A5025564264- Soil and Water Nutrient Dynamics
- Hydrology and Watershed Management Studies
- Geological and Geochemical Analysis
- Paleontology and Stratigraphy of Fossils
- Geology and Paleoclimatology Research
- Water Quality and Resources Studies
- Geological formations and processes
- Water Quality and Pollution Assessment
- Urban, Neighborhood, and Segregation Studies
- Geochemistry and Geologic Mapping
- Groundwater and Isotope Geochemistry
- earthquake and tectonic studies
- Fish Ecology and Management Studies
- Marine and coastal ecosystems
- Flood Risk Assessment and Management
- Water resources management and optimization
- Catalytic Processes in Materials Science
- Disaster Management and Resilience
- Hydrocarbon exploration and reservoir analysis
- Advanced Combustion Engine Technologies
- Housing Market and Economics
- Industrial Gas Emission Control
- Geological and Geophysical Studies
- Pleistocene-Era Hominins and Archaeology
- Water-Energy-Food Nexus Studies
United States Geological Survey
2012-2024
University of Exeter
2023
United States Department of the Interior
2023
Jeremy Benn Associates (United Kingdom)
2021
Monterey County Health Department
2017
British Geological Survey
1998-2014
University of St Andrews
2013
Instituto Geológico y Minero de España
2010
Central Queensland University
2001-2009
Imperial College London
1993-2006
Some of the characteristics that complicate analysis water quality time series are non‐normal distributions, seasonality, flow relatedness, missing values, values below limit detection, and serial correlation. Presented here techniques suitable in face complications listed above for exploratory monthly data monotonie trends. The first procedure described is a nonparametric test trend applicable to sets with or reported as ‘less than’: seasonal Kendall test. Under realistic stochastic...
Seasonal hypoxia in the northern Gulf of Mexico has been linked to increased nitrogen fluxes from Mississippi and Atchafalaya River Basins, though recent evidence shows that phosphorus also influences productivity Gulf. We developed a spatially explicit structurally detailed SPARROW water-quality model reveals important differences sources transport processes control (N) (P) delivery Our simulations indicate agricultural watersheds contribute more than 70% delivered N P. However, corn...
We describe a method for using spatially referenced regressions of contaminant transport on watershed attributes (SPARROW) in regional water‐quality assessment. The is designed to reduce the problems data interpretation caused by sparse sampling, network bias, and basin heterogeneity. regression equation relates measured rates streams descriptors pollution sources land‐surface stream‐channel characteristics. Regression models total phosphorus (TP) nitrogen (TN) are constructed region defined...
Knowledge of headwater influences on the water-quality and flow conditions downstream waters is essential to water-resource management at all governmental levels; this includes recent court decisions jurisdiction Federal Clean Water Act (CWA) over upland areas that contribute larger water bodies. We review current watershed research use a model investigate receiving waters. Our evaluations demonstrate intrinsic connections headwaters landscape processes through their influence supply,...
One result of increased scientific and public interest in water quality over the past few decades has been gradual accumulation reliable long‐term data records an examining these for trends. This paper summarizes examines some major issues choices involved detecting estimating magnitude temporal trends measures stream quality. The first issue is type trend hypothesis to examine: step versus monotonic trend. second relates general category statistical methods employ: parametric nonparametric....
Water-quality records from two nationwide sampling networks now permit nationally consistent analysis of long-term water-quality trends at more than 300 locations on major U.S. rivers. Observed in 24 measures water quality for the period 1974 to 1981 provide new insight into changes stream that occurred during a time both terrestrial and atmospheric influences surface waters. Particularly noteworthy are widespread decreases fecal bacteria lead concentrations increases nitrate, chloride,...
A better understanding is needed of how hydrological and biogeochemical processes control dissolved organic carbon (DOC) concentrations matter (DOM) composition from headwaters downstream to large rivers. We examined a DOM dataset the National Water Information System US Geological Survey, which represents approximately 100 000 measurements DOC concentration at many sites along rivers across United States. Application quantile regression revealed tendency towards spatial temporal...
Determining natural background concentrations of nutrients in watersheds the developed world has been hampered by a lack pristine sampling sites covering range climatic conditions and basin sizes. Using data from 63 minimally impacted U.S. Geological Survey reference basins, we empirical models yield total nitrogen (TN) phosphorus (TP) small as functions annual runoff, size, atmospheric deposition rate, region-specific factors. We applied previously estimated in-stream loss rates to yields...
A set of statistical methods particularly well suited for evaluating time series monthly water-quality data are presented.The Seasonal Kendall Test trend is defined.It a nonparametric test based on the differences between observations in same month different years.Under realistic stochastic processes (exhibiting seasonality, skewness, and serial correlation) it robust by comparison with parametric alternative regression.The Slope Estimator, measure magnitude, closely related to Test.It an...
A catalog of the various political expertise and schema measures in use reveals little consensus among researchers basis for comparison across research programs. To examine varieties their utilities information processing, virtually entire battery available was given to a sample Pittsburgh voters, who then read newspaper articles on issues current local interest. Confirmatory factor analysis indicated cluster knowledge, operationalized as (a) accurate consensual knowledge about liberals'...
For additional information, contact: National Water-Quality Assessment ProgramU.S. Geological Survey413 Center12201 Sunrise Valley DriveReston, Virginia 20192https://water.usgs.gov/nawqa/ SPARROW (SPAtially Referenced Regressions On Watershed attributes) is a watershed modeling technique for relating water-quality measurements made at network of monitoring stations to attributes the watersheds containing stations. The core model consists nonlinear regression equation describing...
Abstract Net ecosystem production (NEP) and the overall organic carbon budget for estuaries along East Coast of United States are estimated. We focus on open estuarine waters, excluding fringing wetlands. developed empirical models relating NEP to loading ratios dissolved inorganic nitrogen total carbon, burial in sediment water residence time input across landward boundary. Output from a data‐constrained quality model was used estimate inputs boundary, including fluvial tidal‐wetland...
Estimates of nitrogen and phosphorus fertilizer use were made for counties in the United States period 1945 to 1985. County estimates obtained through disaggregation state-level proportion amount state fertilized acreage reported exist counties. Numerical values by county are not presented text this report because size data file, but available machine-readable form upon request. Graphical summaries national, state, briefly describe spatial temporal variability that data.
Abstract State planning mandates have been used to achieve state policy objectives through the local process. Recent research has shown that plan quality is higher both in states with for and those where authority review plans enforce greater. Florida generally considered be among strongest of mandate states. We examine extent which eighteen communities comply about coastal storm hazards. Compliance requirements highly variable—greater some than others; within categories, vary substantially...
Author(s): Wood, CP; Mc donell, VG; Smith, RA; Samuelsen, GS | Abstract: A surrogate fuel comprised of 14 pure hydrocarbons is formulated based on the distillation curve and compound class composition a petroleum-derived JP-4. The goal to establish controlled for modeling, study property chemical effects in combustion JP-4 fuels. Spatially resolved interferometric measurements droplet size velocity are obtained compared both petroleum nonreacting spray chamber. Measurements also high...
Moore, Richard B., Craig M. Johnston, A. Smith, and Bryan Milstead, 2011. Source Delivery of Nutrients to Receiving Waters in the Northeastern Mid-Atlantic Regions United States. Journal American Water Resources Association (JAWRA) 47(5):965-990. DOI: 10.1111/j.1752-1688.2011.00582.x Abstract: This study investigates nutrient sources transport receiving waters, order provide spatially detailed information aid water-resources managers concerned with eutrophication management strategies....
We estimated trends in concentrations of total phosphorus (TP) and nitrogen (TN) the related change probabilities trophic conditions from 1975 to 1994 at 250 nationally representative riverine monitoring locations U.S. with drainage areas larger than about 1,000 km 2 . Statistically significant (p < 0.05) declines were detected TP TN 44% 37% sites, increases 3% 9% respectively. used a statistical model assess changes probable trophic‐state classification sites after adjusting for...
The statistical watershed model SPARROW (SPAtially Referenced Regression On Watershed attributes) was used to estimate the sources and transport of total phosphorus (TP) in surface waters United States. We calibrated using stream measurements TP from 336 watersheds mixed land use spatial data on topography, soils, hydrography, (agriculture, forest, shrub/grass, urban). explained 87% variability log transformed flux (kg yr(-1)). Predictions yield ha(-1) yr(-1)) were typically within 45%...
The ‘older’ granites of Perthshire were emplaced in the Dalradian between second and third deformation episodes a Caledonian D1–D4 sequence. Pankhurst & Pidgeon (1976) have furnished zircon U-Pb Rb/Sr whole-rock age (514 +6/–7 Ma) for emplacement Ben Vuirich granite which provides minimum D2 event. A somewhat younger isochron (491 ± 15 obtained from Dunfallandy Hill may date D3. Migmatisation occurred D2–D3 interval is, by inference, also dated. Dl D2, deform Arenig rocks Southern...
Research Article| March 01, 2010 THE GEOLOGY AND GEOCHEMISTRY OF EAST AFRICAN OROGEN IN NORTHEASTERN MOZAMBIQUE R. BOYD; BOYD Geological Survey of Norway, N-7491 Trondheim, email: Rognvald.Boyd@ngu.no; Oystein.Nordgulen@ngu.no Search for other works by this author on: GSW Google Scholar Ø. NORDGULEN; NORDGULEN R.J. THOMAS; THOMAS British Survey, Keyworth, United Kingdom, bthomas@bgs.ac.uk B. BINGEN; BINGEN Bernard.Bingen@ngu.no; Terje.Bjerkgard@ngu.no; Tor.Grenne@ngu.no;...
Adaptation strategies to ameliorate the impacts of climate change are increasing in scale and scope around world, with interventions becoming a part daily life for many people. Though implications health wellbeing well documented, date, adaptations largely evaluated by financial cost their effectiveness reducing risk. Looking across different forms adaptation floods, we use existing literature develop typology key domains impact arising from that likely shape wellbeing. We suggest this can...
Abstract Freshwater salinization is a growing global concern impacting human and ecosystem needs with impacts to water availability for ecological uses. In the Upper Colorado River Basin (UCRB), dissolved solids in streams compound ongoing supply challenges further limit cause economic damages. Much effort has been dedicated understanding solid sources, transport, management region, yet temporal variability loading from key sources such as irrigated lands influence of climate on remains...