total phosphorus (decrease of 0.05). The overall between-station pattern in concentration trend direction and magnitude for all constituents was roughly similar for both models. A detailed case study revealed that trends in concentration estimated by WRTDS can operationally be viewed as a less-constrained equivalent to trends in concentration estimated by ESTIMATOR. Estimates of annual mean flow

Mute swans and their Chesapeake Bay habitats: proceedings of a symposium

Science.gov (United States)

Perry, M.C.

2004-01-01

The symposium 'Mute Swans and their Chesapeake Bay Habitats,' held on June 7, 2001, provided a forum for biologists and managers to share research findings and management ideas concerning the exotic and invasive mute swan (Cygnus olar). This species has been increasing in population size and is considered by many to be a problem in regard to natural food resources in the Bay that are used by native waterfowl during the winter months. Other persons, however, feel that resource managers are attempting to create a problem to justify more killing of waterfowl by hunters. Some persons also believe that managers should focus on the larger issues causing the decline of native food resources, such as the unabated human population increase in the Bay watershed and in the immediate coastal areas of the Bay. The symposium, sponsored by the Wildfowl Trust of North America and the U.S. Geological Survey, provided the atmosphere for presentation of mute swan data and opinions in a collegial setting where discussion was welcomed and was often informative and enthusiastic. An interesting historic review of the swan in regard to the history of mankind was presented, followed by a discussion on the positive and negative effects of invasive species. Biologists from different parts of the continent discussed the population status of the species in several states in the east and in the Great Lakes area. Data on the food habits of this species were presented in regard to submerged aquatic vegetation, and an interesting discussion on the role that the food habits of Canada geese in regard to native vegetation was presented. Findings and recommendations of the Mute Swan Task Force were presented. Finally, a representative of the Friends of Animals gave a thought-provoking presentation in defense of the mute swan. The presentations, in general, provided the necessary information and recommendations to allow managers to proceed with management of this controversial species with new and

Fena Valley Reservoir watershed and water-balance model updates and expansion of watershed modeling to southern Guam

Science.gov (United States)

Rosa, Sarah N.; Hay, Lauren E.

2017-12-01

In 2014, the U.S. Geological Survey, in cooperation with the U.S. Department of Defense’s Strategic Environmental Research and Development Program, initiated a project to evaluate the potential impacts of projected climate-change on Department of Defense installations that rely on Guam’s water resources. A major task of that project was to develop a watershed model of southern Guam and a water-balance model for the Fena Valley Reservoir. The southern Guam watershed model provides a physically based tool to estimate surface-water availability in southern Guam. The U.S. Geological Survey’s Precipitation Runoff Modeling System, PRMS-IV, was used to construct the watershed model. The PRMS-IV code simulates different parts of the hydrologic cycle based on a set of user-defined modules. The southern Guam watershed model was constructed by updating a watershed model for the Fena Valley watersheds, and expanding the modeled area to include all of southern Guam. The Fena Valley watershed model was combined with a previously developed, but recently updated and recalibrated Fena Valley Reservoir water-balance model.Two important surface-water resources for the U.S. Navy and the citizens of Guam were modeled in this study; the extended model now includes the Ugum River watershed and improves upon the previous model of the Fena Valley watersheds. Surface water from the Ugum River watershed is diverted and treated for drinking water, and the Fena Valley watersheds feed the largest surface-water reservoir on Guam. The southern Guam watershed model performed “very good,” according to the criteria of Moriasi and others (2007), in the Ugum River watershed above Talofofo Falls with monthly Nash-Sutcliffe efficiency statistic values of 0.97 for the calibration period and 0.93 for the verification period (a value of 1.0 represents perfect model fit). In the Fena Valley watershed, monthly simulated streamflow volumes from the watershed model compared reasonably well with the

Correlation and Fishers’ Perception in Selected Sites in Laguna de Bay, Luzon Island, Philippines

Directory of Open Access Journals (Sweden)

Arthur J. Lagbas

2017-01-01

Full Text Available White goby (Glossogobius giuris Hamilton 1822 is an omnivorous, native fish species which can be found in Laguna de Bay and its tributaries, and in other bodies of water in the Philippines. Deteriorating water quality, unsustainable fishing practices, aquaculture and predation by introduced invasive species are threatening the population of white goby and other native fish species in Laguna de Bay. This study was conducted to correlate select physico-chemical parameters of lake water and zooplankton abundance, and to assess white goby population based on fishers’ perception. Water samples were collected in three sites in June, September and December 2014. Twenty one zooplankton species belonging to 12 families were identified. The most abundant and frequently encountered zooplankton species is Eurytemora affinis Poppe 1880. Zooplanktons were most abundant in June and lowest in September. Key informant interviews with local fishers revealed that white goby population was abundant in April to August while catch report showed that fish catch is abundant in June and least during December. The fish abundance in April to June could be attributed to high productivity especially in summer season. The fishers perceived that the population of white goby was declining mainly due to water pollution, aquaculture, and predation by invasive alien species. A multi-stakeholder sustainable watershed management should be adapted to improve the water quality and extinction of native fish species in Laguna de Bay.

77 FR 2972 - Thunder Bay Power Company, Thunder Bay Power, LLC, et al.

Science.gov (United States)

2012-01-20

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Thunder Bay Power Company, Thunder Bay Power, LLC, et al.; Notice of Application for Transfer of Licenses, and Soliciting Comments and Motions To Intervene Thunder Bay Power Company Project No. 2404-095 Thunder Bay Power, LLC Midwest Hydro, Inc...

Toward Understanding Mechanisms Controlling Urea Delivery in a Coastal Plain Watershed

Science.gov (United States)

Tzilkowski, S. S.; Buda, A. R.; Boyer, E. W.; Bryant, R. B.; May, E. B.

2012-12-01

Improved understanding of nutrient mobilization and delivery to surface waters is critical to protecting water quality in agricultural watersheds. Urea, a form of organic nitrogen, is a common nutrient found in fertilizers, manures, and human waste, and is gaining recognition as an important driver of coastal eutrophication, particularly through the development of harmful algal blooms. While several studies have documented elevated urea concentrations in tributaries draining to the Chesapeake Bay, little is known about the potential sources and flow pathways responsible for urea delivery from the landscape to surface waters, as well as how these sources and pathways might vary with changing seasons, antecedent conditions, and storm types. In this study, we investigated hydrologic controls on urea delivery in the Manokin River watershed through the analysis of urea concentration dynamics and hysteresis patterns during seven storm events that occurred in 2010 and 2011. The Manokin River is a Coastal Plain watershed (11.1 km2) on the Delmarva Peninsula that drains directly to the Chesapeake Bay and is characterized by extensive rural development coupled with intensive agriculture, particularly poultry production. Sampling was conducted through monthly grab sampling at baseflow conditions and by time-weighted, automated (Sigma) samplers during stormflow events. Monitored storms were chosen to represent a spectrum of antecedent conditions based on precipitation and groundwater levels in the area. Flushing from the landscape during events was found to be the predominant urea delivery mechanism, as urea concentrations increased 3-9 times above baseflow concentrations during storms. The timing and number of flushes, as well as the degree of increased concentrations were dependent on antecedent conditions and the characteristics of the storm event. For instance, during an intense (13.7 mm hr-1), short-duration (4 hrs) storm in August of 2010 when antecedent conditions were

Long-Term Changes in Sediment and Nutrient Delivery from Conowingo Dam to Chesapeake Bay: Effects of Reservoir Sedimentation.

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Zhang, Qian; Hirsch, Robert M; Ball, William P

2016-02-16

Reduction of suspended sediment (SS), total phosphorus (TP), and total nitrogen is an important focus for Chesapeake Bay watershed management. The Susquehanna River, the bay's largest tributary, has drawn attention because SS loads from behind Conowingo Dam (near the river's mouth) have been rising dramatically. To better understand these changes, we evaluated histories of concentration and loading (1986-2013) using data from sites above and below Conowingo Reservoir. First, observed concentration-discharge relationships show that SS and TP concentrations at the reservoir inlet have declined under most discharges in recent decades, but without corresponding declines at the outlet, implying recently diminished reservoir trapping. Second, best estimates of mass balance suggest decreasing net deposition of SS and TP in recent decades over a wide range of discharges, with cumulative mass generally dominated by the 75∼99.5th percentile of daily Conowingo discharges. Finally, stationary models that better accommodate effects of riverflow variability also support the conclusion of diminished trapping of SS and TP under a range of discharges that includes those well below the literature-reported scour threshold. Overall, these findings suggest that decreased net deposition of SS and TP has occurred at subscour levels of discharge, which has significant implications for the Chesapeake Bay ecosystem.

An Approach to Understanding Complex Socio-Economic Impacts and Responses to Climate Disruption in the Chesapeake Bay Region

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Schaefer, R. K.; Nix, M.; Ihde, A. G.; Paxton, L. J.; Weiss, M.; Simpkins, S.; Fountain, G. H.; APl GAIA Team

2011-12-01

In this paper we describe the application of a proven methodology for modeling the complex social and economic interactions of a system under stress to the regional issues that are tied to global climate disruption. Under the auspices of the GAIA project (http://gaia.jhuapl.edu), we have investigated simulating the complex interplay between climate, politics, society, industry, and the environment in the Chesapeake Bay Watershed and associated geographic areas of Maryland, Virginia, and Pennsylvania. This Chesapeake Bay simulation draws on interrelated geophysical and climate models to support decision-making analysis about the Bay. In addition to physical models, however, human activity is also incorporated via input and output calculations. For example, policy implications are modeled in relation to business activities surrounding fishing, farming, industry and manufacturing, land development, and tourism. This approach fosters collaboration among subject matter experts to advance a more complete understanding of the regional impacts of climate change. Simulated interactive competition, in which teams of experts are assigned conflicting objectives in a controlled environment, allow for subject exploration which avoids trivial solutions that neglect the possible responses of affected parties. Results include improved planning, the anticipation of areas of conflict or high risk, and the increased likelihood of developing mutually acceptable solutions.

Spatiotemporal variation of watershed health propensity through reliability-resilience-vulnerability based drought index (case study: Shazand Watershed in Iran).

Science.gov (United States)

Sadeghi, Seyed Hamidreza; Hazbavi, Zeinab

2017-06-01

Quantitative response of the watershed health to climate variability is of critical importance for watershed managers. However, existing studies seldom considered the impact of climate variability on watershed health. The present study therefore aimed to analyze the temporal and spatial variability of reliability (R el ), resilience (R es ) and vulnerability (V ul ) indicators in node years of 1986, 1998, 2008 and 2014 in connection with Standardized Precipitation Index (SPI) for 24 sub-watersheds in the Shazand Watershed of Markazi Province in Iran. The analysis was based on rainfall variability as one of the main climatic drivers. To achieve the study purposes, the monthly rainfall time series of eight rain gauge stations distributed across the watershed or neighboring areas were analyzed and corresponding SPIs and R el R es V ul indicators were calculated. Ultimately, the spatial variation of SPI oriented R el R es V ul was mapped for the study watershed using Geographic Information System (GIS). The average and standard deviation of SPI-R el R es V ul index for the study years of 1986, 1998, 2008 and 2014 was obtained 0.240±0.025, 0.290±0.036, 0.077±0.0280 and 0.241±0.081, respectively. In overall, the results of the study proved the spatiotemporal variations of SPI-R el R es V ul watershed health index in the study area. Accordingly, all the sub-watersheds of the Shazand Watershed were grouped in unhealthy and very unhealthy conditions in all the study years. For 1986 and 1998 all the sub-watersheds were assessed in unhealthy status. Whilst, it declined to very unhealthy condition in 2008 and then some 75% of the watershed ultimately referred again to unhealthy and the rest still remained under very unhealthy conditions in 2014. Copyright © 2017 Elsevier B.V. All rights reserved.

The Pennsylvania Phosphorus Index and TopoSWAT: A comparison of transport components and approaches

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The regional Chesapeake Bay Conservation Innovation Grant Initiative includes comparison of TopoSWAT results and Phosphorus Index (P Index) evaluations of eight study watersheds throughout the Chesapeake Bay watershed. While similarities exist between the P Index and TopoSWAT, further comparison of ...

Climate change and watershed mercury export in a Coastal Plain watershed

Science.gov (United States)

Heather Golden; Christopher D. Knightes; Paul A. Conrads; Toby D. Feaster; Gary M. Davis; Stephen T. Benedict; Paul M. Bradley

2016-01-01

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.

Flux of nitrogen, phosphorus, and suspended sediment from the Susquehanna River Basin to the Chesapeake Bay during Tropical Storm Lee, September 2011, as an indicator of the effects of reservoir sedimentation on water quality

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Hirsch, Robert M.

2012-01-01

Concentrations of nitrogen, phosphorus, and suspended sediment are measured at the U.S. Geological Survey streamgage at Conowingo Dam at the downstream end of the Susquehanna River Basin in Maryland, where the river flows into the Chesapeake Bay. During the period September 7-15, 2011, in the aftermath of Tropical Storm Lee, concentrations of these three constituents were among the highest ever measured at this site. These measurements indicate that sediment-storage processes behind the three dams on the lower Susquehanna River are evolving. In particular, they indicate that scouring of sediment (and the nitrogen and phosphorus attached to that sediment) may be increasing with time. Trends in flow-normalized fluxes at the Susquehanna River at Conowingo, Maryland, streamgage during 1996-2011 indicate a 3.2-percent decrease in total nitrogen, but a 55-percent increase in total phosphorus and a 97-percent increase in suspended sediment. These large increases in the flux of phosphorus and sediment from the Susquehanna River to the Chesapeake Bay have occurred despite reductions in the fluxes of these constituents from the Susquehanna River watershed upstream from the reservoirs. Although the Tropical Storm Lee flood event contributed about 1.8 percent of the total streamflow from the Susquehanna River to the Chesapeake Bay over the past decade (water years 2002-11), it contributed about 5 percent of the nitrogen, 22 percent of the phosphorus, and 39 percent of the suspended sediment during the same period. These results highlight the importance of brief high-flow events in releasing nitrogen, phosphorus, and sediment derived from the Susquehanna River watershed and stored in the Conowingo Reservoir to the Chesapeake Bay.

Watershed Adaptation Measures to Climate Change Impacts: A case of Kiha Watershed in Albertine Graben

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Zizinga, A.

2017-12-01

Watershed Adaptation Measures to Climate Change Impacts: A case of Kiha Watershed in Albertine GrabenAlex Zizinga1, Moses Tenywa2, Majaliwa Jackson Gilbert1, 1Makerere University, Department of Environmental Sciences, O Box 7062, Kampala, Uganda 1Makerere University, Department of Agricultural Production, P.O Box 7062, Kampala, Uganda Corresponding author: azizinga@caes.mak.ac.ug AbstractThe most pressing issues local communities in Uganda are facing result from land-use and land cover changes exacerbated by climate change impacts. A key issue is the documentation of land-cover changes visible with the ongoing clearance of remaining forests, bush-lands and wetlands for expanding farmland for sugarcane production, producing charcoal and collecting firewood for local distilleries using imported molasses. Decision-makers, resource managers, farmers and practitioners must build their capacity for adaptive measures. Here we present the potential impacts of climate change on watershed hydrological processes in the River Kiha Watershed, located in Western Uganda, Lake Albert Water Management Zone, by using social learning techniques incorporating water users, local stakeholders and researchers. The research team examined different farming and economic activities within the watershed to assess their impacts on catchment water resources, namely on water quality and discharge of river Kiha. We present the impacts of locally induced climate change, which are already manifested in increasing seasonal variability of rainfall. The study aims at answering questions posed by local communities and stakeholders about climate change and its effects on livelihood and key resources, specifically water and soils within the Kiha watershed. Key words: Climate change impacts, Social Learning and Watershed Management

Social Exclusion in Watershed Development: Evidence From the Indo-German Watershed Development Project in Maharashtra

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Eshwer Kale

2011-09-01

Full Text Available The concept of social exclusion is context-specific and there is no uniform paradigm of exclusion across the world. This paper attempts to analyse exclusion of resource-poor groups in watershed development programmes in the Indian context. It aims to explore excluded community groups from the perspective of people’s equal opportunity and equal access to newly generated economic benefits in watershed development programmes. The paper also traces the determinant factors responsible for denial and exclusion of resource-poor groups and describes the detailed processes involved in their exclusion from institutional and livelihood opportunities in watershed programmes. At the same time, the paper also explores suggestions and views of resource-poor groups about their meaningful social inclusion in watershed programme. The Gadiwat Indo-German Watershed Development Project in Aurangabad district in the State of Maharashtra is studied in detail in terms of its social, economic and political realities through mix-method and multi-stakeholder approaches. The key findings of the paper are that landownership, caste, gender, membership in village institutions and/or watershed institutions or close relationship with members, as well as the limitations of the programme guidelines, are the major determinants of institutional inclusion and the extent of resulting economic benefits. The exclusion of resource-poor groups mainly takes the form of their exclusion from institutional representation. In order to promote meaningful social inclusion of resource-poor groups, there is need for a more livelihood-oriented focus and their equal representation and participation in watershed institutions.

Historical occurrence of coho salmon (Oncorhynchus kisutch) in streams of the Santa Cruz Mountain region of California: response to an Endangered Species Act petition to delist coho salmon south of San Francisco Bay

Science.gov (United States)

Brian C. Spence; Walter G. Duffy; John Carlos Garza; Bret Harvey; Susan M. Sogard; Laurie A. Weitkamp; Thomas H. Williams; David A. Boughton

2011-01-01

In November 2003, the National Marine Fisheries Service received a petition from Homer T. McCrary to redefine the southern extent of the Central California Coast Coho Salmon Evolutionarily Significant Unit (CCC Coho Salmon ESU) to exclude populations that spawn in coastal watersheds south of the entrance to San Francisco Bay (i.e., the Golden Gate). The petitioner’s...

Watershed Management: Lessons from Common Property Theory

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John Kerr

2007-10-01

Full Text Available Watershed development is an important component of rural development and natural resource management strategies in many countries. A watershed is a special kind of common pool resource: an area defined by hydrological linkages where optimal management requires coordinated use of natural resources by all users. Management is difficult because natural resources comprising the watershed system have multiple, conflicting uses, so any given management approach will spread benefits and costs unevenly among users. To address these challenges, watershed approaches have evolved from more technocratic to a greater focus on social organization and participation. However, the latter cannot necessarily be widely replicated. In addition, participatory approaches have worked better at a small scale, but hydrological relationships cover a larger scale and some projects have faced tradeoffs in choosing between the two. Optimal approaches for future efforts are not clear, and theories from common property research do not support the idea that complex watershed management can succeed everywhere. Solutions may include simplifying watershed projects, pursuing watershed projects where conditions are favorable, and making other investments elsewhere, including building the organizational capacity that can facilitate watershed management.

Use of a risk-based hydrogeologic model to set remedial goals in a Puget Sound basin watershed

International Nuclear Information System (INIS)

Pascoe, G.; Gould, L.; Martin, J.; Riley, M.; Floyd, T.

1995-01-01

The Port of Seattle is redeveloping industrial land for a container terminal along the southwest Seattle waterfront. Concrete, asphalt, ballast, and a landfill geomembrane will cover the site and prevent direct contact with surface soils, so remedial goals focused on groundwater contamination from subsurface soils. Groundwater at the site flows along an old stormwater drain, in a filled estuary of a small creek, to Elliott Bay. Remedial goals for a variety of organic chemicals, metals, and TPH in subsurface soils were identified to protect marine receptors in the bay and their consumers. Washington State and federal marine water quality criteria were the starting points in the risk-based model, and corresponding concentrations of chemicals in groundwater were back-calculated through a hydrogeologic model. The hydrogeologic model included a mixing zone component in the bay and dilution/attenuation factors along the groundwater transport pathway that were determined from onsite groundwater and surface water chemical concentrations. A rearranged Summers equation was then applied in a second back-calculation to determine subsurface soil concentrations corresponding to the back calculated groundwater concentrations. The equation was based on calculated aquifer flow rates for the small creek watershed and rates of infiltration through surface materials calculated for each redevelopment soil cover type by the HELP model. Results of the risk-based hydrogeologic back-calculation model indicate that, depending on soil cover type at the site, concentrations in subsurface soils of PCBs from 2 to 1,000 mg/kg and of TPH up to free phase concentration would not result in risks to marine organisms or their consumers in Elliott Bay

Water and Poverty in Two Colombian Watersheds

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Nancy Johnson

2009-02-01

Full Text Available Watersheds, especially in the developing world, are increasingly being managed for both environmental conservation and poverty alleviation. How complementary are these objectives? In the context of a watershed, the actual and potential linkages between land and water management and poverty are complex and likely to be very site specific and scale dependent. This study analyses the importance of watershed resources in the livelihoods of the poor in two watersheds in the Colombian Andes. Results of the participatory poverty assessment reveal significant decreases in poverty in both watersheds over the past 25 years, which was largely achieved by the diversification of livelihoods outside of agriculture. Water is an important resource for household welfare. However, opportunities for reducing poverty by increasing the quantity or quality of water available to the poor may be limited. While improved watershed management may have limited direct benefits in terms of poverty alleviation, there are important indirect linkages between watershed management and poverty, mainly through labour and service markets. The results suggest that at the level of the watershed the interests of the rich and the poor are not always in conflict over water. Sectoral as well as socio-economic differences define stakeholder groups in watershed management. The findings have implications for policymakers, planners and practitioners in various sectors involved in the implementation of integrated water resources management (IWRM.

Reproductive health of yellow perch Perca flavescens in selected tributaries of the Chesapeake Bay

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Blazer, Vicki; Pinkney, Alfred E.; Jenkins, Jill A.; Iwanowicz, Luke R.; Minkkinen, Steven; Draugelis-Dale, Rassa O.; Uphoff, James H.

2013-01-01

Reduced recruitment of yellow perch has been noted for a number of years in certain urbanized watersheds (South and Severn Rivers) of the Chesapeake Bay. Other rapidly developing watersheds such as Mattawoman Creek are more recently showing evidence of reduced recruitment of anadromous fishes. In this study, we used a battery of biomarkers to better document the reproductive health of adult yellow perch collected during spring spawning in 2007–2009. Perch were collected in the South and Severn Rivers, Mattawoman Creek and the less developed Choptank and Allen's Fresh watersheds for comparison. Gonadosomatic indices, plasma reproductive hormone concentrations, plasma vitellogenin concentrations and gonad histology were evaluated in mature perch of both sexes. In addition, sperm quantity (cell counts) and quality (total and progressive motility, spermatogenic stage and DNA integrity), were measured in male perch. Many of these biomarkers varied annually and spatially, with some interesting statistical results and trends. Male perch from the Choptank and Allen's Fresh had generally higher sperm counts. In 2008 counts were significantly lower in the perch from the Severn when compared to other sites. The major microscopic gonadal abnormality in males was the proliferation of putative Leydig cells, observed in testes from Severn and less commonly, Mattawoman Creek perch. Observations that could significantly impact egg viability were an apparent lack of final maturation, abnormal yolk and thin, irregular zona pellucida. These were observed primarily in ovaries from Severn, South and less commonly Mattawoman Creek perch. The potential association of these observations with urbanization, impervious surface and chemical contaminants is discussed.

Reproductive health of yellow perch Perca flavescens in selected tributaries of the Chesapeake Bay.

Science.gov (United States)

Blazer, Vicki S; Pinkney, Alfred E; Jenkins, Jill A; Iwanowicz, Luke R; Minkkinen, Steven; Draugelis-Dale, Rassa O; Uphoff, James H

2013-03-01

Reduced recruitment of yellow perch has been noted for a number of years in certain urbanized watersheds (South and Severn Rivers) of the Chesapeake Bay. Other rapidly developing watersheds such as Mattawoman Creek are more recently showing evidence of reduced recruitment of anadromous fishes. In this study, we used a battery of biomarkers to better document the reproductive health of adult yellow perch collected during spring spawning in 2007-2009. Perch were collected in the South and Severn Rivers, Mattawoman Creek and the less developed Choptank and Allen's Fresh watersheds for comparison. Gonadosomatic indices, plasma reproductive hormone concentrations, plasma vitellogenin concentrations and gonad histology were evaluated in mature perch of both sexes. In addition, sperm quantity (cell counts) and quality (total and progressive motility, spermatogenic stage and DNA integrity), were measured in male perch. Many of these biomarkers varied annually and spatially, with some interesting statistical results and trends. Male perch from the Choptank and Allen's Fresh had generally higher sperm counts. In 2008 counts were significantly lower in the perch from the Severn when compared to other sites. The major microscopic gonadal abnormality in males was the proliferation of putative Leydig cells, observed in testes from Severn and less commonly, Mattawoman Creek perch. Observations that could significantly impact egg viability were an apparent lack of final maturation, abnormal yolk and thin, irregular zona pellucida. These were observed primarily in ovaries from Severn, South and less commonly Mattawoman Creek perch. The potential association of these observations with urbanization, impervious surface and chemical contaminants is discussed. Published by Elsevier B.V.

Jordan Lake Watershed Protection District

Data.gov (United States)

Town of Chapel Hill, North Carolina — Polygon representing the area of the Jordan Lake Watershed Protection District. The Watershed Protection District (PDF) is a sensitive area of land that drains to...

33 CFR 162.125 - Sturgeon Bay and the Sturgeon Bay Ship Canal, Wisc.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Sturgeon Bay and the Sturgeon Bay Ship Canal, Wisc. 162.125 Section 162.125 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY INLAND WATERWAYS NAVIGATION REGULATIONS § 162.125 Sturgeon Bay and the Sturgeon Bay Ship...

Identification of spatiotemporal nutrient patterns in a coastal bay via an integrated k-means clustering and gravity model.

Science.gov (United States)

Chang, Ni-Bin; Wimberly, Brent; Xuan, Zhemin

2012-03-01

This study presents an integrated k-means clustering and gravity model (IKCGM) for investigating the spatiotemporal patterns of nutrient and associated dissolved oxygen levels in Tampa Bay, Florida. By using a k-means clustering analysis to first partition the nutrient data into a user-specified number of subsets, it is possible to discover the spatiotemporal patterns of nutrient distribution in the bay and capture the inherent linkages of hydrodynamic and biogeochemical features. Such patterns may then be combined with a gravity model to link the nutrient source contribution from each coastal watershed to the generated clusters in the bay to aid in the source proportion analysis for environmental management. The clustering analysis was carried out based on 1 year (2008) water quality data composed of 55 sample stations throughout Tampa Bay collected by the Environmental Protection Commission of Hillsborough County. In addition, hydrological and river water quality data of the same year were acquired from the United States Geological Survey's National Water Information System to support the gravity modeling analysis. The results show that the k-means model with 8 clusters is the optimal choice, in which cluster 2 at Lower Tampa Bay had the minimum values of total nitrogen (TN) concentrations, chlorophyll a (Chl-a) concentrations, and ocean color values in every season as well as the minimum concentration of total phosphorus (TP) in three consecutive seasons in 2008. The datasets indicate that Lower Tampa Bay is an area with limited nutrient input throughout the year. Cluster 5, located in Middle Tampa Bay, displayed elevated TN concentrations, ocean color values, and Chl-a concentrations, suggesting that high values of colored dissolved organic matter are linked with some nutrient sources. The data presented by the gravity modeling analysis indicate that the Alafia River Basin is the major contributor of nutrients in terms of both TP and TN values in all seasons

Bird surveys at McKinley Bay and Hutchison Bay, Northwest Territories, in 1991

Energy Technology Data Exchange (ETDEWEB)

Cornish, B J; Dickson, D L; Dickson, H L

1992-03-01

McKinley Bay is a shallow protected bay along the eastern Beaufort Sea coast which provides an important habitat for diving ducks. Since 1979, the bay has been the site of a winter harbor and support base for oil and gas exploraton in the Beaufort Sea. Aerial surveys for bird abundance and distribution were conducted in August 1991 as a continuation of long-term monitoring of birds in McKinley Bay and Hutchison Bay, a nearby area used as a control. The main objectives of the 1991 surveys were to expand the set of baseline data on natural annual fluctuations in diving duck numbers, and to determine if numbers of diving ducks had changed since the initial 1981-85 surveys. On the day with the best survey conditions, the population of diving ducks at McKinley bay was estimated at ca 32,000, significantly more than 1981-85. At Hutchison Bay, there were an estimated 11,000 ducks. As in previous years, large numbers of diving ducks were observed off Atkinson Point at the northwest corner of McKinley Bay, at the south end of the bay, and in the northeast corner near a long spit. Most divers in Hutchison Bay were at the west side. Diving ducks, primarily Oldsquaw and scoter, were the most abundant bird group in the study area. Observed distribution patterns of birds are discussed with reference to habitat preferences. 16 refs., 7 figs., 30 tabs.

Pb’s high sedimentation inside the bay mouth of Jiaozhou Bay

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Yang, Dongfang; Miao, Zhenqing; Huang, Xinmin; Wei, Linzhen; Feng, Ming

2017-12-01

Sedimentation is one of the key environmental behaviors of pollutants in the ocean. This paper analyzed the seasonal and temporal variations of Pb’s sedimentation process in Jiaozhou Bay in 1987. Results showed that Pb contents in bottom waters in Jiaozhou Bay in May, July and November 1987 were 1.87-2.60 μg L-1, 15.11-19.68 μg L-1 and 11.08-15.18 μg L-1, and the pollution levels of Pb in May, July and November 1987 were slight, heavy and heavy, respectively. In May 1987, there was low sedimentation process in waters in the outside of the bay mouth, yet were high sedimentation process in waters in the middle and inside of the bay mouth. In July and November 1987, there was low sedimentation process in waters in the outside of the bay mouth, yet were high sedimentation process in waters in the inside of the bay mouth. The seasonal-temporal variation of sedimentation processes of Pb were determined by the variations of sources input and the vertical water’s effect.

Nitrogen fate and Transport in Diverse Agricultural Watersheds

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Essaid, H.; McCarthy, K. A.; Baker, N. T.

2010-12-01

Nitrogen mass budgets have been estimated for ten agricultural watersheds located in a range of hydrologic settings in order to understand the factors controlling the fate of nitrogen applied at the surface. The watersheds, study areas of the Agricultural Chemical Sources, Transport and Fate study of the U.S. Geological Survey National Water Quality Assessment Program, are located in Indiana (IN), Iowa (IA), Maryland (MD), Nebraska (NE), Mississippi (MS) and Washington (WA). They range in size from 7 to 1254 km2, with four of the watersheds nested within larger watersheds. Surface water outflow (normalized to watershed area) ranged from 4 to 83 cm/yr. Crops planted include corn, soybean, small grains, rice, cotton, orchards and vegetables. “Surplus nitrogen” was determined for each watershed by subtracting estimates of crop uptake and volatilization from estimates of nitrogen input from atmospheric deposition, plant fixation, and fertilizer and manure applications for the period from 1987 to 2004. This surplus nitrogen is transported though the watershed via surface and subsurface flow paths, while simultaneously undergoing transformations (such as denitrification and in-stream processing) that result in less export of nitrogen from the watershed. Surface-water discharge and concentration data were used to estimate the export of nitrogen from the watersheds (groundwater outflow from the watersheds was minimal). Subtracting nitrogen export from surplus nitrogen provides an estimate of the net amount of nitrogen removal occurring during internal watershed transport. Watershed average nitrogen surplus ranged from 6 to 49 kg-N/ha. The more permeable and/or greater water flux watersheds (MD, NE, and WA) tended to have larger surplus nitrogen, possibly due to less crop uptake caused by greater leaching and runoff of nitrogen. Almost all of the surplus nitrogen in the low permeability (MS) and tile drained watersheds (IA, IN) was exported from the watershed with

Comparative analyses of hydrological responses of two adjacent watersheds to climate variability and change using the SWAT model

Science.gov (United States)

Lee, Sangchul; Yeo, In-Young; Sadeghi, Ali M.; McCarty, Gregory W.; Hively, Wells; Lang, Megan W.; Sharifi, Amir

2018-01-01

Water quality problems in the Chesapeake Bay Watershed (CBW) are expected to be exacerbated by climate variability and change. However, climate impacts on agricultural lands and resultant nutrient loads into surface water resources are largely unknown. This study evaluated the impacts of climate variability and change on two adjacent watersheds in the Coastal Plain of the CBW, using the Soil and Water Assessment Tool (SWAT) model. We prepared six climate sensitivity scenarios to assess the individual impacts of variations in CO2concentration (590 and 850 ppm), precipitation increase (11 and 21 %), and temperature increase (2.9 and 5.0 °C), based on regional general circulation model (GCM) projections. Further, we considered the ensemble of five GCM projections (2085–2098) under the Representative Concentration Pathway (RCP) 8.5 scenario to evaluate simultaneous changes in CO2, precipitation, and temperature. Using SWAT model simulations from 2001 to 2014 as a baseline scenario, predicted hydrologic outputs (water and nitrate budgets) and crop growth were analyzed. Compared to the baseline scenario, a precipitation increase of 21 % and elevated CO2 concentration of 850 ppm significantly increased streamflow and nitrate loads by 50 and 52 %, respectively, while a temperature increase of 5.0 °C reduced streamflow and nitrate loads by 12 and 13 %, respectively. Crop biomass increased with elevated CO2 concentrations due to enhanced radiation- and water-use efficiency, while it decreased with precipitation and temperature increases. Over the GCM ensemble mean, annual streamflow and nitrate loads showed an increase of  ∼  70 % relative to the baseline scenario, due to elevated CO2 concentrations and precipitation increase. Different hydrological responses to climate change were observed from the two watersheds, due to contrasting land use and soil characteristics. The watershed with a larger percent of croplands demonstrated a greater

Comparative analyses of hydrological responses of two adjacent watersheds to climate variability and change using the SWAT model

Science.gov (United States)

Lee, Sangchul; Yeo, In-Young; Sadeghi, Ali M.; McCarty, Gregory W.; Hively, Wells D.; Lang, Megan W.; Sharifi, Amir

2018-01-01

Water quality problems in the Chesapeake Bay Watershed (CBW) are expected to be exacerbated by climate variability and change. However, climate impacts on agricultural lands and resultant nutrient loads into surface water resources are largely unknown. This study evaluated the impacts of climate variability and change on two adjacent watersheds in the Coastal Plain of the CBW, using the Soil and Water Assessment Tool (SWAT) model. We prepared six climate sensitivity scenarios to assess the individual impacts of variations in CO2 concentration (590 and 850 ppm), precipitation increase (11 and 21 %), and temperature increase (2.9 and 5.0 °C), based on regional general circulation model (GCM) projections. Further, we considered the ensemble of five GCM projections (2085-2098) under the Representative Concentration Pathway (RCP) 8.5 scenario to evaluate simultaneous changes in CO2, precipitation, and temperature. Using SWAT model simulations from 2001 to 2014 as a baseline scenario, predicted hydrologic outputs (water and nitrate budgets) and crop growth were analyzed. Compared to the baseline scenario, a precipitation increase of 21 % and elevated CO2 concentration of 850 ppm significantly increased streamflow and nitrate loads by 50 and 52 %, respectively, while a temperature increase of 5.0 °C reduced streamflow and nitrate loads by 12 and 13 %, respectively. Crop biomass increased with elevated CO2 concentrations due to enhanced radiation- and water-use efficiency, while it decreased with precipitation and temperature increases. Over the GCM ensemble mean, annual streamflow and nitrate loads showed an increase of ˜ 70 % relative to the baseline scenario, due to elevated CO2 concentrations and precipitation increase. Different hydrological responses to climate change were observed from the two watersheds, due to contrasting land use and soil characteristics. The watershed with a larger percent of croplands demonstrated a greater increased rate of 5.2 kg N ha-1 in

Model My Watershed - A Robust Online App to Enable Citizen Scientists to Model Watershed Hydrology and Water Quality at Regulatory-Level Standards

Science.gov (United States)

Daniels, M.; Kerlin, S.; Arscott, D.

2017-12-01

Citizen-based watershed monitoring has historically lacked scientific rigor and geographic scope due to limitation in access to watershed-level data and the high level skills and resources required to adequately model watershed dynamics. Public access to watershed information is currently routed through a variety of governmental data portals and often requires advanced geospatial skills to collect and present in useable forms. At the same time, tremendous financial resources are being invested in watershed restoration and management efforts, and often these resources pass through local stakeholder groups such as conservation NGO, watershed interest groups, and local municipalities without extensive hydrologic knowledge or access to sophisticated modeling resources. Even governmental agencies struggle to understand how to best steer or prioritize restoration investments. A new app, Model My Watershed, was built to improve access to watershed data and modeling capabilities in a fast, accessible, free web-app format. Working across the contiguous United States, the Model My Watershed app provides land cover, soils, aerial imagery and relief, watershed delineation, and stream network delineation. Users can model watersheds or areas of interest and create management scenarios to evaluate implementation of land cover changes and best management practice implementation with both hydrologic and water quality outputs that meet TMDL regulatory standards.

Integrating local research watersheds into hydrologic education: Lessons from the Dry Creek Experimental Watershed

Science.gov (United States)

McNamara, J. P.; Aishlin, P. S.; Flores, A. N.; Benner, S. G.; Marshall, H. P.; Pierce, J. L.

2014-12-01

While a proliferation of instrumented research watersheds and new data sharing technologies has transformed hydrologic research in recent decades, similar advances have not been realized in hydrologic education. Long-standing problems in hydrologic education include discontinuity of hydrologic topics from introductory to advanced courses, inconsistency of content across academic departments, and difficulties in development of laboratory and homework assignments utilizing large time series and spatial data sets. Hydrologic problems are typically not amenable to "back-of-the-chapter" examples. Local, long-term research watersheds offer solutions to these problems. Here, we describe our integration of research and monitoring programs in the Dry Creek Experimental Watershed into undergraduate and graduate hydrology programs at Boise State University. We developed a suite of watershed-based exercises into courses and curriculums using real, tangible datasets from the watershed to teach concepts not amenable to traditional textbook and lecture methods. The aggregation of exercises throughout a course or degree allows for scaffolding of concepts with progressive exposure of advanced concepts throughout a course or degree. The need for exercises of this type is growing as traditional lecture-based classes (passive learning from a local authoritative source) are being replaced with active learning courses that integrate many sources of information through situational factors.

Asotin Creek Model Watershed Plan

Energy Technology Data Exchange (ETDEWEB)

Browne, D.; Holzmiller, J.; Koch, F.; Polumsky, S.; Schlee, D.; Thiessen, G.; Johnson, C.

1995-04-01

The Asotin Creek Model Watershed Plan is the first to be developed in Washington State which is specifically concerned with habitat protection and restoration for salmon and trout. The plan is consistent with the habitat element of the ``Strategy for Salmon``. Asotin Creek is similar in many ways to other salmon-bearing streams in the Snake River system. Its watershed has been significantly impacted by human activities and catastrophic natural events, such as floods and droughts. It supports only remnant salmon and trout populations compared to earlier years. It will require protection and restoration of its fish habitat and riparian corridor in order to increase its salmonid productivity. The watershed coordinator for the Asotin County Conservation District led a locally based process that combined local concerns and knowledge with technology from several agencies to produce the Asotin Creek Model Watershed Plan.

The threat from sea and land. Regional report 2: the Bay of Bengal.

Science.gov (United States)

1994-01-01

This article reports on the environmental threat caused by the Bay of Bengal on the economic situation in Bangladesh and India. More than four-fifths of Bangladesh amount to an extended delta at the confluence of one of the largest river systems in the world, comprising the Ganges, Brahmaputra, and Meghna. In the Brahmaputra watershed, the rate of deforestation caused soil erosion in the Himalayas is five times as much as in the geological past. This sediment loading is often considered to be a prime factor in downstream flooding. Because of this, Bangladesh agriculture products were damaged, which led to economic instability. Furthermore, as a result of the combined impacts of population growth, poverty, no land, and inadequate food supplies, many migrated into the neighboring Indian areas. Moreover, the susceptibility of the Bay of Bengal to cyclones has caused a great number of deaths leaving millions of people homeless. Cyclone episodes are expected to be more frequent as global warming continues. Furthermore, Bangladesh was estimated to be only 5 meters above sea level, which is considered vulnerable to sea level rise. On top of these problems, trouble from the other side of Bangladesh was also predicted with the combined outflow of the Ganges, Brahmaputra, and Meghna leading to more national damage.

Alaska Index of Watershed Integrity

Science.gov (United States)

The US Environmental Protection Agency’s (EPA) Index of Watershed Integrity (IWI) is used to calculate and visualize the status of natural watershed infrastructure that supports ecological processes (e.g., nutrient cycling) and services provided to society (e.g., subsistenc...

Watershed condition [Chapter 4

Science.gov (United States)

Daniel G. Neary; Jonathan W. Long; Malchus B. Baker

2012-01-01

Managers of the Prescott National Forest are obliged to evaluate the conditions of watersheds under their jurisdiction in order to guide informed decisions concerning grazing allotments, forest and woodland management, restoration treatments, and other management initiatives. Watershed condition has been delineated by contrasts between “good” and “poor” conditions (...

Ecosystem responses to long-term nutrient management in an urban estuary: Tampa Bay, Florida, USA

Science.gov (United States)

Greening, H.; Janicki, A.; Sherwood, E. T.; Pribble, R.; Johansson, J. O. R.

2014-12-01

In subtropical Tampa Bay, Florida, USA, we evaluated restoration trajectories before and after nutrient management strategies were implemented using long-term trends in nutrient loading, water quality, primary production, and seagrass extent. Following citizen demands for action, reduction in wastewater nutrient loading of approximately 90% in the late 1970s lowered external total nitrogen (TN) loading by more than 50% within three years. Continuing nutrient management actions from public and private sectors were associated with a steadily declining TN load rate and with concomitant reduction in chlorophyll-a concentrations and ambient nutrient concentrations since the mid-1980s, despite an increase of more than 1 M people living within the Tampa Bay metropolitan area. Water quality (chlorophyll-a concentration, water clarity as indicated by Secchi disk depth, total nitrogen concentration and dissolved oxygen) and seagrass coverage are approaching conditions observed in the 1950s, before the large increases in human population in the watershed. Following recovery from an extreme weather event in 1997-1998, water clarity increased significantly and seagrass is expanding at a rate significantly different than before the event, suggesting a feedback mechanism as observed in other systems. Key elements supporting the nutrient management strategy and concomitant ecosystem recovery in Tampa Bay include: 1) active community involvement, including agreement about quantifiable restoration goals; 2) regulatory and voluntary reduction in nutrient loadings from point, atmospheric, and nonpoint sources; 3) long-term water quality and seagrass extent monitoring; and 4) a commitment from public and private sectors to work together to attain restoration goals. A shift from a turbid, phytoplankton-based system to a clear water, seagrass-based system that began in the 1980s following comprehensive nutrient loading reductions has resulted in a present-day Tampa Bay which looks and

The onset of deglaciation of Cumberland Bay and Stromness Bay, South Georgia

NARCIS (Netherlands)

Van Der Putten, N.; Verbruggen, C.

Carbon dating of basal peat deposits in Cumberland Bay and Stromness Bay and sediments from a lake in Stromness Bay, South Georgia indicates deglaciation at the very beginning of the Holocene before c. 9500 14C yr BP. This post-dates the deglaciation of one local lake which has been ice-free since

Watershed Education for Broadcast Meteorologists

Science.gov (United States)

Lamos, J. P.; Sliter, D.; Espinoza, S.; Spangler, T. C.

2006-12-01

The National Environmental Education and Training Organization (NEETF) published a report in 2005 that summarized the findings of ten years of NEETF and Roper Research. The report stated, "Our years of data from Roper surveys show a persistent pattern of environmental ignorance even among the most educated and influential members of society." Market research has also shown that 80% of television viewers list the weather as the primary reason for watching the local news. Broadcast meteorologists, with a broader understanding of environmental and related sciences have an opportunity to use their weathercasts to inform the public about the environment and the factors that influence environmental health. As "station scientists," broadcast meteorologists can use the weather, and people's connection to it, to broaden their understanding of the environment they live in. Weather and watershed conditions associated with flooding and drought have major human and environmental impacts. Increasing the awareness of the general public about basic aspects of the hydrologic landscape can be an important part of mitigating the adverse effects of too much or too little precipitation, and of protecting the environment as well. The concept of a watershed as a person's natural neighborhood is a very important one for understanding hydrologic and environmental issues. Everyone lives in a watershed, and the health of a watershed is the result of the interplay between weather and human activity. This paper describes an online course to give broadcast meteorologists a basic understanding of watersheds and how watersheds are impacted by weather. It discusses how to convey watershed science to a media- savvy audience as well as how to model the communication of watershed and hydrologic concepts to the public. The course uses a narrative, story-like style to present its content. It is organized into six short units of instruction, each approximately 20 minutes in duration. Each unit is

Evapotranspiration sensitivity to air temperature across a snow-influenced watershed: Space-for-time substitution versus integrated watershed modeling

Science.gov (United States)

Jepsen, S. M.; Harmon, T. C.; Ficklin, D. L.; Molotch, N. P.; Guan, B.

2018-01-01

Changes in long-term, montane actual evapotranspiration (ET) in response to climate change could impact future water supplies and forest species composition. For scenarios of atmospheric warming, predicted changes in long-term ET tend to differ between studies using space-for-time substitution (STS) models and integrated watershed models, and the influence of spatially varying factors on these differences is unclear. To examine this, we compared warming-induced (+2 to +6 °C) changes in ET simulated by an STS model and an integrated watershed model across zones of elevation, substrate available water capacity, and slope in the snow-influenced upper San Joaquin River watershed, Sierra Nevada, USA. We used the Soil Water and Assessment Tool (SWAT) for the watershed modeling and a Budyko-type relationship for the STS modeling. Spatially averaged increases in ET from the STS model increasingly surpassed those from the SWAT model in the higher elevation zones of the watershed, resulting in 2.3-2.6 times greater values from the STS model at the watershed scale. In sparse, deep colluvium or glacial soils on gentle slopes, the SWAT model produced ET increases exceeding those from the STS model. However, watershed areas associated with these conditions were too localized for SWAT to produce spatially averaged ET-gains comparable to the STS model. The SWAT model results nevertheless demonstrate that such soils on high-elevation, gentle slopes will form ET "hot spots" exhibiting disproportionately large increases in ET, and concomitant reductions in runoff yield, in response to warming. Predicted ET responses to warming from STS models and integrated watershed models may, in general, substantially differ (e.g., factor of 2-3) for snow-influenced watersheds exhibiting an elevational gradient in substrate water holding capacity and slope. Long-term water supplies in these settings may therefore be more resilient to warming than STS model predictions would suggest.

Water quality trading opportunities in two sub-watersheds in the northern Lake Okeechobee watershed.

Science.gov (United States)

Corrales, Juliana; Naja, G Melodie; Bhat, Mahadev G; Miralles-Wilhelm, Fernando

2017-07-01

For decades, the increase of nutrient enrichment has threatened the ecological integrity and economic sustainability of many rivers, lakes, and coastal waters, including Lake Okeechobee, the second largest freshwater lake in the contiguous United States. Water quality trading programs have been an area of active development to both, reduce nutrient pollution and minimize abatement costs. The objective of this study was to apply a comprehensive modeling framework, integrating a hydrologic-water quality model with an economic model, to assess and compare the cost-effectiveness of a water quality trading program over a command-and-control approach in order to reduce phosphorus loadings to Lake Okeechobee. The Upper Kissimmee (UK) and Taylor Creek/Nubbin Slough (TCNS) sub-watersheds, identified as major sources of total phosphorus (TP) loadings to the lake, were selected for this analysis. The effect of different caps on the market potential was assessed while considering four factors: the least-cost abatement solutions, credit prices, potential cost savings, and credit supply and demand. Hypothetical trading scenarios were also developed, using the optimal caps selected for the two sub-watersheds. In both sub-watersheds, a phosphorus credit trading program was less expensive than the conventional command-and-control approach. While attaining cost-effectiveness, keeping optimal credit prices, and fostering market competition, phosphorus reduction targets of 46% and 32% were selected as the most appropriate caps in the UK and TCNS sub-watersheds, respectively. Wastewater treatment facilities and urban areas in the UK, and concentrated animal feeding operations in the TCNS sub-watershed were identified as potential credit buyers, whereas improved pastures were identified as the major credit sellers in both sub-watersheds. The estimated net cost savings resulting from implementing a phosphorus trading program in the UK and TCNS sub-watersheds were 76% ($ 34.9 million per

Watersheds in disordered media

Directory of Open Access Journals (Sweden)

José S. Andrade Jr.

2015-02-01

Full Text Available What is the best way to divide a rugged landscape? Since ancient times, watershedsseparating adjacent water systems that flow, for example, toward different seas, have beenused to delimit boundaries. Interestingly, serious and even tense border disputes betweencountries have relied on the subtle geometrical properties of these tortuous lines. For instance,slight and even anthropogenic modifications of landscapes can produce large changes in awatershed, and the effects can be highly nonlocal. Although the watershed concept arisesnaturally in geomorphology, where it plays a fundamental role in water management, landslide,and flood prevention, it also has important applications in seemingly unrelated fields suchas image processing and medicine. Despite the far-reaching consequences of the scalingproperties on watershed-related hydrological and political issues, it was only recently that a moreprofound and revealing connection has been disclosed between the concept of watershed andstatistical physics of disordered systems. This review initially surveys the origin and definition of awatershed line in a geomorphological framework to subsequently introduce its basic geometricaland physical properties. Results on statistical properties of watersheds obtained from artificialmodel landscapes generated with long-range correlations are presented and shown to be ingood qualitative and quantitative agreement with real landscapes.

Long-term impacts due to sediment supply changes towards the San Francisco Bay-Delta system

Science.gov (United States)

Achete, F.; Van der Wegen, M. V.; Jaffe, B. E.

2012-12-01

The Sacramento-San Joaquin Delta and Watershed is the main source of fresh water and sediment to San Francisco Bay. Mid 19th century hydraulic mining in the catchment caused an excessive supply of sediment. After mining activities stopped, in the first part of the 20th century several hydraulic structures were built deviating fresh water and trapping sediment upstream. The main purpose of most of these structures is water storage for irrigation and/or water supply Wright and Schoellhamer (2004) show that from 1957 to 2001 the sediment load carried to San Francisco Bay has decreased by about one half. The lack of sediments may lead to a different erosion/deposition pattern in the Bay-Delta system causing problems like mud flat erosion, shift in navigation channel, land subsidence and changing habitat for endemic species. The objective of this work is to identify and quantify morphological shifts in the Bay-Delta system due to variation in fresh water and sediment supply. In this study, we couple the Delta and Bay in a unique model network (the Delta-Bay model). This coupling allows tracking of sediment from Sacramento via the Delta and Bay and through the Golden Gate, making it possible to identify erosion and deposition areas. The numerical model applied is an unstructured, process-based model (D-Flow Flexible Mesh developed by Deltares). It simulates the hydrodynamics and morphodynamics of the area on a detailed, 64000-node mesh (10-200m mesh length scale) on a timescale of minutes. The morphological impact is assessed for multiple scenarios with different input of sediment and fresh water. A statistical analysis is performed to account for uncertainty of model parameters and climate change impacts. The fresh water discharge already has a strong natural seasonal and inter-annual variation. The human impact by foreseen different water pumping strategies due to the peripheral canal will be considered. Jaffe et al. (2007) has shown that substantial morphological

Payments for watershed services: opportunities and realities

Energy Technology Data Exchange (ETDEWEB)

Bond, Ivan

2007-08-15

Many nations have found that regulatory approaches to land and water management have limited impact. An alternative is to create incentives for sound management - under mechanisms known as payments for ecosystem services. It is a simple idea: people who look after ecosystems that benefit others should be recognised and rewarded. In the case of watersheds, downstream beneficiaries of wise upstream land and water use should compensate the stewards. To be effective these 'payments for watershed services' must cover the cost of watershed management. In developing countries, they might also aid local development and reduce poverty. But new research shows that the problems in watersheds are complex and not easily solved. Payments for watershed services do not guarantee poverty reduction and cannot replace the best aspects of regulation.

Watershed Scale Impacts of Stormwater Green Infrastructure ...

Science.gov (United States)

Despite the increasing use of urban stormwater green infrastructure (SGI), including detention ponds and rain gardens, few studies have quantified the cumulative effects of multiple SGI projects on hydrology and water quality at the watershed scale. To assess the effects of SGI, Baltimore County, MD, Montgomery County, MD, and Washington, DC, were selected based on the availability of data on SGI, water quality, and stream flow. The watershed scale impact of SGI was evaluated by assessing how increased spatial density of SGI correlates with stream hydrology and nitrogen exports over space and time. The most common SGI types were detention ponds (58%), followed by marshes (12%), sand filters (9%), wet ponds (7%), infiltration trenches (4%), and rain gardens (2%). When controlling for watersheds size and percent impervious surface cover, watersheds with greater amounts of SGI (>10% SGI) have 44% lower peak runoff, 26% less frequent runoff events, and 26% less variable runoff than watersheds with lower SGI. Watersheds with more SGI also show 44% less NO3− and 48% less total nitrogen exports compared to watersheds with minimal SGI. There was no significant reduction in combined sewer overflows in watersheds with greater SGI. Based on specific SGI types, infiltration trenches (R2 = 0.35) showed the strongest correlation with hydrologic metrics, likely due to their ability to attenuate flow, while bioretention (R2 = 0.19) and wet ponds (R2 = 0.12) showed stronger

Application of the ReNuMa model in the Sha He river watershed: tools for watershed environmental management.

Science.gov (United States)

Sha, Jian; Liu, Min; Wang, Dong; Swaney, Dennis P; Wang, Yuqiu

2013-07-30

Models and related analytical methods are critical tools for use in modern watershed management. A modeling approach for quantifying the source apportionment of dissolved nitrogen (DN) and associated tools for examining the sensitivity and uncertainty of the model estimates were assessed for the Sha He River (SHR) watershed in China. The Regional Nutrient Management model (ReNuMa) was used to infer the primary sources of DN in the SHR watershed. This model is based on the Generalized Watershed Loading Functions (GWLF) and the Net Anthropogenic Nutrient Input (NANI) framework, modified to improve the characterization of subsurface hydrology and septic system loads. Hydrochemical processes of the SHR watershed, including streamflow, DN load fluxes, and corresponding DN concentration responses, were simulated following calibrations against observations of streamflow and DN fluxes. Uncertainty analyses were conducted with a Monte Carlo analysis to vary model parameters for assessing the associated variations in model outputs. The model performed accurately at the watershed scale and provided estimates of monthly streamflows and nutrient loads as well as DN source apportionments. The simulations identified the dominant contribution of agricultural land use and significant monthly variations. These results provide valuable support for science-based watershed management decisions and indicate the utility of ReNuMa for such applications. Copyright © 2013 Elsevier Ltd. All rights reserved.

GoMRC Website ‘Meta-analysis Report: Land-use and submerged aquatic vegetation change in the Gulf of Mexico’

Energy Technology Data Exchange (ETDEWEB)

Judd, Chaeli; Stefansson, Emily S.; Brushnahan, Heather

2007-12-06

Over the past century, health and spatial extent of seagrasses has decreased dramatically in the Gulf of Mexico. While some of the changes can be explained by direct impacts to the seagrass beds, we hypothesize that changes in the land use in the watersheds can also be correlated with the decline of seagrasses. Through this meta-analysis, we researched historical and compared trends in seagrass populations and land use in five bays and their watersheds within the Gulf of Mexico: Mobile Bay, Perdido Bay, Tampa Bay, Charlotte Harbor, and Galveston Bay. Using both historical records and spatial datasets, we examined land use and seagrass trends in these five areas.

A History of Vegetation, Sediment and Nutrient Dynamics at Tivoli North Bay, Hudson Estuary, New York

Science.gov (United States)

Sritrairat, Sanpisa; Peteet, Dorothy M.; Kenna, Timothy C.; Sambrotto, Ray; Kurdyla, Dorothy; Guilderson, Tom

2012-01-01

We conduct a stratigraphic paleoecological investigation at a Hudson River National Estuarine Research Reserve (HRNERR) site, Tivoli Bays, spanning the past 1100 years. Marsh sediment cores were analyzed for ecosystem changes using multiple proxies, including pollen, spores, macrofossils, charcoal, sediment bulk chemistry, and stable carbon and nitrogen isotopes. The results reveal climatic shifts such as the warm and dry Medieval Warm Period (MWP) followed by the cooler Little Ice Age (LIA), along with significant anthropogenic influence on the watershed ecosystem. A five-fold expansion of invasive species, including Typha angustifolia and Phragmites australis, is documented along with marked changes in sediment composition and nutrient input. During the last century, a ten-fold sedimentation rate increase due to land-use changes is observed. The large magnitude of shifts in vegetation, sedimentation, and nutrients during the last few centuries suggest that human activities have made the greatest impact to the marshes of the Hudson Estuary during the last millennium. Climate variability and ecosystem changes similar to those observed at other marshes in northeastern and mid-Atlantic estuaries, attest to the widespread regional signature recorded at Tivoli Bays.

Elevation - LiDAR Survey Minnehaha Creek, MN Watershed

Data.gov (United States)

Army Corps of Engineers, Department of the Army, Department of Defense — LiDAR Bare-Earth Grid - Minnehaha Creek Watershed District. The Minnehaha Creek watershed is located primarily in Hennepin County, Minnesota. The watershed covers...

75 FR 8297 - Tongass National Forest, Thorne Bay Ranger District, Thorne Bay, AK

Science.gov (United States)

2010-02-24

..., Thorne Bay, AK AGENCY: Forest Service, USDA. ACTION: Cancellation of Notice of intent to prepare an... Roberts, Zone Planner, Thorne Bay Ranger District, Tongass National Forest, P.O. Box 19001, Thorne Bay, AK 99919, telephone: 907-828-3250. SUPPLEMENTARY INFORMATION: The 47,007-acre Kosciusko Project Area is...

77 FR 44140 - Drawbridge Operation Regulation; Sturgeon Bay Ship Canal, Sturgeon Bay, WI

Science.gov (United States)

2012-07-27

... Maple-Oregon Bridges so vehicular traffic congestion would not develop on downtown Sturgeon Bay streets... movement of vehicular traffic in Sturgeon Bay. The Sturgeon Bay Ship Canal is approximately 8.6 miles long... significant increase in vehicular and vessel traffic during the peak tourist and navigation season between...

Using Four Capitals to Assess Watershed Sustainability

Science.gov (United States)

Pérez-Maqueo, Octavio; Martinez, M. Luisa; Vázquez, Gabriela; Equihua, Miguel

2013-03-01

The La Antigua watershed drains into the Gulf of Mexico and can be considered as one of the most important areas in Mexico because of its high productivity, history, and biodiversity, although poverty remains high in the area in spite of these positive attributes. In this study, we performed an integrated assessment of the watershed to recommend a better direction toward a sustainable management in which the four capitals (natural, human, social, and built) are balanced. We contrasted these four capitals in the municipalities of the upper, middle and lower watershed and found that natural capital (natural ecosystems and ecosystem services) was higher in the upper and middle watershed, while human and social capitals (literacy, health, education and income) were generally higher downstream. Overall, Human Development Index was negatively correlated with the percentage of natural ecosystems in the watershed, especially in the upper and lower watershed regions. Our results indicate that natural capital must be fully considered in projections for increasing human development, so that natural resources can be preserved and managed adequately while sustaining intergenerational well-being.

Modelling of the estimated contributions of different sub-watersheds and sources to phosphorous export and loading from the Dongting Lake watershed, China.

Science.gov (United States)

Hou, Ying; Chen, Weiping; Liao, Yuehua; Luo, Yueping

2017-11-03

Considerable growth in the economy and population of the Dongting Lake watershed in Southern China has increased phosphorus loading to the lake and resulted in a growing risk of lake eutrophication. This study aimed to reveal the spatial pattern and sources of phosphorus export and loading from the watershed. We applied an export coefficient model and the Dillon-Rigler model to quantify contributions of different sub-watersheds and sources to the total phosphorus (TP) export and loading in 2010. Together, the upper and lower reaches of the Xiang River watershed and the Dongting Lake Area contributed 60.9% of the TP exported from the entire watershed. Livestock husbandry appeared to be the largest anthropogenic source of TP, contributing more than 50% of the TP exported from each secondary sub-watersheds. The actual TP loading to the lake in 2010 was 62.9% more than the permissible annual TP loading for compliance with the Class III water quality standard for lakes. Three primary sub-watersheds-the Dongting Lake Area, the Xiang River, and the Yuan River watersheds-contributed 91.2% of the total TP loading. As the largest contributor among all sources, livestock husbandry contributed nearly 50% of the TP loading from the Dongting Lake Area and more than 60% from each of the other primary sub-watersheds. This study provides a methodology to identify the key sources and locations of TP export and loading in large lake watersheds. The study can provide a reference for the decision-making for controlling P pollution in the Dongting Lake watershed.

Assessing the cumulative impacts of geographically isolated wetlands on watershed hydrology using the SWAT model coupled with improved wetland modules.

Science.gov (United States)

Lee, S; Yeo, I-Y; Lang, M W; Sadeghi, A M; McCarty, G W; Moglen, G E; Evenson, G R

2018-06-07

Despite recognizing the importance of wetlands in the Coastal Plain of the Chesapeake Bay Watershed (CBW) in terms of ecosystem services, our understanding of wetland functions has mostly been limited to individual wetlands and overall catchment-scale wetland functions have rarely been investigated. This study is aimed at assessing the cumulative impacts of wetlands on watershed hydrology for an agricultural watershed within the Coastal Plain of the CBW using the Soil and Water Assessment Tool (SWAT). We employed two improved wetland modules for enhanced representation of physical processes and spatial distribution of riparian wetlands (RWs) and geographically isolated wetlands (GIWs). This study focused on GIWs as their hydrological impacts on watershed hydrology are poorly understood and GIWs are poorly protected. Multiple wetland scenarios were prepared by removing all or portions of the baseline GIW condition indicated by the U.S. Fish and Wildlife Service National Wetlands Inventory geospatial dataset. We further compared the impacts of GIWs and RWs on downstream flow (i.e., streamflow at the watershed outlet). Our simulation results showed that GIWs strongly influenced downstream flow by altering water transport mechanisms in upstream areas. Loss of all GIWs reduced both water routed to GIWs and water infiltrated into the soil through the bottom of GIWs, leading to an increase in surface runoff of 9% and a decrease in groundwater flow of 7% in upstream areas. These changes resulted in increased variability of downstream flow in response to extreme flow conditions. GIW loss also induced an increase in month to month variability of downstream flow and a decrease in the baseflow contribution to streamflow. Loss of all GIWs was shown to cause a greater fluctuation of downstream flow than loss of all RWs for this study site, due to a greater total water storage capacity of GIWs. Our findings indicate that GIWs play a significant role in controlling hydrological

Physical processes in a coupled bay-estuary coastal system: Whitsand Bay and Plymouth Sound

Science.gov (United States)

Uncles, R. J.; Stephens, J. A.; Harris, C.

2015-09-01

Whitsand Bay and Plymouth Sound are located in the southwest of England. The Bay and Sound are separated by the ∼2-3 km-wide Rame Peninsula and connected by ∼10-20 m-deep English Channel waters. Results are presented from measurements of waves and currents, drogue tracking, surveys of salinity, temperature and turbidity during stratified and unstratified conditions, and bed sediment surveys. 2D and 3D hydrodynamic models are used to explore the generation of tidally- and wind-driven residual currents, flow separation and the formation of the Rame eddy, and the coupling between the Bay and the Sound. Tidal currents flow around the Rame Peninsula from the Sound to the Bay between approximately 3 h before to 2 h after low water and form a transport path between them that conveys lower salinity, higher turbidity waters from the Sound to the Bay. These waters are then transported into the Bay as part of the Bay-mouth limb of the Rame eddy and subsequently conveyed to the near-shore, east-going limb and re-circulated back towards Rame Head. The Simpson-Hunter stratification parameter indicates that much of the Sound and Bay are likely to stratify thermally during summer months. Temperature stratification in both is pronounced during summer and is largely determined by coastal, deeper-water stratification offshore. Small tidal stresses in the Bay are unable to move bed sediment of the observed sizes. However, the Bay and Sound are subjected to large waves that are capable of driving a substantial bed-load sediment transport. Measurements show relatively low levels of turbidity, but these respond rapidly to, and have a strong correlation with, wave height.

Estimation of the peak factor based on watershed characteristics

Energy Technology Data Exchange (ETDEWEB)

Gauthier, Jean; Nolin, Simon; Ruest, Benoit [BPR Inc., Quebec, (Canada)

2010-07-01

Hydraulic modeling and dam structure design require the river flood flow as a primary input. For a given flood event, the ratio of peak flow over mean daily flow defines the peak factor. The peak factor value is dependent on the watershed and location along the river. The main goal of this study consisted in finding a relationship between watershed characteristics and this peak factor. Regression analyses were carried out on 53 natural watersheds located in the southern part of the province of Quebec using data from the Centre d'expertise hydrique du Quebec (CEHQ). The watershed characteristics included in the analyses were the watershed area, the maximum flow length, the mean slope, the lake proportion and the mean elevation. The results showed that watershed area and length are the major parameters influencing the peak factor. Nine natural watersheds were also used to test the use of a multivariable model in order to determine the peak factor for ungauged watersheds.

Economic Tools for Managing Nitrogen in Coastal Watersheds ...

Science.gov (United States)

Watershed managers are interested in using economics to communicate the value of estuarine resources to the wider community, determine the most cost-effective means to reduce nitrogen pollution, and evaluate the benefits of taking action to improve coastal ecosystems. We spoke to coastal watershed managers who had commissioned economic studies and found that they were largely satisfied with the information and their ability to communicate the importance of coastal ecosystems. However, while managers were able to use these studies as communication tools, methods used in some studies were inconsistent with what some economists consider best practices. In addition, many watershed managers are grappling with how to implement nitrogen management activities in a way that is both cost-effective and achieves environmental goals, while maintaining public support. These and other issues led to this project. Our intent is to provide information to watershed managers and others interested in watershed management – such as National Estuary Programs, local governments, or nongovernmental organizations – on economic tools for managing nitrogen in coastal watersheds, and to economists and other analysts who are interested in assisting them in meeting their needs. Watershed management requires balancing scientific, political, and social issues to solve environmental problems. This document summarizes questions that watershed managers have about using economic analysis, and g

Modeling soil erosion in a watershed

OpenAIRE

Lanuza, R.

1999-01-01

Most erosion models have been developed based on a plot scale and have limited application to a watershed due to the differences in aerial scale. In order to address this limitation, a GIS-assisted methodology for modeling soil erosion was developed using PCRaster to predict the rate of soil erosion at watershed level; identify the location of erosion prone areas; and analyze the impact of landuse changes on soil erosion. The general methodology of desktop modeling or soil erosion at watershe...

NYC Reservoirs Watershed Areas (HUC 12)

Data.gov (United States)

U.S. Environmental Protection Agency — This NYC Reservoirs Watershed Areas (HUC 12) GIS layer was derived from the 12-Digit National Watershed Boundary Database (WBD) at 1:24,000 for EPA Region 2 and...

78 FR 46813 - Safety Zone; Evening on the Bay Fireworks; Sturgeon Bay, WI

Science.gov (United States)

2013-08-02

...-AA00 Safety Zone; Evening on the Bay Fireworks; Sturgeon Bay, WI AGENCY: Coast Guard, DHS. ACTION.... This temporary safety zone will restrict vessels from a portion of Sturgeon Bay due to a fireworks... hazards associated with the fireworks display. DATES: This rule is effective from 8 p.m. until 10 p.m. on...

77 FR 38488 - Safety Zone; Alexandria Bay Chamber of Commerce, St. Lawrence River, Alexandria Bay, NY

Science.gov (United States)

2012-06-28

... 1625-AA00 Safety Zone; Alexandria Bay Chamber of Commerce, St. Lawrence River, Alexandria Bay, NY... restrict vessels from a portion of the St. Lawrence River during the Alexandria Bay Chamber of Commerce... of proposed rulemaking (NPRM) entitled Safety Zone; Alexandria Bay Chamber of Commerce, St. Lawrence...

Ground-water discharge and base-flow nitrate loads of nontidal streams, and their relation to a hydrogeomorphic classification of the Chesapeake Bay Watershed, middle Atlantic Coast

Science.gov (United States)

Bachman, L. Joseph; Lindsey, Bruce D.; Brakebill, John W.; Powars, David S.

1998-01-01

Existing data on base-flow and groundwater nitrate loads were compiled and analyzed to assess the significance of groundwater discharge as a source of the nitrate load to nontidal streams of the Chesapeake Bay watershed. These estimates were then related to hydrogeomorphic settings based on lithology and physiographic province to provide insight on the areal distribution of ground-water discharge. Base-flow nitrate load accounted for 26 to about 100 percent of total-flow nitrate load, with a median value of 56 percent, and it accounted for 17 to 80 percent of total-flow total-nitrogen load, with a median value of 48 percent. Hydrograph separations were conducted on continuous streamflow records from 276 gaging stations within the watershed. The values for base flow thus calculated were considered an estimate of ground-water discharge. The ratio of base flow to total flow provided an estimate of the relative importance of ground-water discharge within a basin. Base-flow nitrate loads, total-flow nitrate loads, and total-flow total-nitrogen loads were previously computed from water-quality and discharge measurements by use of a regression model. Base-flow nitrate loads were available from 78 stations, total-flow nitrate loads were available from 86 stations, and total-flow total-nitrogen loads were available for 48 stations. The percentage of base-flow nitrate load to total-flow nitrate load could be computed for 57 stations, whereas the percentage of base-flow nitrate load to totalflow total-nitrogen load could be computed for 36 stations. These loads were divided by the basin area to obtain yields, which were used to compare the nitrate discharge from basins of different sizes. The results indicate that ground-water discharge is a significant source of water and nitrate to the total streamflow and nitrate load. Base flow accounted for 16 to 92 percent of total streamflow at the 276 sampling sites, with a median value of 54 percent. It is estimated that of the 50

WATERSHED BASED WEB GIS: CASE STUDY OF PALOPO WATERSHED AREA SOUTH SULAWESI, INDONESIA

Directory of Open Access Journals (Sweden)

Jalaluddin Rumi PRASAD

2017-09-01

Full Text Available Data and land resource information complete, accurate, and current is an input in management planning, evaluation, and monitoring Watershed. Implementation of this research is conducted with optimum utilization of secondary data that is supported by direct field measurement data, digitalizing the maps associated, Geographic Information Systems modeling, and model calibration. This research has resulted in a Geographic Information System Management of potential Watershed GIS Web-based or abbreviated WEB GIS MPPDAS using Palopo watershed area, South Sulawesi as a case study sites for the development of a prototype that consists of three applications the main website ie Web Portal, Web GIS, and Web Tutorial. The system is built to show online (and offline maps watershed in the administrative area of Palopo along with the location of its potential accumulated in the four (4 groups of layers, including groups of main layer (2 layer, a group of base layer (14 layers, groups of thematic layers (12 layers, a group of policy layer (8 layer. In addition to display a map, use the WEB application of GIS MPPDAS can also use tools or controls in the application to perform analyzes in its monitoring and evaluation, including: Geocoding, Add layer, Digitizing, Selection, Measurements, Graph, Filtering, Geolocation, Overlay cartographic, and etc.

Watershed modeling applications in south Texas

Science.gov (United States)

Pedraza, Diana E.; Ockerman, Darwin J.

2012-01-01

Watershed models can be used to simulate natural and human-altered processes including the flow of water and associated transport of sediment, chemicals, nutrients, and microbial organisms within a watershed. Simulation of these processes is useful for addressing a wide range of water-resource challenges, such as quantifying changes in water availability over time, understanding the effects of development and land-use changes on water resources, quantifying changes in constituent loads and yields over time, and quantifying aquifer recharge temporally and spatially throughout a watershed.

Watershed District

Data.gov (United States)

Kansas Data Access and Support Center — Boundaries show on this map are derived from legal descriptions contained in petitions to the Kansas Secretary of State for the creation or extension of watershed...

Application of a virtual watershed in academic education

OpenAIRE

Horn , A. L.; Hörmann , G.; Fohrer , N.

2005-01-01

International audience; Hydrologic models of watersheds often represent complex systems which are difficult to understand regarding to their structure and dynamics. Virtual watersheds, i.e. watersheds which exist only in the virtual reality of a computer system, are an approach to simplify access to this real-world complexity. In this study we present the virtual watershed KIELSHED-1, a 117 km2 v-shaped valley with grassland on a "Cambisol" soil type. Two weather scenarios are delivered with ...

A strong CO2 sink enhanced by eutrophication in a tropical coastal embayment (Guanabara Bay, Rio de Janeiro, Brazil)

Science.gov (United States)

Cotovicz, L. C., Jr.; Knoppers, B. A.; Brandini, N.; Costa Santos, S. J.; Abril, G.

2015-10-01

In contrast to its small surface area, the coastal zone plays a disproportionate role in the global carbon cycle. Carbon production, transformation, emission and burial rates at the land-ocean interface are significant at the global scale but still poorly known, especially in tropical regions. Surface water pCO2 and ancillary parameters were monitored during nine field campaigns between April 2013 and April 2014 in Guanabara Bay, a tropical eutrophic to hypertrophic semi-enclosed estuarine embayment surrounded by the city of Rio de Janeiro, southeast Brazil. Water pCO2 varied between 22 and 3715 ppmv in the bay, showing spatial, diurnal and seasonal trends that mirrored those of dissolved oxygen (DO) and chlorophyll a (Chl a). Marked pCO2 undersaturation was prevalent in the shallow, confined and thermally stratified waters of the upper bay, whereas pCO2 oversaturation was restricted to sites close to the small river mouths and small sewage channels, which covered only 10 % of the bay's area. Substantial daily variations in pCO2 (up to 395 ppmv between dawn and dusk) were also registered and could be integrated temporally and spatially for the establishment of net diurnal, seasonal and annual CO2 fluxes. In contrast to other estuaries worldwide, Guanabara Bay behaved as a net sink of atmospheric CO2, a property enhanced by the concomitant effects of strong radiation intensity, thermal stratification, and high availability of nutrients, which promotes phytoplankton development and net autotrophy. The calculated CO2 fluxes for Guanabara Bay ranged between -9.6 and -18.3 mol C m-2 yr-1, of the same order of magnitude as the organic carbon burial and organic carbon inputs from the watershed. The positive and high net community production (52.1 mol C m-2 yr-1) confirms the high carbon production in the bay. This autotrophic metabolism is apparently enhanced by eutrophication. Our results show that global CO2 budgetary assertions still lack information on tropical

Global perspective of watershed management

Science.gov (United States)

Kenneth N. Brooks; Karlyn Eckman

2000-01-01

This paper discusses the role of watershed management in moving towards sustainable natural resource and agricultural development. Examples from 30 field projects and six training projects involving over 25 countries are presented to illustrate watershed management initiatives that have been implemented over the last half of the 20th century. The level of success has...

Assessment of landscape change and occurrence at watershed ...

African Journals Online (AJOL)

... the southern watershed zones. Monitoring land cover change at the watershed scale is more indicative of impact level and where efforts for managing and conserving the urban landscape should be prioritized. Key words: Urban expansion, land cover type, remote sensing, watershed units, urban landscape conservation.

Application of a virtual watershed in academic education

Directory of Open Access Journals (Sweden)

A. L. Horn

2005-01-01

Full Text Available Hydrologic models of watersheds often represent complex systems which are difficult to understand regarding to their structure and dynamics. Virtual watersheds, i.e. watersheds which exist only in the virtual reality of a computer system, are an approach to simplify access to this real-world complexity. In this study we present the virtual watershed KIELSHED-1, a 117 km2 v-shaped valley with grassland on a "Cambisol" soil type. Two weather scenarios are delivered with the watershed: a simplified artificial weather scenario based on long-term data of a German weather station as well as an unmodified data record. The input data and parameters are compiled according to the conventions of the SWAT 2000 hydrological model. KIELSHED-1 is mainly used for education, and illustrative application examples, i.e. calculation of water balance, model calibration, development of land use scenarios, give an insight to the capabilities of the virtual watershed.

Understanding toxicity at the watershed scale : design of the Syncrude Sandhill Fen watershed research project

International Nuclear Information System (INIS)

Wytrykush, C.

2010-01-01

Fens are peat-accumulating wetlands with a water table consisting of mineral-rich ground or surface water. This study discussed the construction of a fen-type reclaimed wetland constructed in a post-mining oil sands landscape. Syncrude Canada's Sandhill fen watershed project represents the first attempt at constructing a fen wetland in the oil sands region. The wetland and its watershed will be constructed on a soft tailings deposit. The design basis for the fen and watershed was developed by a team of researchers and scientists. The aim of the fen design was to control the salinity caused by tailings consolidation and seepage over time. Methods of mitigating potentially toxic effects from salinity were discussed.

Regionalization of SWAT Model Parameters for Use in Ungauged Watersheds

Directory of Open Access Journals (Sweden)

Indrajeet Chaubey

2010-11-01

Full Text Available There has been a steady shift towards modeling and model-based approaches as primary methods of assessing watershed response to hydrologic inputs and land management, and of quantifying watershed-wide best management practice (BMP effectiveness. Watershed models often require some degree of calibration and validation to achieve adequate watershed and therefore BMP representation. This is, however, only possible for gauged watersheds. There are many watersheds for which there are very little or no monitoring data available, thus the question as to whether it would be possible to extend and/or generalize model parameters obtained through calibration of gauged watersheds to ungauged watersheds within the same region. This study explored the possibility of developing regionalized model parameter sets for use in ungauged watersheds. The study evaluated two regionalization methods: global averaging, and regression-based parameters, on the SWAT model using data from priority watersheds in Arkansas. Resulting parameters were tested and model performance determined on three gauged watersheds. Nash-Sutcliffe efficiencies (NS for stream flow obtained using regression-based parameters (0.53–0.83 compared well with corresponding values obtained through model calibration (0.45–0.90. Model performance obtained using global averaged parameter values was also generally acceptable (0.4 ≤ NS ≤ 0.75. Results from this study indicate that regionalized parameter sets for the SWAT model can be obtained and used for making satisfactory hydrologic response predictions in ungauged watersheds.

Integrated Modeling System for Analysis of Watershed Water Balance: A Case Study in the Tims Branch Watershed, South Carolina

Science.gov (United States)

Setegn, S. G.; Mahmoudi, M.; Lawrence, A.; Duque, N.

2015-12-01

The Applied Research Center at Florida International University (ARC-FIU) is supporting the soil and groundwater remediation efforts of the U.S. Department of Energy (DOE) Savannah River Site (SRS) by developing a surface water model to simulate the hydrology and the fate and transport of contaminants and sediment in the Tims Branch watershed. Hydrological models are useful tool in water and land resource development and decision-making for watershed management. Moreover, simulation of hydrological processes improves understanding of the environmental dynamics and helps to manage and protect water resources and the environment. MIKE SHE, an advanced integrated modeling system is used to simulate the hydrological processes of the Tim Branch watershed with the objective of developing an integrated modeling system to improve understanding of the physical, chemical and biological processes within the Tims Branch watershed. MIKE SHE simulates water flow in the entire land based phase of the hydrological cycle from rainfall to river flow, via various flow processes such as, overland flow, infiltration, evapotranspiration, and groundwater flow. In this study a MIKE SHE model is developed and applied to the Tim branch watershed to study the watershed response to storm events and understand the water balance of the watershed under different climatic and catchment characteristics. The preliminary result of the integrated model indicated that variation in the depth of overland flow highly depend on the amount and distribution of rainfall in the watershed. The ultimate goal of this project is to couple the MIKE SHE and MIKE 11 models to integrate the hydrological component in the land phase of hydrological cycle and stream flow process. The coupled MIKE SHE/MIKE 11 model will further be integrated with an Ecolab module to represent a range of water quality, contaminant transport, and ecological processes with respect to the stream, surface water and groundwater in the Tims

AUTOMATED GEOSPATIAL WATERSHED ASSESSMENT ...

Science.gov (United States)

The Automated Geospatial Watershed Assessment tool (AGWA) is a GIS interface jointly developed by the USDA Agricultural Research Service, the U.S. Environmental Protection Agency, the University of Arizona, and the University of Wyoming to automate the parameterization and execution of the Soil Water Assessment Tool (SWAT) and KINEmatic Runoff and EROSion (KINEROS2) hydrologic models. The application of these two models allows AGWA to conduct hydrologic modeling and watershed assessments at multiple temporal and spatial scales. AGWA’s current outputs are runoff (volumes and peaks) and sediment yield, plus nitrogen and phosphorus with the SWAT model. AGWA uses commonly available GIS data layers to fully parameterize, execute, and visualize results from both models. Through an intuitive interface the user selects an outlet from which AGWA delineates and discretizes the watershed using a Digital Elevation Model (DEM) based on the individual model requirements. The watershed model elements are then intersected with soils and land cover data layers to derive the requisite model input parameters. The chosen model is then executed, and the results are imported back into AGWA for visualization. This allows managers to identify potential problem areas where additional monitoring can be undertaken or mitigation activities can be focused. AGWA also has tools to apply an array of best management practices. There are currently two versions of AGWA available; AGWA 1.5 for

Evaluation of Soil Erosion and Sediment Yield from Ridge Watersheds Leading to Guánica Bay, Puerto Rico, Using SWAT Model

Science.gov (United States)

Increased sediment loading to reservoirs and, ultimately, to Guánica Bay and reef areas is a significant concern in Puerto Rico. Sediment deposition has significantly reduced storage capacity of reservoirs, and sediment-attached contaminants can stress corals and negative...

Centennial record of anthropogenic impacts in Galveston Bay: Evidence from trace metals (Hg, Pb, Ni, Zn) and lignin oxidation products.

Science.gov (United States)

Al Mukaimi, Mohammad E; Kaiser, Karl; Williams, Joshua R; Dellapenna, Timothy M; Louchouarn, Patrick; Santschi, Peter H

2018-06-01

During the 20th century the impacts of industrialization and urbanization in Galveston Bay resulted in significant shifts in trace metals (Hg, Pb, Ni, Zn) and vascular plant biomarkers (lignin phenols) recorded within the surface sediments and sediment cores profile. A total of 22 sediment cores were collected in Galveston Bay in order to reconstruct the historical input of Hg, Pb, Ni, Zn and terrestrial organic matter. Total Hg (T-Hg) concentration ranged between 6 and 162 ng g -1 in surface sediments, and showed decreasing concentrations southward from the Houston Ship Channel (HSC) toward the open estuary. Core profiles of T-Hg and trace metals (Ni, Zn) showed substantial inputs starting in 1905, with peak concentrations between 1960 and 1970's, and decreasing thereafter with exception to Pb, which peaked around 1930-1940s. Stable carbon isotopes and lignin phenols showed an increasing input of terrestrial organic matter driven by urban development within the watershed in the early 1940s. Both the enrichment factor and the geoaccumulation index (I geo ) for T-Hg as a measure of the effectiveness of environmental management practices showed substantial improvements since the 1970s. The natural recovery rate in Galveston Bay since the peak input of T-Hg was non-linear and displayed a slow recovery during the twenty-first century. Copyright © 2018 Elsevier Ltd. All rights reserved.

Watershed Profiles and Stream-net Structure of Vesuvio Volcano, Italy

Science.gov (United States)

Lin, Z.; Oguchi, T.; Komatsu, G.

2006-12-01

Watershed topography including stream-net structure in 32 watersheds of Vesuvio Volcano was analyzed using a DEM with a 20-m resolution, with special attention to geomorphological differences between the northern ?0-8 area and the other areas. The longitudinal and transverse profiles and stream-nets of the watersheds were extracted from the DEM. Drainage density and statistical morphometric parameters representing the shape of the profiles were investigated, and their relations with other basic morphometric parameters such as slope angle were examined. The relationships between drainage density and slope angle for each watershed can be divided into two types: Type 1 - negative correlation and Type 2 - convex-form correlation. The Type 2 watersheds have smaller bifurcation ratios and larger low-order stream lengths than the Type 1 watersheds, indicating that low-order streams in the Type 2 watersheds are more integrated. The results of longitudinal and transverse profile analyses also show that the topography of the Type 2 watersheds is simpler and more organized than that of the Type 1 watersheds, suggesting that the Type 2 watersheds are closer to equilibrium conditions. The Type 2 watersheds are located in the steepest and highest part of the somma area, where only limited eruption products have been deposited during the Holocene, due to the existence of the high and steep outer rim of the caldera at the top of the volcano. The results including the existence of the two types are similar to those from non-volcanic watersheds in Japan, indicating that stream-net studies combined with profile analysis using DEMs are effective in discussing the erosional stages of watersheds.

Coastal watershed management across an international border in the Tijuana River watershed

Science.gov (United States)

Fernandez, Linda

2005-05-01

The paper develops and applies a game theoretic model of upstream and downstream countries to examine cooperative and noncooperative strategies of a common watershed. The application to the Tijuana River watershed shared by the United States and Mexico provides quantification of the strategies for internalizing water quality externalities to upstream and downstream originating from sedimentation. Results show that different transfer payments, such as the Chander/Tulkens cost sharing rule and the Shapley value, imply the size of the existing transfer from downstream to upstream could increase the amount currently allocated.

McKenzie River Watershed Coordination, Annual Report 2001-2002.

Energy Technology Data Exchange (ETDEWEB)

Thrailkil, Jim

2003-11-01

BPA funding, in conjunction with contributions from numerous partners organizations and grant funds supports the McKenzie Watershed Council's (MWC) efforts to coordinate restoration and monitoring programs of federal, state, local government, and residents within the watershed. Primary goals of the MWC are to improve resource stewardship and conserve fish, wildlife, and water quality resources. Underpinning the goals is the MWC's baseline program centered on relationship building and information sharing. Objectives for FY02 included: (1) Continue to coordinate McKenzie Watershed activities among diverse groups to restore fish and wildlife habitat in the watershed, with a focus on the middle to lower McKenzie, including private lands and the McKenzie-Willamette confluence area; (2) Influence behavior of watershed residents to benefit watershed function though an outreach and education program, utilizing (BPA funded) Assessment and Conservation Strategy information to provide a context for prioritized action; (3) Continue to maintain and sustain a highly functional watershed council; (4) Maintain and improve water quality concerns through the continuation of Council-sponsored monitoring and evaluation programs; and (5) Continue to secure other funding for watershed restoration and protection projects and Council operations.

[Evaluation on the eco-economic benefits of small watershed in Beijing mountainous area: a case of Yanqi River watershed].

Science.gov (United States)

Xiao, Hui-Jie; Wei, Zi-Gang; Wang, Qing; Zhu, Xiao-Bo

2012-12-01

Based on the theory of harmonious development of ecological economy, a total of 13 evaluation indices were selected from the ecological, economic, and social sub-systems of Yanqi River watershed in Huairou District of Beijing. The selected evaluation indices were normalized by using trapezoid functions, and the weights of the evaluation indices were determined by analytic hierarchy process. Then, the eco-economic benefits of the watershed were evaluated with weighted composite index method. From 2004 to 2011, the ecological, economic, and social benefits of Yanqi River watershed all had somewhat increase, among which, ecological benefit increased most, with the value changed from 0.210 in 2004 to 0.255 in 2011 and an increment of 21.5%. The eco-economic benefits of the watershed increased from 0.734 in 2004 to 0.840 in 2011, with an increment of 14.2%. At present, the watershed reached the stage of advanced ecosystem, being in beneficial circulation and harmonious development of ecology, economy, and society.

Gradient Analysis and Classification of Carolina Bay Vegetation: A Framework for Bay Wetlands Conservation and Restoration

Energy Technology Data Exchange (ETDEWEB)

Diane De Steven,Ph.D.; Maureen Tone,PhD.

1997-10-01

This report address four project objectives: (1) Gradient model of Carolina bay vegetation on the SRS--The authors use ordination analyses to identify environmental and landscape factors that are correlated with vegetation composition. Significant factors can provide a framework for site-based conservation of existing diversity, and they may also be useful site predictors for potential vegetation in bay restorations. (2) Regional analysis of Carolina bay vegetation diversity--They expand the ordination analyses to assess the degree to which SRS bays encompass the range of vegetation diversity found in the regional landscape of South Carolina's western Upper Coastal Plain. Such comparisons can indicate floristic status relative to regional potentials and identify missing species or community elements that might be re-introduced or restored. (3) Classification of vegetation communities in Upper Coastal Plain bays--They use cluster analysis to identify plant community-types at the regional scale, and explore how this classification may be functional with respect to significant environmental and landscape factors. An environmentally-based classification at the whole-bay level can provide a system of templates for managing bays as individual units and for restoring bays to desired plant communities. (4) Qualitative model for bay vegetation dynamics--They analyze present-day vegetation in relation to historic land uses and disturbances. The distinctive history of SRS bays provides the possibility of assessing pathways of post-disturbance succession. They attempt to develop a coarse-scale model of vegetation shifts in response to changing site factors; such qualitative models can provide a basis for suggesting management interventions that may be needed to maintain desired vegetation in protected or restored bays.

Grays River Watershed Geomorphic Analysis

Energy Technology Data Exchange (ETDEWEB)

Geist, David R

2005-04-30

This investigation, completed for the Pacific Northwest National Laboratory (PNNL), is part of the Grays River Watershed and Biological Assessment commissioned by Bonneville Power Administration under project number 2003-013-00 to assess impacts on salmon habitat in the upper Grays River watershed and present recommendations for habitat improvement. This report presents the findings of the geomorphic assessment and is intended to support the overall PNNL project by evaluating the following: The effects of historical and current land use practices on erosion and sedimentation within the channel network The ways in which these effects have influenced the sediment budget of the upper watershed The resulting responses in the main stem Grays River upstream of State Highway 4 The past and future implications for salmon habitat.

Potential hazards of environmental contaminants to avifauna residing in the Chesapeake Bay estuary

Science.gov (United States)

Rattner, Barnett A.; McGowan, Peter C.

2007-01-01

A search of the Contaminant Exposure and Effects-Terrestrial Vertebrates (CEE-TV) database revealed that 70% of the 839 Chesapeake Bay records deal with avian species. Studies conducted on waterbirds in the past 15 years indicate that organochlorine contaminants have declined in eggs and tissues, although p,p'-DDE, total polychlorinated biphenyls (PCBs) and coplanar PCB congeners may still exert sublethal and reproductive effects in some locations. There have been numerous reports of avian die-off events related to organophosphorus and carbamate pesticides. More contemporary contaminants (e.g., alkylphenols, ethoxylates, perfluorinated compounds, polybrominated diphenyl ethers) are detectable in bird eggs in the most industrialized portions of the Bay, but interpretation of these data is difficult because adverse effect levels are incompletely known for birds. Two moderaterized oil spills resulted in the death of several hundred birds, and about 500 smaller spill events occur annually in the watershed. With the exception of lead, concentrations of cadmium, mercury, and selenium in eggs and tissues appear to be below toxic thresholds for waterbirds. Fishing tackle and discarded plastics, that can entangle and kill young and adults, are prevalent in nests in some Bay tributaries. It is apparent that exposure and potential effects of several classes of contaminants (e.g., dioxins, dibenzofurans, rodenticides, pharmaceuticals, personal care products, lead shot, and some metals) have not been systematically examined in the past 15 years, highlighting the need for toxicological evaluation of birds found dead, and perhaps an avian ecotoxicological monitoring program. Although oil spills, spent lead shot, some pesticides, and industrial pollutants occasionally harm Chesapeake avifauna, contaminants no longer evoke the population level effects that were observed in Ospreys (Pandion haliaetus) and Bald Eagles (Haliaeetus leucocephalus) through the 1970s.

18 CFR 801.9 - Watershed management.

Science.gov (United States)

2010-04-01

... 18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false Watershed management... GENERAL POLICIES § 801.9 Watershed management. (a) The character, extent, and quality of water resources... management including soil and water conservation measures, land restoration and rehabilitation, erosion...

Watershed Management Optimization Support Tool (WMOST) ...

Science.gov (United States)

EPA's Watershed Management Optimization Support Tool (WMOST) version 2 is a decision support tool designed to facilitate integrated water management by communities at the small watershed scale. WMOST allows users to look across management options in stormwater (including green infrastructure), wastewater, drinking water, and land conservation programs to find the least cost solutions. The pdf version of these presentations accompany the recorded webinar with closed captions to be posted on the WMOST web page. The webinar was recorded at the time a training workshop took place for EPA's Watershed Management Optimization Support Tool (WMOST, v2).

Scale and watershed features determine lake chemistry patterns across physiographic regions in the far north of Ontario, Canada

Directory of Open Access Journals (Sweden)

Josef MacLeod

2016-11-01

Full Text Available Changes in the far north of Ontario (>50°N latitude, like climate warming and increased industrial development, will have direct effects on watershed characteristics and lakes. To better understand the nature of remote northern lakes that span the Canadian Shield and Hudson Bay Lowlands, and to address the pressing need for limnological data for this vast, little-studied area of Ontario, lake chemistry surveys were conducted during 2011-2012. Lakes at the transition between these physiographic regions displayed highly variable water chemistry, reflecting the peatland landscape with a mix of bog and fen watersheds, and variations in the extent of permafrost. In the transition area, Shield and Lowlands lakes could not be clearly differentiated based on water chemistry; peat cover decouples, to varying degrees, the lakes from the influences of bedrock and surficial deposits. Regional chemistry differences were apparent across a much broader area of northern Ontario, due to large-scale spatial changes in geology and in the extent of peatlands and permafrost.  Shield lakes in the far northwest of Ontario had Ca, Mg, and TP concentrations markedly higher than those of many Lowlands lakes and previously studied Shield lakes south of 50°N, related to an abundance of lacustrine and glacial end-moraine deposits in the north.

DNR Watersheds - DNR Level 02 - HUC 04

Data.gov (United States)

Minnesota Department of Natural Resources — These data consists of watershed delineations in one seamless dataset of drainage areas called Minnesota Department of Natural Resources (DNR) Level 02 Watersheds....

Linking Resilience of Aquatic Species to Watershed Condition

Science.gov (United States)

Flitcroft, R. L.

2017-12-01

Watershed condition means different things to different people. From the perspective of aquatic ecology, watershed condition may be interpreted to mean the capacity of a watershed to support life history diversity of native species. Diversity in expression of life history is thought to confer resilience allowing portions of the broader population to survive stressful conditions. Different species have different life history strategies, many of which were developed through adaptation to regional or local environmental conditions and natural disturbance regimes. By reviewing adaptation strategies for species of interest at regional scales, characteristics of watersheds that confer resilience may be determined. Such assessments must be completed at multiple levels of spatial organization (i.e. sub-watershed, watershed, region) allowing assessments to be inferred across broad spatial extents. In a project on the Wenatchee River watershed, we guided models of wildfire effects on bull trout and spring Chinook from a meta-population perspective to determine risks to survival at local and population scales over multiple extents of spatial organization. In other work in the Oregon Coast Range, we found that historic landslides continue to exert habitat-forming pressure at local scales, leading to patchiness in distribution of habitats for different life stages of coho salmon. Further, climate change work in Oregon estuaries identified different vulnerabilities in terms of juvenile rearing habitat depending on the species of interest and the intensity of future changes in climate. All of these studies point to the importance of considering physical conditions in watersheds at multiple spatial extents from the perspective of native aquatic species in order to understand risks to long-term survival. The broader implications of watershed condition, from this perspective, is the determination of physical attributes that confer resilience to native biota. This may require

Understanding Human Impact: Second Graders Explore Watershed Dynamics

Science.gov (United States)

Magruder, Robin; Rosenauer, Julia

2016-01-01

This article describes a second grade science enrichment unit with a focus on human impact, both positive and negative, on the living and nonliving components of the local watershed. Investigating the local watershed gave the unit a personal and pragmatic connection to students' lives because they depend on the local watershed for what they need…

Experimental Watershed Study Designs: A Tool for Advancing Process Understanding and Management of Mixed-Land-Use Watersheds

Science.gov (United States)

Hubbart, J. A.; Kellner, R. E.; Zeiger, S. J.

2016-12-01

Advancements in watershed management are both a major challenge, and urgent need of this century. The experimental watershed study (EWS) approach provides critical baseline and long-term information that can improve decision-making, and reduce misallocation of mitigation investments. Historically, the EWS approach was used in wildland watersheds to quantitatively characterize basic landscape alterations (e.g. forest harvest, road building). However, in recent years, EWS is being repurposed in contemporary multiple-land-use watersheds comprising a mosaic of land use practices such as urbanizing centers, industry, agriculture, and rural development. The EWS method provides scalable and transferrable results that address the uncertainties of development, while providing a scientific basis for total maximum daily load (TMDL) targets in increasing numbers of Clean Water Act 303(d) listed waters. Collaborative adaptive management (CAM) programs, designed to consider the needs of many stakeholders, can also benefit from EWS-generated information, which can be used for best decision making, and serve as a guidance tool throughout the CAM program duration. Of similar importance, long-term EWS monitoring programs create a model system to show stakeholders how investing in rigorous scientific research initiatives improves decision-making, thereby increasing management efficiencies through more focused investments. The evolution from classic wildland EWS designs to contemporary EWS designs in multiple-land-use watersheds will be presented while illustrating how such an approach can encourage innovation, cooperation, and trust among watershed stakeholders working to reach the common goal of improving and sustaining hydrologic regimes and water quality.

Model My Watershed: A high-performance cloud application for public engagement, watershed modeling and conservation decision support

Science.gov (United States)

Aufdenkampe, A. K.; Tarboton, D. G.; Horsburgh, J. S.; Mayorga, E.; McFarland, M.; Robbins, A.; Haag, S.; Shokoufandeh, A.; Evans, B. M.; Arscott, D. B.

2017-12-01

The Model My Watershed Web app (https://app.wikiwatershed.org/) and the BiG-CZ Data Portal (http://portal.bigcz.org/) and are web applications that share a common codebase and a common goal to deliver high-performance discovery, visualization and analysis of geospatial data in an intuitive user interface in web browser. Model My Watershed (MMW) was designed as a decision support system for watershed conservation implementation. BiG CZ Data Portal was designed to provide context and background data for research sites. Users begin by creating an Area of Interest, via an automated watershed delineation tool, a free draw tool, selection of a predefined area such as a county or USGS Hydrological Unit (HUC), or uploading a custom polygon. Both Web apps visualize and provide summary statistics of land use, soil groups, streams, climate and other geospatial information. MMW then allows users to run a watershed model to simulate different scenarios of human impacts on stormwater runoff and water-quality. BiG CZ Data Portal allows users to search for scientific and monitoring data within the Area of Interest, which also serves as a prototype for the upcoming Monitor My Watershed web app. Both systems integrate with CUAHSI cyberinfrastructure, including visualizing observational data from CUAHSI Water Data Center and storing user data via CUAHSI HydroShare. Both systems also integrate with the new EnviroDIY Water Quality Data Portal (http://data.envirodiy.org/), a system for crowd-sourcing environmental monitoring data using open-source sensor stations (http://envirodiy.org/mayfly/) and based on the Observations Data Model v2.

Suburban watershed nitrogen retention: Estimating the effectiveness of stormwater management structures

Science.gov (United States)

Koch, Benjamin J.; Febria, Catherine M.; Cooke, Roger M.; Hosen, Jacob D.; Baker, Matthew E.; Colson, Abigail R.; Filoso, Solange; Hayhoe, Katharine; Loperfido, J. V.; Stoner, Anne M.K.; Palmer, Margaret A.

2015-01-01

Excess nitrogen (N) is a primary driver of freshwater and coastal eutrophication globally, and urban stormwater is a rapidly growing source of N pollution. Stormwater best management practices (BMPs) are used widely to remove excess N from runoff in urban and suburban areas, and are expected to perform under a wide variety of environmental conditions. Yet the capacity of BMPs to retain excess N varies; and both the variation and the drivers thereof are largely unknown, hindering the ability of water resource managers to meet water quality targets in a cost-effective way. Here, we use structured expert judgment (SEJ), a performance-weighted method of expert elicitation, to quantify the uncertainty in BMP performance under a range of site-specific environmental conditions and to estimate the extent to which key environmental factors influence variation in BMP performance. We hypothesized that rain event frequency and magnitude, BMP type and size, and physiographic province would significantly influence the experts’ estimates of N retention by BMPs common to suburban Piedmont and Coastal Plain watersheds of the Chesapeake Bay region.

Impact of climate change and climate anomalies on hydrologic and biogeochemical processes in an agricultural catchment of the Chesapeake Bay watershed, USA.

Science.gov (United States)

Wagena, Moges B; Collick, Amy S; Ross, Andrew C; Najjar, Raymond G; Rau, Benjamin; Sommerlot, Andrew R; Fuka, Daniel R; Kleinman, Peter J A; Easton, Zachary M

2018-05-16

Nutrient export from agricultural landscapes is a water quality concern and the cause of mitigation activities worldwide. Climate change impacts hydrology and nutrient cycling by changing soil moisture, stoichiometric nutrient ratios, and soil temperature, potentially complicating mitigation measures. This research quantifies the impact of climate change and climate anomalies on hydrology, nutrient cycling, and greenhouse gas emissions in an agricultural catchment of the Chesapeake Bay watershed. We force a calibrated model with seven downscaled and bias-corrected regional climate models and derived climate anomalies to assess their impact on hydrology and the export of nitrate (NO 3 -), phosphorus (P), and sediment, and emissions of nitrous oxide (N 2 O) and di-nitrogen (N 2 ). Model-average (±standard deviation) results indicate that climate change, through an increase in precipitation and temperature, will result in substantial increases in winter/spring flow (10.6 ± 12.3%), NO 3 - (17.3 ± 6.4%), dissolved P (32.3 ± 18.4%), total P (24.8 ± 16.9%), and sediment (25.2 ± 16.6%) export, and a slight increases in N 2 O (0.3 ± 4.8%) and N 2 (0.2 ± 11.8%) emissions. Conversely, decreases in summer flow (-29.1 ± 24.6%) and the export of dissolved P (-15.5 ± 26.4%), total P (-16.3 ± 20.7%), sediment (-20.7 ± 18.3%), and NO 3 - (-29.1 ± 27.8%) are driven by greater evapotranspiration from increasing summer temperatures. Decreases in N 2 O (-26.9 ± 15.7%) and N 2 (-36.6 ± 22.9%) are predicted in the summer and driven by drier soils. While the changes in flow are related directly to changes in precipitation and temperature, the changes in nutrient and sediment export are, to some extent, driven by changes in agricultural management that climate change induces, such as earlier spring tillage and altered nutrient application timing and by alterations to nutrient cycling in the soil. Copyright © 2018

Discharge, water-quality characteristics, and nutrient loads from McKay Bay, Delaney Creek, and East Bay, Tampa, Florida, 1991-1993

Science.gov (United States)

Stoker, Y.E.; Levesque, V.A.; Fritz, E.M.

1996-01-01

Nutrient enrichment in Tampa Bay has caused a decline in water quality in the estuary. Efforts to reduce the nutrient loading to Tampa Bay have resulted in improvement in water quality from 1981 to 1991. However, Tampa Bay still is onsidered enriched with nutrients. Water quality in East Bay (located at the northeastern part of Hillsborough Bay, which is an embayment in Tampa Bay) is not improving at the same rate as the rest of the bay. East Bay is the center of shipping activity in Tampa Bay and the seventh largest port in the United States. One of the primary cargoes is phosphate ore and related products such as fertilizer. The potential for nutrient loading to East Bay from shipping activities is high and has not previously been measured. Nitrogen and phosphorus loads from East Bay to Hillsborough Bay were measured during selected time periods during June 1992 through May 1993; these data were used to estimate seasonal and annual loads. These loads were evaluated to determine whether the loss of fertilizer products from shipping activities resulted in increased nutrient loading to Hillsborough Bay. Discharge was measured, and water-quality samples were collected at the head of East Bay (exiting McKay Bay), and at the mouth of East Bay. Discharge and nitrogen and phosphorus concentrations for the period June 1992 through May 1993 were used to compute loads. Discharges from McKay Bay, Delaney Creek, and East Bay are highly variable because of the effect of tide. Flow patterns during discharge measurements generally were unidirectional in McKay Bay and Delaney Creek, but more complex, bidirectional patterns were observed at the mouth of East Bay. Tidally affected discharge data were digitally filtered with the Godin filter to remove the effects of tide so that residual, or net, discharge could be determined. Daily mean discharge from McKay Bay ranged from -1,900 to 2,420 cubic feet per second; from Delaney Creek, -3.8 to 162 cubic feet per second; and from East

46 CFR 7.20 - Nantucket Sound, Vineyard Sound, Buzzards Bay, Narragansett Bay, MA, Block Island Sound and...

Science.gov (United States)

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Nantucket Sound, Vineyard Sound, Buzzards Bay, Narragansett Bay, MA, Block Island Sound and easterly entrance to Long Island Sound, NY. 7.20 Section 7.20... Atlantic Coast § 7.20 Nantucket Sound, Vineyard Sound, Buzzards Bay, Narragansett Bay, MA, Block Island...

Chapter 19. Cumulative watershed effects and watershed analysis

Science.gov (United States)

Leslie M. Reid

1998-01-01

Cumulative watershed effects are environmental changes that are affected by more than.one land-use activity and that are influenced by.processes involving the generation or transport.of water. Almost all environmental changes are.cumulative effects, and almost all land-use.activities contribute to cumulative effects

Iskuulpa Watershed Management Plan : A Five-Year Plan for Protecting and Enhancing Fish and Wildlife Habitats in the Iskuulpa Watershed.

Energy Technology Data Exchange (ETDEWEB)

Confederated Tribes of the Umatilla Indian Reservation Wildlife Program

2003-01-01

The Confederated Tribes of the Umatilla Indian Reservation (CTUIR) propose to protect, enhance, and mitigate wildlife and wildlife habitat and watershed resources in the Iskuulpa Watershed. The Iskuulpa Watershed Project was approved as a Columbia River Basin Wildlife Fish and Mitigation Project by the Bonneville Power Administration (BPA) and Northwest Power Planning Council (NWPPC) in 1998. Iskuulpa will contribute towards meeting BPA's obligation to compensate for wildlife habitat losses resulting from the construction of the John Day and McNary Hydroelectric facilities on the Columbia River. By funding the enhancement and operation and maintenance of the Iskuulpa Watershed, BPA will receive credit towards their mitigation debt. The purpose of the Iskuulpa Watershed management plan update is to provide programmatic and site-specific standards and guidelines on how the Iskuulpa Watershed will be managed over the next three years. This plan provides overall guidance on both short and long term activities that will move the area towards the goals, objectives, and desired future conditions for the planning area. The plan will incorporate managed and protected wildlife and wildlife habitat, including operations and maintenance, enhancements, and access and travel management.

33 CFR 165.1182 - Safety/Security Zone: San Francisco Bay, San Pablo Bay, Carquinez Strait, and Suisun Bay, CA.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Safety/Security Zone: San... Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY... Areas Eleventh Coast Guard District § 165.1182 Safety/Security Zone: San Francisco Bay, San Pablo Bay...

Increased terrestrial to ocean sediment and carbon fluxes in the northern Chesapeake Bay associated with twentieth century land alteration

Science.gov (United States)

Saenger, C.; Cronin, T. M.; Willard, D.; Halka, J.; Kerhin, R.

2008-01-01

We calculated Chesapeake Bay (CB) sediment and carbon fluxes before and after major anthropogenic land clearance using robust monitoring, modeling and sedimentary data. Four distinct fluxes in the estuarine system were considered including (1) the flux of eroded material from the watershed to streams, (2) the flux of suspended sediment at river fall lines, (3) the burial flux in tributary sediments, and (4) the burial flux in main CB sediments. The sedimentary maximum in Ambrosia (ragweed) pollen marked peak land clearance (~1900 a.d.). Rivers feeding CB had a total organic carbon (TOC)/total suspended solids of 0.24??0.12, and we used this observation to calculate TOC fluxes from sediment fluxes. Sediment and carbon fluxes increased by 138-269% across all four regions after land clearance. Our results demonstrate that sediment delivery to CB is subject to significant lags and that excess post-land clearance sediment loads have not reached the ocean. Post-land clearance increases in erosional flux from watersheds, and burial in estuaries are important processes that must be considered to calculate accurate global sediment and carbon budgets. ?? 2008 Coastal and Estuarine Research Federation.

78 FR 62293 - Safety Zone, Oyster Festival 30th Anniversary Fireworks Display, Oyster Bay; Oyster Bay, NY

Science.gov (United States)

2013-10-15

... Safety Zone, Oyster Festival 30th Anniversary Fireworks Display, Oyster Bay; Oyster Bay, NY AGENCY: Coast... zone on the navigable waters of Oyster Bay near Oyster Bay, NY for the Oyster Festival 30th Anniversary... Oyster Festival 30th Anniversary Fireworks Display is scheduled for October 19, 2013 and is one of...

Watershed manipulation project: Field implementation plan for 1990-1992

International Nuclear Information System (INIS)

Erickson, H.; Narahara, A.M.; Rustad, L.E.; Mitchell, M.; Lee, J.

1993-02-01

The Bear Brook Watershed in Maine (BBWM) was established in 1986 at Lead Mountain, Maine as part of the Environmental Protection Agency's (EPA) Watershed Manipulation Project (WPM). The goals of the project are to: (1) assess the chemical response of a small upland forested watershed to increased loadings of SO4, (2) determine interactions among biogeochemical mechanisms controlling watershed response to acidic deposition, and (3) test the assumptions of the Direct/Delayed Response Programs (DDRP) computer models of watershed acidification. The document summarizes the field procedures used in the establishment and initial implementation of the plot- and catchment- scale activities at the BBWM, and outlines plans for 1990-02 project activities

Imbalance of Nature due to Anthropogenic Activities in the Bay of Bacorehuis, Sinaloa, Mexico

Science.gov (United States)

Torrecillas Nunez, C.; Cárdenas Cota, H.

2013-05-01

Pollution is further enhancing water scarcity by reducing water usability downstream, globally the most prevalent water quality problem is eutrophication, a result of high-nutrient loads, which substantially impairs beneficial uses of water. Projected food production needs and increasing wastewater effluents associated with an increasing population over the next three decades suggest a 10%-15% increase in the river input of nitrogen loads into coastal ecosystems (UNO, 2009). Our study in the Bay of Bacorehuis in the State of Sinaloa, which was carried out due to a request from local fishermen who wanted to find out the reason for fishing stocks depletion, confirmed this trend with the consequent imbalance of nature. Sinaloa depends heavily on intensive agricultural production to support its economy which in turn relies on water irrigation and the application of agro-chemicals. The research project included a desk top study of geophysical and environmental factors as well as sampling and testing of the water. In addition we carried out socio-economic research to find out the impact on the local community of the imbalance caused by anthropogenic activities in the watershed upstream from the Bay. Our research established that the Bay of Bacorehuis is contaminated by organic matter, bacteria coliforms, pesticides and mercury due to the discharge of surplus runoff generated by irrigation of farmlands into drainage networks as well as the discharge of untreated industrial and domestic wastewater form more than 24,000 inhabitants. The main contaminants detected in the water bodies were organic matter, faecal coliforms, mercury, dimethoate, endosulfan, heptachlor, DDE, DDT, organonitrogen, synthetic pyrethroid, chlorothalonil, ethion, endosulfan, diazinon, malathion and chlorpyrifos. Contaminants in sediments included the pesticides endosulfan, heptachlor, DDE, DDT, organophosphates, organonitrogen and synthetic pyrethroids. Natural water courses have been highly modified

Geology of the Teakettle Creek watersheds

Science.gov (United States)

Robert S. LaMotte

1937-01-01

The Teakettle Creek Experimental Watersheds lie for the most part on quartzites of probable Triassic age. However one of the triplicate drainages has a considerable acreage developed on weathered granodiorite. Topography is relatively uniform and lends itself to triplicate watershed studies. Locations for dams are suitable if certain engineering precautions...

Identification of largemouth bass virus in the introduced Northern Snakehead inhabiting the Chesapeake Bay watershed.

Science.gov (United States)

Iwanowicz, L; Densmore, C; Hahn, C; McAllister, P; Odenkirk, J

2013-09-01

The Northern Snakehead Channa argus is an introduced species that now inhabits the Chesapeake Bay. During a preliminary survey for introduced pathogens possibly harbored by these fish in Virginia waters, a filterable agent was isolated from five specimens that produced cytopathic effects in BF-2 cells. Based on PCR amplification and partial sequencing of the major capsid protein (MCP), DNA polymerase (DNApol), and DNA methyltransferase (Mtase) genes, the isolates were identified as Largemouth Bass virus (LMBV). Nucleotide sequences of the MCP (492 bp) and DNApol (419 pb) genes were 100% identical to those of LMBV. The nucleotide sequence of the Mtase (206 bp) gene was 99.5% identical to that of LMBV, and the single nucleotide substitution did not lead to a predicted amino acid coding change. This is the first report of LMBV from the Northern Snakehead, and provides evidence that noncentrarchid fishes may be susceptible to this virus.

Identification of largemouth bass virus in the introduced Northern snakehead inhabiting the Cheasapeake Bay watershed

Science.gov (United States)

Iwanowicz, Luke R.; Densmore, Christine L.; Hahn, Cassidy M.; McAllister, Phillip; Odenkirk, John

2013-01-01

The Northern Snakehead Channa argus is an introduced species that now inhabits the Chesapeake Bay. During a preliminary survey for introduced pathogens possibly harbored by these fish in Virginia waters, a filterable agent was isolated from five specimens that produced cytopathic effects in BF-2 cells. Based on PCR amplification and partial sequencing of the major capsid protein (MCP), DNA polymerase (DNApol), and DNA methyltransferase (Mtase) genes, the isolates were identified as Largemouth Bass virus (LMBV). Nucleotide sequences of the MCP (492 bp) and DNApol (419 pb) genes were 100% identical to those of LMBV. The nucleotide sequence of the Mtase (206 bp) gene was 99.5% identical to that of LMBV, and the single nucleotide substitution did not lead to a predicted amino acid coding change. This is the first report of LMBV from the Northern Snakehead, and provides evidence that noncentrarchid fishes may be susceptible to this virus.

Valuing the effects of hydropower development on watershed ecosystem services: Case studies in the Jiulong River Watershed, Fujian Province, China

Science.gov (United States)

Wang, Guihua; Fang, Qinhua; Zhang, Luoping; Chen, Weiqi; Chen, Zhenming; Hong, Huasheng

2010-02-01

Hydropower development brings many negative impacts on watershed ecosystems which are not fully integrated into current decision-making largely because in practice few accept the cost and benefit beyond market. In this paper, a framework was proposed to valuate the effects on watershed ecosystem services caused by hydropower development. Watershed ecosystem services were classified into four categories of provisioning, regulating, cultural and supporting services; then effects on watershed ecosystem services caused by hydropower development were identified to 21 indicators. Thereafter various evaluation techniques including the market value method, opportunity cost approach, project restoration method, travel cost method, and contingent valuation method were determined and the models were developed to valuate these indicators reflecting specific watershed ecosystem services. This approach was applied to three representative hydropower projects (Daguan, Xizaikou and Tiangong) of Jiulong River Watershed in southeast China. It was concluded that for hydropower development: (1) the value ratio of negative impacts to positive benefits ranges from 64.09% to 91.18%, indicating that the negative impacts of hydropower development should be critically studied during its environmental administration process; (2) the biodiversity loss and water quality degradation (together accounting for 80-94%) are the major negative impacts on watershed ecosystem services; (3) the average environmental cost per unit of electricity is up to 0.206 Yuan/kW h, which is about three quarters of its on-grid power tariff; and (4) the current water resource fee accounts for only about 4% of its negative impacts value, therefore a new compensatory method by paying for ecosystem services is necessary for sustainable hydropower development. These findings provide a clear picture of both positive and negative effects of hydropower development for decision-makers in the monetary term, and also provide a

eBay.com

DEFF Research Database (Denmark)

Engholm, Ida

2014-01-01

Celebrated as one of the leading and most valuable brands in the world, eBay has acquired iconic status on par with century-old brands such as Coca-Cola and Disney. The eBay logo is now synonymous with the world’s leading online auction website, and its design is associated with the company...

Discharge between San Antonio Bay and Aransas Bay, southern Gulf Coast, Texas, May-September 1999

Science.gov (United States)

East, Jeffery W.

2001-01-01

Along the Gulf Coast of Texas, many estuaries and bays are important habitat and nurseries for aquatic life. San Antonio Bay and Aransas Bay, located about 50 and 30 miles northeast, respectively, of Corpus Christi, are two important estuarine nurseries on the southern Gulf Coast of Texas (fig. 1). According to the Texas Parks and Wildlife Department, “Almost 80 percent of the seagrasses [along the Texas Gulf Coast] are located in the Laguna Madre, an estuary that begins just south of Corpus Christi Bay and runs southward 140 miles to South Padre Island. Most of the remaining seagrasses, about 45,000 acres, are located in the heavily traveled San Antonio, Aransas and Corpus Christi Bay areas” (Shook, 2000).Population growth has led to greater demands on water supplies in Texas. The Texas Water Development Board, the Texas Parks and Wildlife Department, and the Texas Natural Resource Conservation Commission have the cooperative task of determining inflows required to maintain the ecological health of the State’s streams, rivers, bays, and estuaries. To determine these inflow requirements, the three agencies collect data and conduct studies on the need for instream flows and freshwater/ saline water inflows to Texas estuaries.To assist in the determination of freshwater inflow requirements, the U.S. Geological Survey (USGS), in cooperation with the Texas Water Development Board, conducted a hydrographic survey of discharge (flow) between San Antonio Bay and Aransas Bay during the period May–September 1999. Automated instrumentation and acoustic technology were used to maximize the amount and quality of data that were collected, while minimizing personnel requirements. This report documents the discharge measured at two sites between the bays during May–September 1999 and describes the influences of meteorologic (wind and tidal) and hydrologic (freshwater inflow) conditions on discharge between the two bays. The movement of water between the bays is

Benthic biogeochemical cycling, nutrient stoichiometry, and carbon and nitrogen mass balances in a eutrophic freshwater bay

Science.gov (United States)

Klump, J.V.; Fitzgerald, S.A.; Waplesa, J.T.

2009-01-01

Green Bay, while representing only ,7% of the surface area and ??1.4% of the volume of Lake Michigan, contains one-third of the watershed of the lake, and receives approximately one-third of the total nutrient loading to the Lake Michigan basin, largely from the Fox River at the southern end of the bay. With a history of eutrophic conditions dating back nearly a century, the southern portion of the bay behaves as an efficient nutrient and sediment trap, sequestering much of the annual carbon and nitrogen input within sediments accumulating at up to 1 cm per year. Depositional fluxes of organic matter varied from ??0.1 mol C m-2 yr-1 to >10 mol C m-2 yr-1 and were both fairly uniform in stoichiometric composition and relatively labile. Estimates of benthic recycling derived from pore-water concentration gradients, whole-sediment incubation experiments, and deposition-burial models of early diagenesis yielded an estimated 40% of the carbon and 50% of the nitrogen recycled back into the overlying water. Remineralization was relatively rapid with ??50% of the carbon remineralized within <15 yr of deposition, and a mean residence time for metabolizable carbon and nitrogen in the sediments of 20 yr. On average, organic carbon regeneration occurred as 75% CO2, 15% CH4, and 10% dissolved organic carbon (DOC). Carbon and nitrogen budgets for the southern bay were based upon direct measurements of inputs and burial and upon estimates of export and production derived stoichiometrically from a coupled phosphorus budget. Loadings of organic carbon from rivers were ??3.7 mol m-2 yr-1, 80% in the form of DOC and 20% as particulate organic carbon. These inputs were lost through export to northern Green Bay and Lake Michigan (39%), through sediment burial (26%), and net CO2 release to the atmosphere (35%). Total carbon input, including new production, was 4.54 mol m-2 C yr-1, equivalent to ??10% of the gross annual primary production. Nitrogen budget terms were less well quantified

Bringing Science to Life for Students, Teachers and the Community

Science.gov (United States)

Pratt, K.

2012-04-01

Bringing Science to Life for Students, Teachers and the Community Prior to 2008, 5th grade students at two schools of the New Haven Unified School District consistently scored in the bottom 20% of the California State Standards Test for science. Teachers in the upper grades reported not spending enough time teaching science, which is attributed to lack of time, resources or knowledge of science. A proposal was written to the National Oceanic and Atmospheric Administration's Bay Watershed Education Grant program and funding was received for Bringing Science to Life for Students, Teachers and the Community to address these concerns and instill a sense of stewardship in our students. This program engages and energizes students in learning science and the protection of the SF Bay Watershed, provides staff development for teachers, and educates the community about conservation of our local watershed. The project includes a preparation phase, outdoor phase, an analysis and reporting phase, and teacher training and consists of two complete units: 1) The San Francisco Bay Watershed Unit and 2) the Marine Environment Unit. At the end of year 5, our teachers were teaching more science, the community was engaged in conservation of the San Francisco Bay Watershed and most importantly, student scores increased on the California Science Test at one site by over 121% and another site by 152%.

5. Basin assessment and watershed analysis

Science.gov (United States)

Leslie M. Reid; Robert R. Ziemer

1994-01-01

Abstract - Basin assessment is an important component of the President's Forest Plan, yet it has received little attention. Basin assessments are intended both to guide watershed analyses by specifying types of issues and interactions that need to be understood, and, eventually, to integrate the results of watershed analyses occurring within a river basin....

Turbidity Threshold sampling in watershed research

Science.gov (United States)

Rand Eads; Jack Lewis

2003-01-01

Abstract - When monitoring suspended sediment for watershed research, reliable and accurate results may be a higher priority than in other settings. Timing and frequency of data collection are the most important factors influencing the accuracy of suspended sediment load estimates, and, in most watersheds, suspended sediment transport is dominated by a few, large...

Watershed Planning Basins

Data.gov (United States)

Vermont Center for Geographic Information — The Watershed Planning Basin layer is part of a larger dataset contains administrative boundaries for Vermont's Agency of Natural Resources. The dataset includes...

Classification using Hierarchical Naive Bayes models

DEFF Research Database (Denmark)

Langseth, Helge; Dyhre Nielsen, Thomas

2006-01-01

Classification problems have a long history in the machine learning literature. One of the simplest, and yet most consistently well-performing set of classifiers is the Naïve Bayes models. However, an inherent problem with these classifiers is the assumption that all attributes used to describe......, termed Hierarchical Naïve Bayes models. Hierarchical Naïve Bayes models extend the modeling flexibility of Naïve Bayes models by introducing latent variables to relax some of the independence statements in these models. We propose a simple algorithm for learning Hierarchical Naïve Bayes models...

Urban Greening Bay Area

Science.gov (United States)

Information about the San Francisco Bay Water Quality Project (SFBWQP) Urban Greening Bay Area, a large-scale effort to re-envision urban landscapes to include green infrastructure (GI) making communities more livable and reducing stormwater runoff.

Concentration of PSP (Paralytic Shellfish Poisoning) Toxin On Shellfish From Inner Ambon Bay and Kao Bay North Halmahera

Science.gov (United States)

Pello, F. S.; Haumahu, S.; Huliselan, N. V.; Tuapattinaja, M. A.

2017-10-01

The Inner Ambon Bay and Kao Bay have potential on fisheries resources which one of them is molluscs. Molluscs especially for class bivalve have economical values and are consumed by coastal community. The research had been done to analyze saxitoxin (STX) concentration on bivalves from Kao Bay and Inner Ambon Bay. The Saxitoxin Elisa Test Kit Protocol was used to determine saxitoxin concentration. The measurement showed that the highest concentration of saxitoxin (392.42 µg STXeq/100g shellfish meat) was Gafrarium tumidum from Ambon Bay, whereas concentration of saxitoxin (321.83 µg STXeq/100g shellfish meat) was Mactra mera from Kao Bay

Relationship of land use to water quality in the Chesapeake Bay region. [water sampling and photomapping river basins

Science.gov (United States)

Correll, D. L.

1978-01-01

Both the proportions of the various land use categories present on each watershed and the specific management practices in use in each category affect the quality of runoff waters, and the water quality of the Bay. Several permanent and portable stations on various Maryland Rivers collect volume-integrated water samples. All samples are analyzed for a series of nutrient, particulate, bacterial, herbicide, and heavy metal parameters. Each basin is mapped with respect to land use by the analysis of low-elevation aerial photos. Analyses are verified and adjusted by ground truth surveys. Data are processed and stored in the Smithsonian Institution data bank. Land use categories being investigated include forests/old fields, pastureland, row crops, residential areas, upland swamps, and tidal marshes.

Marine littoral diatoms from the Gordon’s bay region of False Bay, Cape Province, South Africa

CSIR Research Space (South Africa)

Giffen, MH

1971-01-01

Full Text Available and Comic/i for Scientific and Industrial Research, Pretoria (Received: 5.2. 1970) The Gordon?s Bay region occupies the north western corner of False Bay, a large rectangular bay, bounded on the west by the Cape Peninsula ending at Cape Point...

Description of gravity cores from San Pablo Bay and Carquinez Strait, San Francisco Bay, California

Science.gov (United States)

Woodrow, Donald L.; John L. Chin,; Wong, Florence L.; Fregoso, Theresa A.; Jaffe, Bruce E.

2017-06-27

Seventy-two gravity cores were collected by the U.S. Geological Survey in 1990, 1991, and 2000 from San Pablo Bay and Carquinez Strait, California. The gravity cores collected within San Pablo Bay contain bioturbated laminated silts and sandy clays, whole and broken bivalve shells (mostly mussels), fossil tube structures, and fine-grained plant or wood fragments. Gravity cores from the channel wall of Carquinez Strait east of San Pablo Bay consist of sand and clay layers, whole and broken bivalve shells (less than in San Pablo Bay), trace fossil tubes, and minute fragments of plant material.

[Watershed water environment pollution models and their applications: a review].

Science.gov (United States)

Zhu, Yao; Liang, Zhi-Wei; Li, Wei; Yang, Yi; Yang, Mu-Yi; Mao, Wei; Xu, Han-Li; Wu, Wei-Xiang

2013-10-01

Watershed water environment pollution model is the important tool for studying watershed environmental problems. Through the quantitative description of the complicated pollution processes of whole watershed system and its parts, the model can identify the main sources and migration pathways of pollutants, estimate the pollutant loadings, and evaluate their impacts on water environment, providing a basis for watershed planning and management. This paper reviewed the watershed water environment models widely applied at home and abroad, with the focuses on the models of pollutants loading (GWLF and PLOAD), water quality of received water bodies (QUAL2E and WASP), and the watershed models integrated pollutant loadings and water quality (HSPF, SWAT, AGNPS, AnnAGNPS, and SWMM), and introduced the structures, principles, and main characteristics as well as the limitations in practical applications of these models. The other models of water quality (CE-QUAL-W2, EFDC, and AQUATOX) and watershed models (GLEAMS and MIKE SHE) were also briefly introduced. Through the case analysis on the applications of single model and integrated models, the development trend and application prospect of the watershed water environment pollution models were discussed.

Spatiotemporal variations in the abundance and composition of bulk and chromophoric dissolved organic matter in seasonally hypoxia-influenced Green Bay, Lake Michigan, USA.

Science.gov (United States)

DeVilbiss, Stephen E; Zhou, Zhengzhen; Klump, J Val; Guo, Laodong

2016-09-15

Green Bay, Lake Michigan, USA, is the largest freshwater estuary in the Laurentian Great Lakes and receives disproportional terrestrial inputs as a result of a high watershed to bay surface area ratio. While seasonal hypoxia and the formation of "dead zones" in Green Bay have received increasing attention, there are no systematic studies on the dynamics of dissolved organic matter (DOM) and its linkage to the development of hypoxia. During summer 2014, bulk dissolved organic carbon (DOC) analysis, UV-vis spectroscopy, and fluorescence excitation-emission matrices (EEMs) coupled with PARAFAC analysis were used to quantify the abundance, composition and source of DOM and their spatiotemporal variations in Green Bay, Lake Michigan. Concentrations of DOC ranged from 202 to 571μM-C (average=361±73μM-C) in June and from 279 to 610μM-C (average=349±64μM-C) in August. In both months, absorption coefficient at 254nm (a254) was strongly correlated to bulk DOC and was most abundant in the Fox River, attesting a dominant terrestrial input. Non-chromophoric DOC comprised, on average, ~32% of bulk DOC in June with higher terrestrial DOM and ~47% in August with higher aquagenic DOM, indicating that autochthonous and more degraded DOM is of lower optical activity. PARAFAC modeling on EEM data resulted in four major fluorescent DOM components, including two terrestrial humic-like, one aquagenic humic-like, and one protein-like component. Variations in the abundance of DOM components further supported changes in DOM sources. Mixing behavior of DOM components also indicated that while bulk DOM behaved quasi-conservatively, significant compositional changes occurred during transport from the Fox River to the open bay. Copyright © 2016 Elsevier B.V. All rights reserved.

Cumulative watershed effects: a research perspective

Science.gov (United States)

Leslie M. Reid; Robert R. Ziemer

1989-01-01

A cumulative watershed effect (CWE) is any response to multiple land-use activities that is caused by, or results in, altered watershed function. The CWE issue is politically defined, as is the significance of particular impacts. But the processes generating CWEs are the traditional focus of geomorphology and ecology, and have thus been studied for decades. The CWE...

Watershed and Economic Data InterOperability (WEDO): Facilitating Discovery, Evaluation and Integration through the Sharing of Watershed Modeling Data

Science.gov (United States)

Watershed and Economic Data InterOperability (WEDO) is a system of information technologies designed to publish watershed modeling studies for reuse. WEDO facilitates three aspects of interoperability: discovery, evaluation and integration of data. This increased level of interop...

Subdivision of Texas watersheds for hydrologic modeling.

Science.gov (United States)

2009-06-01

The purpose of this report is to present a set of findings and examples for subdivision of watersheds for hydrologic modeling. Three approaches were used to examine the impact of watershed subdivision on modeled hydrologic response: (1) An equal-area...

Stormwater Impaired Watersheds

Data.gov (United States)

Vermont Center for Geographic Information — Stormwater impaired watersheds occuring on both the Priority Waters (Part D - Completed TMDL) and 303(d) list of waters (Part A - need TMDL) The Vermont State...

Impacts of forest changes on hydrology: a case study of large watersheds in the upper reaches of Minjiang River watershed in China

Science.gov (United States)

Cui, X.; Liu, S.; Wei, X.

2012-11-01

Quantifying the effects of forest changes on hydrology in large watersheds is important for designing forest or land management and adaptation strategies for watershed ecosystem sustainability. Minjiang River watershed, located in the upper reach of the Yangtze River basin, plays a strategic role in the environmental protection and economic and social well-being for both the watershed and the entire Yangtze River basin. The watershed lies in the transition zone from Sichuan Basin to Qinghai-Tibet Plateau with a size of 24 000 km2. Due to its strategic significance, severe historic deforestation and high sensitivity to climate change, the watershed has long been recognized as one of the highest priority watersheds in China for scientific research and resource management. The purpose of this review paper is to provide a state-of-the-art summary on what we have learned from several recently completed research programs (one of them known as "973 of the China National Major Fundamental Science" from 2002 to 2008). This summary paper focused on how land cover or forest change affected hydrology at both forest stand and watershed scales in this large watershed. Inclusion of two different spatial scales is useful, because the results from a small spatial scale (e.g. forest stand level) can help interpret the findings on a large spatial scale. Our review suggests that historic forest harvesting or land cover change has caused significant water yield increase due to reduction of forest canopy interception and evapotranspiration caused by removal of forest vegetation on both spatial scales. The impact magnitude caused by forest harvesting indicates that the hydrological effects of forest or land cover changes can be as important as those caused by climate change, while the opposite impact directions suggest their offsetting effects on water yield in the Minjiang River watershed. In addition, different types of forests have different magnitudes of evapotranspiration (ET), with

Impacts of forest changes on hydrology: a case study of large watersheds in the upper reaches of Minjiang River watershed in China

Directory of Open Access Journals (Sweden)

X. Cui

2012-11-01

Full Text Available Quantifying the effects of forest changes on hydrology in large watersheds is important for designing forest or land management and adaptation strategies for watershed ecosystem sustainability. Minjiang River watershed, located in the upper reach of the Yangtze River basin, plays a strategic role in the environmental protection and economic and social well-being for both the watershed and the entire Yangtze River basin. The watershed lies in the transition zone from Sichuan Basin to Qinghai-Tibet Plateau with a size of 24 000 km². Due to its strategic significance, severe historic deforestation and high sensitivity to climate change, the watershed has long been recognized as one of the highest priority watersheds in China for scientific research and resource management. The purpose of this review paper is to provide a state-of-the-art summary on what we have learned from several recently completed research programs (one of them known as "973 of the China National Major Fundamental Science" from 2002 to 2008. This summary paper focused on how land cover or forest change affected hydrology at both forest stand and watershed scales in this large watershed. Inclusion of two different spatial scales is useful, because the results from a small spatial scale (e.g. forest stand level can help interpret the findings on a large spatial scale. Our review suggests that historic forest harvesting or land cover change has caused significant water yield increase due to reduction of forest canopy interception and evapotranspiration caused by removal of forest vegetation on both spatial scales. The impact magnitude caused by forest harvesting indicates that the hydrological effects of forest or land cover changes can be as important as those caused by climate change, while the opposite impact directions suggest their offsetting effects on water yield in the Minjiang River watershed. In addition, different types of forests have different magnitudes of

75 FR 15343 - Regulated Navigation Area: Narragansett Bay, RI and Mount Hope Bay, RI and MA, Including the...

Science.gov (United States)

2010-03-29

...: Narragansett Bay, RI and Mount Hope Bay, RI and MA, Including the Providence River and Taunton River AGENCY... River and Mount Hope Bay in the vicinity of the two Brightman Street bridges have not been adopted and... Island and Mt. Hope Bay, MA.'' The notice was prompted primarily by two events: (1) The U.S. Army Corps...

Watershed Modeling Applications with the Open-Access Modular Distributed Watershed Educational Toolbox (MOD-WET) and Introductory Hydrology Textbook

Science.gov (United States)

Huning, L. S.; Margulis, S. A.

2014-12-01

Traditionally, introductory hydrology courses focus on hydrologic processes as independent or semi-independent concepts that are ultimately integrated into a watershed model near the end of the term. When an "off-the-shelf" watershed model is introduced in the curriculum, this approach can result in a potential disconnect between process-based hydrology and the inherent interconnectivity of processes within the water cycle. In order to curb this and reduce the learning curve associated with applying hydrologic concepts to complex real-world problems, we developed the open-access Modular Distributed Watershed Educational Toolbox (MOD-WET). The user-friendly, MATLAB-based toolbox contains the same physical equations for hydrological processes (i.e. precipitation, snow, radiation, evaporation, unsaturated flow, infiltration, groundwater, and runoff) that are presented in the companion e-textbook (http://aqua.seas.ucla.edu/margulis_intro_to_hydro_textbook.html) and taught in the classroom. The modular toolbox functions can be used by students to study individual hydrologic processes. These functions are integrated together to form a simple spatially-distributed watershed model, which reinforces a holistic understanding of how hydrologic processes are interconnected and modeled. Therefore when watershed modeling is introduced, students are already familiar with the fundamental building blocks that have been unified in the MOD-WET model. Extensive effort has been placed on the development of a highly modular and well-documented code that can be run on a personal computer within the commonly-used MATLAB environment. MOD-WET was designed to: 1) increase the qualitative and quantitative understanding of hydrological processes at the basin-scale and demonstrate how they vary with watershed properties, 2) emphasize applications of hydrologic concepts rather than computer programming, 3) elucidate the underlying physical processes that can often be obscured with a complicated

Landslides and sediment budgets in four watersheds in eastern Puerto Rico: Chapter F in Water quality and landscape processes of four watersheds in eastern Puerto Rico

Science.gov (United States)

Larsen, Matthew C.; Murphy, Sheila F.; Stallard, Robert F.

2012-01-01

The low-latitude regions of the Earth are undergoing profound, rapid landscape change as forests are converted to agriculture to support growing population. Understanding the effects of these land-use changes requires analysis of watershed-scale geomorphic processes to better inform and manage this usually disorganized process. The investigation of hillslope erosion and the development of sediment budgets provides essential information for resource managers. Four small, montane, humid-tropical watersheds in the Luquillo Experimental Forest and nearby Río Grande de Loíza watershed, Puerto Rico (18° 20' N., 65° 45' W.), were selected to compare and contrast the geomorphic effects of land use and bedrock geology. Two of the watersheds are underlain largely by resistant Cretaceous volcaniclastic rocks but differ in land use and mean annual runoff: the Mameyes watershed, with predominantly primary forest cover and runoff of 2,750 millimeters per year, and the Canóvanas watershed, with mixed secondary forest and pasture and runoff of 970 millimeters per year. The additional two watersheds are underlain by relatively erodible granitic bedrock: the forested Icacos watershed, with runoff of 3,760 millimeters per year and the agriculturally developed Cayaguás watershed, with a mean annual runoff of 1,620 millimeters per year. Annual sediment budgets were estimated for each watershed using landslide, slopewash, soil creep, treethrow, suspended sediment, and streamflow data. The budgets also included estimates of sediment storage in channel beds, bars, floodplains, and in colluvial deposits. In the two watersheds underlain by volcaniclastic rocks, the forested Mameyes and the developed Canóvanas watersheds, landslide frequency (0.21 and 0.04 landslides per square kilometer per year, respectively), slopewash (5 and 30 metric tons per square kilometer per year), and suspended sediment yield (325 and 424 metric tons per square kilometer per year), were lower than in the

A Stochastic Water Balance Framework for Lowland Watersheds

Science.gov (United States)

Thompson, Sally; MacVean, Lissa; Sivapalan, Murugesu

2017-11-01

The water balance dynamics in lowland watersheds are influenced not only by local hydroclimatic controls on energy and water availability, but also by imports of water from the upstream watershed. These imports result in a stochastic extent of inundation in lowland watersheds that is determined by the local flood regime, watershed topography, and the rate of loss processes such as drainage and evaporation. Thus, lowland watershed water balances depend on two stochastic processes—rainfall and local inundation dynamics. Lowlands are high productivity environments that are disproportionately associated with urbanization, high productivity agriculture, biodiversity, and flood risk. Consequently, they are being rapidly altered by human development—generally with clear economic and social motivation—but also with significant trade-offs in ecosystem services provision, directly related to changes in the components and variability of the lowland water balance. We present a stochastic framework to assess the lowland water balance and its sensitivity to two common human interventions—replacement of native vegetation with alternative land uses, and construction of local flood protection levees. By providing analytical solutions for the mean and PDF of the water balance components, the proposed framework provides a mechanism to connect human interventions to hydrologic outcomes, and, in conjunction with ecosystem service production estimates, to evaluate trade-offs associated with lowland watershed development.

Watershed analysis on federal lands of the Pacific northwest

Science.gov (United States)

Leslie M. Reid; Robert R. Ziemer; Michael J. Furniss

1994-01-01

Abstract - Watershed analysis-the evaluation of processes that affect ecosystems and resources in a watershed-is now being carried out by Federal land-management and regulatory agencies on Federal lands of the Pacific Northwest. Methods used differ from those of other implementations of watershed analysis because objectives and opportunities differ. In particular,...

Ecosystem services of human-dominated watersheds and land use influences: a case study from the Dianchi Lake watershed in China.

Science.gov (United States)

Hou, Ying; Li, Bo; Müller, Felix; Chen, Weiping

2016-11-01

Watersheds provide multiple ecosystem services. Ecosystem service assessment is a promising approach to investigate human-environment interaction at the watershed scale. The spatial characteristics of ecosystem services are closely related to land use statuses in human-dominated watersheds. This study aims to investigate the effects of land use on the spatial variations of ecosystem services at the Dianchi Lake watershed in Southwest China. We investigated the spatial variations of six ecosystem services-food supply, net primary productivity (NPP), habitat quality, evapotranspiration, water yield, and nitrogen retention. These services were selected based on their significance at the Dianchi Lake watershed and the availability of their data. The quantification of these services was based on modeling, value transference, and spatial analysis in combination with biophysical and socioeconomic data. Furthermore, we calculated the values of ecosystem services provided by different land use types and quantified the correlations between ecosystem service values and land use area proportions. The results show considerable spatial variations in the six ecosystem services associated with land use influences in the Dianchi Lake watershed. The cropland and forest land use types had predominantly positive influences on food productivity and NPP, respectively. The rural residential area and forest land use types reduced and enhanced habitat quality, respectively; these influences were identical to those of evapotranspiration. Urban area and rural residential area exerted significantly positive influences on water yield. In contrast, water yield was negatively correlated with forest area proportion. Finally, cropland and forest had significantly positive and negative influences, respectively, on nitrogen retention. Our study emphasizes the importance of consideration of the influences from land use composition and distribution on ecosystem services for managing the ecosystems of

Nitrate in watersheds: straight from soils to streams?

Science.gov (United States)

Sudduth, Elizabeth B.; Perakis, Steven S.; Bernhardt, Emily S.

2013-01-01

Human activities are rapidly increasing the global supply of reactive N and substantially altering the structure and hydrologic connectivity of managed ecosystems. There is long-standing recognition that N must be removed along hydrologic flowpaths from uplands to streams, yet it has proven difficult to assess the generality of this removal across ecosystem types, and whether these patterns are influenced by land-use change. To assess how well upland nitrate (NO3-) loss is reflected in stream export, we gathered information from >50 watershed biogeochemical studies that reported nitrate concentrations ([NO3-]) for stream water and for either upslope soil solution or groundwater NO3- to examine whether stream export of NO3- accurately reflects upland NO3- losses. In this dataset, soil solution and streamwater [NO3-] were correlated across 40 undisturbed forest watersheds, with streamwater [NO3-] typically half (median = 50%) soil solution [NO3-]. A similar relationship was seen in 10 disturbed forest watersheds. However, for 12 watersheds with significant agricultural or urban development, the intercept and slope were both significantly higher than the relationship seen in forest watersheds. Differences in concentration between soil solution or groundwater and stream water may be attributed to biological uptake, microbial processes including denitrification, and/or preferential flow routing. The results of this synthesis are consistent with the hypotheses that undisturbed watersheds have a significant capacity to remove nitrate after it passes below the rooting zone and that land use changes tend to alter the efficiency or the length of watershed flowpaths, leading to reductions in nitrate removal and increased stream nitrate concentrations.

Daily Streamflow Predictions in an Ungauged Watershed in Northern California Using the Precipitation-Runoff Modeling System (PRMS): Calibration Challenges when nearby Gauged Watersheds are Hydrologically Dissimilar

Science.gov (United States)

Dhakal, A. S.; Adera, S.

2017-12-01

Accurate daily streamflow prediction in ungauged watersheds with sparse information is challenging. The ability of a hydrologic model calibrated using nearby gauged watersheds to predict streamflow accurately depends on hydrologic similarities between the gauged and ungauged watersheds. This study examines daily streamflow predictions using the Precipitation-Runoff Modeling System (PRMS) for the largely ungauged San Antonio Creek watershed, a 96 km2 sub-watershed of the Alameda Creek watershed in Northern California. The process-based PRMS model is being used to improve the accuracy of recent San Antonio Creek streamflow predictions generated by two empirical methods. Although San Antonio Creek watershed is largely ungauged, daily streamflow data exists for hydrologic years (HY) 1913 - 1930. PRMS was calibrated for HY 1913 - 1930 using streamflow data, modern-day land use and PRISM precipitation distribution, and gauged precipitation and temperature data from a nearby watershed. The PRMS model was then used to generate daily streamflows for HY 1996-2013, during which the watershed was ungauged, and hydrologic responses were compared to two nearby gauged sub-watersheds of Alameda Creek. Finally, the PRMS-predicted daily flows between HY 1996-2013 were compared to the two empirically-predicted streamflow time series: (1) the reservoir mass balance method and (2) correlation of historical streamflows from 80 - 100 years ago between San Antonio Creek and a nearby sub-watershed located in Alameda Creek. While the mass balance approach using reservoir storage and transfers is helpful for estimating inflows to the reservoir, large discrepancies in daily streamflow estimation can arise. Similarly, correlation-based predicted daily flows which rely on a relationship from flows collected 80-100 years ago may not represent current watershed hydrologic conditions. This study aims to develop a method of streamflow prediction in the San Antonio Creek watershed by examining PRMS

DNR Watersheds - DNR Level 04 - HUC 08 - Majors

Data.gov (United States)

Minnesota Department of Natural Resources — These data consists of 81 watershed delineations in one seamless dataset of drainage areas called Minnesota Department of Natural Resources (DNR) Major Watersheds....

Sediment sources in an urbanizing, mixed land-use watershed

Science.gov (United States)

Nelson, Erin J.; Booth, Derek B.

2002-07-01

The Issaquah Creek watershed is a rapidly urbanizing watershed of 144 km 2 in western Washington, where sediment aggradation of the main channel and delivery of fine sediment into a large downstream lake have raised increasingly frequent concerns over flooding, loss of fish habitat, and degraded water quality. A watershed-scale sediment budget was evaluated to determine the relative effects of land-use practices, including urbanization, on sediment supply and delivery, and to guide management responses towards the most effective source-reduction strategies. Human activity in the watershed, particularly urban development, has caused an increase of nearly 50% in the annual sediment yield, now estimated to be 44 tonnes km -2 yr -1. The main sources of sediment in the watershed are landslides (50%), channel-bank erosion (20%), and road-surface erosion (15%). This assessment characterizes the role of human activity in mixed-use watersheds such as this, and it demonstrates some of the key processes, particularly enhanced stream-channel erosion, by which urban development alters sediment loads.

Watershed restoration through remining in the Tangascootack Creek Watershed, Clinton County, Pennsylvania

International Nuclear Information System (INIS)

Skema, V.W.; Smith, M.W.; Bisko, D.C.; Dimatteo, M.

1998-01-01

The Pennsylvania Department of Environmental Protection and the Pennsylvania Geologic Survey are working together to remediate the effects of acid mine drainage. Remining of previously mined areas is a key component of a comprehensive strategy of improving water quality in polluted watersheds. In this new approach sites will be carefully selected on the basis of remaining coal reserves and overburden characteristics. One of the first watersheds targeted was the Tangascootack Creek watershed located in Clinton County near Lock Haven. The Geologic Survey agreed to provide geologic and coal resource maps for this previously unmapped area. This involved conducting field work examining rock exposures. Five cored holes were drilled, and core was examined to develop a geologic framework. Coals from these holes and from highwalls were chemically tested. Strata overlying the coal seams were analyzed using acid base accounting to determine their potential for generating acidity as well as alkalinity. Additional drill hole data and chemical analyses were collected from cooperating mining companies. This information was used to produce a geologic map showing coal crop lines and structure, coal thickness maps, mined-out area maps, overburden thickness maps, overburden geochemistry maps, strip ratio maps, and to estimate the extent of remaining coal reserves. Several significant geologic features were found in the course of mapping the watershed. One is the extreme variability in coal thickness and character of overburden rock. Another is the degree of relief found to be present on the Mississippian-Pennsylvanian unconformity. It is believed that this feature plays an important role in coal and high aluminum flint clay distribution regionally. And finally is the thick occurrence of Loyalhanna Formation calcareous sandstone which is providing a natural source of carbonate for the neutralization of acid mine drainage

Protect and Restore Red River Watershed, 2007-2008 Annual Report.

Energy Technology Data Exchange (ETDEWEB)

Bransford, Stephanie [Nez Perce Tribe Fisheries/Watershed Program

2009-05-04

The Nez Perce Tribe Department of Fisheries Resource Management, Watershed Division approaches watershed restoration with a ridge-top to ridge-top approach. The Nez Perce Tribe (NPT) and the Nez Perce National Forest (NPNF) have formed a partnership in completing watershed restoration activities, and through this partnership more work is accomplished by sharing funding and resources in our effort. The Nez Perce Tribe began watershed restoration projects within the Red River Watershed of the South Fork Clearwater River in 2001. Progress has been made in restoring the watershed through road decommissioning and culvert replacement. From completing a watershed assessment to two NEPA efforts and a final stream restoration design, we will begin the effort of restoring the mainstem channel of Red River to provide spawning and rearing habitat for anadromous and resident fish species. Roads have been surveyed and prioritized for removal or improvement as well as culverts being prioritized for replacement to accommodate fish passage throughout the watershed. Another major, and extremely, important component of this project is the Red River Meadow Conservation Easement. We have begun the process of pursuing a conservation easement on approximately 270 acres of prime meadow habitat (Red River runs through this meadow and is prime spawning and rearing habitat).

New efficient methods for calculating watersheds

International Nuclear Information System (INIS)

Fehr, E; Andrade, J S Jr; Herrmann, H J; Kadau, D; Moukarzel, C F; Da Cunha, S D; Da Silva, L R; Oliveira, E A

2009-01-01

We present an advanced algorithm for the determination of watershed lines on digital elevation models (DEMs) which is based on the iterative application of invasion percolation (IP). The main advantage of our method over previously proposed ones is that it has a sub-linear time-complexity. This enables us to process systems comprising up to 10 8 sites in a few CPU seconds. Using our algorithm we are able to demonstrate, convincingly and with high accuracy, the fractal character of watershed lines. We find the fractal dimension of watersheds to be D f = 1.211 ± 0.001 for artificial landscapes, D f = 1.10 ± 0.01 for the Alps and D f = 1.11 ± 0.01 for the Himalayas

Grays River Watershed and Biological Assessment Final Report 2006.

Energy Technology Data Exchange (ETDEWEB)

May, Christopher W.; McGrath, Kathleen E.; Geist, David R. [Pacific Northwest National Laboratory; Abbe, Timothy; Barton, Chase [Herrera Environmental Consultants, Inc.

2008-02-04

The Grays River Watershed and Biological Assessment was funded to address degradation and loss of spawning habitat for chum salmon (Onchorhynchus keta) and fall Chinook salmon (Onchoryhnchus tshawytscha). In 1999, the National Marine Fisheries Service listed lower Columbia River chum salmon as a threatened Evolutionarily Significant Unit (ESU) under the Endangered Species Act of 1973 (ESA). The Grays River watershed is one of two remaining significant chum salmon spawning locations in this ESU. Runs of Grays River chum and Chinook salmon have declined significantly during the past century, largely because of damage to spawning habitat associated with timber harvest and agriculture in the watershed. In addition, approximately 20-25% of the then-remaining chum salmon spawning habitat was lost during a 1999 channel avulsion that destroyed an important artificial spawning channel operated by the Washington Department of Fish and Wildlife (WDFW). Although the lack of stable, high-quality spawning habitat is considered the primary physical limitation on Grays River chum salmon production today, few data are available to guide watershed management and channel restoration activities. The objectives of the Grays River Watershed and Biological Assessment project were to (1) perform a comprehensive watershed and biological analysis, including hydrologic, geomorphic, and ecological assessments; (2) develop a prioritized list of actions that protect and restore critical chum and Chinook salmon spawning habitat in the Grays River based on comprehensive geomorphic, hydrologic, and stream channel assessments; and (3) gain a better understanding of chum and Chinook salmon habitat requirements and survival within the lower Columbia River and the Grays River. The watershed-based approach to river ecosystem restoration relies on a conceptual framework that describes general relationships between natural landscape characteristics, watershed-scale habitat-forming processes, aquatic

Grays River Watershed and Biological Assessment, 2006 Final Report.

Energy Technology Data Exchange (ETDEWEB)

May, Christopher; Geist, David [Pacific Northwest National Laboratory

2007-04-01

The Grays River Watershed and Biological Assessment was funded to address degradation and loss of spawning habitat for chum salmon (Onchorhynchus keta) and fall Chinook salmon (Onchoryhnchus tshawytscha). In 1999, the National Marine Fisheries Service listed lower Columbia River chum salmon as a threatened Evolutionarily Significant Unit (ESU) under the Endangered Species Act of 1973 (ESA). The Grays River watershed is one of two remaining significant chum salmon spawning locations in this ESU. Runs of Grays River chum and Chinook salmon have declined significantly during the past century, largely because of damage to spawning habitat associated with timber harvest and agriculture in the watershed. In addition, approximately 20-25% of the then-remaining chum salmon spawning habitat was lost during a 1999 channel avulsion that destroyed an important artificial spawning channel operated by the Washington Department of Fish and Wildlife (WDFW). Although the lack of stable, high-quality spawning habitat is considered the primary physical limitation on Grays River chum salmon production today, few data are available to guide watershed management and channel restoration activities. The objectives of the Grays River Watershed and Biological Assessment project were to (1) perform a comprehensive watershed and biological analysis, including hydrologic, geomorphic, and ecological assessments; (2) develop a prioritized list of actions that protect and restore critical chum and Chinook salmon spawning habitat in the Grays River based on comprehensive geomorphic, hydrologic, and stream channel assessments; and (3) gain a better understanding of chum and Chinook salmon habitat requirements and survival within the lower Columbia River and the Grays River. The watershed-based approach to river ecosystem restoration relies on a conceptual framework that describes general relationships between natural landscape characteristics, watershed-scale habitat-forming processes, aquatic

[Impact on nitrogen and phosphorous export of wetlands in Tianmu Lake watershed].

Science.gov (United States)

Li, Zhao-Fu; Liu, Hong-Yu; Li, Heng-Peng

2012-11-01

Focused on understanding the function of wetland in improving water quality, Pingqiao watershed and Zhongtian watershed in Tianmu Lake drinking water sources area were selected as the research region. We integrated remote sensing, GIS techniques with field investigation and chemical analysis to analyze the relationship between wetland and water quality in watershed scale. Results show: (1) There are many wetland patches in Pingqiao and Zhongtian watershed, wetlands patch densities were respectively 7.5 km(-2) and 7.1 km(-2). Wetlands widely distributed in the Pingqiao watershed with mostly located away from the river of 500 m, whereas wetlands relatively concentrated in the lower reach within 500 meters of riverside in Zhongtian watershed. (2) Nitrogen and phosphorus nutrient retention of wetland in watershed scale was significant. The annual mean TN and DTN concentration had a strong relationship with percent area of wetlands in Zhongtian watershed while the weakest relationship was found with TP and DTP concentrations, especially, the mean TN and DTN concentrations in spring and winter had the significantly negative relationship with wetland areas of watershed. The negative relationship was existed for nitrogen in autumn of Pingqiao watershed, which suggested that watersheds varying in area of wetlands have the different nutrient reducing efficiency in seasonal periods. (3) A certain number and area of wetland will improve river water quality in watershed scale, which can instruct water environment treatment. However, considering the complexity of nutrient transport processes in watershed, wetland-related factors such as area, location, density, ecosystem structure and watershed-related factors such as temporal interval, spatial scales, slope and land use will impact on the transport processes, and related theoretical and practical problems need further research.

Using Remotely Sensed Data and Hydrologic Models to Evaluate the Effects of Climate Change on Shallow Aquatic Ecosystems in the Mobile Bay, AL Estuary

Science.gov (United States)

Estes, M. G.; Al-Hamdan, M. Z.; Thom, R.; Judd, C.; Ellis, J.; Woodruff, D.; Quattrochi, D.; Rose, K.; Swann, R.

2012-12-01

Coastal systems in the northern Gulf of Mexico, including the Mobile Bay, AL estuary, are subject to increasing pressure from a variety of activities including climate change. Climate changes have a direct effect on the discharge of rivers that drain into Mobile Bay and adjacent coastal water bodies. The outflows change water quality (temperature, salinity, and sediment concentrations) in the shallow aquatic areas and affect ecosystem functioning. Mobile Bay is a vital ecosystem that provides habitat for many species of fauna and flora. Historically, submerged aquatic vegetation (SAV) and seagrasses were found in this area of the northern Gulf of Mexico; however the extent of vegetation has significantly decreased over the last 60 years. The objectives of this research are to determine: how climate changes affect runoff and water quality in the estuary and how these changes will affect habitat suitability for SAV and seagrasses. Our approach is to use watershed and hydrodynamic modeling to evaluate the impact of climate change on shallow water aquatic ecosystems in Mobile Bay and adjacent coastal areas. Remotely sensed Landsat data were used for current land cover land use (LCLU) model input and the data provided by Intergovernmental Panel on Climate Change (IPCC) of the future changes in temperature, precipitation, and sea level rise were used to create the climate scenarios for the 2025 and 2050 model simulations. Project results are being shared with Gulf coast stakeholders through the Gulf of Mexico Data Atlas to benefit coastal policy and climate change adaptation strategies.

Using Remotely Sensed Data and Hydrologic Models to Evaluate the Effects of Climate Change on Shallow Aquatic Ecosystems in the Mobile Bay, AL Estuary

Science.gov (United States)

Estes, M. G.; Al-Hamdan, M. Z.; Thom, R.; Judd, C.; Woodruff, D.; Ellis, J. T.; Quattrochi, D.; Swann, R.

2012-01-01

Coastal systems in the northern Gulf of Mexico, including the Mobile Bay, AL estuary, are subject to increasing pressure from a variety of activities including climate change. Climate changes have a direct effect on the discharge of rivers that drain into Mobile Bay and adjacent coastal water bodies. The outflows change water quality (temperature, salinity, and sediment concentrations) in the shallow aquatic areas and affect ecosystem functioning. Mobile Bay is a vital ecosystem that provides habitat for many species of fauna and flora. Historically, submerged aquatic vegetation (SAV) and seagrasses were found in this area of the northern Gulf of Mexico; however the extent of vegetation has significantly decreased over the last 60 years. The objectives of this research are to determine: how climate changes affect runoff and water quality in the estuary and how these changes will affect habitat suitability for SAV and seagrasses. Our approach is to use watershed and hydrodynamic modeling to evaluate the impact of climate change on shallow water aquatic ecosystems in Mobile Bay and adjacent coastal areas. Remotely sensed Landsat data were used for current land cover land use (LCLU) model input and the data provided by Intergovernmental Panel on Climate Change (IPCC) of the future changes in temperature, precipitation, and sea level rise were used to create the climate scenarios for the 2025 and 2050 model simulations. Project results are being shared with Gulf coast stakeholders through the Gulf of Mexico Data Atlas to benefit coastal policy and climate change adaptation strategies.

Bay breeze climatology at two sites along the Chesapeake bay from 1986-2010: Implications for surface ozone.

Science.gov (United States)

Stauffer, Ryan M; Thompson, Anne M

Hourly surface meteorological measurements were coupled with surface ozone (O 3 ) mixing ratio measurements at Hampton, Virginia and Baltimore, Maryland, two sites along the Chesapeake Bay in the Mid-Atlantic United States, to examine the behavior of surface O 3 during bay breeze events and quantify the impact of the bay breeze on local O 3 pollution. Analyses were performed for the months of May through September for the years 1986 to 2010. The years were split into three groups to account for increasingly stringent environmental regulations that reduced regional emissions of nitrogen oxides (NO x ): 1986-1994, 1995-2002, and 2003-2010. Each day in the 25-year record was marked either as a bay breeze day, a non-bay breeze day, or a rainy/cloudy day based on the meteorological data. Mean eight hour (8-h) averaged surface O 3 values during bay breeze events were 3 to 5 parts per billion by volume (ppbv) higher at Hampton and Baltimore than on non-bay breeze days in all year periods. Anomalies from mean surface O 3 were highest in the afternoon at both sites during bay breeze days in the 2003-2010 study period. In conjunction with an overall lowering of baseline O 3 after the 1995-2002 period, the percentage of total exceedances of the Environmental Protection Agency (EPA) 75 ppbv 8-h O 3 standard that occurred on bay breeze days increased at Hampton for 2003-2010, while remaining steady at Baltimore. These results suggest that bay breeze circulations are becoming more important to causing exceedance events at particular sites in the region, and support the hypothesis of Martins et al. (2012) that highly localized meteorology increasingly drives air quality events at Hampton.

Watershed Management Optimization Support Tool (WMOST) v3: Theoretical Documentation

Science.gov (United States)

The Watershed Management Optimization Support Tool (WMOST) is a decision support tool that facilitates integrated water management at the local or small watershed scale. WMOST models the environmental effects and costs of management decisions in a watershed context, accounting fo...

Monitoring of bird abundance and distribution at McKinley Bay and Hutchison Bay, Northwest Territories, 1981 to 1993

Energy Technology Data Exchange (ETDEWEB)

Cornish, B J; Dickson, D L

1994-04-01

McKinley Bay has been identified as a preferred site for a harbor to support oil and gas production in the Beaufort Sea. As the bay is a molting area for several species of diving duck, a study was initiated to monitor the effect of harbor development on birds using the bay. Baseline information on the natural annual fluctuations in the number of birds were collected for nine years at McKinley Bay and eight years at neighboring Hutchinson Bay, an area chosen as the control. The final report of the predevelopment phase of the monitoring study is presented, including results of the 1993 surveys and a summary of results of all years of surveys. There were significantly more diving ducks in McKinley Bay in early August 1990 to 1993, on average, than from 1981 to 1985. No statistically significant change in total diving ducks was noted at Hutchinson Bay. Numbers of species of divers varied substantially between years at the two bays but not to the same degree. Significantly more Pacific loons, red-throated loons, and northern pintails were recorded in the 1990-1993 surveys at McKinley Bay than in earlier surveys. Potential explanations for the large between-year fluctuations in diving duck numbers are discussed. The variations may be due to bird responses to changes in the physical environment or related to the limitations of the aerial survey techniques used. Because of the large natural fluctuations in numbers of molting diving ducks using these bays in early August, it will be difficult to detect future impacts of industrial disturbance, even when sources of survey bias are minimized. It is concluded that aerial surveys of molting diving ducks in the two bays are unsuitable for monitoring the effects of industrial development. 41 refs., 7 figs., 23 tabs.

Cloud GIS Based Watershed Management

Science.gov (United States)

Bediroğlu, G.; Colak, H. E.

2017-11-01

In this study, we generated a Cloud GIS based watershed management system with using Cloud Computing architecture. Cloud GIS is used as SAAS (Software as a Service) and DAAS (Data as a Service). We applied GIS analysis on cloud in terms of testing SAAS and deployed GIS datasets on cloud in terms of DAAS. We used Hybrid cloud computing model in manner of using ready web based mapping services hosted on cloud (World Topology, Satellite Imageries). We uploaded to system after creating geodatabases including Hydrology (Rivers, Lakes), Soil Maps, Climate Maps, Rain Maps, Geology and Land Use. Watershed of study area has been determined on cloud using ready-hosted topology maps. After uploading all the datasets to systems, we have applied various GIS analysis and queries. Results shown that Cloud GIS technology brings velocity and efficiency for watershed management studies. Besides this, system can be easily implemented for similar land analysis and management studies.

Segmentation by watersheds : definition and parallel implementation

NARCIS (Netherlands)

Roerdink, Jos B.T.M.; Meijster, Arnold

1997-01-01

The watershed algorithm is a method for image segmentation widely used in the area of mathematical morphology. In this paper we first address the problem of how to define watersheds. It is pointed out that various existing definitions are not equivalent. In particular we explain the differences

Default Bayes factors for ANOVA designs

NARCIS (Netherlands)

Rouder, Jeffrey N.; Morey, Richard D.; Speckman, Paul L.; Province, Jordan M.

2012-01-01

Bayes factors have been advocated as superior to p-values for assessing statistical evidence in data. Despite the advantages of Bayes factors and the drawbacks of p-values, inference by p-values is still nearly ubiquitous. One impediment to the adoption of Bayes factors is a lack of practical

Applying Spatially Distributed Rainfall to a Hydrological Model in a Tropical Watershed, Manoa Watershed, in Hawaii

Science.gov (United States)

Huang, Y. F.; Tsang, Y. P.

2017-12-01

Rainfall in Hawaii is characterized with high spatial and temporal variability. In the south side of Oahu, the Manoa watershed, with an area of 11 km2, has the annual maximum rainfall of 3900mm and the minimum rainfall of 1000 mm. Despite this high spatial heterogeneity, the rain gage network seems insufficiently capture this pattern. When simulating stream flow and predicting floods with hydrological models in Hawaii, the model performance is often unsatisfactory because of inadequate representation of rainfall data. Longman et al. (in prep.) have developed the spatially distributed daily rainfall across the Hawaiian Islands by applying ordinary kriging, yet these data have not been applied to hydrological models. In this study, we used the Soil and Water Assessment Tool (SWAT) model to assess the streamflow simulation by applying spatially-distributed rainfall in the Manoa watershed. We first used point daily-rainfall at Lyon Arboretum from National Center of Environmental Information (NCEI) as the uniform rainfall input. Secondly, we summarized sub-watershed mean rainfall from the daily spatial-statistical rainfall. Both rainfall data are available from 1999 to 2014. The SWAT was set up for five-year warm-up, nine-year calibration, and two-year validation. The model parameters were calibrated and validated with four U.S. Geological Survey stream gages. We compared the calibrated watershed parameters, characteristics, and assess the streamflow hydrographs from these two rainfall inputs. The differences and improvement of using spatially distributed rainfall input in SWAT were discussed. In addition to improving the model by the representation of rainfall, this study helped us having a better understanding of the watershed hydrological response in Hawaii.

77 FR 21890 - Drawbridge Operation Regulation; Sturgeon Bay Ship Canal, Sturgeon Bay, WI

Science.gov (United States)

2012-04-12

... Street and Maple-Oregon Bridges so vehicular traffic congestion would not develop on downtown Sturgeon... the efficient movement of vehicular traffic in Sturgeon Bay. The Sturgeon Bay Ship Canal is... experiences a significant increase in vehicular and vessel traffic during the peak tourist and navigation...

Fish Passage Assessment: Big Canyon Creek Watershed, Technical Report 2004.

Energy Technology Data Exchange (ETDEWEB)

Christian, Richard

2004-02-01

This report presents the results of the fish passage assessment as outlined as part of the Protect and Restore the Big Canyon Creek Watershed project as detailed in the CY2003 Statement of Work (SOW). As part of the Northwest Power Planning Council's Columbia Basin Fish and Wildlife Program (FWP), this project is one of Bonneville Power Administration's (BPA) many efforts at off-site mitigation for damage to salmon and steelhead runs, their migration, and wildlife habitat caused by the construction and operation of federal hydroelectric dams on the Columbia River and its tributaries. The proposed restoration activities within the Big Canyon Creek watershed follow the watershed restoration approach mandated by the Fisheries and Watershed Program. Nez Perce Tribal Fisheries/Watershed Program vision focuses on protecting, restoring, and enhancing watersheds and treaty resources within the ceded territory of the Nez Perce Tribe under the Treaty of 1855 with the United States Federal Government. The program uses a holistic approach, which encompasses entire watersheds, ridge top to ridge top, emphasizing all cultural aspects. We strive toward maximizing historic ecosystem productive health, for the restoration of anadromous and resident fish populations. The Nez Perce Tribal Fisheries/Watershed Program (NPTFWP) sponsors the Protect and Restore the Big Canyon Creek Watershed project. The NPTFWP has the authority to allocate funds under the provisions set forth in their contract with BPA. In the state of Idaho vast numbers of relatively small obstructions, such as road culverts, block thousands of miles of habitat suitable for a variety of fish species. To date, most agencies and land managers have not had sufficient, quantifiable data to adequately address these barrier sites. The ultimate objective of this comprehensive inventory and assessment was to identify all barrier crossings within the watershed. The barriers were then prioritized according to the

Urban Stream Burial Increases Watershed-Scale Nitrate Export.

Directory of Open Access Journals (Sweden)

Jake J Beaulieu

Full Text Available Nitrogen (N uptake in streams is an important ecosystem service that reduces nutrient loading to downstream ecosystems. Here we synthesize studies that investigated the effects of urban stream burial on N-uptake in two metropolitan areas and use simulation modeling to scale our measurements to the broader watershed scale. We report that nitrate travels on average 18 times farther downstream in buried than in open streams before being removed from the water column, indicating that burial substantially reduces N uptake in streams. Simulation modeling suggests that as burial expands throughout a river network, N uptake rates increase in the remaining open reaches which somewhat offsets reduced N uptake in buried reaches. This is particularly true at low levels of stream burial. At higher levels of stream burial, however, open reaches become rare and cumulative N uptake across all open reaches in the watershed rapidly declines. As a result, watershed-scale N export increases slowly at low levels of stream burial, after which increases in export become more pronounced. Stream burial in the lower, more urbanized portions of the watershed had a greater effect on N export than an equivalent amount of stream burial in the upper watershed. We suggest that stream daylighting (i.e., uncovering buried streams can increase watershed-scale N retention.

Watershed Planning within a Quantitative Scenario Analysis Framework.

Science.gov (United States)

Merriam, Eric R; Petty, J Todd; Strager, Michael P

2016-07-24

There is a critical need for tools and methodologies capable of managing aquatic systems within heavily impacted watersheds. Current efforts often fall short as a result of an inability to quantify and predict complex cumulative effects of current and future land use scenarios at relevant spatial scales. The goal of this manuscript is to provide methods for conducting a targeted watershed assessment that enables resource managers to produce landscape-based cumulative effects models for use within a scenario analysis management framework. Sites are first selected for inclusion within the watershed assessment by identifying sites that fall along independent gradients and combinations of known stressors. Field and laboratory techniques are then used to obtain data on the physical, chemical, and biological effects of multiple land use activities. Multiple linear regression analysis is then used to produce landscape-based cumulative effects models for predicting aquatic conditions. Lastly, methods for incorporating cumulative effects models within a scenario analysis framework for guiding management and regulatory decisions (e.g., permitting and mitigation) within actively developing watersheds are discussed and demonstrated for 2 sub-watersheds within the mountaintop mining region of central Appalachia. The watershed assessment and management approach provided herein enables resource managers to facilitate economic and development activity while protecting aquatic resources and producing opportunity for net ecological benefits through targeted remediation.

Mining Input Data for Multivariate Probabilistic Modeling of Rainfall-Induced Landslide Hazard in the Lake ATITLÁN Watershed in Guatemala

Science.gov (United States)

Cobin, P. F.; Oommen, T.; Gierke, J. S.

2013-12-01

The Lake Atitlán watershed is home to approximately 200,000 people and is located in the western highlands of Guatemala. Steep slopes, highly susceptible to landslides during the rainy season, characterize the region. Typically these landslides occur during high-intensity precipitation events. Hurricane Stan hit Guatemala in October 2005; the resulting flooding and landslides devastated the region. Locations of landslide and non-landslide points were obtained from field observations and orthophotos taken following Hurricane Stan. Different datasets of landslide and non-landslide points across the watershed were used to compare model success at a small scale and regional scale. This study used data from multiple attributes: geology, geomorphology, distance to faults and streams, land use, slope, aspect, curvature, plan curvature, profile curvature and topographic wetness index. The open source software Weka was used for the data mining. Several attribute selection methods were applied to the data to predetermine the potential landslide causative influence. Different multivariate algorithms were then evaluated for their ability to predict landslide occurrence. The following statistical parameters were used to evaluate model accuracy: precision, recall, F measure and area under the receiver operating characteristic (ROC) curve. The attribute combinations of the most successful models were compared to the attribute evaluator results. The algorithm BayesNet yielded the most accurate model and was used to build a probability map of landslide initiation points for the regions selected in the watershed. The ultimate aim of this study is to share the methodology and results with municipal contacts from the author's time as a U.S. Peace Corps volunteer, to facilitate more effective future landslide hazard planning and mitigation.

Study on origin and sedimentary environment of marine sediments from Kii Channel, Hiroshima Bay and Tosa Bay

International Nuclear Information System (INIS)

Suzuki, Misaki

2008-01-01

The trace amounts of elements in the sediments of sea bottom in Kii Channel, Hiroshima Bay and Tosa Bay were determined quantitatively by the neutron activation analysis. The following facts were illustrated particularly from the quantitative analysis of scandium, rare earths, thorium and uranium: 1) It was known from Ce/La ratio that the geological feature in the west part of Japan is reflected in Kii Channel, Hiroshima Bay and Tosa Bay; 2) The rare-earth element pattern and La/Lu ratio suggest the fact that Kii Channel, Hiroshima Bay and Tosa Bay are essentially composed of the materials of which origin is land; 3) From the fact that Ce/La ratio in these sites are slightly under 1.0, these sites are considered to be affected mainly by the materials of which origin is land; 4) The sedimentary environment in the marine bottom of the Japanese coasts has been found to be mostly under a reductive state. (M.H.)

A systematic assessment of watershed-scale nonpoint source pollution during rainfall-runoff events in the Miyun Reservoir watershed.

Science.gov (United States)

Qiu, Jiali; Shen, Zhenyao; Wei, Guoyuan; Wang, Guobo; Xie, Hui; Lv, Guanping

2018-03-01

The assessment of peak flow rate, total runoff volume, and pollutant loads during rainfall process are very important for the watershed management and the ecological restoration of aquatic environment. Real-time measurements of rainfall-runoff and pollutant loads are always the most reliable approach but are difficult to carry out at all desired location in the watersheds considering the large consumption of material and financial resources. An integrated environmental modeling approach for the estimation of flash streamflow that combines the various hydrological and quality processes during rainstorms within the agricultural watersheds is essential to develop targeted management strategies for the endangered drinking water. This study applied the Hydrological Simulation Program-Fortran (HSPF) to simulate the spatial and temporal variation in hydrological processes and pollutant transport processes during rainstorm events in the Miyun Reservoir watershed, a drinking water resource area in Beijing. The model performance indicators ensured the acceptable applicability of the HSPF model to simulate flow and pollutant loads in the studied watershed and to establish a relationship between land use and the parameter values. The proportion of soil and land use was then identified as the influencing factors of the pollution intensities. The results indicated that the flush concentrations were much higher than those observed during normal flow periods and considerably exceeded the limits of Class III Environmental Quality Standards for Surface Water (GB3838-2002) for the secondary protection zones of the drinking water resource in China. Agricultural land and leached cinnamon soils were identified as the key sources of sediment, nutrients, and fecal coliforms. Precipitation volume was identified as a driving factor that determined the amount of runoff and pollutant loads during rainfall processes. These results are useful to improve the streamflow predictions, provide

76 FR 28309 - Drawbridge Operation Regulation; Sturgeon Bay Ship Canal, Sturgeon Bay, WI

Science.gov (United States)

2011-05-17

... vehicular traffic congestion would not develop on downtown Sturgeon Bay streets due to unscheduled bridge... schedules during the peak tourist and navigation seasons to provide for the efficient movement of vehicular... between Lake Michigan and Green Bay. The area experiences a significant increase in vehicular and vessel...

Watershed Conservation in the Long Run

DEFF Research Database (Denmark)

Kaiser, Brooks

2014-01-01

We studied unanticipated long-run outcomes of conservation activities that occurred in forested watersheds on O`ahu, Hawaii, in the early twentieth century. The initial general impetus for the conservation activities was to improve irrigation surface water flow for the sugar industry. Industry...... concentration facilitated conservation of entire ecosystems. We investigate the benefits that accrued through dynamic linkages of the hydrological cycle and groundwater aquifer system. This provides a clear example of the need to consider integrated watershed effects, industrial structure, and linkages...... in determining conservation policy. We incorporated remote-sensing data, expert opinion on current watershed quality, and a spatial economic and hydrological model of O`ahu’s freshwater use with reports of conservation activities from 1910–1960 to assess these benefits. We find a 2.3% annual increase...

Watershed responses to Amazon soya bean cropland expansion and intensification.

Science.gov (United States)

Neill, Christopher; Coe, Michael T; Riskin, Shelby H; Krusche, Alex V; Elsenbeer, Helmut; Macedo, Marcia N; McHorney, Richard; Lefebvre, Paul; Davidson, Eric A; Scheffler, Raphael; Figueira, Adelaine Michela e Silva; Porder, Stephen; Deegan, Linda A

2013-06-05

The expansion and intensification of soya bean agriculture in southeastern Amazonia can alter watershed hydrology and biogeochemistry by changing the land cover, water balance and nutrient inputs. Several new insights on the responses of watershed hydrology and biogeochemistry to deforestation in Mato Grosso have emerged from recent intensive field campaigns in this region. Because of reduced evapotranspiration, total water export increases threefold to fourfold in soya bean watersheds compared with forest. However, the deep and highly permeable soils on the broad plateaus on which much of the soya bean cultivation has expanded buffer small soya bean watersheds against increased stormflows. Concentrations of nitrate and phosphate do not differ between forest or soya bean watersheds because fixation of phosphorus fertilizer by iron and aluminium oxides and anion exchange of nitrate in deep soils restrict nutrient movement. Despite resistance to biogeochemical change, streams in soya bean watersheds have higher temperatures caused by impoundments and reduction of bordering riparian forest. In larger rivers, increased water flow, current velocities and sediment flux following deforestation can reshape stream morphology, suggesting that cumulative impacts of deforestation in small watersheds will occur at larger scales.

Watershed Landscape Ecology: Interdisciplinary and Field-based Learning in the Northeast Creek Watershed, Mount Desert Island, Maine

Science.gov (United States)

Hall, S. R.; Anderson, J.; Rajakaruna, N.; Cass, D.

2014-12-01

At the College of the Atlantic, Bar Harbor, Maine, undergraduate students have the opportunity to design their own curriculum within a major of "Human Ecology." To enable students to have early research experiences, we developed a field-based interdisciplinary program for students to learn and practice field methods in a variety of disciplines, Earth Science, Botany, Chemistry, and Wildlife Biology at three specific field sites within a single watershed on Mt. Desert Island. As the Northeast Creek watershed was the site of previous water quality studies, this program of courses enabled continued monitoring of portions of the watershed. The program includes 4 new courses: Critical Zone 1, Critical Zone 2, Wildlife Biology, and Botany. In Critical Zone 1 students are introduced to general topics in Earth Science and learn to use ArcGIS to make basic maps. In Critical Zone 2, Wildlife Biology, and Botany, students are in the field every week using classic field tools and methods. All three of these courses use the same three general field areas: two with working farms at the middle and lower portion of the watershed and one uninhabited forested property in the higher relief headwaters of the watershed. Students collect daily surface water chemistry data at five stream sites within the watershed, complete basic geologic bedrock and geomorphic mapping, conduct wildlife surveys, botanical surveys, and monitor weather patterns at each of the main sites. Beyond the class data collected and synthesized, students also complete group independent study projects at focused field sites, some of which have turned into much larger research projects. This program is an opportunity for students and faculty with varied interests and expertise to work together to study a specific field locality over multiple years. We see this model as enhancing a number of positive education components: field-based learning, teamwork, problem solving, interdisciplinary discussion, multiple faculty

76 FR 22809 - Safety Zone; Bay Ferry II Maritime Security Exercise; San Francisco Bay, San Francisco, CA

Science.gov (United States)

2011-04-25

... DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Part 165 [Docket No. USCG-2011-0196] RIN 1625-AA00 Safety Zone; Bay Ferry II Maritime Security Exercise; San Francisco Bay, San Francisco, CA AGENCY... Security Exercise; San Francisco Bay, San Francisco, CA. (a) Location. The limits of this safety zone...

Lithogenic sources, composition and intra-annual variability of suspended particulate matter supplied from rivers to the Northern Galician Rias (Bay of Biscay)

Science.gov (United States)

Bernárdez, Patricia; Prego, Ricardo; Filgueiras, Ana Virginia; Ospina-Álvarez, Natalia; Santos-Echeandía, Juan; Álvarez-Vázquez, Miguel Angel; Caetano, Miguel

2017-12-01

Scarce research about small European rivers from non-human impacted areas to determine their natural background state has been undertaken. During the annual hydrological cycle of 2008-9 the patterns of particulate supply (SPM, POC, PON, Al, Cd, Co, Cr, Cu, Fe, Ni, Pb, V, Zn) from the rivers Sor, Mera Landro, Lourido and Landoi to the Northern Galician Rias (SW Bay of Biscay) were tackled. No differences in the composition of the SPM were detected for the studied rivers regarding Al, Fe and POC but the relative percentage of particulate trace elements (PTE) discriminate the rivers. So, Cr, Co and Ni in the Lourido, and Landoi rivers, and Cu in the Mera River, are controlled by watershed minerals of Ortegal Geological Complex while for the rest rivers PTE are by granitic and Ollo de Sapo bedrock watershed. Therefore, the imprint of PTE in the parental rocks of the river basins is reflected on the coastal sediments of the Rias. The main process controlling the dynamics and variations of chemical elements in the particulate form is the river discharge. This fact exemplifies that these rivers presents a natural behavior not being highly influenced by anthropogenic activities.

Responses of upland herpetofauna to the restoration of Carolina Bays and thinning of forested Bay Margins.

Energy Technology Data Exchange (ETDEWEB)

Ledvina, Joseph A.

2008-05-01

Research on the effects of wetland restoration on reptiles and amphibians is becoming more common, but almost all of these studies have observed the colonization of recently disturbed habitats that were completely dry at the time of restoration. In a similar manner, investigations herpetofaunal responses to forest management have focused on clearcuts, and less intensive stand manipulations are not as well studied. To evaluate community and population responses of reptiles and amphibians to hydrology restoration and canopy removal in the interior of previously degraded Carolina bays, I monitored herpetofauna in the uplands adjacent to six historically degraded Carolina bays at the Savannah River Site (SRS) in South Carolina for four years after restoration. To evaluate the effects of forest thinning on upland herpetofauna, forests were thinned in the margins of three of these bays. I used repeated measures ANOVA to compare species richness and diversity and the abundance of selected species and guilds between these bays and with those at three reference bays that were not historically drained and three control bays that remained degraded. I also used Non-metric Multidimensional Scaling (NMDS) to look for community-level patterns based treatments.

Kootenai River Focus Watershed Coordination, 2002-2003 Annual Report.

Energy Technology Data Exchange (ETDEWEB)

Munson, Bob; Munson, Vicki (Kootenai River Network, Libby, MT); Rogers, Rox (US Fish and Wildlife Service, Libby, MT)

2003-10-01

The Kootenai River Network Inc. (KRN) was incorporated in Montana in early 1995 with a mission ''to involve stakeholders in the protection and restoration of the chemical, physical and biological integrity of the Kootenai River Basin waters''. The KRN operates with funding from donations, membership dues, private, state and federal grants, and with funding through the Bonneville Power Administration (BPA) for a Focus Watershed Coordinator Program. The Focus Watershed Program is administered to KRN as of October 2001, through a Memorandum of Understanding. Katie Randall resigned her position as Watershed Coordinator in late January 2003 and Munson Consulting was contracted to fill that position through the BPA contract period ending May 30, 2003. To improve communications with in the Kootenai River watershed, the board and staff engaged watershed stakeholders in a full day KRN watershed conference on May 15 and 16 in Bonners Ferry, Idaho. This Annual General Meeting was a tremendous success with over 75 participants representing over 40 citizen groups, tribes and state/provincial/federal agencies from throughout northern Montana and Idaho as well as British Columbia and Alberta. Membership in the KRN increased during the course of the BPA 02/03 grant period. The board of directors grew in numbers during this same time frame and an Advisory Council was formed to assist in transboundary efforts while developing two reorganized KRN committees (Habitat/Restoration/Monitoring (HRM) and Communication/Education/Outreach (CEO)). These committees will serve pivotal roles in communications, outreach, and education about watershed issues, as well as habitat restoration work being accomplished throughout the entire watershed. During this BPA grant period, the KRN has capitalized on the transboundary interest in the Kootenai River watershed. Jim and Laura Duncan of Kimberley, British Columbia, have been instrumental volunteers who have acted as Canadian

When Everything Changes: Mountaintop Mining Effects on Watershed Hydrology

Science.gov (United States)

Nippgen, F.; Ross, M. R.; McGlynn, B. L.; Bernhardt, E. S.

2015-12-01

Mountaintop removal coal mining (MTM) in the Central Appalachians has expanded over the last 40 years to cover ~7% of this mountainous landscape. MTM operations remove mountaintops and ridges with explosives and machinery to access underlying coal seams. Much of this crushed rock overburden is subsequently deposited into nearby valleys, creating valley fills that often bury headwater streams. In contrast to other disturbances such as forest clear-cutting, perturbations from MTM can extend hundreds of meters deep into the critical zone and completely reshape landscapes. Despite the expansiveness and intensity of the disturbance, MTM has only recently begun to receive focused attention from the hydrologic community and the effect of MTM on the hydrology of impacted watersheds is still not well understood. We are using a two-pronged approach consisting of GIS analysis to quantify spoil volumes and landscape change, together with empirical analysis and modeling of rainfall and runoff data collected in two sets of paired watersheds. We seek to investigate how MTM affects basic hydrologic metrics, including storm peakflows, runoff response times, baseflow, statistics of flow duration curves, and longer-term water balances. Each pair consists of a mined and an unmined watershed; the first set contains headwater streams (size ~100ha), the second set consists of 3rd order streams, draining ~3500ha. Mining covers ~ 95% of the headwater watershed, and 40% of the 3rd-order watershed. Initial GIS analysis indicates that the overburden moved during the mining process could be up to three times greater than previously estimated. Storm runoff peaks in the mined watersheds were muted as compared to the unmined watersheds and runoff ratios were reduced by up to 75% during both wet and dry antecedent conditions. The natural reference watersheds were highly responsive while the additional storage in the mined watersheds led to decreased peak flows during storms and enhanced baseflow

McKenzie River focus watershed coordination: year-end report, 2001; ANNUAL

International Nuclear Information System (INIS)

Thrailkil, Jim

2001-01-01

BPA funding, in conjunction with contributions from numerous partners organizations, supports the McKenzie Watershed Council's efforts to coordinate restoration and monitoring programs of federal, state, local government, and residents within the watershed. The goal of the MWC is to improve resource stewardship and conserve fish, wildlife, and water quality resources. The MWC will always have a baseline program centered on relationship building and information sharing. Objectives for FY01 included: (1) Continue to coordinate McKenzie Watershed activities among diverse groups that restore fish and wildlife habitat in the watershed, with a focus on the lower McKenzie, including private lands and the McKenzie-Willamette confluence area; (2) Influence behavior of watershed residents to benefit watershed function though a strategic and comprehensive outreach and education program, utilizing Assessment and Conservation Strategy information to provide a context for prioritized action; (3) Continue to maintain and sustain a highly functional watershed council; (4) Maintain and improve water quality concerns through the continuation of Council-sponsored monitoring and evaluation programs; and (5) Continue to secure other funding for watershed restoration and protection projects and Council operations

A Bayes linear Bayes method for estimation of correlated event rates.

Science.gov (United States)

Quigley, John; Wilson, Kevin J; Walls, Lesley; Bedford, Tim

2013-12-01

Typically, full Bayesian estimation of correlated event rates can be computationally challenging since estimators are intractable. When estimation of event rates represents one activity within a larger modeling process, there is an incentive to develop more efficient inference than provided by a full Bayesian model. We develop a new subjective inference method for correlated event rates based on a Bayes linear Bayes model under the assumption that events are generated from a homogeneous Poisson process. To reduce the elicitation burden we introduce homogenization factors to the model and, as an alternative to a subjective prior, an empirical method using the method of moments is developed. Inference under the new method is compared against estimates obtained under a full Bayesian model, which takes a multivariate gamma prior, where the predictive and posterior distributions are derived in terms of well-known functions. The mathematical properties of both models are presented. A simulation study shows that the Bayes linear Bayes inference method and the full Bayesian model provide equally reliable estimates. An illustrative example, motivated by a problem of estimating correlated event rates across different users in a simple supply chain, shows how ignoring the correlation leads to biased estimation of event rates. © 2013 Society for Risk Analysis.

Exploring the nutrient inputs and cycles in Tampa Bay and coastal watersheds using MODIS images and data mining

Science.gov (United States)

Chang, Ni-Bin; Xuan, Zhemin

2011-09-01

Excessive nutrients, which may be represented as Total Nitrogen (TN) and Total Phosphorus (TP) levels, in natural water systems have proven to cause high levels of algae production. The process of phytoplankton growth which consumes the excess TN and TP in a water body can also be related to the changing water quality levels, such as Dissolved Oxygen (DO), chlorophyll-a, and turbidity, associated with their changes in absorbance of natural radiation. This paper explores spatiotemporal nutrient patterns in Tampa Bay, Florida with the aid of Moderate Resolution Imaging Spectroradiometer or MODIS images and Genetic Programming (GP) models that are deigned to link those relevant water quality parameters in aquatic environments.

A GIS-based disaggregate spatial watershed analysis using RADAR data

International Nuclear Information System (INIS)

Al-Hamdan, M.

2002-01-01

Hydrology is the study of water in all its forms, origins, and destinations on the earth.This paper develops a novel modeling technique using a geographic information system (GIS) to facilitate watershed hydrological routing using RADAR data. The RADAR rainfall data, segmented to 4 km by 4 km blocks, divides the watershed into several sub basins which are modeled independently. A case study for the GIS-based disaggregate spatial watershed analysis using RADAR data is provided for South Fork Cowikee Creek near Batesville, Alabama. All the data necessary to complete the analysis is maintained in the ArcView GIS software. This paper concludes that the GIS-Based disaggregate spatial watershed analysis using RADAR data is a viable method to calculate hydrological routing for large watersheds. (author)

Phosphorus losses from an irrigated watershed in the Northwestern U.S.: Case study of the Upper Snake Rock Watershed

Science.gov (United States)

Watersheds utilizing surface water for irrigation often return a portion of the water to a water body. This irrigation return flow often includes sediment and nutrients that reduce the quality of the receiving water body. Research in the 82,000 ha Upper Snake Rock (USR) watershed from 2005 to 2008 s...

Florida Bay: A history of recent ecological changes

Science.gov (United States)

Fourqurean, J.W.; Robblee, M.B.

1999-01-01

Florida Bay is a unique subtropical estuary at the southern tip of the Florida peninsula. Recent ecological changes (seagrass die-off, algal blooms, increased turbidity) to the Florida Bay ecosystem have focused the attention of the public, commercial interests, scientists, and resource managers on the factors influencing the structure and function of Florida Bay. Restoring Florida Bay to some historic condition is the goal of resource managers, but what is not clear is what an anthropogenically-unaltered Florida Bay would look like. While there is general consensus that human activities have contributed to the changes occurring in the Florida Bay ecosystem, a high degree of natural system variability has made elucidation of the links between human activity and Florida Bay dynamics difficult. Paleoecological analyses, examination of long-term datasets, and directed measurements of aspects of the ecology of Florida Bay all contribute to our understanding of the behavior of the bay, and allow quantification of the magnitude of the recent ecological changes with respect to historical variability of the system.

Managing Watersheds as Couple Human-Natural Systems: A Review of Research Opportunities

Science.gov (United States)

Cai, X.

2011-12-01

Many watersheds around the world are impaired with severe social and environmental problems due to heavy anthropogenic stresses. Humans have transformed hydrological and biochemical processes in watersheds from a stationary to non-stationary status through direct (e.g., water withdrawals) and indirect (e.g., altering vegetation and land cover) interferences. It has been found that in many watersheds that socio-economic drivers, which have caused increasingly intensive alteration of natural processes, have even overcome natural variability to become the dominant factor affecting the behavior of watershed systems. Reversing this trend requires an understanding of the drivers of this intensification trajectory, and needs tremendous policy reform and investment. As stressed by several recent National Research Council (NRC) reports, watershed management will pose an enormous challenge in the coming decades. Correspondingly, the focus of research has started an evolution from the management of reservoir, stormwater and aquifer systems to the management of integrated watershed systems, to which policy instruments designed to make more rational economic use of water resources are likely to be applied. To provide a few examples: reservoir operation studies have moved from a local to a watershed scale in order to consider upstream best management practices in soil conservation and erosion control and downstream ecological flow requirements and water rights; watersheds have been modeled as integrated hydrologic-economic systems with multidisciplinary modeling efforts, instead of traditional isolated physical systems. Today's watershed management calls for a re-definition of watersheds from isolated natural systems to coupled human-natural systems (CHNS), which are characterized by the interactions between human activities and natural processes, crossing various spatial and temporal scales within the context of a watershed. The importance of the conceptual innovation has been

URBAN WATERSHED STUDIES IN SOUTHERN BRAZIL

Directory of Open Access Journals (Sweden)

Cristiano Poleto

2007-01-01

Full Text Available One of the greatest problems observed in Brazilian urban watersheds are concerned to the amount of solid residues, domestic sewerage and sediments that are disposed in the rivers and streams that drain those areas. This project aims to present these problems through a study of case taken in an urban watershed in Porto Alegre city, Southern Brazil. For this study, different procedures were used, such as field surveys, interviews with the inhabitants, satellite images, sediment samples, flow measures and morphology assessment of part of the local fluvial system to check the degree of instability of the channel. In 2005, it was verified that 42.57% of the watershed was impermeable, considering the paved streets, the residential and commercial buildings and stone pavements. As there was no sewer treatment, most of this sewerage was directly disposed into the stream and the TOC has reached 20% (m/m. Moreover, the occupation of riparian areas, a great amount of soil exposed in the watershed, the nonpaved streets and a great volume of solid residues were causing the instability in the channel, silting the stream bed. The metals (Zn, Pb and Cr selected for this study are most frequently found in high concentrations in urban areas. The results suggest the occurrence of a high enrichment of the fluvial sediment by these metals. The concentrations of these elements vary temporally during storms due to the input of impervious area runoff containing high concentration of elements associated to vehicular traffic and other anthropogenic activities. Then, it is possible to conclude that the contamination of the urban watershed is reflected in the results obtained in the fluvial suspended sediments.

URBAN WATERSHED STUDIES IN SOUTHERN BRAZIL

Directory of Open Access Journals (Sweden)

Cristiano Poleto

2007-12-01

Full Text Available One of the greatest problems observed in Brazilian urban watersheds are concerned to the amount of solid residues, domestic sewerage and sediments that are disposed in the rivers and streams that drain those areas. This project aims to present these problems through a study of case taken in an urban watershed in Porto Alegre city, Southern Brazil. For this study, different procedures were used, such as field surveys, interviews with the inhabitants, satellite images, sediment samples, flow measures and morphology assessment of part of the local fluvial system to check the degree of instability of the channel. In 2005, it was verified that 42.57% of the watershed was impermeable, considering the paved streets, the residential and commercial buildings and stone pavements. As there was no sewer treatment, most of this sewerage was directly disposed into the stream and the TOC has reached 20% (m/m. Moreover, the occupation of riparian areas, a great amount of soil exposed in the watershed, the nonpaved streets and a great volume of solid residues were causing the instability in the channel, silting the stream bed. The metals (Zn, Pb and Cr selected for this study are most frequently found in high concentrations in urban areas. The results suggest the occurrence of a high enrichment of the fluvial sediment by these metals. The concentrations of these elements vary temporally during storms due to the input of impervious area runoff containing high concentration of elements associated to vehicular traffic and other anthropogenic activities. Then, it is possible to conclude that the contamination of the urban watershed is reflected in the results obtained in the fluvial suspended sediments.

Guiding principles for management of forested, agricultural, and urban watersheds

Science.gov (United States)

Pamela J. Edwards; Jon E. Schoonover; Karl W.J. Williard

2015-01-01

Human actions must be well planned and include consideration of their potential influences on water and aquatic ecosystems - such consideration is the foundation of watershed management. Watersheds are the ideal land unit for managing and protecting water resources and aquatic health because watersheds integrate the physical, biological and chemical processes within...

Assessing the impacts of future climate conditions on the effectiveness of winter cover crops in reducing nitrate loads into the Chesapeake Bay Watershed using SWAT model

Science.gov (United States)

Lee, Sangchul; Sadeghi, Ali M.; Yeo, In-Young; McCarty, Gregory W.; Hively, W. Dean

2017-01-01

Winter cover crops (WCCs) have been widely implemented in the Coastal Plain of the Chesapeake Bay watershed (CBW) due to their high effectiveness at reducing nitrate loads. However, future climate conditions (FCCs) are expected to exacerbate water quality degradation in the CBW by increasing nitrate loads from agriculture. Accordingly, the question remains whether WCCs are sufficient to mitigate increased nutrient loads caused by FCCs. In this study, we assessed the impacts of FCCs on WCC nitrate reduction efficiency on the Coastal Plain of the CBW using Soil and Water Assessment Tool (SWAT) model. Three FCC scenarios (2085 – 2098) were prepared using General Circulation Models (GCMs), considering three Intergovernmnental Panel on Climate Change (IPCC) Special Report on Emissions Scenarios (SRES) greenhouse gas emission scenarios. We also developed six representative WCC implementation scenarios based on the most commonly used planting dates and species of WCCs in this region. Simulation results showed that WCC biomass increased by ~ 58 % under FCC scenarios, due to climate conditions conducive to the WCC growth. Prior to implementing WCCs, annual nitrate loads increased by ~ 43 % under FCC scenarios compared to the baseline scenario (2001 – 2014). When WCCs were planted, annual nitrate loads were substantially reduced by ~ 48 % and WCC nitrate reduction efficiency water ~ 5 % higher under FCC scenarios relative to the baseline. The increase rate of WCC nitrate reduction efficiency varied by FCC scenarios and WCC planting methods. As CO2 concentration was higher and winters were warmer under FCC scenarios, WCCs had greater biomass and therefore showed higher nitrate reduction efficiency. In response to FCC scenarios, the performance of less effective WCC practices (e.g., barley, wheat, and late planting) under the baseline indicated ~ 14 % higher increase rate of nitrate reduction efficiency compared to ones with better effectiveness under the baseline (e

Bird surveys at McKinley Bay and Hutchinson Bay, Northwest Territories, in 1990

Energy Technology Data Exchange (ETDEWEB)

Cornish, B J; Dickson, D L; Dickson, H L

1991-03-01

Monitoring surveys of bird abundance and distribution were conducted in 1990 at McKinley Bay in the Northwest Territories, the site of a winter harbour for drillships and the proposed location for a major year-round support base for oil and gas exploration. Primary objectives of the survey were to determine whether diving duck numbers had changed since the initial phase of the study from 1981-1985, and to provide additional baseline data on natural annual fluctuations in diving duck numbers. Three aerial surveys at each bay were carried out using techniques identical to those in previous years. On 5 August 1990, when survey conditions were considered best of the three surveys, more than twice as many diving ducks were found in McKinley Bay and Hutchinson Bay than on average during the five years of 1981-1985. Old squaw and scooters comprised ca 90% of the diving ducks observed, and both species showed significant increases in numbers. The increase in abundance of diving ducks was likely unrelated to industrial activity in the area since a similar increase occurred in the control area, Hutchinson Bay. Many factors, including both environmental factors such as those affecting nesting success and timing of the moult, and factors related to the survey methods, could be involved in causing the large fluctuations observed. 9 refs., 8 figs., 10 tabs.

Bird surveys at McKinley Bay and Hutchinson Bay, Northwest Territories, in 1990

International Nuclear Information System (INIS)

Cornish, B.J.; Dickson, D.L.; Dickson, H.L.

1991-01-01

Monitoring surveys of bird abundance and distribution were conducted in 1990 at McKinley Bay in the Northwest Territories, the site of a winter harbour for drillships and the proposed location for a major year-round support base for oil and gas exploration. Primary objectives of the survey were to determine whether diving duck numbers had changed since the initial phase of the study from 1981-1985, and to provide additional baseline data on natural annual fluctuations in diving duck numbers. Three aerial surveys at each bay were carried out using techniques identical to those in previous years. On 5 August 1990, when survey conditions were considered best of the three surveys, more than twice as many diving ducks were found in McKinley Bay and Hutchinson Bay than on average during the five years of 1981-1985. Old squaw and scooters comprised ca 90% of the diving ducks observed, and both species showed significant increases in numbers. The increase in abundance of diving ducks was likely unrelated to industrial activity in the area since a similar increase occurred in the control area, Hutchinson Bay. Many factors, including both environmental factors such as those affecting nesting success and timing of the moult, and factors related to the survey methods, could be involved in causing the large fluctuations observed. 9 refs., 8 figs., 10 tabs

Watershed-based Morphometric Analysis: A Review

Science.gov (United States)

Sukristiyanti, S.; Maria, R.; Lestiana, H.

2018-02-01

Drainage basin/watershed analysis based on morphometric parameters is very important for watershed planning. Morphometric analysis of watershed is the best method to identify the relationship of various aspects in the area. Despite many technical papers were dealt with in this area of study, there is no particular standard classification and implication of each parameter. It is very confusing to evaluate a value of every morphometric parameter. This paper deals with the meaning of values of the various morphometric parameters, with adequate contextual information. A critical review is presented on each classification, the range of values, and their implications. Besides classification and its impact, the authors also concern about the quality of input data, either in data preparation or scale/the detail level of mapping. This review paper hopefully can give a comprehensive explanation to assist the upcoming research dealing with morphometric analysis.

Linking ecosystem service supply to stakeholder concerns on ...

Science.gov (United States)

Policies to protect coastal resources may lead to greater social, economic, and ecological returns when they consider potential co-benefits and trade-offs on land. In Guánica Bay watershed, Puerto Rico, a watershed management plan is being implemented to restore declining quality of coral reefs due to sediment and nutrient runoff. However, recent stakeholder workshops indicated uncertainty about benefits for the local community. A total of 19 metrics were identified to capture stakeholder concerns, including 15 terrestrial ecosystem services in the watershed and 4 metrics in the coastal zone. Ecosystem service production functions were applied to quantify and map ecosystem service supply in 1) the Guánica Bay watershed and 2) a highly engineered upper multi-watershed area connected to the lower watershed via a series of reservoirs and tunnels. These two watersheds were compared to other watersheds in Puerto Rico. Relative to other watersheds, the Upper Guánica watershed had high air pollutant removal rates, forest habitat area, biodiversity of charismatic and endangered species, but low farmland quality and low sediment retention. The Lower Guánica watershed had high rates of denitrification and high levels of marine-based recreational and fishing opportunities compared to other watersheds, but moderate to low air pollutant removal, soil carbon content, sediment and nutrient retention, and terrestrial biodiversity. Our results suggest that actions in the wat

Climate change and watershed mercury export: a multiple projection and model analysis.

Science.gov (United States)

Golden, Heather E; Knightes, Christopher D; Conrads, Paul A; Feaster, Toby D; Davis, Gary M; Benedict, Stephen T; Bradley, Paul M

2013-09-01

Future shifts in climatic conditions may impact watershed mercury (Hg) dynamics and transport. An ensemble of watershed models was applied in the present study to simulate and evaluate the responses of hydrological and total Hg (THg) fluxes from the landscape to the watershed outlet and in-stream THg concentrations to contrasting climate change projections for a watershed in the southeastern coastal plain of the United States. Simulations were conducted under stationary atmospheric deposition and land cover conditions to explicitly evaluate the effect of projected precipitation and temperature on watershed Hg export (i.e., the flux of Hg at the watershed outlet). Based on downscaled inputs from 2 global circulation models that capture extremes of projected wet (Community Climate System Model, Ver 3 [CCSM3]) and dry (ECHAM4/HOPE-G [ECHO]) conditions for this region, watershed model simulation results suggest a decrease of approximately 19% in ensemble-averaged mean annual watershed THg fluxes using the ECHO climate-change model and an increase of approximately 5% in THg fluxes with the CCSM3 model. Ensemble-averaged mean annual ECHO in-stream THg concentrations increased 20%, while those of CCSM3 decreased by 9% between the baseline and projected simulation periods. Watershed model simulation results using both climate change models suggest that monthly watershed THg fluxes increase during the summer, when projected flow is higher than baseline conditions. The present study's multiple watershed model approach underscores the uncertainty associated with climate change response projections and their use in climate change management decisions. Thus, single-model predictions can be misleading, particularly in developmental stages of watershed Hg modeling. Copyright © 2013 SETAC.

Climate change and watershed mercury export: a multiple projection and model analysis

Science.gov (United States)

Golden, Heather E.; Knightes, Christopher D.; Conrads, Paul; Feaster, Toby D.; Davis, Gary M.; Benedict, Stephen T.; Bradley, Paul M.

2013-01-01

Future shifts in climatic conditions may impact watershed mercury (Hg) dynamics and transport. An ensemble of watershed models was applied in the present study to simulate and evaluate the responses of hydrological and total Hg (THg) fluxes from the landscape to the watershed outlet and in-stream THg concentrations to contrasting climate change projections for a watershed in the southeastern coastal plain of the United States. Simulations were conducted under stationary atmospheric deposition and land cover conditions to explicitly evaluate the effect of projected precipitation and temperature on watershed Hg export (i.e., the flux of Hg at the watershed outlet). Based on downscaled inputs from 2 global circulation models that capture extremes of projected wet (Community Climate System Model, Ver 3 [CCSM3]) and dry (ECHAM4/HOPE-G [ECHO]) conditions for this region, watershed model simulation results suggest a decrease of approximately 19% in ensemble-averaged mean annual watershed THg fluxes using the ECHO climate-change model and an increase of approximately 5% in THg fluxes with the CCSM3 model. Ensemble-averaged mean annual ECHO in-stream THg concentrations increased 20%, while those of CCSM3 decreased by 9% between the baseline and projected simulation periods. Watershed model simulation results using both climate change models suggest that monthly watershed THg fluxes increase during the summer, when projected flow is higher than baseline conditions. The present study's multiple watershed model approach underscores the uncertainty associated with climate change response projections and their use in climate change management decisions. Thus, single-model predictions can be misleading, particularly in developmental stages of watershed Hg modeling.

Runoff Potentiality of a Watershed through SCS and Functional Data Analysis Technique

Directory of Open Access Journals (Sweden)

M. I. Adham

2014-01-01

Full Text Available Runoff potentiality of a watershed was assessed based on identifying curve number (CN, soil conservation service (SCS, and functional data analysis (FDA techniques. Daily discrete rainfall data were collected from weather stations in the study area and analyzed through lowess method for smoothing curve. As runoff data represents a periodic pattern in each watershed, Fourier series was introduced to fit the smooth curve of eight watersheds. Seven terms of Fourier series were introduced for the watersheds 5 and 8, while 8 terms of Fourier series were used for the rest of the watersheds for the best fit of data. Bootstrapping smooth curve analysis reveals that watersheds 1, 2, 3, 6, 7, and 8 are with monthly mean runoffs of 29, 24, 22, 23, 26, and 27 mm, respectively, and these watersheds would likely contribute to surface runoff in the study area. The purpose of this study was to transform runoff data into a smooth curve for representing the surface runoff pattern and mean runoff of each watershed through statistical method. This study provides information of runoff potentiality of each watershed and also provides input data for hydrological modeling.

Runoff Potentiality of a Watershed through SCS and Functional Data Analysis Technique

Science.gov (United States)

Adham, M. I.; Shirazi, S. M.; Othman, F.; Rahman, S.; Yusop, Z.; Ismail, Z.

2014-01-01

Runoff potentiality of a watershed was assessed based on identifying curve number (CN), soil conservation service (SCS), and functional data analysis (FDA) techniques. Daily discrete rainfall data were collected from weather stations in the study area and analyzed through lowess method for smoothing curve. As runoff data represents a periodic pattern in each watershed, Fourier series was introduced to fit the smooth curve of eight watersheds. Seven terms of Fourier series were introduced for the watersheds 5 and 8, while 8 terms of Fourier series were used for the rest of the watersheds for the best fit of data. Bootstrapping smooth curve analysis reveals that watersheds 1, 2, 3, 6, 7, and 8 are with monthly mean runoffs of 29, 24, 22, 23, 26, and 27 mm, respectively, and these watersheds would likely contribute to surface runoff in the study area. The purpose of this study was to transform runoff data into a smooth curve for representing the surface runoff pattern and mean runoff of each watershed through statistical method. This study provides information of runoff potentiality of each watershed and also provides input data for hydrological modeling. PMID:25152911

78 FR 27126 - East Bay, St. Andrews Bay and the Gulf of Mexico at Tyndall Air Force Base, Florida; Restricted...

Science.gov (United States)

2013-05-09

... DEPARTMENT OF DEFENSE Department of the Army, Corps of Engineers 33 CFR Part 334 East Bay, St. Andrews Bay and the Gulf of Mexico at Tyndall Air Force Base, Florida; Restricted Areas AGENCY: U.S. Army... read as follows: Sec. 334.665 East Bay, St. Andrews Bay and the Gulf of Mexico, Restricted Areas...

Habitat Mapping and Classification of the Grand Bay National Estuarine Research Reserve using AISA Hyperspectral Imagery

Science.gov (United States)

Rose, K.

2012-12-01

Habitat mapping and classification provides essential information for land use planning and ecosystem research, monitoring and management. At the Grand Bay National Estuarine Research Reserve (GRDNERR), Mississippi, habitat characterization of the Grand Bay watershed will also be used to develop a decision-support tool for the NERR's managers and state and local partners. Grand Bay NERR habitat units were identified using a combination of remotely sensed imagery, aerial photography and elevation data. Airborne Imaging Spectrometer for Applications (AISA) hyperspectral data, acquired 5 and 6 May 2010, was analyzed and classified using ENVI v4.8 and v5.0 software. The AISA system was configured to return 63 bands of digital imagery data with a spectral range of 400 to 970 nm (VNIR), spectral resolution (bandwidth) at 8.76 nm, and 1 m spatial resolution. Minimum Noise Fraction (MNF) and Inverse Minimum Noise Fraction were applied to the data prior to using Spectral Angle Mapper ([SAM] supervised) and ISODATA (unsupervised) classification techniques. The resulting class image was exported to ArcGIS 10.0 and visually inspected and compared with the original imagery as well as auxiliary datasets to assist in the attribution of habitat characteristics to the spectral classes, including: National Agricultural Imagery Program (NAIP) aerial photography, Jackson County, MS, 2010; USFWS National Wetlands Inventory, 2007; an existing GRDNERR habitat map (2004), SAV (2009) and salt panne (2002-2003) GIS produced by GRDNERR; and USACE lidar topo-bathymetry, 2005. A field survey to validate the map's accuracy will take place during the 2012 summer season. ENVI's Random Sample generator was used to generate GIS points for a ground-truth survey. The broad range of coastal estuarine habitats and geomorphological features- many of which are transitional and vulnerable to environmental stressors- that have been identified within the GRDNERR point to the value of the Reserve for

INTEGRATED WATERSHED MANAGEMENT: PRINCIPLES AND PRACTICE. Book Review

Science.gov (United States)

Through a wide range of information and topics, Integrated Watershed Management Principles and Practice shows how involved the watershed management planning process can be. The book is informative, and the author obviously has researched the subject thoroughly. The book's case...

Spill management strategy for the Chesapeake Bay

International Nuclear Information System (INIS)

Butler, H.L.; Chapman, R.S.; Johnson, B.H.

1990-01-01

The Chesapeake Bay Program is a unique cooperative effort between state and Federal agencies to restore the health and productivity of America's largest estuary. To assist in addressing specific management issues, a comprehensive three-dimensional, time-varying hydrodynamic and water quality model has ben developed. The Bay modeling strategy will serve as an excellent framework for including submodules to predict the movement, dispersion, and weathering of accidental spills, such as for petroleum products or other chemicals. This paper presents sample results from the Bay application to illustrate the success of the model system in simulating Bay processes. Also, a review of model requirements for successful spill modeling in Chesapeake Bay is presented. Recommendations are given for implementing appropriate spill modules with the Bay model framework and establishing a strategy for model use in addressing management issues

Accountability to Public Stakeholders in Watershed-Based Restoration

Science.gov (United States)

There is an increasing push at the federal, state, and local levels for watershed-based conservation projects. These projects work to address water quality issues in degraded waterways through the implementation of a suite of best management practices on land throughout a watersh...

AN ARCGIS TOOL FOR CREATING POPULATIONS OF WATERSHEDS

Science.gov (United States)

For the Landscape Investigations for Pesticides Study in the Midwest, the goal is to sample a representative subset of watersheds selected statistically from a target population of watersheds within the glaciated corn belt. This area stretches from Ohio to Iowa and includes parts...

Laser altimeter measurements at Walnut Gulch Watershed, Arizona

International Nuclear Information System (INIS)

Ritchie, J.C.; Humes, K.S.; Weltz, M.A.

1995-01-01

Measurements of landscape surface roughness properties are necessary for understanding many watershed processes. This paper reviews the use of an airborne laser altimeter to measure topography and surface roughness properties of the landscape at Walnut Gulch Watershed in Arizona. Airborne laser data were used to measure macro and micro topography as well as canopy topography, height, cover, and distribution. Macro topography of landscape profiles for segments up to 5 km (3 mi) were measured and were in agreement with available topographic maps but provided more detail. Gullies and stream channel cross-sections and their associated floodplains were measured. Laser measurements of vegetation properties (height and cover) were highly correlated with ground measurements. Landscape segments for any length can be used to measure these landscape roughness properties. Airborne laser altimeter measurements of landscape profiles can provide detailed information on watershed surface properties for improving the management of watersheds. (author)

The Impossible Sustainability of the Bay of Brest? Fifty Years of Ecosystem Changes, Interdisciplinary Knowledge Construction and Key Questions at the Science-Policy-Community Interface

Directory of Open Access Journals (Sweden)

Olivier Ragueneau

2018-04-01

Full Text Available In this contribution, the study of the Bay of Brest ecosystem changes over the past 50 years is used to explore the construction of interdisciplinary knowledge and raise key questions that now need to be tackled at the science-policy-communities interface. The Bay of Brest is subject to a combination of several aspects of global change, including excessive nutrient inputs from watersheds and the proliferation of invasive species. These perturbations strongly interact, affecting positively or negatively the ecosystem functioning, with important impacts on human activities. We first relate a cascade of events over these five decades, linking farming activities, nitrogen, and silicon biogeochemical cycles, hydrodynamics of the Bay, the proliferation of an exotic benthic suspension feeder, the development of the Great scallop fisheries and the high biodiversity in maerl beds. The cascade leads to today's situation where toxic phytoplankton blooms become recurrent in the Bay, preventing the fishery of the great scallop and forcing the fishermen community to switch pray and alter the maerl habitat and the benthic biodiversity it hosts, despite the many scientific alerts and the protection of this habitat. In the second section, we relate the construction of the interdisciplinary knowledge without which scientists would never have been able to describe these changes in the Bay. Interdisciplinarity construction is described, first among natural sciences (NS and then, between natural sciences and human and social sciences (HSS. We finally ask key questions at the science-policy interface regarding this unsustainable trend of the Bay: How is this possible, despite decades of joint work between scientists and fishermen? Is adaptive co-management a sufficient condition for a sustainable management of an ecosystem? How do the different groups (i.e., farmers, fishermen, scientists, environmentalists, with their diverse interests, take charge of this situation

Chesapeake Bay plume dynamics from LANDSAT

Science.gov (United States)

Munday, J. C., Jr.; Fedosh, M. S.

1981-01-01

LANDSAT images with enhancement and density slicing show that the Chesapeake Bay plume usually frequents the Virginia coast south of the Bay mouth. Southwestern (compared to northern) winds spread the plume easterly over a large area. Ebb tide images (compared to flood tide images) show a more dispersed plume. Flooding waters produce high turbidity levels over the shallow northern portion of the Bay mouth.

The US Forest Service Watershed Condition Classification: Status and Path Forward

Science.gov (United States)

Levinson, D. H.; Carlson, C. P.; Eberle, M. B.

2017-12-01

The US Forest Service Watershed Condition Classification (WCC) was developed as a tool to characterize the condition or health of watersheds on National Forests and Grasslands and assist the Agency in prioritizing actions to restore or maintain the condition of specified watersheds. After a number of years of exploring alternative approaches to assessing the health or condition of watersheds, the WCC and the associated Watershed Condition Framework were developed in response to concerns raised by the US Office of Management and Budget that the Forest Service was not able to demonstrate success in restoring watersheds on a national scale. The WCC was initially applied in 2011 to the roughly 15,000 HUC12 watersheds with an area of Forest Service management of 5% or greater. This initial watershed classification found that 52% (or 7,882) were Functioning Properly (Class 1), 45% (or 6,751) were Functioning at Risk (Class 2), and 3% (or 431) had Impaired Function (Class 3). The basic model used in the WCC was intended to provide a reconnaissance-level evaluation of watershed condition through the use of a systematic, flexible means of classifying and comparing watersheds based on a core set of national watershed condition indicators. The WCC consists of 12 indicators in four major process categories: (1) aquatic physical, (2) aquatic biological, (3) terrestrial physical, and (4) terrestrial biological. Each of the indicators is informed by one or more attributes. The attributes fall into three primary categories: numeric, descriptive, and map-derived, each of which is to be interpreted by an interdisciplinary team at the unit level. The descriptive and map-derived attributes are considered to be semi-quantitative or based on professional judgement of the team. The original description of the attributes anticipated that many of them would be improved as better data and information become available. With the advances in geographic information systems and remote sensing

The Watershed Transform : Definitions, Algorithms and Parallelization Strategies

NARCIS (Netherlands)

Roerdink, Jos B.T.M.; Meijster, Arnold

2000-01-01

The watershed transform is the method of choice for image segmentation in the field of mathematical morphology. We present a critical review of several definitions of the watershed transform and the associated sequential algorithms, and discuss various issues which often cause confusion in the

78 FR 21590 - Coconino National Forest; Arizona; Flagstaff Watershed Protection Project

Science.gov (United States)

2013-04-11

... watersheds around Flagstaff. Specifically, two key areas have been identified for analysis and treatment... Mary Watershed. The FWPP analysis area includes portions of the Coconino National Forest that have... Watershed Protection Project, and is participating in the planning and analysis process. Responsible...

Water quality and mass transport in four watersheds in eastern Puerto Rico: Chapter E in Water quality and landscape processes of four watersheds in eastern Puerto Rico

Science.gov (United States)

Stallard, Robert F.; Murphy, Sheila F.; Murphy, Sheila F.; Stallard, Robert F.

2012-01-01

Water quality of four small watersheds in eastern Puerto Rico has been monitored since 1991 as part of the U.S. Geological Survey's Water, Energy, and Biogeochemical Budgets program. These watersheds represent a montane, humid-tropical environment and differ in geology and land cover. Two watersheds are located on granitic rocks, and two are located on volcaniclastic rock. For each bedrock type, one watershed is covered with mature rainforest in the Luquillo Mountains, and the other watershed is undergoing reforestation after being affected by agricultural practices typical of eastern Puerto Rico. A subwatershed of the Icacos watershed, the Guabá, was also monitored to examine scaling effects. The water quality of the rivers draining forest, in the Icacos and Guabá (granitic watersheds) and Mameyes (a volcaniclastic watershed), show little contamination by human activities. The water is well oxygenated and has a nearly neutral pH, and nutrient concentrations are low. Concentrations of nutrients in the disturbed watersheds, the Cayaguás (granitic rock) and Canóvanas (volcaniclastic rock), are greater than in the forested watersheds, indicating some inputs from human activities. High in-stream productivity in the Canóvanas watershed leads to occasional oxygen and calcite supersaturation and carbon dioxide undersaturation. Suspended sediment concentrations in all watersheds are low, except during major storms. Most dissolved constituents derived from bedrock weathering or atmospheric deposition (including sodium, magnesium, calcium, silica, alkalinity, and chloride) decrease in concentration with increasing runoff, reflecting dilution from increased proportions of overland or near-surface flow. Strongly bioactive constituents (dissolved organic carbon, potassium, nitrate, ammonium ion, and phosphate) commonly display increasing concentration with increasing runoff, regardless of their ultimate origin (bedrock or atmosphere). The concentrations of many of the

Beyond formal groups: neighboring acts and watershed protection in Appalachia

Directory of Open Access Journals (Sweden)

Heather Lukacs

2016-09-01

Full Text Available This paper explores how watershed organizations in Appalachia have persisted in addressing water quality issues in areas with a history of coal mining. We identified two watershed groups that have taken responsibility for restoring local creeks that were previously highly degraded and sporadically managed. These watershed groups represent cases of self-organized commons governance in resource-rich, economically poor Appalachian communities. We describe the extent and characteristics of links between watershed group volunteers and watershed residents who are not group members. Through surveys, participant observation, and key-informant consultation, we found that neighbors – group members as well as non-group-members – supported the group's function through informal neighboring acts. Past research has shown that local commons governance institutions benefit from being nested in supportive external structures. We found that the persistence and success of community watershed organizations depends on the informal participation of local residents, affirming the necessity of looking beyond formal, organized groups to understand the resources, expertise, and information needed to address complex water pollution at the watershed level. Our findings augment the concept of nestedness in commons governance to include that of a formal organization acting as a neighbor that exchanges informal neighboring acts with local residents. In this way, we extend the concept of neighboring to include interactions between individuals and a group operating in the same geographic area.

An Alternative Algorithm for Computing Watersheds on Shared Memory Parallel Computers

NARCIS (Netherlands)

Meijster, A.; Roerdink, J.B.T.M.

1995-01-01

In this paper a parallel implementation of a watershed algorithm is proposed. The algorithm can easily be implemented on shared memory parallel computers. The watershed transform is generally considered to be inherently sequential since the discrete watershed of an image is defined using recursion.

NASA-modified precipitation products to improve USEPA nonpoint source water quality modeling for the Chesapeake Bay.

Science.gov (United States)

Nigro, Joseph; Toll, David; Partington, Ed; Ni-Meister, Wenge; Lee, Shihyan; Gutierrez-Magness, Angelica; Engman, Ted; Arsenault, Kristi

2010-01-01

The USEPA has estimated that over 20,000 water bodies within the United States do not meet water quality standards. One of the regulations in the Clean Water Act of 1972 requires states to monitor the total maximum daily load, or the amount of pollution that can be carried by a water body before it is determined to be "polluted," for any watershed in the United States (Copeland, 2005). In response to this mandate, the USEPA developed Better Assessment Science Integrating Nonpoint Sources (BASINS) as a decision support tool for assessing pollution and to guide the decision-making process for improving water quality. One of the models in BASINS, the Hydrological Simulation Program-Fortran (HSPF), computes continuous streamflow rates and pollutant concentration at each basin outlet. By design, precipitation and other meteorological data from weather stations serve as standard model input. In practice, these stations may be unable to capture the spatial heterogeneity of precipitation events, especially if they are few and far between. An attempt was made to resolve this issue by substituting station data with NASA-modified/NOAA precipitation data. Using these data within HSPF, streamflow was calculated for seven watersheds in the Chesapeake Bay Basin during low flow periods, convective storm periods, and annual flows. In almost every case, the modeling performance of HSPF increased when using the NASA-modified precipitation data, resulting in better streamflow statistics and, potentially, in improved water quality assessment.

Computation of watersheds based on parallel graph algorithms

NARCIS (Netherlands)

Meijster, A.; Roerdink, J.B.T.M.; Maragos, P; Schafer, RW; Butt, MA

1996-01-01

In this paper the implementation of a parallel watershed algorithm is described. The algorithm has been implemented on a Cray J932, which is a shared memory architecture with 32 processors. The watershed transform has generally been considered to be inherently sequential, but recently a few research

Baybook: A Guide to Reducing Water Pollution at Home.

Science.gov (United States)

Citizens Program for the Chesapeake Bay, Inc., Baltimore, MD.

Developed to increase public awareness of the Chesapeake Bay ecosystem, this guide provides information and suggestions for improving the quality of life in the Bay area. Contents include background information and a "what can you do" section on separate topics related to: (1) resources of the Chesapeake Bay watershed; (2) streambank…

Joint analysis of input and parametric uncertainties in watershed water quality modeling: A formal Bayesian approach

Science.gov (United States)

Han, Feng; Zheng, Yi

2018-06-01

Significant Input uncertainty is a major source of error in watershed water quality (WWQ) modeling. It remains challenging to address the input uncertainty in a rigorous Bayesian framework. This study develops the Bayesian Analysis of Input and Parametric Uncertainties (BAIPU), an approach for the joint analysis of input and parametric uncertainties through a tight coupling of Markov Chain Monte Carlo (MCMC) analysis and Bayesian Model Averaging (BMA). The formal likelihood function for this approach is derived considering a lag-1 autocorrelated, heteroscedastic, and Skew Exponential Power (SEP) distributed error model. A series of numerical experiments were performed based on a synthetic nitrate pollution case and on a real study case in the Newport Bay Watershed, California. The Soil and Water Assessment Tool (SWAT) and Differential Evolution Adaptive Metropolis (DREAM(ZS)) were used as the representative WWQ model and MCMC algorithm, respectively. The major findings include the following: (1) the BAIPU can be implemented and used to appropriately identify the uncertain parameters and characterize the predictive uncertainty; (2) the compensation effect between the input and parametric uncertainties can seriously mislead the modeling based management decisions, if the input uncertainty is not explicitly accounted for; (3) the BAIPU accounts for the interaction between the input and parametric uncertainties and therefore provides more accurate calibration and uncertainty results than a sequential analysis of the uncertainties; and (4) the BAIPU quantifies the credibility of different input assumptions on a statistical basis and can be implemented as an effective inverse modeling approach to the joint inference of parameters and inputs.

Short Term Sediment Exchange Between Marshes and Bays Using Beryllium-7 as a Tracer, Fourleague Bay, Louisiana.

Science.gov (United States)

Restreppo, G. A.; Bentley, S. J.; Xu, K.; Wang, J.

2016-12-01

Modern delta models focus on the availability and exchange of coarse sediment as one of the major factors of deltaic growth or decay. Fine-grained sediment exchange within a river's delta is relatively poorly understood, as is the impact that this exchange has on land building and land loss. To better understand the dynamics of fine grain sediment exchange between river mouth, adjacent bays, and marshland, sediment cores from Fourleague Bay, LA, were collected and analyzed for 7Be, a naturally occurring radioisotope that serves as a marker for recently deposited sediment. Time-series push cores were collected every two months at ten sites, five located across a longitudinal transect in the middle bay and five located along adjacent marshes, from May 2015 to May 2016. All sites fall within 11 to 28 km of the Atchafalaya Delta, along a gradient extending towards the open ocean. Cores were extruded in 2 cm intervals, dried, ground, and analyzed via gamma spectrometry for the presence of 7Be. Inventories of 7Be were then calculated and used to determine bimonthly sedimentation rates over the course twelve months. Sediment deposition on the bay floor and marsh surface were then compared to Atchafalaya River discharge, wind speed and direction, and wave action. Preliminary results indicate patterns of initial fluvial sediment transfer from river to bay floor, then bay floor to marsh surface, with decreasing fluvial influence towards the open ocean. Sediment transport from bay to marsh appears to be coupled with meteorological forcing that induces bay-floor sediment resuspension and the flooding of marsh surfaces. This indirect mechanism of fluvial sediment supply to wetland surfaces may extend the region of influence for sediment delivery from man-made river-sediment diversions.

Predicting Bacteria Removal by Enhanced Stormwater Control Measures (SCMs) at the Watershed Scale

Science.gov (United States)

Wolfand, J.; Bell, C. D.; Boehm, A. B.; Hogue, T. S.; Luthy, R. G.

2017-12-01

Urban stormwater is a major cause of water quality impairment, resulting in surface waters that fail to meet water quality standards and support their designated uses. Fecal indicator bacteria are present in high concentrations in stormwater and are strictly regulated in receiving waters; yet, their fate and transport in urban stormwater is poorly understood. Stormwater control measures (SCMs) are often used to treat, infiltrate, and release urban runoff, but field measurements show that the removal of bacteria by these structural solutions is limited (median log removal = 0.24, n = 370). Researchers have therefore looked to improve bacterial removal by enhancing SCMs through alterations in flow regimes or adding geomedia such as biochar. The present research seeks to develop a model to predict removal of fecal indicator bacteria by enhanced SCMs at the watershed scale in a semi-arid climate. Using the highly developed Ballona Creek watershed (290 km2) located in Los Angeles County as a case study, a hydrologic model is coupled with a stochastic water quality model to predict E. coli concentration near the outfall of the Ballona Creek, Santa Monica Bay. A hydrologic model was developed using EPA SWMM, calibrated for flow from water year 1998-2006 (NSE = 0.94; R2 = 0.94), and validated from water year 2007-2015 (NSE = 0.90; R2 = 0.93). This bacterial loading model was then linked to EPA SUSTAIN and a SCM bacterial removal script to simulate log removal of bacteria by various SCMs and predict bacterial concentrations in Ballona Creek. Preliminary results suggest small enhancements to SCMs that improve bacterial removal (<0.5 log removal) may offer large benefits to surface water quality and enable communities such as Los Angeles to meet their regulatory requirements.

Metal cycling within mountain pine beetle impacted watersheds of Keystone Gulch, Colorado

Science.gov (United States)

Heil, E. M.; Navarre-Sitchler, A.; Wanty, R. B.

2016-12-01

Metal cycling in mountain watersheds may be altered due to rapid landscape changes. Previous studies have examined the impact of deforestation and wildfires, on the fate and transport of metals in watersheds. However, we have only begun to understand changes in metal cycling in watersheds impacted by the mountain pine beetle. Warming climates and extended droughts have enabled pine beetles to impact larger areas. In these areas tree death occurs an average of three years after the initial infestation. In this short period of time the trees stop transpiring, defoliate, and die. The rapid deposition of pine needles to the forest floor, and subsequent decomposition of the needles, increases organic carbon (OC) availability and release metals that are stored in the impacted watersheds. Consequently, both OC and metal fluxes into and through the beetle-infested watersheds may be larger than those in non-infested watersheds. Four watersheds along Keystone Gulch Rd., located in Keystone, CO, were chosen for soil, water, and needle sampling because of their similar bedrock, drainage area, tree density and type, aspect, and their varying degree of pine beetle infestation. Sequential extractions using simulated rainwater, MgCl2, and pyrophosphate (representing soil pore water, exchangeable fraction, and organically bound metals) were performed on the Keystone Gulch soil samples to develop a better understanding of the distribution of metals in soils. Samples were classified by degree of beetle impact within and between the watersheds. The most obvious differences in the soil extractions between the four watersheds were observed for aluminum and iron and to a slightly lesser extent copper and zinc. In general, aluminum, iron, and zinc concentrations were higher while copper concentrations were lower in soils from less beetle-impacted watersheds. Metal concentrations in stream waters will be evaluated in the context of metal mobility through and out of the watershed.

Workshop to transfer VELMA watershed model results to Washington state tribes and state agencies engaged in watershed restoration and salmon recovery planning

Science.gov (United States)

An EPA Western Ecology Division (WED) watershed modeling team has been working with the Snoqualmie Tribe Environmental and Natural Resources Department to develop VELMA watershed model simulations of the effects of historical and future restoration and land use practices on strea...

Wind River Watershed Restoration: 1999 Annual Report.

Energy Technology Data Exchange (ETDEWEB)

Connolly, Patrick J.

2001-09-01

This document represents work conducted as part of the Wind River Watershed Restoration Project during its first year of funding through the Bonneville Power Administration (BPA). The project is a comprehensive effort involving public and private entities seeking to restore water quality and fishery resources in the basin through cooperative actions. Project elements include coordination, watershed assessment, restoration, monitoring, and education. Entities involved with implementing project components are the Underwood Conservation District (UCD), USDA Forest Service (USFS), U.S. Geological Survey--Columbia River Research Lab (USGS-CRRL), and WA Department of Fish & Wildlife (WDFW). Following categories given in the FY1999 Statement of Work, the broad categories, the related objectives, and the entities associated with each objective (lead entity in boldface) were as follows: Coordination--Objective 1: Coordinate the Wind River watershed Action Committee (AC) and Technical Advisory Committee (TAC) to develop a prioritized list of watershed enhancement projects. Monitoring--Objective 2: Monitor natural production of juvenile, smolt, and adult steelhead in the Wind River subbasin. Objective 3: Evaluate physical habitat conditions in the Wind River subbasin. Assessment--Objective 4: Assess watershed health using an ecosystem-based diagnostic model that will provide the technical basis to prioritize out-year restoration projects. Restoration--Objective 5: Reduce road related sediment sources by reducing road densities to less than 2 miles per square mile. Objective 6: Rehabilitate riparian corridors, flood plains, and channel morphology to reduce maximum water temperatures to less than 61 F, to increase bank stability to greater than 90%, to reduce bankfull width to depth ratios to less than 30, and to provide natural levels of pools and cover for fish. Objective 7: Maintain and evaluate passage for adult and juvenile steelhead at artificial barriers. Education

The Walnut Gulch - Santa Rita Wildland Watershed-Scale LTAR Sites

Science.gov (United States)

Goodrich, D. C.; Heilman, P.; Scott, R. L.; Nearing, M. A.; Moran, M. S.; Nichols, M.; Vivoni, E. R.; Archer, S. R.; Biederman, J.; Naito, A. T.

2015-12-01

The 150 km2 Walnut Gulch Experimental Watershed (WGEW), a Long-Term Agroecosystem Research (LTAR) site, near Tombstone, Arizona was established in 1953 by the USDA-ARS Southwest Watershed Research Center in Tucson. It is one of the most intensively instrumented semiarid experimental watersheds in the world with elevation ranging from 1220 to 1950 m with mean annual temperature and precipitation equal to 17.7°C and 312 mm. Desert shrubs dominate the lower two thirds of the watershed and grasses the upper third. Spatial variation in precipitation is measured with a network of 88 weighing-type recording rain gauges. Surface runoff is quantified over a range of scales (0.002 to 0.06 km2) to characterize interactions between rainfall intensity, soils and vegetation at nine sub-watersheds. Channel network processes and rainfall spatial variability are studied using 11 nested watersheds (2 to 150 km2). Sediment from the small sub-watersheds is sampled. Meteorological, soil moisture and temperature, and energy/water/CO2 flux measurements are made within two vegetation/soil complexes. Parallel investigations dating back to 1974 have also been conducted on eight small experimental watersheds at the Santa Rita Experimental Range (SRER) 80 km west of Walnut Gulch. In contrast to the creosote bush-grass WGEW, the mesquite-grass SRER is publicly owned, which ensures control and consistent reporting of management for research purposes. A key LTAR objective is to contrast a "business as usual" to an alternate management strategy presumed to have the potential of significantly improving forage and livestock production and diversification of ecosystem services. Consequently, a new ARS-U. of Arizona-Arizona State U. partnership will assess the watershed-scale impacts of brush management, a common land use practice typically applied in conjunction with livestock grazing, on a suite of ecosystem services at the SRER including provisioning (forage production, water yield), supporting

Contributions of systematic tile drainage to watershed-scale phosphorus transport.

Science.gov (United States)

King, Kevin W; Williams, Mark R; Fausey, Norman R

2015-03-01

Phosphorus (P) transport from agricultural fields continues to be a focal point for addressing harmful algal blooms and nuisance algae in freshwater systems throughout the world. In humid, poorly drained regions, attention has turned to P delivery through subsurface tile drainage. However, research on the contributions of tile drainage to watershed-scale P losses is limited. The objective of this study was to evaluate long-term P movement through tile drainage and its manifestation at the watershed outlet. Discharge data and associated P concentrations were collected for 8 yr (2005-2012) from six tile drains and from the watershed outlet of a headwater watershed within the Upper Big Walnut Creek watershed in central Ohio. Results showed that tile drainage accounted for 47% of the discharge, 48% of the dissolved P, and 40% of the total P exported from the watershed. Average annual total P loss from the watershed was 0.98 kg ha, and annual total P loss from the six tile drains was 0.48 kg ha. Phosphorus loads in tile and watershed discharge tended to be greater in the winter, spring, and fall, whereas P concentrations were greatest in the summer. Over the 8-yr study, P transported in tile drains represented 90% of all measured concentrations exceeded recommended levels (0.03 mg L) for minimizing harmful algal blooms and nuisance algae. Thus, the results of this study show that in systematically tile-drained headwater watersheds, the amount of P delivered to surface waters via tile drains cannot be dismissed. Given the amount of P loss relative to typical application rates, development and implementation of best management practices (BMPs) must jointly consider economic and environmental benefits. Specifically, implementation of BMPs should focus on late fall, winter, and early spring seasons when most P loading occurs. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Effects of mountain agriculture on nutrient cycling at upstream watersheds

Science.gov (United States)

Lin, T.-C.; Shaner, P. L.; Wang, L.-J.; Shih, Y.-T.; Wang, C.-P.; Huang, G.-H.; Huang, J.-C.

2015-05-01

The expansion of agriculture to rugged mountains can exacerbate negative impacts of agriculture activities on ecosystem function. In this study, we monitored streamwater chemistry of four watersheds with varying proportions of agricultural lands (0.4, 3, 17, 22%) and rainfall chemistry of two of the four watersheds at Feitsui Reservoir Watershed in northern Taiwan to examine the effects of agriculture on watershed nutrient cycling. We found that the greater the proportions of agricultural lands, the higher the ion concentrations, which is evident for fertilizer-associated ions (NO3-, K+) but not for ions that are rich in soils (SO42-, Ca2+, Mg2+), suggesting that agriculture enriched fertilizer-associated nutrients in streamwater. The watershed with the highest proportion of agricultural lands had higher concentrations of ions in rainfall and lower nutrient retention capacity (i.e. higher output-input ratio of ions) compared to the relatively pristine watershed, suggesting that agriculture can influence atmospheric deposition of nutrients and a system's ability to retain nutrients. Furthermore, we found that a forested watershed downstream of agricultural activities can dilute the concentrations of fertilizer-associated ions (NO3-, K+) in streamwater by more than 70%, indicating that specific landscape configurations help mitigate nutrient enrichment to aquatic systems. We estimated that agricultural lands at our study site contributed approximately 400 kg ha-1 yr-1 of NO3-N and 260 kg ha-1 yr-1 of PO4-P output via streamwater, an order of magnitude greater than previously reported around the globe and can only be matched by areas under intense fertilizer use. Furthermore, we re-constructed watershed nutrient fluxes to show that excessive leaching of N and P, and additional loss of N to the atmosphere via volatilization and denitrification, can occur under intense fertilizer use. In summary, this study demonstrated the pervasive impacts of agriculture activities

Contrasting nitrogen fate in watersheds using agricultural and water quality information

Science.gov (United States)

Essaid, Hedeff I.; Baker, Nancy T.; McCarthy, Kathleen A.

2016-01-01

Surplus nitrogen (N) estimates, principal component analysis (PCA), and end-member mixing analysis (EMMA) were used in a multisite comparison contrasting the fate of N in diverse agricultural watersheds. We applied PCA-EMMA in 10 watersheds located in Indiana, Iowa, Maryland, Nebraska, Mississippi, and Washington ranging in size from 5 to 1254 km2 with four nested watersheds. Watershed Surplus N was determined by subtracting estimates of crop uptake and volatilization from estimates of N input from atmospheric deposition, plant fixation, fertilizer, and manure for the period from 1987 to 2004. Watershed average Surplus N ranged from 11 to 52 kg N ha−1 and from 9 to 32% of N input. Solute concentrations in streams, overland runoff, tile drainage, groundwater (GW), streambeds, and the unsaturated zone were used in the PCA-EMMA procedure to identify independent components contributing to observed stream concentration variability and the end-members contributing to streamflow and NO3 load. End-members included dilute runoff, agricultural runoff, benthic-processing, tile drainage, and oxic and anoxic GW. Surplus N was larger in watersheds with more permeable soils (Washington, Nebraska, and Maryland) that allowed greater infiltration, and oxic GW was the primary source of NO3 load. Subsurface transport of NO3 in these watersheds resulted in some removal of Surplus N by denitrification. In less permeable watersheds (Iowa, Indiana, and Mississippi), NO3 was rapidly transported to the stream by tile drainage and runoff with little removal. Evidence of streambed removal of NO3 by benthic diatoms was observed in the larger watersheds.

BOOK REVIEW OF "CHESAPEAKE BAY BLUES: SCIENCE, POLITICS, AND THE STRUGGLE TO SAVE THE BAY"

Science.gov (United States)

This is a book review of "Chesapeake Bay Blues: Science, Politics, and the Struggle to Save the Bay". This book is very well written and provides an easily understandable description of the political challenges faced by those proposing new or more stringent environmental regulat...

Latest results from Daya Bay

Science.gov (United States)

Vorobel, Vit; Daya Bay Collaboration

2017-07-01

The Daya Bay Reactor Neutrino Experiment was designed to measure θ 13, the smallest mixing angle in the three-neutrino mixing framework, with unprecedented precision. The experiment consists of eight functionally identical detectors placed underground at different baselines from three pairs of nuclear reactors in South China. Since Dec. 2011, the experiment has been running stably for more than 4 years, and has collected the largest reactor anti-neutrino sample to date. Daya Bay is able to greatly improve the precision on θ 13 and to make an independent measurement of the effective mass splitting in the electron antineutrino disappearance channel. Daya Bay can also perform a number of other precise measurements, such as a high-statistics determination of the absolute reactor antineutrino flux and spectrum, as well as a search for sterile neutrino mixing, among others. The most recent results from Daya Bay are discussed in this paper, as well as the current status and future prospects of the experiment.

Tumor prevalence and biomarkers of genotoxicity in brown bullhead (Ameiurus nebulosus) in Chesapeake Bay tributaries

Energy Technology Data Exchange (ETDEWEB)

Pinkney, Alfred E., E-mail: Fred_Pinkney@fws.gov [U.S. Fish and Wildlife Service, Chesapeake Bay Field Office, 177 Admiral Cochrane Drive, Annapolis, MD 21401 (United States); Harshbarger, John C., E-mail: jcharshbarger@verizon.net [Department of Pathology, George Washington University Medical Center, 2300 I Street, NW, Washington, DC 20037 (United States); Karouna-Renier, Natalie K., E-mail: nkarouna@usgs.gov [U.S. Geological Survey, Patuxent Wildlife Research Center, BARC, Bldg. 308, Beltsville, MD 20705 (United States); Jenko, Kathryn [U.S. Geological Survey, Patuxent Wildlife Research Center, BARC, Bldg. 308, Beltsville, MD 20705 (United States); Balk, Lennart, E-mail: lennart.balk@itm.su.se [Department of Applied Environmental Science (ITM), Stockholm University SE-106 91, Stockholm (Sweden); Skarphe Latin-Small-Letter-Eth insdottir, Halldora; Liewenborg, Birgitta [Department of Applied Environmental Science (ITM), Stockholm University SE-106 91, Stockholm (Sweden); Rutter, Michael A., E-mail: mar36@psu.edu [Department of Mathematics, Penn State Erie, The Behrend College, 5091 Station Road, Erie, PA 16563 (United States)

2011-12-01

We surveyed four Chesapeake Bay tributaries for skin and liver tumors in brown bullhead (Ameiurus nebulosus). We focused on the South River, where the highest skin tumor prevalence (53%) in the Bay watershed had been reported. The objectives were to 1) compare tumor prevalence with nearby rivers (Severn and Rhode) and a more remote river (Choptank); 2) investigate associations between tumor prevalence and polynuclear aromatic hydrocarbons (PAHs) and alkylating agents; and 3) statistically analyze Chesapeake Bay bullhead tumor data from 1992 through 2008. All four South River collections exhibited high skin tumor prevalence (19% to 58%), whereas skin tumor prevalence was 2%, 10%, and 52% in the three Severn collections; 0% and 2% in the Choptank collections; and 5.6% in the Rhode collection. Liver tumor prevalence was 0% to 6% in all but one South River collection (20%) and 0% to 6% in the three other rivers. In a subset of samples, PAH-like biliary metabolites and {sup 32}P-DNA adducts were used as biomarkers of exposure and response to polycyclic aromatic compounds (PACs). Adducts from alkylating agents were detected as O6-methyl-2 Prime -deoxyguanosine (O6Me-dG) and O6-ethyl-2 Prime -deoxyguanosine (O6Et-dG) modified DNA. Bullheads from the contaminated Anacostia River were used as a positive control for DNA adducts. {sup 32}P-DNA adduct concentrations were significantly higher in Anacostia bullhead livers compared with the other rivers. We identified alkyl DNA adducts in bullhead livers from the South and Anacostia, but not the Choptank. Neither the PAH-like bile metabolite data, sediment PAH data, nor the DNA adduct data suggest an association between liver or skin tumor prevalence and exposure to PACs or alkylating agents in the South, Choptank, Severn, or Rhode rivers. Logistic regression analysis of the Chesapeake Bay database revealed that sex and length were significant covariates for liver tumors and length was a significant covariate for skin tumors

Tumor prevalence and biomarkers of genotoxicity in brown bullhead (Ameiurus nebulosus) in Chesapeake Bay tributaries

International Nuclear Information System (INIS)

Pinkney, Alfred E.; Harshbarger, John C.; Karouna-Renier, Natalie K.; Jenko, Kathryn; Balk, Lennart; Skarphéðinsdóttir, Halldóra; Liewenborg, Birgitta; Rutter, Michael A.

2011-01-01

We surveyed four Chesapeake Bay tributaries for skin and liver tumors in brown bullhead (Ameiurus nebulosus). We focused on the South River, where the highest skin tumor prevalence (53%) in the Bay watershed had been reported. The objectives were to 1) compare tumor prevalence with nearby rivers (Severn and Rhode) and a more remote river (Choptank); 2) investigate associations between tumor prevalence and polynuclear aromatic hydrocarbons (PAHs) and alkylating agents; and 3) statistically analyze Chesapeake Bay bullhead tumor data from 1992 through 2008. All four South River collections exhibited high skin tumor prevalence (19% to 58%), whereas skin tumor prevalence was 2%, 10%, and 52% in the three Severn collections; 0% and 2% in the Choptank collections; and 5.6% in the Rhode collection. Liver tumor prevalence was 0% to 6% in all but one South River collection (20%) and 0% to 6% in the three other rivers. In a subset of samples, PAH-like biliary metabolites and 32 P-DNA adducts were used as biomarkers of exposure and response to polycyclic aromatic compounds (PACs). Adducts from alkylating agents were detected as O6-methyl-2′-deoxyguanosine (O6Me-dG) and O6-ethyl-2′-deoxyguanosine (O6Et-dG) modified DNA. Bullheads from the contaminated Anacostia River were used as a positive control for DNA adducts. 32 P-DNA adduct concentrations were significantly higher in Anacostia bullhead livers compared with the other rivers. We identified alkyl DNA adducts in bullhead livers from the South and Anacostia, but not the Choptank. Neither the PAH-like bile metabolite data, sediment PAH data, nor the DNA adduct data suggest an association between liver or skin tumor prevalence and exposure to PACs or alkylating agents in the South, Choptank, Severn, or Rhode rivers. Logistic regression analysis of the Chesapeake Bay database revealed that sex and length were significant covariates for liver tumors and length was a significant covariate for skin tumors. - Highlights: ► We

Watershed Modeling System Hydrological Simulation Program; Watershed Model User Documentation and Tutorial

National Research Council Canada - National Science Library

Dellman, Patrick

2002-01-01

.... This analysis helps predict possible environmental problems in the watershed. With the growing need to care for and monitor the effects of man on the environment, it became apparent that a method for rapid analysis of those effects was needed...

Scientists and Stakeholders in the Chesapeake Bay: How the Mid-Atlantic RISA Strengthens Climate Resilience Through Participatory Decision-Making Processes

Science.gov (United States)

Knopman, D.; Berg, N.

2017-12-01

The NOAA Mid-Atlantic Regional Integrated Sciences and Assessments (MARISA) program was formed in September 2016 to increase climate resilience in the Mid-Atlantic, with an initial focus on the Chesapeake Bay Watershed. In this talk, we will discuss how the program's unique structure and approach are designed to advance resilience to a changing climate through improved data, place-based decision support, and public engagement. Emphasis will be placed on MARISA's approach to integrating stakeholder perspectives from the onset of decision scoping, through the creation of actionable data sets, and concluding with the co-development of adaptation strategies between the scientific community, decision-makers, and stakeholders. Specific examples of this process involving climate-sensitive decisions and investments regarding water resources, land management, and urban corridors will be discussed.

Watershed-Scale Modeling of Land-Use and Altered Environment Impacts on Aquatic Weed Growth in the Delta

Science.gov (United States)

Bubenheim, David; Potter, Christopher; Zhang, Minghua

2016-01-01

The California Sacramento-San Joaquin River Delta is the hub for California's water supply, conveying water from Northern to Southern California agriculture and communities while supporting important ecosystem services, agriculture, and communities in the Delta. Changes in climate, long-term drought, and water quality have all been suspected as playing role in the dramatic expansion of invasive aquatic plants and their impact on ecosystems of the San Francisco Bay / California Delta complex. NASA Ames Research Center, USDA-Agricultural Research Service, the State of California, UC Davis, and local governments have partnered under a USDA sponsored project (DRAAWP) to develop science-based, adaptive-management strategies for invasive aquatic plants in Sacramento-San Joaquin Delta. Critical to developing management strategies is to understand how the Delta is affected by both the magnitude of fluctuations in land-use and climate / drought induced altered environments and how the plants respond to these altered environments. We utilize the Soil Water Assessment Tool (SWAT), a watershed-scale model developed to quantify the impact of land management practices in large and complex watersheds on water quality, as the backbone for a customized Delta model - Delta-SWAT. The model uses land-use, soils, elevation, and hydrologic routing to characterize pesticide and nutrient transport from the Sacramento and San Joaquin rivers watersheds and loading into the Delta. Land-use within the Delta, as well as water extraction to supply those functions, and the resulting return of water to Delta waterways are included in Delta-SWAT. Hydrologic transport within the Delta has required significant attention to address the lack of elevation driven transport processes. Delta-SWAT water quality trend estimates are compared with water quality monitoring conducted throughout the Delta. Aquatic plant response to water quality and other environmental factors is carried out using a customized

Export of Dissolved Organic Carbon following Prescribed Fire on Forested Watersheds: Implications for Watershed Management for Drinking Water Supply

Science.gov (United States)

Zhang, W.; Olivares, C. I.; Uzun, H.; Erdem, C. U.; Trettin, C.; Liu, Y.; Robinson, E. R.; Karanfil, T.; Chow, A. T.

2016-12-01

Detrital material in forest watersheds is the major terrestrial source of dissolved organic matter (DOM) and disinfection byproduct (DBP) precursors in surface source waters, but it is also the fuel for forest fires. Prescribed fire, as a fuel reduction technique is intended to reduce the amount of forest detritus, and therefore the risk of wildfire. Accordingly, periodic prescribed fire can reduce the accumulation of detritus on forest floor and the amount of DOM export after forest treatments. To evaluate the effects of prescribed fire on water quality, we conducted a controlled study on a paired first-order watershed system that includes a 160 ha treatment watershed (WS77) and 200 ha control watershed (WS80) on the Santee Experimental Forest, near Charleston South Carolina. WS77 has been used for prescribed fire research since the 1960's, the current experimental burn occurred on April, 2016. WS80 has not been managed or burned for at least 55 years. Gauging stations were equipped with in-situ TOC sensors and flow-proportional water samplers for monitoring temporal trends on water quality. Water samples taken from the first runoff event from both watersheds including rising limb, peak discharge, and falling limb were used for detailed chemical characterizations including DOC and nutrient concentrations, coagulation efficiency, and DBP formation such as trihalomethanes (THMs) and halocacetic acids (HAAs) from chlorination as well as N-nitrosodimethylamine (NDMA) from chlorination, and chemical formula assignment on DOM using Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR-MS) before and after chlorination and chloramination. Preliminary FT-ICR-MS data shows that DOM chemical compositions are different between raw samples collected from WS77 and WS80. Chlorination resulted in a shift toward lower molecular mass compared to the raw materials. While chloramination did not cause a drastic mass shift, such a treatment also produced DOM moieties

Exploring an innovative watershed management approach: From feasibility to sustainability

International Nuclear Information System (INIS)

Said, A.; Sehlke, G.; Stevens, D.K.; Sorensen, D.; Walker, W.; Hardy, T.; Glover, T.

2006-01-01

Watershed management is dedicated to solving watershed problems on a sustainable basis. Managing watershed development on a sustainable basis usually entails a balance between the needs of humans and nature, both in the present and in the future. From a watershed or water resources development basis, these problems can be classified into five general categories: lack of water quantity, deterioration in water quality, ecological impacts, weak public participation, and weak economic value. The first three categories can be combined to make up physical sustainability while the last two categories can be defined as social and economic sustainability. Therefore, integrated watershed management should be designed to achieve physical sustainability utilizing, to the greatest extent possible, public participation in an economically viable manner. This study demonstrates an innovative approach using scientific, social, and motivational feasibilities that can be used to improve watershed management. Scientific feasibility is tied to the nature of environmental problems and the scientific means to solve them. Social feasibility is associated with public participation. Motivational feasibility is related to economic stimulation for the stakeholders to take actions. The ecological impacts, lack of water quantity and deterioration in water quality are problems that need scientific means in order to improve watershed health. However, the implementation of these means is typically not achievable without the right public participation. In addition, public participation is typically accelerated by economic motivation for the stakeholders to use the resources in a manner that improves watershed health. The Big Lost River in south-central Idaho has been used as an illustration for implementing scientific, social and motivational feasibilities and in a manner that can achieve sustainability relative to water resources management. However, the same approach can be used elsewhere after

Exploring an innovative watershed management approach: From feasibility to sustainability

Energy Technology Data Exchange (ETDEWEB)

Said, A. [Department of Civil and Environmental Engineering, University of South Florida, Tampa, FL 33620 (United States); Sehlke, G. [Idaho National Laboratory, Idaho Falls, ID 83415 (United States); Stevens, D.K.; Sorensen, D.; Walker, W.; Hardy, T. [Civil and Environmental Department, Utah State University, Logan, UT 84321 (United States); Glover, T. [Economics Department, Utah State University, Logan, UT 84321 (United States)

2006-10-15

Watershed management is dedicated to solving watershed problems on a sustainable basis. Managing watershed development on a sustainable basis usually entails a balance between the needs of humans and nature, both in the present and in the future. From a watershed or water resources development basis, these problems can be classified into five general categories: lack of water quantity, deterioration in water quality, ecological impacts, weak public participation, and weak economic value. The first three categories can be combined to make up physical sustainability while the last two categories can be defined as social and economic sustainability. Therefore, integrated watershed management should be designed to achieve physical sustainability utilizing, to the greatest extent possible, public participation in an economically viable manner. This study demonstrates an innovative approach using scientific, social, and motivational feasibilities that can be used to improve watershed management. Scientific feasibility is tied to the nature of environmental problems and the scientific means to solve them. Social feasibility is associated with public participation. Motivational feasibility is related to economic stimulation for the stakeholders to take actions. The ecological impacts, lack of water quantity and deterioration in water quality are problems that need scientific means in order to improve watershed health. However, the implementation of these means is typically not achievable without the right public participation. In addition, public participation is typically accelerated by economic motivation for the stakeholders to use the resources in a manner that improves watershed health. The Big Lost River in south-central Idaho has been used as an illustration for implementing scientific, social and motivational feasibilities and in a manner that can achieve sustainability relative to water resources management. However, the same approach can be used elsewhere after

Topography significantly influencing low flows in snow-dominated watersheds

Science.gov (United States)

Li, Qiang; Wei, Xiaohua; Yang, Xin; Giles-Hansen, Krysta; Zhang, Mingfang; Liu, Wenfei

2018-03-01

Watershed topography plays an important role in determining the spatial heterogeneity of ecological, geomorphological, and hydrological processes. Few studies have quantified the role of topography in various flow variables. In this study, 28 watersheds with snow-dominated hydrological regimes were selected with daily flow records from 1989 to 1996. These watersheds are located in the Southern Interior of British Columbia, Canada, and range in size from 2.6 to 1780 km2. For each watershed, 22 topographic indices (TIs) were derived, including those commonly used in hydrology and other environmental fields. Flow variables include annual mean flow (Qmean), Q10 %, Q25 %, Q50 %, Q75 %, Q90 %, and annual minimum flow (Qmin), where Qx % is defined as the daily flow that occurred each year at a given percentage (x). Factor analysis (FA) was first adopted to exclude some redundant or repetitive TIs. Then, multiple linear regression models were employed to quantify the relative contributions of TIs to each flow variable in each year. Our results show that topography plays a more important role in low flows (flow magnitudes ≤ Q75 %) than high flows. However, the effects of TIs on different flow magnitudes are not consistent. Our analysis also determined five significant TIs: perimeter, slope length factor, surface area, openness, and terrain characterization index. These can be used to compare watersheds when low flow assessments are conducted, specifically in snow-dominated regions with the watershed size less than several thousand square kilometres.

Effects of mountain tea plantations on nutrient cycling at upstream watersheds

Science.gov (United States)

Lin, T.-C.; Shaner, P.-J. L.; Wang, L.-J.; Shih, Y.-T.; Wang, C.-P.; Huang, G.-H.; Huang, J.-C.

2015-11-01

The expansion of agriculture to rugged mountains can exacerbate negative impacts of agricultural activities on ecosystem function. In this study, we monitored streamwater and rainfall chemistry of mountain watersheds at the Feitsui Reservoir Watershed in northern Taiwan to examine the effects of agriculture on watershed nutrient cycling. We found that the greater the proportion of tea plantation cover, the higher the concentrations of fertilizer-associated ions (NO3-, K+) in streamwater of the four mountain watersheds examined; on the other hand, the concentrations of the ions that are rich in soils (SO42-, Ca2+, Mg2+) did not increase with the proportion of tea plantation cover, suggesting that agriculture enriched fertilizer-associated nutrients in streamwater. Of the two watersheds for which rainfall chemistry was available, the one with higher proportion of tea plantation cover had higher concentrations of ions in rainfall and retained less nitrogen in proportion to input compared to the more pristine watershed, suggesting that agriculture can influence atmospheric deposition of nutrients and a system's ability to retain nutrients. As expected, we found that a forested watershed downstream of agricultural activities can dilute the concentrations of NO3- in streamwater by more than 70 %, indicating that such a landscape configuration helps mitigate nutrient enrichment in aquatic systems even for watersheds with steep topography. We estimated that tea plantation at our study site contributed approximately 450 kg ha-1 yr-1 of NO3-N via streamwater, an order of magnitude greater than previously reported for agricultural lands around the globe, which can only be matched by areas under intense fertilizer use. Furthermore, we constructed watershed N fluxes to show that excessive leaching of N, and additional loss to the atmosphere via volatilization and denitrification can occur under intense fertilizer use. In summary, this study demonstrated the pervasive impacts of

The hydrological calibration and validation of a complexly-linked watershed reservoir model for the Occoquan watershed, Virginia

Science.gov (United States)

Xu, Zhongyan; Godrej, Adil N.; Grizzard, Thomas J.

2007-10-01

SummaryRunoff models such as HSPF and reservoir models such as CE-QUAL-W2 are used to model water quality in watersheds. Most often, the models are independently calibrated to observed data. While this approach can achieve good calibration, it does not replicate the physically-linked nature of the system. When models are linked by using the model output from an upstream model as input to a downstream model, the physical reality of a continuous watershed, where the overland and waterbody portions are parts of the whole, is better represented. There are some additional challenges in the calibration of such linked models, because the aim is to simulate the entire system as a whole, rather than piecemeal. When public entities are charged with model development, one of the driving forces is to use public-domain models. This paper describes the use of two such models, HSPF and CE-QUAL-W2, in the linked modeling of the Occoquan watershed located in northern Virginia, USA. The description of the process is provided, and results from the hydrological calibration and validation are shown. The Occoquan model consists of six HSPF and two CE-QUAL-W2 models, linked in a complex way, to simulate two major reservoirs and the associated drainage areas. The overall linked model was calibrated for a three-year period and validated for a two-year period. The results show that a successful calibration can be achieved using the linked approach, with moderate additional effort. Overall flow balances based on the three-year calibration period at four stream stations showed agreement ranging from -3.95% to +3.21%. Flow balances for the two reservoirs, compared via the daily water surface elevations, also showed good agreement ( R2 values of 0.937 for Lake Manassas and 0.926 for Occoquan Reservoir), when missing (un-monitored) flows were included. Validation of the models ranged from poor to fair for the watershed models and excellent for the waterbody models, thus indicating that the

Geospatial techniques for developing a sampling frame of watersheds across a region

Science.gov (United States)

Gresswell, Robert E.; Bateman, Douglas S.; Lienkaemper, George; Guy, T.J.

2004-01-01

Current land-management decisions that affect the persistence of native salmonids are often influenced by studies of individual sites that are selected based on judgment and convenience. Although this approach is useful for some purposes, extrapolating results to areas that were not sampled is statistically inappropriate because the sampling design is usually biased. Therefore, in recent investigations of coastal cutthroat trout (Oncorhynchus clarki clarki) located above natural barriers to anadromous salmonids, we used a methodology for extending the statistical scope of inference. The purpose of this paper is to apply geospatial tools to identify a population of watersheds and develop a probability-based sampling design for coastal cutthroat trout in western Oregon, USA. The population of mid-size watersheds (500-5800 ha) west of the Cascade Range divide was derived from watershed delineations based on digital elevation models. Because a database with locations of isolated populations of coastal cutthroat trout did not exist, a sampling frame of isolated watersheds containing cutthroat trout had to be developed. After the sampling frame of watersheds was established, isolated watersheds with coastal cutthroat trout were stratified by ecoregion and erosion potential based on dominant bedrock lithology (i.e., sedimentary and igneous). A stratified random sample of 60 watersheds was selected with proportional allocation in each stratum. By comparing watershed drainage areas of streams in the general population to those in the sampling frame and the resulting sample (n = 60), we were able to evaluate the how representative the subset of watersheds was in relation to the population of watersheds. Geospatial tools provided a relatively inexpensive means to generate the information necessary to develop a statistically robust, probability-based sampling design.

Extended-Maxima Transform Watershed Segmentation Algorithm for Touching Corn Kernels

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Yibo Qin

2013-01-01

Full Text Available Touching corn kernels are usually oversegmented by the traditional watershed algorithm. This paper proposes a modified watershed segmentation algorithm based on the extended-maxima transform. Firstly, a distance-transformed image is processed by the extended-maxima transform in the range of the optimized threshold value. Secondly, the binary image obtained by the preceding process is run through the watershed segmentation algorithm, and watershed ridge lines are superimposed on the original image, so that touching corn kernels are separated into segments. Fifty images which all contain 400 corn kernels were tested. Experimental results showed that the effect of segmentation is satisfactory by the improved algorithm, and the accuracy of segmentation is as high as 99.87%.

Fort Cobb Reservoir Watershed, Oklahoma and Thika River Watershed, Kenya Twinning Pilot Project

Science.gov (United States)

Moriasi, D.; Steiner, J.; Arnold, J.; Allen, P.; Dunbar, J.; Shisanya, C.; Gathenya, J.; Nyaoro, J.; Sang, J.

2007-12-01

The Fort Cobb Reservoir Watershed (FCRW) (830 km2) is a watershed within the HELP Washita Basin, located in Caddo and Washita Counties, OK. It is also a benchmark watershed under USDA's Conservation Effects Assessment Project, a national project to quantify environmental effects of USDA and other conservation programs. Population in south-western Oklahoma, in which FCRW is located, is sparse and decreasing. Agricultural focuses on commodity production (beef, wheat, and row crops) with high costs and low margins. Surface and groundwater resources supply public, domestic, and irrigation water. Fort Cobb Reservoir and contributing stream segments are listed on the Oklahoma 303(d) list as not meeting water quality standards based on sedimentation, trophic level of the lake associated with phosphorus loads, and nitrogen in some stream segments in some seasons. Preliminary results from a rapid geomorphic assessment results indicated that unstable stream channels dominate the stream networks and make a significant but unknown contribution to suspended-sediment loadings. Impairment of the lake for municipal water supply, recreation, and fish and wildlife are important factors in local economies. The Thika River Watershed (TRW) (867 km2) is located in central Kenya. Population in TRW is high and increasing, which has led to a poor land-population ratio with population densities ranging from 250 people/km2 to over 500 people/km2. The poor land-population ratio has resulted in land sub-division, fragmentation, over- cultivation, overgrazing, and deforestation which have serious implications on soil erosion, which poses a threat to both agricultural production and downstream reservoirs. Agricultural focuses mainly on subsistence and some cash crops (dairy cattle, corn, beans, coffee, floriculture and pineapple) farming. Surface and groundwater resources supply domestic, public, and hydroelectric power generation water. Thika River supplies 80% of the water for the city of

Towards a sustainable future in Hudson Bay

International Nuclear Information System (INIS)

Okrainetz, G.

1991-01-01

To date, ca $40-50 billion has been invested in or committed to hydroelectric development on the rivers feeding Hudson Bay. In addition, billions more have been invested in land uses such as forestry and mining within the Hudson Bay drainage basin. However, there has never been a study of the possible impacts on Hudson Bay resulting from this activity. Neither has there been any federal environmental assessment on any of the economic developments that affect Hudson Bay. To fill this gap in knowledge, the Hudson Bay Program was established. The program will not conduct scientific field research but will rather scan the published literature and consult with leading experts in an effort to identify biophysical factors that are likely to be significantly affected by the cumulative influence of hydroelectric and other developments within and outside the region. An annotated bibliography on Hudson Bay has been completed and used to prepare a science overview paper, which will be circulated for comment, revised, and used as the basis for a workshop on cumulative effects in Hudson Bay. Papers will then be commissioned for a second workshop to be held in fall 1993. A unique feature of the program is its integration of traditional ecological knowledge among the Inuit and Cree communities around Hudson Bay with the scientific approach to cumulative impact assessment. One goal of the program is to help these communities bring forward their knowledge in such a way that it can be integrated into the cumulative effects assessment

Characterization and evaluation of controls on post-fire streamflow response across western US watersheds

Science.gov (United States)

Saxe, Samuel; Hogue, Terri S.; Hay, Lauren

2018-02-01

This research investigates the impact of wildfires on watershed flow regimes, specifically focusing on evaluation of fire events within specified hydroclimatic regions in the western United States, and evaluating the impact of climate and geophysical variables on response. Eighty-two watersheds were identified with at least 10 years of continuous pre-fire daily streamflow records and 5 years of continuous post-fire daily flow records. Percent change in annual runoff ratio, low flows, high flows, peak flows, number of zero flow days, baseflow index, and Richards-Baker flashiness index were calculated for each watershed using pre- and post-fire periods. Independent variables were identified for each watershed and fire event, including topographic, vegetation, climate, burn severity, percent area burned, and soils data. Results show that low flows, high flows, and peak flows increase in the first 2 years following a wildfire and decrease over time. Relative response was used to scale response variables with the respective percent area of watershed burned in order to compare regional differences in watershed response. To account for variability in precipitation events, runoff ratio was used to compare runoff directly to PRISM precipitation estimates. To account for regional differences in climate patterns, watersheds were divided into nine regions, or clusters, through k-means clustering using climate data, and regression models were produced for watersheds grouped by total area burned. Watersheds in Cluster 9 (eastern California, western Nevada, Oregon) demonstrate a small negative response to observed flow regimes after fire. Cluster 8 watersheds (coastal California) display the greatest flow responses, typically within the first year following wildfire. Most other watersheds show a positive mean relative response. In addition, simple regression models show low correlation between percent watershed burned and streamflow response, implying that other watershed factors

POTENTIAL HAZARDS OF SEDIMENT IN KENDARI BAY, SOUTHEAST SULAWESI

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Nur Adi Kristanto

2017-07-01

Full Text Available Kendari bay is located in front of Kendari city. There are two harbors in the inner part of bay which very important to support economic activities such as shipping and passenger transportation. The result of coastal characteristic mapping and physical oceanography survey show various coastal morphology, vegetation, weathering processes, sedimentation, currents, and water depth and sea floor morphology. Kendari bay is an enclosed bay; the area is wide in the inner part and narrow in mouth of bay (outlet, the morphology look like a bottle’s neck. Numerous mouth rivers are concentrate around the bay. The rivers load material from land since erosion on land is intensive enough. There is indication that sediment supplies from land trough river mouth not equivalent with outlet capacity. Sediment load is trapped in the inner bay caused the outlet morphology. So high sediment rate play an important role in the process of shallow of water depth in Kendari bay. This condition make the Kendari bay is a prone area of sediment hazard due to height rate of sedimentary process. Therefore, to anticipate the hazards, precaution should be taken related to the Kendari bay as the center of activities in southeast of Sulawesi. The further survey is needed such as marine geotechnique and on land environmental to collect data, which can be used as database for development planning. Key words: Potential hazard, sediment, Kendari Bay Teluk

Watershed management in South Asia: A synoptic review

Science.gov (United States)

Ratna Reddy, V.; Saharawat, Yashpal Singh; George, Biju

2017-08-01

Watershed management (WSM) is the most widely adopted technology in developed as well as developing countries due to its suitability across climatic conditions. Watershed technology is suitable to protect and enhance soil fertility, which is deteriorating at an alarming rate with agricultural intensification in high as well as low rainfall regions. Of late, WSM is considered as an effective poverty alleviation intervention in the rain fed regions in countries like India. This paper aims at providing a basic watershed policy and implementation framework based on a critical review of experiences of WSM initiatives across South Asia. The purpose is to provide cross learnings within South Asia and other developing countries (especially Africa) that are embarking on WSM in recent years. Countries in the region accord differential policy priority and are at different levels of institutional arrangements for implementing WSM programmes. The implementation of watershed interventions is neither scientific nor comprehensive in all the countries limiting the effectiveness (impacts). Implementation of the programmes for enhancing the livelihoods of the communities need to strengthen both technical and institutional aspects. While countries like India and Nepal are yet to strengthen the technical aspects in terms of integrating hydrogeology and biophysical aspects into watershed design, others need to look at these aspects as they move towards strengthening the watershed institutions. Another important challenge in all the countries is regarding the distribution of benefits. Due to the existing property rights in land and water resources coupled with the agrarian structure and uneven distribution and geometry of aquifers access to sub-surface water resources is unevenly distributed across households. Though most of the countries are moving towards incorporating livelihoods components in order to ensure benefits to all sections of the community, not much is done in terms of

McKenzie River Focus Watershed Coordination: Fiscal Year 1998.

Energy Technology Data Exchange (ETDEWEB)

Runyon, John; Davis-Born, Renee

1998-01-01

This report summarizes accomplishments made by the McKenzie River Focus Watershed Council in the areas of coordination and administration during Fiscal Year 1998. Coordination and administration consists of tasks associated with Focus Watershed Council staffing, project management, and public outreach.

MODELING THE 1958 LITUYA BAY MEGA-TSUNAMI, II

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Charles L. Mader

2002-01-01

Full Text Available Lituya Bay, Alaska is a T-Shaped bay, 7 miles long and up to 2 miles wide. The two arms at the head of the bay, Gilbert and Crillon Inlets, are part of a trench along the Fairweather Fault. On July 8, 1958, an 7.5 Magnitude earthquake occurred along the Fairweather fault with an epicenter near Lituya Bay.A mega-tsunami wave was generated that washed out trees to a maximum altitude of 520 meters at the entrance of Gilbert Inlet. Much of the rest of the shoreline of the Bay was denuded by the tsunami from 30 to 200 meters altitude.In the previous study it was determined that if the 520 meter high run-up was 50 to 100 meters thick, the observed inundation in the rest of Lituya Bay could be numerically reproduced. It was also concluded that further studies would require full Navier-Stokes modeling similar to those required for asteroid generated tsunami waves.During the Summer of 2000, Hermann Fritz conducted experiments that reproduced the Lituya Bay 1958 event. The laboratory experiments indicated that the 1958 Lituya Bay 524 meter run-up on the spur ridge of Gilbert Inlet could be caused by a landslide impact.The Lituya Bay impact landslide generated tsunami was modeled with the full Navier- Stokes AMR Eulerian compressible hydrodynamic code called SAGE with includes the effect of gravity.

Radionuclides in sediments from Port Phillip Bay, Australia

International Nuclear Information System (INIS)

Smith, J.D.; Tinker, R.A.; Towler, P.H.

1998-01-01

Full text: Sediment cores were collected from two sites in Port Phillip Bay, Australia, in 1994 and 1995. The concentration of 210 Pb and parameters including water content were measured. The sites chosen were near the centre of the bay where fine sediment accumulates, and towards the northern end of the bay closer to the mouth of the Yarra River. The mid-bay sediment had a high water content (about 1.8 g water per g dry sediment) and a supported 210 Pb activity of about 22 mBq per g of dry sediment. The sediments from further north in the bay were more consolidated, with a lower water content (about 0.6 g water per g dry sediment), and had a supported 210 Pb activity of about 6 mBq per g of dry sediment. Unsupported 210 Pb occurred to depths of about 10 cm in the mid-bay sediment and about 20 cm in sediment from further north in the bay. Models incorporating the water and 210 Pb contents of the sediments were used to calculate possible rates of sediment accumulation and mixing. The distribution of other radionuclides was used as an aid in understanding the sediment behaviour in Port Phillip Bay

A review of theoretical frameworks applicable for designing agricultural watershed restoration projects

Science.gov (United States)

Agricultural watershed restoration is the process of assisting the recovery of ecosystem structure and/or function within watersheds that have been degraded and damaged by agriculture. Unfortunately, agricultural watershed restoration is the rare exception within the Midwestern United States despit...

Redistribution of cesium-137 in southeastern watersheds

International Nuclear Information System (INIS)

McHenry, J.R.; Ritchie, J.C.

1975-01-01

Sediment samples from 14 southeastern agricultural reservoirs and surface samples from representative soils from the contributing water shed areas were analyzed for 137 Cs. The concentrations of 137 Cs measured reflect the nature of the watershed, its cover, its use, and man's activities. Since the redistribution of 137 Cs was assumed to result from soil erosion, recent erosion rates can be calculated from the measured 137 Cs accumulations in sediments and from the decreases in the 137 Cs calculated to have been deposited on upland soils. Measured concentrations of 137 Cs ranged from 14 to 158 nCi/m 2 in surface soils. As much as 525 nCi/m 2 of 137 Cs was measured in the deposited sediment profile. Watershed budgets for 137 Cs were calculated for three representative watersheds using available sediment survey information and the measured 137 Cs concentrations

Morphometric analysis of sub-watershed in parts of Western Ghats, South India using ASTER DEM

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Evangelin Ramani Sujatha

2015-05-01

Full Text Available Morphometric analysis is a key to understand the hydrological process and hence is a prerequisite for the assessment of hydrological characteristics of surface water basin. Morphometric analysis to determine the drainage characteristics of Palar sub-watershed, a part of Shanmukha watershed in the Amaravati sub-catchment is done using Advanced Space-borne Thermal Emission and Reflection Global Digital Elevation Model (ASTER GDEM data, and is supplemented with topographical maps in geographical information systems platform. This study uses ASTER GDEM data to extract morphometric features of a mountain stream at micro-watershed level. The sub-watershed is divided into six micro-watersheds. The sub-watershed includes a sixth-order stream. Lower stream orders, in particular first-order streams, dominate the sub-watershed. Development of stream segments is controlled by slope and local relief. Drainage pattern of the sub-watershed and micro-watersheds is dendritic in general. The mean bifurcation ratio of the sub-watershed is 3.69 but its variation between the various stream orders suggests structural control in the development of stream network. The shape factors reveal the elongation of the sub-watershed and micro-watersheds.The relief ratio reveals the high discharge capability of the sub-watershed and meagre groundwater potential. This study is a useful tool for planning strategies in control of soil erosion and soil conservation.

Soil erosion and sediment production on watershed landscapes: Processes and control

Science.gov (United States)

Peter F. Ffolliott; Kenneth N. Brooks; Daniel G. Neary; Roberto Pizarro Tapia; Pablo Garcia-Chevesich

2013-01-01

Losses of the soil resources from otherwise productive and well functioning watersheds is often a recurring problem confronting hydrologists and watershed managers. These losses of soil have both on-site and off-site effects on the watershed impacted. In addition to the loss of inherent soil resources through erosion processes, on-site effects can include the breakdown...

What have we learned, and what is new in watershed science?

Science.gov (United States)

Robert R. Ziemer; Leslie M. Reid

1997-01-01

Abstract - Important new lessons are not in technical details, but in how to scale up the details to apply to large watersheds and landscapes. Nearly three years of experience with the Northwest Forest Plan have revealed some major new challenges in the fields of watershed science. In particular, managers and resource specialists engaged in watershed analysis...

Simulation of rain in the watershed Ghezala by KINEROS 2 model

International Nuclear Information System (INIS)

Marghmi, Afef

2010-01-01

The objective of this study is modeling runoff by hydrological, distributed physically based Model, KINEROS2. This model has allowed after calibration to analyze and simulate the hydrological behavior of the watershed Ghezala .The Watershed Ghezala is located in north of Tunisia, in the governorate of Bizerte. It belongs to the bioclimatic mild winter. It covers an area of 4723h, at this watershed; the dominating slop is between 8and 15 pour cent which covers the almost area of the watershed. Dominant type of soil is Calcareous brown guy covering almost 54 pour cent of its total area; Land cover is characterized by the dominance of grain covering 73 pour cent of watershed area. KINEROS2 requires the division of the watershed into plain and channels cascading from upstream to downstream taking into consideration of flow, the geology and land cover of the watershed. During the calibration observed and simulated hydrographs, it must be based on the more sensitive parameters of the model: K (saturated hydraulic conductivity) G (net effective capillary conductivity) and n (parameter Mannig). The calibration's result shows that the error does not exceed, 1pour cent for liquid peak flows of flood hydrographs observed and simulated, 17pour cent for the volume of raw observed and simulated. Thus, the analysis of the hydrological behavior of the watershed studied through the hydrological response to a solicitation (intensity of rain: rain), simulates flood by applying the KINEROS2 model and observing the quantity of water flowing at the outflow of the system (flood hydrograph or rainfall).

Storytelling to support watershed research on emerging issues

Science.gov (United States)

Phillip Hellman

2016-01-01

Projections of budget deficits by the Congressional Budget Office imply ever-increasing pressure on federal spending for all purposes, including long-term watershed research. This presentation will argue that, since federal funding is ultimately a political decision, those responsible for maintaining long-term watershed research programs should not try to provide ...

Trout Creek, Oregon Watershed Assessment; Findings, Condition Evaluation and Action Opportunities, 2002 Technical Report.

Energy Technology Data Exchange (ETDEWEB)

Runyon, John

2002-08-01

The purpose of the assessment is to characterize historical and current watershed conditions in the Trout Creek Watershed. Information from the assessment is used to evaluate opportunities for improvements in watershed conditions, with particular reference to improvements in the aquatic environment. Existing information was used, to the extent practicable, to complete this work. The assessment will aid the Trout Creek Watershed Council in identifying opportunities and priorities for watershed restoration projects.

Hydrologic response and watershed sensitivity to climate warming in California's Sierra Nevada.

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Sarah E Null

Full Text Available This study focuses on the differential hydrologic response of individual watersheds to climate warming within the Sierra Nevada mountain region of California. We describe climate warming models for 15 west-slope Sierra Nevada watersheds in California under unimpaired conditions using WEAP21, a weekly one-dimensional rainfall-runoff model. Incremental climate warming alternatives increase air temperature uniformly by 2 degrees, 4 degrees, and 6 degrees C, but leave other climatic variables unchanged from observed values. Results are analyzed for changes in mean annual flow, peak runoff timing, and duration of low flow conditions to highlight which watersheds are most resilient to climate warming within a region, and how individual watersheds may be affected by changes to runoff quantity and timing. Results are compared with current water resources development and ecosystem services in each watershed to gain insight into how regional climate warming may affect water supply, hydropower generation, and montane ecosystems. Overall, watersheds in the northern Sierra Nevada are most vulnerable to decreased mean annual flow, southern-central watersheds are most susceptible to runoff timing changes, and the central portion of the range is most affected by longer periods with low flow conditions. Modeling results suggest the American and Mokelumne Rivers are most vulnerable to all three metrics, and the Kern River is the most resilient, in part from the high elevations of the watershed. Our research seeks to bridge information gaps between climate change modeling and regional management planning, helping to incorporate climate change into the development of regional adaptation strategies for Sierra Nevada watersheds.

Daya bay reactor neutrino experiment

International Nuclear Information System (INIS)

Cao Jun

2010-01-01

Daya Bay Reactor Neutrino Experiment is a large international collaboration experiment under construction. The experiment aims to precisely determine the neutrino mixing angle θ 13 by detecting the neutrinos produced by the Daya Bay Nuclear Power Plant. θ 13 is one of two unknown fundamental parameters in neutrino mixing. Its magnitude is a roadmap of the future neutrino physics, and very likely related to the puzzle of missing antimatter in our universe. The precise measurement has very important physics significance. The detectors of Daya Bay is under construction now. The full operation is expected in 2011. Three years' data taking will reach the designed the precision, to determine sin 2 2θ 13 to better than 0.01. Daya Bay neutrino detector is an underground large nuclear detector of low background, low energy, and high precision. In this paper, the layout of the experiment, the design and fabrication progress of the detectors, and some highlighted nuclear detecting techniques developed in the detector R and D are introduced. (author)

226Ra and 228Ra in the mixing zones of the Pee Dee River-Winyah Bay, Yangtze River and Delaware Bay Estuaries

International Nuclear Information System (INIS)

Elsinger, R.J.; Moore, W.S.

1984-01-01

226 Ra and 228 Ra have non-conservative excess concentrations in the mixing zones of the Pee Dee River-Winyah Bay estuary, the Yangtze River estuary, and the Delaware Bay estuary. Laboratory experiments, using Pee Dee River sediment, indicate desorption of 226 Ra to increase with increasing salinities up to 20 per mille. In Winyah Bay desorption from river-borne sediments could contribute almost all of the increases for both isotopes. Desorption adds only a portion of the excess 228 Ra measured in the Yangtze River and adjacent Shelf waters and Delaware Bay. In the Yangtze River the mixing zone extends over a considerable portion of the Continental Shelf where 228 Ra is added to the water column by diffusion from bottom sediments, while 226 Ra concentrations decrease from dilution. Diffusion of 228 Ra from bottom sediments in Delaware Bay primarily occurs in the upper part of the bay ( 228 Ra of 0.33 dpm cm -2 year was determined for Delaware Bay. (author)

Characterization and evaluation of controls on post-fire streamflow response across western US watersheds

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S. Saxe

2018-02-01

Full Text Available This research investigates the impact of wildfires on watershed flow regimes, specifically focusing on evaluation of fire events within specified hydroclimatic regions in the western United States, and evaluating the impact of climate and geophysical variables on response. Eighty-two watersheds were identified with at least 10 years of continuous pre-fire daily streamflow records and 5 years of continuous post-fire daily flow records. Percent change in annual runoff ratio, low flows, high flows, peak flows, number of zero flow days, baseflow index, and Richards–Baker flashiness index were calculated for each watershed using pre- and post-fire periods. Independent variables were identified for each watershed and fire event, including topographic, vegetation, climate, burn severity, percent area burned, and soils data. Results show that low flows, high flows, and peak flows increase in the first 2 years following a wildfire and decrease over time. Relative response was used to scale response variables with the respective percent area of watershed burned in order to compare regional differences in watershed response. To account for variability in precipitation events, runoff ratio was used to compare runoff directly to PRISM precipitation estimates. To account for regional differences in climate patterns, watersheds were divided into nine regions, or clusters, through k-means clustering using climate data, and regression models were produced for watersheds grouped by total area burned. Watersheds in Cluster 9 (eastern California, western Nevada, Oregon demonstrate a small negative response to observed flow regimes after fire. Cluster 8 watersheds (coastal California display the greatest flow responses, typically within the first year following wildfire. Most other watersheds show a positive mean relative response. In addition, simple regression models show low correlation between percent watershed burned and streamflow response, implying that

Allegheny County Watershed Boundaries

Data.gov (United States)

Allegheny County / City of Pittsburgh / Western PA Regional Data Center — This dataset demarcates the 52 isolated sub-Watersheds of Allegheny County that drain to single point on the main stem rivers. Created by 3 Rivers 2nd Nature based...

Assessing critical source areas in watersheds for conservation buffer planning and riparian restoration.

Science.gov (United States)

Qiu, Zeyuan

2009-11-01

A science-based geographic information system (GIS) approach is presented to target critical source areas in watersheds for conservation buffer placement. Critical source areas are the intersection of hydrologically sensitive areas and pollutant source areas in watersheds. Hydrologically sensitive areas are areas that actively generate runoff in the watershed and are derived using a modified topographic index approach based on variable source area hydrology. Pollutant source areas are the areas in watersheds that are actively and intensively used for such activities as agricultural production. The method is applied to the Neshanic River watershed in Hunterdon County, New Jersey. The capacity of the topographic index in predicting the spatial pattern of runoff generation and the runoff contribution to stream flow in the watershed is evaluated. A simple cost-effectiveness assessment is conducted to compare the conservation buffer placement scenario based on this GIS method to conventional riparian buffer scenarios for placing conservation buffers in agricultural lands in the watershed. The results show that the topographic index reasonably predicts the runoff generation in the watershed. The GIS-based conservation buffer scenario appears to be more cost-effective than the conventional riparian buffer scenarios.

The Neoglacial landscape and human history of Glacier Bay, Glacier Bay National Park and Preserve, southeast Alaska, USA

Science.gov (United States)

Connor, C.; Streveler, G.; Post, A.; Monteith, D.; Howell, W.

2009-01-01

The Neoglacial landscape of the Huna Tlingit homeland in Glacier Bay is recreated through new interpretations of the lower Bay's fjordal geomorphology, late Quaternary geology and its ethnographic landscape. Geological interpretation is enhanced by 38 radiocarbon dates compiled from published and unpublished sources, as well as 15 newly dated samples. Neoglacial changes in ice positions, outwash and lake extents are reconstructed for c. 5500?????"200 cal. yr ago, and portrayed as a set of three landscapes at 1600?????"1000, 500?????"300 and 300?????"200 cal. yr ago. This history reveals episodic ice advance towards the Bay mouth, transforming it from a fjordal seascape into a terrestrial environment dominated by glacier outwash sediments and ice-marginal lake features. This extensive outwash plain was building in lower Glacier Bay by at least 1600 cal. yr ago, and had filled the lower bay by 500 cal. yr ago. The geologic landscape evokes the human-described landscape found in the ethnographic literature. Neoglacial climate and landscape dynamism created difficult but endurable environmental conditions for the Huna Tlingit people living there. Choosing to cope with environmental hardship was perhaps preferable to the more severely deteriorating conditions outside of the Bay as well as conflicts with competing groups. The central portion of the outwash plain persisted until it was overridden by ice moving into Icy Strait between AD 1724?????"1794. This final ice advance was very abrupt after a prolonged still-stand, evicting the Huna Tlingit from their Glacier Bay homeland. ?? 2009 SAGE Publications.

Organic Matter Remineralization Predominates Phosphorus Cycling in the Mid-Bay Sediments in the Chesapeake Bay