Subsurface drainage erodes forested granitic terrane

Treesearch

Philip Durgin

1984-01-01

Abstract - Solution and landsliding, the dominant erosion processes in undisturbed forested mountainous watersheds, are both influenced by subsurface drainage. Biological processes that generate organic acids accelerate loss of dissolved solids by promoting the dissolution of primary minerals in granitic rock. These organic acids can also disperse the secondary...

Profiling USGA putting greens using GPR

USDA-ARS?s Scientific Manuscript database

All USGA-specification putting greens require a subsurface drainage system. A typical subsurface installation is a herringbone pattern of buried 100-mm dia. PVC drainage pipes, designed such that the central main line is placed along the line of maximum slope. Laterals are spaced no more than 5 m, r...

Antibiotic resistance and community analysis of surface and subsurface drainage waters in the South Fork Iowa River watershed

USDA-ARS?s Scientific Manuscript database

The Midwest is a center for swine production leading to application of swine manure onto lands that have artificial subsurface drainage. Previous reports have indicated elevated levels of antibiotic resistance genes (ARGs) in surface water and groundwater around confined animal feeding operations w...

Antibiotic resistance and community analysis of surface and subsurface drainage waters in the South Fork Iowa River watershed

USDA-ARS?s Scientific Manuscript database

The Midwest is a center for swine production leading to application of swine manure onto lands that have artificial subsurface drainage. Previous reports have indicated elevated levels of antibiotic resistance genes (ARGs) in surface water and groundwater around confined animal feeding operations wh...

Corn stover harvest increases herbicide movement to subsurface drains: RZWQM simulations

USGS Publications Warehouse

Shipitalo, Martin J.; Malone, Robert W.; Ma, Liwang; Nolan, Bernard T.; Kanwar, Rameshwar S.; Shaner, Dale L.; Pederson, Carl H.

2016-01-01

BACKGROUND Crop residue removal for bioenergy production can alter soil hydrologic properties and the movement of agrochemicals to subsurface drains. The Root Zone Water Quality Model (RZWQM), previously calibrated using measured flow and atrazine concentrations in drainage from a 0.4 ha chisel-tilled plot, was used to investigate effects of 50 and 100% corn (Zea mays L.) stover harvest and the accompanying reductions in soil crust hydraulic conductivity and total macroporosity on transport of atrazine, metolachlor, and metolachlor oxanilic acid (OXA). RESULTS The model accurately simulated field-measured metolachlor transport in drainage. A 3-yr simulation indicated that 50% residue removal decreased subsurface drainage by 31% and increased atrazine and metolachlor transport in drainage 4 to 5-fold when surface crust conductivity and macroporosity were reduced by 25%. Based on its measured sorption coefficient, ~ 2-fold reductions in OXA losses were simulated with residue removal. CONCLUSION RZWQM indicated that if corn stover harvest reduces crust conductivity and soil macroporosity, losses of atrazine and metolachlor in subsurface drainage will increase due to reduced sorption related to more water moving through fewer macropores. Losses of the metolachlor degradation product OXA will decrease due to the more rapid movement of the parent compound into the soil.

Reconnecting tile drainage to riparian buffer hydrology for enhanced nitrate removal.

PubMed

Jaynes, D B; Isenhart, T M

2014-03-01

Riparian buffers are a proven practice for removing NO from overland flow and shallow groundwater. However, in landscapes with artificial subsurface (tile) drainage, most of the subsurface flow leaving fields is passed through the buffers in drainage pipes, leaving little opportunity for NO removal. We investigated the feasibility of re-routing a fraction of field tile drainage as subsurface flow through a riparian buffer for increasing NO removal. We intercepted an existing field tile outlet draining a 10.1-ha area of a row-cropped field in central Iowa and re-routed a fraction of the discharge as subsurface flow along 335 m of an existing riparian buffer. Tile drainage from the field was infiltrated through a perforated pipe installed 75 cm below the surface by maintaining a constant head in the pipe at a control box installed in-line with the existing field outlet. During 2 yr, >18,000 m (55%) of the total flow from the tile outlet was redirected as infiltration within the riparian buffer. The redirected water seeped through the 60-m-wide buffer, raising the water table approximately 35 cm. The redirected tile flow contained 228 kg of NO. On the basis of the strong decrease in NO concentrations within the shallow groundwater across the buffer, we hypothesize that the NO did not enter the stream but was removed within the buffer by plant uptake, microbial immobilization, or denitrification. Redirecting tile drainage as subsurface flow through a riparian buffer increased its NO removal benefit and is a promising management practice to improve surface water quality within tile-drained landscapes. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Weather, landscape, and management effects on nitrate and soluble phosphorus concentrations in subsurface drainage discharge in the western Lake Erie basin

USDA-ARS?s Scientific Manuscript database

Subsurface drainage, while an important and necessary agricultural production practice in the Midwest, contributes nitrate (NO3) and soluble phosphorus (P) to surface waters. Eutrophication (i.e., excessive enrichment of waters by NO3 and soluble P) supports harmful algal blooms (HABs) in receiving ...

Effect of replacing surface inlets with blind or gravel inlets on sediment and phosphorus subsurface drainage losses

USDA-ARS?s Scientific Manuscript database

Open surface inlets that connect to subsurface tile drainage systems provide a direct pathway for sediment, nutrients, and agrochemicals to surface waters. This study was conducted to determine whether modifying open inlets by burying them in gravel capped with 30 cm of sandy clay loam soil or in ve...

Subsurface Agricultural Irrigation Drainage: The Need for Regulation

Treesearch

A. Dennis Lemly

1993-01-01

Subsurface drainage resulting from irrigated agriculture is a toxic threat to fish and wildlife resources throughout the western United States. Studies by the U.S. Department of the Interior show that migratory waterfowl have been poisoned by drainwater contaminants on at least six national wildlife refuges. Allowing this poisoning to continue is a violation of the...

Subsurface agricultural irrigation drainage: the need for regulation.

PubMed

Lemly, A D

1993-04-01

Subsurface drainage resulting from irrigated agriculture is a toxic threat to fish and wildlife resources throughout the western United States. Studies by the U.S. Department of the Interior show that migratory waterfowl have been poisoned by drainwater contaminants on at least six national wildlife refuges. Allowing this poisoning to continue is a violation of the Migratory Bird Treaty Act under U.S. Federal law. Critical wetlands and waterfowl populations are threatened in both the Pacific and Central flyways. The public is also at risk and health warnings have been issued in some locations. Subsurface irrigation drainage is a complex effluent containing toxic concentrations of trace elements, salts, and nitrogenous compounds. Some of the contaminants are classified by the U.S. Environmental Protection Agency (EPA) as priority pollutants and they can be present in concentrations that exceed EPA's criteria for toxic waste. The on-farm drainage systems used to collect and transport this wastewater provide point-source identification as well as a mechanism for toxics control through the National Pollutant Discharge Elimination System (NPDES) permit process. A four-step approach is presented for dealing with irrigation drainage in an environmentally sound manner. This regulatory strategy is very similar to those commonly used for industrial discharges and includes site evaluation, contaminant reduction through NPDES, and compliance monitoring. The EPA must recognize subsurface irrigation drainage as a specific class of pollution subject to regulation under the NPDES process. Active involvement by EPA is necessary to ensure that adequate controls on this wastewater are implemented.

Quantification of mine-drainage inflows to Little Cottonwood Creek, Utah, using a tracer-injection and synoptic-sampling study

USGS Publications Warehouse

Kimball, B.; Runkel, R.; Gerner, L.

2001-01-01

Historic mining in Little Cottonwood Canyon in Utah has left behind many mine drainage tunnels that discharge water to Little Cottonwood Creek. To quantify the major sources of mine drainage to the stream, synoptic sampling was conducted during a tracer injection under low flow conditions (September 1998). There were distinct increases in discharge downstream from mine drainage and major tributary inflows that represented the total surface and subsurface contributions. The chemistry of stream water determined from synoptic sampling was controlled by the weathering of carbonate rocks and mine drainage inflows. Buffering by carbonate rocks maintained a high pH throughout the study reach. Most of the metal loading was from four surface-water inflows and three subsurface inflows. The main subsurface inflow was from a mine pool in the Wasatch Tunnel. Natural attenuation of all the metals resulted in the formation of colloidal solids, sorption of some metals, and accumulation onto the streambed. The deposition on the streambed could contribute to chronic toxicity for aquatic organisms. Information from the study will help to make decisions about environmental restoration.

Subsurface drainage volume reduction with drainage water management: Case studies in Ohio, USA

USDA-ARS?s Scientific Manuscript database

One of the main contributors to poor water quality in the Mississippi River and aeral increase in the hypoxic zone in the Gulf of Mexico is intensive drainage of the cropland within the watershed. Controlled drainage has been demonstrated as an approach to curb totla drainage outflow and nutrient di...

PASSIVE TREATMENT OF ACID ROCK DRAINAGE FROM A SUBSURFACE MINE

EPA Science Inventory

Acidic, metal-contaminated drainages are a critical problem facing many areas of the world. Acid rock drainage results when metal sulfide minerals, particularly pyrite, are oxidized by exposure to oxygen and water. The deleterious effects of these drainages on receiving streams a...

Cover cropping to reduce nitrate loss through subsurface drainage in the northern U.S. corn belt.

PubMed

Strock, J S; Porter, P M; Russelle, M P

2004-01-01

Despite the use of best management practices for nitrogen (N) application rate and timing, significant losses of nitrate nitrogen (NO3(-)-N) in drainage discharge continue to occur from row crop cropping systems. Our objective was to determine whether a autumn-seeded winter rye (Secale cereale L.) cover crop following corn (Zea mays L.) would reduce NO3(-)-N losses through subsurface tile drainage in a corn-soybean [Glycine mar (L.) Merr.] cropping system in the northern Corn Belt (USA) in a moderately well-drained soil. Both phases of the corn-soybean rotation, with and without the winter rye cover crop following corn, were established in 1998 in a Normania clay loam (fine-loamy, mixed, mesic Aquic Haplustoll) soil at Lamberton, MN. Cover cropping did not affect subsequent soybean yield, but reduced drainage discharge, flow-weighted mean nitrate concentration (FWMNC), and NO3(-)-N loss relative to winter fallow, although the magnitude of the effect varied considerably with annual precipitation. Three-year average drainage discharge was lower with a winter rye cover crop than without (p = 0.06). Over three years, subsurface tile-drainage discharge was reduced 11% and NO3(-)-N loss was reduced 13% for a corn-soybean cropping system with a rye cover crop following corn than with no rye cover crop. We estimate that establishment of a winter rye cover crop after corn will be successful in one of four years in southwestern Minnesota. Cover cropping with rye has the potential to be an effective management tool for reducing NO3(-)-N loss from subsurface drainage discharge despite challenges to establishment and spring growth in the north-central USA.

Subsurface recharge to the Tesuque aquifer system from selected drainage basins along the western side of the Sangre de Cristo Mountains near Santa Fe, New Mexico

USGS Publications Warehouse

Wasiolek, Maryann

1995-01-01

Water budgets developed for basins of five streams draining the western side of the Sangre de Cristo Mountains in northern New Mexico indicate that subsurface inflow along the mountain front is recharging the Tesuque aquifer system of the Espanola Basin. Approximately 14,700 acre-feet of water per year, or 12.7 percent of average annual precipitation over the mountains, is calculated to leave the mountain block and enter the basin as subsurface recharge from the drainage basins of the Rio Nambe, Rio en Medio, Tesuque Creek, Little Tesuque Creek, and Santa Fe River. About 5,520 acre- feet per year, or about 12 percent of average annual precipitation, is calculated to enter from the Rio Nambe drainage basin; about 1,710 acre- feet per year, or about 15 percent of average annual precipitation, is calculated to enter from the Rio en Medio drainage basin; about 1,530 acre- feet, or about 10 percent of average annual precipi- tation, is calculated to enter from the Tesuque Creek drainage basin; about 1,790 acre-feet, or about 19 percent of average annual precipitation, is calculated to enter from the Little Tesuque Creek drainage basin; and about 4,170 acre-feet per year, or about 12 percent average annual precipitation, is calculated to enter from the Santa Fe River drainage basin. Calculated subsurface recharge values were used to define maximum fluxes permitted along the specified-flux boundary defining the mountain front of the Sangre De Cristo Mountains in a numerical computer model of the Tesuque aquifer system near Santa Fe, New Mexico.

Assessment of Nitrate-N Load in Subsurface Drainage Water from the Agricultural Fields in the Fergana Valley, Uzbekistan

NASA Astrophysics Data System (ADS)

Kenjabaev, S.; Forkutsa, I.; Dukhovny, V.; Frede, H. G.

2012-04-01

Leaching of nitrate-N (NO3-) from irrigated agricultural land and water contamination have become a worldwide concern. This study was conducted to investigate amount of nitrate-N leached to groundwater and surface water from irrigated cotton, winter wheat and maize fields in the Fergana Valley (Uzbekistan). Therefore at two sites ("Akbarabad" and "Azizbek") equipped with closed horizontal drainage system during 2010-2011 vegetation seasons we monitored water flow, nutrient concentrations and salinity at surface and subsurface drains, at irrigation canals and groundwater. We also applied stable isotopes (δ2H and δ18O) method in order to investigate the source of drainage water runoff. Discussed are results of 2010. Farmers fertilized cotton fields with ammonium nitrate of 350-450 kg ha-1 in "Akbarabad" and 700 kg ha-1 in "Azizbek" sites. In winter wheat and maize fields (in "Akbarabad") about 500 kg ha-1 of ammonium nitrate were applied. Cotton fields were irrigated with 2700 m3 ha-1 ("Akbarabad") and 3500 m3 ha-1 ("Azizbek"). In winter wheat and maize fields applied irrigation water amounted to 3900 m3 ha-1 and 723 m3 ha-1, respectively. Frequent groundwater and subsurface drainage water sampling revealed that nitrate leaching occurred mostly during and right after the irrigation events. The estimated average nitrate-N concentration in subsurface drainage water in "Akbarabad" was slightly higher (9 mg l-1) than in "Azizbek" (8 mg l-1). During July-November (2010), in average, nitrate-N losses through subsurface drainage amounted to 24 kg ha-1 in "Akbarabad" and 18 kg ha-1 in "Azizbek". The salinity of drainage water at both sites was similar and varied between 2.3-2.7 dS m-1. Preliminary results of isotope signals of studied water (precipitation, drainage, irrigation and ground water) indicate that the source of drainage water runoff comes from the irrigation water, while the contribution of rainfall is negligible. It is planned to run simulations with DRAINMOD model for further investigation of water and N balances of the selected sites. Developed recommendations for farmers on optimum irrigation water amounts and N fertilization will allow reducing environmental risks in agricultural lands of the Fergana Valley.

Exploring Agricultural Drainage's Influence on Wetland and Watershed Connectivity

EPA Science Inventory

Artificial agricultural drainage (i.e. surface ditches or subsurface tile) is an important agricultural management tool. Artificial drainage allows for timely fieldwork and adequate root aeration, resulting in greater crop yields for farmers. This practice is widespread throughou...

Nitrate and phosphate removal from agricultural subsurface drainage using laboratory woodchip bioreactors and recycled steel byproduct filters.

PubMed

Hua, Guanghui; Salo, Morgan W; Schmit, Christopher G; Hay, Christopher H

2016-10-01

Woodchip bioreactors have been increasingly used as an edge-of-field treatment technology to reduce the nitrate loadings to surface waters from agricultural subsurface drainage. Recent studies have shown that subsurface drainage can also contribute substantially to the loss of phosphate from agricultural soils. The objective of this study was to investigate nitrate and phosphate removal in subsurface drainage using laboratory woodchip bioreactors and recycled steel byproduct filters. The woodchip bioreactor demonstrated average nitrate removal efficiencies of 53.5-100% and removal rates of 10.1-21.6 g N/m(3)/d for an influent concentration of 20 mg N/L and hydraulic retention times (HRTs) of 6-24 h. When the influent nitrate concentration increased to 50 mg N/L, the bioreactor nitrate removal efficiency and rate averaged 75% and 18.9 g N/m(3)/d at an HRT of 24 h. Nitrate removal by the woodchips followed zero-order kinetics with rate constants of 1.42-1.80 mg N/L/h when nitrate was non-limiting. The steel byproduct filter effectively removed phosphate in the bioreactor effluent and the total phosphate adsorption capacity was 3.70 mg P/g under continuous flow conditions. Nitrite accumulation occurred in the woodchip bioreactor and the effluent nitrite concentrations increased with decreasing HRTs and increasing influent nitrate concentrations. The steel byproduct filter efficiently reduced the level of nitrite in the bioreactor effluent. Overall, the results of this study suggest that woodchip denitrification followed by steel byproduct filtration is an effective treatment technology for nitrate and phosphate removal in subsurface drainage. Published by Elsevier Ltd.

Corn stover harvest increases herbicide movement to subsurface drains - Root Zone Water Quality Model simulations.

PubMed

Shipitalo, Martin J; Malone, Robert W; Ma, Liwang; Nolan, Bernard T; Kanwar, Rameshwar S; Shaner, Dale L; Pederson, Carl H

2016-06-01

Crop residue removal for bioenergy production can alter soil hydrologic properties and the movement of agrochemicals to subsurface drains. The Root Zone Water Quality Model (RZWQM), previously calibrated using measured flow and atrazine concentrations in drainage from a 0.4 ha chisel-tilled plot, was used to investigate effects of 50 and 100% corn (Zea mays L.) stover harvest and the accompanying reductions in soil crust hydraulic conductivity and total macroporosity on transport of atrazine, metolachlor and metolachlor oxanilic acid (OXA). The model accurately simulated field-measured metolachlor transport in drainage. A 3 year simulation indicated that 50% residue removal reduced subsurface drainage by 31% and increased atrazine and metolachlor transport in drainage 4-5-fold when surface crust conductivity and macroporosity were reduced by 25%. Based on its measured sorption coefficient, approximately twofold reductions in OXA losses were simulated with residue removal. The RZWQM indicated that, if corn stover harvest reduces crust conductivity and soil macroporosity, losses of atrazine and metolachlor in subsurface drainage will increase owing to reduced sorption related to more water moving through fewer macropores. Losses of the metolachlor degradation product OXA will decrease as a result of the more rapid movement of the parent compound into the soil. Published 2015. This article is a U.S. Government work and is in the public domain in the USA. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

Femtosecond laser subsurface scleral treatment in cadaver human sclera and evaluation using two-photon and confocal microscopy

NASA Astrophysics Data System (ADS)

Sun, Hui; Fan, Zhongwei; Yan, Ying; Lian, Fuqiang; Kurtz, Ron; Juhasz, Tibor

2016-03-01

Glaucoma is the second-leading cause of blindness worldwide and is often associated with elevated intraocular pressure (IOP). Partial-thickness drainage channels can be created with femtosecond laser in the translucent sclera for the potential treatment of glaucoma. We demonstrate the creation of partial-thickness subsurface drainage channels with the femtosecond laser in the cadaver human eyeballs and describe the application of two-photon microscopy and confocal microscopy for noninvasive imaging of the femtosecond laser created partial-thickness scleral channels in cadaver human eyes. A femtosecond laser operating at a wavelength of 1700 nm was scanned along a rectangular raster pattern to create the partial thickness subsurface drainage channels in the sclera of cadaver human eyes. Analysis of the dimensions and location of these channels is important in understanding their effects. We describe the application of two-photon microscopy and confocal microscopy for noninvasive imaging of the femtosecond laser created partial-thickness scleral channels in cadaver human eyes. High-resolution images, hundreds of microns deep in the sclera, were obtained to allow determination of the shape and dimension of such partial thickness subsurface scleral channels. Our studies suggest that the confocal and two-photon microscopy can be used to investigate femtosecond-laser created partial-thickness drainage channels in the sclera of cadaver human eyes.

An overview of impact of subsurface drainage project studies on salinity management in developing countries

NASA Astrophysics Data System (ADS)

Tiwari, Priyanka; Goel, Arun

2017-05-01

Subsurface drainage has been used for more than a century to keep water table at a desired level of salinity and waterlogging control. This paper has been focused on the impact assessment of pilot studies in India and some other countries from 1969 to 2014 . This review article may prove quite useful in deciding the installation of subsurface drainage project depending on main design parameters, such as drain depth and drain spacing, installation area and type of used outlet. A number of pilot studies have been taken up in past to solve the problems of soil salinity and waterlogging in India. The general guidelines that arise on the behalf of this review paper are to adapt drain depth >1.2 m and spacing depending on soil texture classification, i.e., 100-150 m for light-textured soils, 50-100 m for medium-textured soils and 30-50 m heavy-textured soils, for better result obtained from the problem areas in Indian soil and climatic conditions. An attempt has been made in the manner of literature survey to highlight the salient features of these studies, and it is hopeful to go a long way in selecting design parameters for subsurface drainage problems in the future with similar soil, water table and climatic conditions.

Comparison of performance of tile drainage routines in SWAT 2009 and 2012 in an extensively tile-drained watershed in Midwest

USDA-ARS?s Scientific Manuscript database

Subsurface tile drainage systems are widely used in agricultural watersheds in the Midwestern U.S. Tile drainage systems enable the Midwest area to become highly productive agricultural lands, but can also create environmental problems, for example nitrate-N contamination associated with drainage w...

Impacts of drainage water management on subsurface drain flow, nitrate concentration, and nitrate loads in Indiana

EPA Science Inventory

Drainage water management is a conservation practice that has the potential to reduce drainage outflow and nitrate (NO3) loss from agricultural fields while maintaining or improving crop yields. The goal of this study was to quantify the impact of drainage water management on dra...

Relative importance of impervious area, drainage density, width function, and subsurface storm drainage on flood runoff from an urbanized catchment

NASA Astrophysics Data System (ADS)

Ogden, Fred L.; Raj Pradhan, Nawa; Downer, Charles W.; Zahner, Jon A.

2011-12-01

The literature contains contradictory conclusions regarding the relative effects of urbanization on peak flood flows due to increases in impervious area, drainage density and width function, and the addition of subsurface storm drains. We used data from an urbanized catchment, the 14.3 km2 Dead Run watershed near Baltimore, Maryland, USA, and the physics-based gridded surface/subsurface hydrologic analysis (GSSHA) model to examine the relative effect of each of these factors on flood peaks, runoff volumes, and runoff production efficiencies. GSSHA was used because the model explicitly includes the spatial variability of land-surface and hydrodynamic parameters, including subsurface storm drains. Results indicate that increases in drainage density, particularly increases in density from low values, produce significant increases in the flood peaks. For a fixed land-use and rainfall input, the flood magnitude approaches an upper limit regardless of the increase in the channel drainage density. Changes in imperviousness can have a significant effect on flood peaks for both moderately extreme and extreme storms. For an extreme rainfall event with a recurrence interval in excess of 100 years, imperviousness is relatively unimportant in terms of runoff efficiency and volume, but can affect the peak flow depending on rainfall rate. Changes to the width function affect flood peaks much more than runoff efficiency, primarily in the case of lower density drainage networks with less impermeable area. Storm drains increase flood peaks, but are overwhelmed during extreme rainfall events when they have a negligible effect. Runoff in urbanized watersheds with considerable impervious area shows a marked sensitivity to rainfall rate. This sensitivity explains some of the contradictory findings in the literature.

Isotopic mixing model for quantifying contributions of soil water and groundwater in subsurface ('tile') drainage

NASA Astrophysics Data System (ADS)

Kennedy, C. D.; Gall, H.; Jafvert, C. T.; Bowen, G. J.

2010-12-01

Subsurface (‘tile’) drainage, consisting of buried grids of perforated pipe, has provided a means of converting millions of acres of poorly drained soils in the Midwestern U.S. into fertile cropland. However, by altering pathways and rates of soil water and groundwater movement through agricultural lands, this practice may accelerate the loss of nitrate and other agrochemicals. To better understand the hydrological controls on nitrogen dynamics in artificially drained agricultural watersheds, a field sampling program has been established at the Animal Science Research and Education Center (ASREC) at Purdue University (West Lafayette, Indiana) to (1) measure precipitation amount, tile flow, and water-table elevation, and (2) collect water samples for analysis of nitrate, major ions, and oxygen isotope ratios in precipitation, tile drainage, shallow (1 m) and deep (3 m) groundwater, and soil water during storm events. Preliminary physical, chemical, and isotopic data collected at the ASREC show a coincident timing of peak storm ‘event water’ and peak nitrate flux in tile drainage, suggesting significant routing of infiltrating event water. In this work, we aim to refine our understanding of tile drainage at the ASREC by developing a mixing model for partitioning contributions of soil water and groundwater in tile drainage during several storm runoff events ranging in precipitation intensity and coinciding with varying antecedent soil moisture conditions. The results of our model will describe tile drainage in terms of its hydrological components, soil water and groundwater, which in turn will provide a means of incorporating the effects of tile drainage in surface/subsurface hydrological transport models.

Nutrient transport through a Vegetative Filter Strip with subsurface drainage.

PubMed

Bhattarai, Rabin; Kalita, Prasanta Kumar; Patel, Mita Kanu

2009-04-01

The transport of nutrients and soil sediments in runoff has been recognized as a noteworthy environmental issue. Vegetative Filter Strips (VFS) have been used as one of the best management practices (BMPs) for retaining nutrients and sediments from surface runoff, thus preventing the pollutants from reaching receiving waters. However, the effectiveness of a VFS when combined with a subsurface drainage system has not been investigated previously. This study was undertaken to monitor the retention and transport of nutrients within a VFS that had a subsurface drainage system installed at a depth of 1.2 m below the soil surface. Nutrient concentrations of NO(3)-N (Nitrate Nitrogen), PO(-)(4) (Orthophosphorus), and TP (Total Phosphorus) were measured in surface water samples (entering and leaving the VFS), and subsurface outflow. Soil samples were collected and analyzed for plant available Phosphorus (Bray P1) and NO(3)-N concentrations. Results showed that PO(-)(4), NO(3)-N, and TP concentrations decreased in surface flow through the VFS. Many surface outflow water samples from the VFS showed concentration reductions of as much as 75% for PO(-)(4) and 70% for TP. For subsurface outflow water samples through the drainage system, concentrations of PO(-)(4) and TP decreased but NO(3)-N concentrations increased in comparison to concentrations in surface inflow samples. Soil samples that were collected from various depths in the VFS showed a minimal buildup of nutrients in the top soil profile but indicated a gradual buildup of nutrients at the depth of the subsurface drain. Results demonstrate that although a VFS can be very effective in reducing runoff and nutrients from surface flow, the presence of a subsurface drain underneath the VFS may not be environmentally beneficial. Such a combination may increase NO(3)-N transport from the VFS, thus invalidating the purpose of the BMP.

Long-Term Hydrologic Impacts of Controlled Drainage Using DRAINMOD

NASA Astrophysics Data System (ADS)

Saadat, S.; Bowling, L. C.; Frankenberger, J.

2017-12-01

Controlled drainage is a management strategy designed to mitigate water quality issues caused by subsurface drainage but it may increase surface ponding and runoff. To improve controlled drainage system management, a long-term and broader study is needed that goes beyond the experimental studies. Therefore, the goal of this study was to parametrize the DRAINMOD field-scale, hydrologic model for the Davis Purdue Agricultural Center located in Eastern Indiana and to predict the subsurface drain flow and surface runoff and ponding at this research site. The Green-Ampt equation was used to characterize the infiltration, and digital elevation models (DEMs) were used to estimate the maximum depressional storage as the surface ponding parameter inputs to DRAINMOD. Hydraulic conductivity was estimated using the Hooghoudt equation and the measured drain flow and water table depths. Other model inputs were either estimated or taken from the measurements. The DRAINMOD model was calibrated and validated by comparing model predictions of subsurface drainage and water table depths with field observations from 2012 to 2016. Simulations based on the DRAINMOD model can increase understanding of the environmental and hydrological effects over a broader temporal and spatial scale than is possible using field-scale data and this is useful for developing management recommendations for water resources at field and watershed scales.

A case study examining the efficacy of drainage setbacks for limiting effects to wetlands in the Prairie Pothole Region, USA

USGS Publications Warehouse

Tangen, Brian; Finocchiaro, Raymond

2017-01-01

The enhancement of agricultural lands through the use of artificial drainage systems is a common practice throughout the United States, and recently the use of this practice has expanded in the Prairie Pothole Region. Many wetlands are afforded protection from the direct effects of drainage through regulation or legal agreements, and drainage setback distances typically are used to provide a buffer between wetlands and drainage systems. A field study was initiated to assess the potential for subsurface drainage to affect wetland surface-water characteristics through a reduction in precipitation runoff, and to examine the efficacy of current U.S. Department of Agriculture drainage setback distances for limiting these effects. Surface-water levels, along with primary components of the catchment water balance, were monitored over 3 y at four seasonal wetland catchments situated in a high-relief terrain (7–11% slopes). During the second year of the study, subsurface drainage systems were installed in two of the catchments using drainage setbacks, and the drainage discharge volumes were monitored. A catchment water-balance model was used to assess the potential effect of subsurface drainage on wetland hydrology and to assess the efficacy of drainage setbacks for mitigating these effects. Results suggest that overland precipitation runoff can be an important component of the seasonal water balance of Prairie Pothole Region wetlands, accounting on average for 34% (19–49%) or 45% (39–49%) of the annual (includes snowmelt runoff) or seasonal (does not include snowmelt) input volumes, respectively. Seasonal (2014–2015) discharge volumes from the localized drainage systems averaged 81 m3 (31–199 m3), and were small when compared with average combined inputs of 3,745 m3 (1,214–6,993 m3) from snowmelt runoff, direct precipitation, and precipitation runoff. Model simulations of reduced precipitation runoff volumes as a result of subsurface drainage systems showed that ponded wetland surface areas were reduced by an average of 590 m2 (141–1,787 m2), or 24% (3–46%), when no setbacks were used (drainage systems located directly adjacent to wetland). Likewise, wetland surface areas were reduced by an average of 141 m2 (23–464 m2), or 7% (1–28%), when drainage setbacks (buffer) were used. In totality, the field data and model simulations suggest that the drainage setbacks should reduce, but not eliminate, impacts to the water balance of the four wetlands monitored in this study that were located in a high-relief terrain. However, further study is required to assess the validity of these conclusions outside of the limited parameters (e.g., terrain, weather, soils) of this study and to examine potential ecological effects of altered wetland hydrology.

Subsurface drainage processes and management impacts

Treesearch

Elizabeth T. Keppeler; David Brown

1998-01-01

Storm-induced streamflow in forested upland watersheds is linked to rainfall by transient, variably saturated flow through several different flow paths. In the absence of exposed bedrock, shallow flow-restrictive layers, or compacted soil surfaces, virtually all of the infiltrated rainfall reaches the stream as subsurface flow. Subsurface runoff can occur within...

Effective and efficient agricultural drainage pipe mapping with UAS thermal infrared imagery: a case study

USDA-ARS?s Scientific Manuscript database

Effective and efficient methods are needed to map agricultural subsurface drainage systems. Visible (VIS), near infrared (NIR), and/or thermal infrared (TIR) imagery obtained by unmanned aircraft systems (UAS) may provide a means for determining drainage pipe locations. Preliminary UAS surveys wit...

Quantifying subsurface hydrology effects on chemical transport in drainage ditches using a 20-meter flume

USDA-ARS?s Scientific Manuscript database

Agriculture drainage ditches serve as the veins of the Midwestern agricultural landscapes. The transport of chemical fertilizers and pesticides in these ditches affect the local and downstream ecosystems. Although much research has already been conducted on chemical transport in streams and drainage...

17beta-Estradiol and testosterone in drainage and runoff from poultry litter applications to tilled and no-till crop land under irrigation.

PubMed

Jenkins, Michael B; Endale, Dinku M; Schomberg, Harry H; Hartel, Peter G; Cabrera, Miguel L

2009-06-01

Thirteen million [corrected] metric tons of poultry litter are produced annually by poultry producers in the U.S. Poultry litter contains the sex hormones estradiol and testosterone, endocrine disruptors that have been detected in surface waters. The objective of this study was to evaluate the potential impact of poultry litter applications on estradiol and testosterone concentrations in subsurface drainage and surface runoff in irrigated crop land under no-till and conventional-till management. We conducted an irrigation study in fall of 2001 and spring of 2002. Four treatments, no-till plus poultry litter, conventional-till plus poultry litter, no-till plus conventional fertilizer, and conventional-till plus conventional fertilizer, were evaluated. Flow-weighted concentration and load ha(-1) of the two hormones were measured in drainage and runoff. Soil concentrations of estradiol and testosterone were measured. Based on comparisons to the conventional fertilizer (and control) treatments, poultry litter did not add to the flow-weighted concentration or load ha(-1) of either estradiol or testosterone in subsurface drainage or surface runoff. Significant differences were, however, observed between tillage treatments: flow-weighted concentrations of estradiol were greater for no-till than conventional-till plots of the June irrigation; and runoff loads of both estradiol and testosterone were less from no-till than conventional-till plots for the November irrigation. Although the differences between no-till and conventional-tillage appeared to affect the hydrologic transport of both hormones, the differences appeared to have inconsequential environmental impact.

Design and hydrologic performance of a tile drainage treatment wetland in Minnesota, USA

USDA-ARS?s Scientific Manuscript database

Treatment wetlands are increasingly needed to remove nitrate from agricultural drainage water to protect downstream waters such as the Gulf of Mexico. A 0.10 ha wetland was designed,installed and monitored to treat subsurface drainage flow from farmland in Minnesota, USA. This project sought to deve...

Imaging Preferential Flow Pathways of Contaminants from Passive Acid Mine Drainage Mitigation Sites Using Electrical Resistivity

NASA Astrophysics Data System (ADS)

Kelley, N.; Mount, G.; Terry, N.; Herndon, E.; Singer, D. M.

2017-12-01

The Critical Zone represents the surficial and shallow layer of rock, air, water, and soil where most interactions between living organisms and the Earth occur. Acid mine drainage (AMD) resulting from coal extraction can influence both biological and geochemical processes across this zone. Conservative estimates suggest that more than 300 million gallons of AMD are released daily, making this acidic solution of water and contaminants a common issue in areas with legacy or current coal extraction. Electrical resistivity imaging (ERI) provides a rapid and minimally invasive method to identify and monitor contaminant pathways from AMD remediation systems in the subsurface of the Critical Zone. The technique yields spatially continuous data of subsurface resistivity that can be inverted to determine electrical conductivity as a function of depth. Since elevated concentrations of heavy metals can directly influence soil conductivity, ERI data can be used to trace the flow pathways or perhaps unknown mine conduits and transport of heavy metals through the subsurface near acid mine drainage sources. This study aims to examine preferential contaminant migration from those sources through substrate pores, fractures, and shallow mine workings in the near subsurface surrounding AMD sites in eastern Ohio and western Pennsylvania. We utilize time lapse ERI measures during different hydrologic conditions to better understand the variability of preferential flow pathways in relation to changes in stage and discharge within the remediation systems. To confirm ERI findings, and provide constraint to geochemical reactions occurring in the shallow subsurface, we conducted Inductively Coupled Plasma (ICP) spectrometry analysis of groundwater samples from boreholes along the survey transects. Through these combined methods, we can provide insight into the ability of engineered systems to contain and isolate metals in passive acid mine drainage treatment systems.

Opportunities for Reducing Nitrate Export from Drainage Systems through In-field Nitrogen Management, Cropping Practices, and Drainage Design and Management

NASA Astrophysics Data System (ADS)

Helmers, M.; Zhou, X.; Qi, Z.; Christianson, R.; Pederson, C.

2011-12-01

Subsurface drainage systems are widely used throughout the upper Midwest corn-belt. While the use of these drainage systems has greatly increased crop production, they have also increased nitrate-nitrogen export to downstream waterbodies. As a result, there is a need to evaluate and implement management practices that have potential to reduce nitrate-nitrogen loss. A twenty year study in Iowa has shown that major factors in nitrate-nitrogen loss are land use and hydrology. Studies from north-central Iowa have also indicated that nitrogen application rate and to a lesser degree timing of nitrogen application important factors for nitrate-nitrogen loss. A four-year (2007-2010) drainage management study in southeast Iowa indicates that shallow and controlled drainage systems have potential to decrease subsurface drainage and thereby reduce nitrate-N loss from drain water but the level of implementation of controlled drainage may be limited by topography. Cropping practices through cover crops or perennial biomass crops have also been documented to have potential to reduce downstream nitrate-nitrogen export but the level of implementation may be limited by management and economic considerations. To achieve reduction goals for protection of local and regional water quality will require a combination of these practices at the landscape scale.

Location and assessment of drainage pipes beneath farm fields and golf course greens using ground penetrating radar: A research summary

USDA-ARS?s Scientific Manuscript database

Enhancing the efficiency of soil water removal, and in turn crop productivity, on farmland already containing a subsurface drainage system, typically involves installing new drain lines between the old ones. However, before this approach can be attempted, the older drainage pipes need to be located...

Effect of drainage in unbound aggregate bases on flexible pavement performance.

DOT National Transportation Integrated Search

2008-05-01

It has been well demonstrated that a positive subsurface drainage is beneficial in enhancing pavement performance and thus extending pavement service life. Typical permeable base materials include asphalt/cement-treated, open-graded aggregates and un...

Evaluation on the Efficiency of Subsurface Drainage in Chiu-Fen Landslide at Northern Taiwan

NASA Astrophysics Data System (ADS)

Ying, L. Y.; Lin, D. G.

2015-12-01

For administrative district, the Chiu-Fen landslide is situated at northern Taiwan and comes within the jurisdiction of Ruei-Fang district, New Taipei City Government. Chiu-Fen village is a famous spot for sightseeing and tourism in Southeast Asia. In the last decade, for economic purpose, a vast area of slope land in Chiu-Fen area was reclaimed into business and commercial districts. However, due to the complicated geological and hydrological conditions, improper reclamation, and lack of appropriate soil and water conservation facilities, large scale landslides are frequently triggered by typhoon rainfall and causes damages to the transportation and residential building in the community. As a consequence, the government initiated a comprehensive field investigations and remediation plans to stabilize the landslide from 1997 and the remediation works were concentrated on subsurface drainages, namely the application of drainage well (a vertical shaft with multi-level horizontal drainage boreholes). To investigate the efficiency of drainage wells on the landslide, the A1-profile in the landslide which covers the drainage wells W2 and W4 was selected for a series of rainfall seepage and slope stability analyses. In addition, a 48-hrs design rainfall with return period of 25, 50 and 100 years based on the local meteorological data bank was adopted for the analyses. The numerical results indicate the factor safety FS of the three potential sliding surfaces within A1-profile are constantly keeping greater than one (FS > 1.0) and without decreasing with the elapsed time during rainfall. This implies that the subsurface drainage works can drain off the infiltrated rainwater from a high intensity and long duration rainfall and preserve the slope stability of landslides from deterioration. Finally, the efficiency of the drainage wells can be evaluated quantitatively in terms of the time-dependent factor of safety and the pore water pressure distribution on several potential sliding surfaces.

Characterizing phosphorus dynamics in tile-drained agricultural fieldsof eastern Wisconsin

USGS Publications Warehouse

Madison, Allison; Ruark, Matthew; Stuntebeck, Todd D.; Komiskey, Matthew J.; Good, Laura W.; Drummy, Nancy; Cooley, Eric

2014-01-01

Artificial subsurface drainage provides an avenue for the rapid transfer of phosphorus (P) from agricultural fields to surface waters. This is of particular interest in eastern Wisconsin, where there is a concentrated population of dairy farms and high clay content soils prone to macropore development. Through collaboration with private landowners, surface and tile drainage was measured and analyzed for dissolved reactive P (DRP) and total P (TP) losses at four field sites in eastern Wisconsin between 2005 and 2009. These sites, which received frequent manure applications, represent a range of crop management practices which include: two chisel plowed corn fields (CP1, CP2), a no-till corn–soybean field (NT), and a grazed pasture (GP). Subsurface drainage was the dominant pathway of water loss at each site accounting for 66–96% of total water discharge. Average annual flow-weighted (FW) TP concentrations were 0.88, 0.57, 0.21, and 1.32 mg L−1 for sites CP1, CP2, NT, and GP, respectively. Low TP concentrations at the NT site were due to tile drain interception of groundwater flow where large volumes of tile drainage water diluted the FW-TP concentrations. Subsurface pathways contributed between 17% and 41% of the TP loss across sites. On a drainage event basis, total drainage explained between 36% and 72% of the event DRP loads across CP1, CP2, and GP; there was no relationship between event drainflow and event DRP load at the NT site. Manure applications did not consistently increase P concentrations in drainflow, but annual FW-P concentrations were greater in years receiving manure applications compared to years without manure application. Based on these field measures, P losses from tile drainage must be integrated into field level P budgets and P loss calculations on heavily manured soils, while also acknowledging the unique drainage patterns observed in eastern Wisconsin.

Characterizing phosphorus dynamics in tile-drained agricultural fields of eastern Wisconsin

NASA Astrophysics Data System (ADS)

Madison, Allison M.; Ruark, Matthew D.; Stuntebeck, Todd D.; Komiskey, Matthew J.; Good, Lara W.; Drummy, Nancy; Cooley, Eric T.

2014-11-01

Artificial subsurface drainage provides an avenue for the rapid transfer of phosphorus (P) from agricultural fields to surface waters. This is of particular interest in eastern Wisconsin, where there is a concentrated population of dairy farms and high clay content soils prone to macropore development. Through collaboration with private landowners, surface and tile drainage was measured and analyzed for dissolved reactive P (DRP) and total P (TP) losses at four field sites in eastern Wisconsin between 2005 and 2009. These sites, which received frequent manure applications, represent a range of crop management practices which include: two chisel plowed corn fields (CP1, CP2), a no-till corn-soybean field (NT), and a grazed pasture (GP). Subsurface drainage was the dominant pathway of water loss at each site accounting for 66-96% of total water discharge. Average annual flow-weighted (FW) TP concentrations were 0.88, 0.57, 0.21, and 1.32 mg L-1 for sites CP1, CP2, NT, and GP, respectively. Low TP concentrations at the NT site were due to tile drain interception of groundwater flow where large volumes of tile drainage water diluted the FW-TP concentrations. Subsurface pathways contributed between 17% and 41% of the TP loss across sites. On a drainage event basis, total drainage explained between 36% and 72% of the event DRP loads across CP1, CP2, and GP; there was no relationship between event drainflow and event DRP load at the NT site. Manure applications did not consistently increase P concentrations in drainflow, but annual FW-P concentrations were greater in years receiving manure applications compared to years without manure application. Based on these field measures, P losses from tile drainage must be integrated into field level P budgets and P loss calculations on heavily manured soils, while also acknowledging the unique drainage patterns observed in eastern Wisconsin.

Effect of subsurface drainage on runoff and sediment yield from an agricultural watershed in western Oregon, U.S.A.

NASA Astrophysics Data System (ADS)

Istok, J. D.; Kling, G. F.

1983-09-01

Rainfall, watershed runoff and suspended-sediment concentrations for three small watersheds (0.46, 1.4 and 6.0 ha in size) were measured continuously for four winter rainfall seasons. The watersheds were fall-planted to winter wheat and were located on the hilly western margins of the Willamette Valley, Oregon. Following two rainfall seasons of data collection, a subsurface drainage system (consisting of a patterned arrangement of 10-cm plastic tubing at a depth of 1.0 m and a spacing of 12 m) was installed on the 1.4-ha watershed (watershed 2). Perched water tables were lowered and seepage was reduced on watershed 2 following the installation of the drainage system. The reductions were quantified with a water-table index (cumulative integrated excess). Watershed runoff and sediment yield from watershed 2 were decreased by ˜65 and ˜55%, respectively. These reductions were estimated from double mass curves and by statistical regression on a set of hydrograph variables. Maximum flow and average flow rates were decreased and the time from the beginning of a storm to the peak flow (lag time) increased. It is concluded that subsurface drainage can be an effective management practice for erosion control in western Oregon.

Experimental utilization of tire shreds to enhance highway drainage.

DOT National Transportation Integrated Search

2001-03-01

This project investigates the practical benefits of using shredded tires as a free draining material : in a subsurface French drain to enhance drainage along a section of highway. French drains are : below-grade structures designed to re-direct groun...

Open inlet conversion: Water quality benefits of two designs

USDA-ARS?s Scientific Manuscript database

Open surface inlets that connect to subsurface tile drainage systems provide a direct pathway for movement of sediment, nutrients, and agrochemicals to surface waters. This study was conducted to determine the reduction in drainage effluent total suspended sediment (TSS) and phosphorus (P) concentr...

Determination of the Thermal Properties of Sands as Affected by Water Content, Drainage/Wetting, and Porosity Conditions for Sands With Different Grain Sizes

NASA Astrophysics Data System (ADS)

Smits, K. M.; Sakaki, T.; Limsuwat, A.; Illangasekare, T. H.

2009-05-01

It is widely recognized that liquid water, water vapor and temperature movement in the subsurface near the land/atmosphere interface are strongly coupled, influencing many agricultural, biological and engineering applications such as irrigation practices, the assessment of contaminant transport and the detection of buried landmines. In these systems, a clear understanding of how variations in water content, soil drainage/wetting history, porosity conditions and grain size affect the soil's thermal behavior is needed, however, the consideration of all factors is rare as very few experimental data showing the effects of these variations are available. In this study, the effect of soil moisture, drainage/wetting history, and porosity on the thermal conductivity of sandy soils with different grain sizes was investigated. For this experimental investigation, several recent sensor based technologies were compiled into a Tempe cell modified to have a network of sampling ports, continuously monitoring water saturation, capillary pressure, temperature, and soil thermal properties. The water table was established at mid elevation of the cell and then lowered slowly. The initially saturated soil sample was subjected to slow drainage, wetting, and secondary drainage cycles. After liquid water drainage ceased, evaporation was induced at the surface to remove soil moisture from the sample to obtain thermal conductivity data below the residual saturation. For the test soils studied, thermal conductivity increased with increasing moisture content, soil density and grain size while thermal conductivity values were similar for soil drying/wetting behavior. Thermal properties measured in this study were then compared with independent estimates made using empirical models from literature. These soils will be used in a proposed set of experiments in intermediate scale test tanks to obtain data to validate methods and modeling tools used for landmine detection.

Investigation of ground-water contamination at a drainage ditch, Installation Restoration Site 4, Naval Air Station Corpus Christi, Corpus Christi, Texas, 2005–06

USGS Publications Warehouse

Vroblesky, Don A.; Casey, Clifton C.

2007-01-01

The U.S. Geological Survey, in cooperation with the Naval Facilities Engineering Command Southeast, used newly developed sampling methods to investigate ground-water contamination by chlorobenzenes beneath a drainage ditch on the southwestern side of Installation Restoration Site 4, Naval Air Station Corpus Christi, Corpus Christi, Texas, during 2005-06. The drainage ditch, which is a potential receptor for ground-water contaminants from Installation Restoration Site 4, intermittently discharges water to Corpus Christi Bay. This report uses data from a new type of pore-water sampler developed for this investigation and other methods to examine the subsurface contamination beneath the drainage ditch. Analysis of ground water from the samplers indicated that chlorobenzenes (maximum detected concentration of 160 micrograms per liter) are present in the ground water beneath the ditch. The concentrations of dissolved oxygen in the samples (less than 0.05-0.4 milligram per liter) showed that the ground water beneath and near the ditch is anaerobic, indicating that substantial chlorobenzene biodegradation in the aquifer beneath the ditch is unlikely. Probable alternative mechanisms of chlorobenzene removal in the ground water beneath the drainage ditch include sorption onto the organic-rich sediment and contaminant depletion by cattails through uptake, sorption, and localized soil aeration.

Profiling USGA putting greens using GPR - an as-built surveying method

USDA-ARS?s Scientific Manuscript database

Golf course greens that are constructed to U.S. Golf Association (USGA) standards must adhere to strict installation specifications in order to maintain proper subsurface drainage. Because the infrastructure is buried, it can be difficult to ascertain if these drainage pipes were properly installed...

AMELIORATION OF ACID MINE DRAINAGE USING REACTIVE MIXTURES IN PERMEABLE REACTIVE BARRIERS

EPA Science Inventory

The generation and release of acidic drainage from mine wastes is an environmental problem of international scale. The use of zero-valent iron and/or iron mixtures in subsurface Permeable Reactive Barriers (PRB) presents a possible passive alternative for remediating acidic grou...

Corn yield under subirrigation and future climate scenarios in the Maumee river basin

USDA-ARS?s Scientific Manuscript database

Subirrigation has been proposed as a water table management practice to maintain appropriate soil water content during periods of high crop water demand on subsurface drained croplands in the Corn Belt. Subirrigation takes advantage of the subsurface drainage systems already installed on drained agr...

Transport of tylosin and tylosin-resistance genes in subsurface drainage water from manured fields

USDA-ARS?s Scientific Manuscript database

Animal agriculture appears to contribute to the spread of antibiotic resistance genes, but few studies have quantified gene transport in agricultural fields. The transport of tylosin, tylosin-resistance genes (erm B, F, A) and tylosin-resistant Enterococcus were measured in tile drainage water from ...

Modeling nutrient removal using watershed-scale implementation of the two-stage ditch

USDA-ARS?s Scientific Manuscript database

Western Lake Erie Basin (WLEB) is the most intensively farmed region of the Great Lakes. Because of the flat topography and poorly-drained soils many farmers rely on drainage management practices (e.g., subsurface tile drainage, ditch channelization) to maintain productive agriculture. However, th...

Dissipation of atrazine, enrofloxacin, and sulfamethazine in wood chip bioreactors and impact on denitrification

USDA-ARS?s Scientific Manuscript database

Wood chip bioreactors are receiving increasing attention as a means of reducing nitrate in subsurface tile drainage systems. Agrochemicals in tile drainage water entering wood chip bioreactors can be retained or degraded and may impact denitrification. The degradation of 5 mg L-1 atrazine, enrofloxa...

Stormwater Management Decision Support System for Using Low Impact Development Best Management Practices in Industrial Areas

DTIC Science & Technology

2015-05-30

particulates can be trapped in the inlet then washed into the drainage system in a large storm event...and P. Matin. 2005. Performance and Whole-Life Costs of Best Management Practices and Sustainable Urban Drainage Systems . Report #01CTS21TA. Water...subsurface drainage system consisting of a parallel perforated PVC pipe system in a stone bed that connects to the third chamber, which is the discharge

Effectiveness of oat and rye cover crops in reducing nitrate losses in drainage water

USDA-ARS?s Scientific Manuscript database

A significant portion of the NO3 from agricultural fields that contaminates surface waters in the Midwest Corn Belt is transported to streams or rivers by subsurface drainage systems or “tiles”. Previous research has shown that N fertilizer management alone is not sufficient for reducing NO3 concent...

Effects of subsurface drainage systems on water and nitrogen footprints simulated with RZWQM2

USDA-ARS?s Scientific Manuscript database

When considering the use of drainage water management (DWM) in the Midwest to reduce nutrient contributions to the Northern Gulf of Mexico Hypoxic Zone, it is essential to understand the long-term performance of these systems. Few studies have evaluated long-term impacts of DWM and the simulation of...

Use of industrial byproducts to filter PO43- and pesticides in golf green drainage water

USDA-ARS?s Scientific Manuscript database

Golf courses are vulnerable to phosphate (PO43-) and pesticide loss by infiltration because of the sandy, porous grass rooting media used and presence of subsurface tile drainage. In this study, a blend of industrial byproducts, including granulated blast furnace slag (GBFS), cement kiln dust (CKD),...

Use of industrial byproducts to filter nutrients and pesticides in a golf green’s drainage water

USDA-ARS?s Scientific Manuscript database

Golf courses are particularly vulnerable to phosphate (PO43-) and pesticide loss by infiltration because of the sandy, porous grass rooting media used and presence of subsurface tile drainage. In this study, an effort was made to filter PO43-, chlorothalonil, mefenoxam, and propiconazole in putting ...

Performance of dentrification beds for removing nitrate from drainage water at cold temperatures

USDA-ARS?s Scientific Manuscript database

Transport of soluble nitrogen and phosphorus to water bodies has been a concern for many years due to human health issues, and is a major contributor to the formation of oxygen deficiency in aquatic ecosystems. Agricultural subsurface drainage is one pathway for transport of excess nutrients to surf...

Effect of alternative surface inlet designs on sediment and phosphorus drainage losses

USDA-ARS?s Scientific Manuscript database

Open surface inlets that connect to subsurface tile drainage systems provide a direct pathway for sediment, nutrients, and agrochemicals to surface waters. This study was conducted to determine whether modifying open inlets by burying them in gravel capped with 30 cm of sandy clay loam soil or in ve...

Comprehensive nitrogen budgets for controlled tile drainage fields in eastern ontario, Canada.

PubMed

Sunohara, M D; Craiovan, E; Topp, E; Gottschall, N; Drury, C F; Lapen, D R

2014-03-01

Excessive N loading from subsurface tile drainage has been linked to water quality degradation. Controlled tile drainage (CTD) has the potential to reduce N losses via tile drainage and boost crop yields. While CTD can reduce N loss from tile drainage, it may increase losses through other pathways. A multiple-year field-scale accounting of major N inputs and outputs during the cropping season was conducted on freely drained and controlled tile drained agricultural fields under corn ( L.)-soybean [ (L.) Merr.] production systems in eastern Ontario, Canada. Greater predicted gaseous N emissions for corn and soybean and greater observed lateral seepage N losses were observed for corn and soybean fields under CTD relative to free-draining fields. However, observed N losses from tile were significantly lower for CTD fields, in relation to freely drained fields. Changes in residual soil N were essentially equivalent between drainage treatments, while mass balance residual terms were systematically negative (slightly more so for CTD). Increases in plant N uptake associated with CTD were observed, probably resulting in higher grain yields for corn and soybean. This study illustrates the benefits of CTD in decreasing subsurface tile drainage N losses and boosting crop yields, while demonstrating the potential for CTD to increase N losses via other pathways related to gaseous emissions and groundwater seepage. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Winery wastewater treatment using the land filter technique.

PubMed

Christen, E W; Quayle, W C; Marcoux, M A; Arienzo, M; Jayawardane, N S

2010-08-01

This study outlines a new approach to the treatment of winery wastewater by application to a land FILTER (Filtration and Irrigated cropping for Land Treatment and Effluent Reuse) system. The land FILTER system was tested at a medium size rural winery crushing approximately 20,000 tonnes of grapes. The approach consisted of a preliminary treatment through a coarse screening and settling in treatment ponds, followed by application to the land FILTER planted to pasture. The land FILTER system efficiently dealt with variable volumes and nutrient loads in the wastewater. It was operated to minimize pollutant loads in the treated water (subsurface drainage) and provide adequate leaching to manage salt in the soil profile. The land FILTER system was effective in neutralizing the pH of the wastewater and removing nutrient pollutants to meet EPA discharge limits. However, suspended solids (SS) and biological oxygen demand (BOD) levels in the subsurface drainage waters slightly exceeded EPA limits for discharge. The high organic content in the wastewater initially caused some soil blockage and impeded drainage in the land FILTER site. This was addressed by reducing the hydraulic loading rate to allow increased soil drying between wastewater irrigations. The analysis of soil characteristics after the application of wastewater found that there was some potassium accumulation in the profile but sodium and nutrients decreased after wastewater application. Thus, the wastewater application and provision of subsurface drainage ensured adequate leaching, and so was adequate to avoid the risk of soil salinisation. Crown Copyright 2010. Published by Elsevier Ltd. All rights reserved.

Reducing phosphorus loss in tile water with managed drainage in a claypan soil.

PubMed

Nash, Patrick R; Nelson, Kelly A; Motavalli, Peter P; Nathan, Manjula; Dudenhoeffer, Chris

2015-03-01

Installing subsurface tile drain systems in poorly drained claypan soils to improve corn ( L.) yields could potentially increase environmental phosphorus (P) loss through the tile drainage system. The objectives of the study were to quantify the average concentration and loss of ortho-P in tile drain water from a claypan soil and to determine whether managed subsurface drainage (MD) could reduce ortho-P loss in tile water compared with free subsurface drainage (FD). Flow-weighted ortho-P concentration in the tile water was significantly lower with MD (0.09 mg L) compared with that of FD (0.15 mg L). Ortho-P loss in the tile water of this study was reduced with MD (36 g ha) by 80% compared with FD (180 g ha). Contrary to previous research, reduced ortho-P loss observed over the 4-yr study was not solely due to the reduced amount of water drained annually (63%) with MD compared with FD. During the spring period, when flow was similar between MD and FD, the concentration of ortho-P in the tile water generally was lower with MD compared with FD, which resulted in significantly less ortho-P loss with MD. We speculate that MD's ability to conserve water during the dry summer months increased corn's uptake of water and P, which reduced the amount of P available for leaching loss in the subsequent springs. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Durability of Drainage Improvement by Combination of Main Drain and Trench Drains with Vertical Drains in Clayey Field Converted from Paddy to Upland Use

NASA Astrophysics Data System (ADS)

Adachi, Kazuhide; Ohno, Satoshi; Furuhata, Masami; Ogura, Chikara; Tanimoto, Takeshi

The drainage efficiency of a subsurface drainage system for avoidance of standing water on the plow pan of clayey field was evaluated. A subsurface drainage system with a main drain and orthogonally adjoined rice husk trench drains joined by vertical rice husk drains was constructed on a test plot and compared to an identical control plot of paddy field converted to upland use under soybean cultivation. The ratio of total underdrain discharge to rainfall in the improved plot greatly increased over two years compared to that in a control plot. In the improved plot, the peak underdrain discharge per hour associated with some heavy rainfalls was around 3 mm/h in the first year but decreased to about 2 mm/h in the second year. By improving drainage in the paddy field, standing water on the plow pan was quickly eliminated after rain events and the period of flooding on the plow pan during the soybean growing season was greatly reduced. However, underdrain discharge in the improved plot decreased greatly in the third year to be at the same level as in the control plot, and rain water flooded the plow pan for extended periods of time.

Projected climate change effects on subsurface drainage and the performance of controlled drainage in the Western Lake Erie Basin

USDA-ARS?s Scientific Manuscript database

The US Midwest is expected to experience higher intensity rainfall events along with an increased chance of drought during the mid- and late-21st century under climate change. Development of strategies to mitigate the impact of these projected changes on agricultural production may be critical for e...

Illinois drainage water management demonstration project

USGS Publications Warehouse

Pitts, D.J.; Cooke, R.; Terrio, P.J.; ,

2004-01-01

Due to naturally high water tables and flat topography, there are approximately 4 million ha (10 million ac) of farmland artificially drained with subsurface (tile) systems in Illinois. Subsurface drainage is practiced to insure trafficable field conditions for farm equipment and to reduce crop stress from excess water within the root zone. Although drainage is essential for economic crop production, there have been some significant environmental costs. Tile drainage systems tend to intercept nutrient (nitrate) rich soil-water and shunt it to surface water. Data from numerous monitoring studies have shown that a significant amount of the total nitrate load in Illinois is being delivered to surface water from tile drainage systems. In Illinois, these drainage systems are typically installed without control mechanisms and allow the soil to drain whenever the water table is above the elevation of the tile outlet. An assessment of water quality in the tile drained areas of Illinois showed that approximately 50 percent of the nitrate load was being delivered through the tile systems during the fallow period when there was no production need for drainage to occur. In 1998, a demonstration project to introduce drainage water management to producers in Illinois was initiated by NRCS4 An initial aspect of the project was to identify producers that were willing to manage their drainage system to create a raised water table during the fallow (November-March) period. Financial assistance from two federal programs was used to assist producers in retrofitting the existing drainage systems with control structures. Growers were also provided guidance on the management of the structures for both water quality and production benefits. Some of the retrofitted systems were monitored to determine the effect of the practice on water quality. This paper provides background on the water quality impacts of tile drainage in Illinois, the status of the demonstration project, preliminary monitoring results, and other observations.

Evaluating the spatial distribution of water balance in a small watershed, Pennsylvania

NASA Astrophysics Data System (ADS)

Yu, Zhongbo; Gburek, W. J.; Schwartz, F. W.

2000-04-01

A conceptual water-balance model was modified from a point application to be distributed for evaluating the spatial distribution of watershed water balance based on daily precipitation, temperature and other hydrological parameters. The model was calibrated by comparing simulated daily variation in soil moisture with field observed data and results of another model that simulates the vertical soil moisture flow by numerically solving Richards' equation. The impacts of soil and land use on the hydrological components of the water balance, such as evapotranspiration, soil moisture deficit, runoff and subsurface drainage, were evaluated with the calibrated model in this study. Given the same meteorological conditions and land use, the soil moisture deficit, evapotranspiration and surface runoff increase, and subsurface drainage decreases, as the available water capacity of soil increases. Among various land uses, alfalfa produced high soil moisture deficit and evapotranspiration and lower surface runoff and subsurface drainage, whereas soybeans produced an opposite trend. The simulated distribution of various hydrological components shows the combined effect of soil and land use. Simulated hydrological components compare well with observed data. The study demonstrated that the distributed water balance approach is efficient and has advantages over the use of single average value of hydrological variables and the application at a single point in the traditional practice.

Nitrate-nitrogen losses through subsurface drainage under various agricultural land covers.

PubMed

Qi, Zhiming; Helmers, Matthew J; Christianson, Reid D; Pederson, Carl H

2011-01-01

Nitrate-nitrogen (NO₃-N) loading to surface water bodies from subsurface drainage is an environmental concern in the midwestern United States. The objective of this study was to investigate the effect of various land covers on NO₃-N loss through subsurface drainage. Land-cover treatments included (i) conventional corn ( L.) (C) and soybean [ (L.) Merr.] (S); (ii) winter rye ( L.) cover crop before corn (rC) and before soybean (rS); (iii) kura clover ( M. Bieb.) as a living mulch for corn (kC); and (iv) perennial forage of orchardgrass ( L.) mixed with clovers (PF). In spring, total N uptake by aboveground biomass of rye in rC, rye in rS, kura clover in kC, and grasses in PF were 14.2, 31.8, 87.0, and 46.3 kg N ha, respectively. Effect of land covers on subsurface drainage was not significant. The NO₃-N loss was significantly lower for kC and PF than C and S treatments (p < 0.05); rye cover crop did not reduce NO₃-N loss, but NO₃-N concentration was significantly reduced in rC during March to June and in rS during July to November (p < 0.05). Moreover, the increase of soil NO₃-N from early to late spring in rS was significantly lower than the S treatment (p < 0.05). This study suggests that kC and PF are effective in reducing NO₃-N loss, but these systems could lead to concerns relative to grain yield loss and change in farming practices. Management strategies for kC need further study to achieve reasonable corn yield. The effectiveness of rye cover crop on NO-N loss reduction needs further investigation under conditions of different N rates, wider weather patterns, and fall tillage. by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

SUBSURFACE RESIDENCE TIMES AS AN ALGORITHM FOR AQUIFER SENSITIVITY MAPPING: TESTING THE CONCEPT WITH GROUND WATER MODELS IN THE CONTENTNEA CREEK BASIN, NORTH CAROLINA, USA

EPA Science Inventory

This poster will present a modeling and mapping assessment of landscape sensitivity to non-point source pollution as applied to a hierarchy of catchment drainages in the Coastal Plain of the state of North Carolina. Analysis of the subsurface residence time of water in shallow a...

Drainage lineaments in late Quaternary sediments, Ascension and East Baton Rouge Parishes, Louisiana

DOE Office of Scientific and Technical Information (OSTI.GOV)

Birdseye, R.U.; Christians, G.L.; Olson, J.L.

1988-09-01

Analysis of conventional aerial photographs, NHAP imagery, and topographic maps covering Ascension and East Baton Rouge Parishes in southeastern Louisiana reveals fine-textured parallel sets of drainage lineaments and numerous fluvial anomalies. Linear physiographic features include stream channels, natural levees, stream valleys, rectangular drainage patterns, and terrace scarps. Late Pleistocene and Holocene surfaces are involved, but only small drainages are affected and no such control is exerted on the Mississippi river. Most lineaments show preferred northeast and northwest trends. Orientations of mapped joint systems are similar to lineament orientations, which suggests that trends of physiographic lineaments are controlled by underlying structure.more » Several surface faults are mapped in the northern portion of the region, all of which strike essentially east-west. Salt domes are located in the subsurface to the south; however, they have no geomorphic expression and do not seem to be associated with the lineaments. Therefore, joints rather than faults or salt diapirs are a likely structural control. Joints may provide paths of weakness along which surface drainage might develop preferentially. Thus, joints probably exert an important control on the geomorphology of the region. The joint pattern appears to be related to the local distribution of the Mesozoic and Cenozoic strata, and may result from regional subsidence due to the thick accumulation of deltaic sediments. Conclusive subsurface data are currently unavailable, and shallow seismic surveys in the future may strengthen the case for an interpretation of structural control of drainage.« less

Constructed wetland attenuation of nitrogen exported in subsurface drainage from irrigated and rain-fed dairy pastures.

PubMed

Tanner, C C; Nguyen, M L; Sukias, J P S

2005-01-01

Nitrogen removal performance is reported for constructed wetlands treating subsurface drainage from irrigated and rain-fed dairy pastures in North Island, New Zealand. Flow-proportional sampling of inflow and outflow concentrations were combined with continuous flow records to calculate mass balances for the wetlands. Drainage flows from the irrigated catchment were 2.5-4 fold higher and N exports up to 5 fold higher per unit area than for the rain-fed catchment. Hydraulic and associated N loadings to the wetlands were highly pulsed, associated with rainfall, soil water status, and irrigation events. Transient pulses of organic nitrogen were an important form of N loss from the rain-fed landscape in the first year, and were very effectively removed in the wetland (> 90%). Median nitrate concentrations of approximately 10 g m(-3) in the drainage inflows were reduced by 15-67% during passage through the wetlands and annual nitrate-N loads by 16-61% (38-31 7 g N m(-2)y(-1)). Generation in the wetlands of net ammoniacal-N and organic-N (irrigated site) partially negated reduction in nitrate-N loads. The results show that constructed wetlands comprising 1-2% of catchment area can provide moderate reductions in TN export via pastoral drainage, but performance is markedly influenced by variations in seasonal loading and establishment/maturation factors.

Discovering buried channels of the Yamuna in alluvial plains of NW India using geophysical investigations: implications for major drainage reorganization during Late Quaternary

NASA Astrophysics Data System (ADS)

Paul, D.; Khan, I.; Sinha, R.

2016-12-01

Climatic changes and active tectonic movements in the northwestern plains of India during the Late Quaternary have led to the migration and abandonment of drainage systems and formation of a large number of palaeochannels. It has been postulated by previous workers that the Yamuna was flowing along the present-day dry palaeochannels of Ghaggar-Hakra riverbed >120 Ka ago and was relocated to its current position only during the Late Quaternary. However, till date, no conclusive evidence has been provided as to when and why the Yamuna avulsion occurred. This study aims to establish sub-surface existence of buried channels of paleo-Yamuna as possible courses of the paleo-Ghaggar river. Geo-electric studies using vertical electrical resistivity soundings (1D-VES), multi electrode electrical resistivity tomography (2D-ERT) and multi probe well log surveys have been carried out in one of the paleochannels of the Yamuna to map the large-scale geometry and architecture of the palaeochannel system in the subsurface. The main objective is to reconstruct the shallow subsurface stratigraphy and alluvial architecture of the interfluve between the modern Yamuna and Sutlej Rivers, in particular the linkage of the paleocourses of the Yamuna River to the drainage network of the northwestern alluvial plains. The geophysical signatures recorded as VES on two transects trending NW-SE in Karnal and Kaithal districts of Haryana at 9 and 13 locations respectively along with continuous ERT reveals the presence of subsurface fine to coarse sand bodies (20 to 30m thick) interbedded with silty clay layers that are laterally stacked. The occurrence of thick and wide subsurface sand bodies in the subsurface implies that these are the deposits of a large river system and suggests that the Yamuna was connected to the paleo-Ghaggar River as hypothesized by earlier workers based on remote sensing techniques. However, detailed sedimentological and chronological constraints are required to establish such links to unravel the stratigraphic manifestation of the buried channels, their sediment provenance and paleoclimatic conditions during the period when these river systems were active.

Subsurface irrigation of potato crop (Solanum tuberosum ssp. Andigena) in Suka Kollus with different drainage systems

NASA Astrophysics Data System (ADS)

Serrano-Coronel, Genaro; Chipana-Rivera, René; Fátima Moreno-Pérez, María; Roldán-Cañas, José

2016-04-01

Among the most important hydraulic structures of pre-Hispanic ancestral technology developed in the Andean region, we find the suka kollus, aymara word, called also waru waru, en quechua or raised fields, in English. They are raised platforms surrounded by water canals that irrigate subsurface, but also have the function of draining, to deal with floods because they are surrounding Lake Titicaca. They also have the property of generating a thermoregulatory effect to crops, depending on the configuration of the channels and platforms. Such agro-ecosystems are being abandoned, however, if properly addressed crop management and some drainage canals are replaced by underground drains for increased crop area could be very useful in enabling marginal soils affected by salts and / or excess water. For these reasons, the objective of this study was to evaluate the subsurface irrigation in the potato crop in suka kollus under a system of surface drainage, and mixed drainage (surface and subsurface). The study was conducted in marginal soils of Kallutaca area, located 30 km from the city of La Paz, Bolivia, at a height of 3892 m.a.s.l. The cultivation of the potato (Solanum tuberosum ssp. Andigena) was used. Four treatments were tested with different widths of the platforms: T1 (Control) with drainage through channels; T2 (replacing a channel by a drain); T3 (replacing two channels by two drains); T4 (replacing three channels by three drains). The flow of water into the soil from the water table was predominantly upward, except during periods of high rainfall. In terms of treatments, the flow in T1 was higher, mainly at weeks 8 to 11 after seedling emergence, coinciding with the phenological phases of flowering and at the beginning of the tuber ripening. It was followed by T3, T2 and T4 treatments, respectively. Tuber yield, if one considers that the channels detract arable land, was higher in the T3 treatment,16.4 Mg / ha, followed by T2 treatment, 15.2 Mg / ha, T1 treatment (Control) 7.3 Mg / ha and T4 treatment with 7.1 Mg / ha. Therefore, in the mixed system with two drains the best results were obtained.

Sources and fates of heavy metals in a mining-impacted stream: Temporal variability and the role of iron oxides

PubMed Central

Schaider, Laurel A.; Senn, David B.; Estes, Emily R.; Brabander, Daniel J.; Shine, James P.

2014-01-01

Heavy metal contamination of surface waters at mining sites often involves complex interactions of multiple sources and varying biogeochemical conditions. We compared surface and subsurface metal loading from mine waste pile runoff and mine drainage discharge and characterized the influence of iron oxides on metal fate along a 0.9-km stretch of Tar Creek (Oklahoma, USA), which drains an abandoned Zn/Pb mining area. The importance of each source varied by metal: mine waste pile runoff contributed 70% of Cd, while mine drainage contributed 90% of Pb, and both sources contributed similarly to Zn loading. Subsurface inputs accounted for 40% of flow and 40-70% of metal loading along this stretch. Streambed iron oxide aggregate material contained highly elevated Zn (up to 27,000 μg g−1), Pb (up to 550 μg g−1) and Cd (up to 200 μg g−1) and was characterized as a heterogeneous mixture of iron oxides, fine-grain mine waste, and organic material. Sequential extractions confirmed preferential sequestration of Pb by iron oxides, as well as substantial concentrations of Zn and Cd in iron oxide fractions, with additional accumulation of Zn, Pb, and Cd during downstream transport. Comparisons with historical data show that while metal concentrations in mine drainage have decreased by more than an order of magnitude in recent decades, the chemical composition of mine waste pile runoff has remained relatively constant, indicating less attenuation and increased relative importance of pile runoff. These results highlight the importance of monitoring temporal changes at contaminated sites associated with evolving speciation and simultaneously addressing surface and subsurface contamination from both mine waste piles and mine drainage. PMID:24867708

Subsurface geomicrobiology of the Iberian Pyritic Belt, a terrestrial analogue of Mars

NASA Astrophysics Data System (ADS)

Amils, Ricardo

Terrestrial subsurface geomicrobiology is a matter of growing interest on many levels. From a fundamental point of view, it seeks to determine whether life can be sustained in the absence of radiation. From an astrobiological point of view, it is an interesting model for early life on Earth, as well as a representation of life as it could occur in other planetary bodies, e.g., Mars. Ŕ Tinto is an unusual extreme acidic environment due to its size, constant acidic pH, high ıo concentration of heavy metals and high level of microbial diversity. Ŕ Tinto rises in the core of ıo the Iberian Pyritic Belt (IPB), one of the biggest sulfidic ore deposits in the world. Today it is clear that the extreme characteristics of Ŕ Tinto are not due to acid mine drainage resulting ıo from mining activity. To explore the hypothesis that a continuous underground reactor of chemolithotrophic microorganisms thriving in the rich sulfidic minerals of the IPB is responsible for the extreme conditions found in the river, a drilling project has been developed to detect evidence of subsurface microbial activity and potential resources to support these microbial communities in situ from retrieved cores (MARTE project). Preliminary results clearly show that there is an active subsurface geomicrobiology in the Iberian Pyritic Belt associated to places were ground waters intersects the sulfidic ore body.

Quaternary history of the Kiseiba Oasis region, southern Egypt

NASA Astrophysics Data System (ADS)

Maxwell, Ted A.; Haynes, C. Vance; Nicoll, Kathleen; Johnston, Andrew K.; Grant, John A.; Kilani, Ali

2017-12-01

Kiseiba Oasis and depression are located in southern Egypt between the Selima Sand Sheet to the west and the Nile to the east, an important area that hosted Late Cenozoic drainage, Middle Pleistocene lakes, and numerous Paleolithic and Neolithic cultural sites. A synthesis of orbital data, field surveying and near-surface stratigraphy provides new insights into the Quaternary history of this region. Shuttle Imaging Radar data show a complex of fluvial channels that are due to stringers of surficial fluvial lag, subsurface fluvial deposits, and areas of deep alluvium. Three topographic surfaces are described: 1) the Atmur El-Kibeish, above 230 m elevation, which displays a linear pattern of light radar returns, possibly formed from northeast drainage; 2) the Acheulean Surface, at 200 m elevation, that has dark radar patterns resulting from thick alluvium bounded by pebble sand and calcrete strata, and 3) the Kiseiba Surface, below 190 m, that has a complex series of surface and subsurface fluvial and aeolian sediments. Initial drainage from the Early through Middle Pleistocene was to the northeast, which may have lasted through the Last Interglacial. Later reworking of sediments during the Last Glacial Maximum and the Holocene resulted in topographic inversion, with any subsequent local drainage on the Kiseiba Surface to the southwest, towards the Kiseiba Scarp.

Orbital radar studies of paleodrainages in the central Namib Desert

USGS Publications Warehouse

Lancaster, N.; Schaber, G.G.; Teller, J.T.

2000-01-01

Orbital radar images of the central Namib Desert show clearly the extent of relict fluvial deposits associated with former courses of the Tsondab and Kuiseb rivers. South of the Kuiseb River, radar data show the existence of a drainage network developed in calcrete-cemented late Tertiary fluvial deposits. The sand-filled paleovalleys are imaged as radar-dark tones in contrast to the radar-bright interfluves where the calcreted gravels occur. The drainage network developed as a result of local runoff from indurated gravels and channeled surface and subsurface flow to the sites of the many interdune lacustrine deposits found in the area. (C) Elsevier Science Inc., 2000.Orbital radar images of the central Namib Desert show clearly the extent of relict fluvial deposits associated with former courses of the Tsondab and Kuiseb rivers. South of the Kuiseb River, radar data show the existence of a drainage network developed in calcrete-cemented late Tertiary fluvial deposits. The sand-filled paleovalleys are imaged as radar-dark tones in contrast to the radar-bright interfluves where the calcreted gravels occur. The drainage network developed as a result of local runoff from indurated gravels and channeled surface and subsurface flow to the sites of the many interdune lacustrine deposits found in the area.

Watershed models for instructional films

Treesearch

Peter E. Black; Raymond E. Leonard

1970-01-01

Watershed models, with a special sponge material that simulates soil drainage, were used to make an instructional film on subsurface flow and stream flow. Construction of the models and filming techniques are described.

Hydrologic connectivity of geographically isolated wetlands to surface water systems

NASA Astrophysics Data System (ADS)

Creed, I. F.; Ameli, A.

2016-12-01

Hydrologic connectivity of wetlands is poorly characterized and understood. Our inability to quantify this connectivity compromises our understanding of the potential impacts of land use (e.g., wetland drainage) and climate changes on watershed structure, function and water supplies. We develop a computationally efficient physically-based subsurface-surface hydrological model to map both the subsurface and surface hydrologic connectivity of geographically isolated wetlands (i.e., wetlands without surface outlets) and explore the time and length variations in these connections to a river within the Prairie Pothole Region of North America. Despite a high density of geographically isolated wetlands, modeled connections show that these wetlands are not hydrologically isolated. Hydrologic subsurface connectivity differs significantly from surface connectivity in terms of timing and length of connections. Slow subsurface connections between wetlands and the downstream river originate from wetlands throughout the watershed, whereas fast surface connections were limited to large events and originate from wetlands located near the river. Results also suggest that prioritization of protection of wetlands that relies on shortest distance of wetland to the river or surface connections alone can lead to unintended consequences in terms of loss of attending wetland ecosystem functions, services and their benefits to society. This modeling approach provides first ever insight on the nature of geographically isolated wetland subsurface and surface hydrological connections to rivers, and can provide guidance on the development of watershed management and conservation plans (e.g., wetlands drainage/restoration) under different climate and land management scenarios.

Evaluation of pore-water samplers at a drainage ditch, Installation Restoration Site 4, Naval Air Station Corpus Christi, Corpus Christi, Texas, 2005–06

USGS Publications Warehouse

Vroblesky, Don A.; Casey, Clifton C.

2007-01-01

The U.S. Geological Survey, in cooperation with the Naval Facilities Engineering Command Southeast, used innovative sampling methods to investigate ground-water contamination by chlorobenzenes beneath a drainage ditch on the southwestern side of Installation Restoration Site 4, Naval Air Station Corpus Christi, Corpus Christi, Texas, during 2005-06. The drainage ditch, which is a potential receptor for ground-water contaminants from Installation Restoration Site 4, intermittently discharges water to Corpus Christi Bay. This report evaluates a new type of pore-water sampler developed for this investigation to examine the subsurface contamination beneath the drainage ditch. The new type of pore-water sampler appears to be an effective approach for long-term monitoring of ground water in the sand and organic-rich mud beneath the drainage ditch.

KEEPING DUST UNDER THE CARPET

EPA Science Inventory

The paper gives results of a study of civil engineering fabrics applied to fugitive dust problems. The fabrics, commonly used for ground stabilization, subsurface drainage, railroad construction and maintenance, sediment control, and erosion control, are available from Celanese, ...

Continuous Passive Sampling of Solutes from Agricultural Subsurface Drainage Tubes

NASA Astrophysics Data System (ADS)

Lindblad Vendelboe, Anders; de Jonge, Hubert; Rozemeijer, Joachim; Wollesen de Jonge, Lis

2015-04-01

Agricultural subsurface tube drain systems play an important role in water and solute transport. One study, focusing on lowland agricultural catchments, showed that subsurface tube drainage contributed up to 80% of the annual discharge and 90% of the annual NO3 load from agricultural fields to the receiving water bodies. Knowledge of e.g. nutrient loads and drainage volumes, based on measurements and modelling, are important for adequate water quality management. Despite the importance of tube drain transport of solutes, monitoring data are scarce. This scarcity is a result of the existing monitoring techniques for flow and contaminant load from tube drains being expensive and labor-extensive. The study presented here aimed at developing a cheap, simple, and robust method to monitor solute loads from tube drains. The method is based on the newly developed Flowcap, which can be attached to existing tube drain outlets and can measure total flow, contaminant load and flow-averaged concentrations of solutes in the drainage. The Flowcap builds on the existing Sorbicell principle, a passive sampling system that measures average concentrations over longer periods of time (days to months) for various compounds. The Sorbicell consists of two compartments permeable to water. One compartment contains an adsorbent and one contains a tracer. When water passes through the Sorbicell the compound of interest is absorbed while a tracer is released. Using the tracer loss to calculate the volume of water that has passed the Sorbicell it is possible to calculate the average concentration of the compound. When mounting Sorbicells in the Flowcap, a flow-proportional part of the drainage is sampled from the main stream. To accommodate the wide range of drainage flow rates two Flowcaps with different capacities were tested in the laboratory: one with a capacity of 25 L min-1 (Q25) and one with a capacity of 256 L min-1 (Q256). In addition, Sorbicells with two different hydraulic resistances were tested, again to accommodate a large range of potential drainage flows rates. The experiment was continued until the Sorbicell's capacity was exhausted, which gave experimentation times from 6 to 34 days, while continuously changing the drainage flow rate to simulate field drainage conditions, and to test the range of the Flowcap. The laboratory testing yielded a very good linear correlation between drainage flow rates and Sorbicell sampling rates, giving r = 0.99 for both the Q25 and the Q256 Flowcap. The Sorbicells in this experiment were designed to measure NO3, but the Flowcap can be used with any Sorbicell and thus be used to measure any compound of interest. The Flowcap does not need housing, electricity, or maintenance and continuously register drainage volumes and contaminant loads for periods up to one month. This, in addition to the low cost of the monitoring system, enables large-scale monitoring of contaminant loads via tube drains, giving valuable data for the improvement of contaminant transport models. Further, these data will help select and evaluate the different mitigation option to improve water quality.

Effects of cell surface characteristics and manure-application practices on Escherichia coli populations in the subsurface: A three-farm study

NASA Astrophysics Data System (ADS)

Salvucci, A. E.; Elton, M.; Siler, J. D.; Zhang, W.; Richards, B. K.; Geohring, L. D.; Warnick, L. D.; Hay, A. G.; Steenhuis, T.

2010-12-01

The introduction of microbial pathogens into the environment from untreated manure represents a threat to water quality and human health. Thus, understanding the effect of manure management strategies is imperative to effectively mitigate the inadvertent release of pathogens, particularly in subsurface environments where they can be transported through macropores to the groundwater or through agricultural tile line to open water bodies. The production of cell-surface biomolecules is also suspected to play an important role in the environmental survival and transport of enterobacterial pathogens. This study collected Escherichia coli samples from three dairy farms with artificial tile drainage systems and active manure spreading in the Central New York region over a three-month period. Sampling targeted four potential source locations on each farm: (i) cow housing, (ii) manure storage facilities, (iii) field soil, and (iv) subsurface drainage effluent. Over 2800 E. coli isolates were recovered and consequently analyzed for the cell surface components, cellulose and curli, traits associated with increased environmental survival, altered transport and pathogenicity. The E. coli isolates from locations i-iii displayed highly variable curli and cellulose-producing communities, while isolates collected from subsurface runoff on each farm had stable curli and cellulose production communities over all sampling dates. Furthermore, the method of manure application to the fields influenced the population characteristics found in drainage effluent isolates. Incorporation of manure into the soil was correlated to isolate populations largely deficient of curli and cellulose; whereas farms that only surface-applied manure were correlated to isolate populations of high curli and cellulose production. The production of curli and cellulose has previously been shown to be a response to environmental stress on the cell. Therefore, incorporation of manure directly into the soil appears to minimize environmental stresses, like UV radiation, desiccation and temperature fluctuation, typically found on the soil surface. Our findings indicate that E. coli strains above the surface are largely diverse, until they enter subsurface environments where specific extracellular characteristics are likely advantageous for survival and/or transport.

Exploring Agricultural Drainage's Influence on Wetland and ...

EPA Pesticide Factsheets

Artificial agricultural drainage (i.e. surface ditches or subsurface tile) is an important agricultural management tool. Artificial drainage allows for timely fieldwork and adequate root aeration, resulting in greater crop yields for farmers. This practice is widespread throughout many regions of the United States and the network of artificial drainage is especially extensive in flat, poorly-drained regions like the glaciated Midwest. While beneficial for crop yields, agricultural drains often empty into streams within the natural drainage system. The increased network connectivity may lead to greater contributing area for watersheds, altered hydrology and increased conveyance of pollutants into natural water bodies. While studies and models at broader scales have implicated artificial drainage as an important driver of hydrological shifts and eutrophication, the actual spatial extent of artificial drainage is poorly known. Consequently, metrics of wetland and watershed connectivity within agricultural regions often fail to explicitly include artificial drainage. We use recent agricultural census data, soil drainage data, and land cover data to create estimates of potential agricultural drainage across the United States. We estimate that agricultural drainage in the US is greater than 31 million hectares and is concentrated in the upper Midwest Corn Belt, covering greater than 50% of available land for 114 counties. Estimated drainage values for numerous countie

Superfund record of decision (EPA Region 1): Otis Air National Guard (USAF), Operable Unit 5, Falmouth, MA, September 30, 1998

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1999-03-01

This decision document presents the Air Force Center for Environmental Excellence (AFCEE) selected remedial action decisions for contaminant source areas at the following Areas of Contamination (AOCs) at the Massachusetts Military Reservation (MMR) in Barnstable County on Cape Cod, Massachusetts: Fire Training Area No. 2 and Landfill No. 2 (FTA-2/LF-2); Petroleum Fuels Storage Area, Fuel Spill No. 10, and Fuel Spill No. 11 (PFSA/FS-10/FS-11); Storm Drainage Ditch No. 2, Fuel Spill No. 6, and Fuel Spill No. 8 (SD-2/FS-6/FS-8); Storm Drainage Ditch No. 2, Fire Training Area No. 3, and Coal Storage Yard No. 4 (SF-3/FTA-3/CY-4); Storm Drainage Ditch No.more » 4 (SD-4); and Storm Drainage Ditch No. 5 and Fuel Spill No. 5 (SD-5/FS-5). The selected remedy for AOC FTA-2/LF-2 is Biosparging with Ambient Air Monitoring. This remedial action is a source control action that addresses leaching of organic compounds to groundwater, the principal known threat at AOC FTA-2/LF-2. It consists of designing, constructing, and operating a biosparging treatment system, maintaining institutional controls, and five-year reviews of remedy protectiveness. The remedy reduces the release of contaminants from subsurface soils by treating subsurface soils to meet protective cleanup levels.« less

Bacterial contamination of tile drainage water and shallow groundwater under different application methods of liquid swine manure.

PubMed

Samarajeewa, A D; Glasauer, S M; Lauzon, J D; O'Halloran, I P; Parkin, Gary W; Dunfield, K E

2012-05-01

A 2 year field experiment evaluated liquid manure application methods on the movement of manure-borne pathogens (Salmonella sp.) and indicator bacteria (Escherichia coli and Clostridium perfringens) to subsurface water. A combination of application methods including surface application, pre-application tillage, and post-application incorporation were applied in a randomized complete block design on an instrumented field site in spring 2007 and 2008. Tile and shallow groundwater were sampled immediately after manure application and after rainfall events. Bacterial enumeration from water samples showed that the surface-applied manure resulted in the highest concentration of E. coli in tile drainage water. Pre-tillage significantly (p < 0.05) reduced the movement of manure-based E. coli and C. perfringens to tile water and to shallow groundwater within 3 days after manure application (DAM) in 2008 and within 10 DAM in 2007. Pre-tillage also decreased the occurrence of Salmonella sp. in tile water samples. Indicator bacteria and pathogens reached nondetectable levels within 50 DAM. The results suggest that tillage before application of liquid swine manure can minimize the movement of bacteria to tile and groundwater, but is effective only for the drainage events immediately after manure application or initial rainfall-associated drainage flows. Furthermore, the study highlights the strong association between bacterial concentrations in subsurface waters and rainfall timing and volume after manure application.

Modeling Groundwater Flow System of a Drainage Basin in the Basement Complex Environment of Southwestern Nigera

NASA Astrophysics Data System (ADS)

Akinwumiju, Akinola S.; Olorunfemi, Martins O.

2018-05-01

This study attempted to model the groundwater flow system of a drainage basin within the Basement Complex environment of Southwestern Nigeria. Four groundwater models were derived from Vertical Electrical Sounding (VES) Data, remotely sensed data, geological information (hydrolineaments and lithology) and borehole data. Subsequently, two sub-surface (local and regional) flow systems were delineated in the study area. While the local flow system is controlled by surface topography, the regional flow system is controlled by the networks of intermediate and deep seated faults/fractures. The local flow system is characterized by convergence, divergence, inflow and outflow in places, while the regional flow system is dominated by NNE-SSW and W-E flow directions. Minor flow directions include NNW-SSE and E-W with possible linkages to the main flow-paths. The NNE-SSW regional flow system is a double open ended flow system with possible linkage to the Niger Trough. The W-E regional flow system is a single open ended system that originates within the study area (with possible linkage to the NNE-SSW regional flow system) and extends to Ikogosi in the adjoining drainage basin. Thus, the groundwater drainage basin of the study area is much larger and extensive than its surface drainage basin. The all year round flowing (perennial) rivers are linked to groundwater outcrops from faults/fractures and contact zones. Consequently, larger percentage of annual rainwater usually leaves the basin in form of runoff and base flow. Therefore, the basin is categorized as a donor basin but with suspected subsurface water input at its northeastern axis.

Shallow subsurface storm flow in a forested headwater catchment: Observations and modeling using a modified TOPMODEL

USGS Publications Warehouse

Scanlon, Todd M.; Raffensperger, Jeff P.; Hornberger, George M.; Clapp, Roger B.

2000-01-01

Transient, perched water tables in the shallow subsurface are observed at the South Fork Brokenback Run catchment in Shenandoah National Park, Virginia. Crest piezometers installed along a hillslope transect show that the development of saturated conditions in the upper 1.5 m of the subsurface is controlled by total precipitation and antecedent conditions, not precipitation intensity, although soil heterogeneities strongly influence local response. The macroporous subsurface storm flow zone provides a hydrological pathway for rapid runoff generation apart from the underlying groundwater zone, a conceptualization supported by the two‐storage system exhibited by hydrograph recession analysis. A modified version of TOPMODEL is used to simulate the observed catchment dynamics. In this model, generalized topographic index theory is applied to the subsurface storm flow zone to account for logarithmic storm flow recessions, indicative of linearly decreasing transmissivity with depth. Vertical drainage to the groundwater zone is required, and both subsurface reservoirs are considered to contribute to surface saturation.

A multicomponent coupled model of glacier hydrology 1. Theory and synthetic examples

NASA Astrophysics Data System (ADS)

Flowers, Gwenn E.; Clarke, Garry K. C.

2002-11-01

Basal hydrology is acknowledged as a fundamental control on glacier dynamics, especially in cases where surface meltwater reaches the bed. For many glaciers at midlatitudes, basal drainage is influenced by subaerial, englacial, and subsurface water flow. One of the major shortcomings of existing basal hydrology models is the treatment of the glacier bed as an isolated system. We present theoretical and computational models that couple glacier surface runoff, englacial water storage and transport, subglacial drainage, and subsurface groundwater flow. Each of the four model components is represented as a two-dimensional, vertically integrated layer that communicates with its neighbors through water exchange. Governing equations are derived from the law of mass conservation and are expressed as a balance between the internal distribution of water and external sources. The numerical exposition of this theory is a time-dependent finite difference model that can be used to simulate glacier drainage. In this paper we outline the theory and conduct simple tests using an idealized glacier geometry. In the companion paper, the model is tailored to Trapridge Glacier, Yukon Territory, Canada, where results are compared with measurements of subglacial water pressure.

Pathways and transformations of dissolved methane and dissolved inorganic carbon in Arctic tundra watersheds: Evidence from analysis of stable isotopes

DOE PAGES

Throckmorton, Heather M.; Heikoop, Jeffrey M.; Newman, Brent D.; ...

2015-11-08

Arctic soils contain a large pool of terrestrial C and are of interest due to their potential for releasing significant carbon dioxide (CO 2) and methane (CH 4) to the atmosphere. Due to substantial landscape heterogeneity, predicting ecosystem-scale CH 4 and CO 2 production is challenging. This study assessed dissolved inorganic carbon (DIC = Σ (total) dissolved CO 2) and CH 4 in watershed drainages in Barrow, Alaska as critical convergent zones of regional geochemistry, substrates, and nutrients. In July and September of 2013, surface waters and saturated subsurface pore waters were collected from 17 drainages. Based on simultaneous DICmore » and CH 4 cycling, we synthesized isotopic and geochemical methods to develop a subsurface CH 4 and DIC balance by estimating mechanisms of CH 4 and DIC production and transport pathways and oxidation of subsurface CH 4. We observed a shift from acetoclastic (July) toward hydrogenotropic (September) methanogenesis at sites located toward the end of major freshwater drainages, adjacent to salty estuarine waters, suggesting an interesting landscape-scale effect on CH 4 production mechanism. The majority of subsurface CH 4 was transported upward by plant-mediated transport and ebullition, predominantly bypassing the potential for CH 4 oxidation. Thus, surprisingly, CH 4 oxidation only consumed approximately 2.51± 0.82% (July) and 0.79 ± 0.79% (September) of CH 4 produced at the frost table, contributing to <0.1% of DIC production. DIC was primarily produced from respiration, with iron and organic matter serving as likely e- acceptors. Furthermore, this work highlights the importance of spatial and temporal variability of CH 4 production at the watershed scale and suggests broad scale investigations are required to build better regional or pan-Arctic representations of CH 4 and CO 2 production.« less

Effects of underground mining and mine collapse on the hydrology of selected basins in West Virginia

USGS Publications Warehouse

Hobba, William A.

1993-01-01

The effects of underground mining and mine collapse on areal hydrology were determined at one site where the mined bed of coal lies above major streams and at two sites where the bed of coal lies below major streams. Subsidence cracks observed at land surface generally run parallel to predominant joint sets in the rocks. The mining and subsidence cracks increase hydraulic conductivity and interconnection of water-bearing rock units, which in turn cause increased infiltration of precipitation and surface water, decreased evapotranspiration, and higher base flows in some small streams. Water levels in observation wells in mined areas fluctuate as much as 100 ft annually. Both gaining and losing streams are found in mined areas. Mine pumpage and drainage can cause diversion of water underground from one basin to another. Areal and single-well aquifer tests indicated that near-surface rocks have higher transmissivity in a mine-subsided basin than in unmined basins. Increased infiltration and circulation through shallow subsurface rocks increase dissolved mineral loads in streams, as do treated and untreated contributions from mine pumpage and drainage. Abandoned and flooded underground mines make good reservoirs because of their increased transmissivity and storage. Subsidence cracks were not detectable by thermal imagery, but springs and seeps were detectable.

Evaluation of Roadway Subsurface Drainage on Rural Routes

DOT National Transportation Integrated Search

2017-09-01

Excess moisture has been identified as a cause for stripping, raveling, debonding, and rutting in flexible pavement [ODOT, 2016a]. The Ohio Department of Transportation (ODOT) has been getting substantially less than the expected 15 year service life...

Estimating restorable wetland water storage at landscape scales

EPA Science Inventory

Globally, hydrologic modifications such as ditching and subsurface drainage have significantly reduced wetland water storage capacity (i.e., the volume of surface water a wetland can retain) and consequent wetland functions. While wetland area has been well documented across many...

Evaluating roadway subsurface drainage practices.

DOT National Transportation Integrated Search

2013-05-01

The bearing capacity and service life of a pavement is affected adversely by the presence of undrained water in the pavement layers. In cold winter climates like in Iowa, this problem is magnified further by the risk of frost damage when water is pre...

Subsurface drainage for rehabilitation of PCC pavement - Rt. 202 Gray - New Gloucester.

DOT National Transportation Integrated Search

2003-12-01

Many existing roadways are being enhanced due to the pressures of increased vehicular traffic. Some of : these improvements involve widening the present travel way to accommodate a turning lane and/or : additional travel lanes. This often necessitate...

Subsurface phosphorus transport through a no-till field in the semi arid Palouse region

NASA Astrophysics Data System (ADS)

Norby, J. C.; Brooks, E. S.; Strawn, D. G.

2017-12-01

Excess application of fertilizers containing nitrogen and phosphorus for farming use has led to ongoing water quality issues in the United States. When these nutrients leave agronomic systems, and enter water bodies in large quantities, algal bloom and eutrophication can occur. Extensive studies focusing on phosphorus as a pollutant from agronomic systems have been conducted in the many regions of the United States; however, there has been a lack of studies completed in the semiarid Palouse region of eastern Washington and western Idaho. The goal of this research study was to better understand how no-till farm management has altered soil P temporally and the current availability for off-site transport of P throughout an artificially drained catchment at the Cook Agronomy Farm in Pullman, WA. We also attempted to determine the processes responsible for subsurface flow of phosphorus, specifically through preferential flow pathways. Dissolved reactive P (DRP)concentrations of subsurface drainage from a artificial drain exceeded TMDL threshold concentrations during numerous seasonal high flow events over the two-year study time frame. Soil analyses show a highly variable distribution of water-extractable P across the sub-catchment area and initial results suggest a translocation of P species deeper into the soil profile after implementing no-till practices in 1998. We hypothesized that a greater network of macropores from lack of soil disturbance allow for preferential flow of nutrient-laden water deeper into the subsurface and to the artificial drain system. Simulated flow experiments on soil cores from the study site showed large-scale macropore development, extreme variability in soil conductivity, and high P adsorption potential for the soils, suggesting a disconnect between P movement through macropore soil and subsurface drainage water rich in DRP at the artificial drain line outlet.

Evaluating the reliability of the stream tracer approach to characterize stream-subsurface water exchange

USGS Publications Warehouse

Harvey, Judson W.; Wagner, Brian J.; Bencala, Kenneth E.

1996-01-01

Stream water was locally recharged into shallow groundwater flow paths that returned to the stream (hyporheic exchange) in St. Kevin Gulch, a Rocky Mountain stream in Colorado contaminated by acid mine drainage. Two approaches were used to characterize hyporheic exchange: sub-reach-scale measurement of hydraulic heads and hydraulic conductivity to compute streambed fluxes (hydrometric approach) and reachscale modeling of in-stream solute tracer injections to determine characteristic length and timescales of exchange with storage zones (stream tracer approach). Subsurface data were the standard of comparison used to evaluate the reliability of the stream tracer approach to characterize hyporheic exchange. The reach-averaged hyporheic exchange flux (1.5 mL s−1 m−1), determined by hydrometric methods, was largest when stream base flow was low (10 L s−1); hyporheic exchange persisted when base flow was 10-fold higher, decreasing by approximately 30%. Reliability of the stream tracer approach to detect hyporheic exchange was assessed using first-order uncertainty analysis that considered model parameter sensitivity. The stream tracer approach did not reliably characterize hyporheic exchange at high base flow: the model was apparently more sensitive to exchange with surface water storage zones than with the hyporheic zone. At low base flow the stream tracer approach reliably characterized exchange between the stream and gravel streambed (timescale of hours) but was relatively insensitive to slower exchange with deeper alluvium (timescale of tens of hours) that was detected by subsurface measurements. The stream tracer approach was therefore not equally sensitive to all timescales of hyporheic exchange. We conclude that while the stream tracer approach is an efficient means to characterize surface-subsurface exchange, future studies will need to more routinely consider decreasing sensitivities of tracer methods at higher base flow and a potential bias toward characterizing only a fast component of hyporheic exchange. Stream tracer models with multiple rate constants to consider both fast exchange with streambed gravel and slower exchange with deeper alluvium appear to be warranted.

A laboratory study of colloid and solute transport in surface runoff on saturated soil

NASA Astrophysics Data System (ADS)

Yu, Congrong; Gao, Bin; Muñoz-Carpena, Rafael; Tian, Yuan; Wu, Lei; Perez-Ovilla, Oscar

2011-05-01

SummaryColloids in surface runoff may pose risks to the ecosystems not only because some of them (e.g., pathogens) are toxic, but also because they may facilitate the transport of other contaminants. Although many studies have been conducted to explore colloid fate and transport in the environment, current understanding of colloids in surface runoff is still limited. In this study, we conducted a range of laboratory experiments to examine the transport behavior of colloids in a surface runoff system, made of a soil box packed with quartz sand with four soil drainage outlets and one surface flow outlet. A natural clay colloid (kaolinite) and a conservative chemical tracer (bromide) were applied to the system under a simulated rainfall event (64 mm/h). Effluent soil drainage and surface flow samples were collected to determine the breakthrough concentrations of bromide and kaolinite. Under the experimental conditions tested, our results showed that surface runoff dominated the transport processes. As a result, kaolinite and bromide were found more in surface flow than in soil drainage. Comparisons between the breakthrough concentrations of bromide and kaolinite showed that kaolinite had lower mobility than bromide in the subsurface flow (i.e., soil drainage), but behaved almost identical to bromide in the surface runoff. Student's t-test confirmed the difference between kaolinite and bromide in subsurface flow ( p = 0.02). Spearman's test and linear regression analysis, however, showed a strong 1:1 correlation between kaolinite and bromide in surface runoff ( p < 0.0001). Our result indicate that colloids and chemical solutes may behave similarly in overland flow on bare soils with limited drainage when surface runoff dominates the transport processes.

Integration of real time kinematic satellite navigation with ground-penetrating radar surveys

USDA-ARS?s Scientific Manuscript database

Precision agriculture, environmental mapping, and construction benefit from subsurface imaging by revealing the spatial variability of underground features. Features surveyed of agricultural interest are bedrock depth, soil horizon thicknesses, and buried–object features such as drainage pipe. For t...

Denitrifying bioreactors for nitrate removal from tile drained cropland

USDA-ARS?s Scientific Manuscript database

Denitrification bioreactors are a promising technology for mitigation of nitrate-nitrogen (NO3-N) losses in subsurface drainage water. Bioreactors are constructed with carbon substrates, typically wood chips, to provide a substrate for denitrifying microorganisms. Researchers in Iowa found that for ...

Subsurface drainage for rehabilitation of PCC pavement : interim report - fourth year, August 2002.

DOT National Transportation Integrated Search

2002-08-01

Many existing roadways are being enhanced due to the pressures of increased vehicular traffic. Some of : these improvements involve widening the present travel way to accommodate a turning lane and/or : additional travel lanes. This often necessitate...

A study of the relationships between strength, density, permeability, and gradations of aggregate bases.

DOT National Transportation Integrated Search

1978-01-01

Accumulating evidence that inadequate subsurface drainage of some pavements was related to impervious base courses led to an investigation of the influence of low permeability fine materials on the physical characteristics of typical base courses. It...

Evaluating roadway subsurface drainage practices : [summary].

DOT National Transportation Integrated Search

2013-05-01

The bearing capacity and service life of a pavement is adversely affected by the presence of undrained water in the pavement layers. In cold climates like in Iowa, this problem is magnified further by the risk of frost damage when water is present. T...

Simulating the Effects of Drainage and Agriculture on Hydrology and Sediment in the Minnesota River Basin

NASA Astrophysics Data System (ADS)

Downer, C. W.; Pradhan, N. R.; Skahill, B. E.; Banitt, A. M.; Eggers, G.; Pickett, R. E.

2014-12-01

Throughout the Midwest region of the United States, slopes are relatively flat, soils tend to have low permeability, and local water tables are high. In order to make the region suitable for agriculture, farmers have installed extensive networks of ditches to drain off excess surface water and subsurface tiles to lower the water table and remove excess soil water in the root zone that can stress common row crops, such as corn and soybeans. The combination of tiles, ditches, and intensive agricultural land practices radically alters the landscape and hydrology. Within the watershed, tiles have outlets to both the ditch/stream network as well as overland locations, where the tile discharge appears to initiate gullies and exacerbate overland erosion. As part of the Minnesota River Basin Integrated Study we are explicitly simulating the tile and drainage systems in the watershed at multiple scales using the physics-based watershed model GSSHA (Gridded Surface Subsurface Hydrologic Analysis). The tile drainage system is simulated as a network of pipes that collect water from the local water table. Within the watershed, testing of the methods on smaller basins shows the ability of the model to simulate tile flow, however, application at the larger scale is hampered by the computational burden of simulating the flow in the complex tile drain networks that drain the agricultural fields. Modeling indicates the subsurface drains account for approximately 40% of the stream flow in the Seven Mile Creek sub-basin account in the late spring and early summer when the tile is flowing. Preliminary results indicate that agricultural tile drains increase overland erosion in the Seven Mile Creek watershed.

Subsurface cadmium loss from a stony soil-effect of cow urine application.

PubMed

Gray, Colin William; Chrystal, Jane Marie; Monaghan, Ross Martin; Cavanagh, Jo-Anne

2017-05-01

Cadmium (Cd) losses in subsurface flow from stony soils that have received cow urine are potentially important, but poorly understood. This study investigated Cd loss from a soil under a winter dairy-grazed forage crop that was grazed either conventionally (24 h) or with restricted grazing (6 h). This provided an opportunity to test the hypothesis that urine inputs could increase Cd concentrations in drainage. It was thought this would be a result of cow urine either (i) enhancing dissolved organic carbon (DOC) concentrations via an increase in soil pH, resulting in the formation of soluble Cd-organic carbon complexes and, or (ii) greater inputs of chloride (Cl) via cow urine, promoting the formation of soluble Cd-Cl complexes. Cadmium concentrations in subsurface flow were generally low, with a spike above the water quality guidelines for a month after the 24-h grazing. Cadmium fluxes were on average 0.30 g Cd ha -1  year -1 (0.27-0.32 g Cd ha -1  year -1 ), in line with previous estimates for agricultural soils. The mean Cd concentration in drainage from the 24-h grazed plots was significantly higher (P < 0.05) than 6-h plots. No increase in DOC concentrations between the treatments was found. However, Cl concentrations in drainage were significantly higher (P < 0.001) from the 24-h than the 6-h grazed treatment plots, and positively correlated with Cd concentrations, and therefore, a possible mechanism increasing Cd mobility in soil. Further study is warranted to confirm the mechanisms involved and quantities of Cd lost from other systems.

Completion reports, core logs, and hydrogeologic data from wells and piezometers in Prospect Gulch, San Juan County, Colorado

USGS Publications Warehouse

Johnson, Raymond H.; Yager, Douglas B.

2006-01-01

In the late nineteenth century, San Juan County, Colorado, was the center of a metal mining boom in the San Juan Mountains. Although most mining activity ceased by the 1990s, the effects of historical mining continue to contribute metals to ground water and surface water. Previous research by the U.S. Geological Survey identified ground-water discharge as a significant pathway for the loading of metals to surface water from both acid-mine drainage and acid-rock drainage. In an effort to understand the ground-water flow system in the upper Animas River watershed, Prospect Gulch was selected for further study because of the amount of previous data provided in and around that particular watershed. In support of this ground-water research effort, wells and piezometers were installed to allow for coring during installation, subsurface hydrologic testing, and the monitoring of ground-water hydraulic heads and geochemistry. This report summarizes the data that were collected during and after the installation of these wells and piezometers and includes (1) subsurface completion details, (2) locations and elevations, (3) geologic logs and elemental data, (4) slug test data for the estimation of subsurface hydraulic conductives, and (5) hydraulic head data.

After-discovery studies prolong life. [Role of the geologist in oil fields

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hartman, J.A.

1977-05-02

Unless there is a problem, a field may receive little attention by geologists once the primary development phase is over. This is a mistake because analysis of production data may point to areas where more development is needed. In large, multipay fields it is hard to gather the data into a usable form and to attempt to use these data to develop a consistent subsurface interpretation which explains the facts. With wells spaced only a few hundred feet apart, the geologist cannot let his imagination run wild as he can when looking at wildcat country. However, the results obtained frommore » studying oil fields can be very rewarding for both the geologist and his company. For maximum benefit, a subsurface field review should include all facts of the geology, as well as the reservoir, petro-physical, and production engineering aspects. When a field is studied in detail, areas of poor drainage are generally found and those become potential objectives for new wells on recompletions in existing wells. The following are discussed: (1) updip undrained areas; (2) bottom water reservoirs; (3) stringer drainage; and (4) South Pass block 24 field. When a field is studied in detail, unanticipated drainage anomalies are commonly found.« less

Using constructed wetlands to treat subsurface drainage from intensively grazed dairy pastures in New Zealand.

PubMed

Tanner, C C; Nguyen, M Long; Sukias, J P S

2003-01-01

Performance data, during the start-up period, are presented for constructed wetlands treating subsurface drainage from dairy pastures in Waikato (rain-fed) and Northland (irrigated), North Island, New Zealand. The wetlands comprised an estimated 1 and 2% of the drained catchment areas, respectively. Nitrate concentrations were high in the drainage inflows at both sites (medians 10 g m(-3) at Waikato and 6.5 g m(-3) at Northland), but organic N was also an important form of N at Waikato (37% of TN). Comparison of wetland inflow and outflow nutrient concentrations showed overall nutrient reductions during passage through the wetlands for NO3-N (34 and 94% for medians, respectively), TN (56 and 33%, respectively), and DRP (80%, Northland only). Median NH4-N (both sites) and DRP (Waikato) concentrations showed apparent increases between the wetland inlets and outlets. However, a mass balance calculated for the 3 month preliminary monitoring periods showed substantial mass removal of DRP (80%) and all measured forms of N (NO3-N 78%, NH4-N 41%, Org-N 99.8% and TN 96%) in the Waikato wetland. Monitoring of these systems needs to be continued through a range of seasons and years to fully assess their long-term performance.

Installation Restoration Program. Phase I. Records Search, Hazardous Materials Disposal Sites. Myrtle Beach Air Force Base, South Carolina.

DTIC Science & Technology

1981-10-01

Geography 3-1 Topography 3-. Drainage 3-1 ii Page Surface Geology 3-3 Barrier Sediments 3-3 Myrtle Beach Backbarrier Sediments 3-3 soils 3-5 Subsurface...Beach AFB Surface Drainage and Surface Water Sampling Points 3-2 3.2 Myrtle Beach AFB Surface Soils 3-4 3.3 Myrtle Beach AFB Location of Geologic Cross...has created a potential contamination problem. This situation is compounded by the site’s sandy soil and shallow ground water table. b.) Weathering Pit

Optimization of denitrifying bioreactor performance with agricultural residue-based filter media

USDA-ARS?s Scientific Manuscript database

Denitrification bioreactors are a promising technology for mitigation of nitrate-nitrogen (NO3-N) losses in subsurface drainage water. Bioreactors are constructed with carbon substrates, typically wood chips, to provide a substrate for denitrifying microorganisms. Columns were packed with wood chips...

Non-linear hydraulic properties of woodchips necessary to design denitrification beds

USDA-ARS?s Scientific Manuscript database

Denitrification beds are being used to reduce the transport of water-soluble nitrate via subsurface drainage systems to surface water. Only recently has the non-linearity of water flow through woodchips been ascertained. To successfully design and model denitrification beds for optimum nitrate remov...

Organic Carbon as Inhibitor to SVOC and Metal Migration in Stormwater Drywells Discharging to the Subsurface-SLIDES

EPA Science Inventory

The Safe Drinking Water Act (SDWA) authorizes the Underground Injection Control (UIC) program to protect underground drinking water (USDW) sources from contamination caused by underground injection wells, including regulation of stormwater drainage drywells for parking lot and ro...

Profiling USGA putting greens using GPR - an as-built surveying method

USDA-ARS?s Scientific Manuscript database

Putting greens installed using the United States Golf Association (USGS) specifications have a subsurface infrastructure constructed to exacting standards. It may be difficult to discern those drainage systems that possess installation flaws, as some flaws may not be readily obvious as their being ...

Can we treat enough water to meet water quality goals

USDA-ARS?s Scientific Manuscript database

Denitrifying woodchip bioreactors are sized to treat a portion of subsurface drainage flow from a given system. Over sizing them can create conditions under which unintended consequences could occur. A potential solution for treating additional water is to use a cascading series of bioreactor cell...

Woodchip denitrification bioreactors: Impact of temperature and hydraulic retention time on nitrate removal

USDA-ARS?s Scientific Manuscript database

Woodchip denitrification bioreactors, a relatively new technology for edge-of-field treatment of subsurface agricultural drainage water, have shown potential for nitrate removal. However, very few studies have evaluated the performance of these reactors under controlled conditions similar to the fie...

40 CFR Appendix D to Part 300 - Appropriate Actions and Methods of Remedying Releases

Code of Federal Regulations, 2013 CFR

2013-07-01

...) Neutralization. (D) Equalization. (E) Chemical oxidation. (iii) Physical methods, including the following: (A... treatment. (F) Wet air oxidation. (G) Solidification. (H) Encapsulation. (I) Soil washing or flushing. (J... containment. (iv) Leachate control, including the following: (A) Subsurface drains. (B) Drainage ditches. (C...

40 CFR Appendix D to Part 300 - Appropriate Actions and Methods of Remedying Releases

Code of Federal Regulations, 2014 CFR

2014-07-01

...) Neutralization. (D) Equalization. (E) Chemical oxidation. (iii) Physical methods, including the following: (A... treatment. (F) Wet air oxidation. (G) Solidification. (H) Encapsulation. (I) Soil washing or flushing. (J... containment. (iv) Leachate control, including the following: (A) Subsurface drains. (B) Drainage ditches. (C...

40 CFR Appendix D to Part 300 - Appropriate Actions and Methods of Remedying Releases

Code of Federal Regulations, 2012 CFR

2012-07-01

...) Neutralization. (D) Equalization. (E) Chemical oxidation. (iii) Physical methods, including the following: (A... treatment. (F) Wet air oxidation. (G) Solidification. (H) Encapsulation. (I) Soil washing or flushing. (J... containment. (iv) Leachate control, including the following: (A) Subsurface drains. (B) Drainage ditches. (C...

Managing phosphorus export from golf courses using industrial byproducts as filter materials

USDA-ARS?s Scientific Manuscript database

Golf courses, and in particular the tees, fairways, and putting greens, are vulnerable to loss of phosphorus (P) as dissolved reactive P (DRP) through sandy, porous grass rooting media and subsurface tile drainage. Excess levels of phosphorus (P) in surface waters promotes eutrophication, which in t...

Identifying riparian zones appropriate for installation of saturated buffers: A multi-watershed assessment

USDA-ARS?s Scientific Manuscript database

Saturated riparian buffers are a new type of conservation practice that divert a portion of subsurface tile drainage from discharge to surface water into distribution pipes that discharge tile water into riparian soils. This enables natural processes of biological uptake and denitrification to decre...

Effectiveness of conservation practices within watersheds: Case study in tile-drained systems

USDA-ARS?s Scientific Manuscript database

The effectiveness of conservation practices are governed in part by the spatial and temporal patterns of water flow as runoff and subsurface (tile) drainage. The variability in patterns of nitrate loss were examined using data from different sized catchments with four CEAP watersheds located in cent...

Comparison of contaminant transport in agricultural drainage water and urban stormwater runoff

USDA-ARS?s Scientific Manuscript database

Transport of nitrogen and phosphorus from agricultural and urban landscapes to surface water bodies can cause adverse environmental impacts including hypoxia and harmful algal blooms. The main objective of this long-term study was to quantify and compare contaminant transport from a subsurface-drain...

Seasonal variation of macrolide resistance gene abundances in the South Fork Iowa River Watershed

USDA-ARS?s Scientific Manuscript database

The Midwestern United States is dominated by agricultural production with high concentrations of swine, leading to application of swine manure onto lands with artificial subsurface drainage. Previous reports have indicated elevated levels of antibiotic resistance genes (ARGs) in surface water and gr...

Assessment of Subsurface Drainage Management Practices to Reduce Nitrogen Loadings Using AnnAGNPS

EPA Science Inventory

The goal of the Future Midwest Landscape project is to quantify current and future landscape services across the region and examine changes expected to occur as a result of two alternative drivers of future change: the growing demand for biofuels; and hypothetical increases in in...

Biochar-amended filter socks reduce herbicide losses via tile line surface inlets

USDA-ARS?s Scientific Manuscript database

Standing water in depressions and behind terraces in fields with subsurface drainage systems can result in reduced crop yields. This concern can be partially alleviated by installing surface inlets that reduce the duration of ponding. Unfortunately, these inlets provide an open conduit for surface w...

Tile Drainage Density Reduces Groundwater Travel Times and Compromises Riparian Buffer Effectiveness.

PubMed

Schilling, Keith E; Wolter, Calvin F; Isenhart, Thomas M; Schultz, Richard C

2015-11-01

Strategies to reduce nitrate-nitrogen (nitrate) pollution delivered to streams often seek to increase groundwater residence time to achieve measureable results, yet the effects of tile drainage on residence time have not been well documented. In this study, we used a geographic information system groundwater travel time model to quantify the effects of artificial subsurface drainage on groundwater travel times in the 7443-ha Bear Creek watershed in north-central Iowa. Our objectives were to evaluate how mean groundwater travel times changed with increasing drainage intensity and to assess how tile drainage density reduces groundwater contributions to riparian buffers. Results indicate that mean groundwater travel times are reduced with increasing degrees of tile drainage. Mean groundwater travel times decreased from 5.6 to 1.1 yr, with drainage densities ranging from 0.005 m (7.6 mi) to 0.04 m (62 mi), respectively. Model simulations indicate that mean travel times with tile drainage are more than 150 times faster than those that existed before settlement. With intensive drainage, less than 2% of the groundwater in the basin appears to flow through a perennial stream buffer, thereby reducing the effectiveness of this practice to reduce stream nitrate loads. Hence, strategies, such as reconnecting tile drainage to buffers, are promising because they increase groundwater residence times in tile-drained watersheds. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Effects of spatial configuration of imperviousness and green infrastructure networks on hydrologic response in a residential sewershed

NASA Astrophysics Data System (ADS)

Lim, Theodore C.; Welty, Claire

2017-09-01

Green infrastructure (GI) is an approach to stormwater management that promotes natural processes of infiltration and evapotranspiration, reducing surface runoff to conventional stormwater drainage infrastructure. As more urban areas incorporate GI into their stormwater management plans, greater understanding is needed on the effects of spatial configuration of GI networks on hydrological performance, especially in the context of potential subsurface and lateral interactions between distributed facilities. In this research, we apply a three-dimensional, coupled surface-subsurface, land-atmosphere model, ParFlow.CLM, to a residential urban sewershed in Washington DC that was retrofitted with a network of GI installations between 2009 and 2015. The model was used to test nine additional GI and imperviousness spatial network configurations for the site and was compared with monitored pipe-flow data. Results from the simulations show that GI located in higher flow-accumulation areas of the site intercepted more surface runoff, even during wetter and multiday events. However, a comparison of the differences between scenarios and levels of variation and noise in monitored data suggests that the differences would only be detectable between the most and least optimal GI/imperviousness configurations.

Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: Artificial Drainage (1992) and Irrigation (1997)

USGS Publications Warehouse

Wieczorek, Michael; LaMotte, Andrew E.

2010-01-01

This tabular data set represents the estimated area of artifical drainage for the year 1992 and irrigation types for the year 1997 compiled for every MRB_E2RF1 catchment of Major River Basins (MRBs, Crawford and others, 2006). The source data sets were derived from tabular National Resource Inventory (NRI) data sets created by the National Resources Conservation Service (NRCS, U.S. Department of Agriculture, 1995, 2000). Artificial drainage is defined as subsurface drains and ditches. Irrigation types are defined as gravity and pressure. Subsurface drains are described as conduits, such as corrugated plastic tubing, tile, or pipe, installed beneath the ground surface to collect and/or convey drainage. Surface drainage field ditches are described as graded ditches for collecting excess water. Gravity irrigation source is described as irrigation delivered to the farm and/or field by canals or pipelines open to the atmosphere; and water is distributed by the force of gravity down the field by: (1) A surface irrigation system (border, basin, furrow, corrugation, wild flooding, etc.) or (2) Sub-surface irrigation pipelines or ditches. Pressure irrigation source is described as irrigation delivered to the farm and/or field in pump or elevation-induced pressure pipelines, and water is distributed across the field by: (1) Sprinkle irrigation (center pivot, linear move, traveling gun, side roll, hand move, big gun, or fixed set sprinklers), or (2) Micro irrigation (drip emitters, continuous tube bubblers, micro spray or micro sprinklers). NRI data do not include Federal lands and are thus excluded from this dataset. The tabular data for drainage were spatially apportioned to the National Land Cover Dataset (NLCD, Kerie Hitt, U.S. Geological Survey, written commun., 2005) and the tabular data for irrigation were spatially apportioned to an enhanced version of the National Land Cover Dataset (NLCDe, Nakagaki and others, 2007). The MRB_E2RF1 catchments are based on a modified version of the U.S. Environmental Protection Agency's (USEPA) ERF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002; Brakebill and others, 2011). Data were compiled for every MRB_E2RF1 catchment for the conterminous United States covering New England and Mid-Atlantic (MRB1), South Atlantic-Gulf and Tennessee (MRB2), the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy (MRB3), the Missouri (MRB4), the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf (MRB5), the Rio Grande, Colorado, and the Great basin (MRB6), the Pacific Northwest (MRB7) river basins, and California (MRB8).

Winter Cover Crop Effects on Nitrate Leaching in Subsurface Drainage as Simulated by RZWQM-DSSAT

NASA Astrophysics Data System (ADS)

Malone, R. W.; Chu, X.; Ma, L.; Li, L.; Kaspar, T.; Jaynes, D.; Saseendran, S. A.; Thorp, K.; Yu, Q.

2007-12-01

Planting winter cover crops such as winter rye (Secale cereale L.) after corn and soybean harvest is one of the more promising practices to reduce nitrate loss to streams from tile drainage systems without negatively affecting production. Because availability of replicated tile-drained field data is limited and because use of cover crops to reduce nitrate loss has only been tested over a few years with limited environmental and management conditions, estimating the impacts of cover crops under the range of expected conditions is difficult. If properly tested against observed data, models can objectively estimate the relative effects of different weather conditions and agronomic practices (e.g., various N fertilizer application rates in conjunction with winter cover crops). In this study, an optimized winter wheat cover crop growth component was integrated into the calibrated RZWQM-DSSAT hybrid model and then we compare the observed and simulated effects of a winter cover crop on nitrate leaching losses in subsurface drainage water for a corn-soybean rotation with N fertilizer application rates over 225 kg N ha-1 in corn years. Annual observed and simulated flow-weighted average nitrate concentration (FWANC) in drainage from 2002 to 2005 for the cover crop treatments (CC) were 8.7 and 9.3 mg L-1 compared to 21.3 and 18.2 mg L-1 for no cover crop (CON). The resulting observed and simulated FWANC reductions due to CC were 59% and 49%. Simulations with the optimized model at various N fertilizer rates resulted in average annual drainage N loss differences between CC and CON to increase exponentially from 12 to 34 kg N ha-1 for rates of 11 to 261 kg N ha-1. The results suggest that RZWQM-DSSAT is a promising tool to estimate the relative effects of a winter crop under different conditions on nitrate loss in tile drains and that a winter cover crop can effectively reduce nitrate losses over a range of N fertilizer levels.

Mechanisms of surface runoff genesis on a subsurface drained soil affected by surface crusting: A field investigation

NASA Astrophysics Data System (ADS)

Augeard, Bénédicte; Kao, Cyril; Chaumont, Cédric; Vauclin, Michel

Artificial drainage has been subject to widespread criticism because of its impact on water quality and because there is suspicion that it may have detrimental effects on flood genesis. The present work aims at a better understanding of the mechanisms controlling infiltration and surface runoff genesis, particularly in soils with artificial drainage and affected by surface crusting. A field experiment was conducted during one drainage season (November 2003-March 2004) in the Brie region (80 km east of Paris, France) on a subsurface drained silty soil. Water table elevation and surface runoff were monitored above the drain and at midpoint between drains. Soil water pressure head was measured at various depths and locations between the midpoint and the drain. Soil surface characteristics (microtopography and degree of structural and sedimentary crust development) were recorded regularly on the experimental site and on other plots of various drainage intensities. The results show that the first surface runoff events were induced by high water table. However, runoff was higher at midpoint between the drains because water table reached the soil surface at that point, thus considerably reducing infiltration capacity compared to that above the drain. Comparing different plots, the area with older drainage installation (1948) yielded the most surface runoff. Wider drain spacing, smaller drain depth and possible plugging may have led to a greater area of saturated soil between drains. During the winter period, the impact of raindrops induced the formation of a structural crust on the soil surface. Furthermore, the development of the sedimentary crust, which was favored by water actually flowing on the soil surface during the high water table periods could be correlated with surface runoff volume. The formation of this crust had a significant impact on runoff occurrence at the end of the winter. Therefore, poorly drained fields presented more favorable conditions for both Horton type runoff and saturation excess runoff. Drainage effectively reduces surface runoff occurrences not only by lowering the water table in winter but also by limiting soil surface sealing.

Pesticide leaching via subsurface drains in different hydrologic situations

NASA Astrophysics Data System (ADS)

Zajíček, Antonín; Fučík, Petr; Liška, Marek; Dobiáš, Jakub

2017-04-01

esticides and their degradates in tile drainage waters were studied in two small, predominantly agricultural, tile-drained subcatchments in the Bohemian-Moravian Highlands, Czech Republic. The goal was to evaluate their occurence and the dymamics of their concentrations in drainage waters in different hydrologic situations using discharge and concentration monitoring together with 18O and 2H isotope analysis for Mean Residence Time (MRT) estimation and hydrograph separations during rainfall - runoff (R-R) events. The drainage and stream discharges were measured continuously at the closing outlets of three drainage groups and one small stream. During periods of prevailing base and interflow, samples were collected manually in two-week intervals for isotope analysis and during the spraying period (March to October) also for pesticide analysis. During R-R events, samples were taken by automatic samplers in intervals varying from 20 min (summer) to 1 hour (winter). To enable isotopic analysis, precipitation was sampled both manually at two-week intervals and also using an automatic rainfall sampler which collected samples of precipitation during the R-R events at 20-min. intervals. The isotopic analysis showed, that MRT of drainage base flow and interflow varies from 2,2 to 3,3 years, while MRT of base flow and interflow in surface stream is several months. During R-R events, the proportion of event water varied from 0 to 60 % in both drainage and surface runoff. The occurrence of pesticides and their degradates in drainage waters is strongly dependent on the hydrologic situation. While degradates were permanently present in drainage waters in high but varying concentrations according to instantaneous runoff composition, parent matters were detected almost exclusively during R-R events. In periods with prevailing base flow and interflow (grab samples), especially ESA forms of chloracetanilide degradates occured in high concentrations in all samples. Average sum of degradates varried between 1 730 - 5 760 ng/l. During R-R events, pesticide concentration varried according to runoff composition and time between sprayng and event. Event with no protortiom of event water in drainage runoff were typical by incereas in degradates concentrations (up to 20 000ng/l) and none or low occurence of parent matters. Events with significant event water proportion in drainage runoff were characterised by decrease in degradates concentrations and (when event happened soon affter spraying) by presence of paternal pesticides in drinage runoff. Instanteous concentrations of paren matters can be extremely high in that causes, up to 23 000 ng/l in drainage waters and up to 40 000 ng/l in small stream. Above results suggest that drainage systems could act as significant source of pesticide leaching. When parent compounds leaches via tile drainage systems, there are some border conditions that must exist together such as the occurence of R-R event soon after the pests application and the presence of event water (or water with short residence time in the catchment) in the drainage runoff.

Spatial and temporal patterns of pesticide losses in a small Swedish agricultural catchment

NASA Astrophysics Data System (ADS)

Sandin, Maria; Piikki, Kristin; Jarvis, Nicholas; Larsbo, Mats; Bishop, Kevin; Kreuger, Jenny

2017-04-01

Research at catchment and regional scales shows that losses of pesticides to surface water often originate from a relatively small fraction of the agricultural landscape. These 'hydrologic source areas' represent areas of land that are highly susceptible to fast transport processes, primarily surface runoff or rapid subsurface flows through soil macropores, either to subsurface field drainage systems or as shallow interflow on more strongly sloping land. A good understanding of the nature of transport pathways for pesticides to surface water in agricultural landscapes is essential for cost-effective identification and implementation of mitigation measures. However, the relative importance of surface and subsurface flows for transport of pesticides to surface waters in Sweden remains largely unknown, since very few studies have been performed under Swedish agro-environmental conditions. We conducted a monitoring study in a small sub-surface drained agricultural catchment in one of the main crop production regions in Sweden. Three small sub-catchments were selected for water sampling based on a high-resolution soil map developed from proximal sensing data; one sub-catchment was dominated by clay soils, another by coarse sandy soils while the third comprised a mix of soil types. Samples were collected from the stream, from field drains discharging into the stream and from within-field surface runoff during spring and early summer in three consecutive years. LC-MS/MS analyses of more than 100 compounds, covering the majority of the polar and semi-polar pesticides most frequently used in Swedish agriculture, were performed on all samples using accredited methods. Information on pesticide applications (products, doses and timing) was obtained from annual interviews with the farmers. There were clear and consistent differences in pesticide losses between the three sub-catchments, with the largest losses occurring in the area with clay soils, and negligible losses from the sandy sub-catchment. This suggests that transport of pesticides to the stream is almost entirely occurring along fast flow paths such as macropore flow to drains or surface runoff. Only a very small proportion of fields are directly connected to the stream by overland pathways, which suggests that macropore flow to drains was the dominant loss pathway in the studied area. Data on pesticide use patterns revealed that compounds were detected in drainage and stream water samples that had not been applied for several years. This suggests that despite the predominant role of fast flow paths in determining losses to the stream, long-term storage along the transport pathways also occurs, presumably in subsoil where degradation is slow.

Tile drainage as karst: Conduit flow and diffuse flow in a tile-drained watershed

USGS Publications Warehouse

Schilling, K.E.; Helmers, M.

2008-01-01

The similarity of tiled-drained watersheds to karst drainage basins can be used to improve understanding of watershed-scale nutrient losses from subsurface tile drainage networks. In this study, short-term variations in discharge and chemistry were examined from a tile outlet collecting subsurface tile flow from a 963 ha agricultural watershed. Study objectives were to apply analytical techniques from karst springs to tile discharge to evaluate water sources and estimate the loads of agricultural pollutants discharged from the tile with conduit, intermediate and diffuse flow regimes. A two-member mixing model using nitrate, chloride and specific conductance was used to distinguish rainwater versus groundwater inputs. Results indicated that groundwater comprised 75% of the discharge for a three-day storm period and rainwater was primarily concentrated during the hydrograph peak. A contrasting pattern of solute concentrations and export loads was observed in tile flow. During base flow periods, tile flow consisted of diffuse flow from groundwater sources and contained elevated levels of nitrate, chloride and specific conductance. During storm events, suspended solids and pollutants adhered to soil surfaces (phosphorus, ammonium and organic nitrogen) were concentrated and discharged during the rapid, conduit flow portion of the hydrograph. During a three-day period, conduit flow occurred for 5.6% of the time but accounted for 16.5% of the total flow. Nitrate and chloride were delivered primarily with diffuse flow (more than 70%), whereas 80-94% of total suspended sediment, phosphorus and ammonium were exported with conduit and intermediate flow regimes. Understanding the water sources contributing to tile drainage and the manner by which pollutant discharge occurs from these systems (conduit, intermediate or diffuse flow) may be useful for designing, implementing and evaluating non-point source reduction strategies in tile-drained landscapes. ?? 2007 Elsevier B.V. All rights reserved.

Nitrate loss in subsurface drainage and corn yield as affected by timing of sidedress nitrogen

USDA-ARS?s Scientific Manuscript database

Using chlorophyll meters, crop sensors, or aerial photography to fine-tune sidedress N application rates have been proposed for optimizing and perhaps reducing overall N fertilizer use on corn (Zea mays L.) and thereby improving water quality by reducing NO3 losses to surface and ground waters. Howe...

Effect of tillage on macropore flow and phosphorus transport to tile drains

USDA-ARS?s Scientific Manuscript database

Elevated phosphorus (P) concentrations in subsurface drainage water are thought to be the result of P bypassing the soil matrix via macropore flow. The objectives of this study were to quantify event water delivery to tile drains via macropore flow paths during storm events and to determine the effe...

Hillslope hydrology research at Caspar Creek

Treesearch

Elizabeth T. Keppeler; Peter H. Cafferata

1991-01-01

As part of the ongoing Caspar Creek Watershed Study on Jackson Demonstration State Forest, researchers from the US Forest Service and the California Department of Forestry and Fire Protection are investigating subsurface drainage in the headwaters of the basin. In order to predict how land use practices will impact stream systems, and hence habitats for aquatic...

Seasonal Patterns in Microbial Community Composition in Denitrifying Bioreactors Treating Subsurface Agricultural Drainage.

PubMed

Porter, Matthew D; Andrus, J Malia; Bartolerio, Nicholas A; Rodriguez, Luis F; Zhang, Yuanhui; Zilles, Julie L; Kent, Angela D

2015-10-01

Denitrifying bioreactors, consisting of water flow control structures and a woodchip-filled trench, are a promising approach for removing nitrate from agricultural subsurface or tile drainage systems. To better understand the seasonal dynamics and the ecological drivers of the microbial communities responsible for denitrification in these bioreactors, we employed microbial community "fingerprinting" techniques in a time-series examination of three denitrifying bioreactors over 2 years, looking at bacteria, fungi, and the denitrifier functional group responsible for the final step of complete denitrification. Our analysis revealed that microbial community composition responds to depth and seasonal variation in moisture content and inundation of the bioreactor media, as well as temperature. Using a geostatistical analysis approach, we observed recurring temporal patterns in bacterial and denitrifying bacterial community composition in these bioreactors, consistent with annual cycling. The fungal communities were more stable, having longer temporal autocorrelations, and did not show significant annual cycling. These results suggest a recurring seasonal cycle in the denitrifying bioreactor microbial community, likely due to seasonal variation in moisture content.

The Role of Interdisciplinary Earth Science in the Assessment of Regional Land Subsidence Hazards: Toward Sustainable Management of Global Land and Subsurface-Fluid Resources

NASA Astrophysics Data System (ADS)

Galloway, D. L.

2012-12-01

Land-level lowering or land subsidence is a consequence of many local- and regional-scale physical, chemical or biologic processes affecting soils and geologic materials. The principal processes can be natural or anthropogenic, and include consolidation or compaction, karst or pseudokarst, hydrocompaction of collapsible soils, mining, oxidation of organic soils, erosive piping, tectonism, and volcanism. In terms of affected area, there are two principal regional-scale anthropogenic processes—compaction of compressible subsurface materials owing to the extraction of subsurface fluids (principally groundwater, oil and gas) and oxidation and compaction accompanying drainage of organic soils—which cause significant hazards related to flooding and infrastructure damage that are amenable to resource management measures. The importance of even small magnitude (< 10 mm/yr) subsidence rates in coastal areas is amplified by its contribution to relative sea-level rise compared to estimated rates of rising eustatic sea levels (2-3 mm/yr) attributed to global climate change. Multi- or interdisciplinary [scientific] studies, including those focused on geodetic, geologic, geophysical, hydrologic, hydrogeologic, geomechanical, geochemical, and biologic factors, improve understanding of these subsidence processes. Examples include geodetic measurement and analysis techniques, such as Global Positioning System (GPS), Light Detection and Ranging (LiDAR) and Interferometric Synthetic Aperture Radar (InSAR), which have advanced our capabilities to detect, measure and monitor land-surface motion at multiple scales. Improved means for simulating aquifer-system and hydrocarbon-reservoir deformation, and the oxidation and compaction of organic soils are leading to refined predictive capabilities. The role of interdisciplinary earth science in improving the characterization of land subsidence attributed to subsurface fluid withdrawals and the oxidation and compaction of organic soils is examined. How these improved capabilities are translating into improved sustainable management of regional land and water resources in a few select areas worldwide are presented. The importance of incorporating these improved capabilities in coherent resource management strategies to control the depletion of resources and attendant hazards also are discussed.

Numerical simulation of water flow and Nitrate transport through variably saturated porous media in laboratory condition using HYDRUS 2D

NASA Astrophysics Data System (ADS)

Jahangeer, F.; Gupta, P. K.; Yadav, B. K.

2017-12-01

Due to the reducing availability of water resources and the growing competition for water between residential, industrial, and agricultural users, increasing irrigation efficiency, by several methods like drip irrigation, is a demanding concern for agricultural experts. The understanding of the water and contaminants flow through the subsurface is needed for the sustainable irrigation water management, pollution assessment, polluted site remediation and groundwater recharge. In this study, the Windows-based computer software package HYDRUS-2D, which numerically simulates water and solute movement in two-dimensional, variably-saturated porous media, was used to evaluate the distribution of water and Nitrate in the sand tank. The laboratory and simulation experiments were conducted to evaluate the role of drainage, recharge flux, and infiltration on subsurface flow condition and subsequently, on nitrate movement in the subsurface. The water flow in the unsaturated zone model by Richards' equation, which was highly nonlinear and its parameters were largely dependent on the moisture content and pressure head of the partially saturated zone. Following different cases to be considered to evaluate- a) applying drainage and recharge flux to study domains, b) transient infiltration in a vertical soil column and c) subsequently, nitrate transport in 2D sand tank setup. A single porosity model was used for the simulation of water and nitrate flow in the study domain. The results indicate the transient water table position decreases as the time increase significantly by applying drainage flux at the bottom. Similarly, the water table positions in study domains increasing in the domain by applying recharge flux. Likewise, the water flow profile shows the decreasing water table elevation with increasing water content in the vertical domain. Moreover, the nitrate movement was dominated by advective flux and highly affected by the recharge flux in the vertical direction. The findings of the study help to enhance the understanding of the sustainable soil-water resources management and agricultural practices.

Dry Stream Reaches in Carbonate Terranes: Surface Indicators of Ground-Water Reservoirs

USGS Publications Warehouse

Brahana, J.V.; Hollyday, E.F.

1988-01-01

In areas where dry stream reaches occur, subsurface drainage successfully competes with surface drainage, and sheet-like dissolution openings have developed parallel to bedding creating the ground-water reservoir. Union Hollow in south-central Tennessee is the setting for a case study that illustrates the application of the dry stream reach technique. In this technique, dry stream reach identification is based on two types of readily acquired information: remotely sensed black and white infrared aerial photography; and surface reconnaissance of stream channel characteristics. Test drilling in Union Hollow subsequent to identification of the dry reach proved that a localized ground-water reservoir was present.

Nitrate concentration-drainage flow (C-Q) relationship for a drained agricultural field in Eastern North Carolina Plain

NASA Astrophysics Data System (ADS)

Liu, W.; Youssef, M.; Birgand, F.; Chescheir, G. M.; Maxwell, B.; Tian, S.

2017-12-01

Agricultural drainage is a practice used to artificially enhance drainage characteristics of naturally poorly drained soils via subsurface drain tubing or open-ditch systems. Approximately 25% of the U.S. agricultural land requires improved drainage for economic crop production. However, drainage increases the transport of dissolved agricultural chemicals, particularly nitrates to downstream surface waters. Nutrient export from artificially drained agricultural landscapes has been identified as the leading source of elevated nutrient levels in major surface water bodies in the U.S. Controlled drainage has long been practiced to reduce nitrogen export from agricultural fields to downstream receiving waters. It has been hypothesized that controlled drainage reduces nitrogen losses by promoting denitrification, reducing drainage outflow from the field, and increasing plant uptake. The documented performance of the practice was widely variable as it depends on several site-specific factors. The goal of this research was to utilize high frequency measurements to investigate the effect of agricultural drainage and related management practices on nitrate fate and transport for an artificially drained agricultural field in eastern North Carolina. We deployed a field spectrophotometer to measure nitrate concentration every 45 minutes and measured drainage flow rate using a V-notch weir every 15 minutes. Furthermore, we measured groundwater level, precipitation, irrigation amount, temperature to characterize antecedent conditions for each event. Nitrate concentration-drainage flow (C-Q) relationships generated from the high frequency measurements illustrated anti-clockwise hysteresis loops and nitrate flushing mechanism in response to most precipitation and irrigation events. Statistical evaluation will be carried out for the C-Q relationships. The results of our analysis, combined with numerical modeling, will provide a better understanding of hydrological and biogeochemical processes controlling the fate and transport of nitrate in drained agricultural landscapes.

Cumulative effects of wetland drainage on watershed-scale subsurface hydrologic connectivity

NASA Astrophysics Data System (ADS)

Creed, I. F.; Ameli, A.

2017-12-01

Subsurface hydrologic connectivity influences hydrological, biogeochemical and ecological responses within watersheds. However, information about the location, duration, and frequency of subsurface hydrologic connections within wetlandscapes and between wetlandscapes and streams is often not available. This leads to a lack of understanding of the potential effects of human modifications of the landscape, including wetland degradation and removal, on subsurface hydrologic connectivity and therefore watershed responses. Herein, we develop a computationally efficient, physically-based subsurface hydrologic connectivity model that explicitly characterizes the effects of wetland degradation and removal on the distribution, length, and timing of subsurface hydrologic connectivity within a wetland-dominated watershed in the Prairie Pothole Region of North America. We run the model using a time series of wetland inventories that reflect incremental wetland loss from 1962, to 1993, and to 2009. We also consider a potential future wetland loss scenario based on removal of all wetlands outside of the protected areas of the watershed. Our findings suggest that wetland degradation and removal over this period increased the average length, transit time, and frequency of subsurface hydrologic connections to the regional surface waters, resulting in decreased baseflow in the major river network. This study provides important insights that can be used by wetland managers and policy makers to support watershed-scale wetland protection and restoration plans to improve water resource management.

Effects of tillage and application rate on atrazine transport to subsurface drainage: Evaluation of RZWQM using a six-year field study

USDA-ARS?s Scientific Manuscript database

Well-tested agricultural system models can improve our understanding of the water quality effects of management practices under different conditions. The Root Zone Water Quality Model (RZWQM) has been tested under a variety of conditions. However, the current model’s ability to simulate pesticide tr...

Dynamics of nitrate and chloride during storm events in agricultural catchments with different subsurface drainage intensity (Indiana, USA)

USDA-ARS?s Scientific Manuscript database

Grids of perforated pipe buried beneath many poorly drained agricultural fields in the Midwestern U.S. are believed to “short circuit” pools of nitrate-laden soil water and shallow groundwater directly into streams that eventually discharge to the Mississippi River. Although much is known about the ...

Irrigated agriculture and freshwater wetlands: A struggle for coexistence in the western United States

Treesearch

A. Dennis Lemly

1994-01-01

This paper is a review of the major environmental problems associated with irrigated agriculture in the western United States. Freshwater wetlands are being contaminated by subsurface agricultural irrigation drainage in many locations. Historic freshwater inflows have been diverted for agricultural use, and remain- ing freshwater supplies are not sufficient to maintain...

Streamflow characteristics of a naturally drained forested watershed in southeast Atlantic coastal plain

Treesearch

Devendra M. Amatya; Carl C. Trettin

2010-01-01

Information about streamflow characteristics e.g. runoff-rainfall (R/O) ratio, rate and timing of flow, surface and subsurface drainage (SSD), and response time to rainfall events is necessary to accurately simulate fluxes and for designing best management practices (BMPs). Unfortunately, those data are scarce in the southeastern Atlantic coastal plain, a highly...

Subsurface pipeflow dynamics of north-coastal California swale systems

Treesearch

Robert R. Ziemer; Jeffrey S. Albright

1987-01-01

Abstract - Pipeflow dynamics are being studied at Caspar Creek Experimental Watershed in north-coastal California near Ft. Bragg. Pipes have been observed at depths to 2 m within trenched swales and at the heads of gullied channels in small (0.8 to 2 ha) headwater drainages. Digital data loggers connected to pressure transducers monitor discharge using calibrated...

The Revival of a Failed Constructed Wetland Treating of a High Fe Load AMD

Treesearch

A.D. Karathanasis; C.D. Barton

1999-01-01

Acid mine drainage (AMD) from abandoned mines has significantly impaired water quality in eastern Kentucky. A small surface flow wetland constructed in 1989 to reduce AMD effects and subsequently failed after six months of operation was renovated by incorporating anoxic limestone drains (ALDs) and anaerobic subsurface drains promoting vertical flow through successive...

Atrazine sorption by biochar, tire chips, and steel slag as media for blind inlets: A kinetic and isotherm sorption approach

USDA-ARS?s Scientific Manuscript database

Surface inlets are installed in subsurface drainage systems to reduce ponding duration and surface runoff, but can contribute to water quality concerns by allowing water to directly enter buried drains. Blind inlets, consist of perforated pipes covered with gravel and are separated from an overlying...

4R Water Quality Impacts: An Assessment and Synthesis of Forty Years of Drainage Nitrogen Losses.

PubMed

Christianson, L E; Harmel, R D

2015-11-01

The intersection of agricultural drainage and nutrient mobility in the environment has led to multiscale water quality concerns. This work reviewed and quantitatively analyzed nearly 1,000 site-years of subsurface tile drainage nitrogen (N) load data to develop a more comprehensive understanding of the impacts of 4R practices (application of the right source of nutrients, at the right rate and time, and in the right place) within drained landscapes across North America. Using drainage data newly compiled in the "Measured Annual Nutrient loads from AGricultural Environments" (MANAGE) database, relationships were developed across N application rates for nitrate N drainage loads and corn ( L.) yields. The lack of significant differences between N application timing or application method was inconsistent with the current emphasis placed on application timing, in particular, as a water quality improvement strategy ( = 0.934 and 0.916, respectively). Broad-scale analyses such as this can help identify major trends for water quality, but accurate implementation of the 4R approach will require site-specific knowledge to balance agronomic and environmental goals. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

A Pseudo-Vertical Equilibrium Model for Slow Gravity Drainage Dynamics

NASA Astrophysics Data System (ADS)

Becker, Beatrix; Guo, Bo; Bandilla, Karl; Celia, Michael A.; Flemisch, Bernd; Helmig, Rainer

2017-12-01

Vertical equilibrium (VE) models are computationally efficient and have been widely used for modeling fluid migration in the subsurface. However, they rely on the assumption of instant gravity segregation of the two fluid phases which may not be valid especially for systems that have very slow drainage at low wetting phase saturations. In these cases, the time scale for the wetting phase to reach vertical equilibrium can be several orders of magnitude larger than the time scale of interest, rendering conventional VE models unsuitable. Here we present a pseudo-VE model that relaxes the assumption of instant segregation of the two fluid phases by applying a pseudo-residual saturation inside the plume of the injected fluid that declines over time due to slow vertical drainage. This pseudo-VE model is cast in a multiscale framework for vertically integrated models with the vertical drainage solved as a fine-scale problem. Two types of fine-scale models are developed for the vertical drainage, which lead to two pseudo-VE models. Comparisons with a conventional VE model and a full multidimensional model show that the pseudo-VE models have much wider applicability than the conventional VE model while maintaining the computational benefit of the conventional VE model.

Impact of tile drainage on evapotranspiration in South Dakota, USA, based on high spatiotemporal resolution evapotranspiration time series from a multi-satellite data fusion system

USGS Publications Warehouse

Yang, Yun; Anderson, Martha C.; Gao, Feng; Hain, Christopher; Kustas, William P.; Meyers, Tilden P.; Crow, Wade; Finocchiaro, Raymond G.; Otkin, Jason; Sun, Liang; Yang, Yang

2017-01-01

Soil drainage is a widely used agricultural practice in the midwest USA to remove excess soil water to potentially improve the crop yield. Research shows an increasing trend in baseflow and streamflow in the midwest over the last 60 years, which may be related to artificial drainage. Subsurface drainage (i.e., tile) in particular may have strongly contributed to the increase in these flows, because of its extensive use and recent gain in the popularity as a yield-enhancement practice. However, how evapotranspiration (ET) is impacted by tile drainage on a regional level is not well-documented. To explore spatial and temporal ET patterns and their relationship to tile drainage, we applied an energy balance-based multisensor data fusion method to estimate daily 30-m ET over an intensively tile-drained area in South Dakota, USA, from 2005 to 2013. Results suggest that tile drainage slightly decreases the annual cumulative ET, particularly during the early growing season. However, higher mid-season crop water use suppresses the extent of the decrease of the annual cumulative ET that might be anticipated from widespread drainage. The regional water balance analysis during the growing season demonstrates good closure, with the average residual from 2005 to 2012 as low as -3 mm. As an independent check of the simulated ET at the regional scale, the water balance analysis lends additional confidence to the study. The results of this study improve our understanding of the influence of agricultural drainage practices on regional ET, and can affect future decision making regarding tile drainage systems.

SULFATE REDUCTION IN GROUNDWATER: CHARACTERIZATION AND APPLICATIONS FOR REMEDIATION

PubMed Central

Miao, Z.; Brusseau, M. L.; Carroll, K. C.; Carreón-Diazconti, C.; Johnson, B.

2013-01-01

Sulfate is ubiquitous in groundwater, with both natural and anthropogenic sources. Sulfate reduction reactions play a significant role in mediating redox conditions and biogeochemical processes for subsurface systems. They also serve as the basis for innovative in-situ methods for groundwater remediation. An overview of sulfate reduction in subsurface environments is provided, along with a brief discussion of characterization methods and applications for addressing acid mine drainage. We then focus on two innovative, in-situ methods for remediating sulfate-contaminated groundwater, the use of zero-valent iron (ZVI) and the addition of electron-donor substrates. The advantages and limitations associated with the methods are discussed, with examples of prior applications. PMID:21947714

TOUGHREACT: a new code of the TOUGH Family for Non-Isothermal multiphase reactive geochemical transport in variably saturated geologic media

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, Tianfu; Sonnenthal, Eric; Spycher, Nicolas

Coupled modeling of subsurface multiphase fluid and heat flow, solute transport and chemical reactions can be used for the assessment of acid mine drainage remediation, waste disposal sites, hydrothermal convection, contaminant transport, and groundwater quality. We have developed a comprehensive numerical simulator, TOUGHREACT, which considers non-isothermal multi-component chemical transport in both liquid and gas phases. A wide range of subsurface thermo-physical-chemical processes is considered under various thermohydrological and geochemical conditions of pressure, temperature, water saturation, and ionic strength. The code can be applied to one-, two- or three-dimensional porous and fractured media with physical and chemical heterogeneity.

A GIS System for Inferring Subsurface Geology and Material Properties: Proof of Concept

DTIC Science & Technology

2006-09-01

geologic structure. For example, interbedded sedimentary rocks comprise significant proportions of the Appalachian Mountains as well as various mountain ...Pitted surfaces a. Shallow, rounded, non-uniform b. More or less circular Hills and Mountains … Drainage...pear-shaped ap - pendages; talus common at bases of slopes along boundaries; strongly verti- cally jointed; vertical escarpments; co- lumnar jointing

Effect of logging on subsurface pipeflow and erosion: coastal northern California, USA

Treesearch

R. R. Ziemer

1992-01-01

Abstract - Three zero-order swales, each with a contributing drainage area of about 1 ha, were instrumented to measure pipeflows within the Caspar Creek Experimental Watershed in northwestern California, USA. After two winters of data collection, the second-growth forest on two of the swales was clearcut logged. The third swale remained as an uncut control. After...

Influence of structures on drainage patterns in the Tushka region, SW Egypt

NASA Astrophysics Data System (ADS)

Robinson, C. A.; El-Kaliouby, H.; Ghoneim, E.

2017-12-01

Remote sensing (radar, thermal and topographic) and geophysical (Vertical Electrical Sounding and Ground Penetrating Radar) data are used to understand areas with enhanced groundwater potential in deeper aquifer settings between 22°0‧-22°56‧N and 30°21-31°20‧E in the Tushka area of southwest Egypt. The premise is that areas with enhanced groundwater accumulations represent the best locations for agricultural development that is underway in this region and that deeper sources groundwater resources are the most sustainable. New fluvial and structural interpretations emphasize that the desert landscape was produced by fluvial action in the past. The correlation of high drainage and fault densities, coincident with gentle slope, guided sites for geophysical investigation that provides information about the aquifer depth and distribution, and the subsurface distribution of faults. Results confirm the presence of subsurface fault plains and fault zones and potential water aquifers at these locations. Surface environments further demonstrated an abundance of shrubs and cultivatable soils. The new approach therefore is a cost effective and noninvasive technique that can be applied throughout the eastern Sahara to assist in resource management decisions and support the planned agricultural expansion.

Boron contents and isotopic compositions of hog manure, selected fertilizers, and water in Minnesota

USGS Publications Warehouse

Komor, S.C.

1997-01-01

Boron-isotope (δ11B) values may be useful as surrogate tracers of contaminants and indicators of water mixing in agricultural settings. This paper characterizes the B contents and isotopic compositions of hog manure and selected fertilizers, and presents δ11B data for ground and surface water from two agricultural areas. Boron concentrations in dry hog manure averaged 61 mg/kg and in commercial fertilizers ranged from below detection limits in some brands of ammonium nitrate and urea to 382 mg/kg in magnesium sulfate. Values of δ11B of untreated hog manure ranged from 7.2 to 11.2o/oo and of N fertilizers were −2.0 to 0.7o/oo. In 22 groundwater samples from a sand-plain aquifer in east-central Minnesota, B concentrations averaged 0.04 mg/L and δ11B values ranged from 2.3 to 41.5o/oo. Groundwater beneath a hog feedlot and a cultivated field where hog manure was applied had B-isotope compositions consistent with the water containing hog-manure leachate. In a 775-km2 watershed with silty-loam soils in southcentral Minnesota: 18 samples of subsurface drainage from corn (Zea mays L.) and soybean (Glycine max L. Merr.) fields had average B concentrations of 0.06 mg/L and δ11B values of 5.3 to 15.1o/oo; 27 stream samples had average B concentrations of 0.05 mg/L and δ11B values of 1.0 to 19.0o/oo; and eight groundwater samples had average B concentrations of 0.09 mg/L and δ11B values of −0.3 to 23.0o/oo. Values of δ11B and B concentrations, when plotted against one another, define a curved mixing trend that suggests subsurface drainage and stream water contain mixtures of B from shallow and deep groundwater.

Estimation of Tile Drainage Contribution to Streamflow and Nutrient Export Loads

NASA Astrophysics Data System (ADS)

Schilling, K. E.; Arenas Amado, A.; Jones, C. S.; Weber, L. J.

2015-12-01

Subsurface drainage is a very common practice in the agricultural U.S. Midwest. It is typically installed in poorly drained soils in order to enhance crop yields. The presence of tile drains creates a route for agrichemicals to travel and therefore negatively impacts stream water quality. This study estimated through end-member analyses the contributions of tile drainage, groundwater, and surface runoff to streamflow at the watershed scale based on continuously monitored data. Especial attention was devoted to quantifying tile drainage impact on watershed streamflow and nutrient export loads. Data analyzed includes streamflow, rainfall, soil moisture, shallow groundwater levels, in-stream nitrate+nitrite concentrations and specific conductance. Data were collected at a HUC12 watershed located in Northeast Iowa, USA. Approximately 60% of the total watershed area is devoted to agricultural activities and forest and grassland are the other two predominant land uses. Results show that approximately 20% of total annual streamflow comes from tile drainage and during rainfall events tile drainage contribution can go up to 30%. Furthermore, for most of the analyzed rainfall events groundwater responded faster and in a more dramatic fashion than tile drainage. The State of Iowa is currently carrying out a plan to reduce nutrients in Iowa waters and the Gulf of Mexico (Iowa Nutrient Reduction Strategy). The outcome of this investigation has the potential to assist in Best Management Practice (BMP) scenario selection and therefore help the state achieve water quality goals.

Impacts of soil conditioners and water table management on phosphorus loss in tile drainage from a clay loam soil.

PubMed

Zhang, T Q; Tan, C S; Zheng, Z M; Welacky, T W; Reynolds, W D

2015-03-01

Adoption of waste-derived soil conditioners and refined water management can improve soil physical quality and crop productivity of fine-textured soils. However, the impacts of these practices on water quality must be assessed to ensure environmental sustainability. We conducted a study to determine phosphorus (P) loss in tile drainage as affected by two types of soil conditioners (yard waste compost and swine manure compost) and water table management (free drainage and controlled drainage with subirrigation) in a clay loam soil under corn-soybean rotation in a 4-yr period from 1999 to 2003. Tile drainage flows were monitored and sampled on a year-round continuous basis using on-site auto-sampling systems. Water samples were analyzed for dissolved reactive P (DRP), particulate P (PP), and total P (TP). Substantially greater concentrations and losses of DRP, PP, and TP occurred with swine manure compost than with control and yard waste compost regardless of water table management. Compared with free drainage, controlled drainage with subirrigation was an effective way to reduce annual and cumulative losses of DRP, PP, and TP in tile drainage through reductions in flow volume and P concentration with control and yard waste compost but not with swine manure compost. Both DRP and TP concentrations in tile drainage were well above the water quality guideline for P, affirming that subsurface loss of P from fine-textured soils can be one critical source for freshwater eutrophication. Swine manure compost applied as a soil conditioner must be optimized by taking water quality impacts into consideration. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Subsurface geomicrobiology in a Mars terrestrial analogue, Río Tinto (SW, Spain)

NASA Astrophysics Data System (ADS)

Amils, R.; Fernández-Remolar, D.; Gómez, F.; González-Toril, E.; Rodríguez, N.; Prieto-Ballesteros, O.; Sanz, J. L.; Díaz, E.; Stoker, C.

2008-09-01

Since its discovery, only few years ago, subsurface geomicrobiology is a matter of growing interest [1]. From a fundamental point of view, it seeks to determine whether life can be sustained in the absence of radiation. From an astrobiological point of view, it is an interesting model for life in other planetary bodies, e.g., Mars, as well as early life on Earth. Río Tinto is an unusual extreme acidic environment due to its size (around 100 km), constant acidic pH (mean pH 2.3), high concentrations of heavy metals and high level of microbial diversity [2]. Río Tinto rises in the core of the Iberian Pyritic Belt, one of the biggest sulfidic ore deposits in the world [3]. Today it is well stablished that the extreme characteristics of Río Tinto are not due to acid mine drainage from mining activity, as has been suggested in the past. To explore the hypothesis that a continuous underground reactor of chemolithotrophic microorganisms thriving in the rich sulfidic minerals of the Iberian Pyritic Belt is responsible for the extreme conditions found in the system, a drilling project has been developed to detect evidence of subsurface microbial activity and potential resources to support these microbial communities in situ (MARTE project) [4]. Here we report a search for subsurface life in volcanically hosted massive sulfidic deposits from the Iberian Pyritic Belt. Aseptic core samples were obtained within and down-gradient from the massive sulfide deposits and formation water was sampled within the resulting bore holes. Microbial activity was detected in un-contaminated samples by culture-dependent and culture-independent methods. Aerobic iron- and sulfide- oxidizing bacteria, and anaerobic denitrifying thiosulfate-oxidizing bacteria, sulfate reducing bacteria and methanogenic archaea have been identified. Potential energy fluxes detected in the system include oxidation of reduced iron and sulfur, or hydrogen gas coupled to nitrite, sulfate, ferric iron, inorganic carbon or transient oxygen. These results suggest that multiple energy sources are available from sulfide-mineral weathering to support microbial metabolism, even in the absence of atmospheric oxygen. [1] Stevens, T.O and McKinley, J.P. (1995) Scienc,, 270, 450-454. [2] Amis, R. et al. (2007) Planet Space Sci, 55, 370- 381. [3] Fernández-Remolar, D. et al. (2005) Earth Planet Sci Lett, 240, 149-167. [4] Amils, R. et al. (2008) Microbiology of Extreme Soils, 205-223.

Presence and distribution of chlorinated organic compounds in streambed sediments, new jersey

USGS Publications Warehouse

Stackelberg, P.E.

1997-01-01

Concentrations of 18 hydrophobic chlorinated organic compounds in streambed sediments from 100 sites throughout New Jersey were examined to determine (1) which compounds were detected most frequently, (2) whether detection frequencies differed among selected drainage basins, and (3) whether concentrations differed significantly among selected drainage basins. Twelve drainage basins across New Jersey that contain a range of land-use patterns and population densities were selected to represent various types and degrees of development. To ensure an adequate number of samples for statistical comparison among drainage basins, the 12 selected basins were consolidated into seven drainage areas on the basis of similarities in land- use patterns and population densities. Additionally, data for three classes of chlorinated organic compounds in streambed sediments from 255 sites throughout New Jersey were examined to determine whether the presence of these compounds in streambed sediments is related to the type and degree of development within the drainage area of each sampling site. Chlorinated organic compounds detected most frequently within the seven representative drainage areas were DDT, DDE, DDD, chlordane, dieldrin, and PCBs. DDT, DDE, and DDD, which were the most widely distributed organic compounds, were detected in about 60 to 100 percent of the samples from all drainage areas hut one (where the detection rate for these compounds was about 20 to 40 percent). Chlordane and dieldrin were detected in about 80 to 100 percent of samples from highly urbanized and populated drainage areas; detection frequencies for these compounds tended to be smaller in less developed and populated areas. PCBs were detected in about 40 to 85 percent of samples from all drainage areas; detection frequencies were highest in the most heavily developed and populated areas. Analysis of variance on rank-transformed organic compound concentrations normalized to sediment organic carbon content was used to evaluate differences in concentrations among the seven representative drainage areas. Chlordane and PCBs were the chlorinated organic compounds with the most highly elevated concentrations in streambed sediments across the State. Median normalized COncentrations of all six of the most frequently detected chlorinated organic compounds were highest in the most heavily urbanized and populated drainage area and lowest in the less populated, predominantly agricultural or forested areas. Concentrations of DDT and DDE, however, did not differ significantly among most of the drainage areas. Concentrations of DDD, chlordane, dieldrin, and PCBs differed significantly among drainage areas. The highest median normalized concentrations were found in samples from the most heavily urbanized and populated areas, and the lowest were in samples from the least developed, most heavily forested area. Logistic regression was used to examine relations between the presence of hydrophobic chlorinated organic compounds in streambed sediments at specified concentrations and variables that characterize the type and degree of development within the drainage areas of 255 sites across New Jersey. The explanatory variables found most useful for predicting the presence of chlorinated organic compounds in streambed sediments include total population and amounts (in square kilometers) of various land-use categories. Logistic regression equations were developed to identify significant relations between population and amounts of specific land-use categories within drainage areas and the probability of detecting chlorinated organic contaminants in streambed sediments. These relations can be used to assist in the identification of geographic regions of primary concern for contamination of bed sediments by chlorinated organic compounds across the State.

From Río Tinto to Mars: the terrestrial and extraterrestrial ecology of acidophiles.

PubMed

Amils, R; González-Toril, E; Aguilera, A; Rodríguez, N; Fernández-Remolar, D; Gómez, F; García-Moyano, A; Malki, M; Oggerin, M; Sánchez-Andrea, I; Sanz, J L

2011-01-01

The recent geomicrobiological characterization of Río Tinto, Iberian Pyrite Belt (IPB), has proven the importance of the iron cycle, not only in generating the extreme conditions of the habitat (low pH, high concentration of toxic heavy metals) but also in maintaining the high level of microbial diversity, both prokaryotic and eukaryotic, detected in the water column and the sediments. The extreme conditions of the Tinto basin are not the product of industrial contamination but the consequence of the presence of an underground bioreactor that obtains its energy from the massive sulfide minerals of the IPB. To test this hypothesis, a drilling project was carried out to intersect ground waters that interact with the mineral ore in order to provide evidence of subsurface microbial activities and the potential resources to support these activities. The oxidants that drive the system appear to come from the rock matrix, contradicting conventional acid mine drainage models. These resources need only groundwater to launch microbial metabolism. There are several similarities between the vast deposits of sulfates and iron oxides on Mars and the main sulfide-containing iron bioleaching products found in the Tinto. Firstly, the short-lived methane detected both in Mars' atmosphere and in the sediments and subsurface of the IPB and secondly, the abundance of iron, common to both. The physicochemical properties of iron make it a source of energy, a shield against radiation and oxidative stress as well as a natural pH controller. These similarities have led to Río Tinto's status as a Mars terrestrial analogue. Copyright © 2011 Elsevier Inc. All rights reserved.

Subsurface event detection and classification using Wireless Signal Networks.

PubMed

Yoon, Suk-Un; Ghazanfari, Ehsan; Cheng, Liang; Pamukcu, Sibel; Suleiman, Muhannad T

2012-11-05

Subsurface environment sensing and monitoring applications such as detection of water intrusion or a landslide, which could significantly change the physical properties of the host soil, can be accomplished using a novel concept, Wireless Signal Networks (WSiNs). The wireless signal networks take advantage of the variations of radio signal strength on the distributed underground sensor nodes of WSiNs to monitor and characterize the sensed area. To characterize subsurface environments for event detection and classification, this paper provides a detailed list and experimental data of soil properties on how radio propagation is affected by soil properties in subsurface communication environments. Experiments demonstrated that calibrated wireless signal strength variations can be used as indicators to sense changes in the subsurface environment. The concept of WSiNs for the subsurface event detection is evaluated with applications such as detection of water intrusion, relative density change, and relative motion using actual underground sensor nodes. To classify geo-events using the measured signal strength as a main indicator of geo-events, we propose a window-based minimum distance classifier based on Bayesian decision theory. The window-based classifier for wireless signal networks has two steps: event detection and event classification. With the event detection, the window-based classifier classifies geo-events on the event occurring regions that are called a classification window. The proposed window-based classification method is evaluated with a water leakage experiment in which the data has been measured in laboratory experiments. In these experiments, the proposed detection and classification method based on wireless signal network can detect and classify subsurface events.

Subsurface Event Detection and Classification Using Wireless Signal Networks

PubMed Central

Yoon, Suk-Un; Ghazanfari, Ehsan; Cheng, Liang; Pamukcu, Sibel; Suleiman, Muhannad T.

2012-01-01

Subsurface environment sensing and monitoring applications such as detection of water intrusion or a landslide, which could significantly change the physical properties of the host soil, can be accomplished using a novel concept, Wireless Signal Networks (WSiNs). The wireless signal networks take advantage of the variations of radio signal strength on the distributed underground sensor nodes of WSiNs to monitor and characterize the sensed area. To characterize subsurface environments for event detection and classification, this paper provides a detailed list and experimental data of soil properties on how radio propagation is affected by soil properties in subsurface communication environments. Experiments demonstrated that calibrated wireless signal strength variations can be used as indicators to sense changes in the subsurface environment. The concept of WSiNs for the subsurface event detection is evaluated with applications such as detection of water intrusion, relative density change, and relative motion using actual underground sensor nodes. To classify geo-events using the measured signal strength as a main indicator of geo-events, we propose a window-based minimum distance classifier based on Bayesian decision theory. The window-based classifier for wireless signal networks has two steps: event detection and event classification. With the event detection, the window-based classifier classifies geo-events on the event occurring regions that are called a classification window. The proposed window-based classification method is evaluated with a water leakage experiment in which the data has been measured in laboratory experiments. In these experiments, the proposed detection and classification method based on wireless signal network can detect and classify subsurface events. PMID:23202191

Exploration of diffuse and discrete sources of acid mine drainage to a headwater mountain stream in Colorado, USA

USGS Publications Warehouse

Johnston, Allison; Runkel, Robert L.; Navarre-Sitchler, Alexis; Singha, Kamini

2017-01-01

We investigated the impact of acid mine drainage (AMD) contamination from the Minnesota Mine, an inactive gold and silver mine, on Lion Creek, a headwater mountain stream near Empire, Colorado. The objective was to map the sources of AMD contamination, including discrete sources visible at the surface and diffuse inputs that were not readily apparent. This was achieved using geochemical sampling, in-stream and in-seep fluid electrical conductivity (EC) logging, and electrical resistivity imaging (ERI) of the subsurface. The low pH of the AMD-impacted water correlated to high fluid EC values that served as a target for the ERI. From ERI, we identified two likely sources of diffuse contamination entering the stream: (1) the subsurface extent of two seepage faces visible on the surface, and (2) rainfall runoff washing salts deposited on the streambank and in a tailings pile on the east bank of Lion Creek. Additionally, rainfall leaching through the tailings pile is a potential diffuse source of contamination if the subsurface beneath the tailings pile is hydraulically connected with the stream. In-stream fluid EC was lowest when stream discharge was highest in early summer and then increased throughout the summer as stream discharge decreased, indicating that the concentration of dissolved solids in the stream is largely controlled by mixing of groundwater and snowmelt. Total dissolved solids (TDS) load is greatest in early summer and displays a large diel signal. Identification of diffuse sources and variability in TDS load through time should allow for more targeted remediation options.

Nitrate and phosphorus transport through subsurface drains under free and controlled drainage.

PubMed

Saadat, Samaneh; Bowling, Laura; Frankenberger, Jane; Kladivko, Eileen

2018-05-28

Controlled drainage (CD) is a structural conservation practice in which the drainage outlet is managed in order to reduce drain flow volume and nutrient loads to water bodies. The goal of this study was to evaluate the potential of CD to improve water quality for two different seasons and levels of outlet control, using ten years of data collected from an agricultural drained field in eastern Indiana with two sets of paired plots. The Rank Sum test was used to quantify the impact of CD on cumulative annual drain flow and nitrate-N and phosphorus loads. CD plots had a statistically significant (at 5% level) lower annual drain flow (eastern pair: 39%; western pair: 25%) and nitrate load (eastern pair: 43%; western pair: 26%) compared to free draining (FD) plots, while annual soluble reactive phosphorus (SRP) and total phosphorus (TP) loads were not significantly different. An ANCOVA model was used to evaluate the impact of CD on daily drain flow, nitrate-N, SRP and TP concentrations and loads during the two different periods of control. The average percent reduction of daily drain flow was 68% in the eastern pair and 58% in the western pair during controlled drainage at the higher outlet level (winter) and 64% and 58% at the lower outlet level (summer) in the eastern and western pairs, respectively. Nitrate load reduction was similar to drain flow reduction, while the effect of CD on SRP and TP loads was not significant except for the increase in SRP in one pair. These results from a decade-long field monitoring and two different statistical methods enhance our knowledge about water quality impacts of CD system and support this management practice as a reliable system for reducing nitrate loss through subsurface drains, mainly caused by flow reduction. Copyright © 2018 Elsevier Ltd. All rights reserved.

Experimental study on soluble chemical transfer to surface runoff from soil.

PubMed

Tong, Juxiu; Yang, Jinzhong; Hu, Bill X; Sun, Huaiwei

2016-10-01

Prevention of chemical transfer from soil to surface runoff, under condition of irrigation and subsurface drainage, would improve surface water quality. In this paper, a series of laboratory experiments were conducted to assess the effects of various soil and hydraulic factors on chemical transfer from soil to surface runoff. The factors include maximum depth of ponding water on soil surface, initial volumetric water content of soil, depth of soil with low porosity, type or texture of soil and condition of drainage. In the experiments, two soils, sand and loam, mixed with different quantities of soluble KCl were filled in the sandboxes and prepared under different initial saturated conditions. Simulated rainfall induced surface runoff are operated in the soils, and various ponding water depths on soil surface are simulated. Flow rates and KCl concentration of surface runoff are measured during the experiments. The following conclusions are made from the study results: (1) KCl concentration in surface runoff water would decrease with the increase of the maximum depth of ponding water on soil surface; (2) KCl concentration in surface runoff water would increase with the increase of initial volumetric water content in the soil; (3) smaller depth of soil with less porosity or deeper depth of soil with larger porosity leads to less KCl transfer to surface runoff; (4) the soil with finer texture, such as loam, could keep more fertilizer in soil, which will result in more KCl concentration in surface runoff; and (5) good subsurface drainage condition will increase the infiltration and drainage rates during rainfall event and will decrease KCl concentration in surface runoff. Therefore, it is necessary to reuse drained fertile water effectively during rainfall, without polluting groundwater. These study results should be considered in agriculture management to reduce soluble chemical transfer from soil to surface runoff for reducing non-point sources pollution.

Performance of a pilot showcase of different wetland systems in an urban setting in Singapore.

PubMed

Quek, B S; He, Q H; Sim, C H

2015-01-01

The Alexandra Wetlands, part of PUB's Active, Beautiful, Clean Waters (ABC Waters) Programme, showcase a surface flow wetland, an aquatic pond and a sub-surface flow wetland on a 200 m deck built over an urban drainage canal. Water from the canal is pumped to a sedimentation basin, before flowing in parallel to the three wetlands. Water quality monitoring was carried out monthly from April 2011 to December 2012. The order of removal efficiency is sub-surface flow (81.3%) >aquatic pond (58.5%) >surface flow (50.7%) for total suspended solids (TSS); sub-surface (44.9%) >surface flow (31.9%) >aquatic pond (22.0%) for total nitrogen (TN); and surface flow (56.7%) >aquatic pond (39.8%) >sub-surface flow (5.4%) for total phosphorus (TP). All three wetlands achieved the Singapore stormwater treatment objectives (STO) for TP removal, but only the sub-surface flow wetland met the STO for TSS, and none met the STO for TN. Challenges in achieving satisfactory performance include inconsistent feed water quality, undesirable behaviour such as fishing, release of pets and feeding of animals in the wetlands, and canal dredging during part of the monitoring period. As a pilot showcase, the Alexandra Wetlands provide useful lessons for implementing multi-objective wetlands in an urban setting.

Modeling Phosphorus Losses through Surface Runoff and Subsurface Drainage Using ICECREAM.

PubMed

Qi, Hongkai; Qi, Zhiming; Zhang, T Q; Tan, C S; Sadhukhan, Debasis

2018-03-01

Modeling soil phosphorus (P) losses by surface and subsurface flow pathways is essential in developing successful strategies for P pollution control. We used the ICECREAM model to simultaneously simulate P losses in surface and subsurface flow, as well as to assess effectiveness of field practices in reducing P losses. Monitoring data from a mineral-P-fertilized clay loam field in southwestern Ontario, Canada, were used for calibration and validation. After careful adjustment of model parameters, ICECREAM was shown to satisfactorily simulate all major processes of surface and subsurface P losses. When the calibrated model was used to assess tillage and fertilizer management scenarios, results point to a 10% reduction in total P losses by shifting autumn tillage to spring, and a 25.4% reduction in total P losses by injecting fertilizer rather than broadcasting. Although the ICECREAM model was effective in simulating surface and subsurface P losses when thoroughly calibrated, further testing is needed to confirm these results with manure P application. As illustrated here, successful use of simulation models requires careful verification of model routines and comprehensive calibration to ensure that site-specific processes are accurately represented. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Atmospheric nitrogen deposition and habitat alteration in terrestrial and aquatic ecosystems in southern California: implications for threatened and endangered species

Treesearch

Mark Fenn; Mark Poth; Thomas Meixner

2005-01-01

Recent studies in the transverse ranges (including Class I Wilderness areas) of southern California have emphasized the strong linkage between levels of air pollution-related atmospheric nitrogen (N) inputs into montane watersheds and levels of nitrate in surface and subsurface drainage waters (fig. 1). Nitrate concentrations in streamwater in southern California are...

Effects of timber harvesting on the lag time of a Caspar Creek watershed...a study in progress

Treesearch

Karen D. Hardison

1982-01-01

Researchers are not agreed on the effects of logging on lag time. Numerous studies have shown that the use of heavy equipment in logging operations can cause soil compaction. Also, associated roads alter natural drainage patterns by concentrating runoff and interrupting subsurface flow. As a result these researchers say, less infiltration into the soil takes place...

Evaluation of Reactive Mixtures for Treatment of Mine Drainage From a Waste Rock Storage Area in Northern Saskatchewan, Canada

NASA Astrophysics Data System (ADS)

Jeen, S.; Bain, J. G.; Blowes, D. W.

2007-12-01

A column experiment has been conducted to evaluate the performance of three reactive mixtures which may be used in a permeable reactive barrier (PRB) for the treatment of low quality mine drainage water from a waste rock storage area in northern Saskatchewan, Canada. The key element of concern in the drainage water is dissolved Ni, which occurs at approximately 13 mg/L. The water is low pH ~4.3, oxidized, contains high concentrations of dissolved sulfate (4400-4750 mg/L), Al (45 mg/L), Zn (3 mg/L), Co (3 mg/L) and relatively low concentrations of other dissolved heavy metals and iron. Three columns, each containing one of the mixtures, were constructed: column A (peat/lime/limestone/gravel), column B (peat/zero valent iron (ZVI) filings (20%/vol)/limestone/gravel), and column C (peat/ZVI filings (10%/vol)/limestone/gravel). The experimental results have shown that the mixtures promote bacterially-mediated sulfate reduction and metal removal by precipitation of metal sulfides, metal precipitation, and adsorption under relatively high pH conditions (pH of 7 to 8). Reducing conditions (Eh of 0 to -200 mV) have developed in all of the columns, from the highly oxidized influent water (Eh of +500 to +600 mV). Hydrogen sulfide is detected in the effluent water, and dissolved sulfate concentrations decrease by several hundred mg/L. Based on sulfate removal, sulfate reduction occurs more strongly in columns B and C than column A. All of the columns are removing Ni to below the limit of detection (typically < 0.01 mg/L); however, the removal rate in column A is slower than in columns B and C and has decreased over time. Most other metals are removed to low concentrations in all of the columns. The results suggest that while the longevity of mixtures including ZVI will be much longer than mixtures containing only peat, considering economic aspects, the PRB consisting of only peat could also be an alternative option, if breakthrough time can be predicted and replacement of peat can be conducted in a timely manner. This study shows that the use of reactive mixtures that facilitate microbial activities and redox reactions in subsurface could be a valuable means to remove various metal contaminants originated from mine drainage sites.

Surface response of blind thrust shown from high resolution topographic data and updated geochronology at Wheeler Ridge, CA

NASA Astrophysics Data System (ADS)

Kleber, E.; Arrowsmith, R.; DeVecchio, D. E.; Johnstone, S. A.; Rittenour, T. M.

2015-12-01

Wheeler Ridge is an asymmetric east-propagating anticline (10km axis, 330m relief) above a north-vergent blind thrust deforming Quaternary alluvial fan and shallow marine rocks at the northern front of the Transverse Ranges, San Joaquin Valley, CA. This area was a research foci in the 1990's when the soils, u-series soil carbonate dating, and subsurface structure of deformed strata identified from oil wells were used to create a kinematic model of deformation, and estimates of fault slip, uplift, and lateral propagation rates. A recent collection of light detection and ranging (lidar) topographic data and optically stimulated luminescence (OSL) data allow us to complete meter scale topographic analyses of the fluvial networks and hillslopes and correlate geomorphic response to tectonics. We interpret these results using a detailed morphological map and observe drainage network and hillslope process transitions both along and across the fold axis. With lidar topography, we extract common morphometrics (e.g., channel steepness-- ksn, eroded volume, hillslope relief) to illustrate how the landscape is responding to variations in uplift rate along the fold axis and show asymmetry of surface response on the forelimb and backlimb. The forelimb is dominated by large drainages with landslides initiating in the marine units at the core of the fold. Our topographic analysis shows that the stream channel indices values on the forelimb increase along the fold axis, away from the propagation tip. The backlimb drainages are dominantly long and linear with broad ridgelines. Using lidar and fieldwork, we see that uplifted backlimb surfaces preserve the deformed fan surface. The preliminary OSL results from alluvial fan units improve age control of previously defined surfaces, refining our understanding of the deposition and uplift of alluvial fan units on preserved on backlimb.

Estimating drain flow from measured water table depth in layered soils under free and controlled drainage

NASA Astrophysics Data System (ADS)

Saadat, Samaneh; Bowling, Laura; Frankenberger, Jane; Kladivko, Eileen

2018-01-01

Long records of continuous drain flow are important for quantifying annual and seasonal changes in the subsurface drainage flow from drained agricultural land. Missing data due to equipment malfunction and other challenges have limited conclusions that can be made about annual flow and thus nutrient loads from field studies, including assessments of the effect of controlled drainage. Water table depth data may be available during gaps in flow data, providing a basis for filling missing drain flow data; therefore, the overall goal of this study was to examine the potential to estimate drain flow using water table observations. The objectives were to evaluate how the shape of the relationship between drain flow and water table height above drain varies depending on the soil hydraulic conductivity profile, to quantify how well the Hooghoudt equation represented the water table-drain flow relationship in five years of measured data at the Davis Purdue Agricultural Center (DPAC), and to determine the impact of controlled drainage on drain flow using the filled dataset. The shape of the drain flow-water table height relationship was found to depend on the selected hydraulic conductivity profile. Estimated drain flow using the Hooghoudt equation with measured water table height for both free draining and controlled periods compared well to observed flow with Nash-Sutcliffe Efficiency values above 0.7 and 0.8 for calibration and validation periods, respectively. Using this method, together with linear regression for the remaining gaps, a long-term drain flow record for a controlled drainage experiment at the DPAC was used to evaluate the impacts of controlled drainage on drain flow. In the controlled drainage sites, annual flow was 14-49% lower than free drainage.

Leaching of the Neonicotinoids Thiamethoxam and Imidacloprid from Sugar Beet Seed Dressings to Subsurface Tile Drains.

PubMed

Wettstein, Felix E; Kasteel, Roy; Garcia Delgado, Maria F; Hanke, Irene; Huntscha, Sebastian; Balmer, Marianne E; Poiger, Thomas; Bucheli, Thomas D

2016-08-24

Pesticide transport from seed dressings toward subsurface tile drains is still poorly understood. We monitored the neonicotinoid insecticides imidacloprid and thiamethoxam from sugar beet seed dressings in flow-proportional drainage water samples, together with spray applications of bromide and the herbicide S-metolachlor in spring and the fungicides epoxiconazole and kresoxim-methyl in summer. Event-driven, high first concentration maxima up to 2830 and 1290 ng/L for thiamethoxam and imidacloprid, respectively, were followed by an extended period of tailing and suggested preferential flow. Nevertheless, mass recoveries declined in agreement with the degradation and sorption properties collated in the groundwater ubiquity score, following the order bromide (4.9%), thiamethoxam (1.2%), imidacloprid (0.48%), kresoxim-methyl acid (0.17%), S-metolachlor (0.032%), epoxiconazole (0.013%), and kresoxim-methyl (0.003%), and indicated increased leaching from seed dressings compared to spray applications. Measured concentrations and mass recoveries indicate that subsurface tile drains contribute to surface water contamination with neonicotinoids from seed dressings.

Estimation of tile drainage contribution to streamflow and nutrient loads at the watershed scale based on continuously monitored data.

PubMed

Arenas Amado, A; Schilling, K E; Jones, C S; Thomas, N; Weber, L J

2017-09-01

Nitrogen losses from artificially drained watersheds degrade water quality at local and regional scales. In this study, we used an end-member mixing analysis (EMMA) together with high temporal resolution water quality and streamflow data collected in the 122 km 2 Otter Creek watershed located in northeast Iowa. We estimated the contribution of three end-members (groundwater, tile drainage, and quick flow) to streamflow and nitrogen loads and tested several combinations of possible nitrate concentrations for the end-members. Results indicated that subsurface tile drainage is responsible for at least 50% of the watershed nitrogen load between April 15 and November 1, 2015. Tiles delivered up to 80% of the stream N load while providing only 15-43% of the streamflow, whereas quick flows only marginally contributed to N loading. Data collected offer guidance about areas of the watershed that should be targeted for nitrogen export mitigation strategies.

Identifying Hydrologic Flowpaths on Arctic Hillslopes Using Electrical Resistivity and Self Potential

NASA Astrophysics Data System (ADS)

Voytek, E.; Rushlow, C. R.; Godsey, S.; Singha, K.

2015-12-01

Shallow subsurface flow is a dominant process controlling hillslope runoff generation, soil development, and solute reaction and transport. Despite their importance, the location and geometry of flowpaths are difficult to determine. In arctic environments, shallow subsurface flowpaths are limited to a thin zone of seasonal thaw above continuous permafrost, which is traditionally assumed to mimic to surface topography. Here we use a combined approach of electrical resistivity imaging (ERI) and self-potential measurements (SP) to map shallow subsurface flowpaths in and around water tracks, drainage features common to arctic hillslopes. ERI measurements delineate thawed zones in the subsurface that control flowpaths, while SP is sensitive to groundwater flow. We find that areas of low electrical resistivity in the water tracks are deeper than manual thaw depth estimates and variations from surface topography. This finding suggests that traditional techniques significantly underestimate active layer thaw and the extent of the flowpath network on arctic hillslopes. SP measurements identify complex 3-D flowpaths in the thawed zone. Our results lay the groundwork for investigations into the seasonal dynamics, hydrologic connectivity, and climate sensitivity of spatially distributed flowpath networks on arctic hillslopes.

Attributes for NHDPlus Catchments (Version 1.1) in the Conterminous United States: Artificial Drainage (1992) and Irrigation Types (1997)

USGS Publications Warehouse

Wieczorek, Michael; LaMotte, Andrew E.

2010-01-01

This tabular dataset represents the estimated area of artificial drainage for the year 1992 and irrigation types for the year 1997 compiled for every catchment of NHDPlus for the conterminous United States. The source datasets were derived from tabular National Resource Inventory (NRI) datasets created by the National Resources Conservation Service (NRCS, U.S. Department of Agriculture, 1995, 1997). Artificial drainage is defined as subsurface drains and ditches. Irrigation types are defined as gravity and pressure. Subsurface drains are described as conduits, such as corrugated plastic tubing, tile, or pipe, installed beneath the ground surface to collect and/or convey drainage. Surface drainage field ditches are described as graded ditches for collecting excess water. Gravity irrigation source is described as irrigation delivered to the farm and/or field by canals or pipelines open to the atmosphere; and water is distributed by the force of gravity down the field by: (1) A surface irrigation system (border, basin, furrow, corrugation, wild flooding, etc.) or (2) Sub-surface irrigation pipelines or ditches. Pressure irrigation source is described as irrigation delivered to the farm and/or field in pump or elevation-induced pressure pipelines, and water is distributed across the field by: (1) Sprinkle irrigation (center pivot, linear move, traveling gun, side roll, hand move, big gun, or fixed set sprinklers), or (2) Micro irrigation (drip emitters, continuous tube bubblers, micro spray or micro sprinklers). NRI data do not include Federal lands and are thus excluded from this dataset. The tabular data for drainage were spatially apportioned to the National Land Cover Dataset (NLCD, Kerie Hitt, written commun., 2005) and the tabular data for irrigation were spatially apportioned to an enhanced version of the National Land Cover Dataset (NLCDe, Nakagaki and others 2007) The NHDPlus Version 1.1 is an integrated suite of application-ready geospatial datasets that incorporates many of the best features of the National Hydrography Dataset (NHD) and the National Elevation Dataset (NED). The NHDPlus includes a stream network (based on the 1:100,00-scale NHD), improved networking, naming, and value-added attributes (VAAs). NHDPlus also includes elevation-derived catchments (drainage areas) produced using a drainage enforcement technique first widely used in New England, and thus referred to as "the New England Method." This technique involves "burning in" the 1:100,000-scale NHD and when available building "walls" using the National Watershed Boundary Dataset (WBD). The resulting modified digital elevation model (HydroDEM) is used to produce hydrologic derivatives that agree with the NHD and WBD. Over the past two years, an interdisciplinary team from the U.S. Geological Survey (USGS), and the U.S. Environmental Protection Agency (USEPA), and contractors, found that this method produces the best quality NHD catchments using an automated process (USEPA, 2007). The NHDPlus dataset is organized by 18 Production Units that cover the conterminous United States. The NHDPlus version 1.1 data are grouped by the U.S. Geological Survey's Major River Basins (MRBs, Crawford and others, 2006). MRB1, covering the New England and Mid-Atlantic River basins, contains NHDPlus Production Units 1 and 2. MRB2, covering the South Atlantic-Gulf and Tennessee River basins, contains NHDPlus Production Units 3 and 6. MRB3, covering the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy River basins, contains NHDPlus Production Units 4, 5, 7 and 9. MRB4, covering the Missouri River basins, contains NHDPlus Production Units 10-lower and 10-upper. MRB5, covering the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf River basins, contains NHDPlus Production Units 8, 11 and 12. MRB6, covering the Rio Grande, Colorado and Great Basin River basins, contains NHDPlus Production Units 13, 14, 15 and 16. MRB7, covering the Pacific Northwest River basins, contains NHDPlus Production Unit 17. MRB8, covering California River basins, contains NHDPlus Production Unit 18.

Estimating restorable wetland water storage at landscape scales

USGS Publications Warehouse

Jones, Charles Nathan; Evenson, Grey R.; McLaughlin, Daniel L.; Vanderhoof, Melanie; Lang, Megan W.; McCarty, Greg W.; Golden, Heather E.; Lane, Charles R.; Alexander, Laurie C.

2018-01-01

Globally, hydrologic modifications such as ditching and subsurface drainage have significantly reduced wetland water storage capacity (i.e., volume of surface water a wetland can retain) and consequent wetland functions. While wetland area has been well documented across many landscapes and used to guide restoration efforts, few studies have directly quantified the associated wetland storage capacity. Here, we present a novel raster-based approach to quantify both contemporary and potential (i.e., restorable) storage capacities of individual depressional basins across landscapes. We demonstrate the utility of this method by applying it to the Delmarva Peninsula, a region punctuated by both depressional wetlands and drainage ditches. Across the entire peninsula, we estimated that restoration (i.e., plugging ditches) could increase storage capacity by 80%. Focusing on an individual watershed, we found that over 59% of restorable storage capacity occurs within 20 m of the drainage network, and that 93% occurs within 1 m elevation of the drainage network. Our demonstration highlights widespread ditching in this landscape, spatial patterns of both contemporary and potential storage capacities, and clear opportunities for hydrologic restoration. In Delmarva and more broadly, our novel approach can inform targeted landscape-scale conservation and restoration efforts to optimize hydrologically mediated wetland functions.

Estimating restorable wetland water storage at landscape scales.

PubMed

Jones, Charles Nathan; Evenson, Grey R; McLaughlin, Daniel L; Vanderhoof, Melanie K; Lang, Megan W; McCarty, Greg W; Golden, Heather E; Lane, Charles R; Alexander, Laurie C

2018-01-01

Globally, hydrologic modifications such as ditching and subsurface drainage have significantly reduced wetland water storage capacity (i.e., volume of surface water a wetland can retain) and consequent wetland functions. While wetland area has been well documented across many landscapes and used to guide restoration efforts, few studies have directly quantified the associated wetland storage capacity. Here, we present a novel raster-based approach to quantify both contemporary and potential (i.e., restorable) storage capacities of individual depressional basins across landscapes. We demonstrate the utility of this method by applying it to the Delmarva Peninsula, a region punctuated by both depressional wetlands and drainage ditches. Across the entire peninsula, we estimated that restoration (i.e., plugging ditches) could increase storage capacity by 80%. Focusing on an individual watershed, we found that over 59% of restorable storage capacity occurs within 20 m of the drainage network, and that 93% occurs within 1 m elevation of the drainage network. Our demonstration highlights widespread ditching in this landscape, spatial patterns of both contemporary and potential storage capacities, and clear opportunities for hydrologic restoration. In Delmarva and more broadly, our novel approach can inform targeted landscape-scale conservation and restoration efforts to optimize hydrologically mediated wetland functions.

How well will the Surface Water and Ocean Topography (SWOT) mission observe global reservoirs?

NASA Astrophysics Data System (ADS)

Solander, K.; Famiglietti, J. S.; David, C. H.; Reager, J. T., II

2014-12-01

Subsurface drainage is a very common practice in the agricultural U.S. Midwest. It is typically installed in poorly drained soils in order to enhance crop yields. The presence of tile drains creates a route for agrichemicals to travel and therefore negatively impacts stream water quality. This study estimated through end-member analyses the contributions of tile drainage, groundwater, and surface runoff to streamflow at the watershed scale based on continuously monitored data. Especial attention was devoted to quantifying tile drainage impact on watershed streamflow and nutrient export loads. Data analyzed includes streamflow, rainfall, soil moisture, shallow groundwater levels, in-stream nitrate+nitrite concentrations and specific conductance. Data were collected at a HUC12 watershed located in Northeast Iowa, USA. Approximately 60% of the total watershed area is devoted to agricultural activities and forest and grassland are the other two predominant land uses. Results show that approximately 20% of total annual streamflow comes from tile drainage and during rainfall events tile drainage contribution can go up to 30%. Furthermore, for most of the analyzed rainfall events groundwater responded faster and in a more dramatic fashion than tile drainage. The State of Iowa is currently carrying out a plan to reduce nutrients in Iowa waters and the Gulf of Mexico (Iowa Nutrient Reduction Strategy). The outcome of this investigation has the potential to assist in Best Management Practice (BMP) scenario selection and therefore help the state achieve water quality goals.

Characterizing Drainage Multiphase Flow in Heterogeneous Sandstones

NASA Astrophysics Data System (ADS)

Jackson, Samuel J.; Agada, Simeon; Reynolds, Catriona A.; Krevor, Samuel

2018-04-01

In this work, we analyze the characterization of drainage multiphase flow properties on heterogeneous rock cores using a rich experimental data set and mm-m scale numerical simulations. Along with routine multiphase flow properties, 3-D submeter scale capillary pressure heterogeneity is characterized by combining experimental observations and numerical calibration, resulting in a 3-D numerical model of the rock core. The uniqueness and predictive capability of the numerical models are evaluated by accurately predicting the experimentally measured relative permeability of N2—DI water and CO2—brine systems in two distinct sandstone rock cores across multiple fractional flow regimes and total flow rates. The numerical models are used to derive equivalent relative permeabilities, which are upscaled functions incorporating the effects of submeter scale capillary pressure. The functions are obtained across capillary numbers which span four orders of magnitude, representative of the range of flow regimes that occur in subsurface CO2 injection. Removal of experimental boundary artifacts allows the derivation of equivalent functions which are characteristic of the continuous subsurface. We also demonstrate how heterogeneities can be reorientated and restructured to efficiently estimate flow properties in rock orientations differing from the original core sample. This analysis shows how combined experimental and numerical characterization of rock samples can be used to derive equivalent flow properties from heterogeneous rocks.

Changing spatial patterns of evapotranspiration and deep drainage in response to the interactions among impervious surface arrangement, soil characteristics, and weather on a residential parcel.

NASA Astrophysics Data System (ADS)

Voter, C. B.; Steven, L. I.

2015-12-01

The introduction impervious surfaces in urban areas is a key driver of hydrologic change. It is now well understood that the amount of "effective" impervious area directly connected to the storm sewer network is a better indicator of hydrologic behavior than the total amount of impervious area. Most studies in urban hydrology have focused on the relationship between impervious connectivity and stormwater runoff or other surface water flows, with the result that the effect on subsurface flow is not as well understood. In the field, we observe differences in soil moisture availability that are dependent on proximity to impervious features and significant from a root water uptake perspective, which indicates that parcel-scale subsurface and plant water fluxes may also be sensitive to fine-scaled heterogeneity in impervious surface arrangement and connectivity. We use ParFlow with CLM, a watershed model with fully integrated variably-saturated subsurface flow, overland flow, and land-surface processes, to explore the extent to which soil moisture, evapotranspiration, and deep drainage vary under various impervious surface arrangement and soil condition scenarios, as well as under a range of precipitation regimes. We investigate the effect of several impervious surface and soil characteristics, including general lot layout, downspout disconnect, and direction of driveway/sidewalk slope, and soil compaction. We show that that some impervious connectivity schemes transfer more water from impervious areas to pervious ones and promote localized recharge by developing well-defined, fast-moving wetting fronts that are able to penetrate the root zone. Enhanced infiltration is translated more directly to recharge in normal to wet years but partitioned more often to transpiration in dry years, leading to a nonlinear relationship among precipitation, runoff and recharge.

Evaluation of the hooghoudt and kirkham tile drain equations in the soil and water assessment tool to simulate tile flow and nitrate-nitrogen.

PubMed

Moriasi, Daniel N; Gowda, Prasanna H; Arnold, Jeffrey G; Mulla, David J; Ale, Srinivasulu; Steiner, Jean L; Tomer, Mark D

2013-11-01

Subsurface tile drains in agricultural systems of the midwestern United States are a major contributor of nitrate-N (NO-N) loadings to hypoxic conditions in the Gulf of Mexico. Hydrologic and water quality models, such as the Soil and Water Assessment Tool, are widely used to simulate tile drainage systems. The Hooghoudt and Kirkham tile drain equations in the Soil and Water Assessment Tool have not been rigorously tested for predicting tile flow and the corresponding NO-N losses. In this study, long-term (1983-1996) monitoring plot data from southern Minnesota were used to evaluate the SWAT version 2009 revision 531 (hereafter referred to as SWAT) model for accurately estimating subsurface tile drain flows and associated NO-N losses. A retention parameter adjustment factor was incorporated to account for the effects of tile drainage and slope changes on the computation of surface runoff using the curve number method (hereafter referred to as Revised SWAT). The SWAT and Revised SWAT models were calibrated and validated for tile flow and associated NO-N losses. Results indicated that, on average, Revised SWAT predicted monthly tile flow and associated NO-N losses better than SWAT by 48 and 28%, respectively. For the calibration period, the Revised SWAT model simulated tile flow and NO-N losses within 4 and 1% of the observed data, respectively. For the validation period, it simulated tile flow and NO-N losses within 8 and 2%, respectively, of the observed values. Therefore, the Revised SWAT model is expected to provide more accurate simulation of the effectiveness of tile drainage and NO-N management practices. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Filling the gap: using non-invasive geophysical methods to monitor the processes leading to enhanced carbon turnover induced by periodic water table fluctuations

NASA Astrophysics Data System (ADS)

Mellage, A.; Pronk, G.; Atekwana, E. A.; Furman, A.; Rezanezhad, F.; Van Cappellen, P.

2017-12-01

Subsurface transition environments such as the capillary fringe are characterized by steep gradients in redox conditions. Spatial and temporal variations in electron acceptor and donor availability - driven by hydrological changes - may enhance carbon turnover, in some cases resulting in pulses of CO2-respiration. Filling the mechanistic knowledge gap between the hydrological driver and its biogeochemical effects hinges on our ability to monitor microbial activity and key geochemical markers at a high spatial and temporal resolution. However, direct access to subsurface biogeochemical processes is logistically difficult, invasive and usually expensive. In-line, non-invasive geophysical techniques - Spectral Induced Polarization (SIP) and Electrodic Potential (EP), specifically - offer a comparatively inexpensive alternative and can provide data with high spatial and temporal resolution. The challenge lies in linking electrical responses to specific changes in biogeochemical processes. We conducted SIP and EP measurements on a soil column experiment where an artificial soil mixture was subjected to monthly drainage and imbibition cycles. SIP responses showed a clear dependence on redox zonation and microbial abundance. Temporally variable responses exhibited no direct moisture dependence suggesting that the measured responses recorded changes in microbial activity and coincided with the depth interval over which enhanced carbon turnover was observed. EP measurements detected the onset of sulfate mineralization and mapped its depth zonation. SIP and EP signals thus detected enhanced microbial activity within the water table fluctuation zone as well as the timing of the development of specific reactive processes. These findings can be used to relate measured electrical signals to specific reaction pathways and help inform reactive transport models, increasing their predictive capabilities.

Optical method and apparatus for detection of surface and near-subsurface defects in dense ceramics

DOEpatents

Ellingson, William A.; Brada, Mark P.

1995-01-01

A laser is used in a non-destructive manner to detect surface and near-subsurface defects in dense ceramics and particularly in ceramic bodies with complex shapes such as ceramic bearings, turbine blades, races, and the like. The laser's wavelength is selected based upon the composition of the ceramic sample and the laser can be directed on the sample while the sample is static or in dynamic rotate or translate motion. Light is scattered off surface and subsurface defects using a preselected polarization. The change in polarization angle is used to select the depth and characteristics of surface/subsurface defects. The scattered light is detected by an optical train consisting of a charge coupled device (CCD), or vidicon, television camera which, in turn, is coupled to a video monitor and a computer for digitizing the image. An analyzing polarizer in the optical train allows scattered light at a given polarization angle to be observed for enhancing sensitivity to either surface or near-subsurface defects. Application of digital image processing allows subtraction of digitized images in near real-time providing enhanced sensitivity to subsurface defects. Storing known "feature masks" of identified defects in the computer and comparing the detected scatter pattern (Fourier images) with the stored feature masks allows for automatic classification of detected defects.

High resolution subsurface imaging using resonance-enhanced detection in 2nd-harmonic KPFM.

PubMed

Cadena, Maria Jose; Reifenberger, Ronald G; Raman, Arvind

2018-06-28

Second harmonic Kelvin probe force microscopy is a robust mechanism for subsurface imaging at the nanoscale. Here we exploit resonance-enhanced detection as a way to boost the subsurface contrast with higher force sensitivity using lower bias voltages, in comparison to the traditional off-resonance case. In this mode, the second harmonic signal of the electrostatic force is acquired at one of the eigenmode frequencies of the microcantilever. As a result, high-resolution subsurface images are obtained in a variety of nanocomposites. To further understand the subsurface imaging detection upon electrostatic forces, we use a finite element model that approximates the geometry of the probe and sample. This allows the investigation of the contrast mechanism, the depth sensitivity and lateral resolution depending on tip-sample properties. © 2018 IOP Publishing Ltd.

Object detection with a multistatic array using singular value decomposition

DOEpatents

Hallquist, Aaron T.; Chambers, David H.

2014-07-01

A method and system for detecting the presence of subsurface objects within a medium is provided. In some embodiments, the detection system operates in a multistatic mode to collect radar return signals generated by an array of transceiver antenna pairs that is positioned across a surface and that travels down the surface. The detection system converts the return signals from a time domain to a frequency domain, resulting in frequency return signals. The detection system then performs a singular value decomposition for each frequency to identify singular values for each frequency. The detection system then detects the presence of a subsurface object based on a comparison of the identified singular values to expected singular values when no subsurface object is present.

Buried object detection in GPR images

DOEpatents

Paglieroni, David W; Chambers, David H; Bond, Steven W; Beer, W. Reginald

2014-04-29

A method and system for detecting the presence of subsurface objects within a medium is provided. In some embodiments, the imaging and detection system operates in a multistatic mode to collect radar return signals generated by an array of transceiver antenna pairs that is positioned across the surface and that travels down the surface. The imaging and detection system pre-processes the return signal to suppress certain undesirable effects. The imaging and detection system then generates synthetic aperture radar images from real aperture radar images generated from the pre-processed return signal. The imaging and detection system then post-processes the synthetic aperture radar images to improve detection of subsurface objects. The imaging and detection system identifies peaks in the energy levels of the post-processed image frame, which indicates the presence of a subsurface object.

Volume reduction outweighs biogeochemical processes in controlling phosphorus treatment in aged detention systems

NASA Astrophysics Data System (ADS)

Shukla, Asmita; Shukla, Sanjay; Annable, Michael D.; Hodges, Alan W.

2017-08-01

Stormwater detention areas (SDAs) play an important role in treating end-of-the-farm runoff in phosphorous (P) limited agroecosystems. Phosphorus transport from the SDAs, including those through subsurface pathways, are not well understood. The prevailing understanding of these systems assumes that biogeochemical processes play the primary treatment role and that subsurface losses can be neglected. Water and P fluxes from a SDA located in a row-crop farm were measured for two years (2009-2011) to assess the SDA's role in reducing downstream P loads. The SDA treated 55% (497 kg) and 95% (205 kg) of the incoming load during Year 1 (Y1, 09-10) and Year 2 (Y2, 10-11), respectively. These treatment efficiencies were similar to surface water volumetric retention (49% in Y1 and 84% in Y2) and varied primarily with rainfall. Similar water volume and P retentions indicate that volume retention is the main process controlling P loads. A limited role of biogeochemical processes was supported by low to no remaining soil P adsorption capacity due to long-term drainage P input. The fact that outflow P concentrations (Y1 = 368.3 μg L- 1, Y2 = 230.4 μg L- 1) could be approximated by using a simple mixing of rainfall and drainage P input further confirmed the near inert biogeochemical processes. Subsurface P losses through groundwater were 304 kg (27% of inflow P) indicating that they are an important source for downstream P. Including subsurface P losses reduces the treatment efficiency to 35% (from 61%). The aboveground biomass in the SDA contained 42% (240 kg) of the average incoming P load suggesting that biomass harvesting could be a cost-effective alternative for reviving the role of biogeochemical processes to enhance P treatment in aged, P-saturated SDAs. The 20-year present economic value of P removal through harvesting was estimated to be 341,000, which if covered through a cost share or a payment for P treatment services program could be a positive outcome for both agriculture and public interests.

Volume reduction outweighs biogeochemical processes in controlling phosphorus treatment in aged detention systems.

PubMed

Shukla, Asmita; Shukla, Sanjay; Annable, Michael D; Hodges, Alan W

2017-08-01

Stormwater detention areas (SDAs) play an important role in treating end-of-the-farm runoff in phosphorous (P) limited agroecosystems. Phosphorus transport from the SDAs, including those through subsurface pathways, are not well understood. The prevailing understanding of these systems assumes that biogeochemical processes play the primary treatment role and that subsurface losses can be neglected. Water and P fluxes from a SDA located in a row-crop farm were measured for two years (2009-2011) to assess the SDA's role in reducing downstream P loads. The SDA treated 55% (497kg) and 95% (205kg) of the incoming load during Year 1 (Y1, 09-10) and Year 2 (Y2, 10-11), respectively. These treatment efficiencies were similar to surface water volumetric retention (49% in Y1 and 84% in Y2) and varied primarily with rainfall. Similar water volume and P retentions indicate that volume retention is the main process controlling P loads. A limited role of biogeochemical processes was supported by low to no remaining soil P adsorption capacity due to long-term drainage P input. The fact that outflow P concentrations (Y1=368.3μg L -1 , Y2=230.4μg L -1 ) could be approximated by using a simple mixing of rainfall and drainage P input further confirmed the near inert biogeochemical processes. Subsurface P losses through groundwater were 304kg (27% of inflow P) indicating that they are an important source for downstream P. Including subsurface P losses reduces the treatment efficiency to 35% (from 61%). The aboveground biomass in the SDA contained 42% (240kg) of the average incoming P load suggesting that biomass harvesting could be a cost-effective alternative for reviving the role of biogeochemical processes to enhance P treatment in aged, P-saturated SDAs. The 20-year present economic value of P removal through harvesting was estimated to be $341,000, which if covered through a cost share or a payment for P treatment services program could be a positive outcome for both agriculture and public interests. Copyright © 2017. Published by Elsevier B.V.

Earth analysis methods, subsurface feature detection methods, earth analysis devices, and articles of manufacture

DOEpatents

West, Phillip B [Idaho Falls, ID; Novascone, Stephen R [Idaho Falls, ID; Wright, Jerry P [Idaho Falls, ID

2012-05-29

Earth analysis methods, subsurface feature detection methods, earth analysis devices, and articles of manufacture are described. According to one embodiment, an earth analysis method includes engaging a device with the earth, analyzing the earth in a single substantially lineal direction using the device during the engaging, and providing information regarding a subsurface feature of the earth using the analysis.

Earth analysis methods, subsurface feature detection methods, earth analysis devices, and articles of manufacture

DOEpatents

West, Phillip B [Idaho Falls, ID; Novascone, Stephen R [Idaho Falls, ID; Wright, Jerry P [Idaho Falls, ID

2011-09-27

Earth analysis methods, subsurface feature detection methods, earth analysis devices, and articles of manufacture are described. According to one embodiment, an earth analysis method includes engaging a device with the earth, analyzing the earth in a single substantially lineal direction using the device during the engaging, and providing information regarding a subsurface feature of the earth using the analysis.

Optical method and apparatus for detection of surface and near-subsurface defects in dense ceramics

DOEpatents

Ellingson, W.A.; Brada, M.P.

1995-06-20

A laser is used in a non-destructive manner to detect surface and near-subsurface defects in dense ceramics and particularly in ceramic bodies with complex shapes such as ceramic bearings, turbine blades, races, and the like. The laser`s wavelength is selected based upon the composition of the ceramic sample and the laser can be directed on the sample while the sample is static or in dynamic rotate or translate motion. Light is scattered off surface and subsurface defects using a preselected polarization. The change in polarization angle is used to select the depth and characteristics of surface/subsurface defects. The scattered light is detected by an optical train consisting of a charge coupled device (CCD), or vidicon, television camera which, in turn, is coupled to a video monitor and a computer for digitizing the image. An analyzing polarizer in the optical train allows scattered light at a given polarization angle to be observed for enhancing sensitivity to either surface or near-subsurface defects. Application of digital image processing allows subtraction of digitized images in near real-time providing enhanced sensitivity to subsurface defects. Storing known ``feature masks`` of identified defects in the computer and comparing the detected scatter pattern (Fourier images) with the stored feature masks allows for automatic classification of detected defects. 29 figs.

On the theory of drainage area for regular and non-regular points.

PubMed

Bonetti, S; Bragg, A D; Porporato, A

2018-03-01

The drainage area is an important, non-local property of a landscape, which controls surface and subsurface hydrological fluxes. Its role in numerous ecohydrological and geomorphological applications has given rise to several numerical methods for its computation. However, its theoretical analysis has lagged behind. Only recently, an analytical definition for the specific catchment area was proposed (Gallant & Hutchinson. 2011 Water Resour. Res. 47 , W05535. (doi:10.1029/2009WR008540)), with the derivation of a differential equation whose validity is limited to regular points of the watershed. Here, we show that such a differential equation can be derived from a continuity equation (Chen et al. 2014 Geomorphology 219 , 68-86. (doi:10.1016/j.geomorph.2014.04.037)) and extend the theory to critical and singular points both by applying Gauss's theorem and by means of a dynamical systems approach to define basins of attraction of local surface minima. Simple analytical examples as well as applications to more complex topographic surfaces are examined. The theoretical description of topographic features and properties, such as the drainage area, channel lines and watershed divides, can be broadly adopted to develop and test the numerical algorithms currently used in digital terrain analysis for the computation of the drainage area, as well as for the theoretical analysis of landscape evolution and stability.

On the theory of drainage area for regular and non-regular points

NASA Astrophysics Data System (ADS)

Bonetti, S.; Bragg, A. D.; Porporato, A.

2018-03-01

The drainage area is an important, non-local property of a landscape, which controls surface and subsurface hydrological fluxes. Its role in numerous ecohydrological and geomorphological applications has given rise to several numerical methods for its computation. However, its theoretical analysis has lagged behind. Only recently, an analytical definition for the specific catchment area was proposed (Gallant & Hutchinson. 2011 Water Resour. Res. 47, W05535. (doi:10.1029/2009WR008540)), with the derivation of a differential equation whose validity is limited to regular points of the watershed. Here, we show that such a differential equation can be derived from a continuity equation (Chen et al. 2014 Geomorphology 219, 68-86. (doi:10.1016/j.geomorph.2014.04.037)) and extend the theory to critical and singular points both by applying Gauss's theorem and by means of a dynamical systems approach to define basins of attraction of local surface minima. Simple analytical examples as well as applications to more complex topographic surfaces are examined. The theoretical description of topographic features and properties, such as the drainage area, channel lines and watershed divides, can be broadly adopted to develop and test the numerical algorithms currently used in digital terrain analysis for the computation of the drainage area, as well as for the theoretical analysis of landscape evolution and stability.

Raman spectroscopy method for subsurface detection of food powders through plastic layers

NASA Astrophysics Data System (ADS)

Dhakal, Sagar; Chao, Kuanglin; Qin, Jianwei; Schmidt, Walter F.; Kim, Moon S.; Chan, Diane E.; Bae, Abigail

2017-05-01

Proper chemical analyses of materials in sealed containers are important for quality control purpose. Although it is feasible to detect chemicals at top surface layer, it is relatively challenging to detect objects beneath obscuring surface. This study used spatially offset Raman spectroscopy (SORS) method to detect urea, ibuprofen and acetaminophen powders contained within one or more (up to eight) layers of gelatin capsules to demonstrate subsurface chemical detection and identification. A 785 nm point-scan Raman spectroscopy system was used to acquire spatially offset Raman spectra for an offset range of 0 to 10 mm from the surfaces of 24 encapsulated samples, using a step size of 0.1 mm to obtain 101 spectral measurements per sample. With increasing offset distance, the fraction of information from the deeper subsurface material increased compared to that from the top surface material. The series of measurements was analyzed to differentiate and identify the top surface and subsurface materials. Containing mixed contributions from the powder and capsule, the SORS of each sample was decomposed using self modeling mixture analysis (SMA) to obtain pure component spectra of each component and corresponding components were identified using spectral information divergence values. Results show that SORS technique together with SMA method has a potential for non-invasive detection of chemicals at deep subsurface layer.

Spot restoration for GPR image post-processing

DOEpatents

Paglieroni, David W; Beer, N. Reginald

2014-05-20

A method and system for detecting the presence of subsurface objects within a medium is provided. In some embodiments, the imaging and detection system operates in a multistatic mode to collect radar return signals generated by an array of transceiver antenna pairs that is positioned across the surface and that travels down the surface. The imaging and detection system pre-processes the return signal to suppress certain undesirable effects. The imaging and detection system then generates synthetic aperture radar images from real aperture radar images generated from the pre-processed return signal. The imaging and detection system then post-processes the synthetic aperture radar images to improve detection of subsurface objects. The imaging and detection system identifies peaks in the energy levels of the post-processed image frame, which indicates the presence of a subsurface object.

Detection and analysis of morphotectonic features utilizing satellite remote sensing and GIS: An example in SW Jordan

NASA Astrophysics Data System (ADS)

Radaideh, Omar M. A.; Grasemann, Bernhard; Melichar, Rostislav; Mosar, Jon

2016-12-01

This study investigates the dominant orientations of morphological features and the relationship between these trends and the spatial orientation of tectonic structures in SW Jordan. Landsat 8 and hill-shaded images, constructed from 30 m-resolution ASTER-GDEM data, were used for automatically extracting and mapping geological lineaments. The ASTER-GDEM was further utilized to automatically identify and extract drainage network. Morphological features were analyzed by means of azimuth frequency and length density distributions. Tectonic controls on the land surface were evaluated using longitudinal profiles of many westerly flowing streams. The profiles were taken directly across the northerly trending faults within a strong topographic transition between the low-gradient uplands and the deeply incised mountain front on the east side of the Dead Sea Fault Zone. Streams of the area are widely divergent, and show numerous anomalies along their profiles when they transect faults and lineaments. Five types of drainage patterns were identified: dendritic, parallel, rectangular, trellis, and modified dendritic/trellis. Interpretation and analysis of the lineaments indicate the presence of four main lineament populations that trend E-W, N-S, NE-SW, and NW-SE. Azimuthal distribution analysis of both the measured structures and drainage channels shows similar trends, except for very few differences in the prevailing directions. The similarity in orientation of lineaments, drainage system, and subsurface structural trends highlights the degree of control exerted by underlying structure on the surface geomorphological features. Faults and lineaments serve as a preferential conduit for surface running waters. The extracted lineaments were divided into five populations based on the main age of host rocks outcropping in the study area to obtain information about the temporal evolution of the lineament trends through geologic time. A general consistency in lineament trends over the different lithological units was observed, most probably because repeated reactivation of tectonism along preexisting deep structural discontinuities which are apparently crustal weakness zones. The reactivation along such inherited discontinuities under the present-day stress field is the most probable explanation of the complicated pattern and style of present-day landscape features in SW Jordan.

Real-time system for imaging and object detection with a multistatic GPR array

DOEpatents

Paglieroni, David W; Beer, N Reginald; Bond, Steven W; Top, Philip L; Chambers, David H; Mast, Jeffrey E; Donetti, John G; Mason, Blake C; Jones, Steven M

2014-10-07

A method and system for detecting the presence of subsurface objects within a medium is provided. In some embodiments, the imaging and detection system operates in a multistatic mode to collect radar return signals generated by an array of transceiver antenna pairs that is positioned across the surface and that travels down the surface. The imaging and detection system pre-processes the return signal to suppress certain undesirable effects. The imaging and detection system then generates synthetic aperture radar images from real aperture radar images generated from the pre-processed return signal. The imaging and detection system then post-processes the synthetic aperture radar images to improve detection of subsurface objects. The imaging and detection system identifies peaks in the energy levels of the post-processed image frame, which indicates the presence of a subsurface object.

Characteristics of ejecta and alluvial deposits at Meteor Crater, Arizona and Odessa Craters, Texas: Results from ground penetrating radar

NASA Technical Reports Server (NTRS)

Grant, J. A.; Schultz, P. H.

1991-01-01

Previous ground penetrating radar (GRP) studies around 50,000 year old Meteor Crater revealed the potential for rapid, inexpensive, and non-destructive sub-surface investigations for deep reflectors (generally greater than 10 m). New GRP results are summarized focusing the shallow sub-surfaces (1-2 m) around Meteor Crater and the main crater at Odessa. The following subject areas are covered: (1) the thickness, distribution, and nature of the contact between surrounding alluvial deposits and distal ejecta; and (2) stratigraphic relationships between both the ejecta and alluvium derived from both pre and post crater drainages. These results support previous conclusions indicating limited vertical lowering (less than 1 m) of the distal ejecta at Meteor Crater and allow initial assessment of the gradational state if the Odessa craters.

Radar signal pre-processing to suppress surface bounce and multipath

DOEpatents

Paglieroni, David W; Mast, Jeffrey E; Beer, N. Reginald

2013-12-31

A method and system for detecting the presence of subsurface objects within a medium is provided. In some embodiments, the imaging and detection system operates in a multistatic mode to collect radar return signals generated by an array of transceiver antenna pairs that is positioned across the surface and that travels down the surface. The imaging and detection system pre-processes that return signal to suppress certain undesirable effects. The imaging and detection system then generates synthetic aperture radar images from real aperture radar images generated from the pre-processed return signal. The imaging and detection system then post-processes the synthetic aperture radar images to improve detection of subsurface objects. The imaging and detection system identifies peaks in the energy levels of the post-processed image frame, which indicates the presence of a subsurface object.

Spatially assisted down-track median filter for GPR image post-processing

DOEpatents

Paglieroni, David W; Beer, N Reginald

2014-10-07

A method and system for detecting the presence of subsurface objects within a medium is provided. In some embodiments, the imaging and detection system operates in a multistatic mode to collect radar return signals generated by an array of transceiver antenna pairs that is positioned across the surface and that travels down the surface. The imaging and detection system pre-processes the return signal to suppress certain undesirable effects. The imaging and detection system then generates synthetic aperture radar images from real aperture radar images generated from the pre-processed return signal. The imaging and detection system then post-processes the synthetic aperture radar images to improve detection of subsurface objects. The imaging and detection system identifies peaks in the energy levels of the post-processed image frame, which indicates the presence of a subsurface object.

Spatially adaptive migration tomography for multistatic GPR imaging

DOEpatents

Paglieroni, David W; Beer, N. Reginald

2013-08-13

A method and system for detecting the presence of subsurface objects within a medium is provided. In some embodiments, the imaging and detection system operates in a multistatic mode to collect radar return signals generated by an array of transceiver antenna pairs that is positioned across the surface and that travels down the surface. The imaging and detection system pre-processes the return signal to suppress certain undesirable effects. The imaging and detection system then generates synthetic aperture radar images from real aperture radar images generated from the pre-processed return signal. The imaging and detection system then post-processes the synthetic aperture radar images to improve detection of subsurface objects. The imaging and detection system identifies peaks in the energy levels of the post-processed image frame, which indicates the presence of a subsurface object.

Synthetic aperture integration (SAI) algorithm for SAR imaging

DOEpatents

Chambers, David H; Mast, Jeffrey E; Paglieroni, David W; Beer, N. Reginald

2013-07-09

A method and system for detecting the presence of subsurface objects within a medium is provided. In some embodiments, the imaging and detection system operates in a multistatic mode to collect radar return signals generated by an array of transceiver antenna pairs that is positioned across the surface and that travels down the surface. The imaging and detection system pre-processes the return signal to suppress certain undesirable effects. The imaging and detection system then generates synthetic aperture radar images from real aperture radar images generated from the pre-processed return signal. The imaging and detection system then post-processes the synthetic aperture radar images to improve detection of subsurface objects. The imaging and detection system identifies peaks in the energy levels of the post-processed image frame, which indicates the presence of a subsurface object.

Zero source insertion technique to account for undersampling in GPR imaging

DOEpatents

Chambers, David H; Mast, Jeffrey E; Paglieroni, David W

2014-02-25

A method and system for detecting the presence of subsurface objects within a medium is provided. In some embodiments, the imaging and detection system operates in a multistatic mode to collect radar return signals generated by an array of transceiver antenna pairs that is positioned across the surface and that travels down the surface. The imaging and detection system pre-processes the return signal to suppress certain undesirable effects. The imaging and detection system then generates synthetic aperture radar images from real aperture radar images generated from the pre-processed return signal. The imaging and detection system then post-processes the synthetic aperture radar images to improve detection of subsurface objects. The imaging and detection system identifies peaks in the energy levels of the post-processed image frame, which indicates the presence of a subsurface object.

Widespread surface meltwater drainage in Antarctica

NASA Astrophysics Data System (ADS)

Kingslake, J.; Ely, J.; Das, I.; Bell, R. E.

2016-12-01

Surface meltwater is thought to cause ice-shelf disintegration, which accelerates the contribution of ice sheets to sea-level rise. Antarctic surface melting is predicted to increase and trigger further ice-shelf disintegration during this century. These climate-change impacts could be modulated by an active hydrological network analogous to the one in operation in Greenland. Despite some observations of Antarctic surface and sub-surface hydrological systems, large-scale active surface drainage in Antarctica has rarely been studied. We use satellite imagery and aerial photography to reveal widespread active hydrology on the surface of the Antarctic Ice Sheet as far south as 85o and as high as 1800 m a.s.l., often near mountain peaks that protrude through the ice (nunataks) and relatively low-albedo `blue-ice areas'. Despite predominantly sub-zero regional air temperatures, as simulated by a regional climate model, Antarctic active drainage has persisted for decades, transporting water through surface streams and feeding vast melt ponds up to 80 km long. Drainage networks (the largest are over 100 km in length) form on flat ice shelves, steep outlet glaciers and ice-sheet flanks across the West and East Antarctica Ice Sheets. Motivated by the proximity of many drainage systems to low-albedo rock and blue-ice areas, we hypothesize a positive feedback between exposed-rock extent, BIA formation, melting and ice-sheet thinning. This feedback relies on drainage moving water long distances from areas near exposed rock, across the grounding line onto and across ice shelves - a process we observe, but had previously thought to be unlikely in Antarctica. This work highlights previously-overlooked processes, not captured by current regional-scale models, which may accelerate the retreat of the Antarctic Ice Sheet.

Surface runoff and tile drainage transport of phosphorus in the midwestern United States.

PubMed

Smith, Douglas R; King, Kevin W; Johnson, Laura; Francesconi, Wendy; Richards, Pete; Baker, Dave; Sharpley, Andrew N

2015-03-01

The midwestern United States offers some of the most productive agricultural soils in the world. Given the cool humid climate, much of the region would not be able to support agriculture without subsurface (tile) drainage because high water tables may damage crops and prevent machinery usage in fields at critical times. Although drainage is designed to remove excess soil water as quickly as possible, it can also rapidly transport agrochemicals, including phosphorus (P). This paper illustrates the potential importance of tile drainage for P transport throughout the midwestern United States. Surface runoff and tile drainage from fields in the St. Joseph River Watershed in northeastern Indiana have been monitored since 2008. Although the traditional concept of tile drainage has been that it slowly removes soil matrix flow, peak tile discharge occurred at the same time as peak surface runoff, which demonstrates a strong surface connection through macropore flow. On our research fields, 49% of soluble P and 48% of total P losses occurred via tile discharge. Edge-of-field soluble P and total P areal loads often exceeded watershed-scale areal loadings from the Maumee River, the primary source of nutrients to the western basin of Lake Erie, where algal blooms have been a pervasive problem for the last 10 yr. As farmers, researchers, and policymakers search for treatments to reduce P loading to surface waters, the present work demonstrates that treating only surface runoff may not be sufficient to reach the goal of 41% reduction in P loading for the Lake Erie Basin. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Hursh CR and Brater EF (1941) separating storm-hydrographs from small drainage-areas into surface- and subsurface-flow. Transactions, American Geophysical Union 22:863-871

Treesearch

T.P. Burt; W.T. Swank

2010-01-01

The Coweeta Hydrologic Laboratory was established in 1934 (originally known as the ‘Coweeta Experimental Forest’). A symposium to celebrate its 75th anniversary in 2009 was an opportunity to acknowledge that some of the world’s most important long-term research in forest hydrology and ecology has been conducted there (Swank and Vose, 2009).

Remote sensing of the hydrologic history of the eastern Sahara

NASA Astrophysics Data System (ADS)

Farr, T. G.; Blom, R. G.; Paillou, P.

2010-12-01

The eastern Sahara Desert has never been thoroughly mapped in terms of the landforms and subsurface signs of past climates conducive to human occupation. As part of ongoing work and through a new proposal to NASA, we are generating new maps of the paleohydrology, topography, geomorphology, and surficial deposits of the area and developing GIS-based models which use the data to pinpoint past resources and travel pathways. The maps we are generating will constitute a unique resource for exploration for water and archeological sites in the Gilf Kebir and other regions of NE Africa. That the Sahara was favorable for human habitation at times has long been known. With the remarkable paleo-landscape revealed by the L-band (25 cm) Shuttle Imaging Radar-A in 1981, it became clear that ancient humans concentrated along integrated drainage systems dubbed “radar rivers” by McCauley and colleagues. However SIR-A and subsequent long-wavelength radar coverage was limited and regional understanding of the drainage network has remained elusive. We are mapping the area with three sensors optimized for mapping and characterizing arid regions: The Japanese PALSAR L-band imaging radar, NASA’s SRTM, and ASTER. Together these sensors provide full coverage of the area allowing characterization and mapping of surface and subsurface landforms formed and modified by former wetter climates. In particular and following the work of Ghoneim, Robinson, El Baz and others, we are mapping the regional drainage network revealed by the radar images and applying modern analysis tools to the drainage basins and channels. These include drainage density, channel gradient vs. distance, and longitudinal and cross-channel topographic profiles. We use these quantities to estimate a stream’s past approach to equilibrium and this to infer balances between climate, tectonic uplift, and other changes in base level. Discovery over the last few years of large paleolakes (e.g. Mega Lake Chad, North Darfur Lake, etc.) also provide a constraint on Pleistocene rainfall in the area. Archaeologists have never had a synoptic view of the region around Gilf Kebir. In addition, the national governments of the region need a detailed map of landforms and resources for conservation efforts. The data and maps produced by this study will be unique and will be used for many years as a base for further studies of the archaeology of the region as well as other applications in hydrology, ecology, geomorphology, and tourism. Part of this work was done under contract with NASA.

Subsurface Contamination Control

DOE Office of Scientific and Technical Information (OSTI.GOV)

Y. Yuan

There are two objectives of this report, ''Subsurface Contamination Control''. The first is to provide a technical basis for recommending limiting radioactive contamination levels (LRCL) on the external surfaces of waste packages (WP) for acceptance into the subsurface repository. The second is to provide an evaluation of the magnitude of potential releases from a defective WP and the detectability of the released contents. The technical basis for deriving LRCL has been established in ''Retrieval Equipment and Strategy for Wp on Pallet'' (CRWMS M and O 2000g, 6.3.1). This report updates the derivation by incorporating the latest design information of themore » subsurface repository for site recommendation. The derived LRCL on the external surface of WPs, therefore, supercede that described in CRWMS M and O 2000g. The derived LRCL represent the average concentrations of contamination on the external surfaces of each WP that must not be exceeded before the WP is to be transported to the subsurface facility for emplacement. The evaluation of potential releases is necessary to control the potential contamination of the subsurface repository and to detect prematurely failed WPs. The detection of failed WPs is required in order to provide reasonable assurance that the integrity of each WP is intact prior to MGR closure. An emplaced WP may become breached due to manufacturing defects or improper weld combined with failure to detect the defect, by corrosion, or by mechanical penetration due to accidents or rockfall conditions. The breached WP may release its gaseous and volatile radionuclide content to the subsurface environment and result in contaminating the subsurface facility. The scope of this analysis is limited to radioactive contaminants resulting from breached WPs during the preclosure period of the subsurface repository. This report: (1) documents a method for deriving LRCL on the external surfaces of WP for acceptance into the subsurface repository; (2) provides a table of derived LRCL for nuclides of radiological importance; (3) Provides an as low as is reasonably achievable (ALARA) evaluation of the derived LRCL by comparing potential onsite and offsite doses to documented ALARA requirements; (4) Provides a method for estimating potential releases from a defective WP; (5) Provides an evaluation of potential radioactive releases from a defective WP that may become airborne and result in contamination of the subsurface facility; and (6) Provides a preliminary analysis of the detectability of a potential WP leak to support the design of an airborne release monitoring system.« less

SIRE: A MIMO Radar for Landmine/IED Detection

DTIC Science & Technology

2013-04-30

pursuit) for image formation. This technique has been used for subsurface imaging in the image domain, producing ’CLEANer’ images (where prior knowledge...Astronomy and Astrophysics Supplement 15 (1974). [22] Karpat, E., “CLEAN technique to classify and detect objects in subsurface imaging ,” International

Investigation of the sensitivity of a cross-polarized light visualization system to detect subclinical erythema and dryness in women with vulvovaginitis.

PubMed

Farage, Miranda A; Singh, Mukul; Ledger, William J

2009-07-01

An enhanced visualization technique using polarized light (Syris v600 enhanced visualization system; Syris Scientific LLC, Gray, ME) detects surface and subsurface ( approximately 1 mm depth) inflammation. We sought to compare the Syris v600 system with unaided visual inspection and colposcopy of the female genitalia. Erythema and dryness of the vulva, introitus, vagina, and cervix were visualized and scored by each method in patients with and without vulvitis. Subsurface visualization was more sensitive in detecting genital erythema and dryness at all sites whether or not symptoms were present. Subsurface inflammation of the introitus, vagina, and cervix only was detected uniquely in women with vulvar vestibulitis syndrome (VVS). A subset of women presenting with VVS exhibited subclinical inflammation of the vulva vestibule and vagina (designated VVS/lichen sclerosus subgroup). Enhanced visualization of the genital epithelial subsurface with cross-polarized light may assist in diagnosing subclinical inflammation in vulvar conditions heretofore characterized as sensory syndromes.

Using electrokinetic phenomena and electrical resistance tomography to characterize the movement of subsurface fluids

DOEpatents

Ramirez, Abelardo L.; Cooper, John F.; Daily, William D.

1996-01-01

This invention relates generally to the remote detections of subsurface liquid contaminants using in combination a geophysical technique known as ERT and an EKS. Electrokinetic transport is used to enhance the ability of electrical resistance tomography (ERT) to detect position and movement of subsurface contaminant liquids, particles or ions. ERT images alone are difficult to interpret because of natural inhomogeneities in soil composition and electrical properties. By subtracting two or more ERT images obtained before and after field induced movement, a high contrast image of a plume of distinct electrokinetic properties can be seen. The invention is applicable to important subsurface characterization problems including, as examples, (1) detection of liquid-saturated plumes of contaminants such as those associated with leaks from underground storage tanks containing hazardous concentrated electrolytes, (2) detection and characterization of soils contaminated with organic pollutants such as droplets of gasoline; and (3) monitoring the progress of electrokinetic containment or clean up of underground contamination.

Using electrokinetic phenomena and electrical resistance tomography to characterize the movement of subsurface fluids

DOEpatents

Ramirez, A.L.; Cooper, J.F.; Daily, W.D.

1996-02-27

This invention relates generally to the remote detections of subsurface liquid contaminants using in combination a geophysical technique known as ERT and an EKS. Electrokinetic transport is used to enhance the ability of electrical resistance tomography (ERT) to detect position and movement of subsurface contaminant liquids, particles or ions. ERT images alone are difficult to interpret because of natural inhomogeneities in soil composition and electrical properties. By subtracting two or more ERT images obtained before and after field induced movement, a high contrast image of a plume of distinct electrokinetic properties can be seen. The invention is applicable to important subsurface characterization problems including, as examples, (1) detection of liquid-saturated plumes of contaminants such as those associated with leaks from underground storage tanks containing hazardous concentrated electrolytes, (2) detection and characterization of soils contaminated with organic pollutants such as droplets of gasoline; and (3) monitoring the progress of electrokinetic containment or clean up of underground contamination. 1 fig.

The hydrological response of a small catchment after the abandonment of terrace cultivation. A study case in northwestern Spain

NASA Astrophysics Data System (ADS)

Llorente-Adán, Jose A.; Lana-Renault, Noemí; Galilea, Ianire; Ruiz-Flaño, Purificacion

2015-04-01

Terrace construction for cultivation results in a complete transformation of the hillslopes to a series of flat sectors and almost vertical steps. This strategy, which involves a redistribution of soils and a re-organization of the drainage network, provides fertile soil over steep slopes, improves infiltration and controls overland flow under conditions of intense rainstorms. In Camero Viejo (north-western Iberian ranges) most of the hillslopes are occupied by terraced fields. During the XXth century, rural population declined and agricultural practices were abandoned. In this area, a small catchment (1.9 km2) was monitored in 2012 for studying how the abandonment of agricultural terraces affect water and sediment transfer from the hillslopes to the channels. Terraces occupy 40% of the catchment and are covered by sparse grass and shrubs. The equipment installed in the catchment registers continuously meteorological data, discharge and water table fluctuations. Data on suspended sediment transport is obtained by means of a rising-stage sampler. Here we present the hydrological results corresponding to the years 2012-13 and 2013-14. The hydrological response of the catchment was moderate (annual runoff coefficient < 0.20), which could be in part explained by the high evapotranspiration rates reported in the area. Lows flows were recorded in summer and autumn, when the water reserves of the catchment were dry, and high flows occurred from January, when the catchment became wetter. The shape of the hydrographs, with slow response times, moderate peakflows and long recession limbs suggested a large contribution of subsurface flow, probably favored by deep and well structured soils in the bench terraces. Soil saturation areas were not observed during the study period, suggesting that soil infiltration processes and subsurface flow are important, and that the drainage system of the terraces is probably well maintained. No suspended sediment has been collected so far, confirming the hypothesis that subsurface flow might be a dominant runoff generation process.

Use of Large-Scale Multi-Configuration EMI Measurements to Characterize Subsurface Structures of the Vadose Zone.

NASA Astrophysics Data System (ADS)

Huisman, J. A.; Brogi, C.; Pätzold, S.; Weihermueller, L.; von Hebel, C.; Van Der Kruk, J.; Vereecken, H.

2017-12-01

Subsurface structures of the vadose zone can play a key role in crop yield potential, especially during water stress periods. Geophysical techniques like electromagnetic induction EMI can provide information about dominant shallow subsurface features. However, previous studies with EMI have typically not reached beyond the field scale. We used high-resolution large-scale multi-configuration EMI measurements to characterize patterns of soil structural organization (layering and texture) and their impact on crop productivity at the km2 scale. We collected EMI data on an agricultural area of 1 km2 (102 ha) near Selhausen (NRW, Germany). The area consists of 51 agricultural fields cropped in rotation. Therefore, measurements were collected between April and December 2016, preferably within few days after the harvest. EMI data were automatically filtered, temperature corrected, and interpolated onto a common grid of 1 m resolution. Inspecting the ECa maps, we identified three main sub-areas with different subsurface heterogeneity. We also identified small-scale geomorphological structures as well as anthropogenic activities such as soil management and buried drainage networks. To identify areas with similar subsurface structures, we applied image classification techniques. We fused ECa maps obtained with different coil distances in a multiband image and applied supervised and unsupervised classification methodologies. Both showed good results in reconstructing observed patterns in plant productivity and the subsurface structures associated with them. However, the supervised methodology proved more efficient in classifying the whole study area. In a second step, we selected hundred locations within the study area and obtained a soil profile description with type, depth, and thickness of the soil horizons. Using this ground truth data it was possible to assign a typical soil profile to each of the main classes obtained from the classification. The proposed methodology was effective in producing a high resolution subsurface model in a large and complex study area that extends well beyond the field scale.

Information technology and innovative drainage management practices for selenium load reduction from irrigated agriculture to provide stakeholder assurances and meet contaminant mass loading policy objectives

DOE Office of Scientific and Technical Information (OSTI.GOV)

Quinn, N.W.T.

2009-10-15

Many perceive the implementation of environmental regulatory policy, especially concerning non-point source pollution from irrigated agriculture, as being less efficient in the United States than in many other countries. This is partly a result of the stakeholder involvement process but is also a reflection of the inability to make effective use of Environmental Decision Support Systems (EDSS) to facilitate technical information exchange with stakeholders and to provide a forum for innovative ideas for controlling non-point source pollutant loading. This paper describes one of the success stories where a standardized Environmental Protection Agency (EPA) methodology was modified to better suit regulationmore » of a trace element in agricultural subsurface drainage and information technology was developed to help guide stakeholders, provide assurances to the public and encourage innovation while improving compliance with State water quality objectives. The geographic focus of the paper is the western San Joaquin Valley where, in 1985, evapoconcentration of selenium in agricultural subsurface drainage water, diverted into large ponds within a federal wildlife refuge, caused teratogenecity in waterfowl embryos and in other sensitive wildlife species. The fallout from this environmental disaster was a concerted attempt by State and Federal water agencies to regulate non-point source loads of the trace element selenium. The complexity of selenium hydrogeochemistry, the difficulty and expense of selenium concentration monitoring and political discord between agricultural and environmental interests created challenges to the regulation process. Innovative policy and institutional constructs, supported by environmental monitoring and the web-based data management and dissemination systems, provided essential decision support, created opportunities for adaptive management and ultimately contributed to project success. The paper provides a retrospective on the contentious planning process and offers suggestions as to how the technical and institutional issues could have been resolved faster through early adoption of some of the core principles of sound EDSS design.« less

Control of groundwater in surface mining

NASA Astrophysics Data System (ADS)

Brawner, C. O.

1982-03-01

The presence of groundwater in surface mining operations often creates serious problems. The most important is generally a reduction in stability of the pit slopes. This is caused by pore water pressures and hydrodynamic shock due to blasting which reduce the shear strength and seepage pressures, water in tension cracks and increased unit weight which increase the shear stress. Groundwater and seepage also increase the cost of pit drainage, shipping, drilling and blasting, tyre wear and equipment maintenance. Surface erosion may also be increased and, in northern climates, ice flows on the slopes may occur. Procedures have been developed in the field of soil mechanics and engineering of dams to obtain quantitative data on pore water pressures and rock permeability, to evaluate the influence of pore water and seepage pressures on stability and to estimate the magnitude of ground-water flow. Based on field investigations, a design can be prepared for the control of groundwater in the slope and in the pit. Methods of control include the use of horizontal drains, blasted toe drains, construction of adits or drainage tunnels and pumping from wells in or outside of the pit. Recent research indicates that subsurface drainage can be augmented by applying a vacuum or by selective blasting. Instrumentation should be installed to monitor the groundwater changes created by drainage. Typical case histories are described that indicate the approach used to evaluate groundwater conditions.

Preliminary assessment of the effects of selenium in agricultural drainage on fish in the San Joaquin Valley

USGS Publications Warehouse

Saiki, M.K.; Jennings, M.R.; Hamilton, S.J.; Dinar, A.; Zilberman, D.

1991-01-01

Concentrations of total selenium were measured in whole-body samples of seven fishes from the Sacramento and San Joaquin River systems and the San Francisco Bay complex. Concentrations of selenium (up to 11 µg/g dry weight in whole-body composite samples) were highest in fish from canals and sloughs in the Grassland Water District (Grasslands) that received large inflows of subsurface agricultural drainage water. Slightly lower selenium concentrations occurred in fish from the San Joaquin River immediately downstream from tributaries draining the Grasslands. Although circumstantial evidence suggests that selenium-sensitive species such as bluegills and largemouth bass are being excluded from the Grasslands, conclusive evidence of selenium toxicity is still lacking. In response to earlier reports of high concentrations of selenium in several species collected from the Grasslands, the California Department of Health Services has urged people to limit consumption of fish from this region.

Hydrogeologic data from a shallow flooding demonstration project, Twitchell Island, California, 1997-2001

USGS Publications Warehouse

Gamble, James M.; Burow, Karen R.; Wheeler, Gail A.; Hilditch, Robert; Drexler, Judy Z.

2003-01-01

Data were collected during a study to determine the effects of continuous shallow flooding on ground-water discharge to an agricultural drainage ditch on Twitchell Island, California. The conceptual model of the hydrogeologic setting was detailed with soil coring and borehole-geophysical logs. Twenty-two monitoring wells were installed to observe hydraulic head. Ten aquifer slug tests were done in peat and mineral sediments. Ground-water and surface-water temperature was monitored at 14 locations. Flow to and from the pond was monitored through direct measurement of flows and through the calculation of a water budget. These data were gathered to support the development of a two-dimensional ground-water flow model. The model will be used to estimate subsurface discharge to the drainage ditch as a result of the pond. The estimated discharge will be used to estimate the concentrations of DOC that can be expected in the ditch.

Mineralogy from Cores in Prospect Gulch, San Juan County, Colorado

USGS Publications Warehouse

Bove, Dana J.; Johnson, Raymond H.; Yager, Douglas B.

2007-01-01

In the late nineteenth century, San Juan County, Colorado, was the center of a metal mining boom in the San Juan Mountains. Although most mining activity ceased by the 1990s, the effects of historical mining continue to contribute metals to ground water and surface water. Previous research by the U.S. Geological Survey identified ground-water discharge as a significant pathway for the loading of metals to surface water from both acid-mine drainage and acid-rock drainage. In an effort to understand the ground-water flow system in the upper Animas River watershed, Prospect Gulch was selected for further study because of the amount of previous data provided in and around that particular watershed. In support of this ground-water research effort, data was collected from drill core, which included: (1) detailed descriptions of the subsurface geology and hydrothermal alteration patterns, (2) depth of sulfide oxidation, and (3) quantitative mineralogy.

High-frequency monitoring of water fluxes and nutrient loads to assess the effects of controlled drainage on water storage and nutrient transport

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rozemeijer, J. C.; Visser, A.; Borren, W.

High nitrogen (N) and phosphorus (P) fluxes from upstream agriculture threaten aquatic ecosystems in surface waters and estuaries, especially in areas characterized by high agricultural N and P inputs and densely drained catchments like the Netherlands. Controlled drainage has been recognized as an effective option to optimize soil moisture conditions for agriculture and to reduce unnecessary losses of fresh water and nutrients. This is achieved by introducing control structures with adjustable overflow levels into subsurface tube drain systems. A small-scale (1 ha) field experiment was designed to investigate the hydrological and chemical changes after introducing controlled drainage. Precipitation rates andmore » the response of water tables and drain fluxes were measured in the periods before the introduction of controlled drainage (2007–2008) and after (2009–2011). For the N and P concentration measurements, auto-analyzers for continuous records were combined with passive samplers for time-averaged concentrations at individual drain outlets. The experimental setup enabled the quantification of changes in the water and solute balance after introducing controlled drainage. The results showed that introducing controlled drainage reduced the drain discharge and increased the groundwater storage in the field. To achieve this, the overflow levels have to be elevated in early spring, before the drain discharge stops due to dryer conditions and falling groundwater levels. The groundwater storage in the field would have been larger if the water levels in the adjacent ditch were controlled as well by an adjustable weir. The N concentrations and loads increased, which was largely related to elevated concentrations in one of the three monitored tube drains. The P loads via the tube drains reduced due to the reduction in discharge after introducing controlled drainage. Furthermore, this may be counteracted by the higher groundwater levels and the larger contribution of N- and P-rich shallow groundwater and overland flow to the surface water.« less

High-frequency monitoring of water fluxes and nutrient loads to assess the effects of controlled drainage on water storage and nutrient transport

DOE PAGES

Rozemeijer, J. C.; Visser, A.; Borren, W.; ...

2016-01-19

High nitrogen (N) and phosphorus (P) fluxes from upstream agriculture threaten aquatic ecosystems in surface waters and estuaries, especially in areas characterized by high agricultural N and P inputs and densely drained catchments like the Netherlands. Controlled drainage has been recognized as an effective option to optimize soil moisture conditions for agriculture and to reduce unnecessary losses of fresh water and nutrients. This is achieved by introducing control structures with adjustable overflow levels into subsurface tube drain systems. A small-scale (1 ha) field experiment was designed to investigate the hydrological and chemical changes after introducing controlled drainage. Precipitation rates andmore » the response of water tables and drain fluxes were measured in the periods before the introduction of controlled drainage (2007–2008) and after (2009–2011). For the N and P concentration measurements, auto-analyzers for continuous records were combined with passive samplers for time-averaged concentrations at individual drain outlets. The experimental setup enabled the quantification of changes in the water and solute balance after introducing controlled drainage. The results showed that introducing controlled drainage reduced the drain discharge and increased the groundwater storage in the field. To achieve this, the overflow levels have to be elevated in early spring, before the drain discharge stops due to dryer conditions and falling groundwater levels. The groundwater storage in the field would have been larger if the water levels in the adjacent ditch were controlled as well by an adjustable weir. The N concentrations and loads increased, which was largely related to elevated concentrations in one of the three monitored tube drains. The P loads via the tube drains reduced due to the reduction in discharge after introducing controlled drainage. Furthermore, this may be counteracted by the higher groundwater levels and the larger contribution of N- and P-rich shallow groundwater and overland flow to the surface water.« less

High-frequency monitoring of water fluxes and nutrient loads to assess the effects of controlled drainage on water storage and nutrient transport

NASA Astrophysics Data System (ADS)

Rozemeijer, J. C.; Visser, A.; Borren, W.; Winegram, M.; van der Velde, Y.; Klein, J.; Broers, H. P.

2016-01-01

High nitrogen (N) and phosphorus (P) fluxes from upstream agriculture threaten aquatic ecosystems in surface waters and estuaries, especially in areas characterized by high agricultural N and P inputs and densely drained catchments like the Netherlands. Controlled drainage has been recognized as an effective option to optimize soil moisture conditions for agriculture and to reduce unnecessary losses of fresh water and nutrients. This is achieved by introducing control structures with adjustable overflow levels into subsurface tube drain systems. A small-scale (1 ha) field experiment was designed to investigate the hydrological and chemical changes after introducing controlled drainage. Precipitation rates and the response of water tables and drain fluxes were measured in the periods before the introduction of controlled drainage (2007-2008) and after (2009-2011). For the N and P concentration measurements, auto-analyzers for continuous records were combined with passive samplers for time-averaged concentrations at individual drain outlets. The experimental setup enabled the quantification of changes in the water and solute balance after introducing controlled drainage. The results showed that introducing controlled drainage reduced the drain discharge and increased the groundwater storage in the field. To achieve this, the overflow levels have to be elevated in early spring, before the drain discharge stops due to dryer conditions and falling groundwater levels. The groundwater storage in the field would have been larger if the water levels in the adjacent ditch were controlled as well by an adjustable weir. The N concentrations and loads increased, which was largely related to elevated concentrations in one of the three monitored tube drains. The P loads via the tube drains reduced due to the reduction in discharge after introducing controlled drainage. However, this may be counteracted by the higher groundwater levels and the larger contribution of N- and P-rich shallow groundwater and overland flow to the surface water.

Managing tile drainage, subirrigation, and nitrogen fertilization to enhance crop yields and reduce nitrate loss.

PubMed

Drury, C F; Tan, C S; Reynolds, W D; Welacky, T W; Oloya, T O; Gaynor, J D

2009-01-01

Improving field-crop use of fertilizer nitrogen is essential for protecting water quality and increasing crop yields. The objective of this study was to determine the effectiveness of controlled tile drainage (CD) and controlled tile drainage with subsurface irrigation (CDS) for mitigating off-field nitrate losses and enhancing crop yields. The CD and CDS systems were compared on a clay loam soil to traditional unrestricted tile drainage (UTD) under a corn (Zea Mays L.)-soybean (Glycine Max. (L.) Merr.) rotation at two nitrogen (N) fertilization rates (N1: 150 kg N ha(-1) applied to corn, no N applied to soybean; N2: 200 kg N ha(-1) applied to corn, 50 kg N ha(-1) applied to soybean). The N concentrations in tile flow events with the UTD treatment exceeded the provisional long-term aquatic life limit (LT-ALL) for freshwater (4.7 mg N L(-1)) 72% of the time at the N1 rate and 78% at the N2 rate, whereas only 24% of tile flow events at N1 and 40% at N2 exceeded the LT-ALL for the CDS treatment. Exceedances in N concentration for surface runoff and tile drainage were greater during the growing season than the non-growing season. At the N1 rate, CD and CDS reduced average annual N losses via tile drainage by 44 and 66%, respectively, relative to UTD. At the N2 rate, the average annual decreases in N loss were 31 and 68%, respectively. Crop yields from CDS were increased by an average of 2.8% relative to UTD at the N2 rate but were reduced by an average of 6.5% at the N1 rate. Hence, CD and CDS were effective for reducing average nitrate losses in tile drainage, but CDS increased average crop yields only when additional N fertilizer was applied.

Method for identifying subsurface fluid migration and drainage pathways in and among oil and gas reservoirs using 3-D and 4-D seismic imaging

DOEpatents

Anderson, R.N.; Boulanger, A.; Bagdonas, E.P.; Xu, L.; He, W.

1996-12-17

The invention utilizes 3-D and 4-D seismic surveys as a means of deriving information useful in petroleum exploration and reservoir management. The methods use both single seismic surveys (3-D) and multiple seismic surveys separated in time (4-D) of a region of interest to determine large scale migration pathways within sedimentary basins, and fine scale drainage structure and oil-water-gas regions within individual petroleum producing reservoirs. Such structure is identified using pattern recognition tools which define the regions of interest. The 4-D seismic data sets may be used for data completion for large scale structure where time intervals between surveys do not allow for dynamic evolution. The 4-D seismic data sets also may be used to find variations over time of small scale structure within individual reservoirs which may be used to identify petroleum drainage pathways, oil-water-gas regions and, hence, attractive drilling targets. After spatial orientation, and amplitude and frequency matching of the multiple seismic data sets, High Amplitude Event (HAE) regions consistent with the presence of petroleum are identified using seismic attribute analysis. High Amplitude Regions are grown and interconnected to establish plumbing networks on the large scale and reservoir structure on the small scale. Small scale variations over time between seismic surveys within individual reservoirs are identified and used to identify drainage patterns and bypassed petroleum to be recovered. The location of such drainage patterns and bypassed petroleum may be used to site wells. 22 figs.

Method for identifying subsurface fluid migration and drainage pathways in and among oil and gas reservoirs using 3-D and 4-D seismic imaging

DOEpatents

Anderson, Roger N.; Boulanger, Albert; Bagdonas, Edward P.; Xu, Liqing; He, Wei

1996-01-01

The invention utilizes 3-D and 4-D seismic surveys as a means of deriving information useful in petroleum exploration and reservoir management. The methods use both single seismic surveys (3-D) and multiple seismic surveys separated in time (4-D) of a region of interest to determine large scale migration pathways within sedimentary basins, and fine scale drainage structure and oil-water-gas regions within individual petroleum producing reservoirs. Such structure is identified using pattern recognition tools which define the regions of interest. The 4-D seismic data sets may be used for data completion for large scale structure where time intervals between surveys do not allow for dynamic evolution. The 4-D seismic data sets also may be used to find variations over time of small scale structure within individual reservoirs which may be used to identify petroleum drainage pathways, oil-water-gas regions and, hence, attractive drilling targets. After spatial orientation, and amplitude and frequency matching of the multiple seismic data sets, High Amplitude Event (HAE) regions consistent with the presence of petroleum are identified using seismic attribute analysis. High Amplitude Regions are grown and interconnected to establish plumbing networks on the large scale and reservoir structure on the small scale. Small scale variations over time between seismic surveys within individual reservoirs are identified and used to identify drainage patterns and bypassed petroleum to be recovered. The location of such drainage patterns and bypassed petroleum may be used to site wells.

Subsurface damage detection in non-ferrous systems using 3D synchronous magnetic inspection

NASA Astrophysics Data System (ADS)

Gray, David; Berry, David

2018-04-01

Prime Photonics is developing a non-destructive inspection (NDI) technology, 3-D synchronous magnetic imaging system (3-D SMIS), that uses synchronous detection of magnetic signatures resulting from ultrasonic excitation to measure both surface and subsurface flaws in conductive structures. 3-D SMIS is showing promise in a wide range of NDI/NDE uses including characterizing surface-breaking cracks in ferrous and non-ferrous materials, locating and characterizing subsurface cracks within nonferrous conductive materials (Ti 6-4 and carbon fiber composites), and characterization of subsurface residual stresses. The technology offers a non-contact, high resolution inspection technique that does not require austere environments, and can accommodate non-planar specimen geometries.

Preoperative endoscopic versus percutaneous transhepatic biliary drainage in potentially resectable perihilar cholangiocarcinoma (DRAINAGE trial): design and rationale of a randomized controlled trial.

PubMed

Wiggers, Jimme K; Coelen, Robert J S; Rauws, Erik A J; van Delden, Otto M; van Eijck, Casper H J; de Jonge, Jeroen; Porte, Robert J; Buis, Carlijn I; Dejong, Cornelis H C; Molenaar, I Quintus; Besselink, Marc G H; Busch, Olivier R C; Dijkgraaf, Marcel G W; van Gulik, Thomas M

2015-02-14

Liver surgery in perihilar cholangiocarcinoma (PHC) is associated with high postoperative morbidity because the tumor typically causes biliary obstruction. Preoperative biliary drainage is used to create a safer environment prior to liver surgery, but biliary drainage may be harmful when severe drainage-related complications deteriorate the patients' condition or increase the risk of postoperative morbidity. Biliary drainage can cause cholangitis/cholecystitis, pancreatitis, hemorrhage, portal vein thrombosis, bowel wall perforation, or dehydration. Two methods of preoperative biliary drainage are mostly applied: endoscopic biliary drainage, which is currently used in most regional centers before referring patients for surgical treatment, and percutaneous transhepatic biliary drainage. Both methods are associated with severe drainage-related complications, but two small retrospective series found a lower incidence in the number of preoperative complications after percutaneous drainage compared to endoscopic drainage (18-25% versus 38-60%, respectively). The present study randomizes patients with potentially resectable PHC and biliary obstruction between preoperative endoscopic or percutaneous transhepatic biliary drainage. The study is a multi-center trial with an "all-comers" design, randomizing patients between endoscopic or percutaneous transhepatic biliary drainage. All patients selected to potentially undergo a major liver resection for presumed PHC are eligible for inclusion in the study provided that the biliary system in the future liver remnant is obstructed (even if they underwent previous inadequate endoscopic drainage). Primary outcome measure is the total number of severe preoperative complications between randomization and exploratory laparotomy. The study is designed to detect superiority of percutaneous drainage: a provisional sample size of 106 patients is required to detect a relative decrease of 50% in the number of severe preoperative complications (alpha = 0.95; beta = 0.8). Interim analysis after inclusion of 53 patients (50%) will provide the definitive sample size. Secondary outcome measures encompass the success of biliary drainage, quality of life, and postoperative morbidity and mortality. The DRAINAGE trial is designed to identify a difference in the number of severe drainage-related complications after endoscopic and percutaneous transhepatic biliary drainage in patients selected to undergo a major liver resection for perihilar cholangiocarcinoma. Netherlands Trial Register [ NTR4243 , 11 October 2013].

Neotectonic Activity from the Upper Reaches of the Arabian Gulf and Possibilities of New Oil Fields

NASA Astrophysics Data System (ADS)

Sissakian, V. K.; Abdul Ahad, A. D.; Al-Ansari, N.; Knutsson, S.

2018-03-01

Upper reaches of the Arabian Gulf consist of different types of fine sediments including the vast Mesopotamia Plain sediments, tidal flat sediments and estuarine sabkha sediments. The height of the plain starts from zero meter and increases northwards to three meters with extremely gentle gradient. The vast plain to the north of the Arabian Gulf is drained by Shat Al-Arab (Shat means river in Iraqi slang language) and Khor Al-Zubair (Khor means estuary). The former drains the extreme eastern part of the plain; whereas, the latter drains the western part. Shat Al-Arab is the resultant of confluence of the Tigris and Euphrates rivers near Al-Qurna town; about 160 km north of the Arabian Gulf mouth at Al-Fao town; whereas, the length of Khor Al-Zubair is about 50 km; as measured from Um Qasir Harbor. The drainage system around Khor Al-Zubair is extremely fine dendritic; whereas around Shat Al-Arab is almost parallel running from both sides of the river towards the river; almost perpendicularly. The fine dendritic drainage around Khor Al-Zubair shows clear recent erosional activity, beside water divides, abandoned irrigation channels and dislocated irrigational channels and estuarine distributaries; all are good indication for a Neotectonic activity in the region. These may indicate the presence of subsurface anticlines, which may represent oil fields; since tens of subsurface anticlines occur in near surroundings, which are oil fields.

Spatial variation in the bacterial and denitrifying bacterial community in a biofilter treating subsurface agricultural drainage.

PubMed

Andrus, J Malia; Porter, Matthew D; Rodríguez, Luis F; Kuehlhorn, Timothy; Cooke, Richard A C; Zhang, Yuanhui; Kent, Angela D; Zilles, Julie L

2014-02-01

Denitrifying biofilters can remove agricultural nitrates from subsurface drainage, reducing nitrate pollution that contributes to coastal hypoxic zones. The performance and reliability of natural and engineered systems dependent upon microbially mediated processes, such as the denitrifying biofilters, can be affected by the spatial structure of their microbial communities. Furthermore, our understanding of the relationship between microbial community composition and function is influenced by the spatial distribution of samples.In this study we characterized the spatial structure of bacterial communities in a denitrifying biofilter in central Illinois. Bacterial communities were assessed using automated ribosomal intergenic spacer analysis for bacteria and terminal restriction fragment length polymorphism of nosZ for denitrifying bacteria.Non-metric multidimensional scaling and analysis of similarity (ANOSIM) analyses indicated that bacteria showed statistically significant spatial structure by depth and transect,while denitrifying bacteria did not exhibit significant spatial structure. For determination of spatial patterns, we developed a package of automated functions for the R statistical environment that allows directional analysis of microbial community composition data using either ANOSIM or Mantel statistics.Applying this package to the biofilter data, the flow path correlation range for the bacterial community was 6.4 m at the shallower, periodically in undated depth and 10.7 m at the deeper, continually submerged depth. These spatial structures suggest a strong influence of hydrology on the microbial community composition in these denitrifying biofilters. Understanding such spatial structure can also guide optimal sample collection strategies for microbial community analyses.

Selenium and other elements in freshwater fishes from the irrigated San Joaquin Valley, California

USGS Publications Warehouse

Saiki, M.K.; Jennings, M.R.; May, T.W.

1992-01-01

Arsenic (As), chromium (Cr), mercury (Hg), and selenium (Se) were measured in composite whole-body samples of five fishes — bluegill (Lepomis macrochirus), common carp (Cyprinus carpio), mosquitofish (Gambusia affinis), largemouth bass (Micropterus salmoides), and Sacramento blackfish (Orthodon microlepidotus) — from the San Joaquin River system to determine if concentrations were elevated from exposure to agricultural subsurface (tile) drainage. Except for Cr, the concentrations of these elements in fishes from one or more sites were elevated; however, only Se approached concentrations that may adversely affect survival, growth, or reproduction in warm water fishes. Moreover, only Se among the four measured elements exhibited a geographic (spatial) pattern that coincided with known inflows of tile drainage to the San Joaquin River and its tributaries. Historical data from the Grassland Water District (Grasslands; a region exposed to concentrated tile drainage) suggested that concentrations of Se in fishes were at maximum during or shortly after 1984 and have been slightly lower since then. The recent decline of Se concentrations in fishes from the Grasslands could be temporary if additional acreages of irrigated lands in this portion of the San Joaquin Valley must be tile-drained to protect agricultural crops from rising groundwater tables.

Device and nondestructive method to determine subsurface micro-structure in dense materials

DOEpatents

Sun, Jiangang [Westmont, IL

2006-05-09

A method and a device to detect subsurface three-dimensional micro-structure in a sample by illuminating the sample with light of a given polarization and detecting light emanating from the sample that has a different direction of polarization by means of a confocal optical system.

EVALUATION OF GEOPHYSICAL METHODS FOR THE DETECTION OF SUBSURFACE TETRACHLOROETHYLENE IN CONTROLLED SPILL EXPERIMENTS

EPA Science Inventory

The purpose of the work was to determine the capability of various geophysical methods to detect PCE in the subsurface. Measurements were made with ten different geophysical techniques before, during, and after the PCE injection. This approach provided a clear identification of a...

Amylase, lipase, and volume of drainage fluid in gastrectomy for the early detection of complications caused by pancreatic leakage.

PubMed

Seo, Kyung Won; Yoon, Ki Young; Lee, Sang Ho; Shin, Yeon Myung; Choi, Kyung Hyun; Hwang, Hyun Yong

2011-12-01

Pancreatic leakage is a serious complication of gastrectomy due to stomach cancer. Therefore, we analyzed amylase and lipase concentrations in blood and drainage fluid, and evaluated the volume of drainage fluid to discern their usefulness as markers for the early detection of serious pancreatic leakage requiring reoperation after gastrectomy. From January 2001 to December 2007, we retrospectively analyzed data from 24,072 patient samples. We divided patients into two groups; 1) complications with pancreatic leakage (CG), and 2) no complications associated with pancreatic leakage (NCG). Values of amylase and lipase in the blood and drainage fluid, volume of the drainage fluid, and relationships among the volumes, amylase values, and lipase values in the drainage fluid were evaluated, respectively in the two groups. The mean amylase values of CG were significantly higher than those of NCG in blood and drainage fluid (P < 0.05). For lipase, statistically significant differences were observed in drainage fluid (P < 0.05). The mean volume (standard deviation) of the drained fluid through the tube between CG (n = 22) and NCG (n = 236) on postoperative day 1 were 368.41 (266.25) and 299.26 (300.28), respectively. There were no statistically significant differences between the groups (P = 0.298). There was a correlation between the amylase and lipase values in the drainage fluid (r = 0.812, P = 0.000). Among postoperative amylase and lipase values in blood and drainage fluid, and the volume of drainage fluid, the amylase in drainage fluid was better differentiated between CG and NCG than other markers. The volume of the drainage fluid did not differ significantly between groups.

Hydrological Controls on Nutrient Concentrations and Fluxes in Agricultural Catchments

NASA Astrophysics Data System (ADS)

Petry, J.; Soulsby, C.

2002-12-01

This investigation into diffuse agricultural pollution and the hydrological controls that exert a strong influence on both nutrient concentrations and fluxes, was conducted in an intensively farmed lowland catchment in north-east Scotland. The study focuses on spatial and seasonal variations in nutrient concentrations and fluxes at the catchment scale, over a 15-month period. The water quality of the 14.5 km2 Newmills Burn catchment has relatively high nutrient levels with mean concentrations of NO3-N and NH3-N at 6.09 mg/l and 0.28 mg/l respectively. Average PO4-P concentrations are 0.06 mg/l. Over short timescales nutrient concentrations and fluxes are greatest during storm events when PO4-P and NH3-N are mobilised by overland flow in riparian areas, where soils have been compacted by livestock or machinery. Delivery of deeper soil water in subsurface storm flow, facilitated by agricultural under-drainage, produces a marked increase in NO3-N (6.9 mg/l) concentrations on the hydrograph recession limb. A more detailed insight into the catchment response to storm events, and in particular the response of the hydrological pathways which provide the main sources of runoff during storm events, was gained by sampling stream water at 2-hourly intervals during 5 events. End Member Mixing Analysis (EMMA) was carried out using event specific end-member chemistries to differentiate three catchment-scale hydrological pathways (overland flow, subsurface storm flow, groundwater flow) on the basis of observed Si and NO3-N concentrations in sampled source waters. Results show that overland flow generally dominates the storm peak and provides the main flow path by which P is transferred to stream channels during storm events, whilst subsurface storm flows usually dominate the storm hydrograph volumetrically and route NO3-rich soil water to the stream. The study shows that altering hydrological pathways in a catchment can have implications for nutrient management. Whilst buffer strips can reduce the delivery of NH3-N and PO4-P by overland flow to stream channels during storm events, the management of N-rich storm runoff as NO3 via sub-surface drains would require significant interference with the drainage network. This could have a negative impact on agricultural production in the catchment.

Factors Affecting Nitrate Delivery to Streams from Shallow Ground Water in the North Carolina Coastal Plain

USGS Publications Warehouse

Harden, Stephen L.; Spruill, Timothy B.

2008-01-01

An analysis of data collected at five flow-path study sites between 1997 and 2006 was performed to identify the factors needed to formulate a comprehensive program, with a focus on nitrogen, for protecting ground water and surface water in the North Carolina Coastal Plain. Water-quality protection in the Coastal Plain requires the identification of factors that affect the transport of nutrients from recharge areas to streams through the shallow ground-water system. Some basins process or retain nitrogen more readily than others, and the factors that affect nitrogen processing and retention were the focus of this investigation to improve nutrient management in Coastal Plain streams and to reduce nutrient loads to coastal waters. Nitrate reduction in ground water was observed at all five flow-path study sites in the North Carolina Coastal Plain, although the extent of reduction at each site was influenced by various environmental, hydrogeologic, and geochemical factors. Denitrification was the most common factor responsible for decreases in nitrate along the ground-water flow paths. Specific factors, some of which affect denitrification rates, that appeared to influence ground-water nitrate concentrations along the flow paths or in the streams include soil drainage, presence or absence of riparian buffers, evapotranspiration, fertilizer use, ground-water recharge rates and residence times, aquifer properties, subsurface tile drainage, sources and amounts of organic matter, and hyporheic processes. The study data indicate that the nitrate-reducing capacity of the buffer zone combined with that of the hyporheic zone can substantially lower the amount of ground-water nitrate discharged to streams in agricultural settings of the North Carolina Coastal Plain. At the watershed scale, the effects of ground-water discharge on surface-water quality appear to be greatly influenced by streamflow conditions and the presence of extensive riparian vegetation. Streamflow statistics that reflect base flow and the general hydrologic dynamics of a stream are important in understanding nutrient transport from a watershed and may be useful indicators of watersheds that are likely to have higher yields of nutrients and water. Combining streamflow statistics with information on such factors as land use, soil drainage, extent of riparian vegetation, geochemical conditions, and subsurface tile drainage in the Coastal Plain can be useful in identifying watersheds that are most likely to export excessive nitrogen due to nonpoint-source loadings and watersheds that are effective in processing nitrogen.

Heat tracer methods

USGS Publications Warehouse

Healy, Richard W.; Scanlon, Bridget R.

2010-01-01

The flow of heat in the subsurface is closely linked to the movement of water (Ingebritsen et al., 2006). As such, heat has been used as a tracer in groundwater studies for more than 100 years (Anderson, 2005). As with chemical and isotopic tracers (Chapter 7), spatial or temporal trends in surface and subsurface temperatures can be used to infer rates of water movement. Temperature can be measured accurately, economically, at high frequencies, and without the need to obtain water samples, facts that make heat an attractive tracer. Temperature measurements made over space and time can be used to infer rates of recharge from a stream or other surface water body (Lapham, 1989; Stonestrom and Constantz, 2003); measurements can also be used to estimate rates of steady drainage through depth intervals within thick unsaturated zones (Constantz et al., 2003; Shan and Bodvarsson, 2004). Several thorough reviews of heat as a tracer in hydrologic studies have recently been published (Constantz et al., 2003; Stonestrom and Constantz, 2003; Anderson, 2005; Blasch et al., 2007; Constantz et al., 2008). This chapter summarizes heat-tracer approaches that have been used to estimate recharge.Some clarification in terminology is presented here to avoid confusion in descriptions of the various approaches that follow. Diffuse recharge is that which occurs more or less uniformly across large areas in response to precipitation, infiltration, and drainage through the unsaturated zone. Estimates of diffuse recharge determined using measured temperatures in the unsaturated zone are referred to as potential recharge because it is possible that not all of the water moving through the unsaturated zone will recharge the aquifer; some may be lost to the atmosphere by evaporation or plant transpiration. Estimated fluxes across confining units in the saturated zone are referred to as interaquifer flow (Chapter 1). Focused recharge is that which occurs directly from a point or line source, such as a stream, on land surface. Focused recharge may vary widely in space and time. If the water table intersects a stream channel, estimates of stream loss are called actual recharge, or just recharge. If the water table lies below the stream channel, estimates are referred to as potential recharge. For simplicity, all vertical water fluxes are referred to as drainage throughout this chapter. Whether the estimated quantity represents actual or potential recharge or drainage depends on the circumstances of each individual study.

Comparison of performance of tile drainage routines in SWAT 2009 and 2012 in an extensively tile-drained watershed in the Midwest

NASA Astrophysics Data System (ADS)

Guo, Tian; Gitau, Margaret; Merwade, Venkatesh; Arnold, Jeffrey; Srinivasan, Raghavan; Hirschi, Michael; Engel, Bernard

2018-01-01

Subsurface tile drainage systems are widely used in agricultural watersheds in the Midwestern US and enable the Midwest area to become highly productive agricultural lands, but can also create environmental problems, for example nitrate-N contamination associated with drainage waters. The Soil and Water Assessment Tool (SWAT) has been used to model watersheds with tile drainage. SWAT2012 revisions 615 and 645 provide new tile drainage routines. However, few studies have used these revisions to study tile drainage impacts at both field and watershed scales. Moreover, SWAT2012 revision 645 improved the soil moisture based curve number calculation method, which has not been fully tested. This study used long-term (1991-2003) field site and river station data from the Little Vermilion River (LVR) watershed to evaluate performance of tile drainage routines in SWAT2009 revision 528 (the old routine) and SWAT2012 revisions 615 and 645 (the new routine). Both the old and new routines provided reasonable but unsatisfactory (NSE < 0.5) uncalibrated flow and nitrate loss results for a mildly sloped watershed with low runoff. The calibrated monthly tile flow, surface flow, nitrate-N in tile and surface flow, sediment and annual corn and soybean yield results from SWAT with the old and new tile drainage routines were compared with observed values. Generally, the new routine provided acceptable simulated tile flow (NSE = 0.48-0.65) and nitrate in tile flow (NSE = 0.48-0.68) for field sites with random pattern tile and constant tile spacing, while the old routine simulated tile flow and nitrate in tile flow results for the field site with constant tile spacing were unacceptable (NSE = 0.00-0.32 and -0.29-0.06, respectively). The new modified curve number calculation method in revision 645 (NSE = 0.50-0.81) better simulated surface runoff than revision 615 (NSE = -0.11-0.49). The calibration provided reasonable parameter sets for the old and new routines in the LVR watershed, and the validation results showed that the new routine has the potential to accurately simulate hydrologic processes in mildly sloped watersheds.

Layering extraction from subsurface radargrams over Greenland and the Martian NPLD by combining wavelet analysis with Hough transforms

NASA Astrophysics Data System (ADS)

Xiong, Si-Ting; Muller, Jan-Peter

2017-04-01

Extracting lines from an imagery is a solved problem in the field of edge detection. Different to images taken by camera, radargrams are a set of radar echo profiles, which record wave energy reflected by subsurface reflectors, at each location of a radar footprint along the satellite's ground track. The radargrams record where there is a dielectric contrast caused by different deposits, and other subsurface features, such as facies, and internal distributions like porosity and fluids. Among the subsurface features, layering is an important one which reflect the sequence of seasonal or yearly deposits on the ground [1-2]. In the field of image processing, line detection methods, such as the Radon Transform or Hough Transform, are able to extract these subsurface layers from rasterised versions of the echograms. However, due to the attenuation of radar waves whilst propagating through geological media, radargrams sometimes suffer from gradient and high background noise. These attributes of radargrams cause errors in detection when conventional line detection methods are directly applied. In this study, we have developed a continuous wavelet analysis technique to be applied directly to the radar echo profiles in a radargram in order to detect segmented lines, and then a conventional line detection method, such as a Hough transform can be applied to connect these segmented lines. This processing chain is tested by using datasets from a radargram acquired by the Multi-channel Coherent Radar Depth Sounder (MCoRDS) on an airborne platform in Greenland and a radargram acquired by the SHAllow RADar (SHARAD) on board the Mars Reconnaissance Orbiter (MRO) [3] over Martian North Polar Layered Deposits (NPLD). Keywords: Subsurface mapping, Radargram, SHARAD, Greenland, Martian NPLD, Subsurface layering, line detection References: [1] Phillips, R. J., et al. "Mars north polar deposits: Stratigraphy, age, and geodynamical response." Science 320.5880 (2008): 1182-1185. [2] Cutts, James A., and Blake H. Lewis. "Models of climate cycles recorded in Martian polar layered deposits." Icarus 50.2 (1982): 216-244. [3] Plaut J J, Picardi G, Safaeinili A, et al. Subsurface radar sounding of the south polar layered deposits of Mars[J]. science, 2007, 316(5821): 92-95. Acknowledgements: Part of the research leading to these results has received funding from the STFC "MSSL Consolidated Grant" ST/K000977/1 and partial support from the European Union's Seventh Framework Programme (FP7/2007-2013) under iMars grant agreement No. 607379 as well as from the China Scholarship Council and the UCL Dean of MAPS fund.

Detecting and characterizing ice units with the WISDOM Radar

NASA Astrophysics Data System (ADS)

Ciarletti, V.; Plettemeier, D.; Dorizon, S.; Clifford, S. M.; Biancheri-Astier, M.; Dechambre, M.; Saintenoy, A. C.; Costard, F.

2012-12-01

The WISDOM (Water Ice Subsurface Deposit Observation on Mars) Ground Penetrating Radar (GPR) is one of the instruments that have been selected as part of the Pasteur payload of ESA's 2018 ExoMars Rover mission. WISDOM main objectives are to understand the geology and evolution of the landing site and to help identifying locations in the shallow subsurface where organic molecules are the most likely to be found and well-preserved. In the context of the ExoMars mission, the importance of the WISDOM GPR is particularly enhanced by its ability to investigate the distribution and state of subsurface water - both as a liquid and as ice. For example, within the diurnally active thermal layer of the subsurface (i.e., the top ~15 - 25 cm), the transient melting and freezing of subsurface ice and brine may be detectable by comparing day- and night-time radar observations at the same location. Moreover, while the biological significance of liquid water on Mars is obvious, a more readily accessible and enduring record of biological activity may be organic biomarkers preserved in subsurface ice. Unfortunately, the dielectric contrast between rock, soil and ice is small, and therefore, differentiating between mixtures of ice-rich and ice-poor regolith in the Martian subsurface is an extraordinarily difficult task. Preliminary tests in both natural (glacier in the Alps and caves in Austria) and artificial (cold chamber) icy environments have been performed with a prototype representative of the WISDOM instrument flight model. These investigations have demonstrated WISDOM's ability to detect and characterize subsurface ice in various forms. Specific examples will be discussed that demonstrate the instrument's depth of sounding, dielectric sensitivity, spatial resolution, full polarimetric and 3-D capability.

Surveyor V: Television pictures

USGS Publications Warehouse

Shoemaker, E.M.; Batson, R.M.; Holt, H.E.; Morris, E.C.; Rennilson, J.J.; Whitaker, E.A.

1967-01-01

Surveyor V landed in a small crater, 8.5 meters wide and 12.5 meters long, which was probably formed by drainage of surficial fragmental debris into a subsurface fissure. The lunar surface debris layer is exposed in the walls of this crater. At depths below about 10 centimeters, the debris appears to be composed mainly of shock-compressed aggregates, ranging from a few millimeters up to 3 centimeters in diameter, set in a matrix of less-coherent finer particles. Rocky chips and fragments larger than a millimeter are dispersed as a subordinate constituent of the debris.

Mapping soil features from multispectral scanner data

NASA Technical Reports Server (NTRS)

Kristof, S. J.; Zachary, A. L.

1974-01-01

In being able to identify quickly gross variations in soil features, the computer-aided classification of multispectral scanner data can be an effective aid to soil surveying. Variations in soil tone are easily seen as well as variations in features related to soil tone, e.g., drainage patterns and organic matter content. Changes in surface texture also affect the reflectance properties of soils. Inasmuch as conventional soil classes are based on both surface and subsurface soil characteristics, the technique described here can be expected only to augment and not replace traditional soil mapping.

Occurrence, distribution, and transport of pesticides in agricultural irrigation-return flow from four drainage basins in the Columbia Basin Project, Washington, 2002-04, and comparison with historical data

USGS Publications Warehouse

Wagner, Richard J.; Frans, Lonna M.; Huffman, Raegan L.

2006-01-01

Water-quality samples were collected from sites in four irrigation return-flow drainage basins in the Columbia Basin Project from July 2002 through October 2004. Ten samples were collected throughout the irrigation season (generally April through October) and two samples were collected during the non-irrigation season. Samples were analyzed for temperature, pH, specific conductance, dissolved oxygen, major ions, trace elements, nutrients, and a suite of 107 pesticides and pesticide metabolites (pesticide transformation products) and to document the occurrence, distribution, and pesticides transport and pesticide metabolites. The four drainage basins vary in size from 19 to 710 square miles. Percentage of agricultural cropland ranges from about 35 percent in Crab Creek drainage basin to a maximum of 75 percent in Lind Coulee drainage basin. More than 95 percent of cropland in Red Rock Coulee, Crab Creek, and Sand Hollow drainage basins is irrigated, whereas only 30 percent of cropland in Lind Coulee is irrigated. Forty-two pesticides and five metabolites were detected in samples from the four irrigation return-flow drainage basins. The most compounds detected were in samples from Sand Hollow with 37, followed by Lind Coulee with 33, Red Rock Coulee with 30, and Crab Creek with 28. Herbicides were the most frequently detected pesticides, followed by insecticides, metabolites, and fungicides. Atrazine, bentazon, diuron, and 2,4-D were the most frequently detected herbicides and chlorpyrifos and azinphos-methyl were the most frequently detected insecticides. A statistical comparison of pesticide concentrations in surface-water samples collected in the mid-1990s at Crab Creek and Sand Hollow with those collected in this study showed a statistically significant increase in concentrations for diuron and a statistically significant decrease for ethoprophos and atrazine in Crab Creek. Statistically significant increases were in concentrations of bromacil, diuron, and pendimethalin at Sand Hollow and statistically significant decreases were in concentrations of 2,6-diethylanaline, alachlor, atrazine, DCPA, and EPTC. A seasonal Kendall trend test on data from Lind Coulee indicated no statistically significant trends for any pesticide for 1994 through 2004. A comparison of pesticide concentrations detected in this study with those detected in previous U.S. Geological Survey National Water-Quality Assessment studies of the Central Columbia Plateau, Yakima River basin, and national agricultural studies indicated that concentrations in this study generally were in the middle to lower end of the concentration spectrum for the most frequently detected herbicides and insecticides, but that the overall rate of detection was near the high end. Thirty-one of the 42 herbicides, insecticides, and fungicides detected in surface-water samples were applied to the major agricultural crops in the drainage basins, and 11 of the detected pesticides are sold for residential application. Eight of the pesticides detected in surface-water samples were not reported as having any agricultural or residential use. The overall pattern of pesticide use depends on which crops are grown in each drainage basin. Drainage basins with predominantly more orchards have higher amounts of insecticides applied, whereas basins with larger percentages of field crops tend to have more herbicides applied. Pesticide usage was most similar in Crab Creek and Sand Hollow, where the largest total amounts applied were the insecticides azinphos-methyl, carbaryl, and chlorpyrifos and the herbicide EPTC. In Red Rock Coulee basin, DCPA was the most heavily applied herbicide, followed by the fungicide chlorothalonil, the herbicide EPTC, and the insecticides chlorpyrifos and azinphos-methyl. In Lind Coulee, which has a large percentage of dryland agricultural area, the herbicides 2,4-D and EPTC were applied in the largest amount, followed by the fungicide chlorothalonil. The

Lateral and subsurface flows impact arctic coastal plain lake water budgets

USGS Publications Warehouse

Koch, Joshua C.

2016-01-01

Arctic thaw lakes are an important source of water for aquatic ecosystems, wildlife, and humans. Many recent studies have observed changes in Arctic surface waters related to climate warming and permafrost thaw; however, explaining the trends and predicting future responses to warming is difficult without a stronger fundamental understanding of Arctic lake water budgets. By measuring and simulating surface and subsurface hydrologic fluxes, this work quantified the water budgets of three lakes with varying levels of seasonal drainage, and tested the hypothesis that lateral and subsurface flows are a major component of the post-snowmelt water budgets. A water budget focused only on post-snowmelt surface water fluxes (stream discharge, precipitation, and evaporation) could not close the budget for two of three lakes, even when uncertainty in input parameters was rigorously considered using a Monte Carlo approach. The water budgets indicated large, positive residuals, consistent with up to 70% of mid-summer inflows entering lakes from lateral fluxes. Lateral inflows and outflows were simulated based on three processes; supra-permafrost subsurface inflows from basin-edge polygonal ground, and exchange between seasonally drained lakes and their drained margins through runoff and evapotranspiration. Measurements and simulations indicate that rapid subsurface flow through highly conductive flowpaths in the polygonal ground can explain the majority of the inflow. Drained lakes were hydrologically connected to marshy areas on the lake margins, receiving water from runoff following precipitation and losing up to 38% of lake efflux to drained margin evapotranspiration. Lateral fluxes can be a major part of Arctic thaw lake water budgets and a major control on summertime lake water levels. Incorporating these dynamics into models will improve our ability to predict lake volume changes, solute fluxes, and habitat availability in the changing Arctic.

Cenozoic Source-to-Sink of the African margin of the Equatorial Atlantic

NASA Astrophysics Data System (ADS)

Rouby, Delphine; Chardon, Dominique; Huyghe, Damien; Guillocheau, François; Robin, Cecile; Loparev, Artiom; Ye, Jing; Dall'Asta, Massimo; Grimaud, Jean-Louis

2016-04-01

The objective of the Transform Source to Sink Project (TS2P) is to link the dynamics of the erosion of the West African Craton to the offshore sedimentary basins of the African margin of the Equatorial Atlantic at geological time scales. This margin, alternating transform and oblique segments from Guinea to Nigeria, shows a strong structural variability in the margin width, continental geology and relief, drainage networks and subsidence/accumulation patterns. We analyzed this system combining onshore geology and geomorphology as well as offshore sub-surface data. Mapping and regional correlation of dated lateritic paleo-landscape remnants allows us to reconstruct two physiographic configurations of West Africa during the Cenozoic. We corrected those reconstitutions from flexural isostasy related to the subsequent erosion. These geometries show that the present-day drainage organization stabilized by at least 29 Myrs ago (probably by 34 Myr) revealing the antiquity of the Senegambia, Niger and Volta catchments toward the Atlantic as well as of the marginal upwarp currently forming a continental divide. The drainage rearrangement that lead to this drainage organization was primarily enhanced by the topographic growth of the Hoggar swell and caused a major stratigraphic turnover along the Equatorial margin of West Africa. Elevation differences between paleo-landscape remnants give access to the spatial and temporal distribution of denudation for 3 time-increments since 45 Myrs. From this, we estimate the volumes of sediments and associated lithologies exported by the West African Craton toward different segments of the margin, taking into account the type of eroded bedrock and the successive drainage reorganizations. We compare these data to Cenozoic accumulation histories in the basins and discuss their stratigraphic expression according to the type of margin segment they are preserved in.

Using AnnAGNPS to Predict the Effects of Tile Drainage Control on Nutrient and Sediment Loads for a River Basin.

PubMed

Que, Z; Seidou, O; Droste, R L; Wilkes, G; Sunohara, M; Topp, E; Lapen, D R

2015-03-01

Controlled tile drainage (CTD) can reduce pollutant loading. The Annualized Agricultural Nonpoint Source model (AnnAGNPS version 5.2) was used to examine changes in growing season discharge, sediment, nitrogen, and phosphorus loads due to CTD for a ∼3900-km agriculturally dominated river basin in Ontario, Canada. Two tile drain depth scenarios were examined in detail to mimic tile drainage control for flat cropland: 600 mm depth (CTD) and 200 mm (CTD) depth below surface. Summed for five growing seasons (CTD), direct runoff, total N, and dissolved N were reduced by 6.6, 3.5, and 13.7%, respectively. However, five seasons of summed total P, dissolved P, and total suspended solid loads increased as a result of CTD by 0.96, 1.6, and 0.23%. The AnnAGNPS results were compared with mass fluxes observed from paired experimental watersheds (250, 470 ha) in the river basin. The "test" experimental watershed was dominated by CTD and the "reference" watershed by free drainage. Notwithstanding environmental/land use differences between the watersheds and basin, comparisons of seasonal observed and predicted discharge reductions were comparable in 100% of respective cases. Nutrient load comparisons were more consistent for dissolved, relative to particulate water quality endpoints. For one season under corn crop production, AnnAGNPS predicted a 55% decrease (CTD) in dissolved N from the basin. AnnAGNPS v. 5.2 treats P transport from a surface pool perspective, which is appropriate for many systems. However, for assessment of tile drainage management practices for relatively flat tile-dominated systems, AnnAGNPS may benefit from consideration of P and particulate transport in the subsurface. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Selenium and boron in aquatic birds from central California

USGS Publications Warehouse

Paveglio, F.L.; Bunck, C.M.; Heinz, G.H.

1992-01-01

Subsurface agricultural drainwater used for marsh management has resulted in trace element contamination of aquatic bird food chains in central California. Consequently, we collected breeding and wintering aquatic birds from the Grassland Water District (GWD) of California during 1985-88 to measure selenium (Se) and boron (B) contamination resulting from use of such drainage water for wetland management. During the breeding and wintering periods, livers of birds from the North and South areas of the Grasslands contained concentrations of Se and B that have been associated with reproductive impairment. Birds from the South Grasslands, which had received more undiluted drainage water, were more contaminated than those from the North Grasslands. Birds had higher (P < 0.001) levels of Se and B at the end of the 1985-86 wintering period than at the beginning, indicating that the Grasslands was the major source of contamination. Concentrations of Se decreased from 1985 through 1988, after freshwater was substituted for irrigation drainage water during autumn 1985. B concentrations in wintering birds, except for American coots (Fulica americana), declined to background levels, while concentrations in breeding birds remained slightly elevated. However, after 3 years of freshwater management of the Grasslands, liver Se levels in some breeding and wintering birds still were above concentrations associated with impaired reproduction in laboratory and field studies. In areas with high potential for leaching of Se and B from agricultural land, irrigation drainage water should not be used for wetland management.

A STUDY TO DETERMINE THE FEASIBILITY OF USING A GROUND-PENETRATING RADAR FOR MORE EFFECTIVE REMEDIATION OF SUBSURFACE CONTAMINATION

EPA Science Inventory

A study was conducted (1) to assess the capability of groundpenetrating radar (GPR) to identify natural subsurface features, detect man-made objects burled in the soil, and both detect and define the extent of contaminated soil or ground water due to a toxic spill, and (2) to det...

Identification and characterization of natural pipe systems in forested tropical soils

NASA Astrophysics Data System (ADS)

Bovi, Renata Cristina; Moreira, Cesar Augusto; Stucchi Boschi, Raquel; Cooper, Miguel

2017-04-01

Erosive processes on soil surface have been well studied and comprehended by several researchers, however little is known about subsurface erosive processes (piping). Piping is a type of subsurface erosion caused by water flowing in the subsurface and is still considered one of the most difficult erosive processes to be studied. Several processes have been considered as resposible for subsurface erosion and their interaction is complex and difficult to be studied separately. Surface investigations on their own may underestimate the erosion processes, due to the possible occurrence of subsurface processes that are not yet exposed on the surface. The network of subsurface processes should also be understood to better control erosion. Conservation practices that focus on water runoff control may be inefficient if the subsurface flow is not considered. In this study, we aimed to identify and characterize subsurface cavities in the field, as well as understand the network of these cavities, by using geophysical methods (electrical tomography). The study area is situated at the Experimental Station of Tupi, state of São Paulo, Brazil. The soil of the area was classified as Hapludults. The area presents several erosive features, ranging from laminar to permanent gullies and subsurface erosions. The geophysical equipment used was the Terrameter LS resistivity meter, manufactured by ABEM Instruments. The method of electrical tomography was efficient to detect collapsed and non-collapsed pipes. The results presented valuable information to detect areas of risk.

Characterizing the Frequency and Elevation of Rapid Drainage Events in West Greenland

NASA Astrophysics Data System (ADS)

Cooley, S.; Christoffersen, P.

2016-12-01

Rapid drainage of supraglacial lakes on the Greenland Ice Sheet is critical for the establishment of surface-to-bed hydrologic connections and the subsequent transfer of water from surface to bed. Yet, estimates of the number and spatial distribution of rapidly draining lakes vary widely due to limitations in the temporal frequency of image collection and obscureness by cloud. So far, no study has assessed the impact of these observation biases. In this study, we examine the frequency and elevation of rapidly draining lakes in central West Greenland, from 68°N to 72.6°N, and we make a robust statistical analysis to estimate more accurately the likelihood of lakes draining rapidly. Using MODIS imagery and a fully automated lake detection method, we map more than 500 supraglacial lakes per year over a 63000 km2 study area from 2000-2015. Through testing four different definitions of rapidly draining lakes from previously published studies, we find that the number of rapidly draining lakes varies from 3% to 38%. Logistic regression between rapid drainage events and image sampling frequency demonstrates that the number of rapid drainage events is strongly dependent on cloud-free observation percentage. We then develop three new drainage criteria and apply an observation bias correction that suggests a true rapid drainage probability between 36% and 45%, considerably higher than previous studies without bias assessment have reported. We find rapid-draining lakes are on average larger and disappear earlier than slow-draining lakes, and we also observe no elevation differences for the lakes detected as rapidly draining. We conclude a) that methodological problems in rapid drainage research caused by observation bias and varying detection methods have obscured large-scale rapid drainage characteristics and b) that the lack of evidence for an elevation limit on rapid drainage suggests surface-to-bed hydrologic connections may continue to propagate inland as climate warms.

Low frequency acoustic microscope

DOEpatents

Khuri-Yakub, Butrus T.

1986-11-04

A scanning acoustic microscope is disclosed for the detection and location of near surface flaws, inclusions or voids in a solid sample material. A focused beam of acoustic energy is directed at the sample with its focal plane at the subsurface flaw, inclusion or void location. The sample is scanned with the beam. Detected acoustic energy specularly reflected and mode converted at the surface of the sample and acoustic energy reflected by subsurface flaws, inclusions or voids at the focal plane are used for generating an interference signal which is processed and forms a signal indicative of the subsurface flaws, inclusions or voids.

Multiphase flow predictions from carbonate pore space images using extracted network models

NASA Astrophysics Data System (ADS)

Al-Kharusi, Anwar S.; Blunt, Martin J.

2008-06-01

A methodology to extract networks from pore space images is used to make predictions of multiphase transport properties for subsurface carbonate samples. The extraction of the network model is based on the computation of the location and sizes of pores and throats to create a topological representation of the void space of three-dimensional (3-D) rock images, using the concept of maximal balls. In this work, we follow a multistaged workflow. We start with a 2-D thin-section image; convert it statistically into a 3-D representation of the pore space; extract a network model from this image; and finally, simulate primary drainage, waterflooding, and secondary drainage flow processes using a pore-scale simulator. We test this workflow for a reservoir carbonate rock. The network-predicted absolute permeability is similar to the core plug measured value and the value computed on the 3-D void space image using the lattice Boltzmann method. The predicted capillary pressure during primary drainage agrees well with a mercury-air experiment on a core sample, indicating that we have an adequate representation of the rock's pore structure. We adjust the contact angles in the network to match the measured waterflood and secondary drainage capillary pressures. We infer a significant degree of contact angle hysteresis. We then predict relative permeabilities for primary drainage, waterflooding, and secondary drainage that agree well with laboratory measured values. This approach can be used to predict multiphase transport properties when wettability and pore structure vary in a reservoir, where experimental data is scant or missing. There are shortfalls to this approach, however. We compare results from three networks, one of which was derived from a section of the rock containing vugs. Our method fails to predict properties reliably when an unrepresentative image is processed to construct the 3-D network model. This occurs when the image volume is not sufficient to represent the geological variations observed in a core plug sample.

Searching for Life in the Martian Subsurface: Results from the MARTE Astrobiological Drilling Experiment and Implications for Future Missions

NASA Astrophysics Data System (ADS)

Stoker, C. R.

2007-07-01

Drilling for subsurface life should be a goal of future Mars missions. The approach is illustrated by MARTE: A search for subsurface life in Rio Tinto, Spain explored a biosphere using reduced iron and sulfur minerals and demonstrated automated drilling, sample handling, and life detection.

Detection in subsurface air of radioxenon released from medical isotope production

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, Christine; Biegalski, Steven; Haas, Derek

Abstract Under the Comprehensive Nuclear-Test-Ban Treaty, an On-Site Inspection (OSI) may be conducted to clarify whether a nuclear explosion has been carried out in violation of Article I of the Treaty. A major component of an OSI is the measurement of subsurface gases in order to detect radioactive noble gases that are produced in a nuclear explosion, particularly radioxenon and radioargon. In order to better understand potential backgrounds of these gases, a sampling campaign was performed near Canadian Nuclear Laboratories in the Ottawa River Valley, a major source of environmental radioxenon. First of their kind measurements of atmospheric radioxenon imprintedmore » into the shallow subsurface from an atmospheric pressure driven force were made using current OSI techniques to measure both atmospheric and subsurface gas samples which were analyzed for radioxenon. These measurements indicate that under specific sampling conditions, on the order of one percent of the atmospheric radioxenon concentration may be measured via subsurface sampling.« less

A Spatially Offset Raman Spectroscopy Method for Non-Destructive Detection of Gelatin-Encapsulated Powders

PubMed Central

Chao, Kuanglin; Dhakal, Sagar; Qin, Jianwei; Peng, Yankun; Schmidt, Walter F.; Kim, Moon S.; Chan, Diane E.

2017-01-01

Non-destructive subsurface detection of encapsulated, coated, or seal-packaged foods and pharmaceuticals can help prevent distribution and consumption of counterfeit or hazardous products. This study used a Spatially Offset Raman Spectroscopy (SORS) method to detect and identify urea, ibuprofen, and acetaminophen powders contained within one or more (up to eight) layers of gelatin capsules to demonstrate subsurface chemical detection and identification. A 785-nm point-scan Raman spectroscopy system was used to acquire spatially offset Raman spectra for an offset range of 0 to 10 mm from the surfaces of 24 encapsulated samples, using a step size of 0.1 mm to obtain 101 spectral measurements per sample. As the offset distance was increased, the spectral contribution from the subsurface powder gradually outweighed that of the surface capsule layers, allowing for detection of the encapsulated powders. Containing mixed contributions from the powder and capsule, the SORS spectra for each sample were resolved into pure component spectra using self-modeling mixture analysis (SMA) and the corresponding components were identified using spectral information divergence values. As demonstrated here for detecting chemicals contained inside thick capsule layers, this SORS measurement technique coupled with SMA has the potential to be a reliable non-destructive method for subsurface inspection and authentication of foods, health supplements, and pharmaceutical products that are prepared or packaged with semi-transparent materials. PMID:28335453

Inferring changes in water cycle dynamics of intensively managed landscapes via the theory of time-variant travel time distributions

NASA Astrophysics Data System (ADS)

Danesh-Yazdi, Mohammad; Foufoula-Georgiou, Efi; Karwan, Diana L.; Botter, Gianluca

2016-10-01

Climatic trends and anthropogenic changes in land cover and land use are impacting the hydrology and water quality of streams at the field, watershed, and regional scales in complex ways. In poorly drained agricultural landscapes, subsurface drainage systems have been successful in increasing crop productivity by removing excess soil moisture. However, their hydroecological consequences are still debated in view of the observed increased concentrations of nitrate, phosphorus, and pesticides in many streams, as well as altered runoff volumes and timing. In this study, we employ the recently developed theory of time-variant travel time distributions within the StorAge Selection function framework to quantify changes in water cycle dynamics resulting from the combined climate and land use changes. Our results from analysis of a subbasin in the Minnesota River Basin indicate a significant decrease in the mean travel time of water in the shallow subsurface layer during the growing season under current conditions compared to the pre-1970s conditions. We also find highly damped year-to-year fluctuations in the mean travel time, which we attribute to the "homogenization" of the hydrologic response due to artificial drainage. The dependence of the mean travel time on the spatial heterogeneity of some soil characteristics as well as on the basin scale is further explored via numerical experiments. Simulations indicate that the mean travel time is independent of scale for spatial scales larger than approximately 200 km2, suggesting that hydrologic data from larger basins may be used to infer the average of smaller-scale-driven changes in water cycle dynamics.

Inferring tectonic activity using drainage network and RT model: an example from the western Himalayas, India

NASA Astrophysics Data System (ADS)

Sahoo, Ramendra; Jain, Vikrant

2017-04-01

Morphology of the landscape and derived features are regarded to be an important tool for inferring about tectonic activity in an area, since surface exposures of these subsurface processes may not be available or may get eroded away over time. This has led to an extensive research in application of the non-planar morphological attributes like river long profile and hypsometry for tectonic studies, whereas drainage network as a proxy for tectonic activity has not been explored greatly. Though, significant work has been done on drainage network pattern which started in a qualitative manner and over the years, has evolved to incorporate more quantitative aspects, like studying the evolution of a network under the influence of external and internal controls. Random Topology (RT) model is one of these concepts, which elucidates the connection between evolution of a drainage network pattern and the entropy of the drainage system and it states that in absence of any geological controls, a natural population of channel networks will be topologically random. We have used the entropy maximization principle to provide a theoretical structure for the RT model. Furthermore, analysis was carried out on the drainage network structures around Jwalamukhi thrust in the Kangra reentrant in western Himalayas, India, to investigate the tectonic activity in the region. Around one thousand networks were extracted from the foot-wall (fw) and hanging-wall (hw) region of the thrust sheet and later categorized based on their magnitudes. We have adopted the goodness of fit test for comparing the network patterns in fw and hw drainage with those derived using the RT model. The null hypothesis for the test was, the drainage networks in the fw are statistically more similar than those on the hw, to the network patterns derived using the RT model for any given magnitude. The test results are favorable to our null hypothesis for networks with smaller magnitudes (< 9), whereas for larger magnitudes, both hw and fw networks were found to be statistically not similar to the model network patterns. Calculation of pattern frequency for each magnitude and subsequent hypothesis testing were carried out using Matlab (v R2015a). Our results will help to define drainage network pattern as one of the geomorphic proxy to identify tectonically active area. This study also serve as a supplementary proof of the neo-tectonic control on the morphology of landscape and its derivatives around the Jwalamukhi thrust. Additionally, it will help to verify the theory of probabilistic evolution of drainage networks.

Force measurement-based discontinuity detection during friction stir welding

DOE PAGES

Shrivastava, Amber; Zinn, Michael; Duffie, Neil A.; ...

2017-02-23

Here, the objective of this work is to develop a method for detecting the creation of discontinuities ( i.e., voids, volume defects) during friction stir welding. Friction stir welding is inherently cost effective, however, the need for significant weld inspection can make the process cost prohibitive. A new approach to weld inspection is required in which an in situ characterization of weld quality can be obtained, reducing the need for postprocess inspection. To this end, friction stir welds with subsurface voids and without voids were created. The subsurface voids were generated by reducing the friction stir tool rotation frequency andmore » increasing the tool traverse speed in order to create “colder” welds. Process forces were measured during welding, and the void sizes were measured postprocess by computerized tomography ( i.e., 3D X-ray imaging). Two parameters, based on frequency domain content and time-domain average of the force signals, were found to be correlated with void size. Criteria for subsurface void detection and size prediction were developed and shown to be in good agreement with experimental observations. Furthermore, with the proper choice of data acquisition system and frequency analyzer the occurrence of subsurface voids can be detected in real time.« less

Force measurement-based discontinuity detection during friction stir welding

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shrivastava, Amber; Zinn, Michael; Duffie, Neil A.

Here, the objective of this work is to develop a method for detecting the creation of discontinuities ( i.e., voids, volume defects) during friction stir welding. Friction stir welding is inherently cost effective, however, the need for significant weld inspection can make the process cost prohibitive. A new approach to weld inspection is required in which an in situ characterization of weld quality can be obtained, reducing the need for postprocess inspection. To this end, friction stir welds with subsurface voids and without voids were created. The subsurface voids were generated by reducing the friction stir tool rotation frequency andmore » increasing the tool traverse speed in order to create “colder” welds. Process forces were measured during welding, and the void sizes were measured postprocess by computerized tomography ( i.e., 3D X-ray imaging). Two parameters, based on frequency domain content and time-domain average of the force signals, were found to be correlated with void size. Criteria for subsurface void detection and size prediction were developed and shown to be in good agreement with experimental observations. Furthermore, with the proper choice of data acquisition system and frequency analyzer the occurrence of subsurface voids can be detected in real time.« less

Application of electromagnetic techniques in survey of contaminated groundwater at an abandoned mine complex in southwestern Indiana, U.S.A.

USGS Publications Warehouse

Brooks, G.A.; Olyphant, G.A.; Harper, D.

1991-01-01

In part of a large abandoned mining complex, electromagnetic geophysical surveys were used along with data derived from cores and monitoring wells to infer sources of contamination and subsurface hydrologic connections between acidic refuse deposits and adjacent undisturbed geologic materials. Electrical resistivity increases sharply along the boundary of an elevated deposit of pyritic coarse refuse, which is highly contaminated and electrically conductive, indicating poor subsurface hydrologic connections with surrounding deposits of fine refuse and undisturbed glacial material. Groundwater chemistry, as reflected in values of specific conductance, also differs markedly across the deposit's boundary, indicating that a widespread contaminant plume has not developed around the coarse refuse in more than 40 yr since the deposit was created. Most acidic drainage from the coarse refuse is by surface runoff and is concentrated around stream channels. Although most of the contaminated groundwater within the study area is concentrated within the surficial refuse deposits, transects of apparent resistivity and phase angle indicate the existence of an anomalous conductive layer at depth (>4 m) in thick alluvial sediments along the northern boundary of the mining complex. Based on knowledge of local geology, the anomaly is interpreted to represent a subsurface connection between the alluvium and a flooded abandoned underground mine. ?? 1991 Springer-Verlag New York Inc.

Application of electromagnetic techniques in survey of contaminated groundwater at an abandoned mine complex in southwestern Indiana, U.S.A.

NASA Astrophysics Data System (ADS)

Brooks, Glenn A.; Olyphant, Greg A.; Harper, Denver

1991-07-01

In part of a large abandoned mining complex, electromagnetic geophysical surveys were used along with data derived from cores and monitoring wells to infer sources of contamination and subsurface hydrologic connections between acidic refuse deposits and adjacent undisturbed geologic materials. Electrical resistivity increases sharply along the boundary of an elevated deposit of pyritic coarse refuse, which is highly contaminated and electrically conductive, indicating poor subsurface hydrologic connections with surrounding deposits of fine refuse and undisturbed glacial material. Groundwater chemistry, as reflected in values of specific conductance, also differs markedly across the deposit's boundary, indicating that a widespread contaminant plume has not developed around the coarse refuse in more than 40 yr since the deposit was created. Most acidic drainage from the coarse refuse is by surface runoff and is concentrated around stream channels. Although most of the contaminated groundwater within the study area is concentrated within the surficial refuse deposits, transects of apparent resistivity and phase angle indicate the existence of an anomalous conductive layer at depth (>4 m) in thick alluvial sediments along the northern boundary of the mining complex. Based on knowledge of local geology, the anomaly is interpreted to represent a subsurface connection between the alluvium and a flooded abandoned underground mine.

The role of subsurface water flow paths on hillslope hydrological processes, landslides and landform development in steep mountains of Japan

NASA Astrophysics Data System (ADS)

Onda, Yuichi; Tsujimura, Maki; Tabuchi, Hidekazu

2004-03-01

Hydrological monitoring was conducted in high-relief watersheds in the Japan Alps to investigate the relationship between hillslope hydrological processes and landform evolution in steep granite and shale mountains. In the Koshibu watershed, underlain by Mesozoic shale, the drainage density and frequency was significantly lower than in the Yotagiri watershed underlain by granite. Drainage micro-morphology analysis showed that hillslopes in the watersheds K1 and K6 (Koshibu basin) are mostly combinations of talus and bedrock exposures. In contrast, watershed Y1 (Yotagiri basin) is composed of several zero-order streams with hollows. Infinite slope stability analysis indicates that the regolith shear strength in the K6 watershed (Koshibu basin) is lower than that of the Y1 hillslope, but groundwater levels were higher in the Y1 hillslope than in the K6 hillslope during storm events. These data suggest that, although the shear strength of the soil is stronger in the Yotagiri watershed, the slopes are unstable because of the groundwater conditions, whereas deep-seated landslides may occur episodically in the Koshibu watershed associated with extreme storms and very high antecedent soil moisture. These differences would strongly contribute to the different observed hillslope processes and drainage characteristics.

Controls on streamflow intermittence in the Colorado Front Range

NASA Astrophysics Data System (ADS)

Kampf, S. K.; Puntenney, K.; Martin, C.; Weber, R.; Gerlich, J.; Hammond, J. C.; Lefsky, M. A.

2017-12-01

Intermittent streams comprise more than 60% of the channel length in semiarid northern Colorado, yet little is known about their flow magnitude and timing. We used field surveys, stream sensors, and remote sensing to quantify spatial and temporal patterns of streamflow intermittence in the Cache la Poudre basin in 2016-2017. To evaluate potential controls on streamflow intermittence, we delineated the drainage area to each monitored point and quantified the catchment's mean precipitation, temperature, snow persistence, slope, aspect, vegetation type, soil type, and bedrock geology. During the period of study, most streams below 2500 m elevation and <550 mm mean annual precipitation were intermittent, with flow only during the early spring and summer. In these drier low elevation areas, flow duration generally increased with precipitation and snow persistence. Locally, the type of bedrock geology and location of streams relative to faults affected flow duration. Above 2500 m, nearly all streams with drainage areas >1 km2 had perennial flow, whereas nearly all streams with drainage areas <1 km2 had intermittent flow. For the high elevation intermittent streams, stream locations often differed substantially from the locations mapped in standard GIS data products. Initial analyses have identified no clearly quantifiable controls on flow duration of high elevation streams, but field observations indicate subsurface flow paths are important contributors to surface streams.

Capillary pressure heterogeneity and hysteresis for the supercritical CO2/water system in a sandstone

NASA Astrophysics Data System (ADS)

Pini, Ronny; Benson, Sally M.

2017-10-01

We report results from an experimental investigation on the hysteretic behaviour of the capillary pressure curve for the supercritical CO2-water system in a Berea Sandstone core. Previous observations have highlighted the importance of subcore-scale capillary heterogeneity in developing local saturations during drainage; we show in this study that the same is true for the imbibition process. Spatially distributed drainage and imbibition scanning curves were obtained for mm-scale subsets of the rock sample non-invasively using X-ray CT imagery. Core- and subcore-scale measurements are well described using the Brooks-Corey formalism, which uses a linear trapping model to compute mobile saturations during imbibition. Capillary scaling yields two separate universal drainage and imbibition curves that are representative of the full subcore-scale data set. This enables accurate parameterisation of rock properties at the subcore-scale in terms of capillary scaling factors and permeability, which in turn serve as effective indicators of heterogeneity at the same scale even when hysteresis is a factor. As such, the proposed core-analysis workflow is quite general and provides the required information to populate numerical models that can be used to extend core-flooding experiments to conditions prevalent in the subsurface, which would be otherwise not attainable in the laboratory.

Linking selenium sources to ecosystems: San Francisco Bay-Delta Model

USGS Publications Warehouse

Presser, Theresa S.; Luoma, Samuel N.

2004-01-01

Marine sedimentary rocks of the Coast Ranges contribute selenium to soil, surface water, and ground water in the western San Joaquin Valley, California. Irrigation funnels selenium into a network of subsurface drains and canals. Proposals to build a master drain (i.e., San Luis Drain) to discharge into the San Francisco Bay-Delta Estuary remain as controversial today as they were in the 1950s, when drainage outside the San Joaquin Valley was first considered. An existing 85-mile portion of the San Luis Drain was closed in 1986 after fish mortality and deformities in ducks, grebes and coots were discovered at Kesterson National Wildlife Refuge, the temporary terminus of the drain. A 28-mile portion of the drain now conveys drainage from 100,000 acres into the San Joaquin River and eventually into the Bay-Delta. If the San Luis Drain is extended directly to the Bay-Delta, as is now being proposed as an alternative to sustain agriculture, it could receive drainage from an estimated one-million acres of farmland affected by rising water tables and increasing salinity. In addition to agricultural sources, oil refineries also discharge selenium to the Bay-Delta, although those discharges have declined in recent years. To understand the effects of changing selenium inputs, scientists have developed the Bay-Delta Selenium Model.

Non-invasive flow path characterization in a mining-impacted wetland

USGS Publications Warehouse

Bethune, James; Randell, Jackie; Runkel, Robert L.; Singha, Kamini

2015-01-01

Time-lapse electrical resistivity (ER) was used to capture the dilution of a seasonal pulse of acid mine drainage (AMD) contamination in the subsurface of a wetland downgradient of the abandoned Pennsylvania mine workings in central Colorado. Data were collected monthly from mid-July to late October of 2013, with an additional dataset collected in June of 2014. Inversion of the ER data shows the development through time of multiple resistive anomalies in the subsurface, which corroborating data suggest are driven by changes in total dissolved solids (TDS) localized in preferential flow pathways. Sensitivity analyses on a synthetic model of the site suggest that the anomalies would need to be at least several meters in diameter to be adequately resolved by the inversions. The existence of preferential flow paths would have a critical impact on the extent of attenuation mechanisms at the site, and their further characterization could be used to parameterize reactive transport models in developing quantitative predictions of remediation strategies.

Water-quality characteristics in runoff for three discovery farms in North Dakota, 2008-12

USGS Publications Warehouse

Nustad, Rochelle A.; Rowland, Kathleen M.; Wiederholt, Ronald

2015-01-01

Consistent patterns in water quality emerged at each individual farm, but similarities among farms also were observed. Suspended sediment, total phosphorus, and ammonia concentrations generally decreased downstream from feeding areas, and were primarily affected by surface runoff processes such as dilution, settling out of sediment, or vegetative uptake. Because surface runoff affects these constituents, increased annual surface runoff volume tended to result in increased loads and yields. No significant change in nitrate plus nitrite concentration were observed downstream from feeding areas because additional processes such as high solubility, nitrification, denitrification, and surface-groundwater interaction affect nitrate plus nitrite. For nitrate plus nitrite, increases in annual runoff volume did not consistently relate to increases in annual loads and yields. It seems that temporal distribution of precipitation and surface-groundwater interaction affected nitrate plus nitrite loads and yields. For surface drainage sites, the primary form of nitrogen was organic nitrogen whereas for subsurface drainage sites, the primary form of nitrogen was nitrate plus nitrite nitrogen.

Planetary science and exploration in the deep subsurface: results from the MINAR Program, Boulby Mine, UK

NASA Astrophysics Data System (ADS)

Payler, Samuel J.; Biddle, Jennifer F.; Coates, Andrew J.; Cousins, Claire R.; Cross, Rachel E.; Cullen, David C.; Downs, Michael T.; Direito, Susana O. L.; Edwards, Thomas; Gray, Amber L.; Genis, Jac; Gunn, Matthew; Hansford, Graeme M.; Harkness, Patrick; Holt, John; Josset, Jean-Luc; Li, Xuan; Lees, David S.; Lim, Darlene S. S.; McHugh, Melissa; McLuckie, David; Meehan, Emma; Paling, Sean M.; Souchon, Audrey; Yeoman, Louise; Cockell, Charles S.

2017-04-01

The subsurface exploration of other planetary bodies can be used to unravel their geological history and assess their habitability. On Mars in particular, present-day habitable conditions may be restricted to the subsurface. Using a deep subsurface mine, we carried out a program of extraterrestrial analog research - MINe Analog Research (MINAR). MINAR aims to carry out the scientific study of the deep subsurface and test instrumentation designed for planetary surface exploration by investigating deep subsurface geology, whilst establishing the potential this technology has to be transferred into the mining industry. An integrated multi-instrument suite was used to investigate samples of representative evaporite minerals from a subsurface Permian evaporite sequence, in particular to assess mineral and elemental variations which provide small-scale regions of enhanced habitability. The instruments used were the Panoramic Camera emulator, Close-Up Imager, Raman spectrometer, Small Planetary Linear Impulse Tool, Ultrasonic drill and handheld X-ray diffraction (XRD). We present science results from the analog research and show that these instruments can be used to investigate in situ the geological context and mineralogical variations of a deep subsurface environment, and thus habitability, from millimetre to metre scales. We also show that these instruments are complementary. For example, the identification of primary evaporite minerals such as NaCl and KCl, which are difficult to detect by portable Raman spectrometers, can be accomplished with XRD. By contrast, Raman is highly effective at locating and detecting mineral inclusions in primary evaporite minerals. MINAR demonstrates the effective use of a deep subsurface environment for planetary instrument development, understanding the habitability of extreme deep subsurface environments on Earth and other planetary bodies, and advancing the use of space technology in economic mining.

Tile Drainage Expansion Detection using Satellite Soil Moisture Dynamics

NASA Astrophysics Data System (ADS)

Jacobs, J. M.; Cho, E.; Jia, X.

2017-12-01

In the past two decades, tile drainage installation has accelerated throughout the Red River of the North Basin (RRB) in parts of western Minnesota, eastern North Dakota, and a small area of northeastern South Dakota, because the flat topography and low-permeability soils in this region necessitated the removal of excess water to improve crop production. Interestingly, streamflow in the Red River has markedly increased and six of 13 major floods during the past century have occurred since the late 1990s. It has been suggested that the increase in RRB flooding could be due to change in agricultural practices, including extensive tile drainage installation. Reliable information on existing and future tile drainage installation is greatly needed to capture the rapid extension of tile drainage systems and to locate tile drainage systems in the north central U.S. including the RRB region. However, there are few reliable data of tile drainage installation records, except tile drainage permit records in the Bois de Sioux watershed (a sub-basin in southern part of the RRB where permits are required for tile drainage installation). This study presents a tile drainage expansion detection method based on a physical principle that the soil-drying rate may increase with increasing tile drainage for a given area. In order to capture the rate of change in soil drying rate with time over entire RRB (101,500 km2), two satellite-based microwave soil moisture records from the Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E) and AMSR2 were used during 2002 to 2016. In this study, a sub-watershed level (HUC10) potential tile drainage growth map was developed and the results show good agreement with tile drainage permit records of six sub-watersheds in the Bois de Sioux watershed. Future analyses will include improvement of the potential tile drainage map through additional information using optical- and thermal-based sensor products and evaluation of its hydrological impacts on intensity, duration, and frequency of extreme streamflow from watershed to basin scale.

Peatland Structural Controls on Spring Distribution

NASA Astrophysics Data System (ADS)

Hare, D. K.; Boutt, D. F.; Hackman, A. M.; Davenport, G.

2013-12-01

The species richness of wetland ecosystems' are sustained by the presence of discrete groundwater discharge, or springs. Springs provide thermal refugia and a source of fresh water inflow crucial for survival of many wetland species. The subsurface drivers that control the spatial distribution of surficial springs throughout peatland complexes are poorly understood due to the many challenges peatlands pose for hydrologic characterization, such as the internal heterogeneities, soft, dynamic substrate, and low gradient of peat drainage. This has previously made it difficult to collect spatial data required for restoration projects that seek to support spring obligate and thermally stressed species such as trout. Tidmarsh Farms is a 577-acre site in Southeastern Massachusetts where 100+ years of cranberry farming has significantly altered the original peatland hydrodynamics and ecology. Farming practices such as the regular application of sand, straightening of the main channel, and addition of drainage ditches has strongly degraded this peatland ecosystem. Our research has overlain non-invasive geophysical, thermal, and water isotopic data from the Tidmarsh Farms peatland to provide a detailed visualization of how subsurface peat structure and spring patterns correlate. Ground penetrating radar (GPR) has proven particularly useful in characterizing internal peat structure and the mineral soil interface beneath peatlands, we interpolate the peatland basin at a large scale (1 km2) and compare this 3-D surface to the locations of springs on the peat platform. Springs, expressed as cold anomalies in summer and warm anomalies in winter, were specifically located by combining fiber-optic and infrared thermal surveys, utilizing the numerous relic agricultural drainage ditches as a sampling advantage. Isotopic signatures of the spring locations are used to distinguish local and regional discharge, differences that can be explained in part by the peat basin structure delineated with GPR. The study expands our understanding of complex peat systems and will be used to inform wetland restoration based on hydrodynamic processes; yielding a more successful, resilient restoration and desired ecologic function. Our research demonstrates how the use of GPR in combination with thermal imagery and isotopic analysis can help characterize degraded peatlands, informing a process-based approach to ecological restoration of the site with the ability to monitor changes through time.

In situ high temperature microwave microscope for nondestructive detection of surface and sub-surface defects.

PubMed

Wang, Peiyu; Li, Zhencheng; Pei, Yongmao

2018-04-16

An in situ high temperature microwave microscope was built for detecting surface and sub-subsurface structures and defects. This system was heated with a self-designed quartz lamp radiation module, which is capable of heating to 800°C. A line scanning of a metal grating showed a super resolution of 0.5 mm (λ/600) at 1 GHz. In situ scanning detections of surface hole defects on an aluminium plate and a glass fiber reinforced plastic (GFRP) plate were conducted at different high temperatures. A post processing algorithm was proposed to remove the background noises induced by high temperatures and the 3.0 mm-spaced hole defects were clearly resolved. Besides, hexagonal honeycomb lattices were in situ detected and clearly resolved under a 1.0 mm-thick face panel at 20°C and 50°C, respectively. The core wall positions and bonding width were accurately detected and evaluated. In summary, this in situ microwave microscope is feasible and effective in sub-surface detection and super resolution imaging at different high temperatures.

Geophysical Investigations at Hidden Dam, Raymond, California: Summary of Fieldwork and Data Analysis

USGS Publications Warehouse

Minsley, Burke J.; Burton, Bethany L.; Ikard, Scott; Powers, Michael H.

2010-01-01

Geophysical field investigations have been carried out at the Hidden Dam in Raymond, California for the purpose of better understanding the hydrogeology and seepage-related conditions at the site. Known seepage areas on the northwest right abutment area of the downstream side of the dam are documented by Cedergren. Subsequent to the 1980 seepage study, a drainage blanket with a subdrain system was installed to mitigate downstream seepage. Flow net analysis provided by Cedergren suggests that the primary seepage mechanism involves flow through the dam foundation due to normal reservoir pool elevations, which results in upflow that intersects the ground surface in several areas on the downstream side of the dam. In addition to the reservoir pool elevations and downstream surface topography, flow is also controlled by the existing foundation geology as well as the presence or absence of a horizontal drain within the downstream portion of the dam. The purpose of the current geophysical work is to (1) identify present-day seepage areas that may not be evident due to the effectiveness of the drainage blanket in redirecting seepage water, and (2) provide information about subsurface geologic structures that may control subsurface flow and seepage. These tasks are accomplished through the use of two complementary electrical geophysical methods, self-potentials (SP) and direct-current (DC) electrical resistivity, which have been commonly utilized in dam-seepage studies. SP is a passive method that is primarily sensitive to active subsurface groundwater flow and seepage, whereas DC resistivity is an active-source method that is sensitive to changes in subsurface lithology and groundwater saturation. The focus of this field campaign was on the downstream area on the right abutment, or northwest side of the dam, as this is the main area of interest regarding seepage. Two exploratory self-potential lines were also collected on the downstream left abutment of the dam to identify potential seepage in that area. This report is primarily a summary of the field geophysical data acquisition, with some preliminary results and interpretation. Further work will involve a more rigorous analysis of the geophysical datasets and an examination of a large dataset of historical observations of water levels in a number of observation wells and piezometers compared with reservoir elevation. In addition, a partially saturated flow model will be developed to better understand seepage patterns given the available information about dam construction, geophysical results, and data from installed observation wells and piezometers.

Potential influence of sugarcane cultivation on estuarine water quality of Louisiana's gulf coast.

PubMed

Southwick, Lloyd M; Grigg, Brandon C; Kornecki, Ted S; Fouss, James L

2002-07-17

Sugarcane is cultivated on some 170000 ha of land in south central and southwestern Louisiana. This acreage drains into bayous and rivers that empty into Louisiana's coastal bays and estuaries. For a number of years the state's Department of Agriculture and Forestry and Department of Environmental Quality have collected water quality data from this sugarcane area. Study of these data shows that approximately one in five detections of atrazine is above the maximum contaminant level (MCL) for drinking water. Currently there is no U.S. atrazine standard for protection of aquatic life. February and October detections of this herbicide are probably due to sugarcane cultivation. Nitrate levels have remained below the MCL for drinking water, but nitrate and phosphorus concentrations may pose a potential for eutrophication problems. The contribution of sugarcane production to the nutrient status of Louisiana's coastal water bodies is difficult to assess because there are other sources of nutrients in the area and native soil phosphorus levels are high. Cultural practices such as subsurface drains, open drainage ditches, and postharvest residue management have potential through enhancement of soil infiltration for decreasing sugarcane's contribution to water quality problems in southern and coastal Louisiana. A new field project is being installed at the Louisiana State University Agricultural Experiment Station's Sugarcane Research Station at St. Gabriel to assess the water quality benefits of these practices with respect to sugarcane cultivation.

Diuretic 99mTc DTPA renography in assessment of renal function and drainage in infants with antenatally detected hydronephrosis.

PubMed

Radulović, Marija; Pucar, Dragan; Jauković, Ljiljana; Sisić, Marija; Krstić, Zoran; Ajdinović, Boris

2015-12-01

The controversy over the postnatal management of infants with antenataly detected hydronephrosis (ANH) still exists. We presented the results of diuretic 99mTc diethylenetriamine pentaacetic acid (DTPA) renography in 30 infants with the antenatal diagnosis of unilateral renal pelvic dilatation. The aim of this study was to assess the renal function determined by the pattern of drainage and split renal function (SRF) on diuretic renography and to correlate these findings with anteroposterior pelvic diameter (APD) estimated by ultrasonography. A total of 30 infants with 60 renal units (RU) (25 boys and 5 girls, median age 6.0 months, range 2-24) presented with unilateral hydronephrosis on ultrasound in the newborn period, underwent DTPA diuretic renal scintigraphy (F+15 protocol). The median APD evaluated on perinatal ultrasound was 15 mm (range 5-30). The postnatal associated clinical diagnosis were pelviureteric junction obstruction (PUJ), simple hydronephrosis, megaureter, vesicoureteral reflux (VUR) and posterior urethral valves in 11, 10, 6, 2 and 1 infant, respectively. Images and Tmax/2 after diuretic stimulation on the background subtracted renographic curves were used as the criteria for classifying the drainage as good, partial, and poor or no drainage. The SRF was calculated with the integral method. Good drainage was shown in 36/60, partial drainage in 13/60 and poor or no drainage in 11/60 RU. The SRF > 40% was observed in 55/60 RU, with no RU showing SRF lower than 23.5%. In infants with severe ANH the obstruction was not excluded in 94.1%. Diuretic renography in antenatally detected hydronephrosis should be a useful tool in postnatal follow up, especially in differentiating nonobstructive hydronephrosis from obstructive. It is also importanat to assess and monitor the SRF. Our results suggest that even in the presence of partial or no drainage, SRF may not be significantly impaired.

Hydro-chemical detection of permafrost degradation in the Eastern European Alps - Implications for geomorphological process studies and natural hazard assessment

NASA Astrophysics Data System (ADS)

Kraushaar, Sabine; Kamleitner, Sarah; Czarnowsky, Verena; Blöthe, Jan; Morche, David; Knöller, Kay; Lachner, Johannes

2017-04-01

The Gepatschferner glacier in the Upper Kaunertal valley is one of the fastest melting glaciers in the Eastern European Alps. With a retreat rate of around 110 m a-1 since the hydrological year 2012/ 2013, unconsolidated sediments of steep lateral moraines have been exposed to erosion, from which nowadays episodic and perennial springs well. We hypothesize that the springs indicate the melt out of dead ice lenses in areas below 2500 m, causing a potential significant morphological change in the moraines and a decrease of slope stability in the proglacial long after glacier retreat. However, permafrost degradation has not been considered so far in contemporary erosion measurements. The present study aims to identify the spring water's origin and displays first attempts of quantifying thermal erosion, which describes the matrix volume loss due to melting and drainage of ice water. Samples were routinely analyzed for temperature, electrical conductivity, δ2H, and δ18O. Results support the hypothesis that certain springs derive from melting ice of similar isotopic signature as the glacier. In a second step, chosen samples were examined for the long-lived anthropogenic nuclide 129I. Since the 1950s the atmospheric abundance of 129I has significantly increased. Its occurrence in the water samples hints a surface contact of the waters in the last 65 years. Springs of ice origin show little 129I content and are believed to derive from dead ice by the glacier. First electric resistivity measurements support the hydro-chemical results and suggest the existence of ice lenses in the subsurface. Ice ablation and discharge measurements allowed first estimates of the thermal erosion volume caused by the melt out and drainage of ice lenses.

Leachate plume delineation and lithologic profiling using surface resistivity in an open municipal solid waste dumpsite, Sri Lanka.

PubMed

Wijesekara, Hasintha Rangana; De Silva, Sunethra Nalin; Wijesundara, Dharani Thanuja De Silva; Basnayake, Bendict Francis Antony; Vithanage, Meththika Suharshini

2015-01-01

This study presents the use of direct current resistivity techniques (DCRT) for investigation and characterization of leachate-contaminated subsurface environment of an open solid waste dumpsite at Kandy, Sri Lanka. The particular dumpsite has no liner and hence the leachate flows directly to the nearby river via subsurface and surface channels. For the identification of possible subsurface flow paths and the direction of the leachate, DCRT (two-dimensional, three-dimensional and vertical electrical sounding) have been applied. In addition, the physico-chemical parameters such as pH, electrical conductivity (EC), alkalinity, hardness, chloride, chemical oxygen demand (COD) and total organic carbon (TOC) of leachate collected from different points of the solid waste dumping area and leachate drainage channel were analysed. Resistivity data confirmed that the leachate flow is confined to the near surface and no separate plume is observed in the downstream area, which may be due to the contamination distribution in the shallow overburden thickness. The stratigraphy with leachate pockets and leachate plume movements was well demarcated inside the dumpsite via low resistivity zones (1-3 Ωm). The recorded EC, alkalinity, hardness and chloride contents in leachate were averaged as 14.13 mS cm⁻¹, 3236, 2241 and 320 mg L⁻¹, respectively, which confirmed the possible causes for low resistivity values. This study confirms that DCRT can be effectively utilized to assess the subsurface characteristics of the open dumpsites to decide on corridor placement and depth of permeable reactive barriers to reduce the groundwater contamination.

Terrestrial and Aerial Ground-Penetrating Radar in Use for the Architectural Researches: Ancient 16TH Century Water Supply and Drainage at the Monastery of EL Escorial (madrid, Spain)

NASA Astrophysics Data System (ADS)

Chias, P.; Abad, T.; Echeverria, E.

2013-07-01

Remote sensing techniques in Archaeology are increasingly essential components of the methodologies used in archaeological and architectural researches. They allow uncovering unique forgotten data which are unobtainable using traditional excavation techniques, mainly because their precise location is lost. These data are still important since they can help to prevent flood effects inside the ancient building cellars and basements, as it happened periodically in El Escorial. Wide ancient drainage galleries run more than one hundred feet downhill outside the building, ensuring that rainwater and springs were adequately drained. Nowadays their plans are lost, and the lack of documents related both to the ancient water supply and drainage systems become an impediment to solve the stains of damp on the stone masonry walls and vaults, and even other occasional flooding effects. In this case, nondestructive techniques were needed to find the ancient underground passages in order to preserve the integrity of the building and its current activities. At a first stage oblique aerial infrared images taken from a helium barrage balloon helped to find easily, quickly and cheaply the buried masonry structures. Secondly, radar pulses were particularly interesting to image the subsurface as they were valuable means of assessing the presence and amount of both soil water and buried structures. The combination of both techniques proved to be an accurate and low-cost way to find the ancient drainage systems. Finally, results were produced by means of open source software.

HESS Opinions: Linking Darcy's equation to the linear reservoir

NASA Astrophysics Data System (ADS)

Savenije, Hubert H. G.

2018-03-01

In groundwater hydrology, two simple linear equations exist describing the relation between groundwater flow and the gradient driving it: Darcy's equation and the linear reservoir. Both equations are empirical and straightforward, but work at different scales: Darcy's equation at the laboratory scale and the linear reservoir at the watershed scale. Although at first sight they appear similar, it is not trivial to upscale Darcy's equation to the watershed scale without detailed knowledge of the structure or shape of the underlying aquifers. This paper shows that these two equations, combined by the water balance, are indeed identical provided there is equal resistance in space for water entering the subsurface network. This implies that groundwater systems make use of an efficient drainage network, a mostly invisible pattern that has evolved over geological timescales. This drainage network provides equally distributed resistance for water to access the system, connecting the active groundwater body to the stream, much like a leaf is organized to provide all stomata access to moisture at equal resistance. As a result, the timescale of the linear reservoir appears to be inversely proportional to Darcy's conductance, the proportionality being the product of the porosity and the resistance to entering the drainage network. The main question remaining is which physical law lies behind pattern formation in groundwater systems, evolving in a way that resistance to drainage is constant in space. But that is a fundamental question that is equally relevant for understanding the hydraulic properties of leaf veins in plants or of blood veins in animals.

Comparison of Contaminant Transport in Agricultural Drainage Water and Urban Stormwater Runoff

PubMed Central

Ranaivoson, Andry Z.; Feyereisen, Gary W.; Rosen, Carl J.; Moncrief, John F.

2016-01-01

Transport of nitrogen and phosphorus from agricultural and urban landscapes to surface water bodies can cause adverse environmental impacts. The main objective of this long-term study was to quantify and compare contaminant transport in agricultural drainage water and urban stormwater runoff. We measured flow rate and contaminant concentration in stormwater runoff from Willmar, Minnesota, USA, and in drainage water from subsurface-drained fields with surface inlets, namely, Unfertilized and Fertilized Fields. Commercial fertilizer and turkey litter manure were applied to the Fertilized Field based on agronomic requirements. Results showed that the City Stormwater transported significantly higher loads per unit area of ammonium, total suspended solids (TSS), and total phosphorus (TP) than the Fertilized Field, but nitrate load was significantly lower. Nitrate load transport in drainage water from the Unfertilized Field was 58% of that from the Fertilized Field. Linear regression analysis indicated that a 1% increase in flow depth resulted in a 1.05% increase of TSS load from the City Stormwater, a 1.07% increase in nitrate load from the Fertilized Field, and a 1.11% increase in TP load from the Fertilized Field. This indicates an increase in concentration with a rise in flow depth, revealing that concentration variation was a significant factor influencing the dynamics of load transport. Further regression analysis showed the importance of targeting high flows to reduce contaminant transport. In conclusion, for watersheds similar to this one, management practices should be directed to load reduction of ammonium and TSS from urban areas, and nitrate from cropland while TP should be a target for both. PMID:27930684

Comparison of Contaminant Transport in Agricultural Drainage Water and Urban Stormwater Runoff.

PubMed

Ghane, Ehsan; Ranaivoson, Andry Z; Feyereisen, Gary W; Rosen, Carl J; Moncrief, John F

2016-01-01

Transport of nitrogen and phosphorus from agricultural and urban landscapes to surface water bodies can cause adverse environmental impacts. The main objective of this long-term study was to quantify and compare contaminant transport in agricultural drainage water and urban stormwater runoff. We measured flow rate and contaminant concentration in stormwater runoff from Willmar, Minnesota, USA, and in drainage water from subsurface-drained fields with surface inlets, namely, Unfertilized and Fertilized Fields. Commercial fertilizer and turkey litter manure were applied to the Fertilized Field based on agronomic requirements. Results showed that the City Stormwater transported significantly higher loads per unit area of ammonium, total suspended solids (TSS), and total phosphorus (TP) than the Fertilized Field, but nitrate load was significantly lower. Nitrate load transport in drainage water from the Unfertilized Field was 58% of that from the Fertilized Field. Linear regression analysis indicated that a 1% increase in flow depth resulted in a 1.05% increase of TSS load from the City Stormwater, a 1.07% increase in nitrate load from the Fertilized Field, and a 1.11% increase in TP load from the Fertilized Field. This indicates an increase in concentration with a rise in flow depth, revealing that concentration variation was a significant factor influencing the dynamics of load transport. Further regression analysis showed the importance of targeting high flows to reduce contaminant transport. In conclusion, for watersheds similar to this one, management practices should be directed to load reduction of ammonium and TSS from urban areas, and nitrate from cropland while TP should be a target for both.

Subsurface sounders

NASA Technical Reports Server (NTRS)

1975-01-01

Airborne or spaceborne electromagnetic systems used to detect subsurface features are discussed. Data are given as a function of resistivity of ground material, magnetic permeability of free space, and angular frequency. It was noted that resistivities vary with the water content and temperature.

Prospects of passive radio detection of a subsurface ocean on Europa with a lander

NASA Astrophysics Data System (ADS)

Romero-Wolf, Andrew; Schroeder, Dustin M.; Ries, Paul; Bills, Bruce G.; Naudet, Charles; Scott, Bryan R.; Treuhaft, Robert; Vance, Steve

2016-09-01

We estimate the sensitivity of a lander-based instrument for the passive radio detection of a subsurface ocean beneath the ice shell of Europa, expected to be between 3 km and 30 km thick, using Jupiter's decametric radiation. A passive technique was previously studied for an orbiter. Using passive detection in a lander platform provides a point measurement with significant improvements due to largely reduced losses from surface roughness effects, longer integration times, and diminished dispersion due to ionospheric effects allowing operation at lower frequencies and a wider band. A passive sounder on-board a lander provides a low resource instrument sensitive to subsurface ocean at Europa up to depths of 6.9 km for high loss ice (16 dB/km two-way attenuation rate) and 69 km for pure ice (1.6 dB/km).

Prognosis of flow conditions for de-centralized seepage of rainwater from roads

NASA Astrophysics Data System (ADS)

Meyer, Martin; Hasan, Issa; Sallwey, Jana; Graeber, Peter-Wolfgang

2013-04-01

Urbanization programs that include the construction of new settlements or roads lead to an increase in surface sealing. Conventional road drainage is being carried out by a rainwater sewage system coupled with collection and detention basins. This leads to local decreases in evaporation and groundwater recharge, disturbing the natural local water balance. The increased number of climate changed induced extreme precipitation events leads to a higher risk of road floodings as a result of a failure of these systems. Furthermore, the treatment of the discharge loaded with contaminants (such as heavy metals and MTBE) is resolved neither ecologically nor technologically. By using a natural, effective and sustainable evaporation and drainage strategy it is possible to reduce the probability of road floodings, to restore the natural local water balance and to establish ecologically and economically more beneficial rainwater drainage. By using PCSiWaPro®, a simulation tool for unsaturated soil zone processes developed at the Institute of Waste Management and the Technical University of Dresden, the effects of different atmospheric, hydrological and hydrogeological parameters and system conditions on the subsurface drainage flow conditions in the vicinity of a typical German highway road were studied. Special attention was given to the influence of extreme precipitation events on the drainage time at differently tilted parts of the surface, on surface drainages from lateral noise-protection barriers and on the probability of road surface underwashing. Differently constructed upper soil stratifications were tested for their ability to quickly drain water into the ground, which, besides the reduced risk of road flooding, also influence the duration time for the drainage water in each soil layer. Individual rainwater infiltration rates were applied for different regions of the model. The behaviours of three different types of soil (coarse sand, slightly silty sand and medium silty sand) were tested for their applicability as road base materials. The simulation results showed that for extreme precipitation events, the optimized decentralized road drainage system was able to discharge the accumulated rainwater. In future applications, the unsaturated flow model will be extended to a reactive transport model in order to develop strategies for optimal local drainage system design with special regard to natural purification features of different soil layer types. Additionally, PCSiWaPro® can be coupled to a groundwater model to simulate the influence of potential local groundwater contamination by road discharge on the whole underlying aquifer.

In Situ Biotreatment of TBA with Recirculation/Oxygenation

PubMed Central

North, Katharine P.; Mackay, Douglas M.; Kayne, Julian S.; Petersen, Daniel; Rasa, Ehsan; Rastegarzadeh, Laleh; Holland, Reef B.; Scow, Kate M.

2012-01-01

The potential for in situ biodegradation of tert-butyl alcohol (TBA) by creation of aerobic conditions in the subsurface with recirculating well pairs was investigated in two field studies conducted at Vandenberg Air Force Base (VAFB). In the first experiment, a single recirculating well pair with bromide tracer and oxygen amendment successfully delivered oxygen to the subsurface for 42 days. TBA concentrations were reduced from approximately 500 μg/L to below the detection limit within the treatment zone and the treated water was detected in a monitoring transect several meters downgradient. In the second experiment, a site-calibrated model was used to design a double recirculating well pair with oxygen amendment, which successfully delivered oxygen to the subsurface for 291 days and also decreased TBA concentrations to below the detection limit. Methylibium petroleiphilum strain PM1, a known TBA-degrading bacterium, was detectable at the study site but addition of oxygen had little impact on the already low baseline population densities, suggesting that there was not enough carbon within the groundwater plume to support significant new growth in the PM1 population. Given favorable hydrogeologic and geochemical conditions, the use of recirculating well pairs to introduce dissolved oxygen into the subsurface is a viable method to stimulate in situ biodegradation of TBA or other aerobically-degradable aquifer contaminants. PMID:23358537

In Situ Biotreatment of TBA with Recirculation/Oxygenation.

PubMed

North, Katharine P; Mackay, Douglas M; Kayne, Julian S; Petersen, Daniel; Rasa, Ehsan; Rastegarzadeh, Laleh; Holland, Reef B; Scow, Kate M

2012-01-01

The potential for in situ biodegradation of tert-butyl alcohol (TBA) by creation of aerobic conditions in the subsurface with recirculating well pairs was investigated in two field studies conducted at Vandenberg Air Force Base (VAFB). In the first experiment, a single recirculating well pair with bromide tracer and oxygen amendment successfully delivered oxygen to the subsurface for 42 days. TBA concentrations were reduced from approximately 500 μg/L to below the detection limit within the treatment zone and the treated water was detected in a monitoring transect several meters downgradient. In the second experiment, a site-calibrated model was used to design a double recirculating well pair with oxygen amendment, which successfully delivered oxygen to the subsurface for 291 days and also decreased TBA concentrations to below the detection limit. Methylibium petroleiphilum strain PM1, a known TBA-degrading bacterium, was detectable at the study site but addition of oxygen had little impact on the already low baseline population densities, suggesting that there was not enough carbon within the groundwater plume to support significant new growth in the PM1 population. Given favorable hydrogeologic and geochemical conditions, the use of recirculating well pairs to introduce dissolved oxygen into the subsurface is a viable method to stimulate in situ biodegradation of TBA or other aerobically-degradable aquifer contaminants.

The usefulness of adding p53 immunocytochemistry to bile drainage cytology for the diagnosis of malignant biliary strictures.

PubMed

Yeo, Min-Kyung; Kim, Kyung-Hee; Lee, Yong-Moon; Lee, Byung Seok; Choi, Song-Yi

2017-07-01

Obstructive jaundice is frequently caused by bile duct strictures. Determination of malignant strictures is crucial for the initiation of appropriate treatment. Cytologic examination of bile drainage fluid is an easy and reproducible method of detecting malignant cells. This method, however, frequently yields indeterminate results, such as atypia or suspicious of malignancy, due to difficulties in differentiating malignancy from benign atypia. Immunocytochemical assessment of p53 expression by cells in bile drainage fluid may enhance the ability to detect malignancy. A total of 139 samples of bile drainage fluid were obtained from 80 patients. Following cytologic examination, the samples were incubated with antibody to p53. The performance of cytology with and without p53 immunocytochemistry was evaluated, with reference to surgical or clinical findings of benign and malignant biliary strictures. Bile drainage cytology alone had a sensitivity of 31.6% and a specificity of 98.4% in the identification of malignant strictures, whereas the combination of p53 immunocytochemistry and bile drainage cytology had a sensitivity of 80.3% and a specificity of 92.1%. P53 immunocytochemistry alone had a sensitivity of 64.5% and a specificity of 92.7% for the identification of malignant strictures in bile drainage samples with atypical cytology, and a sensitivity of 85.0% and a specificity of 100.0% in samples with suspicious of malignancy. The addition of p53 immunocytochemistry to bile drainage cytology can be useful in identifying malignant strictures in samples showing indeterminate results on bile drainage cytology. Diagn. Cytopathol. 2017;45:592-597. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Are there still roles for exocrine bladder drainage and portal venous drainage for pancreatic allografts?

PubMed

Young, Carlton J

2009-02-01

Controversy remains regarding the best methodology of handling exocrine pancreatic fluid and pancreatic venous effluent. Bladder drainage has given way to enteric drainage. However, is there an instance in which bladder drainage is preferable? Also, hyperinsulinemia, as a result of systemic venous drainage (SVD), is claimed to be proatherosclerotic, whereas portal venous drainage (PVD) is more physiologic and less atherosclerotic. Bladder drainage remains a viable method of exocrine pancreas drainage, but evidence is sparse that measuring urinary amylase has a substantial benefit in the early detection of acute rejection in all types of pancreas transplants. Currently, there is no incontrovertible evidence that systemic hyperinsulinemia is proatherosclerotic, whereas recent metabolic studies on SVD and PVD showed that there was no benefit to PVD. Given the advent of newer immunosuppressive agents and overall lower acute rejection rates, the perceived benefit of bladder drainage as a means to measure urinary amylase as an early marker of rejection has not been substantiated. However, there may be a selective role for bladder drainage in 'high risk' pancreases. Also, without a clear-cut metabolic benefit to PVD over SVD, it remains the surgeon's choice as to which method to use.

Applying model abstraction techniques to optimize monitoring networks for detecting subsurface contaminant transport

USDA-ARS?s Scientific Manuscript database

Improving strategies for monitoring subsurface contaminant transport includes performance comparison of competing models, developed independently or obtained via model abstraction. Model comparison and parameter discrimination involve specific performance indicators selected to better understand s...

BIODEGRADATION OF ATRAZINE IN SUBSURFACE ENVIRONMENTS

EPA Science Inventory

The pesticide atrazine is frequently detected in ground water, including ground water used as drinking water. Little information is available on the fate of atrazine in the subsurface, including its biodegradability. The objectives of this study were to evaluate the biodegradabil...

Roadside IED detection using subsurface imaging radar and rotary UAV

NASA Astrophysics Data System (ADS)

Qin, Yexian; Twumasi, Jones O.; Le, Viet Q.; Ren, Yu-Jiun; Lai, C. P.; Yu, Tzuyang

2016-05-01

Modern improvised explosive device (IED) and mine detection sensors using microwave technology are based on ground penetrating radar operated by a ground vehicle. Vehicle size, road conditions, and obstacles along the troop marching direction limit operation of such sensors. This paper presents a new conceptual design using a rotary unmanned aerial vehicle (UAV) to carry subsurface imaging radar for roadside IED detection. We have built a UAV flight simulator with the subsurface imaging radar running in a laboratory environment and tested it with non-metallic and metallic IED-like targets. From the initial lab results, we can detect the IED-like target 10-cm below road surface while carried by a UAV platform. One of the challenges is to design the radar and antenna system for a very small payload (less than 3 lb). The motion compensation algorithm is also critical to the imaging quality. In this paper, we also demonstrated the algorithm simulation and experimental imaging results with different IED target materials, sizes, and clutters.

Fiber Optic Bragg Grating Sensors for Thermographic Detection of Subsurface Anomalies

NASA Technical Reports Server (NTRS)

Allison, Sidney G.; Winfree, William P.; Wu, Meng-Chou

2009-01-01

Conventional thermography with an infrared imager has been shown to be an extremely viable technique for nondestructively detecting subsurface anomalies such as thickness variations due to corrosion. A recently developed technique using fiber optic sensors to measure temperature holds potential for performing similar inspections without requiring an infrared imager. The structure is heated using a heat source such as a quartz lamp with fiber Bragg grating (FBG) sensors at the surface of the structure to detect temperature. Investigated structures include a stainless steel plate with thickness variations simulated by small platelets attached to the back side using thermal grease. A relationship is shown between the FBG sensor thermal response and variations in material thickness. For comparison, finite element modeling was performed and found to agree closely with the fiber optic thermography results. This technique shows potential for applications where FBG sensors are already bonded to structures for Integrated Vehicle Health Monitoring (IVHM) strain measurements and can serve dual-use by also performing thermographic detection of subsurface anomalies.

Detection of microbes in the subsurface

NASA Technical Reports Server (NTRS)

White, David C.; Tunlid, Anders

1989-01-01

The search for evidence of microbial life in the deep subsurface of Earth has implications for the Mars Rover Sampling Return Missions program. If suitably protected environments can be found on Mars then the instrumentation to detect biomarkers could be used to examine the molecular details. Finding a lipid in Martian soil would represent possibly the simplest test for extant or extinct life. A device that could do a rapid extraction possibly using the supercritical fluid technology under development now with a detection of the carbon content would clearly indicate a sample to be returned.

Infrared Photothermal Radiometry.

DTIC Science & Technology

1984-04-10

changes whenever the transmitted thermal wave crosses a void. This provides a means of nondestructive subsurface imaging of defects, and Busse found that...15 In the flash excitation, the excitation beam is modulated by a broad spectrum of Fourier modulation frequencies. In all cases of subsurface imaging , the...technique of Nordal and Kanstad 2 1t 23 is not only good for spectroscopic detection, but also for subsurface imaging applications as well. 2.4 Pulsed

Using dye tracing to establish groundwater flow paths in a limestone marble aquifer, University of California, Santa Cruz, California

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hayes, J.; Bertschinger, V.; Aley, T.

1993-04-01

Areas underlain by karst aquifers are characterized by soluble rock with sinkholes, caves, and a complex underground drainage network. Groundwater issues such as flow direction, well pumping impacts, spring recharge areas, and potential contamination transport routes are greatly complicated by the unique structure of karst aquifers. Standard aquifer analysis techniques cannot be applied unless the structure of the karst aquifer is understood. Water soluble fluorescent dyes are a powerful tool for mapping the irregular subsurface connections and flow paths in karst aquifers. Mapping the subsurface connections allows reasonable estimates of the hydrologic behavior of the aquifer. Two different fluorescent dyesmore » were injected at two points in a limestone karst aquifer system beneath the University of California, Santa Cruz campus. Flow paths in the marble were thought to be closely tied to easily recognized geomorphic alignments of sinkholes associated with fault and fracture zones. The dye tests revealed unexpected and highly complex interconnections. These complex flow paths only partially corresponded to previous surface mapping and aerial photo analysis of fracture systems. Several interfingering but hydrologically unconnected flow paths evidently exist within the cavernous aquifer. For example, dye did not appear at some discharge springs close to the dye injection points, but did appear at more distant springs. This study shows how a dye tracing study in a small, well-defined limestone body can shed light on a variety of environmental and hydrological issues, including potential well pumping impact areas, wellhead protection and recharge areas, parking lot runoff injection to aquifers, and drainage routes from hazardous materials storage areas.« less

Green Infrastructure, Groundwater and the Sustainable City

NASA Astrophysics Data System (ADS)

Band, L. E.

2014-12-01

The management of water is among the most important attributes of urbanization. Provision of sufficient quantities and quality of freshwater, treatment and disposal of wastewater and flood protection are critical for urban sustainability. Over the last century, two major shifts in water management paradigms have occurred, the first to improve public health with the provision of infrastructure for centralized sanitary effluent collection and treatment, and the rapid drainage and routing of stormwater. A current shift in paradigm is now occurring in response to the unintended consequences of sanitary and stormwater management, which have degraded downstream water bodies and shifted flood hazard downstream. Current infrastructure is being designed and implemented to retain, rather than rapidly drain, stormwater, with a focus on infiltration based methods. In urban areas, this amounts to a shift in hydrologic behavior to depression focused recharge. While stormwater is defined as surface flow resulting from developed areas, an integrated hydrologic systems approach to urban water management requires treatment of the full critical zone. In urban areas this extends from the top of the vegetation and building canopy, to a subsurface depth including natural soils, fill, saprolite and bedrock. In addition to matric and network flow in fracture systems, an urban "karst" includes multiple generations of current and past infrastructure, which has developed extensive subsurface pipe networks for supply and drainage, enhancing surface/groundwater flows and exchange. In this presentation, Band will discuss the need to focus on the urban critical zone, and the development and adaptation of new modeling and analytical approaches to understand and plan green infrastructure based on surface/groundwater/ecosystem interactions, and implications for the restoration and new design of cities.

3-D Resistivity Tomography for Cliff Stability Study at the D-Day Pointe du Hoc Historic Site in Normandy, France

NASA Astrophysics Data System (ADS)

Udphuay, S.; Everett, M. E.; Guenther, T.; Warden, R. R.

2007-12-01

The D-Day invasion site at Pointe du Hoc in Normandy, France is one of the most important World War II battlefields. The site remains today a valuable historic cultural resource. However the site is vulnerable to cliff collapses that could endanger the observation post building and U.S. Ranger memorial located just landward of the sea stack, and an anti-aircraft gun emplacement, Col. Rudder's command post, located on the cliff edge about 200 m east of the observation post. A 3-D resistivity tomography incorporating extreme topography is used in this study to provide a detailed site stability assessment with special attention to these two buildings. Multi-electrode resistivity measurements were made across the cliff face and along the top of the cliff around the two at-risk buildings to map major subsurface fracture zones and void spaces that could indicate possible accumulations and pathways of groundwater. The ingress of acidic groundwater through the underlying carbonate formations enlarges pre-existing tectonic fractures via limestone dissolution and weakens the overall structural integrity of the cliff. The achieved 3-D resistivity tomograms provide diagnostic subsurface resistivity distributions. Resistive zones associated with subsurface void spaces have been located. These void spaces constitute a stability geohazard as they become significant drainage routes during and after periods of heavy rainfalls.

Clinical study on minimally invasive liquefaction and drainage of intracerebral hematoma in the treatment of hypertensive putamen hemorrhage.

PubMed

Liang, Ke-Shan; Ding, Jian; Yin, Cheng-Bin; Peng, Li-Jing; Liu, Zhen-Chuan; Guo, Xiao; Liang, Shu-Yu; Zhang, Yong; Zhou, Sheng-Nian

2017-12-04

This study aims to compare the curative effect of different treatment methods of hypertensive putamen hemorrhage, in order to determine an ideal method of treatment; and to explore the curative effect of the application of soft channel technology-minimally invasive liquefaction and drainage of intracerebral hematoma in the treatment of hypertensive putamen hemorrhage. Patients with hypertensive cerebral hemorrhage, who were treated in our hospital from January 2015 to January 2016, were included into this study. Patients were divided into three groups: minimally invasive drainage group, internal medical treatment group and craniotomy group. In the minimally invasive drainage group, puncture aspiration and drainage were performed according to different hematoma conditions detected in brain CT, the frontal approach was selected for putamen and intracerebral hemorrhage, and drainage was reserved until the hematoma disappeared in CT detection. Drug therapy was dominated in the internal medical treatment group, while surgery under general anesthesia was performed to remove the hematoma in the craniotomy group. Post-treatment neurological function defect scores in minimally invasive drainage group and internal medical group were 16.14 ± 11.27 and 31.43 ± 10.42, respectively; and the difference was remarkably significant (P< 0.01). Post-treatment neurological function defect scores in the minimally invasive drainage group and craniotomy group were 16.14 ± 11.27 and 24.20 ± 12.23, respectively; and the difference was statistically significant (P< 0.05). There was a remarkable significant difference in ADL1-2 level during followed-up in survival patients between the minimally invasive drainage group and internal medical treatment group (P< 0.01), and there was a significant difference in followed-up mortality between these two groups (P< 0.01). Clinical observation and following-up results revealed that minimally invasive drainage treatment was superior to internal medical treatment and craniotomy.

Modeling the Hydrologic Response to Changes in Groundcover Conditions Caused by Fire Disturbances

NASA Astrophysics Data System (ADS)

Kikinzon, E.; Atchley, A. L.; Coon, E.; Middleton, R. S.

2016-12-01

Climate change and fire suppression increase wildfire activity, which alters ecosystem functions and can significantly impact hydrological response. Both wildfire and prescribed burns reduce groundcover, affect top layers of subsurface, and change the structure of overland flow pathways. To understand respective effects on surface and subsurface hydrology, it is imperative to accurately represent surface-subsurface interface pre and post-fire, and to model physical processes in groundcover components. We show mechanistic models used to describe physics in two key types of groundcover, litter and duff, in Advanced Terrestrial Simulator (ATS). Litter is considered to be a part of vegetative canopy covering the surface. It has associated water storage capacity, which allows simulating interception and drainage, and its thickness is used to evaluate surface roughness with potential effect of slowing overland flow compared to bare soil. Duff on the other hand is incorporated into the subsurface, thus requiring meshing and discretization capability to support complex geometries including pinchouts, which is necessary both for achieving desired mesh resolution and portraying bare soil patches without adversely affecting the time scale. As part of the subsurface, duff has its own hydrologic and water retention properties used to resolve infiltration and saturation limited runoff generation, run on, and infiltration processes. This enables the use of ATS for fine scale modeling of integrated hydrology with adequate representation of groundcover influence. To isolate the impact of changing groundcover, we consider a simple hill slope and study the hydrological response to varying amount and geometries of groundcover. To cover landscape characteristics produced by a wide variety of fire conditions, from high intensity to low intensity fire impacts, we simulate hydrologic response to precipitation events over a number of typical geometries and with fine control over amounts of two described types of groundcover. We then analyze hydrological sensitivity to presence or absence of particular groundcover types, their respective patchiness, and possible changes in overland flow pathways.

COUPLED GEOPHYSICAL-HYDROLOGICAL MODELING OF A CONTROLLED NAPL SPILL

EPA Science Inventory

Past studies have shown reasonable sensitivity of geophysical data for detecting or monitoring the movement of non-aqueous phase liquids (NAPLs) in the subsurface. However, heterogeneity in subsurface properties and in NAPL distribution commonly results in non-unique data

...

Impact of Tile Drainage on the Distribution of Concentration and Age of Inorganic Soil Nitrogen.

NASA Astrophysics Data System (ADS)

Woo, D.; Kumar, P.

2017-12-01

Extensive network of tile drainage network across the Midwestern United States, northern Europe and other regions of the world have enhanced agricultural productivity. Because of its impact on sub-surface flow patterns and moisture and temperature dynamics, it controls the nitrogen cycle in agricultural systems, and its influence on nitrogen dynamics plays a key role in determining the short- and long-term evolution of soil inorganic nitrogen concentration and age. The spatial mapping of nitrogen concentration and age under tile-drained fields has, therefore, the potential to open up novel solution to the vexing challenge of reducing environmental impacts while at the same time maintaining agricultural productivity. The objective of this study is to explore the impacts of tile drains on the age dynamics of nitrate, immobile ammonium, mobile ammonia/um, and non-reactive tracer (such as chloride) by implementing two mobile interacting pore domains to capture matrix and preferential flow paths in a coupled ecohydrology and biogeochemistry model, Dhara. We applied this model to an agricultural farm supporting a corn-soybean rotation in the Midwestern United States. It should be expected that the installation of tile drains decrease the age of soil nutrient due to nutrient losses through tile drainage. However, an increase in the age of mobile ammonia/um is observed in contrast to the cases for nitrate, immobile ammonium, and non-reactive tracer. These results arise because the depletion of mobile ammonia/um due to tile drainage causes a high mobility flux from immobile ammonium to mobile ammonia/um, which also carries a considerable amount of relatively old age of immobile ammonium to mobile ammonia/um. In addition, the ages of nitrate and mobile ammonia/um in tile drainage range from 1 to 3 years, and less than a year, respectively, implying that not considering age transformations between nitrogen species would result in substantial underestimation of nitrogen ages, possibly leading to an erroneous conclusion.

Contributions of systematic tile drainage to watershed-scale phosphorus transport.

PubMed

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 <2% of typical application rates in this watershed, but >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.

Lymphatic drainage patterns of oral maxillary tumors: Approachable locations of sentinel lymph nodes mainly at the cervical neck level.

PubMed

Boeve, Koos; Schepman, Kees-Pieter; Vegt, Bert van der; Schuuring, Ed; Roodenburg, Jan L; Brouwers, Adrienne H; Witjes, Max J

2017-03-01

There is debate if the lymphatic drainage pattern of oral maxillary cancer is to the retropharyngeal lymph nodes or to the cervical lymph nodes. Insight in drainage patterns is important for the indication for neck treatment. The purpose of this study was to identify the lymphatic drainage pattern of oral maxillary cancer via preoperative lymphoscintigraphy. Eleven consecutive patients with oral maxillary cancer treated in our center between December 1, 2012, and April 22, 2016 were studied. Sentinel lymph nodes identified by preoperative lymphoscintigraphy after injection of 99m Tc-nanocolloid and by intraoperative detection using a γ-probe, were surgically removed and histopathologically examined. In 10 patients, sentinel lymph nodes were detected and harvested at cervical levels I, II, or III in the neck. In 2 patients, a parapharyngeal sentinel lymph node was detected. One of the harvested sentinel lymph nodes (1/19) was tumor positive. This study suggests the likelihood of 73% of exclusively cervical level I to III sentinel lymph nodes in oral maxillary cancer. © 2016 Wiley Periodicals, Inc. Head Neck 39: 486-491, 2017. © 2016 Wiley Periodicals, Inc.

The use of multi-channel ground penetrating radar and stream monitoring to investigate the seasonal evolution of englacial and subglacial drainage systems at the terminus of Exit Glacier, Alaska

NASA Astrophysics Data System (ADS)

Kilgore, Susan Marlena

Concerns regarding the issue of climate change and, in particular, the rapid retreat of glaciers around the world, have placed great importance on glacial monitoring. Some of the methods most commonly used to observe glacial change---direct mass balance measurements and remote sensing---provide valuable information about glacier change. However, these methods do not address the englacial and subglacial environments. Surface meltwater that enters englacial and subglacial hydrological networks can contribute to acceleration of ice flow, increased calving on marine-terminating glaciers, surges or outburst floods, and greater overall ablation rates. Because subsurface drainage systems often freeze during the winter and re-form each summer, examining the seasonal evolution of these networks is crucial for assessing the impact that internal drainage may have on the behavior of a glacier each year. The goal of this study is to determine the role englacial and subglacial drainage system evolution plays in influencing summer ablation and discharge at the terminus of Exit Glacier, a small valley glacier located in South-central Alaska. During the summers of 2010 and 2011, we used ground-penetrating radar (GPR) to locate internal drainage features on the lower 100 meters of the glacier. GPR surveys were conducted in June and August of each year in an effort to observe the evolution of the drainage systems over the course of an ablation season. Three antenna frequencies---250, 500, and 800 MHz---were used on a dual frequency GPR so that various resolutions and depths in the ice could be viewed simultaneously. Stream monitoring was conducted to document discharge in the proglacial stream throughout the 2011 season. These data were compared with weather records to differentiate noticeable meltwater releases from precipitation events. Additionally, morphological changes in the glacier were observed through photographic documentation. Throughout the observation period, significant subglacial tunnels appeared, followed by the collapse of terminal ice above the tunnels. This phenomenon was most noticeable in 2011. These observations indicate that the internal drainage systems near the terminus of Exit Glacier became very well-developed each summer, and contributed approximately 75 meters of ice loss between June, 2010 and August, 2011.

Investigation of lunar maria structure from cross-analysis of GRAIL gravity and Kaguya radar data

NASA Astrophysics Data System (ADS)

Zuber, M. T.; Ermakov, A.; Smith, D. E.; Mastroguiseppe, M.; Raguso, M.

2016-12-01

The Lunar Radar Sounder (LRS) on JAXA's Kaguya spacecraft investigated the subsurface structure of the Moon to a depth of a few km. GRAIL gravity models are potentially sensitive to subsurface structure at such depths. GRAIL gravity and LRS radar data are complementary since both are sensitive to density/compositional heterogeneities. Cross-correlation of GRAIL and LRS data has the potential to produce new constraints on the structure and evolution of the lunar maria. Originally, subsurface reflections within the lunar maria were detected with Lunar Sounder Experiment aboard Apollo 17. Subsurface layering was attributed to multiple episodes of volcanism. Later, Kaguya's LRS produced similar measurements but with global-scale coverage. Laboratory measurements show that density variations among mare basalts can be up to 200 kg m-3 or 7%. The LRS measurements have detected subsurface reflection in the upper 1 km of the crust. Combining these two estimates and using the Bouguer slab approximation, we estimate that anomalies of order 1-10 mGal are expected due to potentially varying density of surface and/or subsurface horizons. This accuracy is achievable with the latest GRAIL gravity models. The LRS surface backscattering power is indicative of surface and near sub-surface dielectric properties, which are sensitive to target density and roughness. We investigate the northwestern part of the Procellarum basin because it is the region with the strongest signal-to-noise ratios in gravity models within maria. To examine shallow subsurface structure, we map the surface received power by tracking the first return of radar echoes and compare it with gravity gradients, which are particularly sensitive to small-scale structures.

Detection of Subsurface Material Separation in Shuttle Orbiter Slip-Side Joggle Region of the Wing Leading Edge using Infrared Imaging Data from Arc Jet Tests

NASA Technical Reports Server (NTRS)

Daryabeigi, Kamran; Walker, Sandra P.

2009-01-01

The objective of the present study was to determine whether infrared imaging (IR) surface temperature data obtained during arc-jet tests of Space Shuttle Orbiter s reinforced carbon-carbon (RCC) wing leading edge panel slip-side joggle region could be used to detect presence of subsurface material separation, and if so, to determine when separation occurs during the simulated entry profile. Recent thermostructural studies have indicated thermally induced interlaminar normal stress concentrations at the substrate/coating interface in the curved joggle region can result in local subsurface material separation, with the separation predicted to occur during approach to peak heating during reentry. The present study was an attempt to determine experimentally when subsurface material separations occur. A simplified thermal model of a flat RCC panel with subsurface material separation was developed and used to infer general surface temperature trends due to the presence of subsurface material separation. IR data from previously conducted arc-jet tests on three test specimens were analyzed: one without subsurface material separation either pre or post test, one with pre test separation, and one with separation developing during test. The simplified thermal model trend predictions along with comparison of experimental IR data of the three test specimens were used to successfully infer material separation from the arc-jet test data. Furthermore, for the test specimen that had developed subsurface material separation during the arc-jet tests, the initiation of separation appeared to occur during the ramp up to the peak heating condition, where test specimen temperature went from 2500 to 2800 F.

Ring Resonator for Detection of Melting Brine Under Shallow Subsurface of Mars

NASA Technical Reports Server (NTRS)

Ponchak, George E.; Jordan, Jennifer L.; Scardelletti, Maximillian C.

2016-01-01

Laboratory experimental evidence using Raman spectroscopy has shown that liquid brine may form below the shallow subsurface of Mars. A simpler experimental method to verify the presence of liquid brine or liquid water below Mars surface is needed. In this paper, a ring resonator is used to detect the phase change between frozen water and liquid water below a sandy soil that simulates the Mars surface. Experimental data shows that the ring resonator can detect the melting of thin layers of frozen brine or water up to 15 mm below the surface.

National Dam Safety Program. Wappingers Falls Dam (I.D. Number N.Y. 3, D.E.C. 613A), Hudson River Basin, Dutchess County, New York. Phase 1 Inspection Report

DTIC Science & Technology

1980-09-30

Classification 2I e. Ownership 2f. Purpose of Dam 2 g. Design and Construction History 2h. Normal Operating Procedure 2 1.3 PERTINENT DATA 2 a. Drainage...4 2.2 SUBSURFACE INVESTIGATION 4 2.3 DAM AND APPURTENANT STRUCTURES 4 2.4 CONSTRUCTION RECORDS 4 2.5 OPERATION RECORDS 2.6 EVALUATION OF DATA 5 4...12 a. Visual Observations 12 b. Design and Construction Data 12 c. Stability Analysis 12 d. Operating Records 13 e. Post- Construction Changes 13 f

Lateral, vertical, and longitudinal connectivity of runoff source areas drive stream hydro-biogeochemical signals across a low relief drainage network

NASA Astrophysics Data System (ADS)

Zimmer, M. A.; McGlynn, B. L.

2017-12-01

Our understanding of the balance between longitudinal, lateral, and vertical expansion and contraction of reactive flowpaths and source areas in headwater catchments is limited. To address this, we utilized an ephemeral-to-perennial stream network in the Piedmont region of North Carolina, USA to gain new understanding about critical zone mechanisms that drive runoff generation and biogeochemical signals in both groundwater and stream water. Here, we used chemical and hydrometric data collected from zero through second order catchments to characterize spatial and temporal runoff and overland, shallow soil, and deep subsurface flow across characteristic landscape positions. Our results showed that the active stream network was driven by two superimposed runoff generation regimes that produced distinct hydro-biogeochemical signals at the catchment outlet. The baseflow runoff generation regime expanded and contracted the stream network seasonally through the rise and fall of the seasonal water table. Superimposed on this, event-activated source area contributions were driven by surficial and shallow subsurface flowpaths. The subsurface critical zone stratigraphy in this landscape coupled with the precipitation regime activated these shallow flowpaths frequently. This drove an increase in dissolved organic carbon (DOC) concentrations with increases in runoff across catchment scales. DOC-runoff relationship variability and spread was driven by the balance between runoff regimes as well as a seasonal depletion of DOC from shallow subsurface flowpath activation and annual replenishment from litterfall. From this, we suggest that the hydro-biogeochemical signals at larger catchment outlets can be driven by a balance of longitudinal, lateral, and vertical source area contributions, critical zone structure, and complex hydrological processes.

Hydrology of two slopes in subarctic Yukon, Canada

NASA Astrophysics Data System (ADS)

Carey, Sean K.; Woo, Ming-Ko

1999-11-01

Two subarctic forested slopes in central Wolf Creek basin, Yukon, were studied in 1996-1997 to determine the seasonal pattern of the hydrologic processes. A south-facing slope has a dense aspen forest on silty soils with seasonal frost only and a north-facing slope has open stands of black spruce and an organic layer on top of clay sediments with permafrost. Snowmelt is advanced by approximately one month on the south-facing slope due to greater radiation receipt. Meltwater infiltrates its seasonally frozen soil with low ice content, recharging the soil moisture reservoir but yielding no lateral surface or subsurface flow. Summer evaporation depletes this recharged moisture and any additional rainfall input, at the expense of surface or subsurface flow. The north-facing slope with an ice rich substrate hinders deep percolation. Snow meltwater is impounded within the organic layer to produce surface runoff in rills and gullies, and subsurface flow along pipes and within the matrix of the organic soil. During the summer, most subsurface flows are confined to the organic layer which has hydraulic conductivities orders of magnitudes larger than the underlying boulder-clay. Evaporation on the north-facing slope declines as both the frost table and the water table descend in the summer. A water balance of the two slopes demonstrates that vertical processes of infiltration and evaporation dominate moisture exchanges on the south-facing slope, whereas the retardation of deep drainage by frost and by clayey soil on the permafrost slope promotes a strong lateral flow component, principally within the organic layer. These results have the important implication that permafrost slopes and organic horizons are the principal controls on streamflow generation in subarctic catchments.

Development and application of a hillslope hydrologic model

USGS Publications Warehouse

Blain, C.A.; Milly, P.C.D.

1991-01-01

A vertically integrated two-dimensional lateral flow model of soil moisture has been developed. Derivation of the governing equation is based on a physical interpretation of hillslope processes. The lateral subsurface-flow model permits variability of precipitation and evapotranspiration, and allows arbitrary specification of soil-moisture retention properties. Variable slope, soil thickness, and saturation are all accommodated. The numerical solution method, a Crank-Nicolson, finite-difference, upstream-weighted scheme, is simple and robust. A small catchment in northeastern Kansas is the subject of an application of the lateral subsurface-flow model. Calibration of the model using observed discharge provides estimates of the active porosity (0.1 cm3/cm3) and of the saturated horizontal hydraulic conductivity (40 cm/hr). The latter figure is at least an order of magnitude greater than the vertical hydraulic conductivity associated with the silty clay loam soil matrix. The large value of hydraulic conductivity derived from the calibration is suggestive of macropore-dominated hillslope drainage. The corresponding value of active porosity agrees well with a published average value of the difference between total porosity and field capacity for a silty clay loam. ?? 1991.

Nematoda from the terrestrial deep subsurface of South Africa.

PubMed

Borgonie, G; García-Moyano, A; Litthauer, D; Bert, W; Bester, A; van Heerden, E; Möller, C; Erasmus, M; Onstott, T C

2011-06-02

Since its discovery over two decades ago, the deep subsurface biosphere has been considered to be the realm of single-cell organisms, extending over three kilometres into the Earth's crust and comprising a significant fraction of the global biosphere. The constraints of temperature, energy, dioxygen and space seemed to preclude the possibility of more-complex, multicellular organisms from surviving at these depths. Here we report species of the phylum Nematoda that have been detected in or recovered from 0.9-3.6-kilometre-deep fracture water in the deep mines of South Africa but have not been detected in the mining water. These subsurface nematodes, including a new species, Halicephalobus mephisto, tolerate high temperature, reproduce asexually and preferentially feed upon subsurface bacteria. Carbon-14 data indicate that the fracture water in which the nematodes reside is 3,000-12,000-year-old palaeometeoric water. Our data suggest that nematodes should be found in other deep hypoxic settings where temperature permits, and that they may control the microbial population density by grazing on fracture surface biofilm patches. Our results expand the known metazoan biosphere and demonstrate that deep ecosystems are more complex than previously accepted. The discovery of multicellular life in the deep subsurface of the Earth also has important implications for the search for subsurface life on other planets in our Solar System.

Optimal Electromagnetic (EM) Geophysical Techniques to Map the Concentration of Subsurface Ice and Adsorbed Water on Mars and the Moon

NASA Astrophysics Data System (ADS)

Stillman, D. E.; Grimm, R. E.

2013-12-01

Water ice is ubiquitous in our Solar System and is a probable target for planetary exploration. Mapping the lateral and vertical concentration of subsurface ice from or near the surface could determine the origin of lunar and martian ice and quantify a much-needed resource for human exploration. Determining subsurface ice concentration on Earth is not trivial and has been attempted previously with electrical resistivity tomography (ERT), ground penetrating radar (GPR), airborne EM (AEM), and nuclear magnetic resonance (NMR). These EM geophysical techniques do not actually detect ice, but rather the absence of unfrozen water. This causes a non-unique interpretation of frozen and dry subsurface sediments. This works well in the arctic because most locations are not dry. However, for planetary exploration, liquid water is exceedingly rare and subsurface mapping must discriminate between an ice-rich and a dry subsurface. Luckily, nature has provided a unique electrical signature of ice: its dielectric relaxation. The dielectric relaxation of ice creates a temperature and frequency dependence of the electrical properties and varies the relative dielectric permittivity from ~3.1 at radar frequencies to >100 at low frequencies. On Mars, sediments smaller than silt size can hold enough adsorbed unfrozen water to complicate the measurement. This is because the presence of absorbed water also creates frequency-dependent electrical properties. The dielectric relaxation of adsorbed water and ice can be separated as they have different shapes and frequency ranges as long as a spectrum spanning the two relaxations is measured. The volume concentration of ice and adsorbed water is a function of the strength of their relaxations. Therefore, we suggest that capacitively-coupled dielectric spectroscopy (a.k.a. spectral induced polarization or complex resistivity) can detect the concentration of both ice and adsorbed water in the subsurface. To prove this concept we have collected dielectric spectroscopy at the Cold Regions Research and Engineering Laboratory (CRREL) permafrost tunnel in Fox, AK. We were able to detect the ice relaxation in the subsurface despite the considerable amount of subsurface unfrozen water due to the presence of montmorillonite clay and much warmer temperatures than Mars or permanently shadowed regions of the Moon. While dielectric spectroscopy can be used to determine ice and adsorbed water content it does not possess the high resolution mapping capability of a GPR. Moreover, GPR cannot detect subsurface ice content in ice-sediment mixtures as evidenced in the interpretation of the Medusae Fossae Formation. Orbital radar surveys show this unit has a low attenuation and a dielectric permittivity near 4. This allows the formation to be interpreted as ice-rich or a dry high-porosity volcanic tuff unit. Therefore, combining GPR and dielectric spectroscopy will enable high-resolution structural and volatile mapping of the subsurface. Furthermore, the addition of neutron spectroscopy would add total hydrogen abundance in the top meter. This could lead to the determination of how much hydrogen resides in ice, adsorbed water, and minerals.

Nde of Frp Wrapped Columns Using Infrared Thermography

NASA Astrophysics Data System (ADS)

Halabe, Udaya B.; Dutta, Shasanka Shekhar; GangaRao, Hota V. S.

2008-02-01

This paper investigates the feasibility of using Infrared Thermography (IRT) for detecting debonds in Fiber Reinforced Polymer (FRP) wrapped columns. Laboratory tests were conducted on FRP wrapped concrete cylinders of size 6″×12″ (152.4 mm×304.8 mm) in which air-filled and water-filled debonds of various sizes were placed underneath the FRP wraps. Air-filled debonds were made by cutting plastic sheets into the desired sizes whereas water-filled debonds were made by filling water in custom made polyethylene pouches. Both carbon and glass fiber reinforced wraps were considered in this study. Infrared tests were conducted using a fully radiometric digital infrared camera which was successful in detecting air-filled as well as water-filled subsurface debonds. In addition to the laboratory testing, two field trips were made to Moorefield, West Virginia for detecting subsurface debonds in FRP wrapped timber piles of a railroad bridge using infrared testing. The results revealed that infrared thermography can be used as an effective nondestructive evaluation tool for detecting subsurface debonds in structural components wrapped with carbon or glass reinforced composite fabrics.

Detection of stiff nanoparticles within cellular structures by contact resonance atomic force microscopy subsurface nanomechanical imaging.

PubMed

Reggente, Melania; Passeri, Daniele; Angeloni, Livia; Scaramuzzo, Francesca Anna; Barteri, Mario; De Angelis, Francesca; Persiconi, Irene; De Stefano, Maria Egle; Rossi, Marco

2017-05-04

Detecting stiff nanoparticles buried in soft biological matrices by atomic force microscopy (AFM) based techniques represents a new frontier in the field of scanning probe microscopies, originally developed as surface characterization methods. Here we report the detection of stiff (magnetic) nanoparticles (NPs) internalized in cells by using contact resonance AFM (CR-AFM) employed as a potentially non-destructive subsurface characterization tool. Magnetite (Fe 3 O 4 ) NPs were internalized in microglial cells from cerebral cortices of mouse embryos of 18 days by phagocytosis. Nanomechanical imaging of cells was performed by detecting the contact resonance frequencies (CRFs) of an AFM cantilever held in contact with the sample. Agglomerates of NPs internalized in cells were visualized on the basis of the local increase in the contact stiffness with respect to the surrounding biological matrix. A second AFM-based technique for nanomechanical imaging, i.e., HarmoniX™, as well as magnetic force microscopy and light microscopy were used to confirm the CR-AFM results. Thus, CR-AFM was demonstrated as a promising technique for subsurface imaging of nanomaterials in biological samples.

Advanced Algorithms and High-Performance Testbed for Large-Scale Site Characterization and Subsurface Target Detecting Using Airborne Ground Penetrating SAR

NASA Technical Reports Server (NTRS)

Fijany, Amir; Collier, James B.; Citak, Ari

1997-01-01

A team of US Army Corps of Engineers, Omaha District and Engineering and Support Center, Huntsville, let Propulsion Laboratory (JPL), Stanford Research Institute (SRI), and Montgomery Watson is currently in the process of planning and conducting the largest ever survey at the Former Buckley Field (60,000 acres), in Colorado, by using SRI airborne, ground penetrating, Synthetic Aperture Radar (SAR). The purpose of this survey is the detection of surface and subsurface Unexploded Ordnance (UXO) and in a broader sense the site characterization for identification of contaminated as well as clear areas. In preparation for such a large-scale survey, JPL has been developing advanced algorithms and a high-performance restbed for processing of massive amount of expected SAR data from this site. Two key requirements of this project are the accuracy (in terms of UXO detection) and speed of SAR data processing. The first key feature of this testbed is a large degree of automation and a minimum degree of the need for human perception in the processing to achieve an acceptable processing rate of several hundred acres per day. For accurate UXO detection, novel algorithms have been developed and implemented. These algorithms analyze dual polarized (HH and VV) SAR data. They are based on the correlation of HH and VV SAR data and involve a rather large set of parameters for accurate detection of UXO. For each specific site, this set of parameters can be optimized by using ground truth data (i.e., known surface and subsurface UXOs). In this paper, we discuss these algorithms and their successful application for detection of surface and subsurface anti-tank mines by using a data set from Yuma proving Ground, A7, acquired by SRI SAR.

Competing feedbacks drive state transitions during initial catchment evolution: Examples from post-mining landscape and ecosystems evolution

NASA Astrophysics Data System (ADS)

Hinz, Christoph; Wolfgang, Schaaf; Werner, Gerwin

2014-05-01

Within the context of severely disturbed landscapes with little or no ecological memory, such as post-mining landscapes, we propose a simple framework that explains the catchment evolution as a result of competing feedbacks influenced by the initial conditions and the atmospheric drivers such as rainfall intermittency and intensity. The first stage of the evolution is dominated by abiotic feedbacks triggered by rainfall and subsequent fluid flow causing particle mobilisation on the surface and in the subsurface leading to flow concentration or in some instances to densification of surface and subsurface substrates. Subsequently, abiotic-biotic feedbacks start to compete in the sense that biological activity generally stabilizes substrate by preventing particle mobilisation and hence contribute to converting the substrate to a habitat. We suggest that these competing feedbacks may generate alternative stable states in particular under semi-arid and arid climatic conditions, while in temperate often energy limited environments biological process "outcompete" abiotic processes leading to a stable state, in particular from the water balance point of view for comparable geomorphic situations. To illustrate this framework, we provide examples from post-mining landscapes, in which soil, water and vegetation was monitored. In case of arid regions in Australia, we provide evidence that the initial conditions of a mine waste disposal "locked" the system into a state that was limited by water and nutrient storage capacity while at the same time it was stable from a geomorphic point of view for the observation period. The cause of the system to be locked in, is the very high hydraulic conductivity of the substrate, that has not undergone any changes during the first years. In contrast to this case study, we illustrate how this framework explains the evolution of an artificial catchment (Hühnerwasser Catchment) in Lusatia (150 km southeast of Berlin, Germany). During the initial phase of development the catchment changed very rapidly due to sediment transport, drainage network formation, and soil crusting very similar to geomorphic processes observed in arid and semi-arid landscapes void of dense vegetation. Hydraulic properties changed rapidly after few wet and dry cycles, indicative of particle mobilisation and trapping in the subsurface. Accordingly, the hydrological regime was controlled by rapid surface runoff enhanced through crust formation and at the same time a shallow ground water system developed. This surface runoff regime peeked about two years initialisation as shown by a maximum area of drainage channels. A major, fairly rapid transition occurred between three and five years after placement, in which the sediment transport ceased and vegetation coverage of the drainage channel exceeded 90%. The transition represents the onset of a transpiration dominated regime that is further enhanced by change of the plant composition of the vegetation with tree recruitment from the surrounding forming significant clusters in the catchment. This transition in the third year was also seen in a significant increase in soil fauna and plant diversity.

A Specific Mapping Study Using Fluorescence Sentinel Lymph Node Detection in Patients with Intermediate- and High-risk Prostate Cancer Undergoing Extended Pelvic Lymph Node Dissection.

PubMed

Nguyen, Daniel P; Huber, Philipp M; Metzger, Tobias A; Genitsch, Vera; Schudel, Hans H; Thalmann, George N

2016-11-01

Sentinel lymph node (SLN) detection techniques have the potential to change the standard of surgical care for patients with prostate cancer. We performed a lymphatic mapping study and determined the value of fluorescence SLN detection with indocyanine green (ICG) for the detection of lymph node metastases in intermediate- and high-risk patients undergoing radical prostatectomy and extended pelvic lymph node dissection. A total of 42 patients received systematic or specific ICG injections into the prostate base, the midportion, the apex, the left lobe, or the right lobe. We found (1) that external and internal iliac regions encompass the majority of SLNs, (2) that common iliac regions contain up to 22% of all SLNs, (3) that a prostatic lobe can drain into the contralateral group of pelvic lymph nodes, and (4) that the fossa of Marcille also receives significant drainage. Among the 12 patients who received systematic ICG injections, 5 (42%) had a total of 29 lymph node metastases. Of these, 16 nodes were ICG positive, yielding 55% sensitivity. The complex drainage pattern of the prostate and the low sensitivity of ICG for the detection of lymph node metastases reported in our study highlight the difficulties related to the implementation of SNL techniques in prostate cancer. There is controversy about how extensive lymph node dissection (LND) should be during prostatectomy. We investigated the lymphatic drainage of the prostate and whether sentinel node fluorescence techniques would be useful to detect node metastases. We found that the drainage pattern is complex and that the sentinel node technique is not able to replace extended pelvic LND. Copyright © 2016. Published by Elsevier B.V.

SPECIATION OF SUBSURFACE CONTAMINANTS BY CONE PENETROMETRY GAS CHROMATOGRAPHY/MASS SPECTROMETRY. (R826184)

EPA Science Inventory

A thermal extraction cone penetrometry gas chroma tography/mass spectrometry system (TECP GC/MS) has been developed to detect subsurface contaminants in situ. The TECP can collect soil-bound organics up to depths of 30 m. In contrast to traditional cone penetrometer sample collec...

EVALUATION OF GEOPHYSICAL METHODS FOR THE DETECTION OF SUBSURFACE TETRACHLOROETHYLENE (PCE) IN CONTROLLED SPILL EXPERIMENTS

EPA Science Inventory

Tetrachloroethylene (PCE), typically used as a dry cleaning solvent, is a predominant contaminant in the subsurface at Superfund Sites. PCE is a dense non-aqueous phase liquid (DNAPL) that migrates downward into the earth, leaving behind areas of residual saturation and free prod...

SUBSURFACE CHARACTERIZATION AND MONITORING TECHNIQUES: A DESK REFERENCE GUIDE - VOLUME I: SOLIDS AND GROUND WATER - APPENDICES A AND B

EPA Science Inventory

Many EPA programs, including those under the Resource Conservation and Recovery Act (RCRA) and the Comprehensive Response, Compensation, and Liability Act (CERCLA), require subsurface characterization and monitoring to detect ground-water contamination and provide data to devel...

Chemical and microbiological water quality of subsurface agricultural drains during a field trial of liquid dairy manure effluent application rate and varying tillage practices, Upper Tiffin Watershed, southeastern Michigan

USGS Publications Warehouse

Haack, Sheridan Kidd; Duris, Joseph W.

2008-01-01

A field trial was done in the Upper Tiffin River Watershed, in southeastern Michigan, to determine the influence of liquid dairy manure effluent (LDME) management practices on the quality of agricultural subsurface-drain water. Samples from subsurface drains were analyzed for nutrients, fecal-coliform and Escherichia coli (E. coli) bacteria, antibiotics, chemicals typically detected in wastewater, and the occurrence of genes indicating the presence of shiga-toxin-producing E. coli, or of bovine-specific Bacteroidetes bacteria. Samples were collected from November 2, 2006, to March 20, 2007, from eight subsurface drains under field plots that received no LDME and no tillage (controls) or received 4,000 or 8,000 gallons per acre (gal/acre) of LDME and either no tillage or two different types of tillage. The two types of tillage tested were (1) ground-driven, rotary, subsurface cultivation and (2) rolling-tine aeration. Samples were collected before LDME application and at 4 hours, and 1, 2, 6, 7, and 14 days post-application. Nutrient concentrations were high in subsurface-drain water throughout the field-trial period and could not be attributed to the field-trial LDME application. Of the 59 drain-water samples, including those collected before LDME application and control samples for each date, 56 had concentrations greater than the U.S. Environmental Protection Agency (USEPA), Ecoregion VI recommended surface-water criterion for total phosphorus, and all samples had concentrations greater than the recommended total nitrogen criterion. Nitrate + nitrite nitrogen concentration exceeded 20 milligrams per liter for every sample and contributed most to the total nitrogen concentrations. Substantial increases in drain-water concentrations of organic and ammonia nitrogen and total phosphorus were found for all treatments, including controls, at 14 days post-application after 0.84 inch of rainfall over 2 days. E. coli concentrations exceeded the USEPA recreational-water-quality single-sample criterion of 235 colony forming units per 100 milliliters in only 3 of 56 samples. Of these three samples, two were collected within 1 day post-LDME application from the treatment receiving 8,000 gal/acre LDME with no tillage (NT8000). The third sample was from the rolling-tine aerator treatment with 4,000 gal/acre LDME application rate after the first significant rainfall. Two wastewater chemicals and two bacterial genes (eaeA and stx1) detected in the LDME, but absent in field blank or pre-application samples, were detected in the 4-hour or 1-day postapplication NT8000 samples. No LDME-associated chemicals were detected in later samples from the NT8000 treatment, and none were detected in samples from other treatments after the first significant rainfall. Results of this field trial were somewhat equivocal with respect to the influence of LDME concentration and tillage practices on subsurface-drain water quality, both immediately after LDME application and in the longer term, after significant rainfall. Interpretation of study findings is limited by the fact that treatments were not replicated, and flow rate or discharge from the subsurface drains was not measured. Nevertheless, study results provide useful information about nutrient and bacteria concentrations in subsurface drains during the non-growing season. In addition, study results demonstrate some potential for the use of chemical and microbiological indicators of LDME transport to subsurface drains.

Brominated flame retardants and perfluoroalkyl acids in groundwater, tile drainage, soil, and crop grain following a high application of municipal biosolids to a field.

PubMed

Gottschall, N; Topp, E; Edwards, M; Payne, M; Kleywegt, S; Lapen, D R

2017-01-01

Dewatered municipal biosolids (DMB) were applied at a rate of 22Mgdwha -1 to an agricultural field in fall 2008. Concentrations of polybrominated diphenyl ethers (PBDEs; BDE-47, -99, -100, -153, -154, -183, -197, -207, -209), other brominated flame retardants (BFRs; HBB, PBEB, DBDPE, BTBPE) and perfluoroalkyl acids (PFAAs; PFHxS, PFOS, PFDS, PFOSA, PFHpA, PFOA, PFNA, PFDA, PFUnA, PFDoA, PFTA) were monitored in tile drainage, groundwater (2m, 4m and 6m depth), soil cores (0-0.3m) pre- and post-application, DMB aggregates incorporated into the soil post-application, and in wheat (Triticum spp.) planted post-application. Several compounds were detected in soil and water pre-application and on a reference field plot. PBDEs, other BFRs and PFAAs were detected in tile drainage and 2m groundwater throughout the post-application study period; a few PBDEs were also detected sporadically at lower depths in groundwater. Some of these compounds had not been detected pre-application, while some exceeded reference field plot/pre-application levels (some significantly (p<0.05) in tile drainage); both cases indicating biosolid-based water contamination. In DMB aggregates, several PBDE congeners were found to have dissipated exponentially, with reductions >90% in many of them within 1year post-application. Exponential dissipation of other BFRs and PFAAs in DMB aggregates were not significant. No PBDEs, other BFRs, or PFAAs were detected in wheat grain. Crown Copyright © 2016. Published by Elsevier B.V. All rights reserved.

Quantification of metal loads by tracer injection and synoptic sampling in Daisy Creek and the Stillwater River, Park County, Montana, August 1999

USGS Publications Warehouse

Nimick, David A.; Cleasby, Thomas E.

2001-01-01

A metal-loading study using tracer-injection and synoptic-sampling methods was conducted in Daisy Creek and a short reach of the Stillwater River during baseflow in August 1999 to quantify the metal inputs from acid rock drainage in the New World Mining District near Yellowstone National Park and to examine the downstream transport of these metals into the Stillwater River. Loads were calculated for many mainstem and inflow sites by combining streamflow determined using the tracer-injection method with concentrations of major ions and metals that were determined in synoptic water-quality samples. Water quality and aquatic habitat in Daisy Creek have been affected adversely by drainage derived from waste rock and adit discharge at the McLaren Mine as well as from natural weathering of pyrite-rich mineralized rock that comprises and surrounds the ore zones. However, the specific sources and transport pathways are not well understood. Knowledge of the main sources and transport pathways of metals and acid can aid resource managers in planning and conducting effective and cost-efficient remediation activities. The metals cadmium, copper, lead, and zinc occur at concentrations that are sufficiently elevated to be potentially lethal to aquatic life in Daisy Creek and to pose a toxicity risk in part of the Stillwater River. Copper is of most concern in Daisy Creek because it occurs at higher concentrations than the other metals. Acidic surface inflows had dissolved concentrations as high as 20.6 micrograms per liter (?g/L) cadmium, 26,900 ?g/L copper, 76.4 ?g/L lead, and 3,000 ?g/L zinc. These inflows resulted in maximum dissolved concentrations in Daisy Creek of 5.8 ?g/L cadmium, 5,790 ?g/L copper, 3.8 ?g/L lead, and 848 ?g/L zinc. Significant copper loading to Daisy Creek occurred only in the upper half of the stream. Sources included subsurface inflow and right-bank (mined side) surface inflows. Copper loads in left-bank (unmined side) surface inflows were negligible. Most (71 percent) of the total copper loading in the study reach occurred along a 341-foot reach near the stream?s headwaters. About 53 percent of the total copper load was contributed by five surface inflows that drain a manganese bog and the southern part of the McLaren Mine. Copper loading from subsurface inflow was substantial, contributing 46 percent of the total dissolved copper load to Daisy Creek. More than half of this subsurface copper loading occurred downstream from the reaches that received significant surface loading. Flow through the shallow subsurface appears to be the main copper-transport pathway from the McLaren Mine and surrounding altered and mineralized bedrock to Daisy Creek during base-flow conditions. Little is known about the source of acid and copper in this subsurface flow. However, possible sources include the mineralized rocks of Fisher Mountain upgradient of the McLaren Mine area, the surficial waste rock at the mine, and the underlying pyritic bedrock.

Late Cretaceous Turbidite Reservoirs Along the Equatorial West African Margin: An Industry Perspective on Source-to-Sink Relationships

NASA Astrophysics Data System (ADS)

Wilson, Jonathan; Kohlmann, Fabian; Nicoll, Graeme

2017-04-01

The source-to-sink mindset provides an important framework for the exploration geologist. It enables an integrated understanding of hinterland and basin, and can lead to subsurface risk mitigation, particularly with respect to predicting reservoir location and quality. Despite the numerous benefits associated with source-to-sink analysis, such studies are time-consuming to generate, encompassing a large array of disciplines and data, and are not routinely performed within the hydrocarbon industry. The discovery of several significant hydrocarbon fields along the equatorial West African margin has been followed by a series of expensive failures throughout the last decade associated with reservoir quality/presence. This paper discusses a case study focused on the equatorial West African margin, demonstrating how three well-known but effective approaches can be integrated to reconstruct source-to-sink relationships in an ancient sedimentary system, helping de-risk exploration efforts. The first step is to characterize the hinterland. To do this, detailed information was collected for two separate but interlinked datasets—mineral deposits and hard rock geochronology. Combined, these two datasets allow an understanding of the timing and nature of an areas tectonic evolution to be easily developed. The data can be used alongside stratigraphic data and geodynamic information from a plate tectonic model to reconstruct topography and bathymetry of the earth at different episodes of geological time. Paleo digital elevation models (PDEMs) give a first-order approximation of hinterland topography and therefore allow possible sediment source areas to be identified and potential sediment transport pathways to be visualized by means of the digital reconstruction of paleo-drainage networks and their attendant watersheds. This integrated global dataset of hinterland geochronology provides useful "source" information complemented by "sink" information contained within a detrital geochronology database. By combining these two datasets and matching the age populations, sediment provenance can be deduced and source-to-sink relationships can be unraveled. Sedimentary provenance analysis from detrital/hinterland geochronology, and the application of flow routing algorithms to PDEMs, allow for the physical limits of paleo-drainage basins to be reconstructed. Assessment of the nature and composition of the hinterland within individual paleo-drainage basins provides a useful means of predicting the quality of sediment in associated point-sourced depocentres along the margin. For example, the erosion of hinterlands with markedly different compositions can have dramatic effects on the quality of sediment delivered to the surrounding basins. Sediment transport pathways provided by PDEMs and detrital zircon geochronology provide a paleo-drainage network that can be further developed by exploiting power-law scaling relationships observed between source-to-sink systems (Somme et al. 2009). These relationships, and more general predictive models (e.g., Syvitski and Milliman 2007), allow for semiquantitative approximation of morphological and sedimentological parameters in both the source and sink domain and provide a useful means of verifying inferred drainage patterns. In frontier areas where subsurface constraint is sparse, an appreciation of sink characteristics, such as fan size and sediment flux are extremely valuable as a first-pass basin screening tool.

A Mobile Acoustic Subsurface Sensing (MASS) System for Rapid Roadway Assessment

PubMed Central

Lu, Yifeng; Zhang, Yi; Cao, Yinghong; McDaniel, J. Gregory; Wang, Ming L.

2013-01-01

Surface waves are commonly used for vibration-based nondestructive testing for infrastructure. Spectral Analysis of Surface Waves (SASW) has been used to detect subsurface properties for geologic inspections. Recently, efforts were made to scale down these subsurface detection approaches to see how they perform on small-scale structures such as concrete slabs and pavements. Additional efforts have been made to replace the traditional surface-mounted transducers with non-contact acoustic transducers. Though some success has been achieved, most of these new approaches are inefficient because they require point-to-point measurements or off-line signal analysis. This article introduces a Mobile Acoustic Subsurface Sensing system as MASS, which is an improved surface wave based implementation for measuring the subsurface profile of roadways. The compact MASS system is a 3-wheeled cart outfitted with an electromagnetic impact source, distance register, non-contact acoustic sensors and data acquisition/processing equipment. The key advantage of the MASS system is the capability to collect measurements continuously at walking speed in an automatic way. The fast scan and real-time analysis advantages are based upon the non-contact acoustic sensing and fast air-coupled surface wave analysis program. This integration of hardware and software makes the MASS system an efficient mobile prototype for the field test. PMID:23698266

Technical Analysis of In-Valley Drainage Management Strategies for the Western San Joaquin Valley, California

USGS Publications Warehouse

Presser, Theresa S.; Schwarzbach, Steven E.

2008-01-01

The western San Joaquin Valley is one of the most productive farming areas in the United States, but salt-buildup in soils and shallow groundwater aquifers threatens this area?s productivity. Elevated selenium concentrations in soils and groundwater complicate drainage management and salt disposal. In this document, we evaluate constraints on drainage management and implications of various approaches to management considered in: *the San Luis Drainage Feature Re-Evaluation (SLDFRE) Environmental Impact Statement (EIS) (about 5,000 pages of documentation, including supporting technical reports and appendices); *recent conceptual plans put forward by the San Luis Unit (SLU) contractors (i.e., the SLU Plans) (about 6 pages of documentation); *approaches recommended by the San Joaquin Valley Drainage Program (SJVDP) (1990a); and *other U.S. Geological Survey (USGS) models and analysis relevant to the western San Joaquin Valley. The alternatives developed in the SLDFRE EIS and other recently proposed drainage plans (refer to appendix A for details) differ from the strategies proposed by the San Joaquin Valley Drainage Program (1990a). The Bureau of Reclamation (USBR) in March 2007 signed a record of decision for an in-valley disposal option that would retire 194,000 acres of land, build 1,900 acres of evaporation ponds, and develop a treatment system to remove salt and selenium from drainwater. The recently proposed SLU Plans emphasize pumping drainage to the surface, storing approximately 33% in agricultural water re-use areas, treating selenium through biotechnology, enhancing the evaporation of water to concentrate salt, and identifying ultimate storage facilities for the remaining approximately 67% of waste selenium and salt. The treatment sequence of reuse, reverse osmosis, selenium bio-treatment, and enhanced solar evaporation is unprecedented and untested at the scale needed to meet plan requirements. All drainage management strategies that have been proposed seek to reduce the amount of drainage water produced. One approach is to reduce the amount of drainage per irrigated acre. From modeling simulations performed for the SLDFRE EIS of the Westlands Area of the SLU, theoretical minimums that can be achieved range from approximately 0.16 to 0.25 acre-feet per acre per year (AF/acre/year). Minimum production rates from the Northerly Area of the SLU are theorized as being much higher, approximately 0. 42 to 0.28 AF/acre/year. Rates shown in the SLU Plans for drained acres from the two areas combined are 0.5 AF/acre/year at the subsurface drain stage and 0.37 AF/acre/year after a series of on-farm and regional measures are instituted. Land retirement is a key strategy to reduce drainage because it can effectively reduce drainage to zero if all drainage-impaired lands are retired. Land retirement alternatives considered in the SLDFRE EIS differ for the two areas analyzed in the SLU. The Northerly Area is to retire a nominal 10,000 acres and Westlands is to retire up to 300,000 acres. The initial land retirement option recently put forth in the SLU Plans predicted drainage volume reductions that are consistent with 200,000 acres of land retirement, but only 100,000 acres of land retirement was proposed. Within the proposed area of drainage there are, for all practical purposes, unlimited reservoirs of selenium and salt stored within the aquifers and soils of the valley and upslope in the Coast Ranges. Salt imported in irrigation water is estimated to be at least 1.5 million tons per year for the Westlands and Northerly Areas (SJVDIP, 1998). Analysis of the land retirement alternatives presented in the SLDFRE EIS indicates that land retirement of a minimum of only 100,000 acres results in the annual pumping to the surface of 20,142 pounds of selenium or about a million pounds of selenium over a 50 year period. Retiring 200,000 acres results in an annual pumping of 14,750 pounds of selenium; and reti

In-situ Subsurface Soil Analyzer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ulmer, Chris

The Department of Energy’s (DOE’s) Terrestrial Ecosystem Science (TES) program is seeking improved sensor systems for monitoring hydro-biogeochemical processes in complex subsurface environments. The TES program is specifically interested in acquiring chemical and structural information regarding the type and nature of the hydration and redox states of subsurface chemical species. The technology should be able to perform on-site and real-time measurements to provide information not available using current sample acquisition and preservation processes. To address the needs of the DOE and the terrestrial science community, Physical Optics Corporation (POC) worked on the development of a new In-Situ Subsurface Soil Analyzermore » (ISSA) based on magnetic resonance technologies. Benchtop testing was performed to assess the feasibility of continuous wave electron pair resonance (CW-EPR) detection of chemical species in subsurface soil systems.« less

The Role of Subsurface Properties on Transport of Water and Trace Gases: 1D Simulations at Selected Mars Landing Sites.

NASA Astrophysics Data System (ADS)

Karatekin, O.; Gloesener, E.; Dehant, V. M. A.

2017-12-01

In this work, water ice stability and water vapour transport through porous martian subsurface are studied using a 1D diffusive model. The role of adsorption on water transfer in martian conditions is investigated as well as the range of parameters that have the largest effect on gas transport. In addition, adsorption kinetics is considered to examine its influence on the water vapor exchange between the subsurface and the atmosphere. As methane has been detected in the martian atmosphere, the subsurface model is then used to study methane diffusion in the CH4/CO2/H2O system from variable depths under the surface. The results of subsurface gas transport at selected locations/landing sites are shown and implications for present/future observations are discussed.

Wilcox group (Paleocene to Eocene) coals of the Sabine Uplift area, Texas and Louisiana

USGS Publications Warehouse

Hook, Robert W.; Warwick, Peter D.; SanFilipo, John R.; Warwick, Peter D.; Karlsen, Alexander K.; Merrill, Matthew D.; Valentine, Brett J.

2011-01-01

The Wilcox Group (Paleocene to Eocene) of the Sabine uplift, a structural arch in northeastern Texas and northwestern Louisiana (Figure 1), has lignite zones that approach subbituminous rank (see Chapter 4, this publication). These coals are among the highest quality resources known within the Gulf Coastal Plain because of their low ash yield and sulfur content. The surface expression of the Sabine uplift is defined by the contact between coal-bearing rocks of the Wilcox Group and overlying fluvial rocks of the Carrizo Sand, which is the basal unit of the Claiborne Group (Figures 2, 3). The Sabine uplift study area includes parts of Harrison, Marion, Nacogdoches, Panola, Rusk, Sabine, San Augustine, and Shelby Counties in Texas and Bossier, Caddo, De Soto, Natchitoches, Red River, and Sabine Parishes in Louisiana (Figure 1). Adjacent counties and parishes that include the subsurface Wilcox Group extend the regional Sabine uplift area. The Wilcox in the subsurface is underlain by the Midway Group (Figure 3), a mudstone-dominated marine sequence of Paleocene age. Quaternary alluvium and terrace deposits overlying the Wilcox Group at the surface are limited to areas of modern drainage.The total thickness of the Wilcox Group within the Sabine uplift area ranges from approximately 400 ft on outcrop to 2500 ft in subsurface (Kaiser, 1990). In a few places, the contact between the overlying Carrizo Sand and Wilcox Group is erosional, but in other places, the contact is gradational.

Vadose zone dynamics governing snowmelt infiltration and groundwater recharge in a seasonally frozen, semi-arid landscape

NASA Astrophysics Data System (ADS)

Mohammed, A.; LeBlanc, F.; Cey, E. E.; Hayashi, M.

2016-12-01

Snowmelt infiltration and vadose zone fluxes in seasonally frozen soils are strongly affected by meteorological and soil moisture dynamics occurring during the preceding fall and winter, and complex processes controlling soil hydraulic and thermal regimes. In order to predict their effects on hydrologic processes such as run-off generation, groundwater recharge and plant-water availability in cold regions, an improved understanding of the mechanisms governing coupled water and heat fluxes in the unsaturated zone is needed. Field and laboratory studies were conducted to investigate snowmelt infiltration and groundwater recharge through partially frozen ground over a range of climate and soil conditions in the Canadian Prairies. Meteorological and subsurface field measurements at three sites were combined with laboratory infiltration experiments on frozen undisturbed soil-columns to provide insights into the hydraulic and thermal processes governing water movement. Analysis reveals that antecedent moisture content and thermal profiles both strongly affect subsurface dynamics during infiltration of snowmelt. Preferential flow is also a critical parameter, as both thermal and hydraulic responses were observed at depth prior to complete ground thaw in the field; as well as drainage outflow from the frozen soil column experiments under certain conditions. Results indicate that both diffuse (matrix) and preferential (macropore) flow play significant roles in the infiltration and redistribution of snowmelt water under frozen soil conditions, and shallow groundwater recharge. This study highlights the critical subsurface factors and processes that control infiltration and groundwater recharge in these seasonally frozen landscapes.

Residues of endosulfan in surface and subsurface agricultural soil and its bioremediation.

PubMed

Odukkathil, Greeshma; Vasudevan, Namasivayam

2016-01-01

The persistence of many hydrophobic pesticides has been reported by various workers in various soil environments and its bioremediation is a major concern due to less bioavailability. In the present study, the pesticide residues in the surface and subsurface soil in an area of intense agricultural activity in Pakkam Village of Thiruvallur District, Tamilnadu, India, and its bioremediation using a novel bacterial consortium was investigated. Surface (0-15 cm) and subsurface soils (15-30 cm and 30-40 cm) were sampled, and pesticides in different layers of the soil were analyzed. Alpha endosulfan and beta endosulfan concentrations ranged from 1.42 to 3.4 mg/g and 1.28-3.1 mg/g in the surface soil, 0.6-1.4 mg/g and 0.3-0.6 mg/g in the subsurface soil (15-30 cm), and 0.9-1.5 mg/g and 0.34-1.3 mg/g in the subsurface soil (30-40 cm) respectively. Residues of other persistent pesticides were also detected in minor concentrations. These soil layers were subjected to bioremediation using a novel bacterial consortium under a simulated soil profile condition in a soil reactor. The complete removal of alpha and beta endosulfan was observed over 25 days. Residues of endosulfate were also detected during bioremediation, which was subsequently degraded on the 30th day. This study revealed the existence of endosulfan in the surface and subsurface soils and also proved that the removal of such a ubiquitous pesticide in the surface and subsurface environment can be achieved in the field by bioaugumenting a biosurfactant-producing bacterial consortium that degrades pesticides. Copyright © 2015 Elsevier Ltd. All rights reserved.

SUBSURFACE CHARACTERIZATION AND MONITORING TECHNIQUES: A DESK REFERENCE GUIDE - VOLUME II: THE VADOSE ZONE, FIELD SCREENING AND ANALYTICAL METHODS - APPENDICES C AND D

EPA Science Inventory

Many EPA programs, including those under the Resource Conservation and Recovery Act (RCRA) and the Comprehensive Response, Compensation, and Liability Act (CERCLA), require subsurface characterization and monitoring to detect ground-water contamination and provide data to deve...

High Frequency Electromagnetic Impedance Measurements for Characterization, Monitoring and Verification Efforts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Ki Ha; Becker, Alex; Framgos, William

1999-06-01

Non-invasive, high-resolution imaging of the shallow subsurface is needed for delineation of buried waste, detection of unexploded ordinance, verification and monitoring of containment structures, and other environmental applications. Electromagnetic measurements at frequencies between 1 and 100 MHz are important for such applications, because the induction number of many targets is small and the ability to determine the dielectric permittivity in addition to electrical conductivity of the subsurface is possible. Earlier workers were successful in developing systems for detecting anomalous areas, but no quantifiable information was accurately determined. For high-resolution imaging, accurate measurements are necessary so the field data can bemore » mapped into the space of the subsurface parameters. We are developing a non-invasive method for accurately imaging the electrical conductivity and dielectric permittivity of the shallow subsurface using the plane wave impedance approach. Electric and magnetic sensors are being tested in a known area against theoretical predictions, thereby insuring that the data collected with the high-frequency impedance (HFI) system will support high-resolution, multi-dimensional imaging techniques.« less

High-Frequency Electromagnetic Impedance Measurements for Characterization, Monitoring and Verification Efforts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Ki Ha; Becker, Alex; Tseng, Hung-Wen

2002-11-20

Non-invasive, high-resolution imaging of the shallow subsurface is needed for delineation of buried waste, detection of unexploded ordinance, verification and monitoring of containment structures, and other environmental applications. Electromagnetic (EM) measurements at frequencies between 1 and 100 MHz are important for such applications, because the induction number of many targets is small and the ability to determine the dielectric permittivity in addition to electrical conductivity of the subsurface is possible. Earlier workers were successful in developing systems for detecting anomalous areas, but no quantifiable information was accurately determined. For high-resolution imaging, accurate measurements are necessary so the field data canmore » be mapped into the space of the subsurface parameters. We are developing a non-invasive method for accurately mapping the electrical conductivity and dielectric permittivity of the shallow subsurface using the EM impedance approach (Frangos, 2001; Lee and Becker, 2001; Song et al., 2002). Electric and magnetic sensors are being tested in a known area against theoretical predictions, thereby insuring that the data collected with the high-frequency impedance (HFI) system will support high-resolution, multi-dimensional imaging techniques.« less

High-Frequency Electromagnetic Impedance Measurements for Characterization, Monitoring, and Verification Efforts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Ki Ha; Becker, Alex

2000-06-01

Non-invasive, high-resolution imaging of the shallow subsurface is needed for delineation of buried waste, detection of unexploded ordinance, verification and monitoring of containment structures, and other environmental applications. Electromagnetic measurements at frequencies between 1 and 100 MHz are important for such applications, because the induction number of many targets is small and the ability to determine the dielectric permittivity in addition to electrical conductivity of the subsurface is possible. Earlier workers were successful in developing systems for detecting anomalous areas, but no quantifiable information was accurately determined. For high-resolution imaging, accurate measurements are necessary so the field data can bemore » mapped into the space of the subsurface parameters. We are developing a non-invasive method for accurately imaging the electrical conductivity and dielectric permittivity of the shallow subsurface using the plane wave impedance approach (Song et al., 1997). Electric and magnetic sensors are being tested in a known area against theoretical predictions, thereby insuring that the data collected with the high-frequency impedance (HFI) system will support high-resolution, multi-dimensional imaging techniques.« less

High-Frequency Electromagnetic Impedance Measurements for Characterization, Monitoring and Verification Efforts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Ki Ha; Becker, Alex; Tseng, Hung-Wen

2001-06-10

Non-invasive, high-resolution imaging of the shallow subsurface is needed for delineation of buried waste, detection of unexploded ordinance, verification and monitoring of containment structures, and other environmental applications. Electromagnetic (EM) measurements at frequencies between 1 and 100 MHz are important for such applications, because the induction number of many targets is small and the ability to determine the dielectric permittivity in addition to electrical conductivity of the subsurface is possible. Earlier workers were successful in developing systems for detecting anomalous areas, but no quantifiable information was accurately determined. For high-resolution imaging, accurate measurements are necessary so the field data canmore » be mapped into the space of the subsurface parameters. We are developing a non-invasive method for accurately mapping the electrical conductivity and dielectric permittivity of the shallow subsurface using the EM impedance approach (Frangos, 2001; Lee and Becker, 2001). Electric and magnetic sensors are being tested in a known area against theoretical predictions, thereby insuring that the data collected with the high-frequency impedance (HFI) system will support high-resolution, multi-dimensional imaging techniques.« less

Subsurface Microsensors for Assisted Recertification of TPS (SmarTPS)

NASA Technical Reports Server (NTRS)

Pallix, Joan B.; Milos, Frank S.; Huestis, Dave; Arnold, James O. (Technical Monitor)

1999-01-01

Commercialization of a competitive reusable launch vehicle (RLV) is a primary goal for both NASA and the U.S. aerospace industry. To expedite achievement of this goal, the Bantam-X Technology Program is funding development of innovative technologies to lower costs for access to space. Ground operations is one area where significant cost reduction is required. For the Shuttle fleet, ground operations account for over 80% of the life cycle costs, and TPS recertification accounts for 27% of the operation costs ($4.5M per flight). Bantam Task TPS-7, Subsurface Microsensors for Assisted Recertification of TPS (SmarTPS), is a joint effort between NASA centers and industry partners to develop rapid remote detection and scanning technology for inspection of TPS and detection of subsurface defects. This short paper will provide a general overview of the SmarTPS concept.

Transbronchial drainage using endobronchial ultrasonography with guide sheath for lung abscess: A case report.

PubMed

Yaguchi, Daizo; Ichikawa, Motoshi; Inoue, Noriko; Kobayashi, Daisuke; Shizu, Masato; Imai, Naoyuki

2018-05-01

Lung abscess was previously treated surgically, but is now mainly treated with antibiotics and ideally with direct drainage, although postural drainage canalso be used. A chest abnormal shadow was detected in an 82-year-old man and he was referred to our department in November 2017. On chest computed tomography (CT), a low-density mass shadow was present in the left S8 segment. Lung abscess and lung cancer were considered as differential diagnoses, and treatment with sulbactam sodium/ampicillin sodium (SBT/ABPC) was first initiated for lung abscess. The etiologic agent could not be identified by sputum examination, and the abscess shadow remained. Lung abscess. Endobronchial ultrasonography with a guide sheath (EBUS-GS)-guided bronchoscopy was performed on hospital day 21 to diagnose the lesion, identify the etiologic agent if the lesion was a lung abscess, and attempt drainage. Vacuum aspiration performed in the guide sheath after the probe was placed within the lesion produced 4-5 ml of gray turbid pus, and the abscess was judged to have been drained. A subsequent pathological examination did not detect malignant cells. Klebsiella pneumoniae, Prevotella spp. was identified as the etiologic agent in bacteriological tests. Antibiotics were changed based on sensitivity test results, and drainage was similarly performed on hospital day 28. The shadow gradually improved and disappeared. Therefore, this procedure and treatment led to identification of the etiologic agent and helped with cure of the disease. Based on the basic principle of treatment for abscess using as much drainage as possible, EBUS-GS-guided transbronchial drainage may be considered to be a "new procedure" for lung abscess.

Transbronchial drainage using endobronchial ultrasonography with guide sheath for lung abscess

PubMed Central

Yaguchi, Daizo; Ichikawa, Motoshi; Inoue, Noriko; Kobayashi, Daisuke; Shizu, Masato; Imai, Naoyuki

2018-01-01

Abstract Rationale: Lung abscess was previously treated surgically, but is now mainly treated with antibiotics and ideally with direct drainage, although postural drainage canalso be used. Patient concerns: A chest abnormal shadow was detected in an 82-year-old man and he was referred to our department in November 2017. On chest computed tomography (CT), a low-density mass shadow was present in the left S8 segment. Lung abscess and lung cancer were considered as differential diagnoses, and treatment with sulbactam sodium/ampicillin sodium (SBT/ABPC) was first initiated for lung abscess. The etiologic agent could not be identified by sputum examination, and the abscess shadow remained. Diagnoses: Lung abscess. Interventions: Endobronchial ultrasonography with a guide sheath (EBUS-GS)-guided bronchoscopy was performed on hospital day 21 to diagnose the lesion, identify the etiologic agent if the lesion was a lung abscess, and attempt drainage. Vacuum aspiration performed in the guide sheath after the probe was placed within the lesion produced 4-5 ml of gray turbid pus, and the abscess was judged to have been drained. Outcomes: A subsequent pathological examination did not detect malignant cells. Klebsiella pneumoniae, Prevotella spp. was identified as the etiologic agent in bacteriological tests. Antibiotics were changed based on sensitivity test results, and drainage was similarly performed on hospital day 28. The shadow gradually improved and disappeared. Therefore, this procedure and treatment led to identification of the etiologic agent and helped with cure of the disease. Lessons: Based on the basic principle of treatment for abscess using as much drainage as possible, EBUS-GS-guided transbronchial drainage may be considered to be a “new procedure” for lung abscess. PMID:29768382

Enhancement of OCT images with vinyl polysiloxane (VPS)

NASA Astrophysics Data System (ADS)

Kang, Hobin; Darling, Cynthia L.; Fried, Daniel

2016-02-01

Several studies have shown that optical coherence tomography (OCT) can be used to measure the remaining enamel thickness and detect the location of subsurface lesions hidden under the sound enamel. Moreover studies have shown that high refractive index liquids can be used to improve the visibility of subsurface lesions in OCT images. In this study, we demonstrate that vinyl polysiloxane (VPS) impression materials which are routinely used in dentistry can be used to enhance the detection of dentinal lesions on tooth occlusal surfaces. Lesion presence was confirmed with polarized light microscopy and microradiography.

Fiber Optic Thermographic Detection of Flaws in Composites

NASA Technical Reports Server (NTRS)

Wu, Meng-Chou; Winfree, William P.

2009-01-01

Optical fibers with multiple Bragg gratings bonded to surfaces of structures were used for thermographic detection of subsurface defects in structures. The investigated structures included a 10-ply composite specimen with subsurface delaminations of various sizes and depths. Both during and following the application of a thermal heat flux to the surface, the individual Bragg grating sensors measured the temporal and spatial temperature variations. The obtained data were analyzed with thermal modeling to reveal particular characteristics of the interested areas. These results were found to be consistent with the simulation results.

Effects of 6 months of aging in water on hardness and surface roughness of two microhybrid dental composites.

PubMed

de Moraes, Rafael Ratto; Marimon, José Laurindo Machado; Schneider, Luis Felipe; Sinhoreti, Mário Alexandre Coelho; Correr-Sobrinho, Lourenço; Bueno, Márcia

2008-06-01

This study assessed the effect of 6 months of aging in water on surface roughness and surface/subsurface hardness of two microhybrid resin composites. Filtek Z250 and Charisma were tested. Cylindrical specimens were obtained and stored in distilled water for 24 hours or 6 months, at 37 degrees C. For Knoop hardness evaluation, the specimens were transversely wet-flattened, and indentations were made on surface and subsurface layers. Data were submitted to three-way ANOVA and Tukey's test (alpha < or = 0.05). Surface roughness baseline measurements were made at 24 hours and repeated after 6 months of storage. Data were submitted to repeated measures ANOVA and Tukey's test (alpha < or = 0.05). Surface hardness (KHN, kg/mm(2)) means (+/- standard deviation) ranged from 55 +/- 1 to 49 +/- 4 for Z250 and from 50 +/- 2 to 41 +/- 3 for Charisma, at 24 hours and 6 months, respectively. Subsurface means ranged from 58 +/- 2 to 61 +/- 3 for Z250 and from 50 +/- 1 to 54 +/- 2 for Charisma, at 24 hours and 6 months. For both composites, the aged specimens presented significantly softer surfaces (p < 0.01). For the subsurface hardness, alteration after storage was detected only for Charisma, which presented a significant rise in hardness (p < 0.01). Z250 presented significantly harder surface and subsurface layers in comparison with Charisma. Surface roughness (Ra, mum) means ranged from 0.07 +/- 0.00 to 0.07 +/- 0.01 for Z250 and from 0.06 +/- 0.01 to 0.07 +/- 0.01 for Charisma, at 24 hours and 6 months, respectively. For both composites, no significant roughness alteration was detected during the study (p= 0.386). The 6-month period of storage in water presented a significant softening effect on the surfaces of the composites, although no significant deleterious alteration was detected for the subsurface hardness. In addition, the storage period had no significant effect on the surface roughness of the materials.

Advancing Knowledge on Fugitive Natural Gas from Energy Resource Development at a Controlled Release Field Observatory

NASA Astrophysics Data System (ADS)

Cahill, A. G.; Chao, J.; Forde, O.; Prystupa, E.; Mayer, K. U.; Black, T. A.; Tannant, D. D.; Crowe, S.; Hallam, S.; Mayer, B.; Lauer, R. M.; van Geloven, C.; Welch, L. A.; Salas, C.; Levson, V.; Risk, D. A.; Beckie, R. D.

2017-12-01

Fugitive gas, comprised primarily of methane, can be unintentionally released from upstream oil and gas development either at surface from leaky infrastructure or in the subsurface through failure of energy well bore integrity. For the latter, defective cement seals around energy well casings may permit buoyant flow of natural gas from the deeper subsurface towards shallow aquifers, the ground surface and potentially into the atmosphere. Concerns associated with fugitive gas release at surface and in the subsurface include contributions to greenhouse gas emissions, subsurface migration leading to accumulation in nearby infrastructure and impacts to groundwater quality. Current knowledge of the extent of fugitive gas leakage including how to best detect and monitor over time, and particularly its migration and fate in the subsurface, is incomplete. We have established an experimental field observatory for evaluating fugitive gas leakage in an area of historic and ongoing hydrocarbon resource development within the Montney Resource Play of the Western Canadian Sedimentary Basin, British Columbia, Canada. Natural gas will be intentionally released at surface and up to 25 m below surface at various rates and durations. Resulting migration patterns and impacts will be evaluated through examination of the geology, hydrogeology, hydro-geochemistry, isotope geochemistry, hydro-geophysics, vadose zone and soil gas processes, microbiology, and atmospheric conditions. The use of unmanned aerial vehicles and remote sensors for monitoring and detection of methane will also be assessed for suitability as environmental monitoring tools. Here we outline the experimental design and describe initial research conducted to develop a detailed site conceptual model of the field observatory. Subsequently, results attained from pilot surface and sub-surface controlled natural gas releases conducted in late summer 2017 will be presented as well as results of numerical modelling conducted to plan methane release experiments in 2018 and onwards. This research will create knowledge which informs strategies to detect and monitor fugitive gas fluxes at the surface and in groundwater; as well as guide associated regulatory and technical policies.

Sub-surface defects detection of by using active thermography and advanced image edge detection

NASA Astrophysics Data System (ADS)

Tse, Peter W.; Wang, Gaochao

2017-05-01

Active or pulsed thermography is a popular non-destructive testing (NDT) tool for inspecting the integrity and anomaly of industrial equipment. One of the recent research trends in using active thermography is to automate the process in detecting hidden defects. As of today, human effort has still been using to adjust the temperature intensity of the thermo camera in order to visually observe the difference in cooling rates caused by a normal target as compared to that by a sub-surface crack exists inside the target. To avoid the tedious human-visual inspection and minimize human induced error, this paper reports the design of an automatic method that is capable of detecting subsurface defects. The method used the technique of active thermography, edge detection in machine vision and smart algorithm. An infrared thermo-camera was used to capture a series of temporal pictures after slightly heating up the inspected target by flash lamps. Then the Canny edge detector was employed to automatically extract the defect related images from the captured pictures. The captured temporal pictures were preprocessed by a packet of Canny edge detector and then a smart algorithm was used to reconstruct the whole sequences of image signals. During the processes, noise and irrelevant backgrounds exist in the pictures were removed. Consequently, the contrast of the edges of defective areas had been highlighted. The designed automatic method was verified by real pipe specimens that contains sub-surface cracks. After applying such smart method, the edges of cracks can be revealed visually without the need of using manual adjustment on the setting of thermo-camera. With the help of this automatic method, the tedious process in manually adjusting the colour contract and the pixel intensity in order to reveal defects can be avoided.

Analysis of landfills with historic airphotos

NASA Technical Reports Server (NTRS)

Erb, T. L.; Philipson, W. R.; Teng, W. L.; Liang, T.

1981-01-01

An investigation is conducted regarding the value of existing aerial photographs for waste management, including landfill monitoring. The value of historic aerial photographs for documenting landfill boundaries is shown in a graph in which the expansion of an active landfill is traced over a 40-year period. Historic aerial photographs can also be analyzed to obtain general or detailed land-use and land-cover information. In addition, the photographs provide information regarding other elements of the physical environment, including geology, soils, and surface and subsurface drainage. The value of historic photos is discussed, taking into account applications for inventory, assessing contamination/health hazards, planning corrective measures, planning waste collection and facilities, developing inactive landfills, and research concerning improved land-filling operations.

Herbicide use in the management of roadside vegetation, western Oregon, 1999-2000; effects on the water quality of nearby streams

USGS Publications Warehouse

Wood, Tamara M.

2001-05-07

Sulfometuron-methyl concentrations in runoff from the road shoulder ranged from 0.1 to 1 µg/L throughout the 3-month sampling period, and in the drainage ditch decreased from about 1 µg/L in October and November to about 0.2 µg/L in January. It was never detected in Bull Creek. Bromacil concentrations were similar to those of diuron. Glyphosate was never detected in fall samples from the road shoulder, the drainage ditch, or the stream.

Understanding Lymphatic Drainage Pathways of the Ovaries to Predict Sites for Sentinel Nodes in Ovarian Cancer

PubMed Central

Kleppe, Marjolein; Kraima, Anne C.; Kruitwagen, Roy F.P.M.; Van Gorp, Toon; Smit, Noeska N.; van Munsteren, Jacoba C.; DeRuiter, Marco C.

2015-01-01

Objective In ovarian cancer, detection of sentinel nodes is an upcoming procedure. Perioperative determination of the patient’s sentinel node(s) might prevent a radical lymphadenectomy and associated morbidity. It is essential to understand the lymphatic drainage pathways of the ovaries, which are surprisingly up till now poorly investigated, to predict the anatomical regions where sentinel nodes can be found. We aimed to describe the lymphatic drainage pathways of the human ovaries including their compartmental fascia borders. Methods A series of 3 human female fetuses and tissues samples from 1 human cadaveric specimen were studied. Immunohistochemical analysis was performed on paraffin-embedded transverse sections (8 or 10 μm) using antibodies against Lyve-1, S100, and α-smooth muscle actin to identify the lymphatic endothelium, Schwann, and smooth muscle cells, respectively. Three-dimensional reconstructions were created. Results Two major and 1 minor lymphatic drainage pathways from the ovaries were detected. One pathway drained via the proper ligament of the ovaries (ovarian ligament) toward the lymph nodes in the obturator fossa and the internal iliac artery. Another pathway drained the ovaries via the suspensory ligament (infundibulopelvic ligament) toward the para-aortic and paracaval lymph nodes. A third minor pathway drained the ovaries via the round ligament to the inguinal lymph nodes. Lymph vessels draining the fallopian tube all followed the lymphatic drainage pathways of the ovaries. Conclusions The lymphatic drainage pathways of the ovaries invariably run via the suspensory ligament (infundibulopelvic ligament) and the proper ligament of the ovaries (ovarian ligament), as well as through the round ligament of the uterus. Because ovarian cancer might spread lymphogenously via these routes, the sentinel node can be detected in the para-aortic and paracaval regions, obturator fossa and surrounding internal iliac arteries, and inguinal regions. These findings support the strategy of injecting tracers in both ovarian ligaments to identify sentinel nodes. PMID:26397066

Structural analyses of a rigid pavement overlaying a sub-surface void

NASA Astrophysics Data System (ADS)

Adam, Fatih Alperen

Pavement failures are very hazardous for public safety and serviceability. These failures in pavements are mainly caused by subsurface voids, cracks, and undulation at the slab-base interface. On the other hand, current structural analysis procedures for rigid pavement assume that the slab-base interface is perfectly planar and no imperfections exist in the sub-surface soil. This assumption would be violated if severe erosion were to occur due to inadequate drainage, thermal movements, and/or mechanical loading. Until now, the effect of erosion was only considered in the faulting performance model, but not with regards to transverse cracking at the mid-slab edge. In this research, the bottom up fatigue cracking potential, caused by the combined effects of wheel loading and a localized imperfection in the form of a void below the mid-slab edge, is studied. A robust stress and surface deflection analysis was also conducted to evaluate the influence of a sub-surface void on layer moduli back-calculation. Rehabilitative measures were considered, which included a study on overlay and fill remediation. A series regression of equations was proposed that provides a relationship between void size, layer moduli stiffness, and the overlay thickness required to reduce the stress to its original pre-void level. The effect of the void on 3D pavement crack propagation was also studied under a single axle load. The amplifications to the stress intensity was shown to be high but could be mitigated substantially if stiff material is used to fill the void and impede crack growth. The pavement system was modeled using the commercial finite element modeling program Abaqus RTM. More than 10,000 runs were executed to do the following analysis: stress analysis of subsurface voids, E-moduli back-calculation of base layer, pavement damage calculations of Beaumont, TX, overlay thickness estimations, and mode I crack analysis. The results indicate that the stress and stress intensity are, on average, amplified considerably: 80% and 150%, respectively, by the presence of the void and more severe in a bonded pavement system compared to an un-bonded system. The sub-surface void also significantly affects the layer moduli back-calculation. The equivalent moduli of the layers are reduced considerably when a sub-surface void is present. However, the results indicate the back-calculated moduli derived using surface deflection, and longitudinal stress basins did not yield equivalent layer moduli under mechanical loading; the back-calculated deflection-based moduli were larger than the stress-based moduli, leading to stress calculations that were lower than those found in the real system.

Estimating subsurface water volumes and transit times in Hokkaido river catchments, Japan, using high-accuracy tritium analysis

NASA Astrophysics Data System (ADS)

Gusyev, Maksym; Yamazaki, Yusuke; Morgenstern, Uwe; Stewart, Mike; Kashiwaya, Kazuhisa; Hirai, Yasuyuki; Kuribayashi, Daisuke; Sawano, Hisaya

2015-04-01

The goal of this study is to estimate subsurface water transit times and volumes in headwater catchments of Hokkaido, Japan, using the New Zealand high-accuracy tritium analysis technique. Transit time provides insights into the subsurface water storage and therefore provides a robust and quick approach to quantifying the subsurface groundwater volume. Our method is based on tritium measurements in river water. Tritium is a component of meteoric water, decays with a half-life of 12.32 years, and is inert in the subsurface after the water enters the groundwater system. Therefore, tritium is ideally suited for characterization of the catchment's responses and can provide information on mean water transit times up to 200 years. Only in recent years has it become possible to use tritium for dating of stream and river water, due to the fading impact of the bomb-tritium from thermo-nuclear weapons testing, and due to improved measurement accuracy for the extremely low natural tritium concentrations. Transit time of the water discharge is one of the most crucial parameters for understanding the response of catchments and estimating subsurface water volume. While many tritium transit time studies have been conducted in New Zealand, only a limited number of tritium studies have been conducted in Japan. In addition, the meteorological, orographic and geological conditions of Hokkaido Island are similar to those in parts of New Zealand, allowing for comparison between these regions. In 2014, three field trips were conducted in Hokkaido in June, July and October to sample river water at river gauging stations operated by the Ministry of Land, Infrastructure, Transport and Tourism (MLIT). These stations have altitudes between 36 m and 860 m MSL and drainage areas between 45 and 377 km2. Each sampled point is located upstream of MLIT dams, with hourly measurements of precipitation and river water levels enabling us to distinguish between the snow melt and baseflow contributions to the river discharge. For the June sampling, the tritium and stable isotope results indicate below normal river discharges with a strong contribution of snow melt at some sampling points, and relatively short groundwater transit times. The tritium concentration results are used to interpret mean transit times (MTTs) for each sampling point using a tritium input curve constructed from historical International Atomic Energy Agency and available Japanese data, and subsurface volumes are estimated from the MTTs and measured river discharges.

Global 30m Height Above the Nearest Drainage

NASA Astrophysics Data System (ADS)

Donchyts, Gennadii; Winsemius, Hessel; Schellekens, Jaap; Erickson, Tyler; Gao, Hongkai; Savenije, Hubert; van de Giesen, Nick

2016-04-01

Variability of the Earth surface is the primary characteristics affecting the flow of surface and subsurface water. Digital elevation models, usually represented as height maps above some well-defined vertical datum, are used a lot to compute hydrologic parameters such as local flow directions, drainage area, drainage network pattern, and many others. Usually, it requires a significant effort to derive these parameters at a global scale. One hydrological characteristic introduced in the last decade is Height Above the Nearest Drainage (HAND): a digital elevation model normalized using nearest drainage. This parameter has been shown to be useful for many hydrological and more general purpose applications, such as landscape hazard mapping, landform classification, remote sensing and rainfall-runoff modeling. One of the essential characteristics of HAND is its ability to capture heterogeneities in local environments, difficult to measure or model otherwise. While many applications of HAND were published in the academic literature, no studies analyze its variability on a global scale, especially, using higher resolution DEMs, such as the new, one arc-second (approximately 30m) resolution version of SRTM. In this work, we will present the first global version of HAND computed using a mosaic of two DEMS: 30m SRTM and Viewfinderpanorama DEM (90m). The lower resolution DEM was used to cover latitudes above 60 degrees north and below 56 degrees south where SRTM is not available. We compute HAND using the unmodified version of the input DEMs to ensure consistency with the original elevation model. We have parallelized processing by generating a homogenized, equal-area version of HydroBASINS catchments. The resulting catchment boundaries were used to perform processing using 30m resolution DEM. To compute HAND, a new version of D8 local drainage directions as well as flow accumulation were calculated. The latter was used to estimate river head by incorporating fixed and variable thresholding methods. The resulting HAND dataset was analyzed regarding its spatial variability and to assess the global distribution of the main landform types: valley, ecotone, slope, and plateau. The method used to compute HAND was implemented using PCRaster software, running on Google Compute Engine platform running under Ubuntu Linux. The Google Earth Engine was used to perform mosaicing and clipping of the original DEMs as well as to provide access to the final product. The effort took about three months of computing time on eight core CPU virtual machine.

Probability of detection of internal voids in structural ceramics using microfocus radiography

NASA Technical Reports Server (NTRS)

Baaklini, G. Y.; Roth, D. J.

1986-01-01

The reliability of microfocous X-radiography for detecting subsurface voids in structural ceramic test specimens was statistically evaluated. The microfocus system was operated in the projection mode using low X-ray photon energies (20 keV) and a 10 micro m focal spot. The statistics were developed for implanted subsurface voids in green and sintered silicon carbide and silicon nitride test specimens. These statistics were compared with previously-obtained statistics for implanted surface voids in similar specimens. Problems associated with void implantation are discussed. Statistical results are given as probability-of-detection curves at a 95 precent confidence level for voids ranging in size from 20 to 528 micro m in diameter.

Probability of detection of internal voids in structural ceramics using microfocus radiography

NASA Technical Reports Server (NTRS)

Baaklini, G. Y.; Roth, D. J.

1985-01-01

The reliability of microfocus x-radiography for detecting subsurface voids in structural ceramic test specimens was statistically evaluated. The microfocus system was operated in the projection mode using low X-ray photon energies (20 keV) and a 10 micro m focal spot. The statistics were developed for implanted subsurface voids in green and sintered silicon carbide and silicon nitride test specimens. These statistics were compared with previously-obtained statistics for implanted surface voids in similar specimens. Problems associated with void implantation are discussed. Statistical results are given as probability-of-detection curves at a 95 percent confidence level for voids ranging in size from 20 to 528 micro m in diameter.

DEVELOPMENT OF AN IN SITU THERMAL EXTRACTION DETECTION SYSTEM (TEDS) FOR RAPID, ACCURATE, QUANTITATIVE ANALYSIS OF ENVIRONMENTAL POLLUTANTS IN THE SUBSURFACE - PHASE I

EPA Science Inventory

Ion Signature Technology, Inc. (IST) will develop and market a collection and analysis system that will retrieve soil-bound pollutants as well as soluble and non-soluble contaminants from groundwater as the probe is pushed by cone penetrometry of Geoprobe into the subsurface. ...

Line-scan spatially offset Raman spectroscopy for inspecting subsurface food safety and quality

USDA-ARS?s Scientific Manuscript database

This paper presented a method for subsurface food inspection using a newly developed line-scan spatially offset Raman spectroscopy (SORS) technique. A 785 nm laser was used as a Raman excitation source. The line-shape SORS data was collected in a wavenumber range of 0–2815 cm-1 using a detection mod...

Magnetic perturbation inspection of inner bearing races

NASA Technical Reports Server (NTRS)

Barton, J. R.; Lankford, J.

1972-01-01

Approximately 100 inner race bearings were inspected nondestructively prior to endurance testing. Two of the bearings which failed during testing spalled at the sites of subsurface inclusions previously detected by using magnetic field perturbation. At other sites initially judged to be suspect, subsurface inclusion-nucleated cracking was observed. Inspection records and metallurgical sectioning results are presented and discussed.

Analysis of a PAH-degrading bacterial population in subsurface sediments on the Mid-Atlantic Ridge

NASA Astrophysics Data System (ADS)

Shao, Zongze; Cui, Zhisong; Dong, Chunming; Lai, Qiliang; Chen, Liang

2010-05-01

Little is known about the types and concentrations of polycyclic aromatic hydrocarbons (PAHs) existing in the deep-sea subsurface environment, which is believed to be cold, oligothrophic and of high static pressure. PAHs in the upper layers of the water column are unavoidably subjected to degradation while they are deposited to the sea floor and become embedded in the deep-sea sediment. In this report, a high concentration of PAHs was discovered in the sediment 2.7 m beneath the bottom surface at a water depth of 3962 m on the Mid-Atlantic Ridge (MAR). The total concentration of PAHs was 445 ng (g dry wt sediment) -1. Among the seven detected PAHs, the concentrations of phenanthrene (222 ng g -1) and fluorene (79 ng g -1) were relatively high. In addition, PAH-degrading bacteria were found within the sediments. As in a previously detected site on the MAR, in the PAH-enriched region of this site, a bacterium of the genus Cycloclasticus was found to be the predominant isolate detected by PCR-DGGE analysis. In addition, bacteria of the Halomonas, Marinobacter, Alcanivorax, Thalassospira and Maricaulis genera, were also included in the PAH-degrading community. In summary, a high concentration of PAHs was detected in the subsurface of the deep-sea sediment, and once again, the Cycloclasticus bacterium was confirmed to be a ubiquitous marine PAH degrader even in the subsurface marine environment. Considering the abundance of PAHs therein, biodegradation is thus thought to be inactive, probably because of the low temperature, limited oxygen and/or limited nutrients.

NONDESTRUCTIVE TESTING (NDT) TECHNIQUES TO DETECT CONTAINED SUBSURFACE HAZARDOUS WASTE

EPA Science Inventory

The project involves the detection of buried containers with NDT (remote-sensing) techniques. Seventeen techniques were considered and four were ultimately decided upon. They were: electromagnetic induction (EMI); metal detection (MD); magnetometer (MAG); and ground penetrating r...

Pesticides in streams in the Tar-Pamlico drainage basin, North Carolina, 1992-94

USGS Publications Warehouse

Woodside, Michael D.; Ruhl, Kelly E.

2001-01-01

From 1992 to 1994, 147 water samples were collected at 5 sites in the Tar-Pamlico drainage basin in North Carolina and analyzed for 46 herbicides, insecticides, and pesticide metabolites as part of the U.S. Geological Survey's National Water-Quality Assessment Program. Based on a common adjusted detection limit of 0.01 microgram per liter, the most frequently detected herbicides were metolachlor (84 percent), atrazine (78 percent), alachlor (72 percent), and prometon (57 percent). The insecticides detected most frequently were carbaryl (12 percent), carbofuran (7 percent), and diazinon (4 percent). Although the pesticides with the highest estimated uses generally were the compounds detected most frequently, there was not a strong correlation between estimated use and detection frequency. The development of statistical correlations between pesticide use and detection frequency was limited by the lack of information on pesticides commonly applied in urban and agricultural areas, such as prometon, chlorpyrifos, and diazinon, and the small number of basins included in this study. For example, prometon had the fourth highest detection frequency, but use information was not available. Nevertheless, the high detection frequency of prometon indicates that nonagricultural uses also contribute to pesticide levels in streams in the Tar-Pamlico drainage basin.Concentrations of the herbicides atrazine, alachlor, and trifluralin varied seasonally, with elevated concentrations generally occurring in the spring, during and immediately following application periods, and in the summer. Seasonal concentration patterns were less evident for prometon, diazinon, and chlorpyrifos. Alachlor is the only pesticide detected in concentrations that exceeded current (2000) drinking-water standards.

A New Sensitive GC-MS-based Method for Analysis of Dipicolinic Acid and Quantifying Bacterial Endospores in Deep Marine Subsurface Sediment

NASA Astrophysics Data System (ADS)

Fang, J.

2015-12-01

Marine sediments cover more than two-thirds of the Earth's surface and represent a major part of the deep biosphere. Microbial cells and microbial activity appear to be widespread in these sediments. Recently, we reported the isolation of gram-positive anaerobic spore-forming piezophilic bacteria and detection of bacterial endospores in marine subsurface sediment from the Shimokita coalbed, Japan. However, the modern molecular microbiological methods (e.g., DNA-based microbial detection techniques) cannot detect bacterial endospore, because endospores are impermeable and are not stained by fluorescence DNA dyes or by ribosomal RNA staining techniques such as catalysed reporter deposition fluorescence in situ hybridization. Thus, the total microbial cell abundance in the deep biosphere may has been globally underestimated. This emphasizes the need for a new cultivation independent approach for the quantification of bacterial endospores in the deep subsurface. Dipicolinic acid (DPA, pyridine-2,6-dicarboxylic acid) is a universal and specific component of bacterial endospores, representing 5-15wt% of the dry spore, and therefore is a useful indicator and quantifier of bacterial endospores and permits to estimate total spore numbers in the subsurface biosphere. We developed a sensitive analytical method to quantify DPA content in environmental samples using gas chromatography-mass spectrometry. The method is sensitive and more convenient in use than other traditional methods. We applied this method to analyzing sediment samples from the South China Sea (obtained from IODP Exp. 349) to determine the abundance of spore-forming bacteria in the deep marine subsurface sediment. Our results suggest that gram-positive, endospore-forming bacteria may be the "unseen majority" in the deep biosphere.

Determining the 3D Subsurface Density Structure of Taurus Littrow Valley Using Apollo 17 Gravity Data

NASA Technical Reports Server (NTRS)

Urbancic, N.; Ghent, R.; Stanley, S,; Johnson, C. L.; Carroll, K. A.; Hatch, D.; Williamson, M. C.; Garry, W. B.; Talwani, M.

2016-01-01

Surface gravity surveys can detect subsurface density variations that can reveal subsurface geologic features. In 1972, the Apollo 17 (A17) mission conducted the Traverse Gravimeter Experiment (TGE) using a gravimeter that measured the local gravity field near Taurus Littrow Valley (TLV), located on the south-eastern rim of the Serenitatis basin. TLV is hypothesized to be a basaltfilled radial graben resulting from the impact that formed Mare Serenitatis. It is bounded by both the North and South Massifs (NM and SM) as well as other smaller mountains to the East that are thought to be mainly composed of brecciated highland material. The TGE is the first and only successful gravity survey on the surface of the Moon. Other more recent satellite surveys, such as NASA's Gravity Recovery and Interior Laboratory (GRAIL) mission (2011- 2012), have produced the best global gravity field to date (approx. 13km resolution). However, these satellite surveys are not sensitive enough to detect fine-scale (<1km) lunar subsurface structures. This underscores the value of the data collected at the surface by A17. In the original analysis of the data a 2D forward-modelling approach was used to derive a thickness of the subsurface basalt layer of 1.0 km by assuming a simple flat-faced rectangular geometry and using densities derived from Apollo lunar samples. We are investigating whether modern 3D modelling techniques in combination with high-resolution topographical and image datasets can reveal additional fine-scale subsurface structure in TLV.

Relating sub-surface ice features to physiological stress in a climate sensitive mammal, the American pika (Ochotona princeps).

PubMed

Wilkening, Jennifer L; Ray, Chris; Varner, Johanna

2015-01-01

The American pika (Ochotona princeps) is considered a sentinel species for detecting ecological effects of climate change. Pikas are declining within a large portion of their range, and ongoing research suggests loss of sub-surface ice as a mechanism. However, no studies have demonstrated physiological responses of pikas to sub-surface ice features. Here we present the first analysis of physiological stress in pikas living in and adjacent to habitats underlain by ice. Fresh fecal samples were collected non-invasively from two adjacent sites in the Rocky Mountains (one with sub-surface ice and one without) and analyzed for glucocorticoid metabolites (GCM). We also measured sub-surface microclimates in each habitat. Results indicate lower GCM concentration in sites with sub-surface ice, suggesting that pikas are less stressed in favorable microclimates resulting from sub-surface ice features. GCM response was well predicted by habitat characteristics associated with sub-surface ice features, such as lower mean summer temperatures. These results suggest that pikas inhabiting areas without sub-surface ice features are experiencing higher levels of physiological stress and may be more susceptible to changing climates. Although post-deposition environmental effects can confound analyses based on fecal GCM, we found no evidence for such effects in this study. Sub-surface ice features are key to water cycling and storage and will likely represent an increasingly important component of water resources in a warming climate. Fecal samples collected from additional watersheds as part of current pika monitoring programs could be used to further characterize relationships between pika stress and sub-surface ice features.

[Interventional Radiology for Intra-Abdominal Abscess after Gastrectomy].

PubMed

Matsuura, Norihiro; Fujitani, Kazumasa; Kawada, Junji; Nishikawa, Kazuhiro; Nakatsuka, Rie; Miyazaki, Susumu; Danno, Katsuki; Motoori, Masaaki; Kubota, Masaru; Matsuda, Chu; Yoshida, Hiroshi; Iwase, Kazuhiro; Tanaka, Yasuhiro

2015-11-01

Approximately 20% of patients develop some complications after gastrectomy. These complications should be treated appropriately to achieve a positive outcome. The records of 6 patients with postoperative intra-abdominal abscesses treated with interventional radiology (IVR) were analyzed. The cause of abscess was anastomotic leakage in 4 patients and contaminated surgery after gastric perforation in 2 patients. Intra-abdominal abscesses were detected on postoperative day 12 (median), and an IVR-guided drainage tube was inserted with a median interval of 1 day. The drainage tube was kept in place for 26 days (median), and patients were discharged 6.5 days (median) after drainage tube removal. No patients were converted to open surgery. Early IVR-guided drainage was essential and effective for intra-abdominal abscess treatment after gastrectomy.

Long term drainage alters plant biodiversity and soil C- and N-storage

NASA Astrophysics Data System (ADS)

Wolf, K.; Bol, R.; Dungait, J. A. J.; Dixon, L.; Dhanoa, D.; Beaumont, D.; Wiesenberg, G. L. B.

2012-04-01

Moisture and slope position can have a strong influence on soil properties and plant communities. In a long term permanent grassland experiment, sub-surface drainage was introduced in 1982 on some plots of Rowden Moor at North Wyke (SW UK). The soil is a Stagnic vertic Cambisol with a dense clay layer at shallow depth. After drainage the plant community had shifted from a Lolium perenne dominated grassland with patches of Juncus sp. towards a typical grassland plant community dominated by Lolium perenne and Trifolium sp. In addition, soil carbon and nitrogen concentrations significantly decreased. This is related to a smaller contribution of plant-derived organic matter to soil due to the change in plant community structure, and the enhanced mineralization of soil organic matter (SOM) under lower soil moisture. However, for C:N ratios neither plants nor soil did reveal any drainage related change arguing for an identical degradability of plant and soil organic matter. Furthermore the δ13C values tend to get more negative in soil, which could be related to the changing plant community. For δ15N no changes were observed, which was surprising as increase δ15N values were expected due to the increase in legumes on the drained plot. Changes in the chemical composition of SOM were also examined using compositional changes of soil n-alkanes. A shift in the alkane abundance occurs from the upper part of the slope (dominated by n-C31), to the bottom parts (n-C29 enriched). The carbon preference index and average chain length of alkanes correlated between undrained and drained plots and decreased down slope. Similarly, several alkane ratios like n-C27/n-C31 declined, due to the enhanced mineralization. Hence, the molecular pattern changed on the one hand due to changing contribution of plant derived organic matter and on the other hand because of changing preservation of organic matter in soil. The study showed that drainage has a long term effect on the plant community leading to depletion in C- and N-contents and a change in the chemical composition of SOM.

Mobile geophysical study of peat deposits in Fuhrberger Field, Germany

NASA Astrophysics Data System (ADS)

Wunderlich, T.; Petersen, H.; Hagrey, S. A. al; Rabbel, W.

2012-04-01

In the water protection area of Fuhrberger Field, north of Hanover, geophysical techniques were applied to study the stakeholder problem of the source detection for nitrate accumulations in the ground water. We used our mobile multisensor platform to conduct measurements using Ground Penetrating Radar (GPR, 200 MHz antenna) and Electromagnetic Induction (EMI, EM31). This aims to study the subsurface occurrences of peat deposits (surplus of organic carbon) supposed to be a source of nitrate emissions due to the aeration and the drawdown of groundwater levels (e.g. by pumping, drainage etc.). Resulting EMI and GPR signals show high data quality. Measured apparent electrical conductivity shows very low values (<10 mS/m) due to the mainly sandy subsurface. For this medium, both methods are expected to penetrate down to 3-5 m depth. GPR radargrams, time slices of GPR reflection energy and EMI apparent electrical conductivities are plotted on aerial photographs and compared to each other's and with vegetation intensity. We could separate areas characterized by low reflection energy and high conductivity, and vice versa. Briefly, organic rich sediments such as peats are assumed to have a relative high conductivity and thus low GPR reflectivity. Some areas of local conductivity increase correspond to a deep reflection interface (as seen in the radargrams), which even vanishes due to the high attenuation caused by the high conductivity. This implies that the upper layer is more conductive than the lower layer. Several local areas with these characteristics are found at the study sites. We recommend shallow drillings at representative points to deliver the necessary confirmation with ground truth information. Acknowledgments: iSOIL (Interactions between soil related sciences - Linking geophysics, soil science and digital soil mapping) is a Collaborative Project (Grant Agreement number 211386) co-funded by the Research DG of the European Commission within the RTD activities of the FP7 Thematic Priority Environment.

Agricultural conservation planning framework: 1. Developing multipractice watershed planning scenarios and assessing nutrient reduction potential.

PubMed

Tomer, M D; Porter, S A; Boomer, K M B; James, D E; Kostel, J A; Helmers, M J; Isenhart, T M; McLellan, E

2015-05-01

Spatial data on soils, land use, and topography, combined with knowledge of conservation effectiveness, can be used to identify alternatives to reduce nutrient discharge from small (hydrologic unit code [HUC]12) watersheds. Databases comprising soil attributes, agricultural land use, and light detection and ranging-derived elevation models were developed for two glaciated midwestern HUC12 watersheds: Iowa's Beaver Creek watershed has an older dissected landscape, and Lime Creek in Illinois is young and less dissected. Subsurface drainage is common in both watersheds. We identified locations for conservation practices, including in-field practices (grassed waterways), edge-of-field practices (nutrient-removal wetlands, saturated buffers), and drainage-water management, by applying terrain analyses, geographic criteria, and cross-classifications to field- and watershed-scale geographic data. Cover crops were randomly distributed to fields without geographic prioritization. A set of alternative planning scenarios was developed to represent a variety of extents of implementation among these practices. The scenarios were assessed for nutrient reduction potential using a spreadsheet approach to calculate the average nutrient-removal efficiency required among the practices included in each scenario to achieve a 40% NO-N reduction. Results were evaluated in the context of the Iowa Nutrient Reduction Strategy, which reviewed nutrient-removal efficiencies of practices and established the 40% NO-N reduction as Iowa's target for Gulf of Mexico hypoxia mitigation by agriculture. In both test watersheds, planning scenarios that could potentially achieve the targeted NO-N reduction but remove <5% of cropland from production were identified. Cover crops and nutrient removal wetlands were common to these scenarios. This approach provides an interim technology to assist local watershed planning and could provide planning scenarios to evaluate using watershed simulation models. A set of ArcGIS tools is being released to enable transfer of this mapping technology. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Microbial acceleration of aerobic pyrite oxidation at circumneutral pH.

PubMed

Percak-Dennett, E; He, S; Converse, B; Konishi, H; Xu, H; Corcoran, A; Noguera, D; Chan, C; Bhattacharyya, A; Borch, T; Boyd, E; Roden, E E

2017-09-01

Pyrite (FeS 2 ) is the most abundant sulfide mineral on Earth and represents a significant reservoir of reduced iron and sulfur both today and in the geologic past. In modern environments, oxidative transformations of pyrite and other metal sulfides play a key role in terrestrial element partitioning with broad impacts to contaminant mobility and the formation of acid mine drainage systems. Although the role of aerobic micro-organisms in pyrite oxidation under acidic-pH conditions is well known, to date there is very little known about the capacity for aerobic micro-organisms to oxidize pyrite at circumneutral pH. Here, we describe two enrichment cultures, obtained from pyrite-bearing subsurface sediments, that were capable of sustained cell growth linked to pyrite oxidation and sulfate generation at neutral pH. The cultures were dominated by two Rhizobiales species (Bradyrhizobium sp. and Mesorhizobium sp.) and a Ralstonia species. Shotgun metagenomic sequencing and genome reconstruction indicated the presence of Fe and S oxidation pathways in these organisms, and the presence of a complete Calvin-Benson-Bassham CO 2 fixation system in the Bradyrhizobium sp. Oxidation of pyrite resulted in thin (30-50 nm) coatings of amorphous Fe(III) oxide on the pyrite surface, with no other secondary Fe or S phases detected by electron microscopy or X-ray absorption spectroscopy. Rates of microbial pyrite oxidation were approximately one order of magnitude higher than abiotic rates. These results demonstrate the ability of aerobic microbial activity to accelerate pyrite oxidation and expand the potential contribution of micro-organisms to continental sulfide mineral weathering around the time of the Great Oxidation Event to include neutral-pH environments. In addition, our findings have direct implications for the geochemistry of modern sedimentary environments, including stimulation of the early stages of acid mine drainage formation and mobilization of pyrite-associated metals. © 2017 John Wiley & Sons Ltd.

A high frequency electromagnetic impedance imaging system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tseng, Hung-Wen; Lee, Ki Ha; Becker, Alex

2003-01-15

Non-invasive, high resolution geophysical mapping of the shallow subsurface is necessary for delineation of buried hazardous wastes, detecting unexploded ordinance, verifying and monitoring of containment or moisture contents, and other environmental applications. Electromagnetic (EM) techniques can be used for this purpose since electrical conductivity and dielectric permittivity are representative of the subsurface media. Measurements in the EM frequency band between 1 and 100 MHz are very important for such applications, because the induction number of many targets is small and the ability to determine the subsurface distribution of both electrical properties is required. Earlier workers were successful in developing systemsmore » for detecting anomalous areas, but quantitative interpretation of the data was difficult. Accurate measurements are necessary, but difficult to achieve for high-resolution imaging of the subsurface. We are developing a broadband non-invasive method for accurately mapping the electrical conductivity and dielectric permittivity of the shallow subsurface using an EM impedance approach similar to the MT exploration technique. Electric and magnetic sensors were tested to ensure that stray EM scattering is minimized and the quality of the data collected with the high-frequency impedance (HFI) system is good enough to allow high-resolution, multi-dimensional imaging of hidden targets. Additional efforts are being made to modify and further develop existing sensors and transmitters to improve the imaging capability and data acquisition efficiency.« less

Water resources of the Cook Inlet Basin, Alaska

USGS Publications Warehouse

Freethey, Geoffrey W.; Scully, David R.

1980-01-01

Ground-water and surface-water systems of Cook Inlet basin, Alaska, are analyzed. Geologic and topographic features that control the movement and regional availability of ground water are explained and illustrated. Five aquifer systems beneath the most populous areas are described. Estimates of ground-water yield were determined for the region by using ground-water data for the populated areas and by extrapolating known subsurface conditions and interpreting subsurface conditions from surficial features in the other areas. Area maps of generalized geology, Quaternary sediment thickness, and general availability of ground water are shown. Surface-water resources are summarized by describing how basin characteristics affect the discharge in streams. Seasonal trend of streamflow for three types of streams is described. Regression equations for 4 streamflow characteristics (annual, monthly minimum, and maximum discharge) were obtained by using gaging station streamflow characteristics and 10 basin characteristics. In the 24 regression equations presented, drainage area is the most significant basin characteristic, but 5 others are used. Maps of mean annual unit runoff and minimum unit yield for 7 consecutive days with a recurrence interval of 10 years are shown. Historic discharge data at gaging stations is tabulated and representative low-flow and flood-flow frequency curves are shown. (USGS)

Design and routing of storm flows in an urbanized watershed without surface streams

NASA Astrophysics Data System (ADS)

Schaad, David E.; Farley, Jon; Haynes, Criss

2009-09-01

SummaryIn the karst geologic setting of Greenbrier County, West Virginia, USA, the drainage network in the watersheds do not support surface streams, but depend entirely on sinkholes, solution cavities, or injection wells as discharge points for accumulated storm water. By providing a systematic framework for designing and routing storms in this geologic setting, functioning retention and attenuation structures have been developed which are protective of water quality while still safely discharging storm water in a controlled manner to the subsurface. This article provides a rationale for the design methodology and then examines the successful implementation of an attenuation and storm water retention design to manage the surface discharges for an entire watershed. By examining the pre-development flows and evaluating future land use patterns (i.e., installation of impermeable surfaces over large areas), as well as sinkhole conveyance capabilities, it was necessary to examine alternative disposal options for collected storm water as well as devise a basin-wide management strategy to coordinate future development of the watershed. Additionally, innovative water quality measures were implemented to help prevent contamination from preferentially infiltrating into the subsurface as a result of these land development activities.

An optimization model to design and manage subsurface drip irrigation system for alfalfa

NASA Astrophysics Data System (ADS)

Kandelous, M.; Kamai, T.; Vrugt, J. A.; Simunek, J.; Hanson, B.; Hopmans, J. W.

2010-12-01

Subsurface drip irrigation (SDI) is one of the most efficient and cost-effective methods for watering alfalfa plants. Lateral installation depth and distance, emitter discharge, and irrigation time and frequency of SDI, in addition to soil and climatic conditions affect alfalfa’s root water uptake and yield. Here we use a multi-objective optimization approach to find optimal SDI strategies. Our approach uses the AMALGAM evolutionary search method, in combination with the HYDRUS-2D unsaturated flow model to maximize water uptake by alfalfa’s plant roots, and minimize loss of irrigation and drainage water to the atmosphere or groundwater. We use a variety of different objective functions to analyze SDI. These criteria include the lateral installation depth and distance, the lateral discharge, irrigation duration, and irrigation frequency. Our framework includes explicit recognition of the soil moisture status during the simulation period to make sure that the top soil is dry for harvesting during the growing season. Initial results show a wide spectrum of optimized SDI strategies for different root distributions, soil textures and climate conditions. The developed tool should be useful in helping farmers optimize their irrigation strategy and design.

Clinical outcomes of percutaneous drainage of breast fluid collections following mastectomy with expander-based breast reconstruction

PubMed Central

2015-01-01

PURPOSE To determine clinical outcomes of patients who underwent imaging-guided percutaneous drainage of breast fluid collections following mastectomy and breast reconstruction. MATERIAL AND METHODS Retrospective review included all consecutive patients who underwent percutaneous drainage of fluid collections following mastectomy with tissue expander-based reconstruction between January 2007 and September 2012. A total of 879 mastectomies (563 patients) with expander-based breast reconstruction were performed during this period. 28 patients (5%) developed fluid collections, which led to 30 imaging-guided percutaneous drainage procedures. The median follow up time was 533 days. Patient characteristics, surgical technique, microbiology analysis, and clinical outcomes were reviewed. RESULTS The mean age was 51.5 years (range 30.9 to 69.4 years) and the median time between breast reconstruction and drainage was 35 days (range 4 to 235 days). Erythema and swelling were the most common presenting symptoms. The median volume of fluid evacuated at the time of drain placement was 70 mL. Drains were left in place for a median 14 days (range 6 to 34 days). Microorganisms were detected in the fluid in 12 of 30 drainage procedures, with Staphylococcus aureus being the most common microorganism. No further intervention was needed in 21 of 30 drainage procedures (70%). However, surgical intervention (removal of expanders) was needed following 6 (20%) drainages, and additional percutaneous drainage procedures were performed following 3 (10%) drainages. CONCLUSION Percutaneous drainage is an effective means of treating post operative fluid collections after expander-based breast reconstruction and can obviate the need for repeat surgery in most cases. PMID:23810309

Deep subsurface drip irrigation using coal-bed sodic water: part I. water and solute movement

USGS Publications Warehouse

Bern, Carleton R.; Breit, George N.; Healy, Richard W.; Zupancic, John W.; Hammack, Richard

2013-01-01

Water co-produced with coal-bed methane (CBM) in the semi-arid Powder River Basin of Wyoming and Montana commonly has relatively low salinity and high sodium adsorption ratios that can degrade soil permeability where used for irrigation. Nevertheless, a desire to derive beneficial use from the water and a need to dispose of large volumes of it have motivated the design of a deep subsurface drip irrigation (SDI) system capable of utilizing that water. Drip tubing is buried 92 cm deep and irrigates at a relatively constant rate year-round, while evapotranspiration by the alfalfa and grass crops grown is seasonal. We use field data from two sites and computer simulations of unsaturated flow to understand water and solute movements in the SDI fields. Combined irrigation and precipitation exceed potential evapotranspiration by 300-480 mm annually. Initially, excess water contributes to increased storage in the unsaturated zone, and then drainage causes cyclical rises in the water table beneath the fields. Native chloride and nitrate below 200 cm depth are leached by the drainage. Some CBM water moves upward from the drip tubing, drawn by drier conditions above. Chloride from CBM water accumulates there as root uptake removes the water. Year over year accumulations indicated by computer simulations illustrate that infiltration of precipitation water from the surface only partially leaches such accumulations away. Field data show that 7% and 27% of added chloride has accumulated above the drip tubing in an alfalfa and grass field, respectively, following 6 years of irrigation. Maximum chloride concentrations in the alfalfa field are around 45 cm depth but reach the surface in parts of the grass field, illustrating differences driven by crop physiology. Deep SDI offers a means of utilizing marginal quality irrigation waters and managing the accumulation of their associated solutes in the crop rooting zone.

Dissolved constituents including selenium in waters in the vicinity of Kesterson National Wildlife Refuge and the west grassland, Fresno and Merced Counties, California

USGS Publications Warehouse

Presser, T.S.; Barnes, Ivan

1985-01-01

Analyses were made for dissolved constituents including selenium (Se) in waters associated with subsurface agricultural drainage from the western San Joaquin Valley of California. In the vicinity of Kesterson National Wildlife Refuge and the Grassland wetlands area Se was found to be mobilized in water. As a consequence of this mobility and bioaccumulation in the aquatic food chain, Se occurred in waterfowl at levels toxic enough to cause deformities and deaths. Se concentrations in sumps that collect subsurface agricultural drainage water and inflows to drains sampled, ultimately leading into Kesterson National Wildlife Refuge and the Grassland, ranged from 84 to 4200 microgram/L (ug/L) Se. Levels of Se were reduced in the San Luis Drain flowing into Kesterson National Wildlife Refute to approximately 300 ug/L Se and in three of the drains sampled flowing into the Grassland to approximately 50 ug/L Se. Serious effects on water fowl habitat were caused by both these levels. Se contents of algal mats and salt crusts from evaporation ponds of the San Luis Drain contained up to parts per million Se. Total ecosystem assessment of Se may be necessary for the evaluation of the toxicity of Se to the environment. No other trace element reported exceeded the various criteria for water at the level of magnitude of Se. Other dissolved constituents and the isotopic ratios of oxygen and hydrogen were analyzed to elucidate water types, reaction states of the aqueous solution with respect to minerals, and the origin of mixed waters. These data will be used later to evaluate the geologic source of Se. Methods used for collection and analysis are described and documented. Hydrologic effects were found to be complex. Preliminary indications from wells are also given. A historical sequence is adhered to and other data from the study area which serve as a guide to the toxicity of Se are included. (Author 's abstract)

Surface-water and karst groundwater interactions and streamflow-response simulations of the karst-influenced upper Lost River watershed, Orange County, Indiana

USGS Publications Warehouse

Bayless, E. Randall; Cinotto, Peter J.; Ulery, Randy L.; Taylor, Charles J.; McCombs, Gregory K.; Kim, Moon H.; Nelson, Hugh L.

2014-01-01

The U.S. Geological Survey (USGS), in cooperation with the U.S. Army Corps of Engineers (USACE) and the Indiana Office of Community and Rural Affairs (OCRA), conducted a study of the upper Lost River watershed in Orange County, Indiana, from 2012 to 2013. Streamflow and groundwater data were collected at 10 data-collection sites from at least October 2012 until April 2013, and a preliminary Water Availability Tool for Environmental Resources (WATER)-TOPMODEL based hydrologic model was created to increase understanding of the complex, karstic hydraulic and hydrologic system present in the upper Lost River watershed, Orange County, Ind. Statistical assessment of the optimized hydrologic-model results were promising and returned correlation coefficients for simulated and measured stream discharge of 0.58 and 0.60 and Nash-Sutcliffe efficiency values of 0.56 and 0.39 for USGS streamflow-gaging stations 03373530 (Lost River near Leipsic, Ind.), and 03373560 (Lost River near Prospect, Ind.), respectively. Additional information to refine drainage divides is needed before applying the model to the entire karst region of south-central Indiana. Surface-water and groundwater data were used to tentatively quantify the complex hydrologic processes taking place within the watershed and provide increased understanding for future modeling and management applications. The data indicate that during wet-weather periods and after certain intense storms, the hydraulic capacity of swallow holes and subsurface conduits is overwhelmed with excess water that flows onto the surface in dry-bed relic stream channels and karst paleovalleys. Analysis of discharge data collected at USGS streamflow-gaging station 03373550 (Orangeville Rise, at Orangeville, Ind.), and other ancillary data-collection sites in the watershed, indicate that a bounding condition is likely present, and drainage from the underlying karst conduit system is potentially limited to near 200 cubic feet per second. This information will direct future studies and assist managers in understanding when the subsurface conduits may become overwhelmed.

The impact of pre-restoration land-use and disturbance on sediment structure, hydrology and the sediment geochemical environment in restored saltmarshes.

PubMed

Spencer, Kate L; Carr, Simon J; Diggens, Lucy M; Tempest, James A; Morris, Michelle A; Harvey, Gemma L

2017-06-01

Saltmarshes are being lost or degraded as a result of human activity resulting in loss of critical ecosystem services including the provision of wild species diversity, water quality regulation and flood regulation. To compensate, saltmarshes are being restored or re-created, usually driven by legislative requirements for increased habitat diversity, flood regulation and sustainable coastal defense. Yet, there is increasing evidence that restoration may not deliver anticipated ecosystem services; this is frequently attributed to poor drainage and sediment anoxia. However, physical sediment characteristics, hydrology and the sediment geochemical environment are rarely examined in restoration schemes, despite such factors being critical for plant succession. This study presents the novel integration of 3D-computed X-ray microtomography to quantify sediment structure and porosity, with water level and geochemical data to understand the impact of pre-restoration land use and disturbance on the structure and functioning of restored saltmarshes. The study combines a broad-scale investigation of physical sediment characteristics in nine de-embanked saltmarshes across SE England, with an intensive study at one site examining water levels, sediment structure and the sediment geochemical environment. De-embankment does not restore the hydrological regime, or the physical/chemical framework in the saltmarshes and evidence of disturbance includes a reduction in microporosity, pore connectivity and water storage capacity, a lack of connectivity between the sub-surface environment and overlying floodwaters, and impeded sub-surface water flow and drainage. This has significant consequences for the sediment geochemical environment. This disturbance is evident for at least two decades following restoration and is likely to be irreversible. It has important implications for plant establishment in particular, ecosystem services including flood regulation, nutrient cycling and wild species diversity and for future restoration design. Copyright © 2016 Elsevier B.V. All rights reserved.

A Microfluidics Study to Quantify the Impact of Microfracture Properties on Two-Phase Flow in Tight Rocks

NASA Astrophysics Data System (ADS)

Mehmani, A.; Kelly, S. A.; Torres-Verdin, C.; Balhoff, M.

2017-12-01

Microfluidics provides the opportunity for controlled experiments of immiscible fluid dynamics in quasi two-dimensional permeable media and allows their direct observation. We leverage microfluidics to investigate the impact of microfracture properties on water imbibition and drainage in a porous matrix. In the context of this work, microfractures are defined as apertures or preferential flow paths formed along planes of weakness, such as between two different rock fabrics. Patterns of pseudo-microfractures with orientations from parallel and perpendicular to fluid flow as well as variations in their connectivity were fabricated in glass micromodels; surface roughness of the micromodels was also varied utilizing a new method. Light microscopy and image analysis were used to quantify transient front advancement and trapped non-wetting phase saturation during imbibition as well as residual wetting phase saturation and its spatial distribution following drainage. Our experiments enable the assessment of quantitative relationships between fluid invasion rate and residual phase distributions as functions of microfracture network properties. Ultimately, the wide variety of microfluidic experiments performed in this study provide valuable insight into two-phase fluid dynamics in microfracture/matrix networks, the extent of fracture fluid invasion, and the saturation of trapped phases. In reservoir description, the geometries of subsurface fractures are often difficult to ascertain, but the distribution of rock types in a zone, from highly laminated to homogenous, can be reliably assessed with core data and well logs. Assuming that microcracks are functions of lamination planes (thin beds), then a priori predictions of the effect of microcracks on two-phase fluid flow across various geological conditions can possibly be upscaled via effective lamination properties. Such upscaling can significantly reduce the uncertainties associated with subsurface operations, including reservoir production, carbon storage and sequestration, and hazardous waste sequestration. A reliable prediction of capillary trapping, for instance, can determine the fracture fluid saturation subsequent to hydraulic fracturing of unconventional formations or the efficacy of water flooding in fractured reservoirs.

Progress in the application of landform analysis in studies of semiarid erosion

USGS Publications Warehouse

Schumm, Stanley Alfred; Hadley, R.F.

1961-01-01

The analysis of topographic and hydrologic data gathered during studies of erosion in semiarid areas of Western United States show the following relation: (a) Mean annual sediment yield from small drainage basins is related to a ratio of basin relief to length; (b) mean annual runoff from small drainage basins is related to drainage density; (c) mean annual sediment yield per unit area decreases with increase in drainage area; (d) the form of some convex hill slopes is related to surficial creep; (e) asymmetry of drainage basins, including differences in hill-slope erosion and drainage density, is related to microclimatic variations on slopes of diverse exposure; .(f) the cutting of discontinuous gullies is closely related to steepening by deposition of the semiarid valley floor; (g) aggradation in ephemeral streams seems to be most prevalent in reaches where the ratio of contributing drainage area to channel length is relatively small; and (h) streamchannel shape, expressed as a width-depth ratio, is related to the percentage of silt-clay in bed and bank alluvium. The above relations cannot be detected without measurement of terrain characteristics. They further indicate the importance of quantitative terrain analysis in studies of erosion.

Subsurface In Situ Elemental Composition Measurements with PING

NASA Technical Reports Server (NTRS)

Parsons, Ann; McClanahan, Timothy; Bodnarik, Julia; Evans, Larry; Nowicki, Suzanne; Schweitzer, Jeffrey; Starr, Richard

2013-01-01

This paper describes the Probing In situ with Neutron and Gamma rays (PING) instrument, that can measure the subsurface elemental composition in situ for any rocky body in the solar system without the need for digging into the surface. PING consists of a Pulsed Neutron Generator (PNG), a gamma ray spectrometer and neutron detectors. Subsurface elements are stimulated by high-energy neutrons to emit gamma rays at characteristic energies. This paper will show how the detection of these gamma rays results in a measurement of elemental composition. Examples of the basalt to granite ratios for aluminum and silicon abundance are provided.

Surface and subsurface sensor performance in acoustically detecting western drywood termites in naturally infested boards.

Treesearch

V.R. Lewis; A.B. Power; M.I. Haverty

2004-01-01

Field-collected boards showing visual signs of damage by the western drywood termite, Incisitermes minor, were searched with a portable acoustic emission (AE) device. Depending on cross-sectional size, boards were either searched with a flat sensor that was hot-melt-glued to the wood surface or a subsurface sensor that wasthreaded 20 mm into the...

Subsurface ice and brine sampling using an ultrasonic/sonic gopher for life detection and characterization in the McMurdo Dry Valleys

NASA Technical Reports Server (NTRS)

Bar-Cohen, Y.; Sherrit, S.; Chang, Z.; Wessel, L.; Bao, X.; Doran, P. T.; Fritsen, C. H.; Kenig, F.; McKay, C. P.; Murray, A.;

Role of air on local water retention behavior in the shallow heterogeneous vadose zone

NASA Astrophysics Data System (ADS)

Sakaki, T.; Limsuwat, A.; Illangasekare, T. H.

2009-12-01

In the presence of a subsurface source, air flowing through the unsaturated soil can transport toxic vapor into subsurface structures due to pressure gradients created by, e.g., a pressure drop within the building. Development of dynamic air pathways in the subsurface are largely controlled by the geological heterogeneity and the spatial and temporal distribution of soil moisture. To better understand how these air pathways are developed, it is crucial to know how water is retained in heterogeneous medium at spatial resolutions that are finer than those adopted in typical hydrologic and soil physics applications. Although methods for soil water pressure measurement can be readily found in literature, a technique for measuring “air pressure” in wet soil is not well-established or documented. Hydrophobic porous ceramic cups have been used to measure non-wetting NAPL phase pressure in two-phase systems. However, our preliminary tests using the hydrophobic ceramic cups installed in highly wet soil showed that under conditions of fast drainage of the wetting fluid that is replaced by air, it typically took some time before the cups responded to register the air pressure. Therefore, an attempt was made to develop a more robust method where the time lag is minimized. The tested materials were; 1) ceramic porous cups, 2) sintered stainless steel cups, 3) porous glass discs, and 4) non-woven PTFE fabric. The ceramic cups, sintered stainless steel cups and sintered porous glass discs required hydrophobic treatment, whereas the non-woven PTFE fabric is hydrophobic by itself. To treat the ceramic porous cups, the method proposed by Parker and Lenhard [1988] was adopted. The sintered porous stainless steel cups and porous glass discs were treated by a commercially available water repellant compound. For those four materials, contact angle, water entry pressure, and time lag to respond to an imposed pressure were measured. The best performing material was then tested in a simple heterogeneous column. The column was packed using two sands to form three layers where the coarser sand was sandwitched by two layers of a finer sand. In each layer, soil moisture, water pressure and air pressure were monitored. The soil was initially saturated and suction at the bottom was gradually increased to induce wetting fluid drainage, and followed by a wetting cycle. In the drainage cycle, the coarse middle layer did not drain until air front reached the bottom of the top fine layer. Once the air front reached the fine-coarse interface, air was quickly pulled into the coarse layer. The results showed that the newly developed hydrophobic material showed very small time lag and captured the abrupt air pressure change in the wet soil. In the wetting cycle, we observed positive air pressure which indicated entrapment of air and its compression as wetting proceeded. This behavior cannot be evaluated properly without the rapid measurement of air pressure. The method is currently being applied in a large 2D vertical aquifer with a structured heterogeneity to investigate how air pathways are formed under various flux/temperature conditions at the soil surface.

High-Frequency Electromagnetic Impedance Measurements for Characterization, Monitoring and Verification Efforts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Ki Ha; Becker, Alex; Tseng, Hung-Wen

2004-06-16

Non-invasive, high-resolution imaging of the shallow subsurface is needed for delineation of buried waste, detection of unexploded ordinance, verification and monitoring of containment structures, and other environmental applications. Electromagnetic (EM) measurements at frequencies between 0.1 and 100 MHz are important for such applications, because the induction number of many targets is small and the ability to determine the dielectric permittivity in addition to electrical conductivity of the subsurface is possible. Earlier workers were successful in developing systems for detecting anomalous areas, but no quantifiable information was accurately determined. For high-resolution imaging, accurate measurements are necessary so the field data canmore » be mapped into the space of the subsurface parameters. We are developing a non-invasive method for accurately mapping the electrical conductivity and dielectric permittivity of the shallow subsurface using the EM impedance approach (Frangos, 2001; Lee and Becker, 2001; Song et al., 2002, Tseng et al., 2003). Electric and magnetic sensors are being tested and calibrated on sea water and in a known area against theoretical predictions, thereby insuring that the data collected with the high-frequency impedance (HFI) system will support high-resolution, multi-dimensional imaging techniques.« less

Methane clathrate stability zone variations and gas transport in the Martian subsurface

NASA Astrophysics Data System (ADS)

Karatekin, O.; Gloesener, E.; Dehant, V. M. A.; Temel, O.

2016-12-01

During the last years, several detections of methane in the atmosphere of Mars were reported from Earth-based and Mars orbit instruments with abundances ranging to tens of parts-per-billion by volume (ppbv). Recently, the Curiosity rover detected methane with background levels of 0.7 ppbv and episodic releases of 7 ppbv. Although the methane sources are still unknown, this gas may have been stored in reservoirs of clathrate hydrate in the Martian subsurface where thermodynamics conditions are favourable to their presence. Clathrate hydrates are crystalline compounds constituted by cages formed by hydrogen-bonded water molecules inside of which guest gas molecules are trapped. In this study, methane clathrate stability in the Martian subsurface are investigated and their temporal and spatial variations are studied. Present-day maps of methane clathrate stability zone are produced by coupling the stability conditions of methane clathrate with a subsurface model using the available observations such as the the thermal inertia derived from TES MGS data. Then, a gas transport model has been used to study the methane flux at the surface due to the diffusion of different plausible methane volumes released by clathrate hydrates at variable depths under the Martian surface.

Transport and fate of nitrate and pesticides: Hydrogeology and riparian zone processes

USGS Publications Warehouse

Puckett, L.J.; Hughes, W.B.

2005-01-01

There is continuing concern over potential impacts of widespread application of nutrients and pesticides on ground- and surface-water quality. Transport and fate of nitrate and pesticides were investigated in a shallow aquifer and adjacent stream, Cow Castle Creek, in Orangeburg County, South Carolina. Pesticide and pesticide degradate concentrations were detected in ground water with greatest frequency and largest concentrations directly beneath and downgradient from the corn (Zea mays L.) field where they were applied. In almost all samples in which they were detected, concentrations of pesticide degradates greatly exceeded those of parent compounds, and were still present in ground waters that were recharged during the previous 18 yr. The absence of both parent and degradate compounds in samples collected from deeper in the aquifer suggests that this persistence is limited or that the ground water had recharged before use of the pesticide. Concentrations of NO3- in ground water decreased with increasing depth and age, but denitrification was not a dominant controlling factor. Hydrologic and chemical data indicated that ground water discharges to the creek and chemical exchange takes place within the upper 0.7 m of the streambed. Ground water had its greatest influence on surface-water chemistry during low-flow periods, causing a decrease in concentrations of Cl-, NO3-, pesticides, and pesticide degradates. Conversely, shallow subsurface drainage dominates stream chemistry during high-flow periods, increasing stream concentrations of Cl-, NO3-, pesticides, and pesticide degradates. These results point out the importance of understanding the hydrogeologic setting when investigating transport and fate of contaminants in ground water and surface water. ?? ASA, CSSA, SSSA.

Detection of emerging sunspot regions in the solar interior.

PubMed

Ilonidis, Stathis; Zhao, Junwei; Kosovichev, Alexander

2011-08-19

Sunspots are regions where strong magnetic fields emerge from the solar interior and where major eruptive events occur. These energetic events can cause power outages, interrupt telecommunication and navigation services, and pose hazards to astronauts. We detected subsurface signatures of emerging sunspot regions before they appeared on the solar disc. Strong acoustic travel-time anomalies of an order of 12 to 16 seconds were detected as deep as 65,000 kilometers. These anomalies were associated with magnetic structures that emerged with an average speed of 0.3 to 0.6 kilometer per second and caused high peaks in the photospheric magnetic flux rate 1 to 2 days after the detection of the anomalies. Thus, synoptic imaging of subsurface magnetic activity may allow anticipation of large sunspot regions before they become visible, improving space weather forecast.

Mapping Subsurface Structure at Guar Kepah by using Ground Penetrating Radar

NASA Astrophysics Data System (ADS)

Mansor, Hafizuddin; Rosli, Najmiah; Ismail, N. A.; Saidin, M.; Masnan, S. S. K.

2018-04-01

A Ground Penetrating Radar (GPR) survey was conducted at Guar Kepah to detect buried object before commencement of archaeological gallery construction. The study area covered around 20 m length and 14 m width. 15 GPR lines were constructed from north to south with 20 m length, 1 m spacing and parallel to each other. The 500 MHz closed antenna had been used in this study. The surface findings were noticed before started GPR survey. The data was analysed and interpreted by using Groundvision software and several filters were applied to radargrams to enhance the data. Based on the result, several anomalies were detected. The surface findings also detected by GPR which cause hyperbolic curve in radargrams. The subsurface layer was detected by GPR survey. The anomalies are assigned to several classes based on the pattern of signals obtained in radargrams.

Relating Sub-Surface Ice Features to Physiological Stress in a Climate Sensitive Mammal, the American Pika (Ochotona princeps)

PubMed Central

Wilkening, Jennifer L.; Ray, Chris; Varner, Johanna

2015-01-01

The American pika (Ochotona princeps) is considered a sentinel species for detecting ecological effects of climate change. Pikas are declining within a large portion of their range, and ongoing research suggests loss of sub-surface ice as a mechanism. However, no studies have demonstrated physiological responses of pikas to sub-surface ice features. Here we present the first analysis of physiological stress in pikas living in and adjacent to habitats underlain by ice. Fresh fecal samples were collected non-invasively from two adjacent sites in the Rocky Mountains (one with sub-surface ice and one without) and analyzed for glucocorticoid metabolites (GCM). We also measured sub-surface microclimates in each habitat. Results indicate lower GCM concentration in sites with sub-surface ice, suggesting that pikas are less stressed in favorable microclimates resulting from sub-surface ice features. GCM response was well predicted by habitat characteristics associated with sub-surface ice features, such as lower mean summer temperatures. These results suggest that pikas inhabiting areas without sub-surface ice features are experiencing higher levels of physiological stress and may be more susceptible to changing climates. Although post-deposition environmental effects can confound analyses based on fecal GCM, we found no evidence for such effects in this study. Sub-surface ice features are key to water cycling and storage and will likely represent an increasingly important component of water resources in a warming climate. Fecal samples collected from additional watersheds as part of current pika monitoring programs could be used to further characterize relationships between pika stress and sub-surface ice features. PMID:25803587

[Application research of presacral space drainage tube combined with subcutaneous vacuum pressure suction in the laparoscopic-assisted abdominoperineal resection].

PubMed

Chen, Liqi; Zeng, Changqing; Chi, Liangjie; Huang, Liangxiang; Li, Jiandang

2017-08-25

To study the management for the perineal incision after laparoscopic-assisted abdominoperineal resection for rectal cancer. Clinical data of 87 patients undergoing laparoscopic Miles operation for lower rectal cancer from June 2009 to February 2014 were collected and studied. Presacral space drainage group: presacral space drainage tube was applied in 42 patients. Combined drainage group: presacral space drainage tube combined with subcutaneous vacuum pressure suction was applied in 45 cases. In combined drainage group, except the presacral drainage tube, another drainage tube was placed subcutaneously and connected to a negative pressure ball, which was fixed on the lateral anterior of perineal wound by the further incision and drainage. After subcutaneous tube was placed for 2 weeks, as drainage fluid was limpid and <15 ml/d for 3 days, meanwhile no obvious pelvic fluid was detected by ultrasound, and the wound healed quite well without redness and edema, then the subcutaneous tube with the negative pressure ball could be removed. There were 51 males and 36 females with the mean age of 26-78(56.9±10.8) years old. The laparoscopic Miles operation was successfully completed in all the cases without death and complications. The drainage tube was placed for 4-13(8.0±2.5) days in presacral space drainage group, and for 4-14(6.7±2.4) days in combined drainage group. The subcutaneous tube was placed for 14-24(15.8±3.0) days. The primary healing rate of perineal wound in presacral space drainage group and combined drainage group was 66.7%(28/42) and 91.1%(41/45) respectively, while the perineal wound infection rate was 21.4%(9/42) and 4.4%(2/45) respectively, whose differences between two groups were both significant (χ 2 =7.911, P=0.005 and χ 2 =5.674, P=0.017). Presacral space drainage tube combined with subcutaneous vacuum pressure suction in laparoscopic-assisted abdominoperineal resection for rectal cancer has better efficacy and lower infection rate for perineal incision, which is worth wide application.

Detailed study of water quality, bottom sediment, and biota associated with irrigation drainage in the Salton Sea area, California, 1988-90

USGS Publications Warehouse

Setmire, J.G.; Schroeder, R.A.; Densmore, J.N.; Goodbred, S.O.; Audet, D.J.; Radke, W.R.

1993-01-01

Results of a detailed study by the National Irrigation Water-Quality Program (NIWQP), U.S. Department of the Interior, indicate that factors controlling contaminant concentrations in subsurface irrigation drainwater in the Imperial Valley are soil characteristics, hydrology, and agricultural practices. Higher contaminant concentrations commonly were associated with clayey soils, which retard the movement of irrigation water and thus increase the degree of evaporative concentration. Regression of hydrogen- and oxygen-isotope ratios in samples collected from sumps yields a linear drainwater evaporation line that extrapolates through the isotopic composition of Colorado River water, thus demonstrating that Colorado River water is the sole source of subsurface drainwater in the Imperial Valley. Ratios of selenium to chloride indicate that selenium present in subsurface drainwater throughout the Imperial Valley originates from the Colorado River. The selenium load discharged to the Salton Sea from the Alamo River, the largest contributor, is about 6.5 tons/yr. Biological sampling and analysis showed that drainwater contaminants, including selenium, boron, and DDE, are accumulating in tissues of migratory and resident birds that use food sources in the Imperial Valley and the Salton Sea. Selenium concentration in fish-eating birds, shorebirds, and the endangered Yuma clapper rail were at levels that could affect reproduction. Boron concentrations in migratory waterfowl and resident shorebirds were at levels that potentially could cause reduced growth in young. As a result of DDE contamination of food sources, waterfowl and fish-eating birds in the Imperial Valley may be experiencing reproductive impairment.

A Physically Based Distributed Hydrologic Model with a no-conventional terrain analysis

NASA Astrophysics Data System (ADS)

Rulli, M.; Menduni, G.; Rosso, R.

2003-12-01

A physically based distributed hydrological model is presented. Starting from a contour-based terrain analysis, the model makes a no-conventional discretization of the terrain. From the maximum slope lines, obtained using the principles of minimum distance and orthogonality, the models obtains a stream tubes structure. The implemented model automatically can find the terrain morphological characteristics, e.g. peaks and saddles, and deal with them respecting the stream flow. Using this type of discretization, the model divides the elements in which the water flows in two classes; the cells, that are mixtilinear polygons where the overland flow is modelled as a sheet flow and channels, obtained by the interception of two or more stream tubes and whenever surface runoff occurs, the surface runoff is channelised. The permanent drainage paths can are calculated using one of the most common methods: threshold area, variable threshold area or curvature. The subsurface flow is modelled using the Simplified Bucket Model. The model considers three type of overland flow, depending on how it is produced:infiltration excess;saturation of superficial layer of the soil and exfiltration of sub-surface flow from upstream. The surface flow and the subsurface flow across a element are routed according with the mono-dimensional equation of the kinematic wave. The also model considers the spatial variability of the channels geometry with the flow. The channels have a rectangular section with length of the base decreasing with the distance from the outlet and depending on a power of the flow. The model was tested on the Rio Gallina and Missiaga catchments and the results showed model good performances.

Underground storage of imported water in the San Gorgonio Pass area, southern California

USGS Publications Warehouse

Bloyd, Richard M.

1971-01-01

The San Gorgonio Pass ground-water basin is divided into the Beaumont, Banning, Cabazon, San Timoteo, South Beaumont, Banning Bench, and Singleton storage units. The Beaumont storage unit, centrally located in the agency area, is the largest in volume of the storage units. Estimated long-term average annual precipitation in the San Gorgonio Pass Water Agency drainage area is 332,000 acre-feet, and estimated average annual recoverable water is 24,000 acre-feet, less than 10 percent of the total precipitation. Estimated average annual surface outflow is 1,700 acre-feet, and estimated average annual ground-water recharge is 22,000 acre-feet. Projecting tack to probable steady-state conditions, of the 22.000 acre-feet of recharge, 16,003 acre-feet per year became subsurface outflow into Coachella Valley, 6,000 acre-feet into the Redlands area, and 220 acre-feet into Potrero Canyon. After extensive development, estimated subsurface outflow from the area in 1967 was 6,000 acre-feet into the Redlands area, 220 acre-feet into Potrero Canyon, and 800 acre-feet into the fault systems south of the Banning storage unit, unwatered during construction of a tunnel. Subsurface outflow into Coachella Valley in 1967 is probably less than 50 percent of the steady-state flow. An anticipated 17,000 .acre-feet of water per year will be imported by 1980. Information developed in this study indicates it is technically feasible to store imported water in the eastern part of the Beaumont storage unit without causing waterlogging in the storage area and without losing any significant quantity of stored water.

Development of anomaly detection models for deep subsurface monitoring

NASA Astrophysics Data System (ADS)

Sun, A. Y.

2017-12-01

Deep subsurface repositories are used for waste disposal and carbon sequestration. Monitoring deep subsurface repositories for potential anomalies is challenging, not only because the number of sensor networks and the quality of data are often limited, but also because of the lack of labeled data needed to train and validate machine learning (ML) algorithms. Although physical simulation models may be applied to predict anomalies (or the system's nominal state for that sake), the accuracy of such predictions may be limited by inherent conceptual and parameter uncertainties. The main objective of this study was to demonstrate the potential of data-driven models for leakage detection in carbon sequestration repositories. Monitoring data collected during an artificial CO2 release test at a carbon sequestration repository were used, which include both scalar time series (pressure) and vector time series (distributed temperature sensing). For each type of data, separate online anomaly detection algorithms were developed using the baseline experiment data (no leak) and then tested on the leak experiment data. Performance of a number of different online algorithms was compared. Results show the importance of including contextual information in the dataset to mitigate the impact of reservoir noise and reduce false positive rate. The developed algorithms were integrated into a generic Web-based platform for real-time anomaly detection.

Controls of event-based nutrient transport within nested headwater agricultural watersheds of the western Lake Erie basin

NASA Astrophysics Data System (ADS)

Williams, Mark R.; Livingston, Stanley J.; Penn, Chad J.; Smith, Douglas R.; King, Kevin W.; Huang, Chi-hua

2018-04-01

Understanding the processes controlling nutrient delivery in headwater agricultural watersheds is essential for predicting and mitigating eutrophication and harmful algal blooms in receiving surface waters. The objective of this study was to elucidate nutrient transport pathways and examine key components driving nutrient delivery processes during storm events in four nested agricultural watersheds (298-19,341 ha) in the western Lake Erie basin with poorly drained soils and an extensive artificial drainage network typical of the Midwestern U.S. Concentration-discharge hysteresis patterns of nitrate-nitrogen (NO3-N), dissolved reactive phosphorus (DRP), and particulate phosphorus (PP) occurring during 47 storm events over a 6 year period (2004-2009) were evaluated. An assessment of the factors producing nutrient hysteresis was completed following a factor analysis on a suite of measured environmental variables representing the fluvial and wider watershed conditions prior to, and during the monitored storm events. Results showed the artificial drainage network (i.e., surface tile inlets and subsurface tile drains) in these watersheds was the primary flow pathway for nutrient delivery to streams, but nutrient behavior and export during storm events was regulated by the flow paths to and the intensity of the drainage network, the availability of nutrients, and the relative contributions of upland and in-stream nutrient sources. Potential sources and flow pathways for transport varied among NO3-N, PP, and DRP with results underscoring the challenge of mitigating nutrient loss in these watersheds. Conservation practices addressing both nutrient management and hydrologic connectivity will likely be required to decrease nutrient loss in artificially drained landscapes.

Contrasting nitrogen fate in watersheds using agricultural and water quality information

USGS Publications Warehouse

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.

Spatially explicit shallow landslide susceptibility mapping over large areas

USGS Publications Warehouse

Bellugi, Dino; Dietrich, William E.; Stock, Jonathan D.; McKean, Jim; Kazian, Brian; Hargrove, Paul

2011-01-01

Recent advances in downscaling climate model precipitation predictions now yield spatially explicit patterns of rainfall that could be used to estimate shallow landslide susceptibility over large areas. In California, the United States Geological Survey is exploring community emergency response to the possible effects of a very large simulated storm event and to do so it has generated downscaled precipitation maps for the storm. To predict the corresponding pattern of shallow landslide susceptibility across the state, we have used the model Shalstab (a coupled steady state runoff and infinite slope stability model) which susceptibility spatially explicit estimates of relative potential instability. Such slope stability models that include the effects of subsurface runoff on potentially destabilizing pore pressure evolution require water routing and hence the definition of upslope drainage area to each potential cell. To calculate drainage area efficiently over a large area we developed a parallel framework to scale-up Shalstab and specifically introduce a new efficient parallel drainage area algorithm which produces seamless results. The single seamless shallow landslide susceptibility map for all of California was accomplished in a short run time, and indicates that much larger areas can be efficiently modelled. As landslide maps generally over predict the extent of instability for any given storm. Local empirical data on the fraction of predicted unstable cells that failed for observed rainfall intensity can be used to specify the likely extent of hazard for a given storm. This suggests that campaigns to collect local precipitation data and detailed shallow landslide location maps after major storms could be used to calibrate models and improve their use in hazard assessment for individual storms.

Characterization of particulate and dissolved phosphorus in tile and nearby riverine systems

NASA Astrophysics Data System (ADS)

Jiang, X.; Arai, Y.; David, M.; Gentry, L.

2017-12-01

In the Midwestern U.S., the drainage of agricultural land is predominantly managed by the tile drain system because of its poorly drain properties of clay rich indigenous soils. An accelerated subsurface flow of phosphorus (P) has recently been documented as a primary P transport path in contrast to the typical surface runoff events observed in the Eastern U.S. Recent studies suggested the important role of particulate P (PP) load in agricultural tile drainage water during high flow events. It was hypothesized that PP in the tile water is transported to riverine system contributing to the negative environmental impacts in the Midwestern U.S. In this study, correlation assessment of physicochemical properties of PP in agricultural tile drainage and nearby river samples after a storm event was conducted using a combination of 31P-nuclear magnetic resonance spectroscopy, P K-edge X-ray absorption near edge structure spectroscopy, X-ray diffraction, zetasizer, and transmission electron microscopy. Results show that significantly more colloidal (i.e. 1 nm- 2 µm) and silt-sized (i.e. > 2 µm) particles as well as higher dissolved total P (DTP) and dissolved reactive P (DRP) concentrations existed in river samples than tile samples. Tile and river samples showed similar zeta potential in each particle-size fraction and similar element distributions on colloidal fraction. However, colloidal P concentration and distribution are slightly different between tile and river samples: more colloidal total P and organic P existed in tile colloids than river colloids. The results of P speciation and mineralogical assessment will also be discussed.

Marsh Pool and Tidal Creek Morphodynamics: Dynamic Equilibrium of New England Saltmarshes?

NASA Astrophysics Data System (ADS)

Wilson, C.; FitzGerald, D. M.; Hughes, Z. J.

2012-12-01

Under natural conditions, high saltmarsh platforms in New England exhibit poor drainage, creating waterlogged pannes (where short-form Spartina alterniflora dominates) and stagnant pools that experience tidal exchange only during spring tides and storm-induced flooding events. It is well accepted that a legacy of ditching practices (either for agriculture or mosquito control purposes) provide "overdrainage" of saltmarshes (after Redfield, 1972) and a shift in biogeochemical conditions: lowering of groundwater tables, aeration of soil, and decrease in preserved belowground biomass. Analysis of historical imagery in the Plum Island Estuary of Massachusetts reveals closure and decrease in length of anthropogenic ditches in recent decades is closely linked to marsh pool evolution. Field analyses including stratigraphic transects and elevation surveys suggest these marshes are reverting to natural drainage conditions. Further, an important dynamic interaction exists between saltmarsh pools and natural tidal creeks: creeks incise into pool areas, causing drainage of the pools, and formation of an unvegetated mudflat which can be rapidly recolonized by halophytic Spartina alterniflora vegetation. It was determined that pool and creek dynamics are cyclic in nature. The marsh platform is in dynamic equilibrium with respect to elevation and sea-level whereby marsh elevation may be lost (due to degradation of organic matter and formation of a pool) however may be regained (by creek incision into pools, restoration of tidal exchange, and rapid vertical accretion with Spartina alterniflora recolonization. Since vertical accretion in saltmarshes is a function of both organic and inorganic contributions to the marsh subsurface, it is hypothesized that cannibalization of existing muds is supplying inorganic material in this sediment starved system.

Multiyear nutrient removal performance of three constructed wetlands intercepting tile drain flows from grazed pastures.

PubMed

Tanner, Chris C; Sukias, James P S

2011-01-01

Subsurface tile drain flows can be a major s ource of nurient loss from agricultural landscapes. This study quantifies flows and nitrogen and phosphorus yields from tile drains at three intensively grazed dairy pasture sites over 3- to 5-yr periods and evaluates the capacity of constructed wetlands occupying 0.66 to 1.6% of the drained catchments too reduce nutrient loads. Continuous flow records are combined with automated flow-proportional sampling of nutrient concentrations to calculate tile drain nutrient yields and wetland mass removal rates. Annual drainage water yields rangedfrom 193 to 564 mm (16-51% of rainfall) at two rain-fed sites and from 827 to 853 mm (43-51% of rainfall + irrigation) at an irrigated site. Annually, the tile drains exported 14 to 109 kg ha(-1) of total N (TN), of which 58 to 90% was nitrate-N. Constructed wetlands intercepting these flows removed 30 to 369 gTN m(-2) (7-63%) of influent loadings annually. Seasonal percentage nitrate-N and TN removal were negatively associated with wetland N mass loadings. Wetland P removal was poor in all wetlands, with 12 to 115% more total P exported annually overall than received. Annually, the tile drains exported 0.12 to 1.38 kg ha of total P, of which 15 to 93% was dissolved reactive P. Additional measures are required to reduce these losses or provide supplementary P removal. Wetland N removal performance could be improved by modifying drainage systems to release flows more gradually and improving irrigation practices to reduce drainage losses.

Adaptation Options for Land Drainage Systems Towards Sustainable Agriculture and Environment: A Czech Perspective

NASA Astrophysics Data System (ADS)

Kulhavý, Zbyněk; Fučík, Petr

2015-04-01

In this paper, issues of agricultural drainage systems are introduced and discussed from the views of their former, current and future roles and functioning in the Czech Republic (CR). A methodologically disparate survey was done on thirty-nine model localities in CR with different intensity and state of land drainage systems, aimed at description of commonly occurred problems and possible adaptations of agricultural drainage as perceived by farmers, land owners, landscape managers or by protective water management. The survey was focused on technical state of drainage, fragmentation of land ownership within drained areas as well as on possible conflicts between agricultural and environmental interests in a landscape. Achieved results confirmed that there is obviously an increasing need to reassess some functions of prevailingly single-purpose agricultural drainage systems. Drainage intensity and detected unfavourable technical state of drainage systems as well as the risks connected with the anticipated climate change from the view of possible water scarcity claims for a complex solution. An array of adaptation options for agricultural drainage systems is presented, aiming at enhancement of water retention time and improvement of water quality. It encompasses additional flow-controlling measures on tiles or ditches, or facilities for making selected parts of a drainage system inoperable in order to retain or slow down the drainage runoff, to establish water accumulation zones and to enhance water self-cleaning processes. However, it was revealed that the question of landowner parcels fragmentation on drained land in CR would dramatically complicate design and realization of these measures. Presented solutions and findings are propounded with a respect to contemporary and future state policies and international strategies for sustainable agriculture, water management and environment.

Omitting chest tube drainage after thoracoscopic major lung resection.

PubMed

Ueda, Kazuhiro; Hayashi, Masataro; Tanaka, Toshiki; Hamano, Kimikazu

2013-08-01

Absorbable mesh and fibrin glue applied to prevent alveolar air leakage contribute to reducing the length of chest tube drainage, length of hospitalization and the rate of pulmonary complications. This study investigated the feasibility of omitting chest tube drainage in selected patients undergoing thoracoscopic major lung resection. Intraoperative air leakages were sealed with fibrin glue and absorbable mesh in patients undergoing thoracoscopic major lung resection. The chest tube was removed just after tracheal extubation if no air leakages were detected in a suction-induced air leakage test, which is an original technique to confirm pneumostasis. Patients with bleeding tendency or extensive thoracic adhesions were excluded. Chest tube drainage was omitted in 29 (58%) of 50 eligible patients and was used in 21 (42%) on the basis of suction-induced air leakage test results. Male gender and compromised pulmonary function were significantly associated with the failure to omit chest tube drainage (both, P < 0.05). Regardless of omitting the chest tube drainage, there were no adverse events during hospitalization, such as subcutaneous emphysema, pneumothorax, pleural effusion or haemothorax, requiring subsequent drainage. Furthermore, there was no prolonged air leakage in any patients: The mean length of chest tube drainage was only 0.9 days. Omitting the chest tube drainage was associated with reduced pain on the day of the operation (P = 0.046). The refined strategy for pneumostasis allowed the omission of chest tube drainage in the majority of patients undergoing thoracoscopic major lung resection without increasing the risk of adverse events, which may contribute to a fast-track surgery.

Effects of hydraulic and geologic factors on streamflow of the Yakima River Basin, Washington

USGS Publications Warehouse

Kinnison, Hallard B.; Sceva, Jack E.

1963-01-01

The Yakima River basin, in south-central Washington, is the largest single river system entirely within the confines of the State. Its waters are the most extensively utilized of all the rivers in Washington. The river heads high on the eastern slope of the Cascade Mountains, flows for 180 miles in a generally southeast direction, and discharges into the Columbia River. The western part of the basin is a mountainous area formed by sedimentary, volcanic, and metamorphic rocks, which generally have a low capacity for storing and transmitting water. The eastern part of the basin is. formed by a thick sequence of lava flows that have folded into long ridges and troughs. Downwarped structural basins between many of the ridges are partly filled with younger sedimentary deposits, which at some places are many hundreds of feet thick. The Yakima River flows from structural basin to structural basin through narrow water gaps that have been eroded through the anticlinal ridges. Each basin is also a topographic basin and a ground-water subbasin. A gaging station will measure the total outflow of a drainage area only if it is located at the surface outlet of a ground-water subbasin and then only if the stream basin is nearly coextensive with the ground-water subbasin. Many gaging stations in the Yakima basin are so located. The geology, hydrology, size. and location of 25 ground-water subbasins are described. Since the settlement of the valley began, the development of the land and water resources have caused progressive changes in the natural regimen of the basin's runoff. These changes have resulted from diversion of water from the streams, the application of water on the land for irrigation, the storage and release of flood waters, the pumping of ground water, and other factors Irrigation in the Yakima basin is reported 'to have begun about 1864. In 1955 about 425,000 acres were under irrigation. During the past 60-odd years many gaging stations have been operated at different sites within the basin. Only stations in the upper reaches, such as those below Keechelus, Kachess, or Cle Elum Lakes, give discharge records which are an accurate measure of the natural outflow of the drainage area. Farther down, stream, as the utilization of water becomes more extensive, the records at a gaging station show the discharge passing a particular point, but they do not reflect the natural outflow of the basin. Large canals divert water for use on lands above a station or carry it around a station for irrigation downstream. The deep sedimentary deposits within subbasins and the overlying alluvial gravels permit downvalley movement of large subsurface flows which bypass the gaging stations, except in the near vicinity of the water gaps. At the water gaps ground water rises to the surface, becoming streamflow, and can be accurately measured. The location of gaging stations within each subbasin is important, therefore, in determining whether the flow measured represents the total downvalley outflow or whether it is merely the surface-water component. Surface and subsurface factors that may affect the discharge records at each gaging station in the Yakima River basin include a description of upstream diversions, surface return flows, bypass canals, storage reservoirs, subsurface bypass flows, ground-water withdrawals, and other items. The available data are not sufficiently complete to permit a quantitative determination of the total basin yield at most gaging stations. However, data on the existing bypass channels, such as canals and drainage ditches, and on related subsurface movement of water provide valuable information necessary to proper use and interpretation of the streamflow records.

From Ground Truth to Space: Surface, Subsurface and Remote Observations Associated with Nuclear Test Detection

NASA Astrophysics Data System (ADS)

Sussman, A. J.; Anderson, D.; Burt, C.; Craven, J.; Kimblin, C.; McKenna, I.; Schultz-Fellenz, E. S.; Miller, E.; Yocky, D. A.; Haas, D.

2016-12-01

Underground nuclear explosions (UNEs) result in numerous signatures that manifest on a wide range of temporal and spatial scales. Currently, prompt signals, such as the detection of seismic waves provide only generalized locations and the timing and amplitude of non-prompt signals are difficult to predict. As such, research into improving the detection, location, and identification of suspect events has been conducted, resulting in advancement of nuclear test detection science. In this presentation, we demonstrate the scalar variably of surface and subsurface observables, briefly discuss current capabilities to locate, detect and characterize potential nuclear explosion locations, and explain how emergent technologies and amalgamation of disparate data sets will facilitate improved monitoring and verification. At the smaller scales, material and fracture characterization efforts on rock collected from legacy UNE sites and from underground experiments using chemical explosions can be incorporated into predictive modeling efforts. Spatial analyses of digital elevation models and orthoimagery of both modern conventional and legacy nuclear sites show subtle surface topographic changes and damage at nearby outcrops. Additionally, at sites where such technology cannot penetrate vegetative cover, it is possible to use the vegetation itself as both a companion signature reflecting geologic conditions and showing subsurface impacts to water, nutrients, and chemicals. Aerial systems based on RGB imagery, light detection and ranging, and hyperspectral imaging can allow for combined remote sensing modalities to perform pattern recognition and classification tasks. Finally, more remote systems such as satellite based synthetic aperture radar and satellite imagery are other techniques in development for UNE site detection, location and characterization.

Fibre optic confocal imaging (FOCI) for subsurface microscopy of the colon in vivo.

PubMed Central

Delaney, P M; King, R G; Lambert, J R; Harris, M R

1994-01-01

Fibre optic confocal imaging (FOCI) is a new type of microscopy which has been recently developed (Delaney et al. 1993). In contrast to conventional light microscopy, FOCI and other confocal techniques allow clear imaging of subsurface structures within translucent objects. However, unlike conventional confocal microscopes which are bulky (because of a need for accurate alignment of large components) FOCI allows the imaging end to be miniaturised and relatively mobile. FOCI is thus particularly suited for clear subsurface imaging of structures within living animals or subjects. The aim of the present study was to assess the suitability of using FOCI for imaging of subsurface structures within the colon, both in vitro (human and rat biopsies) and in vivo (in rats). Images were obtained in fluorescence mode (excitation 488 nm, detection above 515 nm) following topical application of fluorescein. By this technique the glandular structure of the colon was imaged. FOCI is thus suitable for subsurface imaging of the colon in vivo. Images Fig. 2 Fig. 3 PMID:8157487

Linking sediment structure, hydrological functioning and biogeochemical cycling in disturbed coastal saltmarshes and implications for vegetation development

NASA Astrophysics Data System (ADS)

Spencer, Kate; Harvey, Gemma; James, Tempest; Simon, Carr; Michelle, Morris

2014-05-01

Saltmarsh restoration undoubtedly provides environmental enhancement, with vegetation quickly re-establishing following the breach of sea walls and subsequent tidal inundation of previously defended areas. Yet evidence increasingly suggests that the restored saltmarshes do not have the same biological characteristics as their natural counterparts (Mossman et al. 2012) and this may be in part be due to physicochemical parameters at the site including anoxia and poor drainage. Hence, restored saltmarshes may not offer the range and quality of ecosystem services anticipated. These environments will have been 'disturbed' by previous land use and there is little understanding of the impacts of this disturbance on the wider hydrogeomorphic and biogeochemical functioning in restored saltmarshes and the implications for saltmarsh vegetation development. This study examines linkages between physical sediment characteristics, sediment structure (using X-ray microtomography), sub-surface hydrology (using pressure transducers and time series analysis), and sediment and porewater geochemistry (major and trace elements, major anions) in sediment cores collected from undisturbed saltmarshes and those restored by de-embankment. Sub-surface sediments in restored saltmarshes have lower organic matter content, lower moisture content and higher bulk density than undisturbed sites. Using X-ray tomography a clear horizon can be observed which separates relict agricultural soils at depth with less dense and structureless sediments deposited since de-embankment. Ratios of open to closed pore space suggest that while undisturbed saltmarshes have the highest porosity, restored saltmarshes have larger void spaces, but limited pore connectivity. Sub-surface hydrological response to tidal flooding was subdued in the restored compared to the undisturbed site, suggesting that porewater flow may be impeded. Time series analysis indicated that flow pathways differ in restored saltmarsh sediments with preferential horizontal flows. The undisturbed saltmarsh displayed typical vertical geochemical sediment profiles. However, in the restored sites total Fe and Mn are elevated at depth indicating an absence of diagenetic cycling, whilst porewater sulphate and nitrate increased at depth suggesting that vertical solute transport is impeded in restored sites. In surface sediments, though total Hg concentrations are similar, Hg methylation rates are significantly higher than in the undisturbed saltmarsh suggesting that surface anoxia and poor drainage may result in increased mobilization and bioavailability of Hg. These findings have implications for the wider biogeochemical ecosystem services offered by saltmarsh restoration and the water-logged, anoxic conditions produced are unsuitable for seedling germination and plant growth. This highlights the need for integrated understanding of physical and biogeochemical processes.

Integration of airborne optical and thermal imagery for archaeological subsurface structures detection: the Arpi case study (Italy)

NASA Astrophysics Data System (ADS)

Bassani, C.; Cavalli, R. M.; Fasulli, L.; Palombo, A.; Pascucci, S.; Santini, F.; Pignatti, S.

2009-04-01

The application of Remote Sensing data for detecting subsurface structures is becoming a remarkable tool for the archaeological observations to be combined with the near surface geophysics [1, 2]. As matter of fact, different satellite and airborne sensors have been used for archaeological applications, such as the identification of spectral anomalies (i.e. marks) related to the buried remnants within archaeological sites, and the management and protection of archaeological sites [3, 5]. The dominant factors that affect the spectral detectability of marks related to manmade archaeological structures are: (1) the spectral contrast between the target and background materials, (2) the proportion of the target on the surface (relative to the background), (3) the imaging system characteristics being used (i.e. bands, instrument noise and pixel size), and (4) the conditions under which the surface is being imaged (i.e. illumination and atmospheric conditions) [4]. In this context, just few airborne hyperspectral sensors were applied for cultural heritage studies, among them the AVIRIS (Airborne Visible/Infrared Imaging Spectrometer), the CASI (Compact Airborne Spectrographic Imager), the HyMAP (Hyperspectral MAPping) and the MIVIS (Multispectral Infrared and Visible Imaging Spectrometer). Therefore, the application of high spatial/spectral resolution imagery arise the question on which is the trade off between high spectral and spatial resolution imagery for archaeological applications and which spectral region is optimal for the detection of subsurface structures. This paper points out the most suitable spectral information useful to evaluate the image capability in terms of spectral anomaly detection of subsurface archaeological structures in different land cover contexts. In this study, we assess the capability of MIVIS and CASI reflectances and of ATM and MIVIS emissivities (Table 1) for subsurface archaeological prospection in different sites of the Arpi archaeological area (southern Italy). We identify, for the selected sites, three main land cover overlying the buried structures: (a) photosynthetic (i.e. green low vegetation), (b) non-photosynthetic vegetation (i.e. yellow, dry low vegetation), and (c) dry bare soil. Afterwards, we analyse the spectral regions showing an inherent potential for the archaeological detection as a function of the land cover characteristics. The classified land cover units have been used in a spectral mixture analysis to assess the land cover fractional abundance surfacing the buried structures (i.e. mark-background system). The classification and unmixing results for the CASI, MIVIS and ATM remote sensing data processing showed a good accordance both in the land cover units and in the subsurface structures identification. The integrated analysis of the unmixing results for the three sensors allowed us to establish that for the land cover characterized by green and dry vegetation (occurrence higher than 75%), the visible and near infrared (VNIR) spectral regions better enhance the buried man-made structures. In particular, if the structures are covered by more than 75% of vegetation the two most promising wavelengths for their detection are the chlorophyll peak at 0.56 m (Visible region) and the red edge region (0.67 to 0.72 m; NIR region). This result confirms that the variation induced by the subsurface structures (e.g., stone walls, tile concentrations, pavements near the surface, road networks) to the natural vegetation growth and/or colour (i.e., for different stress factors) is primarily detectable by the chlorophyll peak and the red edge region applied for the vegetation stress detection. Whereas, if dry soils cover the structures (occurrence higher than 75%), both the VNIR and thermal infrared (TIR) regions are suitable to detect the subsurface structures. This work demonstrates that airborne reflectances and emissivities data, even though at different spatial/spectral resolutions and acquisition time represent an effective and rapid tool to detect subsurface structures within different land cover contexts. As concluding results, this study reveals that the airborne multi/hyperspectral image processing can be an effective and cost-efficient tool to perform a preliminary analysis of those areas where large cultural heritage assets prioritising and localizing the sites where to apply near surface geophysics surveys. Spectral Region Spectral Resolution ( m )Spectral Range ( m) Spatial Resolution (m)IFOV (deg) ATM VIS-NIR SWIR-TIR (tot 12 ch) variable from 24 to 3100 0.42 - 1150 2 0.143 CASI VNIR (48 ch.) 0.01 0.40-0.94 2 0.115 MIVIS VNIR (28ch.) 0.02 (VIS) 0.05 (NIR) 0.43-0.83 (VIS) 1.15-1.55 (NIR) 6 - 7 0.115 SWIR (64ch.) 0.09 1.983-2.478 TIR (10ch.) 0.34-0.54 8.180-12.700 Table 1. Characteristics of airborne sensors used for the Arpi test area. 1 References 2 [1] Beck, A., Philip, G., Abdulkarim, M. and Donoghue, D., 2007. Evaluation of Corona and Ikonos high resolution satellite imagery for archaeological prospection in western Syria. Antiquity, 81: 161-175. 3 [2] Altaweel, M., 2005. The Use of ASTER Satellite Imagery in Archaeological Contexts. Archaeological Prospection, 12: 151- 166. 4 [3] Cavalli, R.M.; Colosi, F.; Palombo, A.; Pignatti, S.; Poscolieri, M. Remote hyperspectral imagery as a support to archaeological prospection. J. of Cultural Heritage 2007, 8, 272-283. 5 [4] Kucukkaya, A.G. Photogrammetry and remote sensing in archaeology. J. Quant. Spectrosc. Radiat. Transfer 2004, 97(1-3), 83-97. [5] Rowlands, A.; Sarris, A. Detection of exposed and subsurface archaeological remains using multi-sensor remote sensing. J. of Archaeological Science 2007, 34, 795-803.

Simulation of rainfall-runoff response in mined and unmined watersheds in coal areas of West Virginia

USGS Publications Warehouse

Puente, Celso; Atkins, John T.

1989-01-01

Meteorologic and hydrologic data from five small watersheds in the coal areas of West Virginia were used to calibrate and test the U.S. Geological Survey Precipitation-Runoff Modeling System for simulating streamflow under various climatic and land-use conditions. Three of the basins--Horsecamp Run, Gilmer Run, and Collison Creek--are primarily forested and relatively undisturbed. The remaining basins--Drawdy Creek and Brier Creek-are extensively mined, both surface and underground above stream drainage level. Low-flow measurements at numerous synoptic sites in the mined basins indicate that coal mining has substantially altered the hydrologic system of each basin. The effects of mining on streamflow that were identified are (1) reduced base flow in stream segments underlain by underground mines, (2) increased base flow in streams that are downdip and stratigraphically below the elevation of the mined coal beds, and (3) interbasin transfer of ground water through underground mines. These changes probably reflect increased permeability of surface rocks caused by subsidence fractures associated with collapsed underground mines in the basin. Such fractures would increase downward percolation of precipitation, surface and subsurface flow, and ground-water flow to deeper rocks or to underground mine workings. Model simulations of the water budgets for the unmined basins during the 1972-73 water years indicate that total annual runoff averaged 60 percent of average annual precipitation; annual evapotranspiration losses averaged 40 percent of average annual precipitation. Of the total annual runoff, approximately 91 percent was surface and subsurface runoff and 9 percent was groundwater discharge. Changes in storage in the soil zone and in the subsurface and ground-water reservoirs in the basins were negligible. In contrast, water-budget simulations for the mined basins indicate significant differences in annual recharge and in total annual runoff. Model simulations of the water budget for Drawdy Creek basin indicate that total annual runoff during 1972-73 averaged only 43 percent of average annual precipitation--the lowest of all study basins; annual evapotranspiration losses averaged 49 percent, and interbasin transfer of ground-water losses averaged about 8 percent. Of the total annual runoff, approximately 74 percent was surface and subsurface flow and 26 percent was ground-water discharge. The low total annual runoff at Drawdy Creek probably reflects increased recharge of precipitation and surface and subsurface flow losses to ground water. Most of the increase in ground-water storage is, in turn, lost to a ground-water sink--namely, interbasin transfer of ground water by gravity drainage and (or) mine pumpage from underground mines that extend to adjacent basins. Hypothetical mining situations were posed for model analysis to determine the effects of increased mining on streamflow in the mined basins. Results of model simulations indicate that streamflow characteristics, the water budget, and the seasonal distribution of streamflow would be significantly modified in response to an increase in mining in the basins. Simulations indicate that (1) total annual runoff in the basins would decrease because of increased surface- and subsurface-flow losses and increased recharge of precipitation to ground water (these losses would tend to reduce medium to high flows mainly during winter and spring when losses would be greatest), (2) extreme high flows in response to intense rainstorms would be negligibly affected, regardless of the magnitude of mining in the basins, (3) ground-water discharge also would decrease during winter and spring, but the amount and duration of low flows during summer and fall would substantially increase in response to increased ground-water storage in rocks and in underground mines, and (4) the increase in ground-water storage in the basins would be depleted, mostly by increased losses to a grou

Imaging of Subsurface Corrosion Using Gradient-Field Pulsed Eddy Current Probes with Uniform Field Excitation

PubMed Central

Ren, Shuting; Yan, Bei; Zainal Abidin, Ilham Mukriz; Wang, Yi

2017-01-01

A corrosive environment leaves in-service conductive structures prone to subsurface corrosion which poses a severe threat to the structural integrity. It is indispensable to detect and quantitatively evaluate subsurface corrosion via non-destructive evaluation techniques. Although the gradient-field pulsed eddy current technique (GPEC) has been found to be superior in the evaluation of corrosion in conductors, it suffers from a technical drawback resulting from the non-uniform field excited by the conventional pancake coil. In light of this, a new GPEC probe with uniform field excitation for the imaging of subsurface corrosion is proposed in this paper. The excited uniform field makes the GPEC signal correspond only to the field perturbation due to the presence of subsurface corrosion, which benefits the corrosion profiling and sizing. A 3D analytical model of GPEC is established to analyze the characteristics of the uniform field induced within a conductor. Following this, experiments regarding the imaging of subsurface corrosion via GPEC have been carried out. It has been found from the results that the proposed GPEC probe with uniform field excitation not only applies to the imaging of subsurface corrosion in conductive structures, but provides high-sensitivity imaging results regarding the corrosion profile and opening size. PMID:28758985

Imaging of Subsurface Corrosion Using Gradient-Field Pulsed Eddy Current Probes with Uniform Field Excitation.

PubMed

Li, Yong; Ren, Shuting; Yan, Bei; Zainal Abidin, Ilham Mukriz; Wang, Yi

2017-07-31

A corrosive environment leaves in-service conductive structures prone to subsurface corrosion which poses a severe threat to the structural integrity. It is indispensable to detect and quantitatively evaluate subsurface corrosion via non-destructive evaluation techniques. Although the gradient-field pulsed eddy current technique (GPEC) has been found to be superior in the evaluation of corrosion in conductors, it suffers from a technical drawback resulting from the non-uniform field excited by the conventional pancake coil. In light of this, a new GPEC probe with uniform field excitation for the imaging of subsurface corrosion is proposed in this paper. The excited uniform field makes the GPEC signal correspond only to the field perturbation due to the presence of subsurface corrosion, which benefits the corrosion profiling and sizing. A 3D analytical model of GPEC is established to analyze the characteristics of the uniform field induced within a conductor. Following this, experiments regarding the imaging of subsurface corrosion via GPEC have been carried out. It has been found from the results that the proposed GPEC probe with uniform field excitation not only applies to the imaging of subsurface corrosion in conductive structures, but provides high-sensitivity imaging results regarding the corrosion profile and opening size.

Plug identification in drainage system using electromagnetic wave

NASA Astrophysics Data System (ADS)

Hijriani, Arifa; Utama, Aji Surya; Boas, Andrianus; Mukti, M. Ridho; Widodo

2017-07-01

The evaluation of drainage system's performance is an important thing to do to prevent flooding. Conventionally the Government evaluates the drainage system by opening one by one the lid of drainage and detects the plug manually. This method is not effective and efficient because this method need many people, much time and relatively expensive. The purpose of this paper is to identify plugs in drainage system in G St. at Bandung Institute of Technology by using electromagnetic wave. Ground Penetrating Radar (GPR) is one of geophysics method that using electromagnetic wave with high frequency. GPR is a non-destructive method with high resolution imaging for shallow depth (˜100m) and relatively cheap. We could identify the plug without opening the lid manually so that we could save much time. GPR's sensitivity is depends on resistivity, magnetic permeability, and permittivity of an object. The result of this research is we could identify the plug on the radargram that observed by a build-up amplitude anomaly.

A spatially offset Raman spectroscopy method for non-destructive detection of gelatin-encapsulated powders

USDA-ARS?s Scientific Manuscript database

Non-destructive subsurface detection of encapsulated, coated, or seal-packaged foods and pharmaceuticals can help prevent distribution and consumption of counterfeit or hazardous products. This study used a Spatially Offset Raman Spectroscopy (SORS) method to detect and identify urea, ibuprofen, and...

Autonomous microexplosives subsurface tracing system final report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Engler, Bruce Phillip; Nogan, John; Melof, Brian Matthew

The objective of the autonomous micro-explosive subsurface tracing system is to image the location and geometry of hydraulically induced fractures in subsurface petroleum reservoirs. This system is based on the insertion of a swarm of autonomous micro-explosive packages during the fracturing process, with subsequent triggering of the energetic material to create an array of micro-seismic sources that can be detected and analyzed using existing seismic receiver arrays and analysis software. The project included investigations of energetic mixtures, triggering systems, package size and shape, and seismic output. Given the current absence of any technology capable of such high resolution mapping ofmore » subsurface structures, this technology has the potential for major impact on petroleum industry, which spends approximately $1 billion dollar per year on hydraulic fracturing operations in the United States alone.« less

Development of hand-held thermographic inspection technologies.

DOT National Transportation Integrated Search

2009-09-01

This study explored the application of hand-held thermographic cameras for the detection of subsurface delaminations in concrete : bridges. The goal of the research was to provide maintenance and inspection personnel with an effective tool for detect...

PleurAlert: an augmented chest drainage system with electronic sensing, automated alerts and internet connectivity.

PubMed

Leeson, Cory E; Weaver, Robert A; Bissell, Taylor; Hoyer, Rachel; McClain, Corinne; Nelson, Douglas A; Samosky, Joseph T

2012-01-01

We have enhanced a common medical device, the chest tube drainage container, with electronic sensing of fluid volume, automated detection of critical alarm conditions and the ability to automatically send alert text messages to a nurse's cell phone. The PleurAlert system provides a simple touch-screen interface and can graphically display chest tube output over time. Our design augments a device whose basic function dates back 50 years by adding technology to automate and optimize a monitoring process that can be time consuming and inconvenient for nurses. The system may also enhance detection of emergency conditions and speed response time.

Temporal geochemical variations in above- and below-drainage coal mine discharge

USGS Publications Warehouse

Burrows, Jill E.; Peters, Stephen C.; Cravotta, Charles A.

2015-01-01

Water quality data collected in 2012 for 10 above- and 14 below-drainage coal mine discharges (CMDs), classified by mining or excavation method, in the anthracite region of Pennsylvania, USA, are compared with data for 1975, 1991, and 1999 to evaluate long-term (37 year) changes in pH, SO42−, and Fe concentrations related to geochemistry, hydrology, and natural attenuation processes. We hypothesized that CMD quality will improve over time because of diminishing quantities of unweathered pyrite, decreased access of O2 to the subsurface after mine closure, decreased rates of acid production, and relatively constant influx of alkalinity from groundwater. Discharges from shafts, slopes, and boreholes, which are vertical or steeply sloping excavations, are classified as below-drainage; these receive groundwater inputs with low dissolved O2, resulting in limited pyrite oxidation, dilution, and gradual improvement of CMD water quality. In contrast, discharges from drifts and tunnels, which are nearly horizontal excavations into hillsides, are classified as above-drainage; these would exhibit less improvement in water quality over time because the rock surfaces continue to be exposed to air, which facilitates sustained pyrite oxidation, acid production, and alkalinity consumption. Nonparametric Wilcoxon matched-pair signed rank tests between 1975 and 2012 samples indicate decreases in Fe and SO42− concentrations were highly significant (p < 0.05) and increases in pH were marginally significant (p < 0.1) for below-drainage discharges. For above-drainage discharges, changes in Fe and SO42−concentrations were not significant, and increases in pH were highly significant between 1975 and 2012. Although a greater proportion of above-drainage discharges were net acidic in 2012 compared to below-drainage discharges, the increase in pH between 1975 and 2012 was greater for above- (median pH increase from 4.4 to 6.0) compared to below- (median pH increase from 5.6 to 6.1) drainage discharges. For cases where O2 is limited, transformation of aqueous FeII species to FeIII may be kinetically limited. In contrast, where O2 is abundant, aqueous Fe concentrations may be limited by FeIIImineral precipitation; thus, trends in Fe may not follow those for SO42−. In either case, when the supply of alkalinity is sufficient to buffer decreased acidity, the pH could increase by a step trend from strongly acidic (3–3.5) to near neutral (6–6.5) values. Modeled equilibrium with respect to FeIII precipitates varies with pH and Fe and SO42−reconcentrations: increasing pH promotes the formation of ferrihydrite, while decreasing concentrations of Fe limit the formation of ferrihydrite, and decreasing Fe and SO42−concentrations limit the precipitation of schwertmannite and favor formation of FeIIIhydroxyl complexes and uncomplexed Fe2+ and Fe3+. The analysis of the long-term geochemical changes in CMDs in the anthracite field and the effect of the hydrologic setting on water quality presented in this paper can help prioritize CMD remediation and facilitate selection and design of the most appropriate treatment systems.

Nasal septal abscess caused by anaerobic bacteria of oral flora.

PubMed

Hyo, Yukiyoshi; Fukushima, Hisaki; Harada, Tamotsu; Hara, Hirotaka

2018-06-07

Although nasal septal abscess (NSA) was formerly common, it has become rare since the development of antibiotics. NSA, if left untreated, can lead to intracranial complications such as meningitis and eventually result in saddle-nose deformity. NSA often occurs after injury, and indigenous skin bacteria such as Staphylococcus aureus are frequently detected. We treated a patient who had injured the upper alveolus in a fall on the stairs and developed NSA two weeks later. Anaerobic bacteria, including Veillonella parvula and Peptostreptococcus sp., were detected. Symptoms were relieved by needle and incisional drainage. Our patient represents a very rare case of NSA in terms of the cause of onset and the detected bacteria. Early drainage can result in good outcomes. Copyright © 2018 Elsevier B.V. All rights reserved.

Seismic Characterization of the Blue Mountain Geothermal Site

NASA Astrophysics Data System (ADS)

Templeton, D. C.; Matzel, E.; Cladouhos, T. T.

2017-12-01

All fluid injection activities have the potential to induce earthquakes by modifying the state of stress in the subsurface. In geothermal areas, small microearthquakes can be a beneficial outcome of these stress perturbations by providing direct subsurface information that can be used to better understand and manage the underground reservoir. These events can delineate the active portions of the subsurface that have slipped in response to pore fluid pressure changes or temperature changes during and after fluid injection. Here we investigate the seismic activity within the Blue Mountain Geothermal Power Plant located in Humboldt County, Nevada between December 2015 to May 2016. We compare the effectiveness of direct spatial-temporal cross-correlation templates with Matched Field Processing (MFP) derived templates and compare these results with earthquake detection results from a traditional STA/LTA algorithm. Preliminary results show significant clustering of microearthquakes, most probably influenced by plant operations. The significant increase in data availability that advanced earthquake detection methods can provide improves the statistical analyses of induced seismicity sequences, reveal critical information about the ongoing evolution of the subsurface reservoir, and better informs the construction of models for hazard assessments. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

Assessment of Filter Materials for Removal of Contaminants From Agricultural Drainage Waters

NASA Astrophysics Data System (ADS)

Allred, B. J.

2007-12-01

Fertilizer nutrients and pesticides applied on farm fields, especially in the Midwest U.S., are commonly intercepted by buried agricultural drainage pipes and then discharged into local streams and lakes, oftentimes resulting in an adverse environmental impact on these surface water bodies. Low cost filter materials have the potential to remove nutrient and pesticide contaminants from agricultural drainage waters before these waters are released from the farm site. Batch tests were conducted to find filter materials potentially capable of removing nutrient (nitrate and phosphate) and pesticide (atrazine) contaminants from subsurface drainage waters. For each batch test, stock solution (40 g) and filter material (5 g) were combined in 50 mL Teflon centrifuge tubes and mixed with a rotator for 24 hours. The stock solution contained 50 mg/L nitrate-N, 0.25 mg/L phosphate-P, 0.4 mg/L atrazine, 570 mg/L calcium sulfate, and 140 mg/L potassium chloride. Calcium sulfate and potassium chloride were added so that the stock solution would contain anions and cations normally found in agricultural drainage waters. There were six replicate batch tests for each filter material. At the completion of each test, solution was removed from the centrifuge tube and analyzed for nitrate-N, phosphate-P, and atrazine. A total of 38 filter materials were tested, which were divided into five classes; high carbon content substances, high iron content substances, high aluminum content substances, surfactant modified clay/zeolite, and coal combustion products. Batch test results generally indicate, that with regard to the five classes of filter materials; high carbon content substances adsorbed atrazine very effectively; high iron content substances worked especially well removing almost all of the phosphate present; high aluminum content substances lowered phosphate levels; surfactant modified clay/zeolite substantially reduced both nitrate and atrazine; and coal combustion products significantly decreased phosphate amounts. For the 38 specific filter materials evaluated, based on a 60 percent contaminant reduction level, 12 materials removed nitrate, 26 materials removed phosphate, and 21 materials removed atrazine. Furthermore, 2 materials removed zero contaminants, 16 materials removed one contaminant, 17 materials removed two contaminants, and 3 of the materials removed all three contaminants. The most effective filter materials proved to be a steam activated carbon, a zero valent iron and sulfer modified iron mixture, and a surfactant modified clay. The findings of this study indicate that there are a variety of filter materials, either separately or in combination, which have the potential to treat agricultural drainage waters.

Forecasting selenium discharges to the San Francisco Bay-Delta Estuary: ecological effects of a proposed San Luis drain extension

USGS Publications Warehouse

Luoma, Samuel N.; Presser, Theresa S.

2000-01-01

During the next few years, federal and state agencies may be required to evaluate proposals and discharge permits that could significantly change selenium (Se) inputs to the San Francisco Bay-Delta Estuary (Bay-Delta), particularly in the North Bay (i.e., Suisun Bay and San Pablo Bay). These decisions may include discharge requirements for an extension of the San Luis Drain (SLD) to the estuary to convey subsurface agricultural drainage from the western San Joaquin Valley (SJV), a renewal of an agreement to allow the existing portion of the SLD to convey subsurface agricultural drainage to a tributary of the San Joaquin River (SJR) (coincident with changes in flow patterns of the lower SJR), and refinements to promulgated Se criteria for the protection of aquatic life for the estuary. Understanding the biotransfer of Se is essential to evaluating the fate and impact of proposed changes in Se discharges to the Bay-Delta. However, past monitoring programs have not addressed the specific protocols necessary for an element that bioaccumulates. Confusion about Se threats in the past have stemmed from failure to consider the full complexity of the processes that result in Se toxicity. Past studies show that predators are more at risk from Se contamination than their prey, making it difficult to use traditional methods to predict risk from environmental concentrations alone. In this report, we employ a novel procedure to model the fate of Se under different, potentially realistic load scenarios from the SJV. For each potential load, we progressively forecast the resulting environmental concentrations, speciation, transformation to particulate form, bioaccumulation by invertebrates, trophic transfer to predators, and effects in those predators. Enough is known to establish a first order understanding of effects should Se be discharged directly into the North Bay via a conveyance such as the SLD. Our approach uses 1) existing knowledge concerning the biogeochemical reactions of Se (e.g., speciation, partitioning between dissolved and particulate forms, and bivalve assimilation efficiency) and 2) site-specific data mainly from 1986 to 1996 on clams and bottom-feeding fish and birds. Forecasts of Se loading from oil refineries and agricultural drainage from the SJV enable the calculation of a composite freshwater endmember Se concentration at the head of the estuary and at Carquinez Strait as a foundation for modeling. Our analysis of effects also takes into account the mode of conveyance for agricultural drainage (i.e., the SLD or SJR). The effects of variable flows on a seasonal or monthly basis from the Sacramento River and SJR are also considered. The results of our forecasts for external SJV watershed sources of Se mirror predictions made since 1955 of a worsening salt (and by inference, Se) buildup exacerbated by the arid climate and irrigation for agricultural use. We show that the reservoir of Se in the SJV is sufficient to provide loading at an annual rate of approximately 42,500 pounds (lbs) of Se to a Bay-Delta disposal point for 63 to 304 years at the lower range of our projections, even if influx of Se from the California Coast Ranges could be curtailed. Disposal of wastewaters on an annual basis outside of the SJV may slow the degradation of valley resources, but drainage alone cannot alleviate the salt and Se buildup in the SJV, at least within a century. Our forecasts show the different proportions of Se loading to the Bay-Delta. Oil refinery loads from 1986 to 1992 ranged from 11 to 15 lbs Se per day; with treatment and cleanup, loads decreased to 3 lbs Se per day in 1999. In contrast, SJV agricultural drainage loads could range from of 45 to 117 lbs Se per day across a set of reasonable conditions. Components of this valley-wide load include five source subareas (i.e., Grassland, Westlands, Tulare, Kern, and Northern) based on water and drainage management. Loads vary per subarea mainly because of proximity of the s

A size selective porous silicon grating-coupled Bloch surface and sub-surface wave biosensor.

PubMed

Rodriguez, Gilberto A; Ryckman, Judson D; Jiao, Yang; Weiss, Sharon M

2014-03-15

A porous silicon (PSi) grating-coupled Bloch surface and sub-surface wave (BSW/BSSW) biosensor is demonstrated to size selectively detect the presence of both large and small molecules. The BSW is used to sense large immobilized analytes at the surface of the structure while the BSSW that is confined inside but near the top of the structure is used to sensitively detect small molecules. Functionality of the BSW and BSSW modes is theoretically described by dispersion relations, field confinements, and simulated refractive index shifts within the structure. The theoretical results are experimentally verified by detecting two different small chemical molecules and one large 40 base DNA oligonucleotide. The PSi-BSW/BSSW structure is benchmarked against current porous silicon technology and is shown to have a 6-fold higher sensitivity in detecting large molecules and a 33% improvement in detecting small molecules. This is the first report of a grating-coupled BSW biosensor and the first report of a BSSW propagating mode. © 2013 Published by Elsevier B.V.

Regional Assessment of Human Fecal Contamination in Southern California Coastal Drainages

PubMed Central

Cao, Yiping; Raith, Meredith R.; Smith, Paul D.; Griffith, John F.; Weisberg, Stephen B.; Schriewer, Alexander; Sheldon, Andrew; Crompton, Chris; Gregory, Jason; Guzman, Joe; Othman, Laila; Manasjan, Mayela; Choi, Samuel; Rapoport, Shana; Steele, Syreeta; Nguyen, Tommy; Yu, Xueyuan

2017-01-01

Host-associated genetic markers that allow for fecal source identification have been used extensively as a diagnostic tool to determine fecal sources within watersheds, but have not been used in routine monitoring to prioritize remediation actions among watersheds. Here, we present a regional assessment of human marker prevalence among drainages that discharge to the U.S. southern California coast. Approximately 50 samples were analyzed for the HF183 human marker from each of 22 southern California coastal drainages under summer dry weather conditions, and another 50 samples were targeted from each of 23 drainages during wet weather. The HF183 marker was ubiquitous, detected in all but two sites in dry weather and at all sites during wet weather. However, there was considerable difference in the extent of human fecal contamination among sites. Similar site ranking was produced regardless of whether the assessment was based on frequency of HF183 detection or site average HF183 concentration. However, site ranking differed greatly between dry and wet weather. Site ranking also differed greatly when based on enterococci, which do not distinguish between pollution sources, vs. HF183, which distinguishes higher risk human fecal sources from other sources, indicating the additional value of the human-associated marker as a routine monitoring tool. PMID:28777324

Regional Assessment of Human Fecal Contamination in Southern California Coastal Drainages.

PubMed

Cao, Yiping; Raith, Meredith R; Smith, Paul D; Griffith, John F; Weisberg, Stephen B; Schriewer, Alexander; Sheldon, Andrew; Crompton, Chris; Amenu, Geremew G; Gregory, Jason; Guzman, Joe; Goodwin, Kelly D; Othman, Laila; Manasjan, Mayela; Choi, Samuel; Rapoport, Shana; Steele, Syreeta; Nguyen, Tommy; Yu, Xueyuan

2017-08-04

Host-associated genetic markers that allow for fecal source identification have been used extensively as a diagnostic tool to determine fecal sources within watersheds, but have not been used in routine monitoring to prioritize remediation actions among watersheds. Here, we present a regional assessment of human marker prevalence among drainages that discharge to the U.S. southern California coast. Approximately 50 samples were analyzed for the HF183 human marker from each of 22 southern California coastal drainages under summer dry weather conditions, and another 50 samples were targeted from each of 23 drainages during wet weather. The HF183 marker was ubiquitous, detected in all but two sites in dry weather and at all sites during wet weather. However, there was considerable difference in the extent of human fecal contamination among sites. Similar site ranking was produced regardless of whether the assessment was based on frequency of HF183 detection or site average HF183 concentration. However, site ranking differed greatly between dry and wet weather. Site ranking also differed greatly when based on enterococci, which do not distinguish between pollution sources, vs. HF183, which distinguishes higher risk human fecal sources from other sources, indicating the additional value of the human-associated marker as a routine monitoring tool.

Detection of subsurface-intensified eddies from observations of the sea-surface: a case study for Mediterranean Water Eddies in a long-term high-resolution simulation

NASA Astrophysics Data System (ADS)

Ciani, Daniele; Carton, Xavier; Barbosa Aguiar, Ana Claudia; Peliz, Alvaro; Bashmachnikov, Igor; Ienna, Federico; Chapron, Bertrand

2017-04-01

Subsurface-intensified eddies are ubiquitous in the world ocean. They can be generated by exchanges of water masses between semi-enclosed evaporation basins and the open ocean or by deep convection. Past and recent studies have shown that these eddies are carriers of large amounts of heat and salt, that they are coherent over inter-annual timescales and that they can migrate for several thousands of miles from their origination areas towards the open ocean. Hence, subsurface-intensified eddies can influence the three-dimensional distribution of oceanic tracers at global scale. The synoptic knowledge of the eddies positions and mean pathways is then crucial for evaluating temperature and salinity budgets in the world ocean. At present day, satellite sensors constitute the ideal tool for the synoptic and global scale observations of the ocean. Since they only provide informations on the oceanic surface, we characterized the signatures that subsurface eddies generate at the sea-surface, to determine the extent to which they can be isolated from the surrounding surface turbulence and be considered as a trace of an underlying eddy. We studied the surface signature of subsurface-intensified anticyclones (Mediterranean Water Eddies - Meddies) in a realistic, long-term (20 years) and high resolution simulation (dx = 3 km) based on the ROMS model. The novelty and advantage of this approach is given by the simultaneous availability of the full 3D eddies characteristics, the ones of the background ocean and of the sea-surface (in terms of sea-surface height, temperature and salinity). This also allowed us to speculate on a synergy between different satellite observations for the automatic detection of subsurface eddies from space. The along trajectory properties and surface signatures of more than 90 long-lived Meddies were analyzed. We showed that the Meddies constantly generate positive anomalies in sea-surface height and that these anomalies are principally related to the Meddy potential vorticity structure at depth (around 1000 m below the sea-surface). Such anomalies were long-lived, mostly migrated exhibiting southwestward trajectories, their intensities were O(10 cm) and extended horizontally up to more than 300 km (around 1.5 times the Meddy diameter). On the other hand, the Meddies thermohaline surface signatures proved to be mostly dominated by the local surface conditions and their structure poorly correlated to the Meddy structure at depth (e.g. the Meddy volume-integrated salt and temperature content). These results point out that satellite altimetry is the most suitable approach to track subsurface-intensified eddies from observations of the sea-surface, also encouraging the use of future high-resolution altimetric observations (e.g. SWOT) to detect subsurface oceanic motions from satellite sensors.

Spectral contrast-enhanced optical coherence tomography for improved detection of tumor microvasculature and functional imaging of lymphatic drainage

NASA Astrophysics Data System (ADS)

SoRelle, Elliott D.; Liba, Orly; Sen, Debasish; de la Zerda, Adam

2017-03-01

Optical Coherence Tomography (OCT) is well-suited to study in vivo dynamics of blood circulation and lymphatic flow because of the technique's combination of rapid image acquisition, micron spatial resolution, and penetration depth in turbid tissues. However, OCT has been historically constrained by a dearth of contrast agents that are readily distinguished from the strong scattering intrinsic to biological tissues. In this study, we demonstrate large gold nanorods (LGNRs) as optimized contrast agents for OCT. LGNRs produce 32-fold greater backscattering than GNRs previously tested for contrast-enhanced OCT. Furthermore, LGNRs exhibit 110-fold stronger spectral signal than conventional GNRs when coupled with custom spectral detection algorithms. This signal enhancement enables picomolar OCT detection sensitivity in vivo and single-particle detection against optically-clear backgrounds. Moreover, the ability to synthesize LGNRs with tunable spectral peaks provides a viable platform for multiplexed imaging studies. To explore the advantages of LGNRs as OCT contrast agents, we implemented them for noninvasive 3D imaging of tumor blood supply and active lymphatic drainage in mice. Spectral detection of LGNRs enabled 100% improvement in imaging depth for detecting microvasculature (vessels 20 μm in diameter) in U87MG glioblastoma xenografts in mice pinnae. We also demonstrated our approach's ability to map the spatial dependence of lymph drainage and flow directionality within lymphatic capillaries. Using LGNRs with distinct spectra, we further identified the functional states of individual lymphatic valves in vivo. Thus, this approach provides a powerful new platform for functional imaging that may be extended for future molecular imaging studies with OCT.

An electromagnetic induction method for underground target detection and characterization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bartel, L.C.; Cress, D.H.

1997-01-01

An improved capability for subsurface structure detection is needed to support military and nonproliferation requirements for inspection and for surveillance of activities of threatening nations. As part of the DOE/NN-20 program to apply geophysical methods to detect and characterize underground facilities, Sandia National Laboratories (SNL) initiated an electromagnetic induction (EMI) project to evaluate low frequency electromagnetic (EM) techniques for subsurface structure detection. Low frequency, in this case, extended from kilohertz to hundreds of kilohertz. An EMI survey procedure had already been developed for borehole imaging of coal seams and had successfully been applied in a surface mode to detect amore » drug smuggling tunnel. The SNL project has focused on building upon the success of that procedure and applying it to surface and low altitude airborne platforms. Part of SNL`s work has focused on improving that technology through improved hardware and data processing. The improved hardware development has been performed utilizing Laboratory Directed Research and Development (LDRD) funding. In addition, SNL`s effort focused on: (1) improvements in modeling of the basic geophysics of the illuminating electromagnetic field and its coupling to the underground target (partially funded using LDRD funds) and (2) development of techniques for phase-based and multi-frequency processing and spatial processing to support subsurface target detection and characterization. The products of this project are: (1) an evaluation of an improved EM gradiometer, (2) an improved gradiometer concept for possible future development, (3) an improved modeling capability, (4) demonstration of an EM wave migration method for target recognition, and a demonstration that the technology is capable of detecting targets to depths exceeding 25 meters.« less

Detecting subsurface features and distresses of roadways and bridge decks with ground penetrating radar at traffic speed

NASA Astrophysics Data System (ADS)

Liu, Hao; Birken, Ralf; Wang, Ming L.

2017-04-01

This paper presents the detections of the subsurface features and distresses in roadways and bridge decks from ground penetrating radar (GPR) data collected at traffic speed. This GPR system is operated at 2 GHz with a penetration depth of 60 cm in common road materials. The system can collect 1000 traces a second, has a large dynamic range and compact packaging. Using a four channel GPR array, dense spatial coverage can be achieved in both longitudinal and transversal directions. The GPR data contains significant information about subsurface features and distresses resulting from dielectric difference, such as distinguishing new and old asphalt, identification of the asphalt-reinforced concrete (RC) interface, and detection of rebar in bridge decks. For roadways, the new and old asphalt layers are distinguished from the dielectric and thickness discontinuities. The results are complemented by surface images of the roads taken by a video camera. For bridge decks, the asphalt-RC interface is automatically detected by a cross correlation and Hilbert transform algorithms, and the layer properties (e.g., dielectric constant and thickness) can be identified. Moreover, the rebar hyperbolas can be visualized from the GPR B-scan images. In addition, the reflection amplitude from steel rebar can be extracted. It is possible to estimate the rebar corrosion level in concrete from the distribution of the rebar reflection amplitudes.

Detection of Subsurface Defects in Levees in Correlation to Weather Conditions Utilizing Ground Penetrating Radar

NASA Astrophysics Data System (ADS)

Martinez, I. A.; Eisenmann, D.

2012-12-01

Ground Penetrating Radar (GPR) has been used for many years in successful subsurface detection of conductive and non-conductive objects in all types of material including different soils and concrete. Typical defect detection is based on subjective examination of processed scans using data collection and analysis software to acquire and analyze the data, often requiring a developed expertise or an awareness of how a GPR works while collecting data. Processing programs, such as GSSI's RADAN analysis software are then used to validate the collected information. Iowa State University's Center for Nondestructive Evaluation (CNDE) has built a test site, resembling a typical levee used near rivers, which contains known sub-surface targets of varying size, depth, and conductivity. Scientist at CNDE have developed software with the enhanced capabilities, to decipher a hyperbola's magnitude and amplitude for GPR signal processing. With this enhanced capability, the signal processing and defect detection capabilities for GPR have the potential to be greatly enhanced. This study will examine the effects of test parameters, antenna frequency (400MHz), data manipulation methods (which include data filters and restricting the range of depth in which the chosen antenna's signal can reach), and real-world conditions using this test site (such as varying weather conditions) , with the goal of improving GPR tests sensitivity for differing soil conditions.

Sleep Deprivation Attack Detection in Wireless Sensor Network

NASA Astrophysics Data System (ADS)

Bhattasali, Tapalina; Chaki, Rituparna; Sanyal, Sugata

2012-02-01

Deployment of sensor network in hostile environment makes it mainly vulnerable to battery drainage attacks because it is impossible to recharge or replace the battery power of sensor nodes. Among different types of security threats, low power sensor nodes are immensely affected by the attacks which cause random drainage of the energy level of sensors, leading to death of the nodes. The most dangerous type of attack in this category is sleep deprivation, where target of the intruder is to maximize the power consumption of sensor nodes, so that their lifetime is minimized. Most of the existing works on sleep deprivation attack detection involve a lot of overhead, leading to poor throughput. The need of the day is to design a model for detecting intrusions accurately in an energy efficient manner. This paper proposes a hierarchical framework based on distributed collaborative mechanism for detecting sleep deprivation torture in wireless sensor network efficiently. Proposed model uses anomaly detection technique in two steps to reduce the probability of false intrusion.

Grid vs Mesh: The case of Hyper-resolution Modeling in Urban Landscapes

NASA Astrophysics Data System (ADS)

Grimley, L. E.; Tijerina, D.; Khanam, M.; Tiernan, E. D.; Frazier, N.; Ogden, F. L.; Steinke, R. C.; Maxwell, R. M.; Cohen, S.

2017-12-01

In this study, the relative performance of ADHydro and GSSHA was analyzed for a small and large rainfall event in an urban watershed called Dead Run near Baltimore, Maryland. ADHydro is a physics-based, distributed, hydrologic model that uses an unstructured mesh and operates in a high performance computing environment. The Gridded Surface/Subsurface Hydrological Analysis (GSSHA) model, which is maintained by the US Army Corps of Engineers, is a physics-based, distributed, hydrologic model that incorporates subsurface utilities and uses a structured mesh. A large portion of the work served as alpha-testing of ADHydro, which is under development by the CI-WATER modeling team at the University of Wyoming. Triangular meshes at variable resolutions were created to assess the sensitivity of ADHydro to changes in resolution and test the model's ability to handle a complicated urban routing network with structures present. ADHydro was compared with GSSHA which does not have the flexibility of an unstructured grid but does incorporate the storm drainage network. The modelled runoff hydrographs were compared to observed United States Geological Survey (USGS) stream gage data. The objective of this study was to analyze the effects of mesh type and resolution using ADHydro and GSSHA in simulations of an urban watershed.

Effects of manure-application practices on curli production by Escherichia coli transported through soil

NASA Astrophysics Data System (ADS)

Truhlar, A. M.; Salvucci, A. E.; Siler, J. D.; Richards, B. K.; Geohring, L.; Walter, M. T.; Hay, A. G.

2014-12-01

The release of Escherichia coli into the environment from untreated manure can pose a threat to human health. Environmental survival of E. coli has been linked to extracellular fibers called curli. We investigated the effect of manure management (surface application followed by incorporation versus immediate incorporation) on the relative abundance of curli-producing E. coli in subsurface drainage effluent. Samples were collected from three dairy farms. The proportion of curli-producing E. coli in the manure storage facilities was uniform across the farms. However, the abundance of curli-producing E. coli was much greater (P < 0.05) in the tile drains of farms performing surface application of manure than in the tile drain of the farm that incorporated manure. This field result was corroborated by controlled soil column experiments; the abundance of curli-producing E. coli in soil column effluents was greater (P < 0.05) when manure was surface-applied than when it was incorporated. Our findings suggest selection pressures resulting from the different manure application methods affected curli production by E. coli isolates transported through soil. Given the importance of curli production in pathogenesis, this work highlights the effect that manure management strategies may have on pathogenesis-associated phenotypes of bacteria in agricultural subsurface runoff.

Application of AMDS mortar as a treatment agent for arsenic in subsurface environment

NASA Astrophysics Data System (ADS)

Choi, J.; Lee, H.; Choi, U. K.; Yang, I. J.

2014-12-01

Among the treatment technologies available for As in soil and groundwater, adsorption or precipitation using acid mine drainage (AMD) sludge has become a promised technique because of high efficiency, inexpensiveness and simple to handling. The adsorbents were prepared by addition of Cement, Joomoonjin sand, fly ash, and Ca(OH)2 to air dry AMD sludge. In this work, the adsorption of As (III) and As (V) on AMDS mortar has been studied as a function of kinetic, pH, and initial arsenic concentration. Results of batch study showed that 75-90% of both As (III) and As (V) were removed at pH 7. Arsenic adsorption capacities were the highest at neutral pH condition and the adsorption equilibrium time reached in 7 days using AMDS mortar. Additionally, the adsorption kinetic process is expressed well by pseudo-second-order model. The adsorption capacities of AMDS mortar for As(III) and As(V) were found 19.04 and 30.75 mg g-1, respectively. The results of As (III) adsorption isotherms were fitted well to the Freundlich model. Moreover, As (V) adsorption isotherms were fitted well to the Langmuir model rather than Freundlich model. Based on experimental results in this study, we could conclude that AMDS mortar can be effectively used for arsenic removal agent from subsurface environment.

Modelingevapotranspirationina sub-tropical climate

USGS Publications Warehouse

Savabi, M.R.; Cochrane, T.A.; German, E.; Ikiz, C.; Cockshutt, N.

2007-01-01

Evapotranspiration (ET) loss is estimated at about 80-85% of annual precipitation in South Florida. Accurate prediction of ET is important during and beyond the implementation of the Comprehensive Everglades Restoration Plan (CERP). In the USDA's Everglades Agro-Hydrology Model (EAHM) the soil water intake is linked with the soil water redistribution, soil evaporation, plant transpiration, subsurface lateral flow and subsurface drainage to calculate daily root zone soil water content. Hydrometeorological data from three sites with different soil moisture content and vegetal cover were used to evaluate the EAHM ET routine. In general, the EAHM water balance sub-model simulated the daily ET with acceptable accuracy in the area with standing water (Everglades) while using the Penman method. However, in the area with grass cover, there was a discrepancy between the model simulated and measured ET using either the Penman or the Priestley-Taylor method. The results indicated that in the region with two distinct climate patterns: dry (low humidity, more wind, and less precipitation) and wet (high humidity, less wind and more rainfall) such as South Florida, a combination method like Penman should be used for prediction of daily ET. However, in order to improve the predictability of the ET methods, information about surface albedo is needed for land surfaces with grass vegetation during the growing season.

Sub-Surface Windscreen for the Measurement of Outdoor Infrasound

NASA Technical Reports Server (NTRS)

Shams, Qamar A.; Burkett, Cecil G., Jr.; Comeaux, Toby; Zuckerwar, Allan J.; Weistroffer, George R.

2008-01-01

A windscreen has been developed that features two advantages favorable for the measurement of outdoor infrasound. First, the sub-surface location, with the top of the windscreen flush with the ground surface, minimizes the mean velocity of the impinging wind. Secondly, the windscreen material (closed cell polyurethane foam) has a sufficiently low acoustic impedance (222 times that of air) and wall thickness (0.0127 m) to provide a transmission coefficient of nearly unity over the infrasonic frequency range (0-20 Hz). The windscreen, a tightly-sealed box having internal dimensions of 0.3048 x 0.3048 x 0.3556 m, contains a microphone, preamplifier, and a cable feed thru to an external power supply. Provisions are made for rain drainage and seismic isolation. A three-element array, configured as an equilateral triangle with 30.48 m spacing and operating continuously in the field, periodically receives highly coherent signals attributed to emissions from atmospheric turbulence. The time delays between infrasonic signals received at the microphones permit determination of the bearing and elevation of the sources, which correlate well with locations of pilot reports (PIREPS) within a 320 km radius about the array. The test results are interpreted to yield spectral information on infrasonic emissions from clear air turbulence.

Early Mars: A regional assessment of denudation chronology

NASA Technical Reports Server (NTRS)

Maxwell, T. A.; Craddock, R. A.

1993-01-01

Within the oldest highland units on Mars, the record of crater degradation indicates that fluvial resurfacing was responsible for modifying the Noachian through middle-Hesperian crater population. Based on crater frequency in the Noachian cratered terrain, age/elevation relations suggest that the highest exposures of Noachian dissected and plateau units became stabilized first, followed by successively lower units. In addition, studies of drainage networks indicate that the frequency of Noachian channels is greatest at high elevations. Together, these observations provide strong evidence of atmospheric involvement in volatile recycling. The long time period of crater modification also suggests that dendritic highland drainage was not simply the result of sapping by release of juvenile water, because the varied geologic units as well as the elevation dependence of stability ages makes it unlikely that subsurface recycling could provide a continuous supply of water for channel formation by sapping. While such geomorphic constraints on volatile history have been established by crater counts and stratigraphic relations using the 1:2M photomosaic series, photogeologic age relationships at the detailed level are needed to establish a specific chronology of erosion and sedimentation. Age relations for discrete erosional slopes and depositional basins will help refine ages of fluvial degradation, assess effectiveness of aeolian processes, and provide a regional chronology of fluvial events.

The interaction of natural organic matter with iron in a wetland (Tennessee Park, Colorado) receiving acid mine drainage

USGS Publications Warehouse

Peiffer, Stefan; Walton-Day, Katherine; Macalady, Donald L.

1999-01-01

Pore water from a wetland receiving acid mine drainage was studied for its iron and natural organic matter (NOM) geochemistry on three different sampling dates during summer 1994. Samples were obtained using a new sampling technique that is based on screened pipes of varying length (several centimeters), into which dialysis vessels can be placed and that can be screwed together to allow for vertical pore-water sampling. The iron concentration increased with time (through the summer) and had distinct peaks in the subsurface. Iron was mainly in the ferrous form; however, close to the surface, significant amounts of ferric iron (up to 40% of 2 mmol L-1 total iron concentration) were observed. In all samples studied, iron was strongly associated with NOM. Results from laboratory experiments indicate that the NOM stabilizes the ferric iron as small iron oxide colloids (able to pass a 0.45μm dialysis membrane). We hypothesize that, in the pore water of the wetland, the high NOM concentrations (>100 mg C L-1) allow formation of such colloids at the redoxcline close to the surface and at the contact zone to the adjacent oxic aquifer. Therefore, particle transport along flow paths and resultant export of ferric iron from the wetland into ground water might be possible.

Effect of Agricultural Practices on Hydrology and Water Chemistry in a Small Irrigated Catchment, Yakima River Basin, Washington

USGS Publications Warehouse

McCarthy, Kathleen A.; Johnson, Henry M.

2009-01-01

The role of irrigation and artificial drainage in the hydrologic cycle and the transport of solutes in a small agricultural catchment in central Washington's Yakima Valley were explored using hydrologic, chemical, isotopic, age-dating, and mineralogical data from several environmental compartments, including stream water, ground water, overland flow, and streambed pore water. A conceptual understanding of catchment hydrology and solute transport was developed and an inverse end-member mixing analysis was used to further explore the effects of agriculture in this small catchment. The median concentrations of major solutes and nitrates were similar for the single field site and for the catchment outflow site, indicating that the net effects of transport processes for these constituents were similar at both scales. However, concentrations of nutrients were different at the two sites, suggesting that field-scale variations in agricultural practices as well as nearstream and instream biochemical processes are important components of agricultural chemical transformation and transport in this catchment. This work indicates that irrigation coupled with artificial drainage networks may exacerbate the ecological effects of agricultural runoff by increasing direct connectivity between fields and streams and minimizing potentially mitigating effects (denitrification and dilution, for example) of longer subsurface pathways.

Shallow and Deep Groundwater Contributions to Ephemeral Streamflow Generation

NASA Astrophysics Data System (ADS)

Zimmer, M. A.; McGlynn, B. L.

2016-12-01

Our understanding of streamflow generation processes in low relief, humid landscapes is limited. To address this, we utilized an ephemeral-to-intermittent drainage network in the Piedmont region of the United States to gain new understanding about the drivers of ephemeral streamflow generation, stream-groundwater interactions, and longitudinal expansion and contraction of the stream network. We used hydrometric and chemical data collected within zero through second order catchments to characterize streamflow and overland, shallow soil, and deep subsurface flow across landscape positions. Results showed bi-directionality in stream-groundwater gradients that were dependent on catchment storage state. This led to annual groundwater recharge magnitudes that were similar to annual streamflow. Perched shallow and deep water table contributions shifted dominance with changes in catchment storage state, producing distinct stream hydrograph recession constants. Active channel length versus runoff followed a consistent relationship independent of storage state, but exhibited varying discharge-solute hysteresis directions. Together, our results suggest that temporary streams can act as both important groundwater recharge and discharge locations across the landscape, especially in this region where ephemeral drainage densities are among the highest recorded. Our results also highlight that the internal catchment dynamics that generate temporary streams play an important role in dictating biogeochemical fluxes at the landscape scale.

User’s guide to the collection and analysis of tree cores to assess the distribution of subsurface volatile organic compounds

USGS Publications Warehouse

Vroblesky, Don A.

2008-01-01

Analysis of the volatile organic compound content of tree cores is an inexpensive, rapid, simple approach to examining the distribution of subsurface volatile organic compound contaminants. The method has been shown to detect several volatile petroleum hydrocarbons and chlorinated aliphatic compounds associated with vapor intrusion and ground-water contamination. Tree cores, which are approximately 3 inches long, are obtained by using an increment borer. The cores are placed in vials and sealed. After a period of equilibration, the cores can be analyzed by headspace analysis gas chromatography. Because the roots are exposed to volatile organic compound contamination in the unsaturated zone or shallow ground water, the volatile organic compound concentrations in the tree cores are an indication of the presence of subsurface volatile organic compound contamination. Thus, tree coring can be used to detect and map subsurface volatile organic compound contamination. For comparison of tree-core data at a particular site, it is important to maintain consistent methods for all aspects of tree-core collection, handling, and analysis. Factors affecting the volatile organic compound concentrations in tree cores include the type of volatile organic compound, the tree species, the rooting depth, ground-water chemistry, the depth to the contaminated horizon, concentration differences around the trunk related to variations in the distribution of subsurface volatile organic compounds, concentration differences with depth of coring related to volatilization loss through the bark and possibly other unknown factors, dilution by rain, seasonal influences, sorption, vapor-exchange rates, and within-tree volatile organic compound degradation.

Understanding Subsurface Flow Mechanisms by Studying Recession Flow Curves

NASA Astrophysics Data System (ADS)

patnaik, S.; Biswal, B.; D, N.

2013-12-01

The recession flows offer valuable information on the subsurface systems of the drainage which cannot be observed due to technological limitations. Many analytical frameworks have been proposed in the past to analyze recession flow curves assess. Among them the most widely used one is Brutsaert-Neiber method of expressing negative time derivative of Q (discharge at the basin outlet at time t), -dQ/dt, as a function of Q itself, which eliminates the need of finding a reference time. Typically, basins across geographical regions display a power law relationship of the type: -dQ/dt = kQ^α. For a particular basin, the exponent α remains fairly constant recession events while the coefficient k varies greatly from one recession event to another, indicating the dynamic nature -dQ/dt-Q relationship. Recent observations show that subsurface storage in a basin mainly controls the dynamic parameter k. As subsurface water takes long time to fully drain, k of a recession event can also be influenced by the storage that occurred during the past rainfall events. We indirectly analyze the effect of past storage on recession flow by considering past streamflow as a proxy of past storage. A stronger relationship implies that the basin is able to store water for longer duration, and vice versa. In this study, we used streamflow data from 388 USGS basins that are relatively unaffected by human activities to find out the factors that affect the relationship between the power law correlation (R^2_PN) between past discharge and k, where the subscript N is the number of days of past streamflow observations considered for the recession event. For most of the basins R^2_PN decreases with N. We then selected 18 physical and climatological parameters for each study basin and investigated how they influence the value of R^2_PN for each N. We followed multiple linear regression method and found that R^2_PN is strongly influenced by the selected parameters (R^2 = 0.58) for N =30 days. We also employed principal component analysis to identify influence of individual parameters on R^2_PN. Our findings strongly indicate the possibility of understanding subsurface flow mechanism by merely analyzing recession flow curves.

Genetic structure of Columbia River redband trout populations in the Kootenai River drainage, Montana, revealed by microsatellite and allozyme loci

USGS Publications Warehouse

Knudsen, K.-L.; Muhlfeld, C.C.; Sage, G.K.; Leary, R.F.

2002-01-01

We describe the genetic divergence among 10 populations of redband trout Oncorhynchus mykiss gairdneri from the upper Columbia River drainage. Resident redband trout from two watersheds in the Kootenai River drainage and hatchery stocks of migratory Kamloops redband trout from Kootenay Lake, British Columbia, were analyzed using allele frequency data from microsatellite and allozyme loci. The Kamloops populations have significantly different allele frequencies from those of the Kootenai River drainage. Of the total genetic variation detected in the resident redband trout, 40.7% (microsatellites) and 15.5% (allozymes) were due to differences between populations from the two Kootenai River watersheds. The divergence among populations within each watershed, however, was less than 3.5% with both techniques. Our data indicate that watershed-specific broodstocks of redband trout are needed by fisheries managers for reintroduction or the supplementation of populations at risk of extinction.

Rapid reaccumulation of hydrometra after drainage at embryo transfer in patients with hydrosalpinx.

PubMed

Hinckley, Mary D; Milki, Amin A

2003-11-01

To report the occurrence and management of hydrometra at the time of scheduled embryo transfer in two patients who underwent drainage of hydrosalpinges at oocyte retrieval. Case report. University IVF clinic. Two patients with hydrosalpinges visible on ultrasonography who deferred tubal surgery. Although no fluid was seen at the time of oocyte retrieval, hydrometra was noticed and drained before planned embryo transfer (ET). Reoccurrence of hydrometra after drainage. Rapid reaccumulation of hydrometra despite drainage was seen in both patients, one of whom had reoccurrence in 1 hour. Embryo transfer was deferred until after tubal surgery, and all embryos were cryopreserved. In patients with hydrosalpinges, ultrasonography before ET is useful to detect newly developed hydrometra. Aspiration of the uterine fluid is unlikely to help because of rapid reaccumulation of hydrometra. Cryopreservation of the embryos for future transfer after the hydrosalpinx is removed or ligated is recommended.

Growth of microorganisms in Martian-like shallow subsurface conditions: laboratory modelling

NASA Astrophysics Data System (ADS)

Pavlov, A. K.; Shelegedin, V. N.; Vdovina, M. A.; Pavlov, A. A.

2010-01-01

Low atmospheric pressures on Mars and the lack of substantial amounts of liquid water were suggested to be among the major limiting factors for the potential Martian biosphere. However, large amounts of ice were detected in the relatively shallow subsurface layers of Mars by the Odyssey Mission and when ice sublimates the water vapour can diffuse through the porous surface layer of the soil. Here we studied the possibility for the active growth of microorganisms in such a vapour diffusion layer. Our results showed the possibility of metabolism and the reproduction of non-extremophile terrestrial microorganisms (Vibrio sp.) under very low (0.01-0.1 mbar) atmospheric pressures in a Martian-like shallow subsurface regolith.

4D ground penetrating radar measurements as non-invasive means for hydrological process investigation

NASA Astrophysics Data System (ADS)

Jackisch, Conrad; Allroggen, Niklas

2017-04-01

The missing vision into the subsurface appears to be a major limiting factor for our hydrological process understanding and theory development. Today, hydrology-related sciences have collected tremendous evidence for soils acting as drainage network and retention stores simultaneously in structured and self-organising domains. However, our present observation technology relies mainly on point-scale sensors, which integrate over a volume of unknown structures and is blind for their distribution. Although heterogeneity is acknowledged at all scales, it is rarely seen as inherent system property. At small scales (soil moisture probe) and at large scales (neutron probe) our measurements leave quite some ambiguity. Consequently, spatially and temporally continuous measurement of soil water states is essential for advancing our understanding and development of subsurface process theories. We present results from several irrigation experiments accompanied by 2D and 3D time-lapse GPR for the development of a novel technique to visualise and quantify water dynamics in the subsurface. Through the comparison of TDR, tracer and gravimetric measurement of soil moisture it becomes apparent that all sensor-based techniques are capable to record temporal dynamics, but are challenged to precisely quantify the measurements and to extrapolate them in space. At the same time excavative methods are very limited in temporal and spatial resolution. The application of non-invasive 4D GPR measurements complements the existing techniques and reveals structural and temporal dynamics simultaneously. By consequently increasing the density of the GPR data recordings in time and space, we find means to process the data also in the time-dimension. This opens ways to quantitatively analyse soil water dynamics in complex settings.

Use of electromagnetic induction methods to monitor remediation at the University of Connecticut landfill: 2004–2011

USGS Publications Warehouse

Johnson, Carole D.; White, Eric A.; Joesten, Peter K.

2012-01-01

Time‐lapse geophysical surveys using frequency‐domain electromagnetics (FDEM) can indirectly measure time‐varying hydrologic parameters such as fluid saturation or solute concentration. Monitoring of these processes provides insight into aquifer properties and the effectiveness of constructed controls (such as leachate interceptor trenches), as well as aquifer responses to natural or induced stresses. At the University of Connecticut landfill, noninvasive, electromagnetic induction (EMI) methods were used to monitor changes in subsurface electrical conductivity that were related to the landfill‐closure activities. After the landfill was closed, EMI methods were used to monitor changes in water saturation and water quality. As part of a long‐term monitoring plan to observe changes associated with closure, redevelopment, and remediation of the former landfill, EMI data were collected to supplement information from groundwater samples collected in wells to the south and north of the landfill. In comparison to single‐point measurements that could have been collected by conventional installation of additional monitoring wells, the EMI methods provided increased spatial coverage, and were less invasive and therefore less destructive to the wetland north of the landfill. To monitor effects of closure activities on the subsurface conductivity, EMI measurements were collected from 2004 to 2011 along discrete transects north and south of the landfill prior to, during, and after the landfill closure. In general, the results indicated an overall decline in subsurface electrical conductivity with time and with distance from the former landfill. This decline in electrical conductivity indicated that the closure and remediation efforts reduced the amount of leachate that originated from the landfill and that entered the drainages to the north and south of the landfill.

Continuous 'Passive' Registration of Non-Point Contaminant Loads Via Agricultural Subsurface Drain Tubes

NASA Astrophysics Data System (ADS)

Rozemeijer, J.; Jansen, S.; de Jonge, H.; Lindblad Vendelboe, A.

2014-12-01

Considering their crucial role in water and solute transport, enhanced monitoring and modeling of agricultural subsurface tube drain systems is important for adequate water quality management. For example, previous work in lowland agricultural catchments has shown that subsurface tube drain effluent contributed up to 80% of the annual discharge and 90-92% of the annual NO3 loads from agricultural fields towards the surface water. However, existing monitoring techniques for flow and contaminant loads from tube drains are expensive and labor-intensive. Therefore, despite the unambiguous relevance of this transport route, tube drain monitoring data are scarce. The presented study aimed developing a cheap, simple, and robust method to monitor loads from tube drains. We are now ready to introduce the Flowcap that can be attached to the outlet of tube drains and is capable of registering total flow, contaminant loads, and flow-averaged concentrations. The Flowcap builds on the existing SorbiCells, a modern passive sampling technique that measures average concentrations over longer periods of time (days to months) for various substances. By mounting SorbiCells in our Flowcap, a flow-proportional part of the drain effluent is sampled from the main stream. Laboratory testing yielded good linear relations (R-squared of 0.98) between drainage flow rates and sampling rates. The Flowcap was tested in practice for measuring NO3 loads from two agricultural fields and one glasshouse in the Netherlands. The Flowcap registers contaminant loads from tube drains without any need for housing, electricity, or maintenance. This enables large-scale monitoring of non-point contaminant loads via tube drains, which would facilitate the improvement of contaminant transport models and would yield valuable information for the selection and evaluation of mitigation options to improve water quality.

The influence of Critical Zone structure on runoff paths, seasonal water storage, and ecosystem composition

NASA Astrophysics Data System (ADS)

Hahm, W. J.; Dietrich, W. E.; Rempe, D.; Dralle, D.; Dawson, T. E.; Lovill, S.; Bryk, A.

2017-12-01

Understanding how subsurface water storage mediates water availability to ecosystems is crucial for elucidating linkages between water, energy, and carbon cycles from local to global scales. Earth's Critical Zone (the CZ, which extends from the top of the vegetation canopy downward to fresh bedrock) includes fractured and weathered rock layers that store and release water, thereby contributing to ecosystem water supplies, and yet are not typically represented in land-atmosphere models. To investigate CZ structural controls on water storage dynamics, we intensively studied field sites in a Mediterranean climate where winter rains arrive months before peak solar energy availability, resulting in strong summertime ecosystem reliance on stored subsurface water. Intra-hillslope and catchment-wide observations of CZ water storage capacity across a lithologic boundary in the Franciscan Formation of the Northern California Coast Ranges reveal large differences in the thickness of the CZ and water storage capacity that result in a stark contrast in plant community composition and stream behavior. Where the CZ is thick, rock moisture storage supports forest transpiration and slow groundwater release sustains baseflow and salmon populations. Where the CZ is thin, limited water storage is used by an oak savanna ecosystem, and streams run dry in summer due to negligible hillslope drainage. At both sites, wet season precipitation replenishes the dynamic storage deficit generated during the summer dry season, with excess winter rains exiting the watersheds via storm runoff as perched groundwater fracture flow at the thick-CZ site and saturation overland flow at the thin-CZ site. Annual replenishment of subsurface water storage even in severe drought years may lead to ecosystem resilience to climatic perturbations: during the 2011-2015 drought there was not widespread forest die-off in the study area.

Interpretation of Data from Uphole Refraction Surveys

DTIC Science & Technology

1980-06-01

Seismic refraction Seismic refraction method Seismic surveys Subsurface exploration ""-. 20, AI0SrRACT -(CmtuamU 00MvaO eL If naaaaamr and Identlfyby...by the presence of subsurface cavities and large cavities are identifiable, the sensitivity of the method is marginal for practical use in cavity...detection. Some cavities large enough to be of engineering signifi- cance (e.g., a tunnel of h-m diameter) may be practically undetectable by this method

Infrared emission contrast for the visualization of subsurface graphical features in artworks

NASA Astrophysics Data System (ADS)

Mercuri, Fulvio; Paoloni, Stefano; Cicero, Cristina; Zammit, Ugo; Orazi, Noemi

2018-03-01

In this paper a method is presented based on the use of active infrared thermography for the detection of subsurface graphical features in artworks. A theoretical model for the thermographic signal describing the physical mechanisms which allow the identification of the buried features has been proposed and thereafter it has been applied to the analysis of the results obtained on specifically made test samples. It is shown that the proposed model predictions adequately describe the experimental results obtained on the test samples. A comparative analysis between the proposed technique and infrared reflectography is also presented. The comparison shows that active thermography can be more effective in the detection of features buried below infrared translucent layers and, in addition, that it can provide information about the depth of the detected features, particularly in highly IR diffusing materials.

Soil and Water Pollution in a Banana Production Region in Tropical Mexico

PubMed Central

Ramos, Franzisco Que; de J. Bastidas-Bastidas, Pedro; Díaz-González, Gilberto; Bello-Mendoza, Ricardo; Huerta-Lwanga, Esperanza; Ruiz-Suárez, Luz E.

2010-01-01

The effects of abundant Mancozeb (Mn, Zn—bisdithiocarbamate) applications (2.5 kg ha−1week−1 for 10 years) on soil and surface-, subsurface- and groundwater pollution were monitored in a banana production region of tropical Mexico. In soils, severe manganese accumulation was observed, wheras the main metabolite ethylenethiourea was near the detection limit. Surface and subsurface water was highly polluted with ethylenethiourea, the main metabolite of Mancozeb (22.5 and 4.3 μg L−1, respectively), but not with manganese. In deep ground water, no ethylenethiourea was detected. The level of pollution in the region presents a worrisome risk for aquatic life and for human health. PMID:20734023

Soil and water pollution in a banana production region in tropical Mexico.

PubMed

Geissen, Violette; Ramos, Franzisco Que; de J Bastidas-Bastidas, Pedro; Díaz-González, Gilberto; Bello-Mendoza, Ricardo; Huerta-Lwanga, Esperanza; Ruiz-Suárez, Luz E

2010-10-01

The effects of abundant Mancozeb (Mn, Zn-bisdithiocarbamate) applications (2.5 kg ha⁻¹week⁻¹ for 10 years) on soil and surface-, subsurface- and groundwater pollution were monitored in a banana production region of tropical Mexico. In soils, severe manganese accumulation was observed, wheras the main metabolite ethylenethiourea was near the detection limit. Surface and subsurface water was highly polluted with ethylenethiourea, the main metabolite of Mancozeb (22.5 and 4.3 μg L⁻¹, respectively), but not with manganese. In deep ground water, no ethylenethiourea was detected. The level of pollution in the region presents a worrisome risk for aquatic life and for human health.

Nondestructive evaluation of structural ceramics by photoacoustic microscopy

NASA Technical Reports Server (NTRS)

Khandelwal, Pramod K.

1987-01-01

A photoacoustic microscopy (PAM) digital imaging system was developed and utilized to characterize silicon nitride material at the various stages of the ceramic fabrication process. Correlation studies revealed that photoacoustic microscopy detected failure initiating defects in substantially more specimens than microradiography and ultrasonic techniques. Photoacoustic microscopy detected 10 to 100 micron size surface and subsurface pores and inclusions, respectively, up to 80 microns below the interrogating surface in machined sintered silicon nitride. Microradiography detected 50 micron diameter fracture controlling pores and inclusions. Subsurface holes were detected up to a depth of 570 microns and 1.00 mm in sintered silicon nitride and silicon carbide, respectively. Seeded voids of 20 to 30 micron diameters at the surface and 50 microns below the interrogating surface were detected by photoacoustic microscopy and microradiography with 1 percent X-ray thickness sensitivity. Tight surface cracks of 96 micron length x 48 micron depth were detected by photoacoustic microscopy. PAM volatilized and removed material in the green state which resulted in linear shallow microcracks after sintering. This significantly limits the use of PAM as an in-process NDE technique.

Hydrodynamic model of cells for designing systems of urban groundwater drainage

NASA Astrophysics Data System (ADS)

Zimmermann, Eric; Riccardi, Gerardo

2000-08-01

An improved mathematical hydrodynamic quasi-two-dimensional model of cells, CELSUB3, is presented for simulating drainage systems that consist of pumping well fields or subsurface drains. The CELSUB3 model is composed of an assemblage of algorithms that have been developed and tested previously and that simulate saturated flow in porous media, closed conduit flow, and flow through pumping stations. A new type of link between aquifer cells and drainage conduits is proposed. This link is verified in simple problems with well known analytical solutions. The correlation between results from analytical and mathematical solutions was considered satisfactory in all cases. To simulate more complex situations, the new proposed version, CELSUB3, was applied in a project designed to control the water-table level within a sewer system in Chañar Ladeado Town, Santa Fe Province, Argentina. Alternative drainage designs, which were evaluated under conditions of dynamic recharge caused by rainfall in a critical year (wettest year for the period of record) and a typical year, are briefly described. After analyzing ten alternative designs, the best technical-economic solution is a subsurface drainage system of closed conduits with pumping stations and evacuation channels. Résumé. Un modèle hydrodynamique perfectionné de cellules en quasi 2D, CELSUB3, est présenté dans le but de simuler des systèmes de drainage qui consistent en des champs de puits de pompage ou de drains souterrains. Le modèle CELSUB3 est composé d'un assemblage d'algorithmes développés et testés précédemment et qui simulent des écoulements en milieu poreux saturé, en conduites et dans des stations de pompage. Un nouveau type de lien entre des cellules d'aquifères et des drains est proposé. Ce lien est vérifié dans des problèmes simples dont les solutions analytiques sont bien connues. La corrélation entre les résultats des solutions analytiques et des solutions mathématiques a été considérée comme satisfaisante dans tous les cas. Afin de simuler des situations plus complexes, la nouvelle version proposée, CELSUB3, a été mise en œuvre dans un projet destiné à contrôler le niveau de la nappe à l'intérieur d'un système d'égouts, dans la ville de Chaar Ladeado (province de Santa Fe, Argentine). Différentes organisations du projet de drainage, qui ont été testées pour des conditions de recharge dynamique causées par la pluie au cours d'une année critique (la plus humide de la chronique disponible) et une année typique, sont brièvement décrites. Après analyse de dix organisations différentes, la meilleure solution technico-économique retenue est un système de drainage souterrain de conduites avec des stations de pompage et des canaux d'évacuation. Resumen. Se presenta un modelo matemático hidrodinámico cuasi-bidimensional de celdas, CELSUB3, apto para la simulación integral de sistemas de drenaje subterráneo basados en campos de bombeo o drenes subsuperficiales. El modelo de simulación presenta un ensamble de algoritmos, previamente desarrollados y testeados, que representan al escurrimiento a través del medio poroso saturado, escurrimiento en conducciones cerradas, estaciones de bombeo, etc. En la estructura del modelo se propone un nuevo tipo de vinculación entre celdas acuíferas y conductos de drenaje, la cual es verificada en problemas simples con solución analítica conocida arrojando, en todos los casos, resultados satisfactorios. Abordando situaciones más complejas, la nueva versión propuesta fue aplicada en un proyecto de control de niveles freáticos que acompaña un sistema de conductos cloacales, en la localidad de Chañar Ladeado, Santa Fe, Argentina. Se describen las alternativas de drenaje consideradas las cuales fueron evaluadas bajo recargas dinámicas provocadas por años críticamente lluviosos y en situaciones típicas. Los resultados derivados permitieron definir, tras analizar una decena de proyectos alternativos, la mejor solución técnico-económica consistente en un sistema de drenes subterráneos, estaciones de bombeo y canales de evacuación.

Mars: Noachian hydrology by its statistics and topology

NASA Technical Reports Server (NTRS)

Cabrol, N. A.; Grin, E. A.

1993-01-01

Discrimination between fluvial features generated by surface drainage and subsurface aquifer discharges will provide clues to the understanding of early Mars' climatic history. Our approach is to define the process of formation of the oldest fluvial valleys by statistical and topological analyses. Formation of fluvial valley systems reached its highest statistical concentration during the Noachian Period. Nevertheless, they are a scarce phenomenom in Martian history, localized on the craterized upland, and subject to latitudinal distribution. They occur sparsely on Noachian geological units with a weak distribution density, and appear in reduced isolated surface (around 5 x 10(exp 3)(sq km)), filled by short streams (100-300 km length). Topological analysis of the internal organization of 71 surveyed Noachian fluvial valley networks also provides information on the mechanisms of formation.

Surface and subsurface cracks characteristics of single crystal SiC wafer in surface machining

NASA Astrophysics Data System (ADS)

Qiusheng, Y.; Senkai, C.; Jisheng, P.

2015-03-01

Different machining processes were used in the single crystal SiC wafer machining. SEM was used to observe the surface morphology and a cross-sectional cleavages microscopy method was used for subsurface cracks detection. Surface and subsurface cracks characteristics of single crystal SiC wafer in abrasive machining were analysed. The results show that the surface and subsurface cracks system of single crystal SiC wafer in abrasive machining including radial crack, lateral crack and the median crack. In lapping process, material removal is dominated by brittle removal. Lots of chipping pits were found on the lapping surface. With the particle size becomes smaller, the surface roughness and subsurface crack depth decreases. When the particle size was changed to 1.5µm, the surface roughness Ra was reduced to 24.0nm and the maximum subsurface crack was 1.2µm. The efficiency of grinding is higher than lapping. Plastic removal can be achieved by changing the process parameters. Material removal was mostly in brittle fracture when grinding with 325# diamond wheel. Plow scratches and chipping pits were found on the ground surface. The surface roughness Ra was 17.7nm and maximum subsurface crack depth was 5.8 µm. When grinding with 8000# diamond wheel, the material removal was in plastic flow. Plastic scratches were found on the surface. A smooth surface of roughness Ra 2.5nm without any subsurface cracks was obtained. Atomic scale removal was possible in cluster magnetorheological finishing with diamond abrasive size of 0.5 µm. A super smooth surface eventually obtained with a roughness of Ra 0.4nm without any subsurface crack.

Utilizing ERTS imagery to detect plant diseases and nutrient deficiencies, soil types and soil moisture levels

NASA Technical Reports Server (NTRS)

Parks, W. L. (Principal Investigator); Sewell, J. I.; Hilty, J. W.; Rennie, J. C.

1973-01-01

The author has identified the following significant results. The delineation of soil associations and detection of drainage patterns, erosion and sedimentation through the use of ERTS-1 imagery are shown. Corn blight and corn virus could not be detected from ERTS-1 and detection of forest composition was at a very low probability.

Tile drainage phosphorus loss with long-term consistent cropping systems and fertilization.

PubMed

Zhang, T Q; Tan, C S; Zheng, Z M; Drury, C F

2015-03-01

Phosphorus (P) loss in tile drainage water may vary with agricultural practices, and the impacts are often hard to detect with short-term studies. We evaluated the effects of long-term (≥43 yr) cropping systems (continuous corn [CC], corn-oats-alfalfa-alfalfa rotation [CR], and continuous grass [CS]) and fertilization (fertilization [F] vs. no-fertilization [NF]) on P loss in tile drainage water from a clay loam soil over a 4-yr period. Compared with NF, long-term fertilization increased concentrations and losses of dissolved reactive P (DRP), dissolved unreactive P (DURP), and total P (TP) in tile drainage water, with the increments following the order: CS > CR > CC. Dissolved P (dissolved reactive P [DRP] and dissolved unreactive P [DURP]) was the dominant P form in drainage outflow, accounting for 72% of TP loss under F-CS, whereas particulate P (PP) was the major form of TP loss under F-CC (72%), F-CR (62%), NF-CS (66%), NF-CC (74%), and NF-CR (72%). Dissolved unreactive P played nearly equal roles as DRP in P losses in tile drainage water. Stepwise regression analysis showed that the concentration of P (DRP, DURP, and PP) in tile drainage flow, rather than event flow volume, was the most important factor contributing to P loss in tile drainage water, although event flow volume was more important in PP loss than in dissolved P loss. Continuous grass significantly increased P loss by increasing P concentration and flow volume of tile drainage water, especially under the fertilization treatment. Long-term grasslands may become a significant P source in tile-drained systems when they receive regular P addition. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Temporal GPR Imaging of an Ethanol Release Within a Laboratory-Scaled Sand Tank

EPA Science Inventory

Within the last decade efforts in geophysical detection and monitoring of fossil fuel releases into the subsurface have shown increasing success, including the ability to geophysically detect and delineate enhanced and natural biodegradation and remediation activities. The subst...

Partitioning Tracer Test for Detection, Estimation, and Remediation Performance Assessment of Subsurface Nonaqueous Phase Liquids

NASA Astrophysics Data System (ADS)

Jin, Minquan; Delshad, Mojdeh; Dwarakanath, Varadarajan; McKinney, Daene C.; Pope, Gary A.; Sepehrnoori, Kamy; Tilburg, Charles E.; Jackson, Richard E.

1995-05-01

In this paper we present a partitioning interwell tracer test (PITT) technique for the detection, estimation, and remediation performance assessment of the subsurface contaminated by nonaqueous phase liquids (NAPLs). We demonstrate the effectiveness of this technique by examples of experimental and simulation results. The experimental results are from partitioning tracer experiments in columns packed with Ottawa sand. Both the method of moments and inverse modeling techniques for estimating NAPL saturation in the sand packs are demonstrated. In the simulation examples we use UTCHEM, a comprehensive three-dimensional, chemical flood compositional simulator developed at the University of Texas, to simulate a hypothetical two-dimensional aquifer with properties similar to the Borden site contaminated by tetrachloroethylene (PCE), and we show how partitioning interwell tracer tests can be used to estimate the amount of PCE contaminant before remedial action and as the remediation process proceeds. Tracer tests results from different stages of remediation are compared to determine the quantity of PCE removed and the amount remaining. Both the experimental (small-scale) and simulation (large-scale) results demonstrate that PITT can be used as an innovative and effective technique to detect and estimate the amount of residual NAPL and for remediation performance assessment in subsurface formations.

Partitioning tracer test for detection, estimation, and remediation performance assessment of subsurface nonaqueous phase liquids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jin, M.; Delshad, M.; Dwarakanath, V.

1995-05-01

In this paper we present a partitioning interwell tracer test (PITT) technique for the detection, estimation, and remediation performance assessment of the subsurface contaminated by nonaqueous phase liquids (NAPLs). We demonstrate the effectiveness of this technique by examples of experimental and simulation results. The experimental results are from partitioning tracer experiments in columns packed with Ottawa sand. Both the method of moments and inverse modeling techniques for estimating NAPL saturation in the sand packs are demonstrated. In the simulation examples we use UTCHEM, a comprehensive three-dimensional, chemical flood compositional simulator developed at the University of Texas, to simulate a hypotheticalmore » two-dimensional aquifer with properties similar to the Borden site contaminated by tetrachloroethylene (PCE), and we show how partitioning interwell tracer tests can be used to estimate the amount of PCE contaminant before remedial action and as the remediation process proceeds. Tracer test results from different stages of remediation are compared to determine the quantity of PCE removed and the amount remaining. Both the experimental (small-scale) and simulation (large-scale) results demonstrate that PITT can be used as an innovative and effective technique to detect and estimate the amount of residual NAPL and for remediation performance assessment in subsurface formations. 43 refs., 10 figs., 1 tab.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Qiusheng, Y., E-mail: qsyan@gdut.edu.cn; Senkai, C., E-mail: senkite@sina.com; Jisheng, P., E-mail: panjisheng@gdut.edu.cn

Different machining processes were used in the single crystal SiC wafer machining. SEM was used to observe the surface morphology and a cross-sectional cleavages microscopy method was used for subsurface cracks detection. Surface and subsurface cracks characteristics of single crystal SiC wafer in abrasive machining were analysed. The results show that the surface and subsurface cracks system of single crystal SiC wafer in abrasive machining including radial crack, lateral crack and the median crack. In lapping process, material removal is dominated by brittle removal. Lots of chipping pits were found on the lapping surface. With the particle size becomes smaller,more » the surface roughness and subsurface crack depth decreases. When the particle size was changed to 1.5µm, the surface roughness Ra was reduced to 24.0nm and the maximum subsurface crack was 1.2µm. The efficiency of grinding is higher than lapping. Plastic removal can be achieved by changing the process parameters. Material removal was mostly in brittle fracture when grinding with 325# diamond wheel. Plow scratches and chipping pits were found on the ground surface. The surface roughness Ra was 17.7nm and maximum subsurface crack depth was 5.8 µm. When grinding with 8000# diamond wheel, the material removal was in plastic flow. Plastic scratches were found on the surface. A smooth surface of roughness Ra 2.5nm without any subsurface cracks was obtained. Atomic scale removal was possible in cluster magnetorheological finishing with diamond abrasive size of 0.5 µm. A super smooth surface eventually obtained with a roughness of Ra 0.4nm without any subsurface crack.« less

Hydrologic connectivity: Quantitative assessments of hydrologic-enforced drainage structures in an elevation model

USGS Publications Warehouse

Poppenga, Sandra K.; Worstell, Bruce B.

2016-01-01

Elevation data derived from light detection and ranging present challenges for hydrologic modeling as the elevation surface includes bridge decks and elevated road features overlaying culvert drainage structures. In reality, water is carried through these structures; however, in the elevation surface these features impede modeled overland surface flow. Thus, a hydrologically-enforced elevation surface is needed for hydrodynamic modeling. In the Delaware River Basin, hydrologic-enforcement techniques were used to modify elevations to simulate how constructed drainage structures allow overland surface flow. By calculating residuals between unfilled and filled elevation surfaces, artificially pooled depressions that formed upstream of constructed drainage structure features were defined, and elevation values were adjusted by generating transects at the location of the drainage structures. An assessment of each hydrologically-enforced drainage structure was conducted using field-surveyed culvert and bridge coordinates obtained from numerous public agencies, but it was discovered the disparate drainage structure datasets were not comprehensive enough to assess all remotely located depressions in need of hydrologic-enforcement. Alternatively, orthoimagery was interpreted to define drainage structures near each depression, and these locations were used as reference points for a quantitative hydrologic-enforcement assessment. The orthoimagery-interpreted reference points resulted in a larger corresponding sample size than the assessment between hydrologic-enforced transects and field-surveyed data. This assessment demonstrates the viability of rules-based hydrologic-enforcement that is needed to achieve hydrologic connectivity, which is valuable for hydrodynamic models in sensitive coastal regions. Hydrologic-enforced elevation data are also essential for merging with topographic/bathymetric elevation data that extend over vulnerable urbanized areas and dynamic coastal regions.

Sternotomy or drainage for a hemopericardium after penetrating trauma: a randomized controlled trial.

PubMed

Nicol, Andrew J; Navsaria, Pradeep H; Hommes, Martijn; Ball, Chad G; Edu, Sorin; Kahn, Delawir

2014-03-01

To determine if stable patients with a hemopericardium detected after penetrating chest trauma can be safely managed with pericardial drainage alone. The current international practice is to perform a sternotomy and cardiac repair if a hemopericardium is detected after penetrating chest trauma. The experience in Cape Town, South Africa, on performing a mandatory sternotomy in hemodynamically stable patients was that a sternotomy was unnecessary and the cardiac injury, if present, had sealed. A single-center parallel-group randomized controlled study was completed. All hemodynamically stable patients with a hemopericardium confirmed at subxiphoid pericardial window (SPW), and no active bleeding, were randomized. The primary outcome measure was survival to discharge from hospital. Secondary outcomes were complications and postoperative hospital stay. Fifty-five patients were randomized to sternotomy and 56 to pericardial drainage and wash-out only. Fifty-one of the 55 patients (93%) randomized to sternotomy had either no cardiac injury or a tangential injury. There were only 4 patients with penetrating wounds to the endocardium and all had sealed. There was 1 death postoperatively among the 111 patients (0.9%) and this was in the sternotomy group. The mean intensive care unit (ICU) stay for a sternotomy was 2.04 days (range, 0-25 days) compared with 0.25 days (range, 0-2) for the drainage (P < 0.001). The estimated mean difference highlighted a stay of 1.8 days shorter in the ICU for the drainage group (95% CI: 0.8-2.7). Total hospital stay was significantly shorter in the SPW group (P < 0.001; 95% CI: 1.4-3.3). SPW and drainage is effective and safe in the stable patient with a hemopericardium after penetrating chest trauma, with no increase in mortality and a shorter ICU and hospital stay. (ClinicalTrials.gov Identifier: NCT00823160).

Evidence of Geobacter-associated phage in a uranium-contaminated aquifer

PubMed Central

Holmes, Dawn E; Giloteaux, Ludovic; Chaurasia, Akhilesh K; Williams, Kenneth H; Luef, Birgit; Wilkins, Michael J; Wrighton, Kelly C; Thompson, Courtney A; Comolli, Luis R; Lovley, Derek R

2015-01-01

Geobacter species may be important agents in the bioremediation of organic and metal contaminants in the subsurface, but as yet unknown factors limit the in situ growth of subsurface Geobacter well below rates predicted by analysis of gene expression or in silico metabolic modeling. Analysis of the genomes of five different Geobacter species recovered from contaminated subsurface sites indicated that each of the isolates had been infected with phage. Geobacter-associated phage sequences were also detected by metagenomic and proteomic analysis of samples from a uranium-contaminated aquifer undergoing in situ bioremediation, and phage particles were detected by microscopic analysis in groundwater collected from sediment enrichment cultures. Transcript abundance for genes from the Geobacter-associated phage structural proteins, tail tube Gp19 and baseplate J, increased in the groundwater in response to the growth of Geobacter species when acetate was added, and then declined as the number of Geobacter decreased. Western blot analysis of a Geobacter-associated tail tube protein Gp19 in the groundwater demonstrated that its abundance tracked with the abundance of Geobacter species. These results suggest that the enhanced growth of Geobacter species in the subsurface associated with in situ uranium bioremediation increased the abundance and activity of Geobacter-associated phage and show that future studies should focus on how these phages might be influencing the ecology of this site. PMID:25083935

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hoak, T.E.; Klawitter, A.L.

Fractured production trends in Piceance Basin Cretaceous-age Mesaverde Group gas reservoirs are controlled by subsurface structures. Because many of the subsurface structures are controlled by basement fault trends, a new interpretation of basement structure was performed using an integrated interpretation of Landsat Thematic Mapper (TM), side-looking airborne radar (SLAR), high altitude, false color aerial photography, gas and water production data, high-resolution aeromagnetic data, subsurface geologic information, and surficial fracture maps. This new interpretation demonstrates the importance of basement structures on the nucleation and development of overlying structures and associated natural fractures in the hydrocarbon-bearing section. Grand Valley, Parachute, Rulison, Plateau,more » Shire Gulch, White River Dome, Divide Creek and Wolf Creek fields all produce gas from fractured tight gas sand and coal reservoirs within the Mesaverde Group. Tectonic fracturing involving basement structures is responsible for development of permeability allowing economic production from the reservoirs. In this context, the significance of detecting natural fractures using the intergrated fracture detection technique is critical to developing tight gas resources. Integration of data from widely-available, relatively inexpensive sources such as high-resolution aeromagnetics, remote sensing imagery analysis and regional geologic syntheses provide diagnostic data sets to incorporate into an overall methodology for targeting fractured reservoirs. The ultimate application of this methodology is the development and calibration of a potent exploration tool to predict subsurface fractured reservoirs, and target areas for exploration drilling, and infill and step-out development programs.« less

Reactive Oxygen Species are Ubiquitous along Subsurface Redox Gradients

NASA Astrophysics Data System (ADS)

Nico, P. S.; Yuan, X.; Davis, J. A.; Dwivedi, D.; Williams, K. H.; Bhattacharyya, A.; Fox, P. M.

2016-12-01

Reactive oxygen species (hydroxyl radical, superoxide, hydrogen peroxide, etc.) are known to be important intermediates in many biological and earth system processes. They have been particularly well studied in the realms of atmospheric chemistry and aquatic photochemistry. However, recently there is increasing evidence that they are also present in impactful quantities in dark systems as a result of both biotic and abiotic reactions. Herein we will present a complementary suite of laboratory and field studies examining the presence and production of hydrogen peroxide under relevant subsurface conditions. The laboratory work examines the redox cycling between reduced organic matter, molecular oxygen, and Fe which results in not only the production of hydrogen peroxide and oxidation of organic functional groups but also the maintenance of steady-state concentration of Fe(II) under fully oxygenated aqueous conditions. The field studies involve three distinct locations, namely a shallow subsurface aquifer, a hyporheic zone redox gradient across a river meander, and a hillside shale seep. In all cases detectable quantities (tens of nanomolar) of hydrogen peroxide were measured. In general, concentrations peak under transitional redox conditions where there is the simultaneous presence of reduced Fe, organic matter, and at least trace dissolved oxygen. Many, but not all, of the observed dynamics in hydrogen peroxide production can be reproduced by a simple kinetic model representing the reactions between Fe, organic matter, and molecular oxygen, but many questions remain regarding the role of microorganisms and other redox active chemical species in determining the detected hydrogen peroxide concentrations. The consistent detection of hydrogen peroxide at these disparate locations supports the hypothesis that hydrogen peroxide, and by extension, the entire suite of reactive oxygen species are ubiquitous along subsurface redox gradients.

Detection of subsurface core-level shifts in Si 2p core-level photoemission from Si(111)-(1x1):As

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paggel, J.J.; Hasselblatt, M.; Horn, K.

1997-04-01

The (7 x 7) reconstruction of the Si(111) surface arises from a lowering energy through the reduction of the number of dangling bonds. This reconstruction can be removed by the adsorption of atoms such as hydrogen which saturate the dangling bonds, or by the incorporation of atoms, such as arsenic which, because of the additional electron it possesses, can form three bonds and a nonreactive lone pair orbital from the remaining two electrons. Core and valence level photoemission and ion scattering data have shown that the As atoms replace the top silicon atoms. Previous core level spectra were interpreted inmore » terms of a bulk and a single surface doublet. The authors present results demonstrate that the core level spectrum contains two more lines. The authors assign these to subsurface silicon layers which also experience changes in the charge distribution when a silicon atom is replaced by an arsenic atom. Subsurface core level shifts are not unexpected since the modifications of the electronic structure and/or of photohole screening are likely to decay into the bulk and not just to affect the top-most substrate atoms. The detection of subsurface components suggests that the adsorption of arsenic leads to charge flow also in the second double layer of the Si(111) surface. In view of the difference in atomic radius between As and Si, it was suggested that the (1 x 1): As surface is strained. The presence of charge rearrangement up to the second double layer implies that the atomic coordinates also exhibit deviations from their ideal Si(111) counterparts, which might be detected through a LEED I/V or photoelectron diffraction analysis.« less

The Astrobiology of the Subsurface: Caves and Rock Fracture Habitats on Earth, Mars and Beyond

NASA Technical Reports Server (NTRS)

Boston, Penelope J.

2017-01-01

The Astrobiology of the Subsurface: Exploring Cave Habitats on Earth, Mars and Beyond. We are using the spectacular underground landscapes of Earth caves as models for the subsurfaces of other planets. Caves have been detected on the Moon and Mars and are strongly suspected for other bodies in the Solar System including some of the ice covered Ocean Worlds that orbit gas giant planets. The caves we explore and study include many extreme conditions of relevance to planetary astrobiology exploration including high and low temperatures, gas atmospheres poisonous to humans but where exotic microbes can fluorish, highly acidic or salty fluids, heavy metals, and high background radiation levels. Some cave microorganisms eat their way through bedrock, some live in battery acid conditions, some produce unusual biominerals and rare cave formations, and many produce compounds of potential pharmaceutical and industrial significance. We study these unique lifeforms and the physical and chemical biosignatures that they leave behind. Such traces can be used to provide a Field Guide to Unknown Organisms for developing life detection space missions.

Comparison of soil thickness in a zero-order basin in the Oregon Coast Range using a soil probe and electrical resistivity tomography

USGS Publications Warehouse

Morse, Michael S.; Lu, Ning; Godt, Jonathan W.; Revil, André; Coe, Jeffrey A.

2012-01-01

Accurate estimation of the soil thickness distribution in steepland drainage basins is essential for understanding ecosystem and subsurface response to infiltration. One important aspect of this characterization is assessing the heavy and antecedent rainfall conditions that lead to shallow landsliding. In this paper, we investigate the direct current (DC) resistivity method as a tool for quickly estimating soil thickness over a steep (33–40°) zero-order basin in the Oregon Coast Range, a landslide prone region. Point measurements throughout the basin showed bedrock depths between 0.55 and 3.2 m. Resistivity of soil and bedrock samples collected from the site was measured for degrees of saturation between 40 and 92%. Resistivity of the soil was typically higher than that of the bedrock for degrees of saturation lower than 70%. Results from the laboratory measurements and point-depth measurements were used in a numerical model to evaluate the resistivity contrast at the soil-bedrock interface. A decreasing-with-depth resistivity contrast was apparent at the interface in the modeling results. At the field site, three transects were surveyed where coincident ground truth measurements of bedrock depth were available, to test the accuracy of the method. The same decreasing-with-depth resistivity trend that was apparent in the model was also present in the survey data. The resistivity contour of between 1,000 and 2,000 Ωm that marked the top of the contrast was our interpreted bedrock depth in the survey data. Kriged depth-to-bedrock maps were created from both the field-measured ground truth obtained with a soil probe and interpreted depths from the resistivity tomography, and these were compared for accuracy graphically. Depths were interpolated as far as 16.5 m laterally from the resistivity survey lines with root mean squared error (RMSE) = 27 cm between the measured and interpreted depth at those locations. Using several transects and analysis of the subsurface material properties, the direct current (DC) resistivity method is shown to be able to delineate bedrock depth trends within the drainage basin.

Watershed scale fungal community characterization along a pH gradient in a subsurface environment co-contaminated with uranium and nitrate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jasrotia, Puja; Green, Stefan; Canion, Andy

2014-01-01

The objective of this study was to characterize fungal communities in a subsurface environment co-contaminated with uranium and nitrate at the watershed scale, and to determine the potential contribution of fungi to contaminant transformation (nitrate attenuation). The abundance, distribution and diversity of fungi in subsurface groundwater samples were determined using quantitative and semi-quantitative molecular techniques, including quantitative PCR of eukaryotic SSU rRNA genes and pyrosequencing of fungal internal transcribed spacer (ITS) regions. Potential bacterial and fungal denitrification was assessed in sediment-groundwater slurries amended with antimicrobial compounds and in fungal pure cultures isolated from subsurface. Our results demonstrate that subsurface fungalmore » communities are dominated by members of the phylum Ascomycota, and a pronounced shift in fungal community composition occurs across the groundwater pH gradient at the field site, with lower diversity observed under acidic (pH < 4.5) conditions. Fungal isolates recovered from subsurface sediments were shown to reduce nitrate to nitrous oxide, including cultures of the genus Coniochaeta that were detected in abundance in pyrosequence libraries of site groundwater samples. Denitrifying fungal isolates recovered from the site were classified, and found to be distributed broadly within the phylum Ascomycota, and within a single genus within the Basidiomycota. Potential denitrification rate assays with sediment-groundwater slurries showed the potential for subsurface fungi to reduce nitrate to nitrous oxide under in situ acidic pH conditions.« less

Influence of bedrock topography on the runoff generation under use of ERT data

NASA Astrophysics Data System (ADS)

Kiese, Nina; Loritz, Ralf; Allroggen, Niklas; Zehe, Erwin

2017-04-01

Subsurface topography has been identified to play a major role for the runoff generation in different hydrological landscapes. Sinks and ridges in the bedrock can control how water is stored and transported to the stream. Detecting the subsurface structure is difficult and laborious and frequently done by auger measurements. Recently, the geophysical imaging of the subsurface by Electrical Resistivity Tomography (ERT) gained much interest in the field of hydrology, as it is a non-invasive method to collect information on the subsurface characteristics and particularly bedrock topography. As it is impossible to characterize the subsurface of an entire hydrological landscape using ERT, it is of key interest to identify the bedrock characteristics which dominate runoff generation to adapt and optimize the sampling design to the question of interest. For this study, we used 2D ERT images and auger measurements, collected on different sites in the Attert basin in Luxembourg, to characterize bedrock topography using geostatistics and shed light on those aspects which dominate runoff generation. Based on ERT images, we generated stochastic bedrock topographies and implemented them in a physically-based 2D hillslope model. With this approach, we were able to test the influence of different subsurface structures on the runoff generation. Our results highlight that ERT images can be useful for hydrological modelling. Especially the connection from the hillslope to the stream could be identified as important feature in the subsurface for the runoff generation whereas the microtopography of the bedrock seemed to be less relevant.

Watershed-Scale Fungal Community Characterization along a pH Gradient in a Subsurface Environment Cocontaminated with Uranium and Nitrate

PubMed Central

Jasrotia, Puja; Green, Stefan J.; Canion, Andy; Overholt, Will A.; Prakash, Om; Wafula, Denis; Hubbard, Daniela; Watson, David B.; Schadt, Christopher W.; Brooks, Scott C.

2014-01-01

The objective of this study was to characterize fungal communities in a subsurface environment cocontaminated with uranium and nitrate at the watershed scale and to determine the potential contribution of fungi to contaminant transformation (nitrate attenuation). The abundance, distribution, and diversity of fungi in subsurface groundwater samples were determined using quantitative and semiquantitative molecular techniques, including quantitative PCR of eukaryotic small-subunit rRNA genes and pyrosequencing of fungal internal transcribed spacer (ITS) regions. Potential bacterial and fungal denitrification was assessed in sediment-groundwater slurries amended with antimicrobial compounds and in fungal pure cultures isolated from the subsurface. Our results demonstrate that subsurface fungal communities are dominated by members of the phylum Ascomycota, and a pronounced shift in fungal community composition occurs across the groundwater pH gradient at the field site, with lower diversity observed under acidic (pH <4.5) conditions. Fungal isolates recovered from subsurface sediments, including cultures of the genus Coniochaeta, which were detected in abundance in pyrosequence libraries of site groundwater samples, were shown to reduce nitrate to nitrous oxide. Denitrifying fungal isolates recovered from the site were classified and found to be distributed broadly within the phylum Ascomycota and within a single genus of the Basidiomycota. Potential denitrification rate assays with sediment-groundwater slurries showed the potential for subsurface fungi to reduce nitrate to nitrous oxide under in situ acidic pH conditions. PMID:24389927

Washington Geothermal Play Fairway Analysis Data From Potential Field Studies

DOE Data Explorer

Anderson, Megan; Ritzinger, Brent; Glen, Jonathan; Schermerhorn, William

2017-12-20

A recent study which adapts play fairway analysis (PFA) methodology to assess geothermal potential was conducted at three locations (Mount Baker, Mount St. Helens seismic zone, and Wind River valley) along the Washington Cascade Range (Forson et al. 2017). Potential field (gravity and magnetic) methods which can detect subsurface contrasts in physical properties, provides a means for mapping and modeling subsurface geology and structure. As part of the WA-Cascade PFA project, we performed potential field studies by collecting high-resolution gravity and ground-magnetic data, and rock property measurements to (1) identify and constrain fault geometries (2) constrain subsurface lithologic distribution (3) study fault interactions (4) identify areas favorable to hydrothermal flow, and ultimately (5) guide future geothermal exploration at each location.

Large-scale fluid-deposited mineralization in Margaritifer Terra, Mars

NASA Astrophysics Data System (ADS)

Thomas, Rebecca J.; Potter-McIntyre, Sally L.; Hynek, Brian M.

2017-07-01

Mineral deposits precipitated from subsurface-sourced fluids are a key astrobiological detection target on Mars, due to the long-term viability of the subsurface as a habitat for life and the ability of precipitated minerals to preserve biosignatures. We report morphological and stratigraphic evidence for ridges along fractures in impact crater floors in Margaritifer Terra. Parallels with terrestrial analog environments and the regional context indicate that two observed ridge types are best explained by groundwater-emplaced cementation in the shallow subsurface and higher-temperature hydrothermal deposition at the surface, respectively. Both mechanisms have considerable astrobiological significance. Finally, we propose that morphologically similar ridges previously documented at the Mars 2020 landing site in NE Syrtis Major may have formed by similar mechanisms.

Evaluation of subsurface damage in concrete deck joints using impact echo method

DOE PAGES

Rickard, Larry; Choi, Wonchang

2016-01-01

Many factors can affect the overall performance and longevity of highway bridges, including the integrity of their deck joints. This study focuses on the evaluation of subsurface damage in deteriorated concrete deck joints, which includes the delamination and corrosion of the reinforcement. Impact echo and surface wave technology, mainly a portable seismic property analyzer (PSPA), were employed to evaluate the structural deficiency of concrete joints. Laboratory tests of core samples were conducted to verify the nondestructive test results. As a result, the primary advantage of the PSPA as a bridge assessment tool lies in its ability to assess the concrete’smore » modulus and to detect subsurface defects at a particular point simultaneously.« less

A shallow subsurface controlled release facility in Bozeman, Montana, USA, for testing near surface CO2 detection techniques and transport models

USGS Publications Warehouse

Spangler, L.H.; Dobeck, L.M.; Repasky, K.S.; Nehrir, A.R.; Humphries, S.D.; Keith, C.J.; Shaw, J.A.; Rouse, J.H.; Cunningham, A.B.; Benson, S.M.; Oldenburg, C.M.; Lewicki, J.L.; Wells, A.W.; Diehl, J.R.; Strazisar, B.R.; Fessenden, J.E.; Rahn, T.A.; Amonette, J.E.; Barr, J.L.; Pickles, W.L.; Jacobson, J.D.; Silver, E.A.; Male, E.J.; Rauch, H.W.; Gullickson, K.S.; Trautz, R.; Kharaka, Y.; Birkholzer, J.; Wielopolski, L.

2010-01-01

A controlled field pilot has been developed in Bozeman, Montana, USA, to study near surface CO2 transport and detection technologies. A slotted horizontal well divided into six zones was installed in the shallow subsurface. The scale and CO2 release rates were chosen to be relevant to developing monitoring strategies for geological carbon storage. The field site was characterized before injection, and CO2 transport and concentrations in saturated soil and the vadose zone were modeled. Controlled releases of CO2 from the horizontal well were performed in the summers of 2007 and 2008, and collaborators from six national labs, three universities, and the U.S. Geological Survey investigated movement of CO2 through the soil, water, plants, and air with a wide range of near surface detection techniques. An overview of these results will be presented. ?? 2009 The Author(s).

Potential for Remotely Sensed Soil Moisture Data in Hydrologic Modeling

NASA Technical Reports Server (NTRS)

Engman, Edwin T.

1997-01-01

Many hydrologic processes display a unique signature that is detectable with microwave remote sensing. These signatures are in the form of the spatial and temporal distributions of surface soil moisture and portray the spatial heterogeneity of hydrologic processes and properties that one encounters in drainage basins. The hydrologic processes that may be detected include ground water recharge and discharge zones, storm runoff contributing areas, regions of potential and less than potential ET, and information about the hydrologic properties of soils and heterogeneity of hydrologic parameters. Microwave remote sensing has the potential to detect these signatures within a basin in the form of volumetric soil moisture measurements in the top few cm. These signatures should provide information on how and where to apply soil physical parameters in distributed and lumped parameter models and how to subdivide drainage basins into hydrologically similar sub-basins.

Profilometry and subsurface imaging in point of care diagnosis in ocular disease and lymphedema after breast cancer treatment

NASA Astrophysics Data System (ADS)

Sayegh, Samir I.; Taghian, Alphonse

2013-03-01

Breast cancer-related lymphedema (BCRL) can be irreversible with profound negative impact on patients' quality of life. Programs that provide screening and active surveillance for BCRL are essential to determine whether early detection and intervention influences the course of lymphedema development. Established methods of quantitatively assessing lymphedema at early stages include "volume" methods such as perometry and bioimpedance spectroscopy. Here we demonstrate 1) Use of topographical techniques analogous to those used in corneal topography 2) Development of point-of-care lymphedema detection and characterization based on off-the-shelf hardward 3) The role of subsurface imaging 4) Multimodal diagnostics and integration yielding higher sensitivity/ specificity.

Hydrogeochemical exploration: a reconnaissance study on northeastern Seward Peninsula, Alaska: Chapter A in Studies by the U.S. Geological Survey in Alaska, vol. 15

USGS Publications Warehouse

Graham, Garth E.; Taylor, Ryan D.; Buckley, Steve

2015-01-01

A reconnaissance hydrogeochemical study employing high-resolution/high-sensitivity inductively coupled plasma mass spectrometry analysis of stream and seep water samples (n= 171) was conducted in an area of limited bedrock exposure on the northeastern Seward Peninsula, Alaska. Sampling was focused in drainages around four main areas—at the Anugi Pb-Zn-Ag occurrence and in streams upstream of historically and currently mined placer gold deposits in the Candle Creek, Utica, and Monument Mountain areas. The objective of the study was to determine whether distribution of elevated metal concentrations in water samples could “see” through sediment cover and provide evidence of bedrock sources for base metals and gold. Some observations include (1) elevated Ag, As, Pb, and Zn concentrations relative to the study area as a whole in stream and seep samples from over and downstream of part of the Anugi Pb-Zn-Ag prospect; (2) abrupt downstream increases in Tl and Sb ± Au concentrations coincident with the upstream termination of productive placer deposits in the Inmachuk and Old Glory Creek drainages near Utica; (3) high K, Mo, Sb, and F throughout much of the Inmachuk River drainage near Utica; and (4) elevated As ± base metals and Au at two sites along Patterson Creek near the town of Candle and three additional contiguous sites identified when an 85th percentile cut-off was employed. Molybdenum ± gold concentrations (>90th percentile) were also measured in samples from three sites on Glacier Creek near Monument Mountain. The hydrogeochemistry in some areas is consistent with limited stream-sediment data from the region, including high Pb-Zn-Ag-As concentrations associated with Anugi, as well as historical reports of arsenopyrite-bearing veins upstream of placer operations in Patterson Creek. Chemistry of samples in the Inmachuk River-Old Glory Creek area also suggest more laterally extensive stibnite- (and gold-?) bearing veining than is currently known in the Old Glory Creek drainage. Our results indicate that hydrogeochemistry can be a useful method of geochemical exploration and offer targets for follow-up rock, soil, and subsurface sampling to ascertain the presence of mineralized bedrock.

Evaluation of Urban Drainage Infrastructure: New York City Case Study

NASA Astrophysics Data System (ADS)

Hamidi, A.; Grossberg, M.; Khanbilvardi, R.

2017-12-01

Flood response in an urban area is the product of interactions of spatially and temporally varying rainfall and infrastructures. In urban areas, however, the complex sub-surface networks of tunnels, waste and storm water drainage systems are often inaccessible, pose challenges for modeling and prediction of the drainage infrastructure performance. The increased availability of open data in cities is an emerging information asset for a better understanding of the dynamics of urban water drainage infrastructure. This includes crowd sourced data and community reporting. A well-known source of this type of data is the non-emergency hotline "311" which is available in many US cities, and may contain information pertaining to the performance of physical facilities, condition of the environment, or residents' experience, comfort and well-being. In this study, seven years of New York City 311 (NYC311) call during 2010-2016 is employed, as an alternative approach for identifying the areas of the city most prone to sewer back up flooding. These zones are compared with the hydrologic analysis of runoff flooding zones to provide a predictive model for the City. The proposed methodology is an example of urban system phenomenology using crowd sourced, open data. A novel algorithm for calculating the spatial distribution of flooding complaints across NYC's five boroughs is presented in this study. In this approach, the features that represent reporting bias are separated from those that relate to actual infrastructure system performance. The sewer backup results are assessed with the spatial distribution of runoff in NYC during 2010-2016. With advances in radar technologies, a high spatial-temporal resolution data set for precipitation is available for most of the United States that can be implemented in hydrologic analysis of dense urban environments. High resolution gridded Stage IV radar rainfall data along with the high resolution spatially distributed land cover data are employed to investigate the urban pluvial flooding. The monthly results of excess runoff are compared with the sewer backup in NYC to build a predictive model of flood zones according to the 311 phone calls.

Characterization of stormwater discharges from Las Flores Industrial Park, Rio Grande, Puerto Rico, 1998-99

USGS Publications Warehouse

Rodriguez, Jose M.

2000-01-01

Stormwater discharges from Las Flores Industrial Park, Rio Grande, Puerto Rico, were characterized from June 1998 to July 1999 by measuring the flow rate at two outfalls, delineating the drainage areas for each outfall, and calculating the volume of the stormwater discharges. Stormwater-discharge samples were collected and analyzed to determine the quality of the discharges. Constituent loads and loads per area were estimated for each drainage area. The studied drainage subareas covered approximately 46 percent of the total area of the Las Flores Industrial Park. Industrial groups represented in the study areas include manufacturers of textile, electronics, paper, fabricated metal, plastic, and chemical products. The concentrations of oil and grease (1 to 6 milligrams per liter), biochemical oxygen demand (4.7 to 16 milligrams per liter), total organic carbon (5.8 to 36 milligrams per liter), total suspended solids (28 to 100 milligrams per liter), and total phosphorous (0.11 to 0.78 milligrams per liter) from all the samples collected were less than the U.S. Environmental Protection Agency stormwater benchmark concentrations. Concentrations of chemical oxygen demand (15.8 to 157 milligrams per liter) and nitrate and nitrite (0.06 to 1.75 milligrams per liter) exceeded benchmark concentrations at one of the studied drainage areas. Total Kjeldahl nitrogen concentrations (1.00 to 3.20 milligrams per liter) exceeded the benchmark concentrations at the two studied drainage areas. Maximum concentrations for oil and grease, biochemical oxygen demand, chemical oxygen demand, total organic carbon, total Kjeldahl nitrogen, nitrate plus nitrite, and total phosphorous were detected in an area where electronics, plastics, and chemical products are currently manufactured. The maximum concentration of total suspended solids was detected at an area where textile, paper, plastic, chemical, and fabricated metal products are manufactured.