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

Science.gov (United States)

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.

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

Science.gov (United States)

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

Subsurface drainage

CSIR Research Space (South Africa)

Van Der

1993-09-01

Full Text Available and long term behavior were evaluated. Laboratory tests for geotextile selection are recommended and tentative criteria given. The use of fin drains was evaluated in the laboratory and a field study to monitor the efficacy of drainage systems was started...

The Effect of Different Subsurface Drainage Systems on Improvement of Water Flow in Paddy fields

Directory of Open Access Journals (Sweden)

ghassem aghajani mazandarani

2017-03-01

Full Text Available Introduction: Better use of water and soil resources in paddy fields, increase in rice production and farmer's income, installation of subsurface drainage system is necessary. The main goalof these systems, are aeration conditions improvement prevention of water logging, yield increase, land use increase and multiuse of the land. In different countries, installation of subsurface drainage cause yield increase and working condition on the land, but no research has been conducted in different depths and spacing. On the other hand, spacing and depth are the most important parameters in the installation of drainage systems, have a direct effect on incoming water into the drains. The aim of this research, is an investigation of the effect of subsurface drainage with different depths and spacing on discharge rate variation and water table fall, in order to analyze the improvement of water flow movement in the soil. Also, study the effect of different drainage systems on the increase of the canola yield as the second cultivation in these treatments have been compared. Materials and Methods: To measure hydraulic conductivity in different depths, the auger holes have been dug (excavated. The saturated hydraulic conductivity in these holes wasdetermined using Ernst method (1950 before installation of drainage systems. In the drainage pilot plot of Sari Agricultural Sciences and Natural Resources University three subsurface drainage systems with mineral envelope have been installed. 1- The first one with the 0.9 m depth and 30 m spacing (D90 L30, 2- The second one with 0.65 m depth and 15 m spacing (D0.65 L15 and 3- The third one with 0.65 m depth and spacing (D0.65 L30 and one bi-level system with mineral envelope including four drains of 15 m spacing with 0.9 m and 0.65 m depths were installed alternatively. After auger hole equipment installations, in the middle spacing of two subsurface and water table reading possible, the water table fluctuation and

Social impact assessment of subsurface drainage

International Nuclear Information System (INIS)

Azhar, A.H.; Rafiq, M.; Alam, M.M.

2005-01-01

Social impact assessment of four drainage projects namely; Mardan SCARP Project (MSP), Fourth Drainage Project, Faisalabad (FDP), Chashma Command Area Development Project (CCADP) and Mirpurkhas Tile Drainage Project (MKOP) has been done. For this purpose, a socio-technical survey was carried out in which randomly selected farmers were interviewed. The investigations revealed that although significant population (-77%) at four study sites was educated, yet, the farmers were not satisfactorily educated to understand the operation and maintenance of drainage systems. The perusal of data revealed that 14%, 17% and 25% respondents from MSP, FOP and MKDP respectively had to migrate from their villages mainly due to pre-project water logging problem. However, installation of drainage systems in those areas improved the situation resulting in the increase of farm income, which was an attraction for them to return to their villages. The analysis of farm mechanization revealed that at MSP, FDP, CCADP and MKOP sites 71%, 42%, 40% and 75% respondents respectively were tractor owners and owners of some kind of other farm implements, whereas, remaining respondents were performing their farm operations on hire basis. Although, hire operation basis is much better than traditional ways, however, improving the farm mechanization could further enhance the benefits of drainage systems. The investigations revealed that a significant majority of respondents at four project sites had never met the Agricultural Extension Officer. The farmers' access to financing institutions such as ZTB was also negligible. There was lack of coordination among various departments such as WAPDA, Agriculture Extension and Irrigation and Power Department at four study sites. Nevertheless, the overall social impact investigations did reveal that the objectives of drainage systems installation have been achieved in terms of uplifting the socio-economic conditions of drainage areas. To make the efficient use of

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

Science.gov (United States)

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

Implications of deep drainage through saline clay for groundwater recharge and sustainable cropping in a semi-arid catchment, Australia

Science.gov (United States)

Timms, W. A.; Young, R. R.; Huth, N.

2012-04-01

The magnitude and timing of deep drainage and salt leaching through clay soils is a critical issue for dryland agriculture in semi-arid regions (2000 mm yr-1) such as parts of Australia's Murray-Darling Basin (MDB). In this rare study, hydrogeological measurements and estimations of the historic water balance of crops grown on overlying Grey Vertosols were combined to estimate the contribution of deep drainage below crop roots to recharge and salinization of shallow groundwater. Soil sampling at two sites on the alluvial flood plain of the Lower Namoi catchment revealed significant peaks in chloride concentrations at 0.8-1.2 m depth under perennial vegetation and at 2.0-2.5 m depth under continuous cropping indicating deep drainage and salt leaching since conversion to cropping. Total salt loads of 91-229 t ha-1 NaCl equivalent were measured for perennial vegetation and cropping, with salinity to ≥ 10 m depth that was not detected by shallow soil surveys. Groundwater salinity varied spatially from 910 to 2430 mS m-1 at 21 to 37 m depth (N = 5), whereas deeper groundwater was less saline (290 mS m-1) with use restricted to livestock and rural domestic supplies in this area. The Agricultural Production Systems Simulator (APSIM) software package predicted deep drainage of 3.3-9.5 mm yr-1 (0.7-2.1% rainfall) based on site records of grain yields, rainfall, salt leaching and soil properties. Predicted deep drainage was highly episodic, dependent on rainfall and antecedent soil water content, and over a 39 yr period was restricted mainly to the record wet winter of 1998. During the study period, groundwater levels were unresponsive to major rainfall events (70 and 190 mm total), and most piezometers at about 18 m depth remained dry. In this area, at this time, recharge appears to be negligible due to low rainfall and large potential evapotranspiration, transient hydrological conditions after changes in land use and a thick clay dominated vadose zone. This is in

Tubo de PVC liso com diferentes envoltórios como material alternativo na drenagem subterrânea Smooth PVC tube with different envelopes as an alternative material in the subsurface drainage

Directory of Open Access Journals (Sweden)

Florício P. de Almeida

2003-04-01

Full Text Available Em regiões áridas e semi-áridas irrigadas a drenagem é, freqüentemente, necessária para prevenir o encharcamento do solo e o controle da salinidade. Um dos principais obstáculos na instalação de um sistema de drenagem subterrânea é o alto custo do investimento inicial. Assim, alguma contribuição que reduza o custo da instalação dos drenos e também do material usado, é altamente vantajosa. Diante disso, o objetivo desta pesquisa foi avaliar, em condições de laboratório, o desempenho hidráulico do sistema drenante constituído pelo tubo de PVC liso, próprio para esgoto doméstico, de 50,0 mm de diâmetro nominal e área aberta de 23,0 cm² m-1, e por três tipos de envoltório. O desempenho do tubo drenante de PVC liso demonstrou que esse material é tecnicamente viável para drenagem agrícola, principalmente com o uso de brita como envoltório.In irrigated arid and semi-arid regions the drainage is, frequently, necessary to prevent the waterlogging of the soil and to control the salinity. One of the main obstacles in the installation of a subsurface drainage system is the high cost of the initial investment. Thus, some contribution that reduces the cost of the installation of the drains and also of the material used is highly advantageous. The objective of this research was to evaluate, under laboratory conditions, the hydraulic performance of the drainage system constituted by smooth PVC tube used for sewer with 50.0 mm of nominal diameter and open area of 23.0 cm² m-1 and different types of envelopes, as an alternative material for subsurface drainage. The performance of the smooth PVC tube demonstrated that this material is technically viable for agricultural drainage principally when used with single stones as envelope.

Implications of deep drainage through saline clay for groundwater recharge and sustainable cropping in a semi-arid catchment, Australia

Directory of Open Access Journals (Sweden)

W. A. Timms

2012-04-01

Full Text Available The magnitude and timing of deep drainage and salt leaching through clay soils is a critical issue for dryland agriculture in semi-arid regions (<500 mm yr⁻¹ rainfall, potential evapotranspiration >2000 mm yr⁻¹ such as parts of Australia's Murray-Darling Basin (MDB. In this rare study, hydrogeological measurements and estimations of the historic water balance of crops grown on overlying Grey Vertosols were combined to estimate the contribution of deep drainage below crop roots to recharge and salinization of shallow groundwater. Soil sampling at two sites on the alluvial flood plain of the Lower Namoi catchment revealed significant peaks in chloride concentrations at 0.8–1.2 m depth under perennial vegetation and at 2.0–2.5 m depth under continuous cropping indicating deep drainage and salt leaching since conversion to cropping. Total salt loads of 91–229 t ha⁻¹ NaCl equivalent were measured for perennial vegetation and cropping, with salinity to ≥ 10 m depth that was not detected by shallow soil surveys. Groundwater salinity varied spatially from 910 to 2430 mS m⁻¹ at 21 to 37 m depth (N = 5, whereas deeper groundwater was less saline (290 mS m⁻¹ with use restricted to livestock and rural domestic supplies in this area. The Agricultural Production Systems Simulator (APSIM software package predicted deep drainage of 3.3–9.5 mm yr⁻¹ (0.7–2.1% rainfall based on site records of grain yields, rainfall, salt leaching and soil properties. Predicted deep drainage was highly episodic, dependent on rainfall and antecedent soil water content, and over a 39 yr period was restricted mainly to the record wet winter of 1998. During the study period, groundwater levels were unresponsive to major rainfall events (70 and 190 mm total, and most piezometers at about 18 m depth remained dry. In this area, at this time, recharge appears to be negligible due to low

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

Science.gov (United States)

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 ...

Salinity maxima associated with some sub-surface water masses in the upper layers of the Bay of Bengal

Digital Repository Service at National Institute of Oceanography (India)

Varadachari, V.V.R.; Murty, C.S.; Reddy, C.V.G.

The distribution of some sub-surface water masses in the western bay of Bengal during the south-west monsoon period is presented. Based on the salinity maxima and sigma t values the existence of waters of Persian Gulf and Red Sea origin could...

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

Science.gov (United States)

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...

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

Science.gov (United States)

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.

Integrated approach for demarcating subsurface pollution and saline water intrusion zones in SIPCOT area: a case study from Cuddalore in Southern India.

Science.gov (United States)

Sankaran, S; Sonkamble, S; Krishnakumar, K; Mondal, N C

2012-08-01

This paper deals with a systematic hydrogeological, geophysical, and hydrochemical investigations carried out in SIPCOT area in Southern India to demarcate groundwater pollution and saline intrusion through Uppanar River, which flows parallel to sea coast with high salinity (average TDS 28, 870 mg/l) due to back waters as well as discharge of industrial and domestic effluents. Hydrogeological and geophysical investigations comprising topographic survey, self-potential, multi-electrode resistivity imaging, and water quality monitoring were found the extent of saline water intrusion in the south and pockets of subsurface pollution in the north of the study area. Since the area is beset with highly permeable unconfined quaternary alluvium forming potential aquifer at shallow depth, long-term excessive pumping and influence of the River have led to lowering of the water table and degradation of water quality through increased salinity there by generating reversal of hydraulic gradient in the south. The improper management of industrial wastes and left over chemicals by closed industries has led surface and subsurface pollution in the north of the study area.

Water Table Recession in Subsurface Drained Soils

OpenAIRE

Moustafa, Mahmoud Mohamed; Yomota, Atsushi

1999-01-01

Theoretical drainage equations are intensively tested in many parts of humid and arid regions and are commonly used in drainage design. However, this is still a great concern in Japan as the drainage design is exclusively based on local experiences and empirical basis. There is a need therefore to evaluate the theoretical drainage equations under Japanese field conditions to recommend equations for design of subsurface drainage systems. This was the main motivation for this study. While drain...

Low salinity hydrocarbon water disposal through deep subsurface drip irrigation: leaching of native selenium

Science.gov (United States)

Bern, Carleton R.; Engle, Mark A.; Boehlke, Adam R.; Zupancic, John W.; Brown, Adrian; Figueroa, Linda; Wolkersdorfer, Christian

2013-01-01

A subsurface drip irrigation system is being used in Wyoming’s Powder River Basin that treats high sodium, low salinity, coal bed methane (CBM) produced water with sulfuric acid and injects it into cropped fields at a depth of 0.92 m. Dissolution of native gypsum releases calcium that combats soil degradation that would otherwise result from high sodium water. Native selenium is leached from soil by application of the CBM water and traces native salt mobilization to groundwater. Resulting selenium concentrations in groundwater at this alluvial site were generally low (0.5–23 μg/L) compared to Wyoming’s agricultural use suitability standard (20 μg/L).

PASSIVE TREATMENT OF ACID ROCK DRAINAGE FROM A SUBSURFACE MINE

Science.gov (United States)

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...

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

Science.gov (United States)

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.

Analyzing subsurface drain network performance in an agricultural monitoring site with a three-dimensional hydrological model

Science.gov (United States)

Nousiainen, Riikka; Warsta, Lassi; Turunen, Mika; Huitu, Hanna; Koivusalo, Harri; Pesonen, Liisa

2015-10-01

Effectiveness of a subsurface drainage system decreases with time, leading to a need to restore the drainage efficiency by installing new drain pipes in problem areas. The drainage performance of the resulting system varies spatially and complicates runoff and nutrient load generation within the fields. We presented a method to estimate the drainage performance of a heterogeneous subsurface drainage system by simulating the area with the three-dimensional hydrological FLUSH model. A GIS analysis was used to delineate the surface runoff contributing area in the field. We applied the method to reproduce the water balance and to investigate the effectiveness of a subsurface drainage network of a clayey field located in southern Finland. The subsurface drainage system was originally installed in the area in 1971 and the drainage efficiency was improved in 1995 and 2005 by installing new drains. FLUSH was calibrated against total runoff and drain discharge data from 2010 to 2011 and validated against total runoff in 2012. The model supported quantification of runoff fractions via the three installed drainage networks. Model realisations were produced to investigate the extent of the runoff contributing areas and the effect of the drainage parameters on subsurface drain discharge. The analysis showed that better model performance was achieved when the efficiency of the oldest drainage network (installed in 1971) was decreased. Our analysis method can reveal the drainage system performance but not the reason for the deterioration of the drainage performance. Tillage layer runoff from the field was originally computed by subtracting drain discharge from the total runoff. The drains installed in 1995 bypass the measurement system, which renders the tillage layer runoff calculation procedure invalid after 1995. Therefore, this article suggests use of a local correction coefficient based on the simulations for further research utilizing data from the study area.

Socially optimal drainage system and agricultural biodiversity: a case study for Finnish landscape.

Science.gov (United States)

Saikkonen, Liisa; Herzon, Irina; Ollikainen, Markku; Lankoski, Jussi

2014-12-15

This paper examines the socially optimal drainage choice (surface/subsurface) for agricultural crop cultivation in a landscape with different land qualities (fertilities) when private profits and nutrient runoff damages are taken into account. We also study the measurable social costs to increase biodiversity by surface drainage when the locations of the surface-drained areas in a landscape affect the provided biodiversity. We develop a general theoretical model and apply it to empirical data from Finnish agriculture. We find that for low land qualities the measurable social returns are higher to surface drainage than to subsurface drainage, and that the profitability of subsurface drainage increases along with land quality. The measurable social costs to increase biodiversity by surface drainage under low land qualities are negative. For higher land qualities, these costs depend on the land quality and on the biodiversity impacts. Biodiversity conservation plans for agricultural landscapes should focus on supporting surface drainage systems in areas where the measurable social costs to increase biodiversity are negative or lowest. Copyright © 2014 Elsevier Ltd. All rights reserved.

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

Science.gov (United States)

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.

Assessment of waterlogging in agricultural megaprojects in the closed drainage basins of the Western Desert of Egypt

Directory of Open Access Journals (Sweden)

M. El Bastawesy

2013-04-01

Full Text Available This paper investigates the development of waterlogging in the cultivated and arable areas within typical dryland closed drainage basins (e.g. the Farafra and Baharia Oases, which are located in the Western Desert of Egypt. Multi-temporal remote sensing data of the Landsat Thematic Mapper (TM and Enhanced Thematic Mapper (ETM+ were collected and processed to detect the land cover changes; cultivations, and the extent of water ponds and seepage channels. The Shuttle Radar Topography Mission (SRTM digital elevation model (DEM has been processed to delineate the catchment morphometrical parameters (i.e. drainage networks, catchment divides and surface areas of different basins and to examine the spatial distribution of cultivated fields and their relation to the extracted drainage networks. The soil of these closed drainage basins is mainly shallow and lithic with high calcium carbonate content; therefore, the downward percolation of excess irrigation water is limited by the development of subsurface hardpan, which also saturates the upper layer of soil with water. The subsurface seepage from the newly cultivated areas in the Farafra Oasis has revealed the pattern of buried alluvial channels, which are waterlogged and outlined by the growth of diagnostic saline shrubs. Furthermore, the courses of these waterlogged channels are coinciding with their counterparts of the SRTM DEM, and the recent satellite images show that the surface playas in the downstream of these channels are partially occupied by water ponds. On the other hand, a large water pond has occupied the main playa and submerged the surrounding fields, as a large area has been cultivated within a relatively small closed drainage basin in the Baharia Oasis. The geomorphology of closed drainage basins has to be considered when planning for a new cultivation in dryland catchments to better control waterlogging hazards. The "dry-drainage" concept can be implemented as the drainage and

Reuse of drainage water in the Nile Delta; monitoring, modelling and analysis; final report Reuse of Drainage Water Project

NARCIS (Netherlands)

Staring Centrum, Instituut voor Onderzoek van het LandelijkGebied

1995-01-01

The effects of reusing drainage water have been evaluated and other options to increase the water utilization rate in Egypt explored. The results are an operational network for monitoring drainage water discharges and salinity along the major drains, a database for monitored drainage water

Anthropogenic modifications to drainage conditions on streamflow variability in the Wabash River basin, Indiana

Science.gov (United States)

Chiu, C.; Bowling, L. C.

2011-12-01

The Wabash River watershed is the largest watershed in Indiana and includes the longest undammed river reach east of the Mississippi River. The land use of the Wabash River basin began to significantly change from mixed woodland dominated by small lakes and wetlands to agriculture in the mid-1800s and agriculture is now the predominant land use. Over 80% of natural wetland areas were drained to facilitate better crop production through both surface and subsurface drainage applications. Quantifying the change in hydrologic response in this intensively managed landscape requires a hydrologic model that can represent wetlands, crop growth, and impervious area as well as subsurface and surface drainage enhancements, coupled with high resolution soil and topographic inputs. The Variable Infiltration Capacity (VIC) model wetland algorithm has been previously modified to incorporate spatially-varying estimates of water table distribution using a topographic index approach, as well as a simple urban representation. Now, the soil water characteristics curve and a derived drained to equilibrium moisture profile are used to improve the model's estimation of the water table. In order to represent subsurface (tile) drainage, the tile drainage component of subsurface flow is calculated when the simulated water table rises above a specified drain depth. A map of the current estimated extent of subsurface tile drainage for the Wabash River based on a decision tree classifier of soil drainage class, soil slope and agricultural land use is used to activate the new tile drainage feature in the VIC model, while wetland depressional storage capacity is extracted from digital elevation and soil information. This modified VIC model is used to evaluate the performance of model physical variations in the intensively managed hydrologic regime of the Wabash River system and to understand the role of surface and subsurface storage, and land use and land cover change on hydrologic change.

Agricultural drainage water quality

International Nuclear Information System (INIS)

Madani, A.; Gordon, R.

2002-01-01

'Full text:' Agricultural drainage systems have been identified as potential contributors of non-point source pollution. Two of the major concerns have been with nitrate-nitrogen (NO3 - -N) concentrations and bacteria levels exceeding the Maximum Acceptable Concentration in drainage water. Heightened public awareness of environmental issues has led to greater pressure to maintain the environmental quality of water systems. In an ongoing field study, three experiment sites, each with own soil properties and characteristics, are divided into drainage plots and being monitored for NO3 - -N and fecal coliforms contamination. The first site is being used to determine the impact of the rate of manure application on subsurface drainage water quality. The second site is being used to determine the difference between hog manure and inorganic fertilizer in relation to fecal coliforms and NO3-N leaching losses under a carrot rotation system. The third site examines the effect of timing of manure application on water quality, and is the only site equipped with a surface drainage system, as well as a subsurface drainage system. Each of the drains from these fields lead to heated outflow buildings to allow for year-round measurements of flow rates and water samples. Tipping buckets wired to data-loggers record the outflow from each outlet pipe on an hourly basis. Water samples, collected from the flowing drains, are analyzed for NO3 - -N concentrations using the colorimetric method, and fecal coliforms using the Most Probable Number (MPN) method. Based on this information, we will be able better positioned to assess agricultural impacts on water resources which will help towards the development on industry accepted farming practices. (author)

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

Science.gov (United States)

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.

Long-Term Hydrologic Impacts of Controlled Drainage Using DRAINMOD

Science.gov (United States)

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.

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

Science.gov (United States)

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.

Rye cover crop and gamagrass strip effects on NO3 concentration and load in tile drainage.

Science.gov (United States)

Kaspar, T C; Jaynes, D B; Parkin, T B; Moorman, T B

2007-01-01

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 concentrations in subsurface drainage to acceptable levels; therefore, additional approaches need to be devised. We compared two cropping system modifications for NO3 concentration and load in subsurface drainage water for a no-till corn (Zea mays L.)-soybean (Glycine max [L.] Merr.) management system. In one treatment, eastern gamagrass (Tripsacum dactyloides L.) was grown in permanent 3.05-m-wide strips above the tiles. For the second treatment, a rye (Secale cereale L.) winter cover crop was seeded over the entire plot area each year near harvest and chemically killed before planting the following spring. Twelve 30.5x42.7-m subsurface-drained field plots were established in 1999 with an automated system for measuring tile flow and collecting flow-weighted samples. Both treatments and a control were initiated in 2000 and replicated four times. Full establishment of both treatments did not occur until fall 2001 because of dry conditions. Treatment comparisons were conducted from 2002 through 2005. The rye cover crop treatment significantly reduced subsurface drainage water flow-weighted NO3 concentrations and NO3 loads in all 4 yr. The rye cover crop treatment did not significantly reduce cumulative annual drainage. Averaged over 4 yr, the rye cover crop reduced flow-weighted NO3 concentrations by 59% and loads by 61%. The gamagrass strips did not significantly reduce cumulative drainage, the average annual flow-weighted NO3 concentrations, or cumulative NO3 loads averaged over the 4 yr. Rye winter cover crops grown after corn and soybean have the potential to reduce the NO3 concentrations and loads delivered to surface waters by subsurface drainage systems.

Parameterizing sub-surface drainage with geology to improve modeling streamflow responses to climate in data limited environments

Directory of Open Access Journals (Sweden)

C. L. Tague

2013-01-01

Full Text Available Hydrologic models are one of the core tools used to project how water resources may change under a warming climate. These models are typically applied over a range of scales, from headwater streams to higher order rivers, and for a variety of purposes, such as evaluating changes to aquatic habitat or reservoir operation. Most hydrologic models require streamflow data to calibrate subsurface drainage parameters. In many cases, long-term gage records may not be available for calibration, particularly when assessments are focused on low-order stream reaches. Consequently, hydrologic modeling of climate change impacts is often performed in the absence of sufficient data to fully parameterize these hydrologic models. In this paper, we assess a geologic-based strategy for assigning drainage parameters. We examine the performance of this modeling strategy for the McKenzie River watershed in the US Oregon Cascades, a region where previous work has demonstrated sharp contrasts in hydrology based primarily on geological differences between the High and Western Cascades. Based on calibration and verification using existing streamflow data, we demonstrate that: (1 a set of streams ranging from 1st to 3rd order within the Western Cascade geologic region can share the same drainage parameter set, while (2 streams from the High Cascade geologic region require a different parameter set. Further, we show that a watershed comprised of a mixture of High and Western Cascade geologies can be modeled without additional calibration by transferring parameters from these distinctive High and Western Cascade end-member parameter sets. More generally, we show that by defining a set of end-member parameters that reflect different geologic classes, we can more efficiently apply a hydrologic model over a geologically complex landscape and resolve geo-climatic differences in how different watersheds are likely to respond to simple warming scenarios.

Site Recommendation Subsurface Layout

International Nuclear Information System (INIS)

C.L. Linden

2000-01-01

The purpose of this analysis is to develop a Subsurface Facility layout that is capable of accommodating the statutory capacity of 70,000 metric tons of uranium (MTU), as well as an option to expand the inventory capacity, if authorized, to 97,000 MTU. The layout configuration also requires a degree of flexibility to accommodate potential changes in site conditions or program requirements. The objective of this analysis is to provide a conceptual design of the Subsurface Facility sufficient to support the development of the Subsurface Facility System Description Document (CRWMS M andO 2000e) and the ''Emplacement Drift System Description Document'' (CRWMS M andO 2000i). As well, this analysis provides input to the Site Recommendation Consideration Report. The scope of this analysis includes: (1) Evaluation of the existing facilities and their integration into the Subsurface Facility design. (2) Identification and incorporation of factors influencing Subsurface Facility design, such as geological constraints, thermal loading, constructibility, subsurface ventilation, drainage control, radiological considerations, and the Test and Evaluation Facilities. (3) Development of a layout showing an available area in the primary area sufficient to support both the waste inventories and individual layouts showing the emplacement area required for 70,000 MTU and, if authorized, 97,000 MTU

Desiccation-crack-induced salinization in deep clay sediment

Directory of Open Access Journals (Sweden)

S. Baram

2013-04-01

Full Text Available A study on water infiltration and solute transport in a clayey vadose zone underlying a dairy farm waste source was conducted to assess the impact of desiccation cracks on subsurface evaporation and salinization. The study is based on five years of continuous measurements of the temporal variation in the vadose zone water content and on the chemical and isotopic composition of the sediment and pore water in it. The isotopic composition of water stable isotopes (δ18O and δ2H in water and sediment samples, from the area where desiccation crack networks prevail, indicated subsurface evaporation down to ~ 3.5 m below land surface, and vertical and lateral preferential transport of water, following erratic preferential infiltration events. Chloride (Cl− concentrations in the vadose zone pore water substantially increased with depth, evidence of deep subsurface evaporation and down flushing of concentrated solutions from the evaporation zones during preferential infiltration events. These observations led to development of a desiccation-crack-induced salinization (DCIS conceptual model. DCIS suggests that thermally driven convective air flow in the desiccation cracks induces evaporation and salinization in relatively deep sections of the subsurface. This conceptual model supports previous conceptual models on vadose zone and groundwater salinization in fractured rock in arid environments and extends its validity to clayey soils in semi-arid environments.

Water logging and salinity control for environmentally sustainable crop production

International Nuclear Information System (INIS)

Chaudhry, M.R.; Bhutta, M.N.

2005-01-01

Irrigation supplies at proper time and adequate quantities are imperative for potential agricultural production under arid and semi-arid climatic conditions. To achieve this goal one of the largest integrated irrigation network was established. Without adequate drainage it resulted in the problems of water logging and salinity. To control these problems a big programme of Salinity Control and Reclamation projects (SCARPs) was initiated during 1960 and 82 such SCARPs have been completed and 9 were in progress up to June, 2002 covering an area of 18.6 ma (7.5 mh) at a cost of Rs.93 billions. Under these projects 12746 tube wells in fresh, 3572 in saline groundwater and 13726 km surface and 12612 km tile pipes covering 6391.7 ha, 160 km interceptor drains have been constructed an area of 0.998 ma (GCA). In addition to this some other measures like on farm water management, canal command project, canal lining, construction of evaporation ponds, establishment of research Inst./Organizations were also taken. Many drainage plans like Master Plan (1963), Northern Regional Plan (1967), Water Sector Investment Plan Study (1990), Right Bank Master Plan (1992), Drainage Sector Environmental Assessment (1993) and National Drainage Programme (1995) were prepared and implemented. The cost of the, phase-I of the National Drainage Programme was 785 million US$. The main activities undertaken were remodeling/extension of existing surface and new drains; rehabilitation/replacement of saline ground water (SGW) tube wells; construction of interceptor drains, reclamation of waterlogged areas through biological drainage and transfer of fresh ground water tube wells to the farmers. The data indicate that all the measures taken have played a significant role in reducing the water logging, salinity/sodicity and have increased the crop production and consequently improved the socio-economic conditions of the peoples especially the farming community. The environment in these areas was also

Biofuel as an Integrated Farm Drainage Management crop: A bioeconomic analysis

Science.gov (United States)

Levers, L. R.; Schwabe, K. A.

2017-04-01

Irrigated agricultural lands in arid regions often suffer from soil salinization and lack of drainage, which affect environmental quality and productivity. Integrated Farm Drainage Management (IFDM) systems, where drainage water generated from higher-valued crops grown on high quality soils are used to irrigate salt-tolerant crops grown on marginal soils, is one possible strategy for managing salinity and drainage problems. If the IFDM crop were a biofuel crop, both environmental and private benefits may be generated; however, little is known about this possibility. As such, we develop a bioeconomic programming model of irrigated agricultural production to examine the role salt-tolerant biofuel crops might play within an IFDM system. Our results, generated by optimizing profits over land, water, and crop choice decisions subject to resource constraints, suggest that based on the private profits alone, biofuel crops can be a competitive alternative to the common practices of land retirement and nonbiofuel crop production under both low to high drainage water salinity. Yet IFDM biofuel crop production generates 30-35% fewer GHG emissions than the other strategies. The private market competitiveness coupled with the public good benefits may justify policy changes encouraging the growth of IFDM biofuel crops in arid agricultural areas globally.

Drainage filters and constructed wetlands to mitigate site-specific nutrient losses

DEFF Research Database (Denmark)

Kjærgaard, Charlotte; Hoffmann, Carl Christian; Iversen, Bo Vangsø

Despite substantial efforts, the leaching of nutrients from agricultural land is still a serious and costly environmental problem in Denmark and elsewhere. The quality goals of the European Water Framework Directive (WFD) for the aquatic environment require a substantial reduction of diffuse nutr...... drainage. The project studies different approaches of implementing the filter technologies including drainage well or drainage pipe filters as well as surface-flow and sub-surface flow constructed wetlands....

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

Science.gov (United States)

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

Drainage filters and constructed wetlands to mitigate sitespecific nutrient losses

DEFF Research Database (Denmark)

Kjærgaard, Charlotte; Canga, Eriona; Heckrath, Goswin Johann

2012-01-01

Research Council, aims at providing the scientific basis for developing cost-effective filter technologies targeting P-retention and N-removal in agricultural subsurface drainage. The project studies different approaches of implementing the filter technologies including drainage well filters as well...... typically applied to point sources. This calls for a shift of paradigm towards the development of new, cost-efficient technologies to mitigate site-specific nutrient losses in drainage. A newly launched Danish research project “SUPREME-TECH” (2010-2015) (www.supreme-tech.dk) funded by the Danish Strategic...... in drainage water to below environmental threshold values (

A Theoretical Study of Subsurface Drainage Model Simulation of ...

African Journals Online (AJOL)

User

Simulation of Drainage Flow and Leaching in Salt Affected ... mg/l with an impermeable layer at 10 m depth and impermeable field boundaries. .... The hydraulic where D is the free molecular diffusion ...... Dynamics of fluid in porous media.

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

Science.gov (United States)

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.

WATER RETENTION OPTION OF DRAINAGE SYSTEM FOR DRY SEASON CORN CULTIVATION AT TIDAL LOWLAND AREA

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Bakri

2015-10-01

Full Text Available Farming constraint at tidal lowland area is about water management related to the nature of excessive water during wet season and insufficient water during dry season. This field research objectives was to find out the corn crop cultivation in August 2014 which entered dry season. The installation of subsurface drainage that previously had functioned as water discharge was converted into water retention. The research results showed that corn had grown well during peak dry season period (October in which water table was at –50 cm below soil surface, whereas water table depth was dropped to –70 cm below soil surface in land without subsurface drainage. This condition implied that installation of subsurface drainage at dry season had function as water retention, not as water discharge. Therefore, network function was inverted from water discharge into water retention. It had impact on the development of optimum water surface that flow in capillary mode to fulfill the crop’s water requirement. Corn production obtained was 6.4 t ha-1. This condition was very promising though still below the maximum national production. The applications of subsurface drainage was still not optimum due to the supply of water from the main system was not the same because of the soil physical properties diversity and topography differences.

Salinity anomaly as a trigger for ENSO events.

Science.gov (United States)

Zhu, Jieshun; Huang, Bohua; Zhang, Rong-Hua; Hu, Zeng-Zhen; Kumar, Arun; Balmaseda, Magdalena A; Marx, Lawrence; Kinter, James L

2014-10-29

According to the classical theories of ENSO, subsurface anomalies in ocean thermal structure are precursors for ENSO events and their initial specification is essential for skillful ENSO forecast. Although ocean salinity in the tropical Pacific (particularly in the western Pacific warm pool) can vary in response to El Niño events, its effect on ENSO evolution and forecasts of ENSO has been less explored. Here we present evidence that, in addition to the passive response, salinity variability may also play an active role in ENSO evolution, and thus important in forecasting El Niño events. By comparing two forecast experiments in which the interannually variability of salinity in the ocean initial states is either included or excluded, the salinity variability is shown to be essential to correctly forecast the 2007/08 La Niña starting from April 2007. With realistic salinity initial states, the tendency to decay of the subsurface cold condition during the spring and early summer 2007 was interrupted by positive salinity anomalies in the upper central Pacific, which working together with the Bjerknes positive feedback, contributed to the development of the La Niña event. Our study suggests that ENSO forecasts will benefit from more accurate salinity observations with large-scale spatial coverage.

Hydro-geochemistry and retention of phosphorus in drainage filters and constructed wetlands

DEFF Research Database (Denmark)

Canga, Eriona; Kjærgaard, Charlotte; Iversen, Bo Vangsø

Research Council, aims at providing the scientific basis for developing cost-effective filter technologies targeting P-retention and N-removal in agricultural subsurface drainage. The project studies different approaches of implementing the filter technologies including drainage well filters as well...... typically applied to point sources. This calls for a shift of paradigm towards the development of new, cost-efficient technologies to mitigate site-specific nutrient losses in drainage. A newly launched Danish research project “SUPREME-TECH” (2010-2015) (www.supreme-tech.dk) funded by the Danish Strategic...... in drainage water to below environmental threshold values (

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

Science.gov (United States)

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...

Combined electromagnetic geophysical mapping at Arctic perennial saline springs: Possible applications for the detection of water in the shallow subsurface of Mars

Science.gov (United States)

Samson, C.; Mah, J.; Haltigin, T.; Holladay, S.; Ralchenko, M.; Pollard, W.; Monteiro Santos, F. A.

2017-05-01

Perennial springs at the Gypsum Hill site on Axel Heiberg Island in the Canadian Arctic (79°24‧N, 90°44‧W) represent a high-fidelity analogue to hydrothermal systems that might exist on Mars. The springs were surveyed using an electromagnetic induction sounder (EMIS) and ground penetrating radar (GPR). Both instruments probed the subsurface to a depth of approximately 3 m. Lateral EMIS soundings were performed every metre along a 400 m long reconnaissance line roughly oriented SW-NE and extending through 23 active springs and 1 dry outlet to measure electrical conductivity. Two distinct zones were identified within the survey area on the basis of these data: in the southwest portion, sharp conductivity peaks correspond to isolated springs with well-defined outlets, flowing over dry rocky soil; in the northeast portion, the springs are fed by a pervasive network of saline fluids, resulting in high background readings and muddy surface conditions. These observations are consistent with vertical EMIS sounding data which showed that the brine body feeding the saline springs can be found closer to the ground surface towards the northeast portion of the survey site. In areas of high electrical conductivity, the GPR data exhibits strong scattering. The noisy areas are sharply defined and interpreted to correspond to narrow vertical conduits feeding individual spring outlets. The EMIS is a rugged instrument that could be included as payload in future rover-based Mars exploration missions aiming at probing the shallow subsurface for the presence of brine pockets.

The significance of the subsurface in urban renewal

NARCIS (Netherlands)

Hooimeijer, F.L.; Maring, Linda

2018-01-01

The subsurface is a technical space, the “engine room of the city,” that incorporates the vital functions of water and energy supply, communication systems, sewers and drainage. Natural systems too – crucial for stable, dry, cool and nature inclusive cities – are also largely dependent on the

Soil salinization processes in rice irrigation schemes in the Senegal River Delta

International Nuclear Information System (INIS)

Ceuppens, J.; Wopereis, M.C.S.; Miezan, K.M.

1997-01-01

Soil salinization constitutes a major threat to irrigated agriculture (mainly rice, Oryza sativa L.) in the Senegal River Delta. It is generally hypothesized that salinization is caused by (i) capillary rise from a saline water table and (ii) concentration of salts in the field due to lack of adequate drainage facilities. The impact of field water management and rice cropping intensity on salinization in the Delta was determined using an electromagnetic conductivity meter (Geonics EM38). More than 4000 measurements were made in 40 rice fields on a typical heavy clay soil (Vertic Xerofluvent). Thirty EM38 measurements per field (0.25 ha) estimated average field soil salinity with a relative error of 20%. A multiple linear regression model based on EM38 readings explained 60 to 75% of the variability in conductivity of 1:5 saturation extracts at 0- to 5-, 10- to 15-, and 30- to 35-cm depths. Higher cropping intensity limited upward salt transport from the water table. Average horizontal and vertical EM38 measurements increased in the following order two rice crops per year with drainage: 0.73 and 0.98 dS m -1 ; one rice crop per year with drainage: 1.26 and 1.76 dS m -1 ; one rice crop per year without drainage: 2.23 and 2.98 dS m -1 ; and abandoned fields: 4.77 and 4.29 dS m -1 . Results indicate a beneficial effect of flooded rice on salinity for this type of heavy clay soil. Irrigation development in the area needs to be accompanied by monitoring of water table depth. (author)

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

Science.gov (United States)

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.

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

Science.gov (United States)

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.

Wetland Flow and Salinity Budgets and Elements of a Decision Support System toward Implementation of Real-Time Seasonal Wetland Salinity Management

Energy Technology Data Exchange (ETDEWEB)

Quinn, N.W.T.; Ortega, R.; Rahilly, P.; Johnson, C.B.

2011-12-17

The project has provided science-based tools for the long-term management of salinity in drainage discharges from wetlands to the San Joaquin River. The results of the project are being used to develop best management practices (BMP) and a decision support system to assist wetland managers adjust the timing of salt loads delivered to the San Joaquin River during spring drawdown. Adaptive drainage management scheduling has the potential to improve environmental compliance with salinity objectives in the Lower San Joaquin River by reducing the frequency of violation of Vernalis salinity standards, especially in dry and critically dry years. The paired approach to project implementation whereby adaptively managed and traditional practices were monitored in a side-by-side fashion has provided a quantitative measure of the impacts of the project on the timing of salt loading to the San Joaquin River. The most significant accomplishments of the project has been the technology transfer to wetland biologists, ditch tenders and water managers within the Grasslands Ecological Area. This “learning by doing” has build local community capacity within the Grassland Water District and California Department of Fish and Game providing these institutions with new capability to assess and effectively manage salinity within their wetlands while simultaneously providing benefits to salinity management of the San Joaquin River.

Estimating Leaching Requirements for Barley Growth under Saline Irrigation

Directory of Open Access Journals (Sweden)

Ahmed Al-Busaidi

2012-01-01

Full Text Available The utilization of marginal water resources for agriculture is receiving considerable attention. The lands irrigated with saline water are required to reduce salt accumulations through leaching and/or drainage practices. A field experiment was carried out to investigate the effect of saline irrigation and leaching fraction on barley (Hordeum vulgare L. growth. For this purpose highly saline water was diluted to the salinity levels of 3, 6 and 9 dS m-1 and applied by drip irrigation at 0.0, 0.15, 0.20 and 0.25 leaching fractions (LF. The results of the experiment showed that both quantity and quality of water regulated salts distribution within the soil in the following manner: a the salts were found higher near or immediate below the soil surface; b an enhanced LF carried more salts down the soil horizon but there was no significant difference in plant yield between different treatments of leaching fractions. Salinity of water significantly impaired barley growth. The good drainage of sandy soil enhanced the leaching process and minimized the differences between leaching fractions. The increment in saline treatments (3, 6 and 9 dS m-1 added more salts and stressed plant growth. However, the conjunctive use of marginal water at proportional LF could be effective in enhancing the yield potential of crops in water-scarce areas.

Irrigation management to optimize controlled drainage in a semi-arid area

OpenAIRE

Soppe, R.W.O.; Ayars, J.E.; Christen, E.W.; Shouse, P.J.

2003-01-01

On the west side of the San Joaquin Valley, California, groundwater tables have risen after several decades of irrigation. A regional semi-permeable layer at 100 m depth (Corcoran Clay) combined with over-irrigation and leaching is the major cause of the groundwater rise. Subsurface drain systems were installed from the 60¿s to the 80¿s to remove excess water and maintain an aerated root zone. However, drainage water resulting from these subsurface systems contained trace elements like seleni...

The formation of a subsurface anticyclonic eddy in the Peru-Chile Undercurrent and its impact on the near-coastal salinity, oxygen, and nutrient distributions

Science.gov (United States)

Thomsen, Soeren; Kanzow, Torsten; Krahmann, Gerd; Greatbatch, Richard J.; Dengler, Marcus; Lavik, Gaute

2016-01-01

The formation of a subsurface anticyclonic eddy in the Peru-Chile Undercurrent (PCUC) in January and February 2013 is investigated using a multiplatform four-dimensional observational approach. Research vessel, multiple glider, and mooring-based measurements were conducted in the Peruvian upwelling regime near 12°30'S. The data set consists of >10,000 glider profiles and repeated vessel-based hydrography and velocity transects. It allows a detailed description of the eddy formation and its impact on the near-coastal salinity, oxygen, and nutrient distributions. In early January, a strong PCUC with maximum poleward velocities of ˜0.25 m/s at 100-200 m depth was observed. Starting on 20 January, a subsurface anticyclonic eddy developed in the PCUC downstream of a topographic bend, suggesting flow separation as the eddy formation mechanism. The eddy core waters exhibited oxygen concentration of deficit of ˜17 μmol/L, and potential vorticity close to zero, which seemed to originate from the bottom boundary layer of the continental slope. The eddy-induced across-shelf velocities resulted in an elevated exchange of water masses between the upper continental slope and the open ocean. Small-scale salinity and oxygen structures were formed by along-isopycnal stirring, and indications of eddy-driven oxygen ventilation of the upper oxygen minimum zone were observed. It is concluded that mesoscale stirring of solutes and the offshore transport of eddy core properties could provide an important coastal open ocean exchange mechanism with potentially large implications for nutrient budgets and biogeochemical cycling in the oxygen minimum zone off Peru.

Drought-induced recharge promotes long-term storage of porewater salinity beneath a prairie wetland

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Levy, Zeno F.; Rosenberry, Donald O.; Moucha, Robert; Mushet, David M.; Goldhaber, Martin B.; LaBaugh, James W.; Fiorentino, Anthony J.; Siegel, Donald I.

2018-02-01

Subsurface storage of sulfate salts allows closed-basin wetlands in the semiarid Prairie Pothole Region (PPR) of North America to maintain moderate surface water salinity (total dissolved solids [TDS] from 1 to 10 g L-1), which provides critical habitat for communities of aquatic biota. However, it is unclear how the salinity of wetland ponds will respond to a recent shift in mid-continental climate to wetter conditions. To understand better the mechanisms that control surface-subsurface salinity exchanges during regional dry-wet climate cycles, we made a detailed geoelectrical study of a closed-basin prairie wetland (P1 in the Cottonwood Lake Study Area, North Dakota) that is currently experiencing record wet conditions. We found saline lenses of sulfate-rich porewater (TDS > 10 g L-1) contained in fine-grained wetland sediments 2-4 m beneath the bathymetric low of the wetland and within the currently ponded area along the shoreline of a prior pond stand (c. 1983). During the most recent drought (1988-1993), the wetland switched from a groundwater discharge to recharge function, allowing salts dissolved in surface runoff to move into wetland sediments beneath the bathymetric low of the basin. However, groundwater levels during this time did not decline to the elevation of the saline lenses, suggesting these features formed during more extended paleo-droughts and are stable in the subsurface on at least centennial timescales. We hypothesize a "drought-induced recharge" mechanism that allows wetland ponds to maintain moderate salinity under semiarid climate. Discharge of drought-derived saline groundwater has the potential to increase the salinity of wetland ponds during wet climate.

Effects of shallow groundwater management on the spatial and temporal variability of boron and salinity in an irrigated field

NARCIS (Netherlands)

Shouse, P.J.; Goldberg, S.; Skaggs, T.H.; Soppe, R.W.O.; Ayars, J.E.

2006-01-01

In some irrigated regions, the disposal of agricultural drainage waters poses significant environmental challenges. Efforts are underway to develop irrigation water management practices that reduce the volume of drainage generated. One such management strategy involves restricting flow in subsurface

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

Science.gov (United States)

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...

Abacus to determine soils salinity in presence of saline groundwater in arid zones case of the region of Ouargla

Science.gov (United States)

Fergougui, Myriam Marie El; Benyamina, Hind; Boutoutaou, Djamel

2018-05-01

In order to remedy the limit of salt intake to the soil surface, it is necessary to study the causes of the soil salinity and find the origin of these salts. The arid areas in the region of Ouargla lie on excessively mineralized groundwater whose level is near the soil surface (0 - 1.5 m). The topography and absence of a reliable drainage system led to the rise of the groundwater beside the arid climatic conditions contributed to the salinization and hydromorphy of the soils. The progress and stabilization of cultures yields in these areas can only occur if the groundwater is maintained (drained) to a depth of 1.6 m. The results of works done to the determination of soil salinity depend mainly on the groundwater's salinity, its depth and the climate.

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

Science.gov (United States)

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.

The removal of heavy metals by iron mine drainage sludge and Phragmites australis

Science.gov (United States)

Hoang Ha, Nguyen Thi; Anh, Bui Thi Kim

2017-06-01

This study was conducted to assess the removal of heavy metals from solutions by the combination of modified iron mine drainage sludge (sorbent column) and surface and subsurface flow constructed wetlands using the common reed (Phragmites australis) during 30 days of experiment. The results of this study demonstrated that the average removal rates of Zn, Pb, Mn, and As by sorbent column were 59.0, 55.1, 38.7, and 42.4%, respectively. The decreasing trend of removal rates of metals by sorbent column was obtained during the experiment. The average removal rates of Zn, Pb, Mn, and As by sorbent column-surface constructed wetland were 78.9, 73.5, 91.2, and 80.5%, respectively; those by sorbent column-subsurface flow constructed wetland were 81.7, 81.1, 94.1, and 83.1% which reflected that subsurface flow constructed wetland showed higher removal rate than the surface system. Concentrations of heavy metals in the outlet water were lower than the Vietnamese standard limits regulated for industrial wastewater. The results indicate the feasibility of integration of iron mine drainage sludge and constructed wetlands for wastewater treatment.

Effect of Different Alternate Irrigation Strategies using Saline and Non-Saline Water on Corn Yield, Salinity and Moisture Distribution in Soil Profile

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Ali Reza Kiani

2017-01-01

water in every other row, respectively; T5 and T6= fixed and variable deficit irrigation with non-saline water in every other rows, respectively and T7= full irrigation with saline water. To create the desired water salinity (8 dS/m, non-saline well water (1.5 dS/m and drainage water (20–35 dS/m were blended in different proportions. A T-tape drip irrigation system (20 m in length was used in the field experiment. Results and Discussion: In general, corn yield in 2013 was about 1270 kg ha-1 higher than in 2012. From the weather records it can be seen that the second year was drier than the first year. Yield analysis showed that deficit irrigation treatments (T2, T5 & T6 and also alternate salinity treatments (T3 & T4 did not significantly difference. In other words, the deficit irrigation management had no effect on yield. Corn yield in T3 and T4 with 50% of saved fresh water was just reduced to 7 and 1 % of T1, respectively. As a result, comparing treatments T3 and T4 with full irrigation have shown that treatments T3 and T4 are the best option. Comparison of moisture distribution in deficit irrigation treatments showed the highest water content in surface and deep layers was related to the treatments T6 and T2, respectively. The distribution of salinity in the soil profile for treatments T3 and T4 showed that after two years of irrigation with saline water, there is the possibility of use saline water for corn production, but drainage and leaching of soil will need to maintain sustainability. Conclusion: Naturally, in water scarce areas that use some strategic management such as deficit irrigation or saline water use, there is available arable farmland to further develop the irrigated area, and thereby increase total production. According to the results of the two-years where there was a shortage of water to meet crop water requirement and saline water was not available, the use of deficit irrigation managements as described in this study can save fresh water

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

Science.gov (United States)

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.

Nature of uranium contamination in the agricultural drainage water evaporation ponds of the San Joaquin Valley, California, USA

International Nuclear Information System (INIS)

Duff, M.C.; Amrhein, C.; Bradford, G.

1997-01-01

Evaporation ponds used for agricultural subsurface drainage water disposal in the Tulare Lake Bed (TLB) of the San Joaquin Valley, California, USA have elevated levels of U. Waterfowl which inhabit and forage the ponds and surrounding areas are threatened by exposure to U. The ponds, which receive irrigation drainage waters and seasonal rain, are subject to wetting and drying periods. The periods result in the accumulation of decaying algae and other organic material in surface sediments. Sediment and waters in the ponds were sampled to determine what factors control U solubility and sediment U concentrations. Data from a 1990 study conducted by Chilcott et al. in 1989 on the TLB ponds were used to help identify what factors may control U solubility. Pond sediment U concentrations decreased abruptly with depth and surface sediment U concentrations were related to dissolved Ca:HCO 3 ratios. Pond algal U bioaccumulation was favored in waters with high Ca:HCO 3 ratios, which had lower pH values and carbonate alkalinities than waters with low CA:HCO 3 ratios. Ponds with high salinities and high carbonate alkalinities contained the highest aqueous U concentrations relative to other TLB ponds. Sediment total organic carbon (TOC) was correlated with sediment U concentrations, suggesting that U is bound to organic matter. The source of TOC is most likely from algae deposition. (author)

Using the SIMGRO regional hydrological model to evaluate salinity control measures in an irrigation area

NARCIS (Netherlands)

Kupper, E.; Querner, E.P.; Morábito, J.A.; Menenti, M.

2002-01-01

In irrigated areas with drainage and an important interaction with the groundwater system, it is often difficult to predict effects of measures to control salinity. Therefore, in order to evaluate measures to control salinity the SIMGRO integrated regional hydrological model was extended with a

Remote Sensing Monitoring of Changes in Soil Salinity: A Case Study in Inner Mongolia, China

Directory of Open Access Journals (Sweden)

Jingwei Wu

2008-11-01

Full Text Available This study used archived remote sensing images to depict the history of changes in soil salinity in the Hetao Irrigation District in Inner Mongolia, China, with the purpose of linking these changes with land and water management practices and to draw lessons for salinity control. Most data came from LANDSAT satellite images taken in 1973, 1977, 1988, 1991, 1996, 2001, and 2006. In these years salt-affected areas were detected using a normal supervised classification method. Corresponding cropped areas were detected from NVDI (Normalized Difference Vegetation Index values using an unsupervised method. Field samples and agricultural statistics were used to estimate the accuracy of the classification. Historical data concerning irrigation/drainage and the groundwater table were used to analyze the relation between changes in soil salinity and land and water management practices. Results showed that: (1 the overall accuracy of remote sensing in detecting soil salinity was 90.2%, and in detecting cropped area, 98%; (2 the installation/innovation of the drainage system did help to control salinity; and (3 a low ratio of cropped land helped control salinity in the Hetao Irrigation District. These findings suggest that remote sensing is a useful tool to detect soil salinity and has potential in evaluating and improving land and water management practices.

Remote Sensing Monitoring of Changes in Soil Salinity: A Case Study in Inner Mongolia, China.

Science.gov (United States)

Wu, Jingwei; Vincent, Bernard; Yang, Jinzhong; Bouarfa, Sami; Vidal, Alain

2008-11-07

This study used archived remote sensing images to depict the history of changes in soil salinity in the Hetao Irrigation District in Inner Mongolia, China, with the purpose of linking these changes with land and water management practices and to draw lessons for salinity control. Most data came from LANDSAT satellite images taken in 1973, 1977, 1988, 1991, 1996, 2001, and 2006. In these years salt-affected areas were detected using a normal supervised classification method. Corresponding cropped areas were detected from NVDI (Normalized Difference Vegetation Index) values using an unsupervised method. Field samples and agricultural statistics were used to estimate the accuracy of the classification. Historical data concerning irrigation/drainage and the groundwater table were used to analyze the relation between changes in soil salinity and land and water management practices. Results showed that: (1) the overall accuracy of remote sensing in detecting soil salinity was 90.2%, and in detecting cropped area, 98%; (2) the installation/innovation of the drainage system did help to control salinity; and (3) a low ratio of cropped land helped control salinity in the Hetao Irrigation District. These findings suggest that remote sensing is a useful tool to detect soil salinity and has potential in evaluating and improving land and water management practices.

Pleural fluid drainage: Percutaneous catheter drainage versus surgical chest tube drainage

International Nuclear Information System (INIS)

Illescas, F.F.; Reinhold, C.; Atri, M.; Bret, P.M.

1987-01-01

Over the past 4 years, 55 cases (one transudate, 28 exudates, and 26 empymas) were drained. Surgical chest tubes alone were used in 35 drainages, percutaneous catheters alone in five drainages, and both types in 15 drainages. Percutaneous catheter drainage was successful in 12 of 20 drainages (60%). Surgical tube drainage was successful in 18 of 50 drainages (36%). The success rate for the nonempyema group was 45% with both types of drainage. For the empyema group, the success rate for percutaneous catheter drainage was 66% vs 23% for surgical tube drainage. Seven major complications occurred with surgical tube drainage, but only one major complication occurred with percutaneous catheter drainage. Radiologically guided percutaneous catheter drainage should be the procedure of choice for pleural fluid drainage. It has a higher success rate for empyemas and is associated with less complications

Salinization and Saline Environments

Science.gov (United States)

Vengosh, A.

2003-12-01

, such as treated wastewater and agricultural drainage water. Two anthropogenic salinization cycles are introduced - the agricultural and the domestic cycles. Some useful geochemical fingerprinting tracers are also included for defining the sources of salinity. Finally, the chemical composition of future water resources is predicted, based on the chemical and isotopic fractionation associated with remediation and desalination.

Irrigation salinity hazard assessment and risk mapping in the lower Macintyre Valley, Australia.

Science.gov (United States)

Huang, Jingyi; Prochazka, Melissa J; Triantafilis, John

2016-05-01

In the Murray-Darling Basin of Australia, secondary soil salinization occurs due to excessive deep drainage and the presence of shallow saline water tables. In order to understand the cause and best management, soil and vadose zone information is necessary. This type of information has been generated in the Toobeah district but owing to the state border an inconsistent methodology was used. This has led to much confusion from stakeholders who are unable to understand the ambiguity of the results in terms of final overall risk of salinization. In this research, a digital soil mapping method that employs various ancillary data is presented. Firstly, an electromagnetic induction survey using a Geonics EM34 and EM38 was used to characterise soil and vadose zone stratigraphy. From the apparent electrical conductivity (ECa) collected, soil sampling locations were selected and with laboratory analysis carried out to determine average (2-12m) clay and EC of a saturated soil-paste extract (ECe). EM34 ECa, land surface parameters derived from a digital elevation model and measured soil data were used to establish multiple linear regression models, which allowed for mapping of various hazard factors, including clay and ECe. EM38 ECa data were calibrated to deep drainage obtained from Salt and Leaching Fraction (SaLF) modelling of soil data. Expert knowledge and indicator kriging were used to determine critical values where the salinity hazard factors were likely to contribute to a shallow saline water table (i.e., clay ≤35%; ECe>2.5dS/m, and deep drainage >100mm/year). This information was combined to produce an overall salinity risk map for the Toobeah district using indicator kriging. The risk map shows potential salinization areas and where detailed information is required and where targeted research can be conducted to monitor soil conditions and water table heights and determine best management strategies. Copyright © 2016 Elsevier B.V. All rights reserved.

Effects of surface and subsurface drip irrigation regimes with saline water on yield and water use efficiency of potato in arid conditions of Tunisia

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Fathia El Mokh

2014-12-01

Full Text Available Field experiments were conducted on a sandy soil during spring of 2009 and autumn of 2010 in southern Tunisia for evaluating the effects of two drip irrigation methods and three irrigation regimes on soil moisture and salinity, yield and water use efficiency of potato (Solanum tuberosum L.. The surface drip (SDI and subsurface drip (SSDI irrigation methods were used. Irrigation regimes consisted in replacement of cumulated ETc when readily available water is depleted with levels of 100% (FI100, 60% (DI60 and 30% (DI30. FI100 was considered as full irrigation while DI60 and DI30 were considered as deficit irrigation regimes. Well water with an ECi of 7.0 dS/m was used for irrigation. Findings are globally consistent between the two experiments. Results show that soil moisture content and salinity were significantly affected by irrigation treatments and methods. Higher soil moisture content and lower soil salinity were maintained with SSDI than SDI for all irrigation treatments. For both irrigation methods, higher salinity and lower moisture content in the root zone are observed under DI60 and DI30 treatments compared to FI100. Potato yields were highest over two cropping periods for the SSDI method although no significant differences were observed with the SDI. Irrigation regimes resulted in significant difference in both irrigation methods on yield and its components. Yields were highest under FI100. Compared to FI100, considerable reductions in potato yields were observed under DI60 and DI30 deficit treatments resulting from a reduction in tubers number/m² and average tuber weight and size. Water use efficiency (WUE was found to vary significantly among irrigation methods and treatments and varied between 5.9 and 20.5 kg/m3. WUE of SSDI method had generally higher values than SDI. The lowest WUE values were observed for the FI100 treatment, while the highest values were obtained under DI30 treatment for both methods. SSDI method provides

Evaluation of Critical Parameters to Improve Slope Drainage System

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Yong Weng Long

2017-01-01

Full Text Available This study focuses on identifying and evaluating critical parameters of various drainage configurations, arrangement, and filter which affect the efficiency of water draining system in slopes. There are a total of seven experiments with different types of homogeneous soil, drainage envelope, filter material, and quantity of pipes performed utilizing a model box with a dimension of 0.8 m × 0.8 m × 0.6 m. The pipes were orientated at 5 degrees from the horizontal. Rainfall event was introduced via a rainfall simulator with rainfall intensity of 434.1 mm/h. From the experiments performed, the expected outcomes when utilizing double pipes and geotextile as envelope filter were verified in this study. The results obtained from these experiments were reviewed and compared with Chapter 14 “Subsurface Drainage Systems” of DID’s Irrigation and Agricultural Drainage Manual of Malaysia and the European standard. It is recommended that the pipe installed in the slope could be wrapped with geotextile and in tandem with application of granular filter to minimize clogging without affecting the water discharge rate. Terzaghi’s filter criteria could be followed closely when deciding on new materials to act as aggregate filter. A caging system could be introduced as it could maintain the integrity of the drainage system and could ease installation.

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

Science.gov (United States)

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.

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

Science.gov (United States)

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 salinity on freshwater fishes in coastal plain drainages in the southeastern U.S.

Science.gov (United States)

Peterson, Mark S.; Meador, Michael R.

1994-01-01

This review focuses on the influence of salinity on freshwater fishes in coastal rivers and estuaries of the southeastern U.S. Influences of salinity on freshwater fish species can be explained partly through responses evidenced by behavior, physiology, growth, reproduction, and food habits during all aspects of life history. Factors influencing the rate of salinity change affect the community structure and dynamics of freshwater fishes in brackish environments. Our understanding of the relation between salinity and the life history of freshwater fishes is limited because little ecological research has been conducted in low-salinity habitats that we consider an “interface” between freshwater streams and the estuary proper. Much of the available data are descriptive in nature and describe best general patterns, but more specific studies are required to better determine the influence of salinity on freshwater fishes. Improved understanding of the influence of human-induced changes on the productivity and viability of these important systems will require a new research focus.

Recent trends in salinity control for soilless growing systems management

NARCIS (Netherlands)

Katsoulas, N.; Voogt, W.

2014-01-01

The consequences of closed hydroponic systems, the impact of salinity build-up on crop yield and product quality are reviewed. Soilless cultivation, especially in closed-loop systems offers a great option for water saving in greenhouses. Capture and recycling of the drainage will considerably

Evolution of Planetary Ice-Ocean Systems: Effects of Salinity

Science.gov (United States)

Allu Peddinti, D.; McNamara, A. K.

2015-12-01

Planetary oceanography is enjoying renewed attention thanks to not only the detection of several exoplanetary ocean worlds but also due to the expanding family of ocean worlds within our own star system. Our solar system is now believed to host about nine ocean worlds including Earth, some dwarf planets and few moons of Jupiter and Saturn. Amongst them, Europa, like Earth is thought to have an ice Ih-liquid water system. However, the thickness of the Europan ice-ocean system is much larger than that of the Earth. The evolution of this system would determine the individual thicknesses of the ice shell and the ocean. In turn, these thicknesses can alter the course of evolution of the system. In a pure H2O system, the thickness of the ice shell would govern if heat loss occurs entirely by conduction or if the shell begins to convect as it attains a threshold thickness. This switch between conduction-convection regimes could determine the longevity of the subsurface ocean and hence define the astrobiological potential of the planetary body at any given time. In reality, however, the system is not pure water ice. The detected induced magnetic field infers a saline ocean layer. Salts are expected to act as an anti-freeze allowing a subsurface ocean to persist over long periods but the amount of salts would determine the extent of that effect. In our current study, we use geodynamic models to examine the effect of salinity on the evolution of ice-ocean system. An initial ocean with different salinities is allowed to evolve. The effect of salinity on thickness of the two layers at any time is examined. We also track how salinity controls the switch between conductive-convective modes. The study shows that for a given time period, larger salinities can maintain a thick vigorously convecting ocean while the smaller salinities behave similar to a pure H2O system leading to a thick convecting ice-shell. A range of salinities identified can potentially predict the current state

Joint inversion of geophysical and hydrological data for improved subsurface characterization

International Nuclear Information System (INIS)

Kowalsky, Michael B.; Chen, Jinsong; Hubbard, Susan S.

2006-01-01

Understanding fluid distribution and movement in the subsurface is critical for a variety of subsurface applications, such as remediation of environmental contaminants, sequestration of nuclear waste and CO2, intrusion of saline water into fresh water aquifers, and the production of oil and gas. It is well recognized that characterizing the properties that control fluids in the subsurface with the accuracy and spatial coverage needed to parameterize flow and transport models is challenging using conventional borehole data alone. Integration of conventional borehole data with more spatially extensive geophysical data (obtained from the surface, between boreholes, and from surface to boreholes) shows promise for providing quantitative information about subsurface properties and processes. Typically, estimation of subsurface properties involves a two-step procedure in which geophysical data are first inverted and then integrated with direct measurements and petrophysical relationship information to estimate hydrological parameters. However, errors inherent to geophysical data acquisition and inversion approaches and errors associated with petrophysical relationships can decrease the value of geophysical data in the estimation procedure. In this paper, we illustrate using two examples how joint inversion approaches, or simultaneous inversion of geophysical and hydrological data, offer great potential for overcoming some of these limitations

Crop and irrigation management strategies for saline-sodic soils and waters aimed at environmentally sustainable agriculture.

Science.gov (United States)

Qadir, M; Oster, J D

2004-05-05

Irrigation has long played a key role in feeding the expanding world population and is expected to play a still greater role in the future. As supplies of good-quality irrigation water are expected to decrease in several regions due to increased municipal-industrial-agricultural competition, available freshwater supplies need to be used more efficiently. In addition, reliance on the use and reuse of saline and/or sodic drainage waters, generated by irrigated agriculture, seems inevitable for irrigation. The same applies to salt-affected soils, which occupy more than 20% of the irrigated lands, and warrant attention for efficient, inexpensive and environmentally acceptable management. Technologically and from a management perspective, a couple of strategies have shown the potential to improve crop production under irrigated agriculture while minimizing the adverse environmental impacts. The first strategy, vegetative bioremediation--a plant-assisted reclamation approach--relies on growing appropriate plant species that can tolerate ambient soil salinity and sodicity levels during reclamation of salt-affected soils. A variety of plant species of agricultural significance have been found to be effective in sustainable reclamation of calcareous and moderately sodic and saline-sodic soils. The second strategy fosters dedicating soils to crop production systems where saline and/or sodic waters predominate and their disposal options are limited. Production systems based on salt-tolerant plant species using drainage waters may be sustainable with the potential of transforming such waters from an environmental burden into an economic asset. Such a strategy would encourage the disposal of drainage waters within the irrigated regions where they are generated rather than exporting these waters to other regions via discharge into main irrigation canals, local streams, or rivers. Being economically and environmentally sustainable, these strategies could be the key to future

Wetland Plant Guide for Assessing Habitat Impacts of Real-Time Salinity Management

OpenAIRE

Quinn, Nigel W.T.; Feldmann, Sara A.

2004-01-01

This wetland plant guide was developed to aid moist soil plant identification and to assist in the mapping of waterfowl and shorebird habitat in the Grassland Water District and surrounding wetland areas. The motivation for this habitat mapping project was a concern that real-time salinity management of wetland drainage might have long-term consequences for wildfowl habitat health -- changes in wetland drawdown schedules might, over the long term, lead to increased soil salinity and othe...

Estimation of Tile Drainage Contribution to Streamflow and Nutrient Export Loads

Science.gov (United States)

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.

Reclaiming agricultural drainage water with nanofiltration membranes: Imperial Valley, California, USA

Science.gov (United States)

Kharaka, Y.K.; Schroeder, R.A.; Setmire, J.G.; ,

2003-01-01

We conducted pilot-scale field experiments using nanofiltration membranes to lower the salinity and remove Se, As and other toxic contaminants from saline agricultural wastewater in the Imperial Valley, California, USA. Farmlands in the desert climate (rainfall - 7.4 cm/a) of Imperial Valley cover -200,000 ha that are irrigated with water (-1.7 km3 annually) imported from the Colorado River. The salinity (-850 mg/L) and concentration of Se (-2.5 ??g/L) in the Colorado River water are high and evapotranpiration further concentrates salts in irrigation drainage water, reaching salinities of 3,000-15,000 mg/L TDS and a median Se value of -30 ??g/L. Experiments were conducted with two commercially available nanofiltration membranes, using drainage water of varying composition, and with or without the addition of organic precipitation inhibitors. Results show that these membranes selectively remove more than 95% of Se, SO4, Mo, U and DOC, and -30% of As from this wastewater. Low percentages of Cl, NO3 and HCO3, with enough cations to maintain electrical neutrality also were removed. The product water treated by these membranes comprised more than 90% of the wastewater tested. Results indicate that the treated product water from the Alamo River likely will have less than 0.2 ??g/L Se, salinity of 300-500 mg/L TDS and other chemical concentrations that meet the water quality criteria for irrigation and potable use. Because acceptability is a major issue for providing treated wastewater to urban centers, it may be prudent to use the reclaimed water for irrigation and creation of lower salinity wetlands near the Salton Sea; an equivalent volume of Colorado River water can then be diverted for the use of increasing populations of San Diego and other urban centers in southern California. Nanofiltration membranes yield greater reclaimed-water output and require lower pressure and less pretreatment, and therefore are generally more cost effective than traditional reverse

Long-term monitoring of nitrate transport to drainage from three agricultural clayey till fields

DEFF Research Database (Denmark)

Ernstsen, Vibeke; Olsen, Preben; Rosenbom, Annette E.

2015-01-01

-regulation in future. This study strives to provide such knowledge by evaluating on 11 years of nitrate-N con-centration measurements in drainage from three subsurface-drained clayey till fields (1.3–2.3 ha) representing approxi-mately 71 % of the surface sediments in Denmark dominated by clay. The fields differ...... in their inherent hydrogeological field settings (e.g. soil-type, geology, climate, drainage and groundwater table) and the agricultural management of the fields (e.g. crop type, type of N fertilisers and agricultural practices). The evaluation revealed three types of clayey till fields characterised by: (i) low net...... precipitation, high concen-tration of nitrate-N, and short-term low intensity drainage at air temperatures often below 5 ◦C; (ii) medium net precip-itation, medium concentration of nitrate-N, and short-term medium-intensity drainage at air temperatures often above 5 ◦C; and (iii) high net precipitation, low...

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

Science.gov (United States)

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 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.

Estimation of Recharge from Long-Term Monitoring of Saline Tracer Transport Using Electrical Resistivity Tomography

DEFF Research Database (Denmark)

Haarder, Eline Bojsen; Jensen, Karsten Høgh; Binley, Andrew

2015-01-01

The movement of a saline tracer added to the soil surface was monitored in the unsaturated zone using cross-borehole electrical resistivity tomography (ERT) and subjected to natural rainfall conditions. The ERT data were inverted and corrected for subsurface temperature changes, and spatial moment...... methods. In September 2011, a saline tracer was added across a 142-m2 area at the surface at an application rate mimicking natural infiltration. The movement of the saline tracer front was monitored using cross-borehole electrical resistivity tomography (ERT); data were collected on a daily to weekly...

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

Science.gov (United States)

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.

Quantitative scintigraphy analysis of the normal lacrimal drainage using 99mTc radioisotope

International Nuclear Information System (INIS)

Bittar, Marcos Daniel Ramos.

1994-01-01

The dynamics of the lacrimal drainage system was studied in 37 normal patients including 16 males and 21 females by means of a radioisotope 99m Tc (technetium as pertechnetate in a normal saline solution), a gamma camera and a computer. After instillation of 10 μl normal saline solution containing 99m Tc in the conjunctival sac a scintigram was taken at the beginning and at the end of 10 minutes measuring time and images were recorded every 5 seconds. Two areas were studied: conjunctival and lacrimal sac. 39 refs., 17 figs., 1 tab

Aspects to consider for optimizing a substrate culture system with drainage recycling

Directory of Open Access Journals (Sweden)

William J Cuervo B

2012-09-01

Full Text Available In Colombia, the soilless system has been implemented in the cut flowers industry, among others, due to soil limitations. The use of substrates as growing media implies to drain around 30% of the applied fertigation solution to avoid the rhizosphere salinization. The drainage solution is spilled out to the soil producing environmental hazards and it might reach the water table; although the drainage solution could be recycled or reuse, depending upon their chemical characteristics. The nutrient uptake by the plants depends upon their phenological stage and the nutrient concentration in the solution; which could lead to ion depletion or accumulation. In general, monovalent ions are withdrawn faster than divalent ones. An efficient drainage treatment involves the automation of sensing and evaluation of ion concentration and recycling the drainage solution. The system should take into account the chemical aspects in the recycled and the new solutions in order to predict the life time of the drainage solution from their EC and pH. The system must be integrated with disinfection methods to avoid the spreading of plant pathogens. This review point out the physiological and technical bases that should be taking into account in a drainage recycling system in established crops under substrates, as a tool to take decisions more efficiently.

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

Science.gov (United States)

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.

Hydrogeochemistry and microbiology of mine drainage: An update

Science.gov (United States)

Nordstrom, D. Kirk; Blowes, D.W; Ptacek, C.J.

2015-01-01

The extraction of mineral resources requires access through underground workings, or open pit operations, or through drillholes for solution mining. Additionally, mineral processing can generate large quantities of waste, including mill tailings, waste rock and refinery wastes, heap leach pads, and slag. Thus, through mining and mineral processing activities, large surface areas of sulfide minerals can be exposed to oxygen, water, and microbes, resulting in accelerated oxidation of sulfide and other minerals and the potential for the generation of low-quality drainage. The oxidation of sulfide minerals in mine wastes is accelerated by microbial catalysis of the oxidation of aqueous ferrous iron and sulfide. These reactions, particularly when combined with evaporation, can lead to extremely acidic drainage and very high concentrations of dissolved constituents. Although acid mine drainage is the most prevalent and damaging environmental concern associated with mining activities, generation of saline, basic and neutral drainage containing elevated concentrations of dissolved metals, non-metals, and metalloids has recently been recognized as a potential environmental concern. Acid neutralization reactions through the dissolution of carbonate, hydroxide, and silicate minerals and formation of secondary aluminum and ferric hydroxide phases can moderate the effects of acid generation and enhance the formation of secondary hydrated iron and aluminum minerals which may lessen the concentration of dissolved metals. Numerical models provide powerful tools for assessing impacts of these reactions on water quality.

Water masses in the Humboldt Current System: Properties, distribution, and the nitrate deficit as a chemical water mass tracer for Equatorial Subsurface Water off Chile

Science.gov (United States)

Silva, Nelson; Rojas, Nora; Fedele, Aldo

2009-07-01

Three sections are used to analyze the physical and chemical characteristics of the water masses in the eastern South Pacific and their distributions. Oceanographic data were taken from the SCORPIO (May-June 1967), PIQUERO (May-June 1969), and KRILL (June 1974) cruises. Vertical sections of temperature, salinity, σ θ, dissolved oxygen, nitrate, nitrite, phosphate, and silicate were used to analyze the water column structure. Five water masses were identified in the zone through T- S diagrams: Subantarctic Water, Subtropical Water, Equatorial Subsurface Water, Antarctic Intermediate Water, and Pacific Deep Water. Their proportions in the sea water mixture are calculated using the mixing triangle method. Vertical sections were used to describe the geographical distributions of the water mass cores in the upper 1500 m. Several characteristic oceanographic features in the study area were analyzed: the shallow salinity minimum displacement towards the equator, the equatorial subsurface salinity maximum associated with a dissolved oxygen minimum zone and a high nutrient content displacement towards the south, and the equatorward intermediate Antarctic salinity minimum associated with a dissolved oxygen maximum. The nitrate deficit generated in the denitrification area off Peru and northern Chile is proposed as a conservative chemical tracer for the Equatorial Subsurface Waters off the coast of Chile, south of 25°S.

Salinity management in southern Italy irrigation areas

Directory of Open Access Journals (Sweden)

Massimo Monteleone

Full Text Available After a synthetic review of the most worrisome pressures applied over soils and waters, general criterions and normative principles that have to lead the technical intervention on soil and water protection are accounted, both with respect to farm activity and land planning. The salinity problem is faced, then, through the analysis of the nature and origin of saline soil and of the complex quantitative relationships able to interpret the accumulation and leaching of soil salts. Having specified the theoretical bases of salinity, the related technical features are then considered in order to define a proper management of soil and waters. Particular relevance is assigned to the irrigation and leaching techniques as well as, more briefly, to other agronomic interventions in order to guarantee the most effective salinity control. Another relevant technical facet of salinity control, although quite often neglected or retained of secondary importance in comparison to irrigation, is the drainage and disposal of leached water. The increased sensibility on the environmental impacts that the disposal of these waters can produce has raised today the level of attention on these procedures that are disciplined by norms of law and, therefore, require appropriate techniques of intervention. Finally, after the different scale orders involved in the management of salinity are defined (from the field and farm level up to the land and basin, the fundamental elements in order to work out a risk analysis and an action program are illustrated; some indications about the most up to date salinity monitoring and mapping methods are also provided, considering their great importance to continuously check the possible broadening of salinization and to carefully maintain its control.

Deep subsurface drip irrigation using coal-bed sodic water: part I. water and solute movement

Science.gov (United States)

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.

Remote sensing of wet lands in irrigated areas

Science.gov (United States)

Ham, H. H.

1972-01-01

The use of airborne remote sensing techniques to: (1) detect drainage problem areas, (2) delineate the problem in terms of areal extent, depth to the water table, and presence of excessive salinity, and (3) evaluate the effectiveness of existing subsurface drainage facilities, is discussed. Experimental results show that remote sensing, as demonstrated in this study and as presently constituted and priced, does not represent a practical alternative as a management tool to presently used visual and conventional photographic methods in the systematic and repetitive detection and delineation of wetlands.

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

Science.gov (United States)

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 soil. Further study is warranted to confirm the mechanisms involved and quantities of Cd lost from other systems.

Saline agriculture: A technology for economic utilization and improvement of saline environments (abstract)

International Nuclear Information System (INIS)

Aslam, Z.; Malik, K.A.; Khurshid, S.J.; Awan, A.R.; Akram, M.; Hashmi, Z.; Ali, Y.; Gulnaz, A.; Hussain, M.; Hussain, F.

2005-01-01

The salinity problem is one of the severe constraints for agriculture in Pakistan. In a socio-economic and salinity and drainage survey over an area of about 25000 acres of salt-affected land recently, crop production is found to be very low. Livestock is underfed and malnourished. Pakistan has spent and allocated over one billion US dollars on Salinity Control and Reclamation Projects (SCARP), of course, with dubious results. Over the years, a Saline Agriculture Technology has been developed as a cheap alternative at NIAB for comfortably living with salinity and to profitably utilize saline land rather than its reclamation. The soil improvement is a fringe benefit in this approach. The Saline Agriculture Technology has been tested at laboratory level, at field stations and at farms of some progressive farmers. Now we are sharing this technology with farming communities through a 'Saline Agriculture Farmer Participatory Development Project in Pakistan', with assistance from the National Rural Support Programme. The new project has been launched simultaneously in all four provinces of Pakistan on 25000 acres of salt-affected land. Under this project seeds of salt tolerant crop varieties wheat, cotton, rice, castor, brassica and barley and saplings of trees/shrubs, e.g. Acacia ampliceps, A. nilotica, Casuarina glauca, ber, jaman, etc selected for development work in various institutions of Pakistan are being provided to farmers. Know-how on new irrigation techniques like bed-and-corrugation and bed-and-furrow, agronomic practices like laser land leveling, planting on beds and in auger holes and soil/water amendment practices (use of gypsum and mineral acids) are being shared with farmers. These interventions are quite efficient, save water up to 40% and enable farmers to utilize bad quality water. In general, farmers are being familiarized with prevalent animal diseases, nutritional problems and prophylactic techniques. They are being helped in developing Saline

Saline water intrusion toward groundwater: Issues and its control

Directory of Open Access Journals (Sweden)

Purnama S

2012-10-01

Full Text Available Nowadays, saline water pollution has been gaining its importance as the major issue around the world, especially in the urban coastal area. Saline water pollution has major impact on human life and livelihood. It ́s mainly a result from static fossil water and the dynamics of sea water intrusion. The problem of saline water pollution caused by seawater intrusion has been increasing since the beginning of urban population. The problem of sea water intrusion in the urban coastal area must be anticipated as soon as possible especially in the urban areas developed in coastal zones,. This review article aims to; (i analyze the distribution of saline water pollution on urban coastal area in Indonesia and (ii analyze some methods in controlling saline water pollution, especially due to seawater intrusion in urban coastal area. The strength and weakness of each method have been compared, including (a applying different pumping patterns, (b artificial recharge, (c extraction barrier, (d injection barrier and (e subsurface barrier. The best method has been selected considering its possible development in coastal areas of developing countries. The review is based considering the location of Semarang coastal area, Indonesia. The results have shown that artificial recharge and extraction barrier are the most suitable methods to be applied in the area.

Full-waveform modeling of Zero-Offset Electromagnetic Induction for Accurate Characterization of Subsurface Electrical Properties

Science.gov (United States)

Moghadas, D.; André, F.; Vereecken, H.; Lambot, S.

2009-04-01

Water is a vital resource for human needs, agriculture, sanitation and industrial supply. The knowledge of soil water dynamics and solute transport is essential in agricultural and environmental engineering as it controls plant growth, hydrological processes, and the contamination of surface and subsurface water. Increased irrigation efficiency has also an important role for water conservation, reducing drainage and mitigating some of the water pollution and soil salinity. Geophysical methods are effective techniques for monitoring the vadose zone. In particular, electromagnetic induction (EMI) can provide in a non-invasive way important information about the soil electrical properties at the field scale, which are mainly correlated to important variables such as soil water content, salinity, and texture. EMI is based on the radiation of a VLF EM wave into the soil. Depending on its electrical conductivity, Foucault currents are generated and produce a secondary EM field which is then recorded by the EMI system. Advanced techniques for EMI data interpretation resort to inverse modeling. Yet, a major gap in current knowledge is the limited accuracy of the forward model used for describing the EMI-subsurface system, usually relying on strongly simplifying assumptions. We present a new low frequency EMI method based on Vector Network Analyzer (VNA) technology and advanced forward modeling using a linear system of complex transfer functions for describing the EMI loop antenna and a three-dimensional solution of Maxwell's equations for wave propagation in multilayered media. VNA permits simple, international standard calibration of the EMI system. We derived a Green's function for the zero-offset, off-ground horizontal loop antenna and also proposed an optimal integration path for faster evaluation of the spatial-domain Green's function from its spectral counterpart. This new integration path shows fewer oscillations compared with the real path and permits to avoid the

Modelling soil salinity in Oued El Abid watershed, Morocco

Science.gov (United States)

Mouatassime Sabri, El; Boukdir, Ahmed; Karaoui, Ismail; Arioua, Abdelkrim; Messlouhi, Rachid; El Amrani Idrissi, Abdelkhalek

2018-05-01

Soil salinisation is a phenomenon considered to be a real threat to natural resources in semi-arid climates. The phenomenon is controlled by soil (texture, depth, slope etc.), anthropogenic factors (drainage system, irrigation, crops types, etc.), and climate factors. This study was conducted in the watershed of Oued El Abid in the region of Beni Mellal-Khenifra, aimed at localising saline soil using remote sensing and a regression model. The spectral indices were extracted from Landsat imagery (30 m resolution). A linear correlation of electrical conductivity, which was calculated based on soil samples (ECs), and the values extracted based on spectral bands showed a high accuracy with an R2 (Root square) of 0.80. This study proposes a new spectral salinity index using Landsat bands B1 and B4. This hydro-chemical and statistical study, based on a yearlong survey, showed a moderate amount of salinity, which threatens dam water quality. The results present an improved ability to use remote sensing and regression model integration to detect soil salinity with high accuracy and low cost, and permit intervention at an early stage of salinisation.

Towards monitoring surface and subsurface lakes on the Greenland Ice Sheet using Sentinel-1 SAR and Landsat-8 OLI imagery

Science.gov (United States)

Miles, Katie E.; Willis, Ian C.; Benedek, Corinne L.; Williamson, Andrew G.; Tedesco, Marco

2017-07-01

Supraglacial lakes are an important component of the Greenland Ice Sheet’s mass balance and hydrology, with their drainage affecting ice dynamics. This study uses imagery from the recently launched Sentinel-1A Synthetic Aperture Radar (SAR) satellite to investigate supraglacial lakes in West Greenland. A semi-automated algorithm is developed to detect surface lakes from Sentinel-1 images during the 2015 summer. A combined Landsat-8 and Sentinel-1 dataset, which has a comparable temporal resolution to MODIS (3 days versus daily) but a higher spatial resolution (25-40 m versus 250-500 m), is then used together with a fully-automated lake drainage detection algorithm. Rapid (days) and slow (> 4 days) drainages are investigated for both small (summer. Drainage events of small lakes occur at lower elevations (mean 159 m), and slightly earlier (mean 4.5 days) in the melt season than those of large lakes. The analysis is extended manually into the early winter to calculate the dates and elevations of lake freeze-through more precisely than is possible with optical imagery (mean 30 August; 1270 m mean elevation). Finally, the Sentinel-1 imagery is used to detect subsurface lakes and, for the first time, their dates of appearance and freeze-through (mean 9 August and 7 October, respectively). These subsurface lakes occur at higher elevations than the surface lakes detected in this study (mean 1593 m and 1185 m, respectively). Sentinel-1 imagery therefore provides great potential for tracking melting, water movement and freezing within both the firn zone and ablation area of the Greenland Ice Sheet.

Freshwater salinization syndrome on a continental scale.

Science.gov (United States)

Kaushal, Sujay S; Likens, Gene E; Pace, Michael L; Utz, Ryan M; Haq, Shahan; Gorman, Julia; Grese, Melissa

2018-01-23

Salt pollution and human-accelerated weathering are shifting the chemical composition of major ions in fresh water and increasing salinization and alkalinization across North America. We propose a concept, the freshwater salinization syndrome, which links salinization and alkalinization processes. This syndrome manifests as concurrent trends in specific conductance, pH, alkalinity, and base cations. Although individual trends can vary in strength, changes in salinization and alkalinization have affected 37% and 90%, respectively, of the drainage area of the contiguous United States over the past century. Across 232 United States Geological Survey (USGS) monitoring sites, 66% of stream and river sites showed a statistical increase in pH, which often began decades before acid rain regulations. The syndrome is most prominent in the densely populated eastern and midwestern United States, where salinity and alkalinity have increased most rapidly. The syndrome is caused by salt pollution (e.g., road deicers, irrigation runoff, sewage, potash), accelerated weathering and soil cation exchange, mining and resource extraction, and the presence of easily weathered minerals used in agriculture (lime) and urbanization (concrete). Increasing salts with strong bases and carbonates elevate acid neutralizing capacity and pH, and increasing sodium from salt pollution eventually displaces base cations on soil exchange sites, which further increases pH and alkalinization. Symptoms of the syndrome can include: infrastructure corrosion, contaminant mobilization, and variations in coastal ocean acidification caused by increasingly alkaline river inputs. Unless regulated and managed, the freshwater salinization syndrome can have significant impacts on ecosystem services such as safe drinking water, contaminant retention, and biodiversity. Copyright © 2018 the Author(s). Published by PNAS.

Simulation of integrated surface-water/ground-water flow and salinity for a coastal wetland and adjacent estuary

Science.gov (United States)

Langevin, C.; Swain, E.; Wolfert, M.

2005-01-01

The SWIFT2D surface-water flow and transport code, which solves the St Venant equations in two dimensions, was coupled with the SEAWAT variable-density ground-water code to represent hydrologic processes in coastal wetlands and adjacent estuaries. A sequentially coupled time-lagged approach was implemented, based on a variable-density form of Darcy's Law, to couple the surface and subsurface systems. The integrated code also represents the advective transport of salt mass between the surface and subsurface. The integrated code was applied to the southern Everglades of Florida to quantify flow and salinity patterns and to evaluate effects of hydrologic processes. Model results confirm several important observations about the coastal wetland: (1) the coastal embankment separating the wetland from the estuary is overtopped only during tropical storms, (2) leakage between the surface and subsurface is locally important in the wetland, but submarine ground-water discharge does not contribute large quantities of freshwater to the estuary, and (3) coastal wetland salinities increase to near seawater values during the dry season, and the wetland flushes each year with the onset of the wet season. ?? 2005 Elsevier B.V. All rights reserved.

Estimation of soil salinity in a drip irrigation system by using joint inversion of multicoil electromagnetic induction measurements

KAUST Repository

Jadoon, Khan Zaib; Moghadas, Davood; Jadoon, Aurangzeb; Missimer, Thomas M.; Al-Mashharawi, Samir K.; McCabe, Matthew

2015-01-01

-Explorer) is used for subsurface characterization of soil salinity in a drip irrigation system via a joint inversion approach of multiconfiguration EMI measurements. EMI measurements were conducted across a farm where Acacia trees are irrigated with brackish water

Temperature Data Assimilation with Salinity Corrections: Validation for the NSIPP Ocean Data Assimilation System in the Tropical Pacific Ocean, 1993-1998

Science.gov (United States)

Troccoli, Alberto; Rienecker, Michele M.; Keppenne, Christian L.; Johnson, Gregory C.

2003-01-01

The NASA Seasonal-to-Interannual Prediction Project (NSIPP) has developed an Ocean data assimilation system to initialize the quasi-isopycnal ocean model used in our experimental coupled-model forecast system. Initial tests of the system have focused on the assimilation of temperature profiles in an optimal interpolation framework. It is now recognized that correction of temperature only often introduces spurious water masses. The resulting density distribution can be statically unstable and also have a detrimental impact on the velocity distribution. Several simple schemes have been developed to try to correct these deficiencies. Here the salinity field is corrected by using a scheme which assumes that the temperature-salinity relationship of the model background is preserved during the assimilation. The scheme was first introduced for a zlevel model by Troccoli and Haines (1999). A large set of subsurface observations of salinity and temperature is used to cross-validate two data assimilation experiments run for the 6-year period 1993-1998. In these two experiments only subsurface temperature observations are used, but in one case the salinity field is also updated whenever temperature observations are available.

Monitoring the Impact of Climate Change on Soil Salinity in Agricultural Areas Using Ground and Satellite Sensors

Science.gov (United States)

Corwin, D. L.; Scudiero, E.

2017-12-01

Changes in climatic patterns have had dramatic influence on agricultural areas worldwide, particularly in irrigated arid-zone agricultural areas subjected to recurring drought, such as California's San Joaquin Valley (SJV), or areas receiving above average rainfall for a decade or more, such as Minnesota's Red River Valley (RRV). Climate change has impacted water availability with an under or over abundance, which subsequently has impacted soil salinity levels in the root zone primarily from the upward movement of salts from shallow water tables. Inventorying and monitoring the impact of climate change on soil salinity is crucial to evaluate the extent of the problem, to recognize trends, and to formulate state-wide and field-scale irrigation, drainage, and crop management strategies that will sustain the agricultural productivity of the SJV and RRV. Over the past 3 decades, Corwin and colleagues at the U.S. Salinity Laboratory have developed proximal sensor (i.e., electrical resistivity and electromagnetic induction) and remote imagery (i.e., MODIS and Landsat 7) methodologies for assessing soil salinity at multiple scales: field (0.5 ha to 3 km2), landscape (3 to 10 km2), and regional (10 to 105 km2) scales. The purpose of this presentation is to provide an overview of these scale-dependent salinity assessment technologies. Case studies for SJV and RRV are presented to demonstrate at multiple scales the utility of these approaches in assessing soil salinity changes due to management-induced changes and to changes in climate patterns, and in providing site-specific irrigation management information for salinity control. Decision makers in state and federal agencies, irrigation and drainage district managers, soil and water resource managers, producers, agriculture consultants, extension specialists, and Natural Resource Conservation Service field staff are the beneficiaries of this information.

Surface and Subsurface Meltwater Ponding and Refreezing on the Bach Ice Shelf, Antarctic Peninsula

Science.gov (United States)

Willis, I.; Haggard, E.; Benedek, C. L.; MacAyeal, D. R.; Banwell, A. F.

2017-12-01

There is growing concern about the stability and fate of Antarctic ice shelves, as four major ice shelves on the Antarctic Peninsula have completely disintegrated since the 1950s. Their collapse has been linked to the southward movement of the -9 oC mean annual temperature isotherm. The proximal causes of ice shelf instability are not fully known, but an increase in surface melting leading to water ponding and ice flexure, fracture and calving has been implicated. Close to the recently collapsed Wilkins Ice Shelf, the Bach Ice Shelf (72°S 72°W) may be at risk from break up in the near future. Here, we document the changing surface hydrology of the Bach Ice Shelf between 2001 and 2017 using Landsat 7 & 8 imagery. Extensive surface water is identified across the Bach Ice Shelf and its tributary glaciers. Two types of drainage system are observed, drainage into firn via simple stream networks and drainage into the ocean via more complex networks. There are differences between the surface hydrology on the ice shelf and the tributary glaciers, as well as variations within and between summer seasons linked to surface air temperature fluctuations. We also document the changing subsurface hydrology of the ice shelf between 2014 and 2017 using Sentinel 1 A/B SAR imagery. Forty-five subsurface features are identified and analysed for their patterns and temporal evolution. Fourteen of the features show similar characteristics to previously-identified buried lakes and some occur in areas associated with surface lakes in previous years. The buried lakes show seasonal variability in area and surface backscatter, which varies with surface air temperature, and are consistent with the presence, enlargement and contraction of liquid water bodies. Buried lakes are an overlooked source of water loading on ice shelves, which may contribute to ice shelf flexure and potential fracture.

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

Science.gov (United States)

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.

Evolution of the electrical resistivity anisotropy during saline tracer tests: insights from geoelectrical milli-fluidic experiments

Science.gov (United States)

Jougnot, D.; Jimenez-Martinez, J.; Legendre, R.; Le Borgne, T.; Meheust, Y.; Linde, N.

2017-12-01

The use of time-lapse electrical resistivity tomography has been largely developed in environmental studies to remotely monitor water saturation and contaminant plumes migration. However, subsurface heterogeneities, and corresponding preferential transport paths, yield a potentially large anisotropy in the electrical properties of the subsurface. In order to study this effect, we have used a newly developed geoelectrical milli-fluidic experimental set-up with a flow cell that contains a 2D porous medium consisting of a single layer of cylindrical solid grains. We performed saline tracer tests under full and partial water saturations in that cell by jointly injecting air and aqueous solutions with different salinities. The flow cell is equipped with four electrodes to measure the bulk electrical resistivity at the cell's scale. The spatial distribution of the water/air phases and the saline solute concentration field in the water phase are captured simultaneously with a high-resolution camera by combining a fluorescent tracer with the saline solute. These data are used to compute the longitudinal and transverse effective electrical resistivity numerically from the measured spatial distributions of the fluid phases and the salinity field. This approach is validated as the computed longitudinal effective resistivities are in good agreement with the laboratory measurements. The anisotropy in electrical resistivity is then inferred from the computed longitudinal and transverse effective resistivities. We find that the spatial distribution of saline tracer, and potentially air phase, drive temporal changes in the effective resistivity through preferential paths or barriers for electrical current at the pore scale. The resulting heterogeneities in the solute concentrations lead to strong anisotropy of the effective bulk electrical resistivity, especially for partially saturated conditions. Therefore, considering the electrical resistivity as a tensor could improve our

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

Science.gov (United States)

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

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

Science.gov (United States)

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

Discontinuous drainage systems formed by highland precipitation and ground-water outflow in the Navua Valles and southwest Hadriacus Mons regions, Mars

Science.gov (United States)

Hargitai, H. I.; Gulick, V. C.; Glines, N. H.

2017-09-01

The Navua Valles are systems of paleodrainages located north of Dao Vallis, which empty into Hellas Planitia, the largest impact basin on Mars. In this study, we mapped and characterized the Navua Valles Region's individual drainage systems, including drainages along the southwestern flank of Hadriacus Mons, and one valley network from the same source as Navua Valles but flowing in the opposite direction. The major drainage systems share morphological characteristics common to both outflow channels and valley networks. The slopes in this region are dissected by two major Navua drainage systems (here Navua A* and B*) and several shorter, sub-parallel valleys formed on the highest gradient (approximately 20 m/km [1.15°]) slopes, at the lowest part of Hellas Basin's rim. The two major drainage systems originate in the highlands, and empty into the basin. Our mapping suggests that water in Navua Valles reached the basin floor in a complicated descent and included several episodes of surface ponding, surface runoff, infiltration, subsurface flow and subsequent outflow. The most prominent channel system, Navua A, forms a repetitive sequence of deep incision into bedrock, followed by a transition into broad channels in erodible materials, and then into unconfined deposits. This successive erosion-transport-deposition sequence continues to repeat along the valley's entire length forming a discontinuous pattern that is consistent with classical fluvial process models. The channels cut into volcanic plains likely emplaced from the formation of Tyrrhenus and Hadriacus Montes. The dendritic source valleys of Navua A originate from the rim of a highland crater while the rest of this subsystem consists of a single, discontinuous channel which is consistent with a single water source zone that likely supplied water for all channels downslope. These drainages may have formed as discontinuous channels, revealing the potential existence of subsurface drainage pathways located

Salinity and cationic nature of irrigation water on castor bean cultivation

Directory of Open Access Journals (Sweden)

Geovani S. de Lima

Full Text Available ABSTRACT This study aimed to evaluate the water relations, cell damage percentage and growth of the castor bean cv. ‘BRS Energia’ as a function of salinity and cationic nature of the water used in irrigation. The experiment was conducted in drainage lysimeters under greenhouse conditions in eutrophic Grey Argisol of sandy loam texture. Six combinations of water salinity and cations were studied (S1 - Control; S2 - Na+, S3 - Ca2+, S4 - Na+ + Ca2+; S5 - K+ and S6 - Na+ + Ca2+ + Mg2+, in a randomized block design with four replicates. In the control (S1, plants were irrigated with 0.6 dS m-1 water, whereas the other treatments received 4.5 dS m-1 water, obtained by adding different salts, all in the chloride form. Higher relative water content in the leaf blade of plants irrigated with K+-salinized water associated with leaf succulence are indicative of tolerance of the castor bean cv. ‘BRS Energia’ to salinity. Saline stress negatively affected castor bean growth, regardless of cationic nature of water. Among the ions studied, ‘BRS Energia’ castor bean was more sensitive to the presence of sodium in the irrigation water, in terms of both water relations and leaf succulence.

Two fixed ratio dilutions for soil salinity monitoring in hypersaline wetlands.

Directory of Open Access Journals (Sweden)

Juan Herrero

Full Text Available Highly soluble salts are undesirable in agriculture because they reduce yields or the quality of most cash crops and can leak to surface or sub-surface waters. In some cases salinity can be associated with unique history, rarity, or special habitats protected by environmental laws. Yet in considering the measurement of soil salinity for long-term monitoring purposes, adequate methods are required. Both saturated paste extracts, intended for agriculture, and direct surface and/or porewater salinity measurement, used in inundated wetlands, are unsuited for hypersaline wetlands that often are only occasionally inundated. For these cases, we propose the use of 1:5 soil/water (weight/weight extracts as the standard for expressing the electrical conductivity (EC of such soils and for further salt determinations. We also propose checking for ion-pairing with a 1:10 or more diluted extract in hypersaline soils. As an illustration, we apply the two-dilutions approach to a set of 359 soil samples from saline wetlands ranging in ECe from 2.3 dS m(-1 to 183.0 dS m(-1. This easy procedure will be useful in survey campaigns and in the monitoring of soil salt content.

Two fixed ratio dilutions for soil salinity monitoring in hypersaline wetlands.

Science.gov (United States)

Herrero, Juan; Weindorf, David C; Castañeda, Carmen

2015-01-01

Highly soluble salts are undesirable in agriculture because they reduce yields or the quality of most cash crops and can leak to surface or sub-surface waters. In some cases salinity can be associated with unique history, rarity, or special habitats protected by environmental laws. Yet in considering the measurement of soil salinity for long-term monitoring purposes, adequate methods are required. Both saturated paste extracts, intended for agriculture, and direct surface and/or porewater salinity measurement, used in inundated wetlands, are unsuited for hypersaline wetlands that often are only occasionally inundated. For these cases, we propose the use of 1:5 soil/water (weight/weight) extracts as the standard for expressing the electrical conductivity (EC) of such soils and for further salt determinations. We also propose checking for ion-pairing with a 1:10 or more diluted extract in hypersaline soils. As an illustration, we apply the two-dilutions approach to a set of 359 soil samples from saline wetlands ranging in ECe from 2.3 dS m(-1) to 183.0 dS m(-1). This easy procedure will be useful in survey campaigns and in the monitoring of soil salt content.

[Vacuum sealing drainage for infection wound in earthquake].

Science.gov (United States)

Liao, Dengbin; Ning, Ning; Liu, Xiaoyan; Gan, Chunlan

2009-10-01

To investigate the effect of vacuum sealing drainage (VSD) technology on prevention and treatment of infection wound and to repair the infectious fracture wound in earthquake. Twenty-two patients with limb fractures and open infection wound received VSD from May 12, 2008 to June 19, 2008 in West China Hospital of Sichuan University. Before the VSD, we debrided all wounds and gave effective systemic antibiotics. A -18 ~ -14 kPa pressure was exerted to the wound, and the VSD was used for 8-10 days. We took a germiculture regularly. The capacity, color, and nature of negative pressure drainage, the regression of limb swelling, and systemic inflammatory responses were observed. There was no active bleeding wound or transparent film off in all patients. Three patients had drainage clogging, and were kept flowing freely using the sterile saline pipe to remove the blockage of necrotic tissues. During the VSD, granulation tissues grew well in the 13 patients with bone exposure of the wounded. Two patients whose symptom of inflammatory was not obviously eased had another debridement to completely remove the necrosis, and the symptom was relieved. After 3-5 days of VSD, swelling and fever in the other 20 patients significantly subsided. VSD can alleviate the wound inflammation, facilitate the growth of the fresh granulation tissue from the surrounding to the center, and reduce the flap transfer area for the Stage II coverage of the exposed bone.

Toward Monitoring Surface and Subsurface Lakes on the Greenland Ice Sheet Using Sentinel-1 SAR and Landsat-8 OLI Imagery

Directory of Open Access Journals (Sweden)

Katie E. Miles

2017-07-01

Full Text Available Supraglacial lakes are an important component of the Greenland Ice Sheet's mass balance and hydrology, with their drainage affecting ice dynamics. This study uses imagery from the recently launched Sentinel-1A Synthetic Aperture Radar (SAR satellite to investigate supraglacial lakes in West Greenland. A semi-automated algorithm is developed to detect surface lakes from Sentinel-1 images during the 2015 summer. A combined Landsat-8 and Sentinel-1 dataset, which has a comparable temporal resolution to MODIS (3 days vs. daily but a higher spatial resolution (25–40 vs. 250–500 m, is then used together with a fully automated lake drainage detection algorithm. Rapid (<4 days and slow (>4 days drainages are investigated for both small (<0.125 km2, the minimum size detectable by MODIS and large (≥0.125 km2 lakes through the summer. Drainage events of small lakes occur at lower elevations (mean 159 m, and slightly earlier (mean 4.5 days in the melt season than those of large lakes. The analysis is extended manually into the early winter to calculate the dates and elevations of lake freeze-through more precisely than is possible with optical imagery (mean 30 August; 1,270 m mean elevation. Finally, the Sentinel-1 imagery is used to detect subsurface lakes and, for the first time, their dates of appearance and freeze-through (mean 9 August and 7 October, respectively. These subsurface lakes occur at higher elevations than the surface lakes detected in this study (mean 1,593 and 1,185 m, respectively. Sentinel-1 imagery therefore provides great potential for tracking melting, water movement and freezing within both the firn zone and ablation area of the Greenland Ice Sheet.

Transboundary geophysical mapping of geological elements and salinity distribution critical for the assessment of future sea water intrusion in response to sea level rise

DEFF Research Database (Denmark)

Joergensen, F.; Scheer, W.; Thomsen, S.

2012-01-01

Geophysical techniques are increasingly being used as tools for characterising the subsurface, and they are generally required to develop subsurface models that properly delineate the distribution of aquifers and aquitards, salt/freshwater interfaces, and geological structures that affect......, and sand aquifers are all examples of geological structures mapped by the geophysical data that control groundwater flow and to some extent hydrochemistry. Additionally, the data provide an excellent picture of the salinity distribution in the area and thus provide important information on the salt...... revealed. The mapped salinity distribution indicates preferential flow paths through and along specific geological structures within the area. The effects of a future sea level rise on the groundwater system and groundwater chemistry are discussed with special emphasis on the importance of knowing...

Review of Constructed Subsurface Flow vs. Surface Flow Wetlands

International Nuclear Information System (INIS)

HALVERSON, NANCY

2004-01-01

The purpose of this document is to use existing documentation to review the effectiveness of subsurface flow and surface flow constructed wetlands in treating wastewater and to demonstrate the viability of treating effluent from Savannah River Site outfalls H-02 and H-04 with a subsurface flow constructed wetland to lower copper, lead and zinc concentrations to within National Pollutant Discharge Elimination System (NPDES) Permit limits. Constructed treatment wetlands are engineered systems that have been designed and constructed to use the natural functions of wetlands for wastewater treatment. Constructed wetlands have significantly lower total lifetime costs and often lower capital costs than conventional treatment systems. The two main types of constructed wetlands are surface flow and subsurface flow. In surface flow constructed wetlands, water flows above ground. Subsurface flow constructed wetlands are designed to keep the water level below the top of the rock or gravel media, thus minimizing human and ecological exposure. Subsurface flow wetlands demonstrate higher rates of contaminant removal per unit of land than surface flow (free water surface) wetlands, therefore subsurface flow wetlands can be smaller while achieving the same level of contaminant removal. Wetlands remove metals using a variety of processes including filtration of solids, sorption onto organic matter, oxidation and hydrolysis, formation of carbonates, formation of insoluble sulfides, binding to iron and manganese oxides, reduction to immobile forms by bacterial activity, and uptake by plants and bacteria. Metal removal rates in both subsurface flow and surface flow wetlands can be high, but can vary greatly depending upon the influent concentrations and the mass loading rate. Removal rates of greater than 90 per cent for copper, lead and zinc have been demonstrated in operating surface flow and subsurface flow wetlands. The constituents that exceed NPDES limits at outfalls H-02 a nd H

Mapping and monitoring nuclear waste repositories with subsurface electrical resistivity arrays

International Nuclear Information System (INIS)

Asch, T.; Morrison, H.F.

1987-01-01

The siting and future integrity of nuclear waste repositories is critically dependent on the local ground water regime. Electrical methods seem particularly promising in mapping and monitoring this regime since the electrical conductivity of rocks depends almost entirely on the fluid saturation, salinity and distribution. The most important recent developments in resistivity include the use of numerical modeling and resistivity mapping using subsurface electrodes. The latter yields far greater accuracy and resolution than can be obtained with surface arrays. To illustrate the power of subsurface-surface arrays the authors studied an idealized two dimensional model of a nuclear repository. Since they are interested in emphasizing the anomaly caused by the repository, or subsequent changes over time in its vicinity, the authors discovered that it is very useful to express the apparent resistivity results as percentage differences from either the background (for surface arrays) or from the apparent resistivities observed at a particular depth of the current source (for subsurface arrays). Percent differencing with respect to data at the repository depth dramatically reduce near-surface and topographic effects that usually confound quantitative interpretation of surface surveys. Thus, dc resistivity appears to have great potential for nuclear waste repository mapping and monitoring

Simulating Salt Movement using a Coupled Salinity Transport Model in a Variably Saturated Agricultural Groundwater System

Science.gov (United States)

Tavakoli Kivi, S.; Bailey, R. T.; Gates, T. K.

2017-12-01

Salinization is one of the major concerns in irrigated agricultural fields. Increasing salinity concentrations are due principally to a high water table that results from excessive irrigation, canal seepage, and a lack of efficient drainage systems, and lead to decreasing crop yield. High groundwater salinity loading to nearby river systems also impacts downstream areas, with saline river water diverted for application on irrigated fields. To assess the different strategies for salt remediation, we present a reactive transport model (UZF-RT3D) coupled with a salinity equilibrium chemistry module for simulating the fate and transport of salt ions in a variably-saturated agricultural groundwater system. The developed model accounts not for advection, dispersion, nitrogen and sulfur cycling, oxidation-reduction, sorption, complexation, ion exchange, and precipitation/dissolution of salt minerals. The model is applied to a 500 km2 region within the Lower Arkansas River Valley (LARV) in southeastern Colorado, an area acutely affected by salinization in the past few decades. The model is tested against salt ion concentrations in the saturated zone, total dissolved solid concentrations in the unsaturated zone, and salt groundwater loading to the Arkansas River. The model now can be used to investigate salinity remediation strategies.

Nitrogen and phosphorus changes and optimal drainage time of flooded paddy field based on environmental factors

Directory of Open Access Journals (Sweden)

Meng-hua Xiao

2013-04-01

Full Text Available While many controlled irrigation and drainage techniques have been adopted in China, the environmental effects of these techniques require further investigation. This study was conducted to examine the changes of nitrogen and phosphorus of a flooded paddy water system after fertilizer application and at each growth stage so as to obtain the optimal drainage time at each growth stage. Four treatments with different water level management methods at each growth stage were conducted under the condition of ten-day continuous flooding. Results show that the ammonia nitrogen (NH+4-N concentration reached the peak value once the fertilizer was applied, and then decreased to a relatively low level seven to ten days later, and that the nitrate nitrogen (NO-3-N concentration gradually rose to its peak value, which appeared later in subsurface water than in surface water. Continuous flooding could effectively reduce the concentrations of NH+4-N, NO-3-N , and total phosphorus (TP in surface water. However, the paddy water disturbance, in the process of soil surface adsorption and nitrification, caused NH+4-N to be released and increased the concentrations of NH+4-N and NO-3-N in surface water. A multi-objective controlled drainage model based on environmental factors was established in order to obtain the optimal drainage time at each growth stage and better guide the drainage practices of farmers. The optimal times for surface drainage are the fourth, sixth, fifth, and sixth days after flooding at the tillering, jointing-booting, heading-flowering, and milking stages, respectively.

Comparison between autologous blood transfusion drainage and closed-suction drainage/no drainage in total knee arthroplasty: a meta-analysis.

Science.gov (United States)

Hong, Kun-Hao; Pan, Jian-Ke; Yang, Wei-Yi; Luo, Ming-Hui; Xu, Shu-Chai; Liu, Jun

2016-08-01

Autologous blood transfusion (ABT) drainage system is a new unwashed salvaged blood retransfusion system for total knee replacement (TKA). However, whether to use ABT drainage, closed-suction (CS) drainage or no drainage in TKA surgery remains controversial. This is the first meta-analysis to assess the clinical efficiency, safety and potential advantages regarding the use of ABT drains compared with closed-suction/no drainage. PubMed, Embase, and the Cochrane Library were comprehensively searched in March 2015. Fifteen randomized controlled trials (RCTs) were identified and pooled for statistical analysis. The primary outcome evaluated was homologous blood transfusion rate. The secondary outcomes were post-operative haemoglobin on days 3-5, length of hospital stay and wound infections after TKA surgery. The pooled data included 1,721 patients and showed that patients in the ABT drainage group might benefit from lower blood transfusion rates (16.59 % and 37.47 %, OR: 0.28 [0.14, 0.55]; 13.05 % and 16.91 %, OR: 0.73 [0.47,1.13], respectively). Autologous blood transfusion drainage and closed-suction drainage/no drainage have similar clinical efficacy and safety with regard to post-operative haemoglobin on days 3-5, length of hospital stay and wound infections. Autologous blood transfusion drainage offers a safe and efficient alternative to CS/no drainage with a lower blood transfusion rate. Future large-volume high-quality RCTs with extensive follow-up will affirm and update this system review.

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

Science.gov (United States)

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.

Salinization of aquifers at the regional scale by marine transgression: Time scales and processes

Science.gov (United States)

Armandine Les Landes, A.; Davy, P.; Aquilina, L.

2014-12-01

Saline fluids with moderate concentrations have been sampled and reported in the Armorican basement at the regional scale (northwestern France). The horizontal and vertical distributions of high chloride concentrations (60-1400mg/L) at the regional scale support the marine origin and provide constraints on the age of these saline fluids. The current distribution of fresh and "saline" groundwater at depth is the result mostly of processes occurring at geological timescales - seawater intrusion processes followed by fresh groundwater flushing -, and only slightly of recent anthropogenic activities. In this study, we focus on seawater intrusion mechanisms in continental aquifers. We argue that one of the most efficient processes in macrotidal environments is the gravity-driven downconing instability below coastal salinized rivers. 2-D numerical experiments have been used to quantify this process according to four main parameter types: (1) the groundwater system permeability, (2) the salinity degree of the river, (3) the river width and slope, and (4) the tidal amplitude. A general expression of the salinity inflow rates have been derived, which has been used to estimate groundwater salinization rates in Brittany, given the geomorphological and environmental characteristics (drainage basin area, river widths and slopes, tidal range, aquifer permeability). We found that downconing below coastal rivers entail very high saline rates, indicating that this process play a major role in the salinization of regional aquifers. This is also likely to be an issue in the context of climate change, where sea-level rise is expected.

Sediment and Nutrient Contributions from Subsurface Drains and Point Sources to an Agricultural Watershed

Directory of Open Access Journals (Sweden)

Bonnie Ball Coelho

2010-03-01

Full Text Available Excess sediment and nutrients in surface waters can threaten aquatic life. To determine the relative importance of subsurface drainage as a pathway for movement of sediment and nutrients to surface waters, loading from various tile systems was compared to that from sewage treatment plants (STP within the same watershed. Movement through tiles comprised 1 to 8% of estimated total (overland plus tile annual sediment loading from the respective areas drained by the tile. Load during the growing season from five closed drain- age systems without surface inlets averaged 5 kg sediment/ha, 0.005 kg dissolved reactive P (DRP/ha, 0.003 kg NH4-N/ha, and 3.8 kg NO3-N/ha; and from two open drainage systems with surface inlets averaged 14 kg sediment/ha, 0.03 kg DRP/ha, 0.04 kg NH4-N/ha, and 3.1 kg NO3-N/ha. The eight STP contributed about 44 530 kg suspended sediments, 3380 kg total P, 1340 kg NH4-N, and 116 900 kg NO3-N to the watershed annually. Drainage systems added less NH4-N and P, but more NO3-N and suspended solids to surface waters than STP. Tile drainage pathways for NO3-N, STP in the case of P, and overland pathways for sediment are indicated as targets to control loading in artificially drained agricultural watersheds.

Peritoneal Drainage Versus Pleural Drainage After Pediatric Cardiac Surgery.

Science.gov (United States)

Gowda, Keshava Murty Narayana; Zidan, Marwan; Walters, Henry L; Delius, Ralph E; Mastropietro, Christopher W

2014-07-01

We aimed to determine whether infants undergoing cardiac surgery would more efficiently attain negative fluid balance postoperatively with passive peritoneal drainage as compared to traditional pleural drainage. A prospective, randomized study including children undergoing repair of tetralogy of Fallot (TOF) or atrioventricular septal defect (AVSD) was completed between September 2011 and June 2013. Patients were randomized to intraoperative placement of peritoneal catheter or right pleural tube in addition to the requisite mediastinal tube. The primary outcome measure was fluid balance at 48 hours postoperatively. Variables were compared using t tests or Fisher exact tests as appropriate. A total of 24 patients were enrolled (14 TOF and 10 AVSD), with 12 patients in each study group. Mean fluid balance at 48 hours was not significantly different between study groups, -41 ± 53 mL/kg in patients with periteonal drainage and -9 ± 40 mL/kg in patients with pleural drainage (P = .10). At 72 hours however, postoperative fluid balance was significantly more negative with peritoneal drainage, -52.4 ± 71.6 versus +2.0 ± 50.6 (P = .04). On subset analysis, fluid balance at 48 hours in patients with AVSD was more negative with peritoneal drainage as compared to pleural, -82 ± 51 versus -1 ± 38 mL/kg, respectively (P = .02). Fluid balance at 48 hours in patients with TOF was not significantly different between study groups. Passive peritoneal drainage may more effectively facilitate negative fluid balance when compared to pleural drainage after pediatric cardiac surgery, although this benefit is not likely universal but rather dependent on the patient's underlying physiology. © The Author(s) 2014.

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

Science.gov (United States)

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.

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

Science.gov (United States)

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.

Mine drainage treatment

OpenAIRE

Golomeova, Mirjana; Zendelska, Afrodita; Krstev, Boris; Golomeov, Blagoj; Krstev, Aleksandar

2012-01-01

Water flowing from underground and surface mines and contains high concentrations of dissolved metals is called mine drainage. Mine drainage can be categorized into several basic types by their alkalinity or acidity. Sulfide rich and carbonate poor materials are expected to produce acidic drainage, and alkaline rich materials, even with significant sulfide concentrations, often produce net alkaline water. Mine drainages are dangerous because pollutants may decompose in the environment. In...

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

Science.gov (United States)

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.

Iron removal from acid mine drainage by wetlands

Energy Technology Data Exchange (ETDEWEB)

Sexstone, A.J.; Skousen, J.G.; Calabrese, J.; Bhumbla, D.K.; Cliff, J.; Sencindiver, J.C.; Bissonnette, G.K.

1999-07-01

Neutralization of acid mine drainage (AMD) in man-made cattail (Typha) wetlands was investigated over a four-year period utilizing experimental models constructed in a greenhouse. A naturally occurring AMD (430 mg/L Fe, 5 mg/L Mn, 2,900 mg/L sulfate, pH 2.75) was collected in the field and added to the greenhouse wetlands at 60.5 L/day. Monthly water samples from four depths (10, 20, 30, and 40 cm) were obtained from the influent, midpoint, and effluent locations of the wetland. During the first year of AMD treatment, near neutral pH (6.5) and anoxic conditions ({minus}300 mV) were observed in subsurface sediments of wetlands. The wetlands retained an estimated 65% of the total applied iron in the first year, primarily in the exchangeable, organically bound, and oxide form. During later years, 20 to 30% of the influent iron was retained predominantly as precipitated oxides. Iron sulfides resulting form sulfate reduction accounted for less than 5% of the iron retained, and were recovered primarily as monosulfides during the first year and as disulfides in the fourth year. Improvement in effluent pH was primarily attributed to limestone dissolution in the anaerobic subsurface sediments, which decreased with time. Constructed wetlands exhibit finite lives for effective AMD treatment and provisions should be made for their periodic rejuvenation or replacement.

Grazing as an alternative for utilization of saline-sodic soils in the San Joaquin Valley: Selenium accretion and performance of beef heifers

Energy Technology Data Exchange (ETDEWEB)

Juchem, Sergio O., E-mail: sdjuchem@gmail.com [Department of Animal Science, University of California, Davis, CA 95616 (United States); Department of Plant Science, California State University, Fresno, CA 93740-8033 (United States); Benes, Sharon E. [Department of Plant Science, California State University, Fresno, CA 93740-8033 (United States); Robinson, P.H. [Department of Animal Science, University of California, Davis, CA 95616 (United States); Grattan, Stephen R. [Department of Land and Water Resources, University of California, Davis, CA 95616 (United States); Vasquez, Pablo [Department of Plant Science, California State University, Fresno, CA 93740-8033 (United States); Chilibroste, Pablo [Instituto Nacional de Investigacion Agropecuaria, Paysandu (Uruguay); Brito, Martin [Department of Plant Science, California State University, Fresno, CA 93740-8033 (United States)

2012-03-01

Two experiments were conducted to evaluate Se accumulation and health of non-pregnant, non-breeding beef cattle grazing on forages with a high Se content due to irrigation with saline drainage water. Heifers grazed experimental pastures of 'Jose' tall wheatgrass (TWG; Thinopyrum ponticum var. 'Jose') and creeping wildrye (CWR; Leymus triticoides var. 'Rio') for190 days in Experiment 1 (2007) and for 165 days in Experiment 2 (2008). In experiment 1, mean Se concentrations were similar in TWG and CWR herbage (4.0 versus 3.7 {+-} 0.26 mg/kg dry weight; p = 0.34) as was crude protein (113 versus 114 {+-} 7.9 g/kg dry weight; p = 0.94). Concentrations of Se in blood increased by 300% during the grazing period, and were similar for heifers grazing the TWG or CWR pastures (0.94 versus 0.87 {+-} 0.03 mg/kg; p = 0.89). Heifers grazing on TWG gained more body weight than did heifers grazing on CWR (0.59 versus 0.27 {+-} 0.07 kg/days; p < 0.01). In experiment 2, concentration of Se (4.0 versus 2.8 mg/kg {+-} 0.19 mg/kg dry weight; p < 0.01) and crude protein (79 versus 90 {+-} 5.6 g/kg dry weight; p < 0.01) differed, for TWG and CWR, respectively. Within 20 days, Se concentrations in blood had increased by 300% and by nearly 200% in heifers grazing on TWG or CWR. All data cited are least square means {+-} standard error of the mean. Data from our two grazing seasons are consistent in demonstrating the safety of grazing beef cattle for a period of up to 6 months on TWG and CWR forages having high levels of Se due to irrigation with saline drainage water. This suggests that forage production using saline drainage water is a viable alternative for saline soils with limited potential for producing high value, salt-sensitive, crops. - Highlights: Black-Right-Pointing-Pointer Forages irrigated with saline drainage water may contain high levels of selenium. Black-Right-Pointing-Pointer High concentration of selenium in forages can be toxic to grazing

Grazing as an alternative for utilization of saline-sodic soils in the San Joaquin Valley: Selenium accretion and performance of beef heifers

International Nuclear Information System (INIS)

Juchem, Sérgio O.; Benes, Sharon E.; Robinson, P.H.; Grattan, Stephen R.; Vasquez, Pablo; Chilibroste, Pablo; Brito, Martin

2012-01-01

Two experiments were conducted to evaluate Se accumulation and health of non-pregnant, non-breeding beef cattle grazing on forages with a high Se content due to irrigation with saline drainage water. Heifers grazed experimental pastures of “Jose” tall wheatgrass (TWG; Thinopyrum ponticum var. “Jose”) and creeping wildrye (CWR; Leymus triticoides var. “Rio”) for190 days in Experiment 1 (2007) and for 165 days in Experiment 2 (2008). In experiment 1, mean Se concentrations were similar in TWG and CWR herbage (4.0 versus 3.7 ± 0.26 mg/kg dry weight; p = 0.34) as was crude protein (113 versus 114 ± 7.9 g/kg dry weight; p = 0.94). Concentrations of Se in blood increased by 300% during the grazing period, and were similar for heifers grazing the TWG or CWR pastures (0.94 versus 0.87 ± 0.03 mg/kg; p = 0.89). Heifers grazing on TWG gained more body weight than did heifers grazing on CWR (0.59 versus 0.27 ± 0.07 kg/days; p < 0.01). In experiment 2, concentration of Se (4.0 versus 2.8 mg/kg ± 0.19 mg/kg dry weight; p < 0.01) and crude protein (79 versus 90 ± 5.6 g/kg dry weight; p < 0.01) differed, for TWG and CWR, respectively. Within 20 days, Se concentrations in blood had increased by 300% and by nearly 200% in heifers grazing on TWG or CWR. All data cited are least square means ± standard error of the mean. Data from our two grazing seasons are consistent in demonstrating the safety of grazing beef cattle for a period of up to 6 months on TWG and CWR forages having high levels of Se due to irrigation with saline drainage water. This suggests that forage production using saline drainage water is a viable alternative for saline soils with limited potential for producing high value, salt-sensitive, crops. - Highlights: ► Forages irrigated with saline drainage water may contain high levels of selenium. ► High concentration of selenium in forages can be toxic to grazing cattle. ► Cattle accumulated high levels of selenium in blood, liver and muscle

Sorbents for phosphate removal from agricultural drainage water

DEFF Research Database (Denmark)

Lyngsie, Gry

Subsurface transport of phosphate (P) from fertilized agricultural fields to freshwaters may lead to eutrophication and reduced biodiversity in inland waters. Mitigation of eutrophic waters is difficult and costly. Reduction of P export to surface waters using filters installed in agricultural...... drains comprising P sorbing materials (PSM) may be a more efficient and cost-effective way to improve water quality. Several materials have been proposed as PSMs for use for cleaning agricultural drainage water. The objective of the present study was to provide data on sorption behavior among a variety...... of PSMs in order to select a material that can quickly remove P from runoff water at both base and peak flow. This was done by screening 15 “local” PSMs’ for their ability to sorb and retain low orthophosphate concentrations (0-161 µM) at short equilibration time (

Temporal geochemical variations in above- and below-drainage coal mine discharge

Science.gov (United States)

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 water quality presented in this paper can help prioritize CMD remediation and facilitate selection and design of the most appropriate treatment systems.

Global 30m Height Above the Nearest Drainage

Science.gov (United States)

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

Cholangitis following percutaneous biliary drainage

International Nuclear Information System (INIS)

Audisio, R.A.; Bozzetti, F.; Cozzi, G.; Severini, A.; Belloni, M.; Friggerio, L.F.

1989-01-01

The binomial PTBD-cholangitis often stands under different and sometimes even opposite relations. Among its indications the procedure lists, the treatment of cholangitis which, on the other hand, may be itself a complication of biliary drainage. The present work proposes a critical review of cholangitis-PTBD correlations, from an ordinary clinical-radiological point of view. Different pathogenetic hypothesis of cholangitis (inflammation, cholestasis, surgical manipulation) are discussed together with risk factors (impaired macrophagic-phagocytic system, immunosuppresion, wide neoplastic liver involvement, multiple intrahepatic ductal obstructions, chronic liver diseases, aged patients, etc.). The authors also report about prevention and treatment of septic complications which must be carried out following technical and therapeutic strategies, such as chemoprophylaxis and focused antibiotic therapy according to coltural samples, slow injection of small amounts of contrast medium, peripheral branches approach, gentle handling of catheters and guidewires, flushing with saline solutions and brushing of the catheter itself, and finally use of large gauge catheters in the presence of bile sludge

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

Science.gov (United States)

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.

Surgical uterine drainage and lavage as treatment for canine pyometra : clinical communication

Directory of Open Access Journals (Sweden)

K.G.M. De Cramer

2010-05-01

Full Text Available Pyometra is a common post-oestral syndrome in bitches. Classical treatment consists of either ovariohystorectomy or medical intervention. Surgical uterine drainage and lavage via direct trans-cervical catheterisation using a 5% povidone-iodine in saline solution was performed successfully in 8 bitches with pyometra. All bitches conceived and whelped without complications subsequent to this treatment. It is concluded that this method offers an effective alternative treatment for canine pyometra with shorter recovery times as well as good clinical recovery and pregnancy rates in bitches destined for further breeding.

Physiological and biochemical responses to the exogenous application of proline of tomato plants irrigated with saline water

Directory of Open Access Journals (Sweden)

B. Kahlaoui

2018-01-01

Full Text Available In scope of crop salinity tolerance, an experiment was carried out in a field using saline water (6.57 dS m−1 and subsurface drip irrigation (SDI on two tomato cultivars (Solanum lycopersicum, cv. Rio Grande and Heinz-2274 in a salty clay soil. Exogenous application of proline was done by foliar spray at two concentrations: 10 and 20 mg L−1, with a control (saline water without proline, during the flowering stage. Significant higher increases in proline and total soluble protein contents, glutamine synthetase (GS, EC6.3.1.2 activities and decreases in proline oxidase (l-proline: O2 Oxidoreductase, EC1.4.3.1 activities were detected in both tomato cultivars when irrigated with saline water (6.57 dS m−1 and exogenously applied by the lower concentration of proline. Taking in consideration the obtained results, it was concluded that the foliar spray of low concentration of proline can increase the tolerance of both cultivars of tomato to salinity under field conditions.

WATER DRAINAGE MODEL

International Nuclear Information System (INIS)

Case, J.B.

2000-01-01

The drainage of water from the emplacement drift is essential for the performance of the EBS. The unsaturated flow properties of the surrounding rock matrix and fractures determine how well the water will be naturally drained. To enhance natural drainage, it may be necessary to introduce engineered drainage features (e.g. drilled holes in the drifts), that will ensure communication of the flow into the fracture system. The purpose of the Water Drainage Model is to quantify and evaluate the capability of the drift to remove water naturally, using the selected conceptual repository design as a basis (CRWMS M andO, 1999d). The analysis will provide input to the Water Distribution and Removal Model of the EBS. The model is intended to be used to provide postclosure analysis of temperatures and drainage from the EBS. It has been determined that drainage from the EBS is a factor important to the postclosure safety case

Shallow rainwater lenses in deltaic areas with saline seepage

Directory of Open Access Journals (Sweden)

P. G. B. de Louw

2011-12-01

Full Text Available In deltaic areas with saline seepage, freshwater availability is often limited to shallow rainwater lenses lying on top of saline groundwater. Here we describe the characteristics and spatial variability of such lenses in areas with saline seepage and the mechanisms that control their occurrence and size. Our findings are based on different types of field measurements and detailed numerical groundwater models applied in the south-western delta of the Netherlands. By combining the applied techniques we could extrapolate measurements at point scale (groundwater sampling, temperature and electrical soil conductivity (TEC-probe measurements, electrical cone penetration tests (ECPT to field scale (continuous vertical electrical soundings (CVES, electromagnetic survey with EM31, and even to regional scale using helicopter-borne electromagnetic measurements (HEM. The measurements show a gradual mixing zone between infiltrating fresh rainwater and upward flowing saline groundwater. The mixing zone is best characterized by the depth of the centre of the mixing zone D_mix, where the salinity is half that of seepage water, and the bottom of the mixing zone B_mix, with a salinity equal to that of the seepage water (Cl-conc. 10 to 16 g l⁻¹. D_mix is found at very shallow depth in the confining top layer, on average at 1.7 m below ground level (b.g.l., while B_mix lies about 2.5 m b.g.l. The model results show that the constantly alternating upward and downward flow at low velocities in the confining layer is the main mechanism of mixing between rainwater and saline seepage and determines the position and extent of the mixing zone (D_mix and B_mix. Recharge, seepage flux, and drainage depth are the controlling factors.

Microbiological monitoring of carbon dioxide storage in a subsurface saline aquifer in Ketzin/Germany within the scope of CO2SINK

Science.gov (United States)

Wandrey, M.; Morozova, D.; Zemke, K.; Lerm, S.; Scherf, A.-K.; Vieth, A.; Würdemann, H.; Co2SINK Group

2009-04-01

Within the scope of the EU project CO2SINK (www.co2sink.org) a research facility in Ketzin (Germany, west of Berlin) is operated to store CO2 in a saline subsurface aquifer (Würdemann et al., EGU General Assembly 2009). In order to examine the influence of CO2 storage on the environment a comprehensive monitoring program is applied at this site including molecular and microbiological investigations. With the injection of CO2 into the geological formation chemical and physical reservoir characteristics are changed. This may influence the composition and activities of the deep biosphere at the storage horizon. Mineral precipitation, dissolution and corrosion of reservoir casing may be consequences, influencing permeability and long-term stability of the reservoir. The objective of the microbial monitoring program is the characterisation of the microbial community (biocenosis) in fluid samples, as well as in samples from reservoir and cap rock before and during CO2storage using molecular biological methods. 16S rRNA taxonomic studies, Fluorescence in situ hybridisation (FISH), and RealTime PCR are used to examine the composition of the biocenosis. First results of fluid sampling revealed that the microbial community of the saline aquifer is dominated by haloalkaliphilic fermentative bacteria and extremophilic organisms, coinciding with reduced conditions, high salinity and pressure. RealTime RT-PCR of selected genes and the creation and analysis of cDNA libraries will allow the prediction of microbial metabolic activities. In addition, the analysis of organic and inorganic components of the samples will add to the knowledge of possible metabolic shifts during CO2 storage. In order to simulate the storage conditions in situ, long term laboratory experiments in high pressure incubators have been set up using original rock cores from Ketzin. Since DNA and RNA analysis techniques are very sensitive, contamination entries from the adjacent environment have to be excluded

Circulation of the thermocline salinity maximum waters off the Northern Brazil as inferred from in situ measurements and numerical results

Energy Technology Data Exchange (ETDEWEB)

Silva, A.C. [Universidade Federal do Ceara, Fortaleza, CE (Brazil). Inst. de Ciencias do Mar; Bourles, B. [Inst. de Recherche pour le Developpement, Cotonou (Benin); Araujo, M. [UFPE, Recife, PE (Brazil). Lab. de Oceanografia Fisica Estuarina e Costeira

2009-07-01

High resolution hydrographic observations of temperature and salinity are used to analyse the subsurface circulation along the coast of North Brazil, off the Amazon mouth, between 2 S and 6 N. Observations are presented from four cruises carried out in different periods of the year (March-May 1995, May-June 1999, July-August 2001 and October-November 1997). Numerical model outputs complement the results of the shipboard measurements, and are used to complete the descriptions of mesoscale circulation. The Salinity Maximum Waters are here analyzed, principally in order to describe the penetration of waters originating in the Southern Hemisphere toward the Northern Hemisphere through the North Brazil Current (NBC)/North Brazil Undercurrent (NBUC). Our results show that, if the Equatorial Undercurrent (EUC) is fed by Northern Atlantic Waters, this contribution may only occur in the ocean interior, east of the western boundary around 100 m depth. Modeling results indicate a southward penetration of the Western Boundary Undercurrent (WBUC) below the thermocline, along the North Brazilian coast into the EUC or the North Equatorial Undercurrent (NEUC) (around 48 W-3 N). The WBUC in the region does not flow more south than 3 N. The northern waters are diverted eastward either by the NBC retroflection or by the northern edge of the associated clockwise rings. The existence of subsurface mesoscale rings associated to the NBC retroflection is evidenced, without any signature in the surface layer, so confirming earlier numerical model outputs. These subsurface anticyclones, linked to the NBC/NBUC retroflection into the North Equatorial Undercurrent and the EUC, contribute to the transport of South Atlantic high salinity water into the Northern Hemisphere. (orig.)

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

Science.gov (United States)

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

Retrieving Temperature Anomaly in the Global Subsurface and Deeper Ocean From Satellite Observations

Science.gov (United States)

Su, Hua; Li, Wene; Yan, Xiao-Hai

2018-01-01

Retrieving the subsurface and deeper ocean (SDO) dynamic parameters from satellite observations is crucial for effectively understanding ocean interior anomalies and dynamic processes, but it is challenging to accurately estimate the subsurface thermal structure over the global scale from sea surface parameters. This study proposes a new approach based on Random Forest (RF) machine learning to retrieve subsurface temperature anomaly (STA) in the global ocean from multisource satellite observations including sea surface height anomaly (SSHA), sea surface temperature anomaly (SSTA), sea surface salinity anomaly (SSSA), and sea surface wind anomaly (SSWA) via in situ Argo data for RF training and testing. RF machine-learning approach can accurately retrieve the STA in the global ocean from satellite observations of sea surface parameters (SSHA, SSTA, SSSA, SSWA). The Argo STA data were used to validate the accuracy and reliability of the results from the RF model. The results indicated that SSHA, SSTA, SSSA, and SSWA together are useful parameters for detecting SDO thermal information and obtaining accurate STA estimations. The proposed method also outperformed support vector regression (SVR) in global STA estimation. It will be a useful technique for studying SDO thermal variability and its role in global climate system from global-scale satellite observations.

Origin and geochemistry of saline spring waters in the Athabasca oil sands region, Alberta, Canada

International Nuclear Information System (INIS)

Gue, Anita E.; Mayer, Bernhard; Grasby, Stephen E.

2015-01-01

Highlights: • Saline groundwater enters the Athabasca and Clearwater rivers in the AOSR via springs. • High TDS is due to subsurface dissolution of Devonian evaporites and carbonates. • Low δ 18 O values, and 3 H and 14 C data suggest some Laurentide glacial meltwater input. • Bacterial sulfate reduction, methanogenesis, and CH 4 oxidation were identified. • Metal and PAH contents are reported; bitumen does not appear to be major influence. - Abstract: The geochemistry of saline spring waters in the Athabasca oil sands region (AOSR) in Alberta (Canada) discharging from Devonian carbonate rocks into the Athabasca and Clearwater rivers was characterized for major ions, trace elements, dissolved gases, and polycyclic aromatic hydrocarbons (PAHs). In addition, stable isotope analyses of H 2 O, SO 4 , dissolved inorganic carbon (DIC), Sr, and CH 4 were used to trace the sources of spring waters and their dissolved solutes, and to identify subsurface processes affecting water chemistry. The spring waters had δ 18 O values as low as −23.5‰, suggesting they are composed of up to 75% Laurentide glacial meltwater. Tritium and radiocarbon age-dating results, analyzed for three spring waters, supported a glacial origin. The high salinity of the spring waters (TDS 7210–51,800 mg/L) was due to dissolution of Devonian evaporite and carbonate deposits in the subsurface. Spring waters were affected by bacterial (dissimilatory) sulfate reduction, methanogenesis, and methane oxidation. Trace elements were present in spring waters at varying concentrations, with only one spring containing several predominant oil sands metals (As, Fe, Mo, Ni, Se, Zn) suggesting bitumen as a source. Five springs contained elements (Al, As, B, Fe, Se) at concentrations exceeding water quality guidelines for the protection of aquatic life. Seven PAHs were detected in spring waters (total PAH concentrations ranged from 7.3 to 273.6 ng/L), but most springs contained a maximum of two PAHs

Transboundary geophysical mapping of geological elements and salinity distribution critical for the assessment of future sea water intrusion in response to sea level rise

Directory of Open Access Journals (Sweden)

F. Jørgensen

2012-07-01

Full Text Available Geophysical techniques are increasingly being used as tools for characterising the subsurface, and they are generally required to develop subsurface models that properly delineate the distribution of aquifers and aquitards, salt/freshwater interfaces, and geological structures that affect groundwater flow. In a study area covering 730 km² across the border between Germany and Denmark, a combination of an airborne electromagnetic survey (performed with the SkyTEM system, a high-resolution seismic survey and borehole logging has been used in an integrated mapping of important geological, physical and chemical features of the subsurface. The spacing between flight lines is 200–250 m which gives a total of about 3200 line km. About 38 km of seismic lines have been collected. Faults bordering a graben structure, buried tunnel valleys, glaciotectonic thrust complexes, marine clay units, and sand aquifers are all examples of geological structures mapped by the geophysical data that control groundwater flow and to some extent hydrochemistry. Additionally, the data provide an excellent picture of the salinity distribution in the area and thus provide important information on the salt/freshwater boundary and the chemical status of groundwater. Although the westernmost part of the study area along the North Sea coast is saturated with saline water and the TEM data therefore are strongly influenced by the increased electrical conductivity there, buried valleys and other geological elements are still revealed. The mapped salinity distribution indicates preferential flow paths through and along specific geological structures within the area. The effects of a future sea level rise on the groundwater system and groundwater chemistry are discussed with special emphasis on the importance of knowing the existence, distribution and geometry of the mapped geological elements, and their control on the groundwater salinity distribution is assessed.

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

Science.gov (United States)

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.

Mineralogical correlation of surficial sediment from area drainages with selected sedimentary interbeds at the Idaho National Engineering Laboratory, Idaho

Energy Technology Data Exchange (ETDEWEB)

Bartholomay, R.C.

1990-08-01

Ongoing research by the US Geological Survey at the INEL involves investigation of the migration of radioactive elements contained in low-level radioactive waste, hydrologic and geologic factors affecting waste movement, and geochemical factors that influence the chemical composition of the waste. Identification of the mineralogy of the Snake River Plain is needed to aid in the study of the hydrology and geochemistry of subsurface waste disposal. The US Geological Surveys project office at the Idaho National Engineering Laboratory, in cooperation with the US Department of Energy, used mineralogical data to correlate surficial sediment samples from the Big Lost River, Little Lost River, and Birch Greek drainages with selected sedimentary interbed core samples taken from test holes at the RWMC (Radioactive Waste Management Complex), TRA (Test Reactors Area), ICPP (Idaho Chemical Processing Plant), and TAN (Test Area North). Correlating the mineralogy of a particular present-day drainage area with a particular sedimentary interbed provides information on historical source of sediment for interbeds in and near the INEL. Mineralogical data indicate that surficial sediment samples from the Big Lost River drainage contained a larger amount of feldspar and pyroxene and a smaller amount of calcite and dolomite than samples from the Little Lost River and Birch Creek drainages. Mineralogical data from sedimentary interbeds at the RWMC, TRA, and ICPP correlate with surficial sediment of the present-day big Lost River drainage. Mineralogical data from a sedimentary interbed at TAN correlate with surficial sediment of the present-day Birch Creek drainage. 13 refs., 5 figs., 3 tabs.

Mineralogical correlation of surficial sediment from area drainages with selected sedimentary interbeds at the Idaho National Engineering Laboratory, Idaho

International Nuclear Information System (INIS)

Bartholomay, R.C.

1990-08-01

Ongoing research by the US Geological Survey at the INEL involves investigation of the migration of radioactive elements contained in low-level radioactive waste, hydrologic and geologic factors affecting waste movement, and geochemical factors that influence the chemical composition of the waste. Identification of the mineralogy of the Snake River Plain is needed to aid in the study of the hydrology and geochemistry of subsurface waste disposal. The US Geological Surveys project office at the Idaho National Engineering Laboratory, in cooperation with the US Department of Energy, used mineralogical data to correlate surficial sediment samples from the Big Lost River, Little Lost River, and Birch Greek drainages with selected sedimentary interbed core samples taken from test holes at the RWMC (Radioactive Waste Management Complex), TRA (Test Reactors Area), ICPP (Idaho Chemical Processing Plant), and TAN (Test Area North). Correlating the mineralogy of a particular present-day drainage area with a particular sedimentary interbed provides information on historical source of sediment for interbeds in and near the INEL. Mineralogical data indicate that surficial sediment samples from the Big Lost River drainage contained a larger amount of feldspar and pyroxene and a smaller amount of calcite and dolomite than samples from the Little Lost River and Birch Creek drainages. Mineralogical data from sedimentary interbeds at the RWMC, TRA, and ICPP correlate with surficial sediment of the present-day big Lost River drainage. Mineralogical data from a sedimentary interbed at TAN correlate with surficial sediment of the present-day Birch Creek drainage. 13 refs., 5 figs., 3 tabs

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

Science.gov (United States)

King, Kevin W; Williams, Mark R; Fausey, Norman R

2015-03-01

Phosphorus (P) transport from agricultural fields continues to be a focal point for addressing harmful algal blooms and nuisance algae in freshwater systems throughout the world. In humid, poorly drained regions, attention has turned to P delivery through subsurface tile drainage. However, research on the contributions of tile drainage to watershed-scale P losses is limited. The objective of this study was to evaluate long-term P movement through tile drainage and its manifestation at the watershed outlet. Discharge data and associated P concentrations were collected for 8 yr (2005-2012) from six tile drains and from the watershed outlet of a headwater watershed within the Upper Big Walnut Creek watershed in central Ohio. Results showed that tile drainage accounted for 47% of the discharge, 48% of the dissolved P, and 40% of the total P exported from the watershed. Average annual total P loss from the watershed was 0.98 kg ha, and annual total P loss from the six tile drains was 0.48 kg ha. Phosphorus loads in tile and watershed discharge tended to be greater in the winter, spring, and fall, whereas P concentrations were greatest in the summer. Over the 8-yr study, P transported in tile drains represented 90% of all measured concentrations exceeded recommended levels (0.03 mg L) for minimizing harmful algal blooms and nuisance algae. Thus, the results of this study show that in systematically tile-drained headwater watersheds, the amount of P delivered to surface waters via tile drains cannot be dismissed. Given the amount of P loss relative to typical application rates, development and implementation of best management practices (BMPs) must jointly consider economic and environmental benefits. Specifically, implementation of BMPs should focus on late fall, winter, and early spring seasons when most P loading occurs. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

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

Science.gov (United States)

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.

Transient drainage summary report

International Nuclear Information System (INIS)

1996-09-01

This report summarizes the history of transient drainage issues on the Uranium Mill Tailings Remedial Action (UMTRA) Project. It defines and describes the UMTRA Project disposal cell transient drainage process and chronicles UMTRA Project treatment of the transient drainage phenomenon. Section 4.0 includes a conceptual cross section of each UMTRA Project disposal site and summarizes design and construction information, the ground water protection strategy, and the potential for transient drainage

The foam drainage equation for drainage dynamics in unsaturated porous media

Science.gov (United States)

Lehmann, P.; Hoogland, F.; Assouline, S.; Or, D.

2017-07-01

Similarity in liquid-phase configuration and drainage dynamics of wet foam and gravity drainage from unsaturated porous media expands modeling capabilities for capillary flows and supplements the standard Richards equation representation. The governing equation for draining foam (or a soil variant termed the soil foam drainage equation—SFDE) obviates the need for macroscopic unsaturated hydraulic conductivity function by an explicit account of diminishing flow pathway sizes as the medium gradually drains. The study provides new and simple analytical expressions for drainage rates and volumes from unsaturated porous media subjected to different boundary conditions. Two novel analytical solutions for saturation profile evolution were derived and tested in good agreement with a numerical solution of the SFDE. The study and the proposed solutions rectify the original formulation of foam drainage dynamics of Or and Assouline (2013). The new framework broadens the scope of methods available for quantifying unsaturated flow in porous media, where the intrinsic conductivity and geometrical representation of capillary drainage could improve understanding of colloid and pathogen transport. The explicit geometrical interpretation of flow pathways underlying the hydraulic functions used by the Richards equation offers new insights that benefit both approaches.

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

Science.gov (United States)

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.

Subsurface Contamination Control

Energy Technology Data Exchange (ETDEWEB)

Y. Yuan

2001-12-12

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 the 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

Experiment on Measurement of Interfacial Tension for Subsurface Conditions of Light Oil from Thailand

Directory of Open Access Journals (Sweden)

Jiravivitpanya Jiramet

2017-01-01

Full Text Available One of enhanced oil recovery techniques to increase oil production is surfactant flooding. Surfactants are considered as effective chemical agents used in oilfield in Thailand. It is used to reduce the interfacial tension (IFT of two fluids and to make them flow easier in the reservoir. In this study, Monoethanolamide (MEA commonly used for carbon dioxide capture, is applied as a surfactant to reduce IFT between oil and brine. Therefore, the aim of this work is to investigate and measure the IFT based on the conditions of subsurface at the oilfield in Thailand. These parameters such as temperature, pressure, salinity as well as the concentration of surfactant are adjusted to investigate the effects on IFT reduction. From the results, it is reported that pressure from 1000 to 2000 psi and temperature varied from 70°C to 90°C can reduce IFT insignificantly. However, salinity and surfactant concentration are the main parameters that impact on the IFT reduction. It can greatly decrease IFT up to 87.13% for surfactant concentration and up to 74.06% for salinity. Finally, the results can be applied to use in the real field for enhanced oil production in Thailand.

Geochemistry of silicate-rich rocks can curtail spreading of carbon dioxide in subsurface aquifers.

Science.gov (United States)

Cardoso, S S S; Andres, J T H

2014-12-11

Pools of carbon dioxide are found in natural geological accumulations and in engineered storage in saline aquifers. It has been thought that once this CO2 dissolves in the formation water, making it denser, convection streams will transport it efficiently to depth, but this may not be so. Here, we assess theoretically and experimentally the impact of natural chemical reactions between the dissolved CO2 and the rock formation on the convection streams in the subsurface. We show that, while in carbonate rocks the streaming of dissolved carbon dioxide persists, the chemical interactions in silicate-rich rocks may curb this transport drastically and even inhibit it altogether. These results challenge our view of carbon sequestration and dissolution rates in the subsurface, suggesting that pooled carbon dioxide may remain in the shallower regions of the formation for hundreds to thousands of years. The deeper regions of the reservoir can remain virtually carbon free.

Effects of the Ionosphere on Passive Microwave Remote Sensing of Ocean Salinity from Space

Science.gov (United States)

LeVine, D. M.; Abaham, Saji; Hildebrand, Peter H. (Technical Monitor)

2001-01-01

Among the remote sensing applications currently being considered from space is the measurement of sea surface salinity. The salinity of the open ocean is important for understanding ocean circulation and for modeling energy exchange with the atmosphere. Passive microwave remote sensors operating near 1.4 GHz (L-band) could provide data needed to fill the gap in current coverage and to complement in situ arrays being planned to provide subsurface profiles in the future. However, the dynamic range of the salinity signal in the open ocean is relatively small and propagation effects along the path from surface to sensor must be taken into account. In particular, Faraday rotation and even attenuation/emission in the ionosphere can be important sources of error. The purpose or this work is to estimate the magnitude of these effects in the context of a future remote sensing system in space to measure salinity in L-band. Data will be presented as a function of time location and solar activity using IRI-95 to model the ionosphere. The ionosphere presents two potential sources of error for the measurement of salinity: Rotation of the polarization vector (Faraday rotation) and attenuation/emission. Estimates of the effect of these two phenomena on passive remote sensing over the oceans at L-band (1.4 GHz) are presented.

Bibliography for acid-rock drainage and selected acid-mine drainage issues related to acid-rock drainage from transportation activities

Science.gov (United States)

Bradley, Michael W.; Worland, Scott C.

2015-01-01

Acid-rock drainage occurs through the interaction of rainfall on pyrite-bearing formations. When pyrite (FeS2) is exposed to oxygen and water in mine workings or roadcuts, the mineral decomposes and sulfur may react to form sulfuric acid, which often results in environmental problems and potential damage to the transportation infrastructure. The accelerated oxidation of pyrite and other sulfidic minerals generates low pH water with potentially high concentrations of trace metals. Much attention has been given to contamination arising from acid mine drainage, but studies related to acid-rock drainage from road construction are relatively limited. The U.S. Geological Survey, in cooperation with the Tennessee Department of Transportation, is conducting an investigation to evaluate the occurrence and processes controlling acid-rock drainage and contaminant transport from roadcuts in Tennessee. The basic components of acid-rock drainage resulting from transportation activities are described and a bibliography, organized by relevant categories (remediation, geochemical, microbial, biological impact, and secondary mineralization) is presented.

Impact of hydrogeological factors on groundwater salinization due to ocean-surge inundation

Science.gov (United States)

Yang, Jie; Zhang, Huichen; Yu, Xuan; Graf, Thomas; Michael, Holly A.

2018-01-01

Ocean surges cause seawater inundation of coastal inland areas. Subsequently, seawater infiltrates into coastal aquifers and threatens the fresh groundwater resource. The severity of resulting salinization can be affected by hydrogeological factors including aquifer properties and hydrologic conditions, however, little research has been done to assess these effects. To understand the impacts of hydrogeological factors on groundwater salinization, we numerically simulated an ocean-surge inundation event on a two-dimensional conceptual coastal aquifer using a coupled surface-subsurface approach. We varied model permeability (including anisotropy), inland hydraulic gradient, and recharge rate. Three salinization-assessment indicators were developed, based on flushing time, depth of salt penetration, and a combination of the two, weighted flushing time, with which the impact of hydrogeological factors on groundwater vulnerability to salinization were quantitatively assessed. The vulnerability of coastal aquifers increases with increasing isotropic permeability. Low horizontal permeability (kx) and high vertical permeability (kz) lead to high aquifer vulnerability, and high kx and low kz lead to low aquifer vulnerability. Vulnerability decreases with increasing groundwater hydraulic gradient and increasing recharge rate. Additionally, coastal aquifers with a low recharge rate (R ≤ 300 mm yr-1) may be highly vulnerable to ocean-surge inundation. This study shows how the newly introduced indicators can be used to quantitatively assess coastal aquifer vulnerability. The results are important for global vulnerability assessment of coastal aquifers to ocean-surge inundation.

137Cs distribution and geochemistry of Lena River (Siberia) drainage basin lake sediments

International Nuclear Information System (INIS)

Johnson-Pyrtle, A.; Scott, M.R.; Laing, T.E.; Smol, J.P.

2000-01-01

The Lena River is the second largest river that discharges into the Arctic Ocean. It is therefore important to determine not only the direct impact its discharge has on the 137Cs concentration of the Arctic, but also the potential its drainage basin has as a 137Cs source. 137Cs surface sediment concentrations and inventory values, which range from 4.97 to 338 Bq kg -1 and 357 to 1732 Bq m -2 , respectively, were determined for the Lena River drainage basin lake samples, via gamma analysis. The average geochemical and mineralogical composition of a subset of samples was also determined using neutron activation analysis, X-ray diffraction and X-ray fluorescence spectrometry techniques. Results of these geochemical analyses allowed for the identification of key geochemical factors that influence the distribution of 137Cs in the Lena River drainage basin. 137Cs profiles indicate that Lena River drainage basin lacustrine sediments serve as a record of 137Cs fallout. Based on the downcore 137Cs, %illite, %smectite, %Al and %Mn distribution patterns, it was concluded that a small fraction of non-selectively bound 137Cs was remobilized at depth in some cores. Inconsistencies between the actual 137Cs fallout record and the 137Cs profiles determined for the lake sediments were attributed to 137Cs remobilization in subsurface sediments. In addition to establishing the agreement between the global atmospheric fallout record and the downcore 137Cs distribution patterns determined for these sediments, results indicate that 137Cs deposited during periods of maximum atmospheric release was buried and is not susceptible to surface erosion processes. However, mean 137Cs concentrations of the lacustrine surface sediments (125 Bq kg -1 ) are still significantly higher than those of the nearby Lena River estuary (11.22 Bq kg -1 ) and Laptev Sea (6.00 Bq kg -1 ). Our study suggests that the Lena River drainage basin has the potential to serve as a source of 137Cs to the adjacent Arctic

Land degradation of Taleghan drainage basin, Iran from saline and alkaline marly formations

International Nuclear Information System (INIS)

Zakikhani, K.; Feiznia, S.; Hosseini, S. H.

2009-01-01

In Iran fine-grained, saline, alkaline and erodible Tertiary marly formations are exposed in many geological zones and play important role in the formation of present landforms. They also play important role in degradation of water resources and soils as diffuse sources, they are the main sources of suspension loads of many rivers and are endless sources of sediments for sand dunes. These marly formations are present in Zagros, Central Iran, Alborz and Kopeh Dagh geological Zones and consists of different geological formations such as Gachsaran, Mishan and Razak Formations ( in Zagros), Lower Red and Upper Red Formations ( in Central Iran) and Neogene Red Beds (in Albords and Kopeh Dagh). (Author)

Land degradation of Taleghan drainage basin, Iran from saline and alkaline marly formations

Energy Technology Data Exchange (ETDEWEB)

Zakikhani, K.; Feiznia, S.; Hosseini, S. H.

2009-07-01

In Iran fine-grained, saline, alkaline and erodible Tertiary marly formations are exposed in many geological zones and play important role in the formation of present landforms. They also play important role in degradation of water resources and soils as diffuse sources, they are the main sources of suspension loads of many rivers and are endless sources of sediments for sand dunes. These marly formations are present in Zagros, Central Iran, Alborz and Kopeh Dagh geological Zones and consists of different geological formations such as Gachsaran, Mishan and Razak Formations ( in Zagros), Lower Red and Upper Red Formations ( in Central Iran) and Neogene Red Beds (in Albords and Kopeh Dagh). (Author)

Drainage of radioactive areas

International Nuclear Information System (INIS)

1981-04-01

This Code of Practice covers all the drainage systems which may occur in the radioactive classified area of an establishment, namely surface water, foul, process and radioactive drainage. It also deals with final discharge lines. The Code of Practice concentrates on those aspects of drainage which require particular attention because the systems are in or from radioactive areas and typical illustrations are given in appendices. The Code makes references to sources of information on conventional aspects of drainage design. (author)

Long-term monitoring of nitrate-N transport to drainage from three agricultural clayey till fields

Science.gov (United States)

Ernstsen, V.; Olsen, P.; Rosenbom, A. E.

2015-01-01

The application of nitrogen (N) fertilisers to crops grown on tile-drained fields is necessary to sustain most modern crop production, but poses a risk to the aquatic environment since tile drains facilitate rapid transport pathways with no significant reduction in nitrate. To maintain the water quality of the aquatic environment and the provision of food from highly efficient agriculture in line with the EU's Water Framework Directive and Nitrates Directive, field-scale knowledge is imperative if there is to be differentiated N-regulation in future. This study describes nitrate-N leaching to drainage based on coherent monitoring of nitrate-N concentrations, the climate, the groundwater table and crop-specific parameters obtained over eleven years (2001-2011) at three subsurface-drained clayey till fields (1.3-2.3 ha). The monitoring results showed significant field differences in nitrate-N transport to drainage. Not only were these caused by periods of bare soil after short-season crops and N-fixing crops (pea), which have been shown to generate high nitrate-N concentrations in drainage, but by the hydrogeological field conditions that were shown to be the controlling factor of nitrate-N transport to drainage. The fields had the following characteristics: (A) the lowest mass transport (13 kg N ha-1) and fertiliser input had short-term and low-intensity drainage with the highest nitrate-N concentrations detected, representing 40% of net precipitation (226 mm) combined with low air temperatures, (B) the medium mass transport (14 kg N ha-1) had medium-term and medium-intensity drainage, representing 42% of net precipitation (471 mm) combined with periods of both low and higher air temperatures, (C) the highest mass transport (19 kg N ha-1) had long-term drainage, representing 68% of net precipitation (617 mm), but had the highest potential for in-situ soil denitrification and post-treatment (e.g. constructed wetlands) due to long periods with both high water

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

Science.gov (United States)

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

Subsurface pH and carbonate saturation state of aragonite on the Chinese side of the North Yellow Sea: seasonal variations and controls

Science.gov (United States)

Zhai, W.-D.; Zheng, N.; Huo, C.; Xu, Y.; Zhao, H.-D.; Li, Y.-W.; Zang, K.-P.; Wang, J.-Y.; Xu, X.-M.

2014-02-01

Based upon eight field surveys conducted between May 2011 and May 2012, we investigated seasonal variations in pH, carbonate saturation state of aragonite (Ωarag), and ancillary data on the Chinese side of the North Yellow Sea, a western North Pacific continental margin of major economic importance. Subsurface waters were CO2-undersaturated in May and nearly in equilibrium with atmospheric CO2 in June. From July to October, the fugacity of CO2 (fCO2) of bottom water gradually increased from 438 ± 44 μatm to 630 ± 84 μatm, and pHT decreased from 8.02 ± 0.04 to 7.88 ± 0.06 due to local aerobic remineralization of primary-production-induced biogenic particles. The subsurface community respiration rates in summer and autumn were estimated to be from 0.80 to 1.08 μmol-O2 kg-1 d-1 within a relatively high salinity range of 31.63 to 32.25. From November to May in the next year, however, subsurface fCO2 gradually decreased and pH increased due to cooling and water column ventilation. The corresponding bottom water Ωarag was 1.85 ± 0.21 (May), 1.79 ± 0.24 (June), 1.75 ± 0.27 (July), 1.76 ± 0.29 (August), 1.45 ± 0.31 (October), 1.52 ± 0.25 (November), and 1.41 ± 0.12 (January). Extremely low Ωarag values (from 1.13 to 1.40) were observed mainly in subsurface waters within the high salinity range of 31.63 to 32.25, which covered a major fraction of the study area in October and November. Of the China seas, the North Yellow Sea represents one of the systems most vulnerable to the potential negative effects of ocean acidification.

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

Science.gov (United States)

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.

Subsurface Ventilation System Description Document

Energy Technology Data Exchange (ETDEWEB)

Eric Loros

2001-07-25

The Subsurface Ventilation System supports the construction and operation of the subsurface repository by providing air for personnel and equipment and temperature control for the underground areas. Although the system is located underground, some equipment and features may be housed or located above ground. The system ventilates the underground by providing ambient air from the surface throughout the subsurface development and emplacement areas. The system provides fresh air for a safe work environment and supports potential retrieval operations by ventilating and cooling emplacement drifts. The system maintains compliance within the limits established for approved air quality standards. The system maintains separate ventilation between the development and waste emplacement areas. The system shall remove a portion of the heat generated by the waste packages during preclosure to support thermal goals. The system provides temperature control by reducing drift temperature to support potential retrieval operations. The ventilation system has the capability to ventilate selected drifts during emplacement and retrieval operations. The Subsurface Facility System is the main interface with the Subsurface Ventilation System. The location of the ducting, seals, filters, fans, emplacement doors, regulators, and electronic controls are within the envelope created by the Ground Control System in the Subsurface Facility System. The Subsurface Ventilation System also interfaces with the Subsurface Electrical System for power, the Monitored Geologic Repository Operations Monitoring and Control System to ensure proper and safe operation, the Safeguards and Security System for access to the emplacement drifts, the Subsurface Fire Protection System for fire safety, the Emplacement Drift System for repository performance, and the Backfill Emplacement and Subsurface Excavation Systems to support ventilation needs.

Subsurface Ventilation System Description Document

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-10-12

The Subsurface Ventilation System supports the construction and operation of the subsurface repository by providing air for personnel and equipment and temperature control for the underground areas. Although the system is located underground, some equipment and features may be housed or located above ground. The system ventilates the underground by providing ambient air from the surface throughout the subsurface development and emplacement areas. The system provides fresh air for a safe work environment and supports potential retrieval operations by ventilating and cooling emplacement drifts. The system maintains compliance within the limits established for approved air quality standards. The system maintains separate ventilation between the development and waste emplacement areas. The system shall remove a portion of the heat generated by the waste packages during preclosure to support thermal goals. The system provides temperature control by reducing drift temperature to support potential retrieval operations. The ventilation system has the capability to ventilate selected drifts during emplacement and retrieval operations. The Subsurface Facility System is the main interface with the Subsurface Ventilation System. The location of the ducting, seals, filters, fans, emplacement doors, regulators, and electronic controls are within the envelope created by the Ground Control System in the Subsurface Facility System. The Subsurface Ventilation System also interfaces with the Subsurface Electrical System for power, the Monitored Geologic Repository Operations Monitoring and Control System to ensure proper and safe operation, the Safeguards and Security System for access to the emplacement drifts, the Subsurface Fire Protection System for fire safety, the Emplacement Drift System for repository performance, and the Backfill Emplacement and Subsurface Excavation Systems to support ventilation needs.

Subsurface Facility System Description Document

International Nuclear Information System (INIS)

Eric Loros

2001-01-01

The Subsurface Facility System encompasses the location, arrangement, size, and spacing of the underground openings. This subsurface system includes accesses, alcoves, and drifts. This system provides access to the underground, provides for the emplacement of waste packages, provides openings to allow safe and secure work conditions, and interfaces with the natural barrier. This system includes what is now the Exploratory Studies Facility. The Subsurface Facility System physical location and general arrangement help support the long-term waste isolation objectives of the repository. The Subsurface Facility System locates the repository openings away from main traces of major faults, away from exposure to erosion, above the probable maximum flood elevation, and above the water table. The general arrangement, size, and spacing of the emplacement drifts support disposal of the entire inventory of waste packages based on the emplacement strategy. The Subsurface Facility System provides access ramps to safely facilitate development and emplacement operations. The Subsurface Facility System supports the development and emplacement operations by providing subsurface space for such systems as ventilation, utilities, safety, monitoring, and transportation

Intelligent SUBsurface Quality : Intelligent use of subsurface infrastructure for surface quality

NARCIS (Netherlands)

Hooimeijer, F.L.; Kuzniecow Bacchin, T.; Lafleur, F.; van de Ven, F.H.M.; Clemens, F.H.L.R.; Broere, W.; Laumann, S.J.; Klaassen, R.G.; Marinetti, C.

2016-01-01

This project focuses on the urban renewal of (delta) metropolises and concentrates on the question how to design resilient, durable (subsurface) infrastructure in urban renewal projects using parameters of the natural system – linking in an efficient way (a) water cycle, (b) soil and subsurface

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

Science.gov (United States)

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.

Deep subsurface microbial processes

Science.gov (United States)

Lovley, D.R.; Chapelle, F.H.

1995-01-01

Information on the microbiology of the deep subsurface is necessary in order to understand the factors controlling the rate and extent of the microbially catalyzed redox reactions that influence the geophysical properties of these environments. Furthermore, there is an increasing threat that deep aquifers, an important drinking water resource, may be contaminated by man's activities, and there is a need to predict the extent to which microbial activity may remediate such contamination. Metabolically active microorganisms can be recovered from a diversity of deep subsurface environments. The available evidence suggests that these microorganisms are responsible for catalyzing the oxidation of organic matter coupled to a variety of electron acceptors just as microorganisms do in surface sediments, but at much slower rates. The technical difficulties in aseptically sampling deep subsurface sediments and the fact that microbial processes in laboratory incubations of deep subsurface material often do not mimic in situ processes frequently necessitate that microbial activity in the deep subsurface be inferred through nonmicrobiological analyses of ground water. These approaches include measurements of dissolved H2, which can predict the predominant microbially catalyzed redox reactions in aquifers, as well as geochemical and groundwater flow modeling, which can be used to estimate the rates of microbial processes. Microorganisms recovered from the deep subsurface have the potential to affect the fate of toxic organics and inorganic contaminants in groundwater. Microbial activity also greatly influences 1 the chemistry of many pristine groundwaters and contributes to such phenomena as porosity development in carbonate aquifers, accumulation of undesirably high concentrations of dissolved iron, and production of methane and hydrogen sulfide. Although the last decade has seen a dramatic increase in interest in deep subsurface microbiology, in comparison with the study of

A Search for Freshwater in the Saline Aquifers of Coastal Bangladesh

Science.gov (United States)

Peters, C.; Hornberger, G. M.

2017-12-01

Can we locate pockets of freshwater amidst brackish groundwater in remote villages in Bangladesh? This study explores what we can infer about local groundwater-surface water (GW-SW) interactions in the polders of coastal Bangladesh. In this underdeveloped region, the shallow groundwater is primarily brackish with unpredictable apportioning of freshwater pockets. We use transects of piezometers, cores, electromagnetic induction, and water chemistry surveys to explore two sources of potential fresh groundwater: (1) tidal channel-aquifer exchange and (2) meteoric recharge. Freshwater is difficult to find due to disparate subsurface lithology, asymmetrical tidal dynamics, extreme seasonal fluctuations in rainfall, and limited field data. Observations suggest substantial lateral variability in shallow subsurface conductivity profiles as well as tidal pressure signals in piezometers. Nevertheless, active exchange of freshwater may be limited due to low permeability of banks and surface sediments limits. Small scale heterogeneity in delta formation likely caused much of the groundwater salinity variation. Without adequate ground truthing of groundwater quality, the ability to deduce the exact location of freshwater pockets may be restricted.

A Review of Ocean/Sea Subsurface Water Temperature Studies from Remote Sensing and Non-Remote Sensing Methods

Directory of Open Access Journals (Sweden)

Elahe Akbari

2017-12-01

Full Text Available Oceans/Seas are important components of Earth that are affected by global warming and climate change. Recent studies have indicated that the deeper oceans are responsible for climate variability by changing the Earth’s ecosystem; therefore, assessing them has become more important. Remote sensing can provide sea surface data at high spatial/temporal resolution and with large spatial coverage, which allows for remarkable discoveries in the ocean sciences. The deep layers of the ocean/sea, however, cannot be directly detected by satellite remote sensors. Therefore, researchers have examined the relationships between salinity, height, and temperature of the oceans/Seas to estimate their subsurface water temperature using dynamical models and model-based data assimilation (numerical based and statistical approaches, which simulate these parameters by employing remotely sensed data and in situ measurements. Due to the requirements of comprehensive perception and the importance of global warming in decision making and scientific studies, this review provides comprehensive information on the methods that are used to estimate ocean/sea subsurface water temperature from remotely and non-remotely sensed data. To clarify the subsurface processes, the challenges, limitations, and perspectives of the existing methods are also investigated.

Structure and evolution of the drainage system of a Himalayan debris-covered glacier, and its relationship with patterns of mass loss

Science.gov (United States)

Benn, Douglas I.; Thompson, Sarah; Gulley, Jason; Mertes, Jordan; Luckman, Adrian; Nicholson, Lindsey

2017-09-01

We provide the first synoptic view of the drainage system of a Himalayan debris-covered glacier and its evolution through time, based on speleological exploration and satellite image analysis of Ngozumpa Glacier, Nepal. The drainage system has several linked components: (1) a seasonal subglacial drainage system below the upper ablation zone; (2) supraglacial channels, allowing efficient meltwater transport across parts of the upper ablation zone; (3) sub-marginal channels, allowing long-distance transport of meltwater; (4) perched ponds, which intermittently store meltwater prior to evacuation via the englacial drainage system; (5) englacial cut-and-closure conduits, which may undergo repeated cycles of abandonment and reactivation; and (6) a "base-level" lake system (Spillway Lake) dammed behind the terminal moraine. The distribution and relative importance of these elements has evolved through time, in response to sustained negative mass balance. The area occupied by perched ponds has expanded upglacier at the expense of supraglacial channels, and Spillway Lake has grown as more of the glacier surface ablates to base level. Subsurface processes play a governing role in creating, maintaining, and shutting down exposures of ice at the glacier surface, with a major impact on spatial patterns and rates of surface mass loss. Comparison of our results with observations on other glaciers indicate that englacial drainage systems play a key role in the response of debris-covered glaciers to sustained periods of negative mass balance.

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

Science.gov (United States)

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

Deep subsurface drip irrigation using coal-bed sodic water: part II. geochemistry

Science.gov (United States)

Bern, Carleton R.; Breit, George N.; Healy, Richard W.; Zupancic, John W.

2013-01-01

Waters with low salinity and high sodium adsorption ratios (SARs) present a challenge to irrigation because they degrade soil structure and infiltration capacity. In the Powder River Basin of Wyoming, such low salinity (electrical conductivity, EC 2.1 mS cm-1) and high-SAR (54) waters are co-produced with coal-bed methane and some are used for subsurface drip irrigation(SDI). The SDI system studied mixes sulfuric acid with irrigation water and applies water year-round via drip tubing buried 92 cm deep. After six years of irrigation, SAR values between 0 and 30 cm depth (0.5-1.2) are only slightly increased over non-irrigated soils (0.1-0.5). Only 8-15% of added Na has accumulated above the drip tubing. Sodicity has increased in soil surrounding the drip tubing, and geochemical simulations show that two pathways can generate sodic conditions. In soil between 45-cm depth and the drip tubing, Na from the irrigation water accumulates as evapotranspiration concentrates solutes. SAR values >12, measured by 1:1 water-soil extracts, are caused by concentration of solutes by factors up to 13. Low-EC (-1) is caused by rain and snowmelt flushing the soil and displacing ions in soil solution. Soil below the drip tubing experiences lower solute concentration factors (1-1.65) due to excess irrigation water and also contains relatively abundant native gypsum (2.4 ± 1.7 wt.%). Geochemical simulations show gypsum dissolution decreases soil-water SAR to 14 and decreasing EC in soil water to 3.2 mS cm-1. Increased sodicity in the subsurface, rather than the surface, indicates that deep SDI can be a viable means of irrigating with sodic waters.

Active microbial community structure of deep subsurface sediments within Baltic Sea Basin

Science.gov (United States)

Reese, B. K.; Zinke, L.; Carvalho, G.; Lloyd, K. G.; Marshall, I.; Shumaker, A.; Amend, J.

2014-12-01

The Baltic Sea Basin (BSB) is a unique depositional setting that has experienced periods of glaciation and deglaciation as a result of climatic fluctuations over past tens of thousands of years. This has resulted in laminated sediments formed during periods with strong permanent salinity stratification. The high sedimentation rates make this an ideal setting to understand the microbial structure of a deep biosphere community in a relatively high carbon, and thus high-energy environment, compared to other deep subsurface sites. Samples were collected through scientific drilling during the International Ocean Discovery Program (IODP) Expedition 347 on board the Greatship Manisha, September-November 2013. We examined the active microbial community structure using the 16S rRNA gene transcript and active functional genes through metatranscriptome sequencing. Major biogeochemical shifts have been observed in response to the depositional history between the limnic, brackish, and marine phases. The active microbial community structure in the BSB is diverse and reflective of the unique changes in the geochemical profile. These data further refine our understanding of the existence life in the deep subsurface and the survival mechanisms required for this extreme environment.

Estimates of deep drainage rates at the U.S. Department of Energy Pantex Plant, Amarillo, Texas

International Nuclear Information System (INIS)

Fayer, M.J.; Richmond, M.C.; Wigmosta, M.S.; Kelley, M.E.

1998-04-01

In FY 1996, the Pacific Northwest National Laboratory (PNNL) provided technical assistance to Battelle Columbus Operations (BCO) in their ongoing assessment of contaminant migration at the Pantex Plant in Amarillo, Texas. The objective of this report is to calculate deep drainage rates at the Pantex Plant. These deep drainage rates may eventually be used to predict contaminant loading to the underlying unconfined aquifer for the Pantex Plant Baseline Risk Assessment. These rates will also be used to support analyses of remedial activities involving surface alterations or the subsurface injection withdrawal of liquids or gases. The scope of this report is to estimate deep drainage rates for the major surface features at the Pantex Plant, including ditches and playas, natural grassland, dryland crop rotation, unvegetated soil, and graveled surfaces. Areas such as Pantex Lake that are outside the main plant boundaries were not included in the analysis. All estimates were derived using existing data or best estimates; no new data were collected. The modeling framework used to estimate the rates is described to enable future correlations, improvements, and enhancements. The scope of this report includes only data gathered during FY 1996. However, a current review of the data gathered on weather, soil, plants, and other information in the time period since did not reveal anything that would significantly alter the results presented in this report

A geochemical approach to determine sources and movement of saline groundwater in a coastal aquifer.

Science.gov (United States)

Anders, Robert; Mendez, Gregory O; Futa, Kiyoto; Danskin, Wesley R

2014-01-01

Geochemical evaluation of the sources and movement of saline groundwater in coastal aquifers can aid in the initial mapping of the subsurface when geological information is unavailable. Chloride concentrations of groundwater in a coastal aquifer near San Diego, California, range from about 57 to 39,400 mg/L. On the basis of relative proportions of major-ions, the chemical composition is classified as Na-Ca-Cl-SO4, Na-Cl, or Na-Ca-Cl type water. δ(2)H and δ(18)O values range from -47.7‰ to -12.8‰ and from -7.0‰ to -1.2‰, respectively. The isotopically depleted groundwater occurs in the deeper part of the coastal aquifer, and the isotopically enriched groundwater occurs in zones of sea water intrusion. (87)Sr/(86)Sr ratios range from about 0.7050 to 0.7090, and differ between shallower and deeper flow paths in the coastal aquifer. (3)H and (14)C analyses indicate that most of the groundwater was recharged many thousands of years ago. The analysis of multiple chemical and isotopic tracers indicates that the sources and movement of saline groundwater in the San Diego coastal aquifer are dominated by: (1) recharge of local precipitation in relatively shallow parts of the flow system; (2) regional flow of recharge of higher-elevation precipitation along deep flow paths that freshen a previously saline aquifer; and (3) intrusion of sea water that entered the aquifer primarily during premodern times. Two northwest-to-southeast trending sections show the spatial distribution of the different geochemical groups and suggest the subsurface in the coastal aquifer can be separated into two predominant hydrostratigraphic layers. © 2013, National Ground Water Association.

In-office drainage of sinus Mucoceles: An alternative to operating-room drainage.

Science.gov (United States)

Barrow, Emily M; DelGaudio, John M

2015-05-01

Endoscopic drainage has become the standard of care for the treatment of mucoceles. In many patients this can be performed in the office. This study reviews our experience with in-office endoscopic mucocele drainage. Retrospective chart review. A retrospective review of one surgeon's experience with in-office endoscopic drainage of sinus mucoceles between 2006 and 2014 was performed. Charts were reviewed for patient demographics, previous surgery, mucocele location, bone erosion, and outcomes. Thirty-two patients underwent 36 in-office drainage procedures. All procedures were performed under topical/local anesthesia. The mean age was 55 years (range, 17-92 years). The mean follow-up time was 444 days. Fifty-five percent had previous sinus surgery. The primary sinus involved was the frontal (12), anterior (11), posterior ethmoid (six), maxillary (four), and sphenoid (two). Bone erosion was noted to be present on computed tomography in 18 mucoceles (51%) (16 orbital, seven skull-base). All mucoceles were successfully accessed in the office with the exception of one, which was aborted due to neo-osteogenesis. Five patients (14% of mucoceles) required additional surgery, two for mucocele recurrence and three for septated mucoceles not completely drained in the office. No treatment complications occurred. All but one patient preferred in-office to operating-room drainage. In-office drainage of sinus mucoceles is well tolerated by patients, with high success and low complication rates, even in large mucoceles with bone erosion. The presence of septations and neo-osteogenesis reduce the likelihood of complete drainage and are relative contraindications. Orbital and skull base erosion are not contraindications. 4. © 2014 The American Laryngological, Rhinological and Otological Society, Inc.

Cultivation of cherry tomato under irrigation with saline water and nitrogen fertilization

Directory of Open Access Journals (Sweden)

Ianne G. S. Vieira

2016-01-01

Full Text Available ABSTRACT The study was carried out from August 2013 to January 2014 to evaluate growth and production of cherry tomato cultivated under irrigation with water of different salinity levels and fertilized with different nitrogen (N doses, in experiment conducted in drainage lysimeters under greenhouse conditions, at the Center for Agrifood Science and Technology of the Federal University of Campina Grande. The statistical design was randomized blocks in a 5 x 4 factorial scheme, with three replicates, and the treatments consisted of five levels of electrical conductivity of water (0.3, 1.5, 2.5, 3.5 and 4.5 dS m-1 and four N doses (60, 100, 140 and 180 mg kg-1. Growth and production variables of cherry tomato decrease linearly from the irrigation water salinity of 0.3 dS m-1 on. The longer exposure of plants to salt stress caused the highest reductions, and the root dry matter, leaf area and the number of clusters are the most sensitive variables. The highest value of plant height at 125 days after transplantation was obtained with the N dose of 139 mg kg-1 of soil. Increasing N doses reduced the effect of salinity on cherry tomato growth at 125 days after transplantation.

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

Science.gov (United States)

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.

Percutaneous drainage of lung abscesses

International Nuclear Information System (INIS)

van Sonnenberg, E.; D'Agostino, H.; Casola, G.; Vatney, R.R.; Wittich, G.R.; Harker, C.

1989-01-01

The authors performed percutaneous drainage of lung abscesses in 12 patients. Indications for drainage were septicemia and persistence or worsening of radiographic findings. These lung abscesses were refractory to intravenous antibiotics and to bronchial toilet. Etiology of the abscesses included pneumonia (most frequently), trauma, postoperative development, infected necrotic neoplasm, and infected sequestration. Guidelines for drainage included passage of the catheter through contiguously abnormal lung and pleura, inability of the patient to cough, and/or bronchial obstruction precluding bronchial drainage. Cure was achieved in 11 of 12 patients. Catheters were removed on an average of 16 days after insertion. Antibiotics were administered an average of 18 days before drainage. No major complications occurred

Percutaneous catheter drainage of lung abscess

Energy Technology Data Exchange (ETDEWEB)

Kim, Young Shin; Chun, Kyung Ah; Choi, Hyo Sun; Ha, Hyun Kown; Shinn, Kyung Sub [Catholic University Medical college, Seoul (Korea, Republic of)

1993-09-15

From March 1987 to July 1989, six patients (five adults and one child) with lung abscess (size, 5-13 cm in diameter) were treated with percutaneous aspiration and drainage. In each case, the puncture was made where the wall of the abscess was in contact with the pleural surface. An 8 to 10 Fr cartheter was inserted for drainage. Five of 6 had a dynamatic clinical response within 24 hours of the drainage. Percutaneous drainage was successful with complete abscess resolution in four and partial resolution in one patient. No response was seen in the rest one. The duration of drainage ranged from 7 to 18 days(average, 15.5 days) in successful cases. One case of the failure in drainage was due tio persistent aspiration of the neurologically impaired patient. In one patient, the abscess resolved after drainage but recurred after inadvertent removal of the catheter 7 days after insertion. In two patients, concurrent pleural empyema was resolved completely by the drainage. Computed tomography provide anatomic details necessary for choosing the puncture site and avoiding a puncture of the lung parenchyma. Percutaneous catheter drainage is safe and effective method for treating patient with lung abscess.

Percutaneous catheter drainage of lung abscess

International Nuclear Information System (INIS)

Kim, Young Shin; Chun, Kyung Ah; Choi, Hyo Sun; Ha, Hyun Kown; Shinn, Kyung Sub

1993-01-01

From March 1987 to July 1989, six patients (five adults and one child) with lung abscess (size, 5-13 cm in diameter) were treated with percutaneous aspiration and drainage. In each case, the puncture was made where the wall of the abscess was in contact with the pleural surface. An 8 to 10 Fr cartheter was inserted for drainage. Five of 6 had a dynamatic clinical response within 24 hours of the drainage. Percutaneous drainage was successful with complete abscess resolution in four and partial resolution in one patient. No response was seen in the rest one. The duration of drainage ranged from 7 to 18 days(average, 15.5 days) in successful cases. One case of the failure in drainage was due tio persistent aspiration of the neurologically impaired patient. In one patient, the abscess resolved after drainage but recurred after inadvertent removal of the catheter 7 days after insertion. In two patients, concurrent pleural empyema was resolved completely by the drainage. Computed tomography provide anatomic details necessary for choosing the puncture site and avoiding a puncture of the lung parenchyma. Percutaneous catheter drainage is safe and effective method for treating patient with lung abscess

SUBSURFACE REPOSITORY INTEGRATED CONTROL SYSTEM DESIGN

International Nuclear Information System (INIS)

Randle, D.C.

2000-01-01

The primary purpose of this document is to develop a preliminary high-level functional and physical control system architecture for the potential repository at Yucca Mountain. This document outlines an overall control system concept that encompasses and integrates the many diverse process and communication systems being developed for the subsurface repository design. This document presents integrated design concepts for monitoring and controlling the diverse set of subsurface operations. The Subsurface Repository Integrated Control System design will be composed of a series of diverse process systems and communication networks. The subsurface repository design contains many systems related to instrumentation and control (I andC) for both repository development and waste emplacement operations. These systems include waste emplacement, waste retrieval, ventilation, radiological and air monitoring, rail transportation, construction development, utility systems (electrical, lighting, water, compressed air, etc.), fire protection, backfill emplacement, and performance confirmation. Each of these systems involves some level of I andC and will typically be integrated over a data communications network throughout the subsurface facility. The subsurface I andC systems will also interface with multiple surface-based systems such as site operations, rail transportation, security and safeguards, and electrical/piped utilities. In addition to the I andC systems, the subsurface repository design also contains systems related to voice and video communications. The components for each of these systems will be distributed and linked over voice and video communication networks throughout the subsurface facility. The scope and primary objectives of this design analysis are to: (1) Identify preliminary system-level functions and interfaces (Section 6.2). (2) Examine the overall system complexity and determine how and on what levels the engineered process systems will be monitored

Oxygation enhances growth, gas exchange and salt tolerance of vegetable soybean and cotton in a saline vertisol.

Science.gov (United States)

Bhattarai, Surya P; Midmore, David J

2009-07-01

Impacts of salinity become severe when the soil is deficient in oxygen. Oxygation (using aerated water for subsurface drip irrigation of crop) could minimize the impact of salinity on plants under oxygen-limiting soil environments. Pot experiments were conducted to evaluate the effects of oxygation (12% air volume/volume of water) on vegetable soybean (moderately salt tolerant) and cotton (salt tolerant) in a salinized vertisol at 2, 8, 14, 20 dS/m EC(e). In vegetable soybean, oxygation increased above ground biomass yield and water use efficiency (WUE) by 13% and 22%, respectively, compared with the control. Higher yield with oxygation was accompanied by greater plant height and stem diameter and reduced specific leaf area and leaf Na+ and Cl- concentrations. In cotton, oxygation increased lint yield and WUE by 18% and 16%, respectively, compared with the control, and was accompanied by greater canopy light interception, plant height and stem diameter. Oxygation also led to a greater rate of photosynthesis, higher relative water content in the leaf, reduced crop water stress index and lower leaf water potential. It did not, however, affect leaf Na+ or Cl- concentration. Oxygation invariably increased, whereas salinity reduced the K+ : Na+ ratio in the leaves of both species. Oxygation improved yield and WUE performance of salt tolerant and moderately tolerant crops under saline soil environments, and this may have a significant impact for irrigated agriculture where saline soils pose constraints to crop production.

Application of wastewater with high organic load for saline-sodic soil reclamation focusing on soil purification ability

Directory of Open Access Journals (Sweden)

M.A. Kameli

2017-04-01

Full Text Available Fresh water source scarcity in arid and semiarid area is limitation factor for saline-sodic soil reclamation. The reusing of agricultural drainage and industrial wastewater are preferred strategies for combating with this concern. The objective of current study was evaluation in application of industrial sugar manufacture wastewater due to high soluble organic compounds in saline-sodic and sodic soil. Also soil ability in wastewater organic compounds removal was second aim of present study. Saline-sodic and sodic soil sample was leached in soil column by diluted wastewater of amirkabir sugar manufacture in Khuzestan Province of Iran at constant water head. Sodium, electric conductivity and chemical oxygen demand of soil column leachate were measured per each pore volume. The experimental kinetics of wastewater organic compounds on two saline-sodic and sodic soil were also investigated by three pseudo second order, intra particle diffusion and elovich model. The results of current study showed that electric conductivity of saline-sodic soil was decreased to 90% during 3 initial pore volumes, from other side exchangeable sodium percent of saline-sodic and sodic soil decreased 30 and 71 percent, respectively. There were no significant different between wastewater chemical oxygen demand removal by saline-sodic and sodic soil in both batch and column studies. Wastewater chemical oxygen demand was decreased to 35% during pass through soil column. The results showed that the adsorption kinetics of wastewater organic compounds were best fitted by the pseudo-second order model with 99 percent correlation coefficient (r2=0.99%.

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

Science.gov (United States)

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.

Geoelectric imaging for saline water intrusion in Geopark zone of Ciletuh Bay, Indonesia

Science.gov (United States)

Ardi, N. D.; Iryanti, M.; Asmoro, C. P.; Yusuf, A.; Sundana, A. N. A.; Safura, H. Y.; Fitri, M.; Anggraeni, M.; Kurniawan, R.; Afrianti, R.; Sumarni

2018-05-01

Saline water intrusion in estuary is an urgent ecological encounter across the world. The Ciletuh Bay, located in the southern Sukabumi district, is an area with high cultivated potential becoming one of the most important geology tourism zones in Indonesia. However, salt water intrusion along the creek is a natural spectacle that disturbs the economic growth of the whole region. This research was intended at plotting the subsurface level of saltwater interventions into aquifers at the northern part of Ciletuh creek, Indonesia. The study implemented geoelectric imaging methods. 37 imaging datum were acquired using Wenner array configuration. The saline water were identified across the study area. The result of two dimensional cross-sectional resistivity shows that there is an indication of sea content in our measured soil, i.e. the smallest resistivity value is 0.579 Ωm found at a depth of 12.4 m to 19.8 m at a track length of 35 m to 60 m is categorized in the clayey which shows low groundwater quality. However, when compared with the results of direct observation of groundwater from the wells of residents, the water obtained is brackish water. A water chemistry test is conducted to ascertain the initial results of this method so that a potential sea intrusion potential map can be interpreted more clearly. This can consequently help as an extrapolative model to define depth to saline water at any site within the saline water zone in the study area.

Drainage, liming and fertilization of organic soils. 1. Long-term effects on acid/base relations

International Nuclear Information System (INIS)

Braekke, F.H.

1999-01-01

Long-term changes of the acid/base relations of organic soils after drainage, fertilization and/or liming at three experimental sites - two ombrogenous and one soligenous - in south-central Norway are discussed. These sites were drained, fertilized and/or limed in 1953-1956 and sampled in 1991-1992. Drainage at the ombrogenous sites caused: insignificant shifts of pH, higher bulk densities to 40 cm depth, higher ash percentage, higher contents of N and P to 20 cm depth and reduced concentrations of total Ca, K, Mg, Na, Al and Fe in soil layers deeper than 20 cm. The soligenous site was not effectively drained; despite this, pH dropped about 0.5 unit in the surface and subsurface soil layers of the control plots, while small changes were measured for most other soil variables. The suggested reason for the pH drop is limited sulphide oxidation in the upper 20 cm drained layer. Base saturation at actual soil pH, when all treatments were included, was estimated with good precision by four regressors: pH, extractable Al, extractable Fe and extractable Ca (R 2 = 0.90-0.95). Similar models explained 97-99% of the variation in base saturation at soil pH = 7.0. The lime effects at the properly drained oligotrophic sites were proportional to applied doses; for pH to 40 cm, base saturation to 60 cm, and Ca concentration to 60 cm depth. At the less well-drained soligenous site, effects were limited to the upper 30 cm layer. Both drainage and liming caused higher cation exchange capacities and proper drainage seems to be a prerequisite for the liming effect. Estimated recovery of calcium to 60 cm depth was 64-79% at the ombrogenous sites and 42-46% at the soligenous site 28 refs, 3 figs, 8 tabs

Routine Sub-hepatic Drainage versus No Drainage after Laparoscopic Cholecystectomy: Open, Randomized, Clinical Trial.

Science.gov (United States)

Shamim, Muhammad

2013-02-01

Surgeons are still following the old habit of routine subhepatic drainage following laparoscopic cholecystectomy (LC). This study aims to compare the outcome of subhepatic drainage with no drainage after LC. This prospective study was conducted in two phases. Phase I was open, randomized controlled trial (RCT), conducted in Civil Hospital Karachi, from August 2004 to June 2005. Phase II was descriptive case series, conducted in author's practice hospitals of Karachi, from July 2005 to December 2009. In phase I, 170 patients with chronic calculous cholecystitis underwent LC. Patients were divided into two groups, subhepatic drainage (group A: 79 patients) or no drainage (group B: 76 patients). The rest 15 patients were excluded either due to conversion or elective subhepatic drainage. In phase II, 218 consecutive patients were enrolled, who underwent LC with no subhepatic drainage. Duration of operation, character, and amount of drain fluid (if placed), postoperative ultrasound for subhepatic collection, postoperative chest X-ray for the measurement of subdiaphragmatic air, postoperative pain, postoperative nausea/vomiting, duration of hospital stay, and preoperative or postoperative complications were noted and analyzed. Duration of operation and hospital stay was slightly longer in group A patients (P values 0.002 and 0.029, respectively); postoperative pain perception, nausea/vomiting, and postoperative complications were nearly same in both groups (P value 0.064, 0.078, and 0.003, respectively). Subhepatic fluid collection was more in group A (P = 0.002), whereas subdiaphragmatic air collection was more in group B (P = 0.003). Phase II results were nearly similar to group B patients in phase I. Routine subhepatic drainage after LC is not necessary in uncomplicated cases.

Climatology and seasonality of upper ocean salinity: a three-dimensional view from argo floats

Science.gov (United States)

Chen, Ge; Peng, Lin; Ma, Chunyong

2018-03-01

Primarily due to the constraints of observation technologies (both field and satellite measurements), our understanding of ocean salinity is much less mature compared to ocean temperature. As a result, the characterizations of the two most important properties of the ocean are unfortunately out of step: the former is one generation behind the latter in terms of data availability and applicability. This situation has been substantially changed with the advent of the Argo floats which measure the two variables simultaneously on a global scale since early this century. The first decade of Argo-acquired salinity data are analyzed here in the context of climatology and seasonality, yielding the following main findings for the global upper oceans. First, the six well-defined "salty pools" observed around ±20° in each hemisphere of the Pacific, Atlantic and Indian Oceans are found to tilt westward vertically from the sea surface to about 600 m depth, forming six saline cores within the subsurface oceans. Second, while potential temperature climatology decreases monotonically to the bottom in most places of the ocean, the vertical distribution of salinity can be classified into two categories: A double-halocline type forming immediately above and below the local salinity maximum around 100-150 m depths in the tropical and subtropical oceans, and a single halocline type existing at about 100 m depth in the extratropical oceans. Third, in contrast to the midlatitude dominance for temperature, seasonal variability of salinity in the oceanic mixed layer has a clear tropical dominance. Meanwhile, it is found that a two-mode structure with annual and semiannual periodicities can effectively penetrate through the upper ocean into a depth of 2000 m. Fourth, signature of Rossby waves is identified in the annual phase map of ocean salinity within 200-600 m depths in the tropical oceans, revealing a strongly co-varying nature of ocean temperature and salinity at specific depths

The Effect of Water Table Fluctuation and its Salinity on Fe Crystal and Noncrystal in some Khuzestan Soils

Directory of Open Access Journals (Sweden)

mostafa Pajohannia

2017-01-01

-tionite treatments was different regarding the salinity, texture, organic matters, cultivation and the water table fluctuation. The total Fe content in the middle layers had permanently increased due to the groundwater fluctuation levels and this caused the creation of mottle in this layer. All saline soils had saline subsurface water. The salinity has caused that the effective microorganisms have not been actived on the reduction processes in some profiles and the Fe deposit more in the Fe3+forms. The Fe was found more in non-crystal form in saline regions, but it was in the crystal form in non-saline regions which indicated the suitable conditions for Fe’s nodule formation. For example, when soil salinity decreased from 14.9 to 8.1 dS/m, Fec increased from 460.1 to 497.8 mg/kg soil. With increasing the amount of clay, and cultivation periods, the Fed content has also been increased. The Feo/ Fec ratio in undevelopted soils was higher than developed soils. This ratio was low in non-saline soil and was high for saline soil. this indicates that non-saline soil had more development than saline soils. The maximum amount (1.6 was belonged to saline soil and minimum was for no saline soils. With increasing in soil age, tillage periods and clay content this ratio was decreased., statistical analysis Also showed that there was significant difference between Fec and Feo in saline and no saline soils. Also, with increasing in salinity, Fec content decreased and Feo increased. aggregate stability was also increased with increasing Fec content. Conclusions: The Feo content was more in surface of saline soil than subsurface when pedon was ponded and saturated from surface. Feo was very higher in saline soils than no saline soils. Fec had not significant difference between saline and nonsaline soils. Salinity decreased Fec and increased Feo content in soils. Feo/Fec ratio of saline soils was 4 to 5 times fold of non-saline soils. Increasing Feo/Fec ratio in saline soils and decreasing in this

Endoscopic Ultrasound-Guided Perirectal Abscess Drainage without Drainage Catheter: A Case Series

Directory of Open Access Journals (Sweden)

Eun Kwang Choi

2017-05-01

Full Text Available A perirectal abscess is a relatively common disease entity that occurs as a postsurgical complication or as a result of various medical conditions. Endoscopic ultrasound (EUS-guided drainage was recently described as a promising alternative treatment. Previous reports have recommended placement of a drainage catheter through the anus for irrigation, which is inconvenient to the patient and carries a risk of accidental dislodgement. We report four cases of perirectal abscess that were successfully treated with only one or two 7 F double pigtail plastic stent placements and without a drainage catheter for irrigation.

Concentration and characterization of dissolved organic matter in the surface microlayer and subsurface water of the Bohai Sea, China

Science.gov (United States)

Chen, Yan; Yang, Gui-Peng; Wu, Guan-Wei; Gao, Xian-Chi; Xia, Qing-Yan

2013-01-01

A total of 19 sea-surface microlayer and corresponding subsurface samples collected from the Bohai Sea, China in April 2010 were analyzed for chlorophyll a, dissolved organic carbon (DOC) and its major compound classes including total dissolved carbohydrates (TDCHO, including monosaccharides, MCHO, and polysaccharides, PCHO) and total hydrolysable amino acids (THAA, including dissolved free, DFAA, and combined fraction, DCAA). The concentrations of DOC in the subsurface water ranged from 130.2 to 407.7 μM C, with an average of 225.9±75.4 μM C, while those in the surface microlayer varied between 140.1 and 330.9 μM C, with an average of 217.8±56.8 μM C. The concentrations of chlorophyll a, DOC, TDCHO and THAA in the microlayer were, respectively correlated with their subsurface water concentrations, implying that there was a strong exchange effect between the microlayer and subsurface water. The concentrations of DOC and TDCHO were negatively correlated with salinity, respectively, indicating that water mixing might play an important role in controlling the distribution of DOC and TDCHO in the water column. Major constituents of DCAA and DFAA present in the study area were glycine, alanine, glutamic acid, serine and histidine. Principal component analysis (PCA) was applied to examine the complex compositional differences that existed among the sampling sites. Our results showed that DFAA had higher mole percentages of glycine, valine and serine in the microlayer than in the subsurface water, while DCAA tended to have higher mole percentages of glutamic acid, aspartic acid, threonine, arginine, alanine, tyrosine, phenylalanine and leucine in the microlayer. The yields of TDCHO and THAA exhibited similar trends between the microlayer and subsurface water. Carbohydrate species displayed significant enrichment in the microlayer, whereas the DFAA and DCAA exhibited non-uniform enrichment in the microlayer.

Subsurface clade of Geobacteraceae that predominates in a diversity of Fe(III)-reducing subsurface environments

Science.gov (United States)

Holmes, Dawn E.; O'Neil, Regina A.; Vrionis, Helen A.; N'Guessan, Lucie A.; Ortiz-Bernad, Irene; Larrahondo, Maria J.; Adams, Lorrie A.; Ward, Joy A.; Nicoll , Julie S.; Nevin, Kelly P.; Chavan, Milind A.; Johnson, Jessica P.; Long, Philip E.; Lovely, Derek R.

2007-01-01

There are distinct differences in the physiology of Geobacter species available in pure culture. Therefore, to understand the ecology of Geobacter species in subsurface environments, it is important to know which species predominate. Clone libraries were assembled with 16S rRNA genes and transcripts amplified from three subsurface environments in which Geobacter species are known to be important members of the microbial community: (1) a uranium-contaminated aquifer located in Rifle, CO, USA undergoing in situ bioremediation; (2) an acetate-impacted aquifer that serves as an analog for the long-term acetate amendments proposed for in situ uranium bioremediation and (3) a petroleum-contaminated aquifer in which Geobacter species play a role in the oxidation of aromatic hydrocarbons coupled with the reduction of Fe(III). The majority of Geobacteraceae 16S rRNA sequences found in these environments clustered in a phylogenetically coherent subsurface clade, which also contains a number of Geobacter species isolated from subsurface environments. Concatamers constructed with 43 Geobacter genes amplified from these sites also clustered within this subsurface clade. 16S rRNA transcript and gene sequences in the sediments and groundwater at the Rifle site were highly similar, suggesting that sampling groundwater via monitoring wells can recover the most active Geobacter species. These results suggest that further study of Geobacter species in the subsurface clade is necessary to accurately model the behavior of Geobacter species during subsurface bioremediation of metal and organic contaminants.

Mine Drainage Generation and Control Options.

Science.gov (United States)

Wei, Xinchao; Rodak, Carolyn M; Zhang, Shicheng; Han, Yuexin; Wolfe, F Andrew

2016-10-01

This review provides a snapshot of papers published in 2015 relevant to the topic of mine drainage generation and control options. The review is broken into 3 sections: Generation, Prediction and Prevention, and Treatment Options. The first section, mine drainage generation, focuses on the characterization of mine drainage and the environmental impacts. As such, it is broken into three subsections focused on microbiological characterization, physiochemical characterization, and environmental impacts. The second section of the review is divided into two subsections focused on either the prediction or prevention of acid mine drainage. The final section focuses on treatment options for mine drainage and waste sludge. The third section contains subsections on passive treatment, biological treatment, physiochemical treatment, and a new subsection on beneficial uses for mine drainage and treatment wastes.

The Serpentinite Subsurface Microbiome

Science.gov (United States)

Schrenk, M. O.; Nelson, B. Y.; Brazelton, W. J.

2011-12-01

Microbial habitats hosted in ultramafic rocks constitute substantial, globally-distributed portions of the subsurface biosphere, occurring both on the continents and beneath the seafloor. The aqueous alteration of ultramafics, in a process known as serpentinization, creates energy rich, high pH conditions, with low concentrations of inorganic carbon which place fundamental constraints upon microbial metabolism and physiology. Despite their importance, very few studies have attempted to directly access and quantify microbial activities and distributions in the serpentinite subsurface microbiome. We have initiated microbiological studies of subsurface seeps and rocks at three separate continental sites of serpentinization in Newfoundland, Italy, and California and compared these results to previous analyses of the Lost City field, near the Mid-Atlantic Ridge. In all cases, microbial cell densities in seep fluids are extremely low, ranging from approximately 100,000 to less than 1,000 cells per milliliter. Culture-independent analyses of 16S rRNA genes revealed low-diversity microbial communities related to Gram-positive Firmicutes and hydrogen-oxidizing bacteria. Interestingly, unlike Lost City, there has been little evidence for significant archaeal populations in the continental subsurface to date. Culturing studies at the sites yielded numerous alkaliphilic isolates on nutrient-rich agar and putative iron-reducing bacteria in anaerobic incubations, many of which are related to known alkaliphilic and subsurface isolates. Finally, metagenomic data reinforce the culturing results, indicating the presence of genes associated with organotrophy, hydrogen oxidation, and iron reduction in seep fluid samples. Our data provide insight into the lifestyles of serpentinite subsurface microbial populations and targets for future quantitative exploration using both biochemical and geochemical approaches.

The influence of flow-through saline gravel pit lakes on the hydrologic budget and hydrochemistry of a Mediterranean drainage basin

NARCIS (Netherlands)

Mollema, P.N.; Antonellini, Marco; Dinelli, Enrico; Greggio, Nicolas; Stuijfzand, Pieter

2015-01-01

Flow-through brackish gravel pit lakes near the Adriatic Coast of Emilia Romagna (Italy) in the Mediterranean have a large influence on the hydrologic budget of the watershed. Strong evaporation in combination with intense drainage of the low lying basins enhances groundwater inflow into the

Microbial activity in the terrestrial subsurface

International Nuclear Information System (INIS)

Kaiser, J.P.; Bollag, J.M.

1990-01-01

Little is known about the layers under the earth's crust. Only in recent years have techniques for sampling the deeper subsurface been developed to permit investigation of the subsurface environment. Prevailing conditions in the subsurface habitat such as nutrient availability, soil composition, redox potential, permeability and a variety of other factors can influence the microflora that flourish in a given environment. Microbial diversity varies between geological formations, but in general sandy soils support growth better than soils rich in clay. Bacteria predominate in subsurface sediments, while eukaryotes constitute only 1-2% of the microorganisms. Recent investigations revealed that most uncontaminated subsurface soils support the growth of aerobic heteroorganotrophic bacteria, but obviously anaerobic microorganisms also exist in the deeper subsurface habitat. The microorganisms residing below the surface of the earth are capable of degrading both natural and xenobiotic contaminants and can thereby adapt to growth under polluted conditions. (author) 4 tabs, 77 refs

Evaluation of Urban Drainage Infrastructure: New York City Case Study

Science.gov (United States)

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

Percutaneous catheter drainage of intrapulmonary fluid collection

International Nuclear Information System (INIS)

Park, E. D.; Kim, H. J.; Choi, P. Y.; Jung, S. H.

1994-01-01

With the success of percutaneous abdominal abscess drainage, attention is now being focused on the use of similar techniques in the thorax. We studied to evaluate the effect of percutaneous drainage in parenchymal fluid collections in the lungs. We performed percutaneous drainage of abscesses and other parenchymal fluid collections of the lungs in 15 patients. All of the procedures were performed under the fluoroscopic guidance with an 18-gauge Seldinger needle and coaxial technique with a 8-10F drainage catheter. Among 10 patients with lung abscess, 8 patients improved by percutaneous catheter drainage. In one patient, drainage was failed by the accidental withdrawal of the catheter before complete drainage. One patient died of sepsis 5 hours after the procedure. Among three patients with complicated bulla, successful drainage was done in two patients, but in the remaining patient, the procedure was failed. In one patient with intrapulmonary bronchogenic cyst, the drainage was not successful due to the thick internal contents. In one patient with traumatic hematoma, after the drainage of old blood clots, the signs of infection disappeared. Overally, of 14 patients excluding one who died, 11 patients improved with percutaneous catheter drainage and three patients did not. There were no major complications during and after the procedure. We conclude that percutaneous catheter drainage is effective and safe procedure for the treatment of parenchymal fluid collections of the lung in patients unresponsive to the medical treatment

Percutaneous catheter drainage of intrapulmonary fluid collection

Energy Technology Data Exchange (ETDEWEB)

Park, E. D.; Kim, H. J.; Choi, P. Y.; Jung, S. H. [Gyeongsang National University Hospital, Chinju (Korea, Republic of)

1994-01-15

With the success of percutaneous abdominal abscess drainage, attention is now being focused on the use of similar techniques in the thorax. We studied to evaluate the effect of percutaneous drainage in parenchymal fluid collections in the lungs. We performed percutaneous drainage of abscesses and other parenchymal fluid collections of the lungs in 15 patients. All of the procedures were performed under the fluoroscopic guidance with an 18-gauge Seldinger needle and coaxial technique with a 8-10F drainage catheter. Among 10 patients with lung abscess, 8 patients improved by percutaneous catheter drainage. In one patient, drainage was failed by the accidental withdrawal of the catheter before complete drainage. One patient died of sepsis 5 hours after the procedure. Among three patients with complicated bulla, successful drainage was done in two patients, but in the remaining patient, the procedure was failed. In one patient with intrapulmonary bronchogenic cyst, the drainage was not successful due to the thick internal contents. In one patient with traumatic hematoma, after the drainage of old blood clots, the signs of infection disappeared. Overally, of 14 patients excluding one who died, 11 patients improved with percutaneous catheter drainage and three patients did not. There were no major complications during and after the procedure. We conclude that percutaneous catheter drainage is effective and safe procedure for the treatment of parenchymal fluid collections of the lung in patients unresponsive to the medical treatment.

Impacts of sea-surface salinity in an eddy-resolving semi-global OGCM

Science.gov (United States)

Furue, Ryo; Takatama, Kohei; Sasaki, Hideharu; Schneider, Niklas; Nonaka, Masami; Taguchi, Bunmei

2018-02-01

To explore the impacts of sea-surface salinity (SSS) on the interannual variability of upper-ocean state, we compare two 10-year runs of an eddy-resolving ocean general circulation model (OGCM): in one, SSS is strongly restored toward a monthly climatology (World Ocean Atlas '98) and in the other, toward the SSS of a monthly gridded Argo product. The inclusion of the Argo SSS generally improves the interannual variability of the mixed layer depth; particularly so in the western tropical Pacific, where so-called "barrier layers" are reproduced when the Argo SSS is included. The upper-ocean subsurface salinity variability is also improved in the tropics and subtropics even below the mixed layer. To understand the reason for the latter improvement, we separate the salinity difference between the two runs into its "dynamical" and "spiciness" components. The dynamical component is dominated by small-scale noise due to the chaotic nature of mesoscale eddies. The spiciness difference indicates that as expected from the upper-ocean general circulation, SSS variability in the mixed layer is subducted into the thermocline in subtropics; this signal is generally advected downward, equatorward, and westward in the equator-side of the subtropical gyre. The SSS signal subducted in the subtropical North Pacific appears to enter the Indian Ocean through the Indonesian Throughflow, although this signal is weak and probably insignificant in our model.

Comparison of natural drainage group and negative drainage groups after total thyroidectomy: prospective randomized controlled study.

Science.gov (United States)

Woo, Seung Hoon; Kim, Jin Pyeong; Park, Jung Je; Shim, Hyun Seok; Lee, Sang Ha; Lee, Ho Joong; Won, Seong Jun; Son, Hee Young; Kim, Rock Bum; Son, Young-Ik

2013-01-01

The aim of this study was to compare a negative pressure drain with a natural drain in order to determine whether a negative pressure drainage tube causes an increase in the drainage volume. Sixty-two patients who underwent total thyroidectomy for papillary thyroid carcinoma (PTC) were enrolled in the study between March 2010 and August 2010 at Gyeongsang National University Hospital. The patients were prospectively and randomly assigned to two groups, a negative pressure drainage group (n=32) and natural drainage group (n=30). Every 3 hours, the volume of drainage was checked in the two groups until the tube was removed. The amount of drainage during the first 24 hours postoperatively was 41.68 ± 3.93 mL in the negative drain group and 25.3 ± 2.68 mL in the natural drain group (pdrain group was 35.19 ± 4.26 mL and natural drain groups 21.53 ± 2.90 mL (pdrain may increase the amount of drainage during the first 24-48 hours postoperatively. Therefore, it is not necessary to place a closed suction drain when only a total thyroidectomy is done.

Long-term monitoring of nitrate transport to drainage from three agricultural clayey till fields

Science.gov (United States)

Ernstsen, V.; Olsen, P.; Rosenbom, A. E.

2015-08-01

The application of nitrogen (N) fertilisers to crops grown on tile-drained fields is required to sustain most modern crop production, but it poses a risk to the aquatic environment since tile drains facilitate rapid transport pathways with no significant reduction in nitrate. To maintain the water quality of the aquatic environment and the provision of food from highly efficient agriculture in line with the EU's Water Framework Directive and Nitrates Directive, field-scale knowledge is essential for introducing water management actions on-field or off-field and producing an optimal differentiated N-regulation in future. This study strives to provide such knowledge by evaluating on 11 years of nitrate-N concentration measurements in drainage from three subsurface-drained clayey till fields (1.3-2.3 ha) representing approximately 71 % of the surface sediments in Denmark dominated by clay. The fields differ in their inherent hydrogeological field settings (e.g. soil-type, geology, climate, drainage and groundwater table) and the agricultural management of the fields (e.g. crop type, type of N fertilisers and agricultural practices). The evaluation revealed three types of clayey till fields characterised by: (i) low net precipitation, high concentration of nitrate-N, and short-term low intensity drainage at air temperatures often below 5 °C; (ii) medium net precipitation, medium concentration of nitrate-N, and short-term medium-intensity drainage at air temperatures often above 5 °C; and (iii) high net precipitation, low concentration of nitrate-N and long-term high intensity drainage at air temperatures above 5 °C. For each type, on-field water management actions, such as the selection of crop types and introduction of catch crops, appeared relevant, whereas off-field actions only seemed relevant for the latter two field types given the temperature-dependent reduction potential of nitrate off-field. This initial well-documented field-scale knowledge from fields

A daily salt balance model for stream salinity generation processes following partial clearing from forest to pasture

Directory of Open Access Journals (Sweden)

M. A. Bari

2006-01-01

Full Text Available We developed a coupled salt and water balance model to represent the stream salinity generation process following land use changes. The conceptual model consists of three main components with five stores: (i Dry, Wet and Subsurface Stores, (ii a saturated Groundwater Store and (iii a transient Stream zone Store. The Dry and Wet Stores represent the salt and water movement in the unsaturated zone and also the near-stream dynamic saturated areas, responsible for the generation of salt flux associated with surface runoff and interflow. The unsaturated Subsurface Store represents the salt bulge and the salt fluxes. The Groundwater Store comes into play when the groundwater level is at or above the stream invert and quantifies the salt fluxes to the Stream zone Store. In the stream zone module, we consider a 'free mixing' between the salt brought about by surface runoff, interflow and groundwater flow. Salt accumulation on the surface due to evaporation and its flushing by initial winter flow is also incorporated in the Stream zone Store. The salt balance model was calibrated sequentially following successful application of the water balance model. Initial salt stores were estimated from measured salt profile data. We incorporated two lumped parameters to represent the complex chemical processes like diffusion-dilution-dispersion and salt fluxes due to preferential flow. The model has performed very well in simulating stream salinity generation processes observed at Ernies and Lemon experimental catchments in south west of Western Australia. The simulated and observed stream salinity and salt loads compare very well throughout the study period with NSE of 0.7 and 0.4 for Ernies and Lemon catchment respectively. The model slightly over predicted annual stream salt load by 6.2% and 6.8%.

Drainage filter technologies to mitigate site-specific phosphorus losses in agricultural drainage discharge

DEFF Research Database (Denmark)

Kjærgaard, Charlotte; Heckrath, Goswin Johann; Canga, Eriona

in drainage. The Danish “SUPREME-TECH” project (2010-2016) (www.supreme-tech.dk) aims at providing the scientific basis for developing cost-effective filter technologies for P in agricultural drainage waters. The project studies different approaches of implementing filter technologies including drainage well....... Targeting high risk areas of P loss and applying site-specific measures promises to be a cost-efficient approach. The Danish Commission for Nature and Agriculture has, therefore, now called for a paradigm shift towards targeted, cost-efficient technologies to mitigate site-specific nutrient losses...... environmental threshold values (

Wetland Plant Guide for Assessing Habitat Impacts of Real-Time Salinity Management

Energy Technology Data Exchange (ETDEWEB)

Quinn, Nigel W.T.; Feldmann, Sara A.

2004-10-15

This wetland plant guide was developed to aid moist soil plant identification and to assist in the mapping of waterfowl and shorebird habitat in the Grassland Water District and surrounding wetland areas. The motivation for this habitat mapping project was a concern that real-time salinity management of wetland drainage might have long-term consequences for wildfowl habitat health--changes in wetland drawdown schedules might, over the long term, lead to increased soil salinity and other conditions unfavorable to propagation of the most desirable moist soil plants. Hence, the implementation of a program to monitor annual changes in the most common moist soil plants might serve as an index of habitat health and sustainability. Our review of the current scientific and popular literature failed to identify a good, comprehensive field guide that could be used to calibrate and verify high resolution remote sensing imagery, that we had started to use to develop maps of wetland moist soil plants in the Grassland Water District. Since completing the guide it has been used to conduct ground truthing field surveys using the California Native Plant Society methodology in 2004. Results of this survey and a previous wetland plant survey in 2003 are published in a companion LBNL publication summarizing 4 years of fieldwork to advance the science of real-time wetland salinity management.

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

Science.gov (United States)

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 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

Nitrogen patterns in subsurface waters of the Yzeron stream: effect of combined sewer overflows and subsurface-surface water mixing.

Science.gov (United States)

Aucour, A M; Bariac, T; Breil, P; Namour, P; Schmitt, L; Gnouma, R; Zuddas, P

2013-01-01

Urbanization subjects streams to increased nitrogen loads. Therefore studying nitrogen forms at the interface between urban stream and groundwater is important for water resource management. In this study we report results on water δ(18)O and nitrogen forms in subsurface waters of a stream (Yzeron, France). The sites studied were located upstream and downstream of combined sewer overflows (CSO) in a rural area and a periurban area, respectively. Water δ(18)O allowed us to follow the mixing of subsurface water with surface water. Dissolved organic nitrogen and organic carbon of fine sediment increased by 20-30% between rural and periurban subsurface waters in the cold season, under high flow. The highest nitrate levels were observed in rural subsurface waters in the cold season. The lowest nitrate levels were found in periurban subsurface waters in the warm season, under low flow. They corresponded to slow exchange of subsurface waters with channel water. Thus reduced exchange between surface and subsurface waters and organic-matter-rich input seemed to favor nitrate reduction in the downstream, periurban, subsurface waters impacted by CSO.

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

Science.gov (United States)

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

[Ascites drainage at home

NARCIS (Netherlands)

Lutjeboer, J.; Erkel, A.R. van; Hoeven, J.J.M. van der; Meer, R.W. van der

2015-01-01

Ascites can lead to many symptoms, and often occurs in patients with an end-stage malignancy such as ovarian, pancreatic, colonic, or gastric cancer. Intermittent ascites drainage is applied in these patients as a palliative measure. As frequent drainage is necessary, a subcutaneously tunnelled

Percutaneous transhepatic biliary drainage

International Nuclear Information System (INIS)

Park, Jae Hyung; Hong, Seong Mo; Han, Man Chung

1982-01-01

Percutaneous transhepatic biliary drainage was successfully made 20 times on 17 patients of obstructive jaundice for recent 1 year since June 1981 at Department of Radiology in Seoul National University Hospital. The causes of obstructive jaundice was CBD Ca in 13 cases, metastasis in 2 cases, pancreatic cancer in 1 case and CBD stone in 1 case. Percutaneous transhepatic biliary drainage is a relatively ease, safe and effective method which can be done after PTC by radiologist. It is expected that percutaneous transhepatic biliary drainage should be done as an essential procedure for transient permanent palliation of obstructive jaundice

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

Science.gov (United States)

Presser, Theresa S.; Schwarzbach, Steven E.

2008-01-01

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

Salinization Sources Along the Lower Jordan River Under Draught Conditions

Science.gov (United States)

Holtzman, R.; Shavit, U.; Segal, M.; Vengosh, A.; Farber, E.; Gavrieli, I.

2003-12-01

The Lower Jordan River, once a flowing freshwater river, is suffering from an ongoing reduction of discharge and water quality. The river flows between the Sea of Galilee and the Dead Sea, an aerial distance of about 105 Km. The severe reduction is caused by an excessive exploitation of its sources and diversion of sewage and agricultural drainage into the river. The extreme low flows and low water quality threaten the natural existence of the river and its potential use for agriculture. In spite of its importance, little research has been done in the river. The objectives of the study were to measure the discharge and water composition along the river and to evaluate the main sources that control its flow and chemical characteristics. The hypothesis of the study was that interaction with subsurface flows significantly affects the river flow and chemical composition. The research is based on a detailed field study, which included flow rate measurements in the river and its tributaries, water sampling and analysis and mass balance calculations of water and solutes. A portable Acoustic Doppler Velocimeter (ADV) was used to measure velocities and bathymetry at different locations across the river sections. Due to accessibility constraints, a floating traverse construction, which enables the ADV's deployment from one bank of the river, was developed. It was found that flow rate ranges between 500-1,100 L/s in northern (upstream) sections and 300-1,650 L/s in the south. This low discharge represents a significant reduction from historical values and is lower than recent published estimations. This research represents base flows only, as the measurements were done during a period of two consecutive draught years. Calculated mass balance of water flows in the northern sections shows that the subsurface source contributes to the river around 200-670 L/s (30-80% of the river flow). Calculations of solute balance show that the subsurface flows add 20-50% of the mass of

Hydrodynamic model of cells for designing systems of urban groundwater drainage

Science.gov (United States)

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 consid

The impact of informal irrigation practices on soil drainage condition, soil pollution and land suitability for agriculture in El Saf area of El Giza Governorate

Directory of Open Access Journals (Sweden)

Hanan E.M. El Azab

2015-12-01

Full Text Available The study area was selected in El Saf District of El Giza Governorate in Egypt, covering 21461.4 ha of Nile sediments and their outskirts of alluvial higher and lower terraces. The aim of this study was to assess the impact of informal irrigation practices on drainage deterioration, soil pollution and land suitability for agricultural use using the satellite LDCM data 2013. From the lower alluvial terraces (partly cultivated using wastewater, the drainage flows westward via descending slopes resulting in land deterioration in both the alluvial lower terraces and alluvial plain of River Nile. The drainage conditions are excessively drained soils in the alluvial upper terraces within soils of Typic Haplocalcids, sandy skeletal, but in the lower terraces it partly occurred within soils of Typic Torriorthents, sandy skeletal. Moderately well drained soils occurred in soils of Typic Torriorthents, sandy in the alluvial lower terraces, while in the alluvial plain of Nile sediments are Sodic Haplotorrerts, fine. Poorly drained soils in the lower alluvial terraces have soils of Typic Epiaquents, sandy associated with Sodic Psammaquents and Aquic Haplocalcids, coarse loamy, while in the alluvial plain of River Nile the soils are Halic Epiaquerts, fine. Very poorly drained soils (submerged areas are scattered spots in both the lower alluvial terraces and the alluvial plain. In the alluvial plain of River Nile, 1967.1 ha become not suitable for the traditional cultivated crops, while in the alluvial terraces 3251.0 ha are not suitable for the proposed cultivation of Jojoba plants. Heavy metals of Cadmium (Cd, Cobalt (Co, Lead (Pb and Nickel (Ni were added to the soil surface and sub-surface in the irrigated areas by wastewater in the lower alluvial terraces (moderately well drained soils, but Cd and Co exceeded the standards of permissible total concentrations in these soils. The same metals were added to soil sub-surface layers in the alluvial plain

Design and Hydrologic Performance of a Tile Drainage Treatment Wetland in Minnesota, USA

Directory of Open Access Journals (Sweden)

Christian Lenhart

2016-11-01

Full Text Available Treatment wetlands are increasingly needed to remove nitrate from agricultural drainage water to protect downstream waters, such as the Gulf of Mexico. This project sought to develop a new edge-of-field treatment wetland, designed to remove nitrate-nitrogen and enhance phosphorus removal by plant harvest and to monitor its effectiveness. A 0.10 ha wetland was designed and installed to treat subsurface drainage flow from farmland in southwestern Minnesota, USA, in 2013, and monitored for three years by recording flow, nitrate-nitrogen, total phosphorus (TP and soluble orthophosphorus (OP input to and output from the wetland. Prior to construction, a level-pool routing, mass balance approach with DRAINMOD flow inputs was used to predict nitrate removal efficiency. Nitrate load removal averaged 68% over three years, nearly matching model predictions. However, most denitrification occurred in the sub-soil of the wetland rather than in surface flow as predicted. Phosphorus removal was approximately 76% over three years, and phosphorus removed by plant uptake exceeded inflow mass in the third year. The edge-of-field design has potential as a cost-effective method to treat field outflows because agricultural landowners can adopt this treatment system with minimal loss of productive farmland. The wet-prairie vegetation and shallow depth also provide the opportunity to remove additional phosphorus via vegetative harvest.

Arterial Pulsations cannot Drive Intramural Periarterial Drainage: Significance for Aβ Drainage

Directory of Open Access Journals (Sweden)

Alexandra K. Diem

2017-08-01

Full Text Available Alzheimer's Disease (AD is the most common form of dementia and to date there is no cure or efficient prophylaxis. The cognitive decline correlates with the accumulation of amyloid-β (Aβ in the walls of capillaries and arteries. Our group has demonstrated that interstitial fluid and Aβ are eliminated from the brain along the basement membranes of capillaries and arteries, the intramural periarterial drainage (IPAD pathway. With advancing age and arteriosclerosis, the stiffness of arterial walls, this pathway fails in its function and Aβ accumulates in the walls of arteries. In this study we tested the hypothesis that arterial pulsations drive IPAD and that a valve mechanism ensures the net drainage in a direction opposite to that of the blood flow. This hypothesis was tested using a mathematical model of the drainage mechanism. We demonstrate firstly that arterial pulsations are not strong enough to produce drainage velocities comparable to experimental observations. Secondly, we demonstrate that a valve mechanism such as directional permeability of the IPAD pathway is necessary to achieve a net reverse flow. The mathematical simulation results are confirmed by assessing the pattern of IPAD in mice using pulse modulators, showing no significant alteration of IPAD. Our results indicate that forces other than the cardiac pulsations are responsible for efficient IPAD.

Drainage under increasing and changing requirements

NARCIS (Netherlands)

Schultz, E.; Zimmer, D.; Vlotman, W.F.

2007-01-01

This year the Working Group on Drainage of the International Commission on Irrigation and Drainage (ICID) celebrates its 25th anniversary. This paper reviews the development of drainage for three different agro-climatic zones, i.e. the temperate (humid), the arid/semi-arid and the humid/semi-humid

Insights into the diversity of eukaryotes in acid mine drainage biofilm communities.

Science.gov (United States)

Baker, Brett J; Tyson, Gene W; Goosherst, Lindsey; Banfield, Jillian F

2009-04-01

Microscopic eukaryotes are known to have important ecosystem functions, but their diversity in most environments remains vastly unexplored. Here we analyzed an 18S rRNA gene library from a subsurface iron- and sulfur-oxidizing microbial community growing in highly acidic (pH morphological characterization. Results revealed that the populations vary significantly with the habitat and no group is ubiquitous. Surprisingly, many of the eukaryotic lineages (with the exception of the APC) are closely related to neutrophiles, suggesting that they recently adapted to this extreme environment. Molecular analyses presented here confirm that the number of eukaryotic species associated with the acid mine drainage (AMD) communities is low. This finding is consistent with previous results showing a limited diversity of archaea, bacteria, and viruses in AMD environments and suggests that the environmental pressures and interplay between the members of these communities limit species diversity at all trophic levels.

Satellite data analysis for identification of groundwater salinization effects on coastal forest for monitoring purposes

Directory of Open Access Journals (Sweden)

M. Barbarella

2015-05-01

Full Text Available In the phreatic aquifer below the San Vitale pinewood (Ravenna, Italy, natural and anthropogenic land subsidence, the low topography and the artificial drainage system have led to widespread saltwater intrusion. Since changes in the groundwater concentration induce variations in the vegetation properties, recognizable by different spectral bands, a comparison between satellite images, ASTER and Worldview-2, was made using the NDVI. The aim was to identify the portions of pinewood affected by salinization through a procedure that could reduce the expensive and time consuming ground monitoring campaigns. Moreover, the Worldview-2 high resolutions were used to investigate the Thermophilic Deciduous Forest (TDF spectral behaviour without the influence of the allochthonous Pinus pinea species that is scattered throughout the pinewood. The NDVI, calculated with traditional bands, identified the same stressed areas using both satellite data. Instead, the new Red-Edge band of the Worldview-2 image allowed a greater correlation between NDVI and groundwater salinity.

Spatial Pattern of Soil Salinity in Area Around the Yellow River Delta and Its Seasonal Dynamics over a 3-year Period

Science.gov (United States)

Lai, J.; Ouyang, Z.

2017-12-01

Salt-affected land varies spatially and seasonally in terms of soil salinity. "Bohai Granary" is a newly proposed national-level program which was aimed to improve soil quality and mining grain production potential of the salt-affected land in east China. In this work, soil samples were monthly taken at 11 sites within Wudi county in the Yellow river delta. The spatial distribution pattern of soil salinity were investigated and its seasonal variation over 36 months were discussed. Our findings indicate that the vertical distribution type of soil salinity was bottom-accumulating in the near coastal area while its gradually turned into a type of surface-accumulating as the sampling site moving towards the inner land. The peak of the soil salinity along the soil profile alternately moved upwards and downwards during the growing seasons. However, there was no evidence for the increasing of the total salt amount within the upper 100cm of soil. Moreover, the salt was mostly accumulated in the upper soil (0-40cm) during the late spring and early summer season; and winter wheat was tend to be affected severely at this stage. Therefore, special field practices (e.g. regular irrigation to leach salt, good maintenance of drainage system) should be taken to minimize the threat of soil salinity.

Estimation of soil salinity in a drip irrigation system by using joint inversion of multicoil electromagnetic induction measurements

KAUST Repository

Jadoon, Khan Zaib

2015-05-12

Low frequency electromagnetic induction (EMI) is becoming a useful tool for soil characterization due to its fast measurement capability and sensitivity to soil moisture and salinity. In this research, a new EMI system (the CMD mini-Explorer) is used for subsurface characterization of soil salinity in a drip irrigation system via a joint inversion approach of multiconfiguration EMI measurements. EMI measurements were conducted across a farm where Acacia trees are irrigated with brackish water. In situ measurements of vertical bulk electrical conductivity (σb) were recorded in different pits along one of the transects to calibrate the EMI measurements and to compare with the modeled electrical conductivity (σ) obtained by the joint inversion of multiconfiguration EMI measurements. Estimates of σ were then converted into the universal standard of soil salinity measurement (i.e., electrical conductivity of a saturated soil paste extract – ECe). Soil apparent electrical conductivity (ECa) was repeatedly measured with the CMD mini-Explorer to investigate the temperature stability of the new system at a fixed location, where the ambient air temperature increased from 26°C to 46°C. Results indicate that the new EMI system is very stable in high temperature environments, especially above 40°C, where most other approaches give unstable measurements. In addition, the distribution pattern of soil salinity is well estimated quantitatively by the joint inversion of multicomponent EMI measurements. The approach of joint inversion of EMI measurements allows for the quantitative mapping of the soil salinity distribution pattern and can be utilized for the management of soil salinity.

Do laboratory salinity tolerances of freshwater animals correspond with their field salinity?

Energy Technology Data Exchange (ETDEWEB)

Kefford, Ben J.; Papas, Phil J.; Metzeling, Leon; Nugegoda, Dayanthi

2004-06-01

The degree to which laboratory derived measures of salinity tolerance reflect the field distributions of freshwater biota is uncertain. In this paper we compare laboratory-derived acute salinity tolerance (LC{sub 50} values) of freshwater macroinvertebrates (range 5.5-76 mS/cm) and fish (range 2.7-82 mS/cm) from southeastern Australia with the salinity from which they have been collected in the field. Only 4% of the macroinvertebrates were collected at salinity levels substantially higher than their 72-h LC{sub 50} obtained from directly transferring animals from low salinity water to the water they were tested (direct transfer LC{sub 50}). This LC{sub 50} value was correlated with the maximum salinity at which a species had been collected. For common macroinvertebrates, the maximum field salinity was approximated by the direct transfer 72-h LC{sub 50}. For adult freshwater fish, 21% of species were collected at salinities substantially greater than their acute direct transfer LC{sub 50} and there was a weak relationship between these two variables. Although there was a weak correlation between the direct transfer LC{sub 50} of early life stages of freshwater fish and the maximum field salinity, 58% of the field distribution were in higher than their LC{sub 50} values. In contrast, LC{sub 50} determined from experiments that acclimated adult fish to higher salinity (slow acclimation) provided a better indication of the field distribution: with only one fish species (7%) being in conflict with their maximum field salinity and a strong positive relationship between these variables. This study shows that laboratory measures of acute salinity tolerance can reflect the maximum salinity that macroinvertebrate and fish species inhabit and are consistent with some anecdotal observations from other studies. - Acute laboratory salinity tolerances relate to maximum salinity where organisms occur in nature.

Do laboratory salinity tolerances of freshwater animals correspond with their field salinity?

International Nuclear Information System (INIS)

Kefford, Ben J.; Papas, Phil J.; Metzeling, Leon; Nugegoda, Dayanthi

2004-01-01

The degree to which laboratory derived measures of salinity tolerance reflect the field distributions of freshwater biota is uncertain. In this paper we compare laboratory-derived acute salinity tolerance (LC 50 values) of freshwater macroinvertebrates (range 5.5-76 mS/cm) and fish (range 2.7-82 mS/cm) from southeastern Australia with the salinity from which they have been collected in the field. Only 4% of the macroinvertebrates were collected at salinity levels substantially higher than their 72-h LC 50 obtained from directly transferring animals from low salinity water to the water they were tested (direct transfer LC 50 ). This LC 50 value was correlated with the maximum salinity at which a species had been collected. For common macroinvertebrates, the maximum field salinity was approximated by the direct transfer 72-h LC 50 . For adult freshwater fish, 21% of species were collected at salinities substantially greater than their acute direct transfer LC 50 and there was a weak relationship between these two variables. Although there was a weak correlation between the direct transfer LC 50 of early life stages of freshwater fish and the maximum field salinity, 58% of the field distribution were in higher than their LC 50 values. In contrast, LC 50 determined from experiments that acclimated adult fish to higher salinity (slow acclimation) provided a better indication of the field distribution: with only one fish species (7%) being in conflict with their maximum field salinity and a strong positive relationship between these variables. This study shows that laboratory measures of acute salinity tolerance can reflect the maximum salinity that macroinvertebrate and fish species inhabit and are consistent with some anecdotal observations from other studies. - Acute laboratory salinity tolerances relate to maximum salinity where organisms occur in nature

Inventory of drainage wells and potential sources of contaminants to drainage-well inflow in Southwest Orlando, Orange County, Florida

Science.gov (United States)

Taylor, George Fred

1993-01-01

Potential sources of contaminants that could pose a threat to drainage-well inflow and to water in the Floridan aquifer system in southwest Orlando, Florida, were studied between October and December 1990. Drainage wells and public-supply wells were inventoried in a 14-square-mile area, and available data on land use and activities within each drainage well basin were tabulated. Three public-supply wells (tapping the Lower Floridan aquifer) and 38 drainage wells (open to the Upper Floridan aquifer) were located in 17 drainage basins within the study area. The primary sources of drainage-well inflow are lake overflow, street runoff, seepage from the surficial aquifer system, and process-wastewater disposal. Drainage-well inflow from a variety of ares, including resi- dential, commercial, undeveloped, paved, and industrial areas, are potential sources of con- taminants. The four general types of possible contaminants to drainage-well inflow are inorganic chemicals, organic compounds, turbidity, and microbiological contaminants. Potential contami- nant sources include plant nurseries, citrus groves, parking lots, plating companies, auto- motive repair shops, and most commonly, lake- overflow water. Drainage wells provide a pathway for contaminants to enter the Upper Floridan aquifer and there is a potential for contaminants to move downward from the Upper Floridan to the Lower Floridan aquifer.

Progress with the reclamation of saline soils in Peru

International Nuclear Information System (INIS)

Estrada, J.A.

1983-01-01

The present report is the result of five years' experimental work at the Costa Regional Development Institute (IRD-Costa), based in Canete, Lima, Peru, on the reclamation of land affected by salts and hence of seriously limited agricultural value (production lower than 50%). A reclamation method combining surface and at depth washing with artificial drainage of excess water has been tried out and a method of nutrition has been developed which is based on tonification of the seeds before sowing. The results obtained are rather encouraging, so the method looks very promising, especially as it also makes for considerable savings in fertilizers (some 20% less) and for better yields per unit area. Once the ionic behaviour of this method has been studied by means of radioisotopes a large contribution will have been made towards alleviating the problem of saline soils. (author)

Integrating experimental and numerical methods for a scenario-based quantitative assessment of subsurface energy storage options

Science.gov (United States)

Kabuth, Alina; Dahmke, Andreas; Hagrey, Said Attia al; Berta, Márton; Dörr, Cordula; Koproch, Nicolas; Köber, Ralf; Köhn, Daniel; Nolde, Michael; Tilmann Pfeiffer, Wolf; Popp, Steffi; Schwanebeck, Malte; Bauer, Sebastian

2016-04-01

second example, the option of seasonal hydrogen storage in a deep saline aquifer is considered. The induced thermal and hydraulic multiphase flow processes were simulated. Also, an integrative approach towards geophysical monitoring of gas presence was evaluated by synthetically applying these monitoring methods to the synthetic, however realistically defined numerical storage scenarios. Laboratory experiments provided parameterisations of geochemical effects caused by storage gas leakage into shallow aquifers in cases of sealing failure. Ultimately, the analysis of realistically defined scenarios of subsurface energy storage within the ANGUS+ project allows a quantification of the subsurface space claimed by a storage operation and its induced effects. Acknowledgments: This work is part of the ANGUS+ project (www.angusplus.de) and funded by the German Federal Ministry of Education and Research (BMBF) as part of the energy storage initiative "Energiespeicher".

Wound Drainage Culture (For Parents)

Science.gov (United States)

... Fitness Diseases & Conditions Infections Drugs & Alcohol School & Jobs Sports Expert Answers (Q&A) Staying Safe Videos for Educators Search English Español Wound Drainage Culture KidsHealth / For Parents / Wound Drainage Culture What's in ...

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

Science.gov (United States)

Malone, Robert W.; Nolan, Bernard T.; Ma, Liwang; Kanwar, Rameshwar S.; Pederson, Carl H.; Heilman, Philip

2014-01-01

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 transport to subsurface drain flow over a long term period under different tillage systems and application rates is not clear. Therefore, we calibrated and tested RZWQM using six years of data from Nashua, Iowa. In this experiment, atrazine was spring applied at 2.8 (1990–1992) and 0.6 kg/ha/yr (1993–1995) to two 0.4 ha plots with different tillage (till and no-till). The observed and simulated average annual flow weighted atrazine concentrations (FWAC) in subsurface drain flow from the no-till plot were 3.7 and 3.2 μg/L, respectively for the period with high atrazine application rates, and 0.8 and 0.9 μg/L, respectively for the period with low application rates. The 1990–1992 observed average annual FWAC difference between the no-till and tilled plot was 2.4 μg/L while the simulated difference was 2.1 μg/L. These observed and simulated differences for 1993–1995 were 0.1 and 0.1 μg/L, respectively. The Nash–Sutcliffe model performance statistic (EF) for cumulative atrazine flux to subsurface drain flow was 0.93 for the no-till plot testing years (1993–1995), which is comparable to other recent model tests. The value of EF is 1.0 when simulated data perfectly match observed data. The order of selected parameter sensitivity for RZWQM simulated FWAC was atrazine partition coefficient > number of macropores > atrazine half life in soil > soil hydraulic conductivity. Simulations from 1990 to 1995 with four different atrazine application rates applied at a constant rate throughout the simulation period showed concentrations in drain flow for the no-till plot to be twice those of the tilled plot. The differences were more pronounced in the early

Integrated geomechanical modelling for deep subsurface damage

NARCIS (Netherlands)

Wees, J.D. van; Orlic, B.; Zijl, W.; Jongerius, P.; Schreppers, G.J.; Hendriks, M.

2001-01-01

Government, E&P and mining industry increasingly demand fundamental insight and accurate predictions on subsurface and surface deformation and damage due to exploitation of subsurface natural resources, and subsurface storage of energy residues (e.g. CO2). At this moment deformation is difficult to

Flow in the unsaturated zone around a shallow subsurface radioactive waste trench: Interpretation of an infiltration–drainage test at the Chernobyl Pilot Site

International Nuclear Information System (INIS)

Van Meir, N.; Gaudet, J.P.; Phrommavanh, V.; Laurent, J.P.; Bugai, D.; Biron, R.

2012-01-01

This article describes an infiltration–drainage test carried out in the unsaturated zone (UZ) at the Chernobyl Pilot Site during October 2008; this is an international radioecology study site and is the subject of several papers in this special issue. The test has to be seen in the larger context of radionuclide transport from a waste trench. The conducted experiment consisted of infiltrating a layer of 9.5 cm of water in a circular area of 5.51 m 2 over 5 h. Its main objective was to create a larger range of water content values (and hence suction pressure values), not only at the top of the soil profile but also at greater depths, in this case up to 1.50 m. Observations of water content and suction pressure were carried out continuously at seven different depths during infiltration, drainage and during the return to natural conditions over a period of several months. This allowed deriving UZ parameter values with greater confidence than those derived from monitoring small natural water content changes over periods of years. The experiment also shows that a 1D model was incapable of correctly reproducing the observed water balance established on the central axis. A 2D axi-symmetric model was needed showing that lateral boundary effects have to be accounted for. This implies that small scale infiltrometer tests should be analysed in more than one dimension. It further became clear from the drainage curves that soil layering played a significant role and that in the present case hysteresis did not play a major role; i.e. the infiltration and drainage event can be reproduced with the same set of parameters and subsequent natural rain events can be reproduced well enough with two numerical models used for test interpretation, one is module oriented for reactive transfer, and the second with an automatic optimisation procedure. The robustness of the estimated parameter values, of the model discretisation and layer identification was tested over a 2-month period with

A comparison of sea surface salinity in the equatorial Pacific Ocean during the 1997-1998, 2012-2013, and 2014-2015 ENSO events

Science.gov (United States)

Corbett, Caroline M.; Subrahmanyam, Bulusu; Giese, Benjamin S.

2017-11-01

Sea surface salinity (SSS) variability during the 1997-1998 El Niño event and the failed 2012-2013 and 2014-2015 El Niño events is explored using a combination of observations and ocean reanalyses. Previously, studies have mainly focused on the sea surface temperature (SST) and sea surface height (SSH) variability. This analysis utilizes salinity data from Argo and the Simple Ocean Data Assimilation (SODA) reanalysis to examine the SSS variability. Advective processes and evaporation minus precipitation (E-P) variability is understood to influence SSS variability. Using surface wind, surface current, evaporation, and precipitation data, we analyze the causes for the observed SSS variability during each event. Barrier layer thickness and upper level salt content are also examined in connection to subsurface salinity variability. Both advective processes and E-P variability are important during the generation and onset of a successful El Niño, while a lack of one or both of these processes leads to a failed ENSO event.

Program overview: Subsurface science program

International Nuclear Information System (INIS)

1994-03-01

The OHER Subsurface Science Program is DOE's core basic research program concerned with subsoils and groundwater. These practices have resulted in contamination by mixtures of organic chemicals, inorganic chemicals, and radionuclides. A primary long-term goal is to provide a foundation of knowledge that will lead to the reduction of environmental risks and to cost-effective cleanup strategies. Since the Program was initiated in 1985, a substantial amount of research in hydrogeology, subsurface microbiology, and the geochemistry of organically complexed radionuclides has been completed, leading to a better understanding of contaminant transport in groundwater and to new insights into microbial distribution and function in the subsurface environments. The Subsurface Science Program focuses on achieving long-term scientific advances that will assist DOE in the following key areas: providing the scientific basis for innovative in situ remediation technologies that are based on a concept of decontamination through benign manipulation of natural systems; understanding the complex mechanisms and process interactions that occur in the subsurface; determining the influence of chemical and geochemical-microbial processes on co-contaminant mobility to reduce environmental risks; improving predictions of contaminant transport that draw on fundamental knowledge of contaminant behavior in the presence of physical and chemical heterogeneities to improve cleanup effectiveness and to predict environmental risks

The migration and monitoring of viscous NAPLs (coal tar and creosote) in the subsurface

Energy Technology Data Exchange (ETDEWEB)

Jackson, R. [Intera Engineering Ltd., Heidelberg, ON (Canada)

2009-07-01

The high viscosity of nonaqueous phase liquids (NAPLs) such as creosote and coal tar complicates efforts to monitor their mobility at contaminated sites. Viscous NAPLs can remain mobile for many decades after their application as a wood preservative, or after the closure of the facilities in which they were generated. NAPL-wet pathways in the subsurface can also lead to errors in residual saturation measurements. This abstract discussed issues related to creeping flow and the low seepage rates that are not accounted for using traditional measuring methods. Examples of creeping flow and the monitoring techniques used to assess it were presented for sites in British Columbia and Florida. The drainage of viscous NAPLs during water table declines was also considered, and a case study of a coal tar-removal procedures using polymer surfactant flooding was presented.

Pre-operative biliary drainage for obstructive jaundice

Science.gov (United States)

Fang, Yuan; Gurusamy, Kurinchi Selvan; Wang, Qin; Davidson, Brian R; Lin, He; Xie, Xiaodong; Wang, Chaohua

2014-01-01

Background Patients with obstructive jaundice have various pathophysiological changes that affect the liver, kidney, heart, and the immune system. There is considerable controversy as to whether temporary relief of biliary obstruction prior to major definitive surgery (pre-operative biliary drainage) is of any benefit to the patient. Objectives To assess the benefits and harms of pre-operative biliary drainage versus no pre-operative biliary drainage (direct surgery) in patients with obstructive jaundice (irrespective of a benign or malignant cause). Search methods We searched the Cochrane Hepato-Biliary Group Controlled Trials Register, Cochrane Central Register of Controlled Clinical Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, and Science Citation Index Expanded until February 2012. Selection criteria We included all randomised clinical trials comparing biliary drainage followed by surgery versus direct surgery, performed for obstructive jaundice, irrespective of the sample size, language, and publication status. Data collection and analysis Two authors independently assessed trials for inclusion and extracted data. We calculated the risk ratio (RR), rate ratio (RaR), or mean difference (MD) with 95% confidence intervals (CI) based on the available patient analyses. We assessed the risk of bias (systematic overestimation of benefit or systematic underestimation of harm) with components of the Cochrane risk of bias tool. We assessed the risk of play of chance (random errors) with trial sequential analysis. Main results We included six trials with 520 patients comparing pre-operative biliary drainage (265 patients) versus no pre-operative biliary drainage (255 patients). Four trials used percutaneous transhepatic biliary drainage and two trials used endoscopic sphincterotomy and stenting as the method of pre-operative biliary drainage. The risk of bias was high in all trials. The proportion of patients with malignant obstruction varied between 60

Enzymatic saccharification of dilute acid pretreated saline crops for fermentable sugar production

Energy Technology Data Exchange (ETDEWEB)

Zheng, Yi; Zhang, Ruihong [Biological and Agricultural Engineering Department, University of California, Davis One Shields Avenue, Davis, CA 95616 (United States); Pan, Zhongli [Biological and Agricultural Engineering Department, University of California, Davis One Shields Avenue, Davis, CA 95616 (United States); Processed Foods Research Unit, USDA-ARS-WRRC, 800 Buchanan Street, Albany, CA 94710 (United States); Wang, Donghai [Biological and Agricultural Engineering Department, Kansas State University, Manhattan, KS 66506 (United States)

2009-11-15

Four saline crops [athel (Tamarix aphylla L), eucalyptus (Eucalyptus camaldulensis), Jose Tall Wheatgrass (Agropyron elongatum), and Creeping Wild Ryegrass (Leymus triticoides)] that are used in farms for salt uptake from soil and drainage irrigation water have the potential for fuel ethanol production because they don't take a large number of arable lands. Dilute sulfuric acid pretreatment and enzymatic hydrolysis were conducted to select the optimum pretreatment conditions and the best saline crop for further enzymatic hydrolysis research. The optimum dilute acid pretreatment conditions included T = 165 C, t = 8 min, and sulfuric acid concentration 1.4% (w/w). Creeping Wild Ryegrass was decided to be the best saline crop. Solid loading, cellulase and {beta}-glucosidase concentrations had significant effects on the enzymatic hydrolysis of dilute acid pretreated Creeping Wild Ryegrass. Glucose concentration increased by 36 mg/mL and enzymatic digestibility decreased by 20% when the solid loading increased from 4 to 12%. With 8% solid loading, enzymatic digestibility increased by over 30% with the increase of cellulase concentration from 5 to 15 FPU/g-cellulose. Under given cellulase concentration of 15 FPU/g-cellulose, 60% increase of enzymatic digestibility of pretreated Creeping Wild Ryegrass was obtained with the increase of {beta}-glucosidase concentration up to 15 CBU/g-cellulose. With a high solid loading of 10%, fed-batch operation generated 12% and 18% higher enzymatic digestibility and glucose concentration, respectively, than batch process. (author)

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

Science.gov (United States)

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

Hydrochemical Characteristics and Formation of the Saline or Salty Springs in Eastern Sichuan Basin of China

Science.gov (United States)

Zhou, X.

2017-12-01

Saline or salty springs provide important information on the hydrogeochemical processes and hydrology within subsurface aquifers. More than 20 saline and salty springs occur in the core of anticlines in the eastern Sichuan Basin in southwestern China where the Lower and Middle Triassic carbonates outcrop. Water samples of 8 saline and salty springs (including one saline hot spring) were collected for analyses of the major and minor constituents, trace elements and stable oxygen and hydrogen isotopes. The TDS of the springs range from 4 to 83 g/L, and they are mainly of Cl-Na type. Sr, Ba and Li are the predominant trace elements. The δ2H and δ18O of the water samples indicate that they are of meteoric origin. The source of salinity of the springs originates from dissolution of minerals in the carbonates, including halite, gypsum, calcite and dolomite. The formation mechanism of the springs is that groundwater receives recharge from infiltration of precipitation, undergoes shallow or deep circulation in the core of the anticline and incongruent dissolution of the salt-bearing carbonates occurs, and emerges in the river valley in the form of springs with relatively high TDS. The 8 springs can be classified into 4 springs of shallow groundwater circulation and 4 springs of deep groundwater circulation according to the depth of groundwater circulation, 7 springs of normal temperature and 1 hot spring according to temperature. There are also 2 up-flow springs: the carbonate aquifers are overlain by relatively impervious sandstone and shale, groundwater may flows up to the ground surface through the local portion of the overlying aquiclude where fractures were relatively well developed, and emerges as an up-flow spring. Knowledge of the hydrochemical characteristics and the geneses of the saline and salty springs are of important significance for the utilization and preservation of the springs.

Advances in drainage: Selected works from the Tenth International Drainage Symposium

Science.gov (United States)

Strock, Jeffrey S.; Hay, Christopher; Helmers, Matthew; Nelson, Kelly A.; Sands, Gary R.; Skaggs, R. Wayne; Douglas-Mankin, Kyle R.

2018-01-01

This article introduces a special collection of fourteen articles accepted from among the 140 technical presentations, posters, and meeting papers presented at the 10th International ASABE Drainage Symposium. The symposium continued in the tradition of previous symposia that began in 1965 as a forum for presenting and assessing the progress of drainage research and implementation throughout the world. The articles in this collection address a wide range of topics grouped into five broad categories: (1) crop response, (2) design and management, (3) hydrology and scale, (4) modeling, and (5) water quality. The collection provides valuable information for scientists, engineers, planners, and others working on crop production, water quality, and water quantity issues affected by agricultural drainage. The collection also provides perspectives on the challenges of increasing agricultural production in a changing climate, with ever-greater attention to water quality and quantity concerns that will require integrated technical, economic, and social solutions.

[Ascites drainage at home].

Science.gov (United States)

Lutjeboer, Jacob; van Erkel, Arian R; van der Hoeven, J J M Koos; van der Meer, Rutger W

2015-01-01

Ascites can lead to many symptoms, and often occurs in patients with an end-stage malignancy such as ovarian, pancreatic, colonic, or gastric cancer. Intermittent ascites drainage is applied in these patients as a palliative measure. As frequent drainage is necessary, a subcutaneously tunnelled permanent ascites catheter is a good alternative for intermittent drainage. The patient can open - and then re-close - the catheter when abdominal pressure increases. We inserted 35 subcutaneously permanent ascites catheters in the course of the past 3.5 years in the Leiden University Medical Centre. The success rate was 100% and the complication risk was 2.9%. A subcutaneously tunnelled ascites catheter is an effective and safe palliative treatment for patients with end-stage malignant disease and suffering from ascites.

Mapping subsurface pathways for contaminant migration at a proposed low level waste disposal site using electromagnetic methods

International Nuclear Information System (INIS)

Pin, F.G.; Ketelle, R.H.

1984-01-01

Electromagnetic methods have been used to measure apparent terrain conductivity in the downstream portion of a watershed in which a waste disposal site is proposed. At that site, the pathways for waste migration in ground water are controlled by subsurface channels. The channels are identified using isocurves of measured apparent conductivity. Two upstream channel branches are found to merge into a single downstream channel which constitutes the main drainage path out of the watershed. The identification and mapping of the ground water pathways is an important contribution to the site characterization study and the pathways analysis. The direct applications of terrain conductivity mapping to the planning of the monitoring program, the hydrogeological testing, and the modeling study are demonstrated. 7 references, 4 figures

Failures and complications of thoracic drainage

Directory of Open Access Journals (Sweden)

Đorđević Ivana

2006-01-01

Full Text Available Background/Aim. Thoracic drainage is a surgical procedure for introducing a drain into the pleural space to drain its contents. Using this method, the pleura is discharged and set to the physiological state which enables the reexpansion of the lungs. The aim of the study was to prove that the use of modern principles and protocols of thoracic drainage significantly reduces the occurrence of failures and complications, rendering the treatment more efficient. Methods. The study included 967 patients treated by thoracic drainage within the period from January 1, 1989 to June 1, 2000. The studied patients were divided into 2 groups: group A of 463 patients treated in the period from January 1, 1989 to December 31, 1994 in whom 386 pleural drainage (83.36% were performed, and group B of 602 patients treated form January 1, 1995 to June 1, 2000 in whom 581 pleural drainage (96.51% were performed. The patients of the group A were drained using the classical standards of thoracic drainage by the general surgeons. The patients of the group B, however, were drained using the modern standards of thoracic drainage by the thoracic surgeons, and the general surgeons trained for this kind of the surgery. Results. The study showed that better results were achieved in the treatment of the patients from the group B. The total incidence of the failures and complications of thoracic drainage decreased from 36.52% (group A to 12.73% (group B. The mean length of hospitalization of the patients without complications in the group A was 19.5 days versus 10 days in the group B. The mean length of the treatment of the patients with failures and complications of the drainage in the group A was 33.5 days versus 17.5 days in the group B. Conclusion. The shorter length of hospitalization and the lower morbidity of the studied patients were considered to be the result of the correct treatment using modern principles of thoracic drainage, a suitable surgical technique, and a

SUBSURFACE REPOSITORY INTEGRATED CONTROL SYSTEM DESIGN

International Nuclear Information System (INIS)

C.J. Fernado

1998-01-01

The purpose of this document is to develop preliminary high-level functional and physical control system architectures for the proposed subsurface repository at Yucca Mountain. This document outlines overall control system concepts that encompass and integrate the many diverse systems being considered for use within the subsurface repository. This document presents integrated design concepts for monitoring and controlling the diverse set of subsurface operations. The subsurface repository design will be composed of a series of diverse systems that will be integrated to accomplish a set of overall functions and objectives. The subsurface repository contains several Instrumentation and Control (I andC) related systems including: waste emplacement systems, ventilation systems, communication systems, radiation monitoring systems, rail transportation systems, ground control monitoring systems, utility monitoring systems (electrical, lighting, water, compressed air, etc.), fire detection and protection systems, retrieval systems, and performance confirmation systems. Each of these systems involve some level of I andC and will typically be integrated over a data communication network. The subsurface I andC systems will also integrate with multiple surface-based site-wide systems such as emergency response, health physics, security and safeguards, communications, utilities and others. The scope and primary objectives of this analysis are to: (1) Identify preliminary system level functions and interface needs (Presented in the functional diagrams in Section 7.2). (2) Examine the overall system complexity and determine how and on what levels these control systems will be controlled and integrated (Presented in Section 7.2). (3) Develop a preliminary subsurface facility-wide design for an overall control system architecture, and depict this design by a series of control system functional block diagrams (Presented in Section 7.2). (4) Develop a series of physical architectures

SUBSURFACE REPOSITORY INTEGRATED CONTROL SYSTEM DESIGN

Energy Technology Data Exchange (ETDEWEB)

C.J. Fernado

1998-09-17

The purpose of this document is to develop preliminary high-level functional and physical control system architectures for the proposed subsurface repository at Yucca Mountain. This document outlines overall control system concepts that encompass and integrate the many diverse systems being considered for use within the subsurface repository. This document presents integrated design concepts for monitoring and controlling the diverse set of subsurface operations. The subsurface repository design will be composed of a series of diverse systems that will be integrated to accomplish a set of overall functions and objectives. The subsurface repository contains several Instrumentation and Control (I&C) related systems including: waste emplacement systems, ventilation systems, communication systems, radiation monitoring systems, rail transportation systems, ground control monitoring systems, utility monitoring systems (electrical, lighting, water, compressed air, etc.), fire detection and protection systems, retrieval systems, and performance confirmation systems. Each of these systems involve some level of I&C and will typically be integrated over a data communication network. The subsurface I&C systems will also integrate with multiple surface-based site-wide systems such as emergency response, health physics, security and safeguards, communications, utilities and others. The scope and primary objectives of this analysis are to: (1) Identify preliminary system level functions and interface needs (Presented in the functional diagrams in Section 7.2). (2) Examine the overall system complexity and determine how and on what levels these control systems will be controlled and integrated (Presented in Section 7.2). (3) Develop a preliminary subsurface facility-wide design for an overall control system architecture, and depict this design by a series of control system functional block diagrams (Presented in Section 7.2). (4) Develop a series of physical architectures that

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

Science.gov (United States)

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

Absolute Salinity, ''Density Salinity'' and the Reference-Composition Salinity Scale: present and future use in the seawater standard TEOS-10

Science.gov (United States)

Wright, D. G.; Pawlowicz, R.; McDougall, T. J.; Feistel, R.; Marion, G. M.

2011-01-01

Salinity plays a key role in the determination of the thermodynamic properties of seawater and the new TEOS-101 standard provides a consistent and effective approach to dealing with relationships between salinity and these thermodynamic properties. However, there are a number of practical issues that arise in the application of TEOS-10, both in terms of accuracy and scope, including its use in the reduction of field data and in numerical models. First, in the TEOS-10 formulation for IAPSO Standard Seawater, the Gibbs function takes the Reference Salinity as its salinity argument, denoted SR, which provides a measure of the mass fraction of dissolved material in solution based on the Reference Composition approximation for Standard Seawater. We discuss uncertainties in both the Reference Composition and the Reference-Composition Salinity Scale on which Reference Salinity is reported. The Reference Composition provides a much-needed fixed benchmark but modified reference states will inevitably be required to improve the representation of Standard Seawater for some studies. However, the Reference-Composition Salinity Scale should remain unaltered to provide a stable representation of salinity for use with the TEOS-10 Gibbs function and in climate change detection studies. Second, when composition anomalies are present in seawater, no single salinity variable can fully represent the influence of dissolved material on the thermodynamic properties of seawater. We consider three distinct representations of salinity that have been used in previous studies and discuss the connections and distinctions between them. One of these variables provides the most accurate representation of density possible as well as improvements over Reference Salinity for the determination of other thermodynamic properties. It is referred to as "Density Salinity" and is represented by the symbol SAdens; it stands out as the most appropriate representation of salinity for use in dynamical physical

Absolute Salinity, "Density Salinity" and the Reference-Composition Salinity Scale: present and future use in the seawater standard TEOS-10

Science.gov (United States)

Wright, D. G.; Pawlowicz, R.; McDougall, T. J.; Feistel, R.; Marion, G. M.

2010-08-01

Salinity plays a key role in the determination of the thermodynamic properties of seawater and the new TEOS-101 standard provides a consistent and effective approach to dealing with relationships between salinity and these thermodynamic properties. However, there are a number of practical issues that arise in the application of TEOS-10, both in terms of accuracy and scope, including its use in the reduction of field data and in numerical models. First, in the TEOS-10 formulation for IAPSO Standard Seawater, the Gibbs function takes the Reference Salinity as its salinity argument, denoted SR, which provides a measure of the mass fraction of dissolved material in solution based on the Reference Composition approximation for Standard Seawater. We discuss uncertainties in both the Reference Composition and the Reference-Composition Salinity Scale on which Reference Salinity is reported. The Reference Composition provides a much-needed fixed benchmark but modified reference states will inevitably be required to improve the representation of Standard Seawater for some studies. The Reference-Composition Salinity Scale should remain unaltered to provide a stable representation of salinity for use with the TEOS-10 Gibbs function and in climate change detection studies. Second, when composition anomalies are present in seawater, no single salinity variable can fully represent the influence of dissolved material on the thermodynamic properties of seawater. We consider three distinct representations of salinity that have been used in previous studies and discuss the connections and distinctions between them. One of these variables provides the most accurate representation of density possible as well as improvements over Reference Salinity for the determination of other thermodynamic properties. It is referred to as "Density Salinity" and is represented by the symbol SAdens; it stands out as the most appropriate representation of salinity for use in dynamical physical

Remote sensing for assessing the zone of benefit where deep drains improve productivity of land affected by shallow saline groundwater.

Science.gov (United States)

Kobryn, H T; Lantzke, R; Bell, R; Admiraal, R

2015-03-01

The installation of deep drains is an engineering approach to remediate land salinised by the influence of shallow groundwater. It is a costly treatment and its economic viability is, in part, dependent on the lateral extent to which the drain increases biological productivity by lowering water tables and soil salinity (referred to as the drains' zone of benefit). Such zones may be determined by assessing the biological productivity response of adjacent vegetation over time. We tested a multi-temporal satellite remote sensing method to analyse temporal and spatial changes in vegetation condition surrounding deep drainage sites at five locations in the Western Australian wheatbelt affected by dryland salinity-Morawa, Pithara, Beacon, Narembeen and Dumbleyung. Vegetation condition as a surrogate for biological productivity was assessed by Normalised Difference Vegetation Index (NDVI) during the peak growing season. Analysis was at the site scale within a 1000 m buffer zone from the drains. There was clear evidence of NDVI increasing with elevation, slope and distance from the drain. After accounting for elevation, slope and distance from the drain, there was a significant increase in NDVI across the five locations after installation of deep drains. Changes in NDVI after drainage were broadly consistent with measured changes at each site in groundwater levels after installation of the deep drains. However, this study assessed the lateral extent of benefit for biological productivity and gave a measure of the area of benefit along the entire length of the drain. The method demonstrated the utility of spring NDVI images for rapid and relatively simple assessment of the change in site condition after implementation of drainage, but approaches for further improvement of the procedure were identified. Copyright © 2014 Elsevier Ltd. All rights reserved.

Structure and evolution of the drainage system of a Himalayan debris-covered glacier, and its relationship with patterns of mass loss

Directory of Open Access Journals (Sweden)

D. I. Benn

2017-09-01

Full Text Available We provide the first synoptic view of the drainage system of a Himalayan debris-covered glacier and its evolution through time, based on speleological exploration and satellite image analysis of Ngozumpa Glacier, Nepal. The drainage system has several linked components: (1 a seasonal subglacial drainage system below the upper ablation zone; (2 supraglacial channels, allowing efficient meltwater transport across parts of the upper ablation zone; (3 sub-marginal channels, allowing long-distance transport of meltwater; (4 perched ponds, which intermittently store meltwater prior to evacuation via the englacial drainage system; (5 englacial cut-and-closure conduits, which may undergo repeated cycles of abandonment and reactivation; and (6 a "base-level" lake system (Spillway Lake dammed behind the terminal moraine. The distribution and relative importance of these elements has evolved through time, in response to sustained negative mass balance. The area occupied by perched ponds has expanded upglacier at the expense of supraglacial channels, and Spillway Lake has grown as more of the glacier surface ablates to base level. Subsurface processes play a governing role in creating, maintaining, and shutting down exposures of ice at the glacier surface, with a major impact on spatial patterns and rates of surface mass loss. Comparison of our results with observations on other glaciers indicate that englacial drainage systems play a key role in the response of debris-covered glaciers to sustained periods of negative mass balance.

SUBSURFACE CONSTRUCTION AND DEVELOPMENT ANALYSIS

International Nuclear Information System (INIS)

N.E. Kramer

1998-01-01

The purpose of this analysis is to identify appropriate construction methods and develop a feasible approach for construction and development of the repository subsurface facilities. The objective of this analysis is to support development of the subsurface repository layout for License Application (LA) design. The scope of the analysis for construction and development of the subsurface Repository facilities covers: (1) Excavation methods, including application of knowledge gained from construction of the Exploratory Studies Facility (ESF). (2) Muck removal from excavation headings to the surface. This task will examine ways of preventing interference with other subsurface construction activities. (3) The logistics and equipment for the construction and development rail haulage systems. (4) Impact of ground support installation on excavation and other construction activities. (5) Examination of how drift mapping will be accomplished. (6) Men and materials handling. (7) Installation and removal of construction utilities and ventilation systems. (8) Equipping and finishing of the emplacement drift mains and access ramps to fulfill waste emplacement operational needs. (9) Emplacement drift and access mains and ramps commissioning prior to handover for emplacement operations. (10) Examination of ways to structure the contracts for construction of the repository. (11) Discussion of different construction schemes and how to minimize the schedule risks implicit in those schemes. (12) Surface facilities needed for subsurface construction activities

Potential effects of alterations to the hydrologic system on the distribution of salinity in the Biscayne aquifer in Broward County, Florida

Science.gov (United States)

Hughes, Joseph D.; Sifuentes, Dorothy F.; White, Jeremy T.

2016-03-15

To address concerns about the effects of water-resource management practices and rising sea level on saltwater intrusion, the U.S. Geological Survey in cooperation with the Broward County Environmental Planning and Community Resilience Division, initiated a study to examine causes of saltwater intrusion and predict the effects of future alterations to the hydrologic system on salinity distribution in eastern Broward County, Florida. A three-dimensional, variable-density solute-transport model was calibrated to conditions from 1970 to 2012, the period for which data are most complete and reliable, and was used to simulate historical conditions from 1950 to 2012. These types of models are typically difficult to calibrate by matching to observed groundwater salinities because of spatial variability in aquifer properties that are unknown, and natural and anthropogenic processes that are complex and unknown; therefore, the primary goal was to reproduce major trends and locally generalized distributions of salinity in the Biscayne aquifer. The methods used in this study are relatively new, and results will provide transferable techniques for protecting groundwater resources and maximizing groundwater availability in coastal areas. The model was used to (1) evaluate the sensitivity of the salinity distribution in groundwater to sea-level rise and groundwater pumping, and (2) simulate the potential effects of increases in pumping, variable rates of sea-level rise, movement of a salinity control structure, and use of drainage recharge wells on the future distribution of salinity in the aquifer.

Acid drainage (AD) in nature and environmental impact of acid mine drainage (AMD) in Southern Tuscany

International Nuclear Information System (INIS)

Di Lella, Luigi Antonello; Protano, Giuseppe; Riccobono, Francesco

2005-01-01

Acid drainage (AD) is a natural process occurring locally at the Earth's surface. It consists in a substantial increase of acidity of surface waters as a result of chemical reactions occurring in the atmosphere (i.e. acid rain) or involving reactive phases (i.e. pyrite) present in the percolated medium. Acidic surface waters (usually pH < 4) can be produced by oxidation of sulphides (mainly pyrite and other iron sulphides) exposed to atmospheric oxygen, while human activities, such as mining, can greatly enhance this process. Acid drainage promoted by mining activities is called acid mine drainage (AMD) and is a primary source of environmental pollution and a world-wide problem in both active and abandoned mining areas. In fact, exposure of iron sulphides to oxidising conditions produces strongly acidic drainage waters rich in sulphate and a variety of heavy elements (i.e. As, Cd, Pb, Sb). Several occurrences of active acid mine drainage have been found in the Metalliferous Hills (southern Tuscany). The most important AMD phenomena were observed in the Fenice Capanne and Niccioleta mining areas

Impact of Variable-Density Flow on the Value-of-Information from Pressure and Concentration Data for Saline Aquifer Characterization

Science.gov (United States)

Yoon, S.; Williams, J. R.; Juanes, R.; Kang, P. K.

2017-12-01

Managed aquifer recharge (MAR) is becoming an important solution for ensuring sustainable water resources and mitigating saline water intrusion in coastal aquifers. Accurate estimates of hydrogeological parameters in subsurface flow and solute transport models are critical for making predictions and managing aquifer systems. In the presence of a density difference between the injected freshwater and ambient saline groundwater, the pressure field is coupled to the spatial distribution of salinity distribution, and therefore experiences transient changes. The variable-density effects can be quantified by a mixed convection ratio between two characteristic types of convection: free convection due to density contrast, and forced convection due to a hydraulic gradient. We analyze the variable-density effects on the value-of-information of pressure and concentration data for saline aquifer characterization. An ensemble Kalman filter is used to estimate permeability fields by assimilating the data, and the performance of the estimation is analyzed in terms of the accuracy and the uncertainty of estimated permeability fields and the predictability of arrival times of breakthrough curves in a realistic push-pull setting. This study demonstrates that: 1. Injecting fluids with the velocity that balances the two characteristic convections maximizes the value of data for saline aquifer characterization; 2. The variable-density effects on the value of data for the inverse estimation decrease as the permeability heterogeneity increases; 3. The advantage of joint inversion of pressure and concentration data decreases as the coupling effects between flow and transport increase.

Modeling subsurface stormflow initiation in low-relief landscapes

Science.gov (United States)

Hopp, Luisa; Vaché, Kellie B.; Rhett Jackson, C.; McDonnell, Jeffrey J.

2015-04-01

Shallow lateral subsurface flow as a runoff generating mechanism at the hillslope scale has mostly been studied in steeper terrain with typical hillside angles of 10 - 45 degrees. These studies have shown that subsurface stormflow is often initiated at the interface between a permeable upper soil layer and a lower conductivity impeding layer, e.g. a B horizon or bedrock. Many studies have identified thresholds of event size and soil moisture states that need to be exceeded before subsurface stormflow is initiated. However, subsurface stormflow generation on low-relief hillslopes has been much less studied. Here we present a modeling study that investigates the initiation of subsurface stormflow on low-relief hillslopes in the Upper Coastal Plain of South Carolina, USA. Hillslopes in this region typically have slope angles of 2-5 degrees. Topsoils are sandy, underlain by a low-conductivity sandy clay loam Bt horizon. Subsurface stormflow has only been intercepted occasionally in a 120 m long trench, and often subsurface flow was not well correlated with stream signals, suggesting a disconnect between subsurface flow on the hillslopes and stream flow. We therefore used a hydrologic model to better understand which conditions promote the initiation of subsurface flow in this landscape, addressing following questions: Is there a threshold event size and soil moisture state for producing lateral subsurface flow? What role does the spatial pattern of depth to the impeding clay layer play for subsurface stormflow dynamics? We reproduced a section of a hillslope, for which high-resolution topographic data and depth to clay measurements were available, in the hydrologic model HYDRUS-3D. Soil hydraulic parameters were based on experimentally-derived data. The threshold analysis was first performed using hourly climate data records for 2009-2010 from the study site to drive the simulation. For this period also trench measurements of subsurface flow were available. In addition

Percutaneous drainage of abscesses associated with biliary fistulae

International Nuclear Information System (INIS)

Berger, H.; Winter, T.; Pratschke, E.; Sauerbruch, T.; Klinikum Grosshadern, Muenchen; Klinikum Grosshadern, Muenchen

1989-01-01

33 abdominal abscesses associated with fistulae in 31 patients were treated by percutaneous drainage. 19 of these patients had had surgery immediately preceding the drainage. In 64% the percutaneous drainage led to a diagnosis of an internal fistula. Additional therapeutic measures, because of the fistula, were necessary in 45% (operation, biliary drainage, repositioning of catheter). The average duration of drainage was 29 days. 77% of those abscesses which could be drained were treated successfully. Mortality in the entire series was 19%. (orig.) [de

The side effects of nitrification inhibitors on leaching water and soil salinization in a field experiment

Energy Technology Data Exchange (ETDEWEB)

Diez, J. A.; Arauzo, M.; Hernaiz, P.; Sanz, A.

2010-07-01

In experiments carried out in greenhouses, some authors have shown that ammonium sulphate induces greater soil acidity and salinity than other sources of N. Moreover, nitrification inhibitors (NI) tend to cause ammonium to accumulate in soil by retarding its oxidation to nitrate. This accumulated ammonium would also have an effect on soil salinity. Consequently, the aim of this paper was to evaluate the soil and leaching water salinization effects associated with adding NI, dicyandiamide (DCD) and dimethylpyrazole-phosphate (DMPP) to ammonium sulphate nitrate (ASN) fertilizer. This experiment was carried out in the field with an irrigated maize crop. Drainage and Na concentration were measured during both seasons (2006 and 2007) and leached Na was determined. The treatments with NI (DCD and DMPP) were associated with greater Na concentrations in soil solutions and consequently higher rates of Na leaching (in 2007, ASN-DCD 1,292 kg Na ha{sup -}1, ASN-DMPP 1,019 kg Na ha{sup -}1). A treatment involving only ASN also increased the Na concentration in soil and the amount of Na leached in relation to the Control (in 2007, ASN 928 kg Na ha{sup -}1 and Control 587 kg Na ha{sup -}1). The increase in the ammonium concentration in the soil due to the NI treatments could have been the result of the displacement of Na ions from the soil exchange complex through a process which finally led to an increase in soil salinity. Treatments including ammonium fertilizer formulated with NI produced a greater degree of soil salinization due to the presence of ammonium from the fertilizer and accumulated ammonium from the nitrification inhibition. (Author) 31 refs.

SUBSURFACE EMPLACEMENT TRANSPORTATION SYSTEM

International Nuclear Information System (INIS)

Wilson, T.; Novotny, R.

1999-01-01

The objective of this analysis is to identify issues and criteria that apply to the design of the Subsurface Emplacement Transportation System (SET). The SET consists of the track used by the waste package handling equipment, the conductors and related equipment used to supply electrical power to that equipment, and the instrumentation and controls used to monitor and operate those track and power supply systems. Major considerations of this analysis include: (1) Operational life of the SET; (2) Geometric constraints on the track layout; (3) Operating loads on the track; (4) Environmentally induced loads on the track; (5) Power supply (electrification) requirements; and (6) Instrumentation and control requirements. This analysis will provide the basis for development of the system description document (SDD) for the SET. This analysis also defines the interfaces that need to be considered in the design of the SET. These interfaces include, but are not limited to, the following: (1) Waste handling building; (2) Monitored Geologic Repository (MGR) surface site layout; (3) Waste Emplacement System (WES); (4) Waste Retrieval System (WRS); (5) Ground Control System (GCS); (6) Ex-Container System (XCS); (7) Subsurface Electrical Distribution System (SED); (8) MGR Operations Monitoring and Control System (OMC); (9) Subsurface Facility System (SFS); (10) Subsurface Fire Protection System (SFR); (11) Performance Confirmation Emplacement Drift Monitoring System (PCM); and (12) Backfill Emplacement System (BES)

Subsurface Shielding Source Term Specification Calculation

International Nuclear Information System (INIS)

S.Su

2001-01-01

The purpose of this calculation is to establish appropriate and defensible waste-package radiation source terms for use in repository subsurface shielding design. This calculation supports the shielding design for the waste emplacement and retrieval system, and subsurface facility system. The objective is to identify the limiting waste package and specify its associated source terms including source strengths and energy spectra. Consistent with the Technical Work Plan for Subsurface Design Section FY 01 Work Activities (CRWMS M and O 2001, p. 15), the scope of work includes the following: (1) Review source terms generated by the Waste Package Department (WPD) for various waste forms and waste package types, and compile them for shielding-specific applications. (2) Determine acceptable waste package specific source terms for use in subsurface shielding design, using a reasonable and defensible methodology that is not unduly conservative. This calculation is associated with the engineering and design activity for the waste emplacement and retrieval system, and subsurface facility system. The technical work plan for this calculation is provided in CRWMS M and O 2001. Development and performance of this calculation conforms to the procedure, AP-3.12Q, Calculations

Radiologically-guided catheter drainage of intrathoracic abscesses and empyemas

International Nuclear Information System (INIS)

Berger, H.; Steiner, W.; Bergman, C.; Anthuber, M.; Dienemann, H.

1993-01-01

Radiologically guided percutaneous catheter drainage was used in 38 patients to treat pleural empyemas (35 patients) and pulmonary abscesses (3 patients). Drainage was successful in 85.7% of empyemas including 11 cases with fistulous communications. Three percutaneously drained pulmonary abscesses required subsequent lobectomy. One patient died during the drainage procedure due to sepsis. No major complications related to the drainage procedure were observed. Guided percutaneous drainage proved to be a safe and successful alternative to closed drainage of pleural fluid collections. (orig.)

Absolute Salinity, ''Density Salinity'' and the Reference-Composition Salinity Scale: present and future use in the seawater standard TEOS-10

Directory of Open Access Journals (Sweden)

D. G. Wright

2011-01-01

Full Text Available Salinity plays a key role in the determination of the thermodynamic properties of seawater and the new TEOS-10¹ standard provides a consistent and effective approach to dealing with relationships between salinity and these thermodynamic properties. However, there are a number of practical issues that arise in the application of TEOS-10, both in terms of accuracy and scope, including its use in the reduction of field data and in numerical models.

First, in the TEOS-10 formulation for IAPSO Standard Seawater, the Gibbs function takes the Reference Salinity as its salinity argument, denoted S_R, which provides a measure of the mass fraction of dissolved material in solution based on the Reference Composition approximation for Standard Seawater. We discuss uncertainties in both the Reference Composition and the Reference-Composition Salinity Scale on which Reference Salinity is reported. The Reference Composition provides a much-needed fixed benchmark but modified reference states will inevitably be required to improve the representation of Standard Seawater for some studies. However, the Reference-Composition Salinity Scale should remain unaltered to provide a stable representation of salinity for use with the TEOS-10 Gibbs function and in climate change detection studies.

Second, when composition anomalies are present in seawater, no single salinity variable can fully represent the influence of dissolved material on the thermodynamic properties of seawater. We consider three distinct representations of salinity that have been used in previous studies and discuss the connections and distinctions between them. One of these variables provides the most accurate representation of density possible as well as improvements over Reference Salinity for the determination of other thermodynamic properties. It is referred to as "Density Salinity" and is represented by the symbol

Percutaneous drainage of lung abscess

Energy Technology Data Exchange (ETDEWEB)

Ri, Jong Min; Kim, Yong Joo; Kang, Duk Sik [Kyung-Pook National University Hospital, Daegu (Korea, Republic of)

1992-05-15

Medical treatment using antibiotics and postural drainage has been widely adopted as a treatment method of pulmonary abscess, accompanied by surgical methods in cases intractable to drug therapy. However long-term therapy may be required, and the tolerance of organisms to antibiotics or other complications are apt to be encountered, during medical treatment. To shorten the convalescent period or to decrease the risk of invasive procedures, rather simple and relatively easy interventional techniques such as transbronchial or percutaneous catheter drainage have been successfully tried. We have performed 12 cases of percutaneous drainages of lung abscesses under fluoroscope guidance. This report is on the results of this procedure.

Percutaneous drainage of lung abscess

International Nuclear Information System (INIS)

Ri, Jong Min; Kim, Yong Joo; Kang, Duk Sik

1992-01-01

Medical treatment using antibiotics and postural drainage has been widely adopted as a treatment method of pulmonary abscess, accompanied by surgical methods in cases intractable to drug therapy. However long-term therapy may be required, and the tolerance of organisms to antibiotics or other complications are apt to be encountered, during medical treatment. To shorten the convalescent period or to decrease the risk of invasive procedures, rather simple and relatively easy interventional techniques such as transbronchial or percutaneous catheter drainage have been successfully tried. We have performed 12 cases of percutaneous drainages of lung abscesses under fluoroscope guidance. This report is on the results of this procedure

Percutaneous drainage of diverticular abscess: Adjunct to resection

International Nuclear Information System (INIS)

Mueller, P.R.; Saini, S.; Butch, R.J.; Simeone, J.F.; Rodkey, G.V.; Bousquet, J.C.; Ottinger, L.W.; Wittenberg, J.; Ferrucci, J.T. Jr.

1986-01-01

Traditional surgical management of acute diverticulitis with abscess may require a one-, two-, or three-stage procedure. Because of recent interest in CT diagnosis of diverticulitis, and novel access routes for interventional drainage of deep pelvic abscesses, the authors investigated the potential for converting complex two- and three-stage surgical procedures to simpler, safer one-stage colon resections by percutaneous drainage of the associated abscess. Of 23 patients with acute perforated diverticulitis who were referred for catheter drainage under radiologic guidance, successful catheter drainage and subsequent single-stage colon resection were carried out in 15. In three patients catheter drainage was unsuccessful and a multistage procedure was required. In three patients only percutaneous drainage was performed and operative intervention was omitted entirely

Geohydrologic reconnaissance of drainage wells in Florida

Science.gov (United States)

Kimrey, J.O.; Fayard, L.D.

1984-01-01

Drainage wells are used to inject surface waters directly into an aquifer, or shallow ground waters directly into a deeper aquifer, primarily by gravity. Such wells in Florida may be grouped into two broad types: (1) surface-water injection wells, and (2) interaquifer connector wells. Drainage wells of the first type are further categorized as either Floridan aquifer drainage wells or Biscayne aquifer drainage wells. Floridan aquifer drainage wells are commonly used to supplement drainage for urban areas in karst terranes of central and north Florida. Data are available for 25 wells in the Ocala, Live Oak, and Orlando areas that allow comparison of the quality of water samples from these Floridan aquifer drainage wells with allowable contaminant levels. Comparison indicates that maximum contaminant levels for turbidity, color, and iron, manganese, and lead concentrations are equaled or exceeded in some drainage-well samples, and relatively high counts for coliform bacteria are present in most wells. Biscayne aquifer drainage wells are used locally to dispose of stormwater runoff and other surplus water in southeast Florida, where large numbers of these wells have been permitted in Dade and Broward Counties. The majority of these wells are used to dispose of water from swimming pools or to dispose of heated water from air-conditioning units. The use of Biscayne aquifer drainage wells may have minimal effect on aquifer potability so long as injection of runoff and industrial wates is restricted to zones where chloride concentrations exceed 1,500 milligrams per liter. Interaquifer connector wells are used in the phosphate mining areas of Polk and Hillsborough Counties, to drain mines and recharge the Floridan aquifer. Water-quality data available from 13 connector wells indicate that samples from most of these wells exceed standards values for iron concentration and turbidity. One well yielded a highly mineralized water, and samples from 6 of the other 12 wells exceed

EFFECTIVENESS OF AUTOGENIC DRAINAGE VERSUS POSTURAL DRAINAGE ON OXYGEN SATURATION IN PATIENTS WITH CHRONIC BRONCHITIS WITH 15 MINUTES POST THERAPY

OpenAIRE

V. Kiran; Dr. Bhimasen .S; E. Mastanaiah; A. Thiruppathi

2014-01-01

Background: Patients with COPD will have more amount of secretions. To clear the secretions by using of different bronchial hygiene techniques like postural drainage and autogenic drainage technique, manual hyperventilation technique ,active cycle breathing technique .Hence in this study to compare the short-term effects of postural drainage with clapping (PD) and autogenic drainage (AD) on level of oxygen saturation in blood, and amount of sputum recovery. Methodology: The study was done ...

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

Science.gov (United States)

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.

Teaching of the subject "density difference caused by salinity", one of the reasons that plays role in the occurrence of currents in straits, seas and oceans by the use of a teaching material

Science.gov (United States)

Gumussoy, Verim

2015-04-01

Large masses of moving water in seas and oceans are called currents. Root causes of currents are steady winds that occur due to the global atmospheric system and the density differences caused by different heat and salinity levels of water masses. Different feeding and evaporation characteristics of seas and oceans result in salinity and density levels. As a result, subsurface currents occur in straits where seas with different salinity and density levels meet and in the nearby seas. The Bosporus in Istanbul where I live and the school I am working at is has these subsurface currents. In the Black Sea where the rivers the Danube, Dnieper, Don, Yesilirmak, Kizilirmak and Sakarya flow into and the evaporation level is less due to the latitude effect, salinity level is less compared to Marmara and Aegean Seas. As Marmara Sea has higher salt amount than Black Sea, there is a great density difference between these two seas. Marmara Sea has a higher concentration of salt and therefore a higher density than Black Sea. And this leads to occurrence of subsurface currents in the Bosporus. I get my students to carry out a small demonstration to help them understand the occurrence of ocean currents and currents in the seas and the Bosporus by the use of a material. We need very simple materials to carry out this demonstration. These are an aquarium, a bowl, water, salt, dye and a mixer. The demonstration is carried out as follows: we put water, salt and dye in the bowl and mix it well. The salt will increase the density of the water and the dye will help distinguish the salty water. Then we put tap water half way to the aquarium and pour the mixture in the bowl to the aquarium slowly. As a result, the colored salty water sinks down due to its higher density, setting an example of a subsurface current. Natural events occur in very long periods by great dynamic systems, making understanding of them difficult. It is important to use different kinds of materials that address to

Postoperative drainage in head and neck surgery.

Science.gov (United States)

Amir, Ida; Morar, Pradeep; Belloso, Antonio

2010-11-01

A major factor affecting patients' length of hospitalisation following head and neck surgery remains the use of surgical drains. The optimal time to remove these drains has not been well defined. A routine practice is to measure the drainage every 24 h and remove the drain when daily drainage falls below 25 ml. This study aims to determine whether drainage measurement at shorter intervals decreases the time to drain removal and hence the length of in-patient stays. A 6-month prospective observational study was performed. The inclusion criteria were patients who underwent head and neck surgery without neck dissection and had a closed suction drain inserted. Drainage rates were measured at 8-hourly intervals. Drains were removed when drainage-rate was ≤ 1 ml/h over an 8-h period. A total of 43 patients were evaluated. The highest drainage rate occurred in the first 8 postoperative hours and decreased significantly in the subsequent hours. The median drainage rates at 8, 16, 24, 32 and 40 postoperative hours were 3.375, 1, 0, 0 and 0 ml/h, respectively. Applying our new removal criteria of ≤ 1 ml/h drainage rate, the drains were removed in 22 (51%) patients at the 16th postoperative hour; 37 (86%) were removed by 24 h after operation. In comparison, only nine (20.9%) patients could potentially be discharged the day after surgery if previous criteria of ≤ 25 ml/24-h were used to decide on drain removal. Our 8-hourly drainage-rate monitoring has facilitated safe earlier discharge of an additional 28 (65%) patients on the day after surgery. This has led to improvement in patient care, better optimisation of hospital resources and resulted in positive economic implications to the department.

Recent experimental data may point to a greater role for osmotic pressures in the subsurface

Science.gov (United States)

Neuzil, C.E.; Provost, A.M.

2009-01-01

Uncertainty about the origin of anomalous fluid pressures in certain geologic settings has caused researchers to take a second look at osmosis, or flow driven by chemical potential differences, as a pressure‐generating process in the subsurface. Interest in geological osmosis has also increased because of an in situ experiment by Neuzil (2000) suggesting that Pierre Shale could generate large osmotic pressures when highly compacted. In the last few years, additional laboratory and in situ experiments have greatly increased the number of data on osmotic properties of argillaceous formations, but they have not been systematically examined. In this paper we compile these data and explore their implications for osmotic pressure generation in subsurface systems. Rather than base our analysis on osmotic efficiencies, which depend strongly on concentration, we calculated values of a quantity we term osmotic specific surface area (Aso) that, in principle, is a property of the porous medium only. The Aso values are consistent with a surprisingly broad spectrum of osmotic behavior in argillaceous formations, and all the formations tested exhibited at least a modest ability to generate osmotic pressure. It appears possible that under appropriate conditions some formations can be highly effective osmotic membranes able to generate osmotic pressures exceeding 30 MPa (3 km of head) at porosities as high as ∼0.1 and pressures exceeding 10 MPa at porosities as high as ∼0.2. These findings are difficult to reconcile with the lack of compelling field evidence for osmotic pressures, and we propose three explanations for the disparity: (1) Our analysis is flawed and argillaceous formations are less effective osmotic membranes than it suggests; (2) the necessary subsurface conditions, significant salinity differences within intact argillaceous formations, are rare; or (3) osmotic pressures are unlikely to be detected and are not recognized when encountered. The last possibility

Traditional Foley drainage systems--do they drain the bladder?

Science.gov (United States)

Garcia, Maurice M; Gulati, Shelly; Liepmann, Dorian; Stackhouse, G Bennett; Greene, Kirsten; Stoller, Marshall L

2007-01-01

Foley catheters are assumed to drain the bladder to completion. Drainage characteristics of Foley catheter systems are poorly understood. To investigate unrecognized retained urine with Foley catheter drainage systems, bladder volumes of hospitalized patients were measured with bladder scan ultrasound volumetrics. Additionally, an in vitro bench top mock bladder and urinary catheter system was developed to understand the etiology of such residual volumes. A novel drainage tube design that optimizes indwelling catheter drainage was also designed. Bedside bladder ultrasound volumetric studies were performed on patients hospitalized in ward and intensive care unit. If residual urine was identified the drainage tubing was manipulated to facilitate drainage. An ex vivo bladder-urinary catheter model was designed to measure flow rates and pressures within the drainage tubing of a traditional and a novel drainage tube system. A total of 75 patients in the intensive care unit underwent bladder ultrasound volumetrics. Mean residual volume was 96 ml (range 4 to 290). In 75 patients on the hospital ward mean residual volume was 136 ml (range 22 to 647). In the experimental model we found that for every 1 cm in curl height, obstruction pressure increased by 1 cm H2O within the artificial bladder. In contrast, the novel spiral-shaped drainage tube demonstrated rapid (0.5 cc per second), continuous and complete (100%) reservoir drainage in all trials. Traditional Foley catheter drainage systems evacuate the bladder suboptimally. Outflow obstruction is caused by air-locks that develop within curled redundant drainage tubing segments. The novel drainage tubing design eliminates gravity dependent curls and associated air-locks, optimizes flow, and minimizes residual bladder urine.

Component-based framework for subsurface simulations

International Nuclear Information System (INIS)

Palmer, B J; Fang, Yilin; Hammond, Glenn; Gurumoorthi, Vidhya

2007-01-01

Simulations in the subsurface environment represent a broad range of phenomena covering an equally broad range of scales. Developing modelling capabilities that can integrate models representing different phenomena acting at different scales present formidable challenges both from the algorithmic and computer science perspective. This paper will describe the development of an integrated framework that will be used to combine different models into a single simulation. Initial work has focused on creating two frameworks, one for performing smooth particle hydrodynamics (SPH) simulations of fluid systems, the other for performing grid-based continuum simulations of reactive subsurface flow. The SPH framework is based on a parallel code developed for doing pore scale simulations, the continuum grid-based framework is based on the STOMP (Subsurface Transport Over Multiple Phases) code developed at PNNL Future work will focus on combining the frameworks together to perform multiscale, multiphysics simulations of reactive subsurface flow

Radium Adsorption to Iron Bearing Minerals in Variable Salinity Waters

Science.gov (United States)

Chen, M.; Kocar, B. D.

2014-12-01

Radium is a common, naturally occurring radioactive metal found in many subsurface environments. Radium isotopes are a product of natural uranium and thorium decay, and are particularly abundant within groundwaters where minimal flux leads to accumulation within porewaters. Radium has been used as a natural tracer to estimate submarine groundwater discharge (SGD) [1], where the ratios of various radium isotopes are used to estimate total groundwater flux to and from the ocean [2]. Further, it represents a substantial hazard in waste water produced after hydraulic fracturing for natural gas extraction [3], resulting in a significant risk of environmental release and increased cost for water treatment or disposal. Adsorption to mineral surfaces represents a primary pathway of radium retention within subsurface environments. For SGD studies, it is important to understand adsorption processes to correctly estimate GW fluxes, while in hydraulic fracturing, radium adsorption to aquifer solids will mediate the activities of radium within produced water. While some studies of radium adsorption to various minerals have been performed [4], there is a limited understanding of the surface chemistry of radium adsorption, particularly to iron-bearing minerals such as pyrite, goethite and ferrihydrite. Accordingly, we present the results of sorption experiments of radium to a suite of iron-bearing minerals representative of those found within deep saline and near-surface (freshwater) aquifers, and evaluate impacts of varying salinity solutions through the use of artificial groundwater, seawater, and shale formation brine. Further, we explore the impacts of pyrite oxidation and ferrihydrite transformation to other iron-bearing secondary minerals on the retention of radium. This work lays the groundwork for further study of radium use as a tracer for SGD, as well as understanding mechanisms of radium retention and release from deep aquifer materials following hydraulic fracturing

SUBSURFACE VISUAL ALARM SYSTEM ANALYSIS

International Nuclear Information System (INIS)

D.W. Markman

2001-01-01

The ''Subsurface Fire Hazard Analysis'' (CRWMS M andO 1998, page 61), and the document, ''Title III Evaluation Report for the Surface and Subsurface Communication System'', (CRWMS M andO 1999a, pages 21 and 23), both indicate the installed communication system is adequate to support Exploratory Studies Facility (ESF) activities with the exception of the mine phone system for emergency notification purposes. They recommend the installation of a visual alarm system to supplement the page/party phone system The purpose of this analysis is to identify data communication highway design approaches, and provide justification for the selected or recommended alternatives for the data communication of the subsurface visual alarm system. This analysis is being prepared to document a basis for the design selection of the data communication method. This analysis will briefly describe existing data or voice communication or monitoring systems within the ESF, and look at how these may be revised or adapted to support the needed data highway of the subsurface visual alarm. system. The existing PLC communication system installed in subsurface is providing data communication for alcove No.5 ventilation fans, south portal ventilation fans, bulkhead doors and generator monitoring system. It is given that the data communication of the subsurface visual alarm system will be a digital based system. It is also given that it is most feasible to take advantage of existing systems and equipment and not consider an entirely new data communication system design and installation. The scope and primary objectives of this analysis are to: (1) Briefly review and describe existing available data communication highways or systems within the ESF. (2) Examine technical characteristics of an existing system to disqualify a design alternative is paramount in minimizing the number of and depth of a system review. (3) Apply general engineering design practices or criteria such as relative cost, and degree

Subsurface microbial habitats on Mars

Science.gov (United States)

Boston, P. J.; Mckay, C. P.

1991-01-01

We developed scenarios for shallow and deep subsurface cryptic niches for microbial life on Mars. Such habitats could have considerably prolonged the persistence of life on Mars as surface conditions became increasingly inhospitable. The scenarios rely on geothermal hot spots existing below the near or deep subsurface of Mars. Recent advances in the comparatively new field of deep subsurface microbiology have revealed previously unsuspected rich aerobic and anaerobic microbal communities far below the surface of the Earth. Such habitats, protected from the grim surface conditions on Mars, could receive warmth from below and maintain water in its liquid state. In addition, geothermally or volcanically reduced gases percolating from below through a microbiologically active zone could provide the reducing power needed for a closed or semi-closed microbial ecosystem to thrive.

Bedrock geologic map of the Spring Valley, West Plains, and parts of the Piedmont and Poplar Bluff 30'x60' quadrangles, Missouri, including the upper Current River and Eleven Point River drainage basins

Science.gov (United States)

Weary, David J.; Harrison, Richard W.; Orndorff, Randall C.; Weems, Robert E.; Schindler, J. Stephen; Repetski, John E.; Pierce, Herbert A.

2015-01-01

This map covers the drainage basins of the upper Current River and the Eleven Point River in the Ozark Plateaus physiographic province of southeastern Missouri. The two surface drainage basins are contiguous in their headwaters regions, but are separated in their lower reaches by the lower Black River basin in the southeast corner of the map area. Numerous dye-trace studies demonstrate that in the contiguous headwaters areas, groundwater flows from the Eleven Point River basin into the Current River basin. Much of the groundwater discharge of the Eleven Point River basin emanates from Big Spring, located on the Current River. This geologic map and cross sections were produced to help fulfill a need to understand the geologic framework of the region in which this subsurface flow occurs.

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

Science.gov (United States)

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.

Percutaneous catheter drainage of tuberculous psoas abscesses

International Nuclear Information System (INIS)

Pombo, F.; Martin-Egana, R.; Cela, A.; Diaz, J.L.; Linares-Mondejar, P.; Freire, M.

1993-01-01

Six patients with 7 tuberculous psoas or ilio-psoas abscesses were treated by CT-guided catheter drainage and chemotherapy. The abscesses (5 unilateral and 1 bilateral) were completely drained using a posterior or lateral approach. The abscess volume was 70 to 700 ml (mean 300 ml) and the duration of drainage 5 to 11 days (mean 7 days). Immediate local symptomatic improvement was achieved in all patients, and there were no procedural complications. CT follow-up at 3 to 9 months showed normalization in 5 patients, 2 of whom are still in medical therapy. One patient, who did not take the medication regularly, had a recurrent abscess requiring new catheter drainage after which the fluid collection disappeared. Percutaneous drainage represents an efficient and attractive alternative to surgical drainage as a supplement to medical therapy in the management of patients with large tuberculous psoas abscesses. (orig.)

Definition of the drainage filter problem

NARCIS (Netherlands)

Zaslavsky, D.

1977-01-01

It is common to consider the following: I. Retention of soil particles that may enter the drainage pipe and cause its clogging. For some sensitive structures it is important to prevent settlements due to soil transportation by drainage water.

Endoscopic ultrasound-guided transmural drainage of postoperative pancreatic collections.

Science.gov (United States)

Tilara, Amy; Gerdes, Hans; Allen, Peter; Jarnagin, William; Kingham, Peter; Fong, Yuman; DeMatteo, Ronald; D'Angelica, Michael; Schattner, Mark

2014-01-01

Pancreatic leak is a major cause of morbidity after pancreatectomy. Traditionally, peripancreatic fluid collections have been managed by percutaneous or operative drainage. Data for endoscopic ultrasound (EUS)-guided drainage of postoperative fluid collections are limited. Here we report on the safety, efficacy, and timing of EUS-guided drainage of postoperative peripancreatic collections. This is a retrospective review of 31 patients who underwent EUS-guided drainage of fluid collections after pancreatic resection. Technical success was defined as successful transgastric deployment of at least one double pigtail plastic stent. Clinical success was defined as resolution of the fluid collection on follow-up CT scan and resolution of symptoms. Early drainage was defined as initial transmural stent placement within 30 days after surgery. Endoscopic ultrasound-guided drainage was performed effectively with a technical success rate of 100%. Clinical success was achieved in 29 of 31 patients (93%). Nineteen of the 29 patients (65%) had complete resolution of their symptoms and collection with the first endoscopic procedure. Repeat drainage procedures, including some with necrosectomy, were required in the remaining 10 patients, with eventual resolution of collection and symptoms. Two patients who did not achieve durable clinical success required percutaneous drainage by interventional radiology. Seventeen (55%) of 31 patients had successful early drainage completed within 30 days of their operation. Endoscopic ultrasound-guided drainage of fluid collections after pancreatic resection is safe and effective. Early drainage (collections was not associated with increased complications in this series. Copyright © 2014 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

Subsurface contaminant transport from the liquid disposal area, CRNL

International Nuclear Information System (INIS)

Killey, R.W.D.; Munch, J.H.

1984-01-01

This report summarizes geologic, hydrogeologic and geochemical information obtained from a detailed study of the aquifer receiving contaminated waste-waters from the Chemical Pit. Geologically, the study area features wind-deposited sand overlying a continuous lacustrine clayey silt and a bouldery basal till. Medium to coarse sands locally found at the base of the sand sequence appear to represent stream channel deposits following a buried drainage course towards Perch Lake. These channel sands significantly influence groundwater flow; 3-dimensional models will be required to mathematically simulate the system. Based on the subsurface data, calculated groundwater residence times between the infiltration pit and points of discharge to surface into the East Swamp range from 4 to 22 months. The shortest observed residence time for a non-reactive radio-nuclide is 5 months. Tritium data confirm that contamination is confined to the sands, but show that within the sand aquifer there is considerable heterogeneity in the distribution and rates of groundwater flow. Samples of contaminated groundwaters collected during this study featured increased redox potentials, increased acidity, and minor increases in some major ions relative to local uncontaminated groundwater. Extensive oxidation of the sands in contaminated portions of the aquifer may reflect much greater chemical differences in plume groundwaters in the past

Thoracoscopic Surgery for Pneumothorax Following Outpatient Drainage Therapy.

Science.gov (United States)

Sano, Atsushi; Yotsumoto, Takuma

2017-10-20

We investigated the outcomes of surgery for pneumothorax following outpatient drainage therapy. We reviewed the records of 34 patients who underwent operations following outpatient drainage therapy with the Thoracic Vent at our hospital between December 2012 and September 2016. Indications for outpatient drainage therapy were pneumothorax without circulatory or respiratory failure and pleural effusion. Indications for surgical treatment were persistent air leakage and patient preference for surgery to prevent or reduce the incidence of recurrent pneumothorax. Intraoperatively, 9 of 34 cases showed loose adhesions around the Thoracic Vent, all of which were dissected bluntly. The preoperative drainage duration ranged from 5 to 13 days in patients with adhesions and from 3 to 19 days in those without adhesions, indicating no significant difference. The duration of preoperative drainage did not affect the incidence of adhesions. The operative duration ranged from 30 to 96 minutes in patients with adhesions and from 31 to 139 minutes in those without adhesions, also indicating no significant difference. Outpatient drainage therapy with the Thoracic Vent was useful for spontaneous pneumothorax patients who underwent surgery, and drainage for less than 3 weeks did not affect intraoperative or postoperative outcomes.

Foamed emulsion drainage: flow and trapping of drops

OpenAIRE

Schneider, Maxime; Zou, Ziqiang; Langevin, Dominique; Salonen, Anniina

2017-01-01

Foamed emulsions are ubiquitous in our daily life but the ageing of such systems is still poorly understood. In this study we investigate foam drainage and measure the evolution of the gas, liquid and oil volume fractions inside the foam. We evidence three regimes of ageing. During an initial period of fast drainage, both bubbles and drops are very mobile. As the foam stabilises drainage proceeds leading to a gradual decrease of the liquid fraction and slowing down of drainage. Clusters of oi...

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

OpenAIRE

Wiggers, Jimme K; Coelen, Robert JS; Rauws, Erik AJ; van Delden, Otto M; van Eijck, Casper HJ; de Jonge, Jeroen; Porte, Robert J; Buis, Carlijn I; Dejong, Cornelis HC; Molenaar, I Quintus; Besselink, Marc GH; Busch, Olivier RC; Dijkgraaf, Marcel GW; van Gulik, Thomas M

2015-01-01

Background 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, hemorr...

Percutaneous drainage treatment of primary liver abscesses

Energy Technology Data Exchange (ETDEWEB)

Berger, H.; Pratschke, E.; Berr, F.; Fink, U.

1989-02-01

28 primary liver abscesses, including 9 amoebic abscesses, in 24 patients were drained percutaneously. Indication for drainage in amoebic abscesses was imminent rupture and clinical symptoms as pleural effusion, lung atelectasis and pain. 95% of the primary abscesses were cured by percutaneous drainage and systemic antibiotic treatment. There was one recurrence of abscess, which was managed surgically. Reasons for drainage failure were: tumour necrosis and tumour perforation with secondary liver abscess.

Radiologic drainage of infected and noninfected thoracic fluid collections

International Nuclear Information System (INIS)

Van Sonnenberg, E.; Casola, G.; Stavas, J.; Neff, C.C.; Varney, R.A.; Wittich, G.R.; Dillard, J.; Christensen, R.A.; Friedman, P.J.

1987-01-01

Radiologically guided drainage of 100 thoracic fluid collections is described in this paper. Collections that underwent drainage include empyemas, lung abscesses, bronchopleural fistulas (BPFs), mediastinal abscesses, paracardial collections, bronchogenic cysts, sequestrations, lymphoceles, lymphangiomas, malignant effusions, and necrotic tumors. Catheters were placed for sclerotherapy in nine patients. Guidance modalities (in descending order of frequency) were CT, US, fluoroscopy, and MR. Inadequate thoracostomy tube drainage occurred in a third of the patients prior to radiologic drainage. Drainages were effective in 85% of cases, sparing surgery or another thoracostomy tube. Complications occurred in 7% of patients, most being minor and none requiring operation. Criteria for drainage of lung abscess and BPF will be emphasized, as will techniques and methods of follow-up

Tile Drainage Expansion Detection using Satellite Soil Moisture Dynamics

Science.gov (United States)

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

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

Directory of Open Access Journals (Sweden)

T. Guo

2018-01-01

Full Text Available 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

Bundle of measures for external cerebral ventricular drainage-associated ventriculitis.

Science.gov (United States)

Chatzi, Maria; Karvouniaris, Marios; Makris, Demosthenes; Tsimitrea, Eleni; Gatos, Charalampos; Tasiou, Anastasia; Mantzarlis, Kostas; Fountas, Kostas N; Zakynthinos, Epaminondas

2014-01-01

To assess the prevalence and outcome of external cerebral ventricular drainage-associated ventriculitis in neurocritical patients before and after the implementation of a bundle of external cerebral ventricular drainage-associated ventriculitis control measures. Clinical prospective case series. University Hospital of Larissa, Greece. Consecutive patients were recruited from the ICU of the hospital. Patient inclusion criteria included presence of external ventricular drainage and ICU stay more than 48 hours. The bundle of external cerebral ventricular drainage-associated ventriculitis control measures included 1) reeducation of ICU personnel on issues of infection control related to external cerebral ventricular drainage, 2) meticulous intraventricular catheter handling, 3) cerebrospinal fluid sampling only when clinically necessary, and 4) routine replacement of the drainage catheter on the seventh drainage day if the catheter was still necessary. The bundle was applied after an initial period (preintervention) where standard policy for external cerebral ventricular drainage-associated ventriculitis was established. External cerebral ventricular drainage-associated ventriculitis prevalence, external cerebral ventricular drainage-associated ventriculitis events per 1,000 drainage days (drain-associated infection rate), length of ICU stay, Glasgow Outcome Scale at 6 months, and risk factors for external cerebral ventricular drainage-associated ventriculitis. Eighty-two patients entered the study in the preintervention period and 57 patients during the intervention period. During the preintervention and intervention period, external cerebral ventricular drainage-associated ventriculitis prevalence was 28% and 10.5% (p = 0.02) and drain-associated infection rate was 18 and 7.1, respectively (p = 0.0001); mean (95% CI) length of ICU stay in patients who presented external cerebral ventricular drainage-associated ventriculitis was 44.4 days (36.4-52.4 d), whereas mean

Modes of supraglacial lake drainage and dynamic ice sheet response

Science.gov (United States)

Das, S. B.; Behn, M. D.; Joughin, I. R.

2011-12-01

We investigate modes of supraglacial lake drainage using geophysical, ground, and remote sensing observations over the western margin of the Greenland ice sheet. Lakes exhibit a characteristic life cycle defined by a pre-drainage, drainage, and post-drainage phase. In the pre-drainage phase winter snow fills pre-existing cracks and stream channels, efficiently blocking past drainage conduits. As temperatures increase in the spring, surface melting commences, initially saturating the snow pack and subsequently forming a surface network of streams that fills the lake basins. Basins continue to fill until lake drainage commences, which for individual lakes occurs at different times depending on the previous winter snow accumulation and summer temperatures. Three styles of drainage behavior have been observed: (1) no drainage, (2) slow drainage over the side into an adjacent pre-existing crack, and (3) rapid drainage through a new crack formed beneath the lake basin. Moreover, from year-to-year individual lakes exhibit different drainage behaviors. Lakes that drain slowly often utilize the same outflow channel for multiple years, creating dramatic canyons in the ice. Ultimately, these surface channels are advected out of the lake basin and a new channel forms. In the post-drainage phase, melt water continues to access the bed typically through a small conduit (e.g. moulin) formed near a local topographic minimum along the main drainage crack, draining the lake catchment throughout the remainder of the melt season. This melt water input to the bed leads to continued basal lubrication and enhanced ice flow compared to background velocities. Lakes that do not completely drain freeze over to form a surface ice layer that persists into the following year. Our results show that supraglacial lakes show a spectrum of drainage behaviors and that these styles of drainage lead to varying rates and timing of surface meltwater delivery to the bed resulting in different dynamic ice

Percutaneous drainage treatment of primary liver abscesses

International Nuclear Information System (INIS)

Berger, H.; Pratschke, E.; Berr, F.; Fink, U.; Klinikum Grosshadern, Muenchen; Klinikum Grosshadern, Muenchen

1989-01-01

28 primary liver abscesses, including 9 amoebic abscesses, in 24 patients were drained percutaneously. Indication for drainage in amoebic abscesses was imminent rupture and clinical symptoms as pleural effusion, lung atelectasis and pain. 95% of the primary abscesses were cured by percutaneous drainage and systemic antibiotic treatment. There was one recurrence of abscess, which was managed surgically. Reasons for drainage failure were: tumour necrosis and tumour perforation with secondary liver abscess. (orig.) [de

Endoscopic Ultrasound-Guided Biliary Drainage

International Nuclear Information System (INIS)

Artifon, Everson L.A.; Ferreira, Fla'vio C.; Sakai, Paulo

2012-01-01

To demonstrate a comprehensive review of published articles regarding endoscopic ultrasound (EUS)-guided biliary drainage. Review of studies regarding EUS-guided biliary drainage including case reports, case series and previous reviews. EUS-guided hepaticogastrostomy, coledochoduodenostomy and choledoantrostomy are advanced biliary and pancreatic endoscopy procedures, and together make up the echo-guided biliary drainage. Hepaticogastrostomy is indicated in cases of hilar obstruction, while the procedure of choice is the coledochoduodenostomy or choledochoantrostomy in distal lesions. Both procedures must be performed only after unsuccessful ERCPs. The indication of these procedures must be made under a multidisciplinary view while sharing information with the patient or legal guardian. Hepaticogastrostomy and coledochoduodenostomy or choledochoantrostomy are feasible when performed by endoscopists with expertise in biliopancreatic endoscopy. Advanced echo-endoscopy should currently be performed under a rigorous protocol in educational institutions.

Endoscopic Ultrasound-Guided Biliary Drainage

Energy Technology Data Exchange (ETDEWEB)

Artifon, Everson L.A.; Ferreira, Fla& #x27; vio C.; Sakai, Paulo [University of Saeo Paulo, Saeo Paulo (Brazil)

2012-02-15

To demonstrate a comprehensive review of published articles regarding endoscopic ultrasound (EUS)-guided biliary drainage. Review of studies regarding EUS-guided biliary drainage including case reports, case series and previous reviews. EUS-guided hepaticogastrostomy, coledochoduodenostomy and choledoantrostomy are advanced biliary and pancreatic endoscopy procedures, and together make up the echo-guided biliary drainage. Hepaticogastrostomy is indicated in cases of hilar obstruction, while the procedure of choice is the coledochoduodenostomy or choledochoantrostomy in distal lesions. Both procedures must be performed only after unsuccessful ERCPs. The indication of these procedures must be made under a multidisciplinary view while sharing information with the patient or legal guardian. Hepaticogastrostomy and coledochoduodenostomy or choledochoantrostomy are feasible when performed by endoscopists with expertise in biliopancreatic endoscopy. Advanced echo-endoscopy should currently be performed under a rigorous protocol in educational institutions.

Predictors of chest drainage complications in trauma patients

Directory of Open Access Journals (Sweden)

CECÍLIA ARAÚJO MENDES

2018-04-01

Full Text Available ABSTRACT Objective: to identify predictors of chest drainage complications in trauma patients attended at a University Hospital. Methods: we conducted a retrospective study of 68 patients submitted to thoracic drainage after trauma, in a one-year period. We analyzed gender, age, trauma mechanism, trauma indices, thoracic and associated lesions, environment in which the procedure was performed, drainage time, experience of the performer, complications and evolution. Results: the mean age of the patients was 35 years and the male gender was the most prevalent (89%. Blunt trauma was the most frequent, with 67% of cases, and of these, 50% were due to traffic accidents. The mean TRISS (Trauma and Injury Severity Score was 98, with a mortality rate of 1.4%. The most frequent thoracic and associated lesions were, respectively, rib fractures (51% and abdominal trauma (32%. The mean drainage time was 6.93 days, being higher in patients under mechanical ventilation (p=0.0163. The complication rate was 26.5%, mainly poor drain positioning (11.77%. Hospital drainage was performed in 89% of cases by doctors in the first year of specialization. Thoracic drainage performed in prehospital care presented nine times more chances of complications (p=0.0015. Conclusion: the predictors of post-trauma complications for chest drainage were a procedure performed in an adverse site and mechanical ventilation. The high rate of complications demonstrates the importance of protocols of care with the thoracic drainage.

Natural attenuation of antimony in mine drainage water

International Nuclear Information System (INIS)

Manaka, Mitsuo; Yanase, Nobuyuki; Sato, Tsutomu; Fukushi, Keisuke

2007-01-01

In this study, we investigated the natural attenuation of antimony (Sb) in the drainage water of an abandoned mine. Drainage water, waste rocks, and ocherous precipitates collected from the mine were investigated in terms of their mineralogy and chemistry. The chemistry of the drainage water was analyzed by measuring pH, oxidation-reduction potential (ORP), and electric conductivity on site as well as by inductively coupled plasma mass spectrometry and ion chromatography. As the drainage flowed downstream, the pH decreased rapidly from 7.05 to 3.26 and then increased slowly to 3.50. In a section where the pH increased, ocherous precipitates occur on a drainage water channel. We determined Sb levels in the drainage water, and the distribution of Sb in the mineral phases of waste rocks and precipitates was estimated by means of a sequential extraction procedure. The results of these investigations indicated that Sb, which is generated by the dissolution of stibnite (Sb 2 S 3 ) and secondary formed Sb minerals in waste rocks, was attenuated by iron-bearing ocherous precipitates, especially schwertmannite, that form over time in the drainage water. The Sb concentrations in the ocherous precipitates were up to 370 mg/kg, whereas the Sb concentrations in the drainage water downstream were below background levels (0.6 μg/L). Bulk distribution coefficients (K d ) for this Sb adsorption to the precipitates ranges up to at least 10 5 L/kg. (author)

Imaging near-subsurface subrosion structures and faults using SH-wave reflection seismics

Science.gov (United States)

Wadas, Sonja; Polom, Ulrich; Buness, Hermann; Krawczyk, Charlotte

2016-04-01

Subrosion is a term for underground leaching of soluble rocks and is a global phenomenon. It involves dissolution of evaporites due to the presence of unsaturated water, fractures and faults. Fractures and faults are pathways for water to circulate and to generate subsurface cavities. Depending on the leached material and the parameters of the generation process, especially the dissolution rate, different kinds of subrosion structures evolve in the subsurface. The two end members are collapse and depression structures. Subrosion is a natural process, but it can be enhanced by anthropogenic factors like manipulation of the aquifer system and groundwater flow and by e.g. extraction of saline water. The formation of sinkholes and depressions are a dangerous geohazard, especially if they occur in urban areas, which often leads to building and infrastructural damage and life-threatening situations. For this reason investigations of the processes that induce subrosion and a detailed analysis of the resulting structures are of importance. To develop a comprehensive model of near-subsurface subrosion structures, reflection seismics is one of the methods used by the Leibniz Institute for Applied Geophysics. The study area is located in the city of Bad Frankenhausen in northern Thuringia, Germany. Most of the geological underground of Thuringia is characterized by Permian deposits. Bad Frankenhausen is situated directly south of the Kyffhäuser mountain range at the Kyffhäuser Southern Margin Fault. This major fault is one of the main pathways for the circulating ground- and meteoric waters that leach the Permian deposits, especially the Leine-, Staßfurt- and Werra Formations. 2014 and 2015 eight shear wave reflection seismic profiles were carried out in the urban area of Bad Frankenhausen and three profiles in the countrified surroundings. Altogether ca. 3.6 km were surveyed using a landstreamer as receiver and an electro-dynamic vibrator as source. The surveys were

adequacy of drainage channels f drainage channels in a small

African Journals Online (AJOL)

eobe

The area upon which waterfalls and the netw through ... ls were determined using the rational model and manning's equation. A .... runoff, including roads, culverts and drainage systems. ... hence, detailed design information of the drain is.

Experimental and numerical analysis of the drainage of aluminium foams

International Nuclear Information System (INIS)

Brunke, O; Hamann, A; Cox, S J; Odenbach, S

2005-01-01

Drainage is one of the driving forces for the temporal instability of molten metal foams. For usual aqueous foams this phenomenon is well examined and understood on both the experimental and the theoretical side. The situation is different for metallic foams. Due to their opaque nature, the observation of drainage is only possible by either measuring the density distribution of solidified samples ex situ or by x-ray or neutron radioscopy. Up to now there exists just one theoretical study describing the drainage behaviour of metallic foams incorporating the drainage equation, the temperature dependence of the viscosity and thermal transport. This paper will present results on the drainage behaviour of aluminium foams grown by a powder-metallurgical production route. For this purpose an experiment which allows the observation of drainage in cylindrical metal foam columns has been developed. Experimental density profiles after different drainage times are measured ex situ and compared to numerical results of the standard drainage equation for aqueous foams. This first comparison between the density redistribution of metallic aluminium foams and numerical solutions shows that the standard drainage equation can be used to explain the drainage behaviour of metallic foams

Geochemical characterisation of seepage and drainage water quality from two sulphide mine tailings impoundments: Acid mine drainage versus neutral mine drainage

Science.gov (United States)

Heikkinen, P.M.; Raisanen, M.L.; Johnson, R.H.

2009-01-01

Seepage water and drainage water geochemistry (pH, EC, O2, redox, alkalinity, dissolved cations and trace metals, major anions, total element concentrations) were studied at two active sulphide mine tailings impoundments in Finland (the Hitura Ni mine and Luikonlahti Cu mine/talc processing plant). The data were used to assess the factors influencing tailings seepage quality and to identify constraints for water treatment. Changes in seepage water quality after equilibration with atmospheric conditions were evaluated based on geochemical modelling. At Luikonlahti, annual and seasonal changes were also studied. Seepage quality was largely influenced by the tailings mineralogy, and the serpentine-rich, low sulphide Hitura tailings produced neutral mine drainage with high Ni. In contrast, drainage from the high sulphide, multi-metal tailings of Luikonlahti represented typical acid mine drainage with elevated contents of Zn, Ni, Cu, and Co. Other factors affecting the seepage quality included weathering of the tailings along the seepage flow path, process water input, local hydrological settings, and structural changes in the tailings impoundment. Geochemical modelling showed that pH increased and some heavy metals were adsorbed to Fe precipitates after net alkaline waters equilibrated with the atmosphere. In the net acidic waters, pH decreased and no adsorption occurred. A combination of aerobic and anaerobic treatments is proposed for Hitura seepages to decrease the sulphate and metal loading. For Luikonlahti, prolonged monitoring of the seepage quality is suggested instead of treatment, since the water quality is still adjusting to recent modifications to the tailings impoundment.

Lower-Temperature Subsurface Layout and Ventilation Concepts

International Nuclear Information System (INIS)

Christine L. Linden; Edward G. Thomas

2001-01-01

This analysis combines work scope identified as subsurface facility (SSF) low temperature (LT) Facilities System and SSF LT Ventilation System in the Technical Work Plan for Subsurface Design Section FY 01 Work Activities (CRWMS M and O 2001b, pp. 6 and 7, and pp. 13 and 14). In accordance with this technical work plan (TWP), this analysis is performed using AP-3.10Q, Analyses and Models. It also incorporates the procedure AP-SI.1Q, Software Management. The purpose of this analysis is to develop an overall subsurface layout system and the overall ventilation system concepts that address a lower-temperature operating mode for the Monitored Geologic Repository (MGR). The objective of this analysis is to provide a technical design product that supports the lower-temperature operating mode concept for the revision of the system description documents and to provide a basis for the system description document design descriptions. The overall subsurface layout analysis develops and describes the overall subsurface layout, including performance confirmation facilities (also referred to as Test and Evaluation Facilities) for the Site Recommendation design. This analysis also incorporates current program directives for thermal management

Contribution of computed tomography on chest drainage guidance

International Nuclear Information System (INIS)

Douvlou, E.; Tzortzis, D.; Vlachou, I.; Petrocheilou, G.; Safarika, V.; Fragopoulou, L.; Stathopoulou, S.; Kokkinis, C.

2012-01-01

Full text: Introduction: Thoracic collections (encysted pleural, endopulmonary, mediastinal) are common findings in major trauma hospitals mainly in need of further treatment as drainage. Objectives and tasks: To evaluate the CT-guidance, as a method of choice for thoracic drainages. Material and methods: 35 CT-guided chest drainages were performed for diagnostic and therapeutic purpose in 33 patients, with a mean age of 62 years. Of the 35 drainages, 31 were encysted at the pleura, 3 of them were endopulmonary and 1 was in the mediastinum. During the procedure we used needles of 15cm long and 18-22 G diameter for small collections while for 'large' collections drainage catheters of 10-16 F were placed. Results: All the CT-guided drainages of the chest were successful. Of them, 7 were pleural effusion collections while 24 were exudate collections (18 inflammatory and 6 neoplastic) and all were developed in the lungs or the mediastinum. In all the cases that a catheter was placed, full removal of the collections was achieved leading to a remarkable improvement of the patient's condition. Non-significant pneumothorax and tiny endopulmonary bleeding were the complications that occurred. Conclusion: CT-guided drainage of thoracic collections is an accurate and secure procedure and achieves high diagnostic and therapeutic results

Saline groundwater in crystalline bedrock

International Nuclear Information System (INIS)

Lampen, P.

1992-11-01

The State-of-art report describes research made on deep saline groundwaters and brines found in crystalline bedrock, mainly in site studies for nuclear waste disposal. The occurrence, definitions and classifications of saline groundwaters are reviewed with a special emphasis on the different theories concerning the origins of saline groundwaters. Studies of the saline groundwaters in Finland and Sweden have been reviewed more thoroughly. Also the mixing of different bodies of groundwaters, observations of the contact of saline groundwaters and permafrost, and the geochemical modelling of saline groundwaters as well as the future trends of research have been discussed. (orig.)

Biogenic Carbon on Mars: A Subsurface Chauvinistic Viewpoint

Science.gov (United States)

Onstott, T. C.; Lau, C. Y. M.; Magnabosco, C.; Harris, R.; Chen, Y.; Slater, G.; Sherwood Lollar, B.; Kieft, T. L.; van Heerden, E.; Borgonie, G.; Dong, H.

2015-12-01

A review of 150 publications on the subsurface microbiology of the continental subsurface provides ~1,400 measurements of cellular abundances down to 4,800 meter depth. These data suggest that the continental subsurface biomass is comprised of ~1016-17 grams of carbon, which is higher than the most recent estimates of ~1015 grams of carbon (1 Gt) for the marine deep biosphere. If life developed early in Martian history and Mars sustained an active hydrological cycle during its first 500 million years, then is it possible that Mars could have developed a subsurface biomass of comparable size to that of Earth? Such a biomass would comprise a much larger fraction of the total known Martian carbon budget than does the subsurface biomass on Earth. More importantly could a remnant of this subsurface biosphere survive to the present day? To determine how sustainable subsurface life could be in isolation from the surface we have been studying subsurface fracture fluids from the Precambrian Shields in South Africa and Canada. In these environments the energetically efficient and deeply rooted acetyl-CoA pathway for carbon fixation plays a central role for chemolithoautotrophic primary producers that form the base of the biomass pyramid. These primary producers appear to be sustained indefinitely by H2 generated through serpentinization and radiolytic reactions. Carbon isotope data suggest that in some subsurface locations a much larger population of secondary consumers are sustained by the primary production of biogenic CH4 from a much smaller population of methanogens. These inverted biomass and energy pyramids sustained by the cycling of CH4 could have been and could still be active on Mars. The C and H isotopic signatures of Martian CH4 remain key tools in identifying potential signatures of an extant Martian biosphere. Based upon our results to date cavity ring-down spectroscopic technologies provide an option for making these measurements on future rover missions.

Subsurface contaminants focus area

International Nuclear Information System (INIS)

1996-08-01

The US Department of Enregy (DOE) Subsurface Contaminants Focus Area is developing technologies to address environmental problems associated with hazardous and radioactive contaminants in soil and groundwater that exist throughout the DOE complex, including radionuclides, heavy metals; and dense non-aqueous phase liquids (DNAPLs). More than 5,700 known DOE groundwater plumes have contaminated over 600 billion gallons of water and 200 million cubic meters of soil. Migration of these plumes threatens local and regional water sources, and in some cases has already adversely impacted off-site rsources. In addition, the Subsurface Contaminants Focus Area is responsible for supplying technologies for the remediation of numerous landfills at DOE facilities. These landfills are estimated to contain over 3 million cubic meters of radioactive and hazardous buried Technology developed within this specialty area will provide efective methods to contain contaminant plumes and new or alternative technologies for development of in situ technologies to minimize waste disposal costs and potential worker exposure by treating plumes in place. While addressing contaminant plumes emanating from DOE landfills, the Subsurface Contaminants Focus Area is also working to develop new or alternative technologies for the in situ stabilization, and nonintrusive characterization of these disposal sites

Subsurface contaminants focus area

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-08-01

The US Department of Enregy (DOE) Subsurface Contaminants Focus Area is developing technologies to address environmental problems associated with hazardous and radioactive contaminants in soil and groundwater that exist throughout the DOE complex, including radionuclides, heavy metals; and dense non-aqueous phase liquids (DNAPLs). More than 5,700 known DOE groundwater plumes have contaminated over 600 billion gallons of water and 200 million cubic meters of soil. Migration of these plumes threatens local and regional water sources, and in some cases has already adversely impacted off-site rsources. In addition, the Subsurface Contaminants Focus Area is responsible for supplying technologies for the remediation of numerous landfills at DOE facilities. These landfills are estimated to contain over 3 million cubic meters of radioactive and hazardous buried Technology developed within this specialty area will provide efective methods to contain contaminant plumes and new or alternative technologies for development of in situ technologies to minimize waste disposal costs and potential worker exposure by treating plumes in place. While addressing contaminant plumes emanating from DOE landfills, the Subsurface Contaminants Focus Area is also working to develop new or alternative technologies for the in situ stabilization, and nonintrusive characterization of these disposal sites.

[Endoscopic ultrasound guided rendezvous for biliary drainage].

Science.gov (United States)

Knudsen, Marie Høxbro; Vilmann, Peter; Hassan, Hazem; Karstensen, John Gésdal

2015-04-27

Endoscopic retrograde cholangiography (ERCP) is currently standard treatment for biliary drainage. Endoscopic ultrasound guided rendezvous (EUS-RV) is a novel method to overcome an unsuccessful biliary drainage procedure. Under endoscopic ultrasound guidance a guidewire is passed via a needle from the stomach or duodenum to the common bile duct and from there on to the duodenum enabling ERCP. With a relatively high rate of success EUS-RV should be considered as an alternative to biliary drainage and surgical intervention.

Subsurface Science Program Bibliography, 1985--1992

International Nuclear Information System (INIS)

1992-08-01

The Subsurface Science Program sponsors long-term basic research on (1) the fundamental physical, chemical, and biological mechanisms that control the reactivity, mobilization, stability, and transport of chemical mixtures in subsoils and ground water; (2) hydrogeology, including the hydraulic, microbiological, and geochemical properties of the vadose and saturated zones that control contaminant mobility and stability, including predictive modeling of coupled hydraulic-geochemical-microbial processes; and (3) the microbiology of deep sediments and ground water. TWs research, focused as it is on the natural subsurface environments that are most significantly affected by the more than 40 years of waste generation and disposal at DOE sites, is making important contributions to cleanup of DOE sites. Past DOE waste-disposal practices have resulted in subsurface contamination at DOE sites by unique combinations of radioactive materials and organic and inorganic chemicals (including heavy metals), which make site cleanup particularly difficult. The long- term (10- to 30-year) goal of the Subsurface Science Program is to provide a foundation of fundamental knowledge that can be used to reduce environmental risks and to provide a sound scientific basis for cost-effective cleanup strategies. The Subsurface Science Program is organized into nine interdisciplinary subprograms, or areas of basic research emphasis. The subprograms currently cover the areas of Co-Contaminant Chemistry, Colloids/Biocolloids, Multiphase Fluid Flow, Biodegradation/ Microbial Physiology, Deep Microbiology, Coupled Processes, Field-Scale (Natural Heterogeneity and Scale), and Environmental Science Research Center

Fate of Brine Applied to Unpaved Roads at a Radioactive Waste Subsurface Disposal Area

International Nuclear Information System (INIS)

Larry C. Hull; Carolyn W. Bishop

2004-01-01

Between 1984 and 1993, MgCl 2 brine was used to suppress dust on unpaved roads at a radioactive waste subsurface disposal area. Because Cl - might enhance corrosion of buried metals in the waste, we investigated the distribution and fate of Cl - in the vadose zone using pore water samples collected from suction lysimeters and soluble salt concentrations extracted from sediment samples. The Cl/Br mass ratio and the total dissolved Cl - concentration of pore water show that brine contamination occurs primarily within 13 m of treated roads, but can extend as much as 30 m laterally in near-surface sedimentary deposits. Within the deep vadose zone, which consists of interlayered basalt lava flows and sedimentary interbeds, brine has moved up to 110 m laterally. This lateral migration suggests formation of perched water and horizontal transport during periods of high recharge. In a few locations, brine migrated to depths of 67 m within 3 to 5 yr. Elevated Cl - concentrations were found to depths of 2 m in roadbed material. In drainage ditches along roads, where runoff accumulates and recharge of surface water is high, Cl - was flushed from the sediments in 3 to 4 yr. In areas of lower recharge, Cl - remained in the sediments after 5 yr. Vertical brine movement is directly related to surface recharge through sediments. The distribution of Cl - in pore water and sediments is consistent with estimates of vadose zone residence times and spatial distribution of surface water recharge from other investigations at the subsurface disposal area

THE ESTIMATION OF SOME CHANGES OF SOIL PHYSICAL STATE UNDER THE EFFECT OF LAND RECLAMATION TECHNOLOGIES, IN THE CONDITION OF SUBSURFACE DRAINAGE IN BAIA-MOLDOVA DEPPRESSION

Directory of Open Access Journals (Sweden)

V. Moca

2006-10-01

Full Text Available In the pedo-climatic conditions of Suceava County that extends on a total surface of 855 300 ha, the balance of agricultural land affected by humidity excess with temporar or permanent character is differenciated from south to north and from east to west, between 30 % till 40%, which means almost 100 000 ha. On these soils with underground water or pluvial excess hydro ameliorative drainage systems have been installed, associated to a complex agroameliorative works. For long effect estimation of the underground drainage asociated with the agropedoameliorative works upon the some physical and hydrophysical characteristics, there were analyzed the soil and the environment conditions from Baia field. For this reason, we analyzed the agrophysical conditions for luvisol albic pseudogleic (SRCS-1980, respectively luvosol albic stagnic-glosic (SRTS-2003 albic luvosoil drained and cultivated, after a period of 28 years (1978-2006 use. The obtained data regarding to te water balance and the evolution of the major physical properties of soil, under the influence of drainage and amelioration works, put into evidence in the first stage (1978-1986 a general improvement of the aerohidrycal state and physical-chemical conditioning. In the next two experimental cycles of 10 years each, have been noticed a increased of compaction degree of soil drained and cultivated on 0-30 cm depth, from weak loose to moderately compaction depending on the remanence of the reclamation technologies.

Subsurface probing

International Nuclear Information System (INIS)

Lytle, R.J.

1978-01-01

Imaging techniques that can be used to translate seismic and electromagnetic wave signals into visual representation are briefly discussed. The application of these techniques is illustrated on the example of determining the subsurface structure of a proposed power plant. Imaging makes the wave signals intelligible to the non-geologists. R and D work needed in this area are tabulated

A steady state solution for ditch drainage problem with special reference to seepage face and unsaturated zone flow contribution: Derivation of a new drainage spacing eqaution

Science.gov (United States)

Yousfi, Ammar; Mechergui, Mohammed

2016-04-01

al. (2001). In this work, a novel solution based on theoretical approach will be adapted to incorporate both the seepage face and the unsaturated zone flow contribution for solving ditch drained aquifers problems. This problem will be tackled on the basis of the approximate 2D solution given by Castro-Orgaz et al. (2012). This given solution yields the generalized water table profile function with a suitable boundary condition to be determined and provides a modified DF theory which permits as an outcome the analytical determination of the seepage face. To assess the ability of the developed equation for water-table estimations, the obtained results were compared with numerical solutions to the 2-D problem under different conditions. It is shown that results are in fair agreement and thus the resulting model can be used for designing ditch drainage systems. With respect to drainage design, the spacings calculated with the newly derived equation are compared with those computed from the DF theory. It is shown that the effect of the unsaturated zone flow contribution is limited to sandy soils and The calculated maximum increase in drain spacing is about 30%. Keywords: subsurface ditch drainage; unsaturated zone; seepage face; water-table, ditch spacing equation

Percutaneous transhepatic biliary drainage for hilar cholangiocarcinoma

International Nuclear Information System (INIS)

Qian Xiaojun; Jin Wenhui; Dai Dingke; Yu Ping; Gao Kun; Zhai Renyou

2007-01-01

Objective: To evaluate the effect of PTBD in treating malignant biliary obstruction caused by hilar cholangiocarcinoma. Methods: We retrospectively analyzed the data of 103 patients(M:62,F:41)with malignant obstructive jaundice caused by hilar cholangiocarcinoma. After taking percutaneous transhepatic cholangiography, metallic stent or plastic external catheter or external-internal catheter for drainage was deployed and then followed up was undertaken with clinical and radiographic evaluation and laboratory. examination. Results: All patients went though PTBD successfully (100%). According to Bismuth classification, all 103 cases consisted of I type(N=30), II type (N=30), III type (N=26) and IV type (N=17). Thirty-nine cases were placed with 47 stents and 64 eases with drainage tubes. 4 cases installed two stems for bilateral drainage, 2 cases installed two stents because of long segmental strictures with stent in stent, 1 case was placed with three stents, and 3 cases installed stent and plastic catheter together. Sixty-four cases received plastic catheters in this series, 35 cases installed two or more catheters for bilateral drainage, 28 cases installed external and internal drainage catheters, 12 eases installed external drainage catheters, and 24 eases installed both of them. There were 17 patients involving incorporative infection before procedure, 13 cases cured after procedure, and 15 new patients got inflammation after procedure. 13 cases showed increase of amylase (from May, 2004), 8 eases had bloody bile drainage and 1 case with pyloric obstruction. Total serum bilirubin reduced from (386 ± 162) μmol/L to (161 ± 117) μmol/L, (P<0.01) short term curative effect was related with the type of hilar cholangiocarcinoma. The survival time was 186 days(median), and 1, 3, 6, 12 month survival rate were 89.9%, 75.3%, 59.6%, 16.9%, respectively. Conclusion: Percutaneous transhepatic bile drainage is a safe and effective palliative therapy of malignant

Subsurface transport program: Research summary

International Nuclear Information System (INIS)

1987-01-01

DOE's research program in subsurface transport is designed to provide a base of fundamental scientific information so that the geochemical, hydrological, and biological mechanisms that contribute to the transport and long term fate of energy related contaminants in subsurface ecosystems can be understood. Understanding the physical and chemical mechanisms that control the transport of single and co-contaminants is the underlying concern of the program. Particular attention is given to interdisciplinary research and to geosphere-biosphere interactions. The scientific results of the program will contribute to resolving Departmental questions related to the disposal of energy-producing and defense wastes. The background papers prepared in support of this document contain additional information on the relevance of the research in the long term to energy-producing technologies. Detailed scientific plans and other research documents are available for high priority research areas, for example, in subsurface transport of organic chemicals and mixtures and in the microbiology of deep aquifers. 5 figs., 1 tab

Foamed emulsion drainage: flow and trapping of drops.

Science.gov (United States)

Schneider, Maxime; Zou, Ziqiang; Langevin, Dominique; Salonen, Anniina

2017-06-07

Foamed emulsions are ubiquitous in our daily life but the ageing of such systems is still poorly understood. In this study we investigate foam drainage and measure the evolution of the gas, liquid and oil volume fractions inside the foam. We evidence three regimes of ageing. During an initial period of fast drainage, both bubbles and drops are very mobile. As the foam stabilises drainage proceeds leading to a gradual decrease of the liquid fraction and slowing down of drainage. Clusters of oil drops are less sheared, their dynamic viscosity increases and drainage slows down even further, until the drops become blocked. At this point the oil fraction starts to increase in the continuous phase. The foam ageing leads to an increase of the capillary pressure until the oil acts as an antifoaming agent and the foam collapses.

Priority Scale of Drainage Rehabilitation of Cilacap City

Science.gov (United States)

Rudiono, Jatmiko

2018-03-01

Characteristics of physical condition of Cilacap City is relatively flat and low to sea level (approximately 6 m above sea level). In the event of a relatively heavy rainfall resulting in inundation at several locations. The problem of inundation is a serious problem if there is in a dense residential area or occurs in publicly-used infrastructure, such as roads and settlements. These problems require improved management of which include how to plan a sustainable urban drainage system and environmentally friendly. The development of Cilacap City is increasing rapidly, this causes drainage system based on the Drainage Masterplan Cilacap made in 2006 has not been able to accommodate rain water, so, it is necessary to evaluate the drainage masterplan for subsequent rehabilitation. Priority scale rehabilitation of the drainage sections as a guideline is an urgent need of rehabilitation in the next time period.

MSTS - Multiphase Subsurface Transport Simulator theory manual

International Nuclear Information System (INIS)

White, M.D.; Nichols, W.E.

1993-05-01

The US Department of Energy, through the Yucca Mountain Site Characterization Project Office, has designated the Yucca Mountain site in Nevada for detailed study as the candidate US geologic repository for spent nuclear fuel and high-level radioactive waste. Site characterization will determine the suitability of the Yucca Mountain site for the potential waste repository. If the site is determined suitable, subsequent studies and characterization will be conducted to obtain authorization from the Nuclear Regulatory Commission to construct the potential waste repository. A principal component of the characterization and licensing processes involves numerically predicting the thermal and hydrologic response of the subsurface environment of the Yucca Mountain site to the potential repository over a 10,000-year period. The thermal and hydrologic response of the subsurface environment to the repository is anticipated to include complex processes of countercurrent vapor and liquid migration, multiple-phase heat transfer, multiple-phase transport, and geochemical reactions. Numerical simulators based on mathematical descriptions of these subsurface phenomena are required to make numerical predictions of the thermal and hydrologic response of the Yucca Mountain subsurface environment The engineering simulator called the Multiphase Subsurface Transport Simulator (MSTS) was developed at the request of the Yucca Mountain Site Characterization Project Office to produce numerical predictions of subsurface flow and transport phenomena at the potential Yucca Mountain site. This document delineates the design architecture and describes the specific computational algorithms that compose MSTS. Details for using MSTS and sample problems are given in the open-quotes User's Guide and Referenceclose quotes companion document

An update on the drainage of pyogenic lung abscesses

Directory of Open Access Journals (Sweden)

Siraj O Wali

2012-01-01

Full Text Available Most lung abscesses (80-90% are now successfully treated with antibiotics; however, this conservative approach may occasionally fail. When medical treatment fails, pulmonary resection is usually advised. Alternatively, percutaneous transthoracic tube drainage or endoscopic drainage can be considered, though both remain controversial. In this communication, the medical literature focusing on percutaneous tube drainage efficacy, indications, techniques, complications, and mortality, as well as available data regarding endoscopic drainage are reviewed.

Investigating summer flow paths in a Dutch agricultural field using high frequency direct measurements

Science.gov (United States)

Delsman, J. R.; Waterloo, M. J.; Groen, M. M. A.; Groen, J.; Stuyfzand, P. J.

2014-11-01

The search for management strategies to cope with projected water scarcity and water quality deterioration calls for a better understanding of the complex interaction between groundwater and surface water in agricultural catchments. We separately measured flow routes to tile drains and an agricultural ditch in a deep polder in the coastal region of the Netherlands, characterized by exfiltration of brackish regional groundwater flow and intake of diverted river water for irrigation and water quality improvement purposes. We simultaneously measured discharge, electrical conductivity and temperature of these separate flow routes at hourly frequencies, disclosing the complex and time-varying patterns and origins of tile drain and ditch exfiltration. Tile drainage could be characterized as a shallow flow system, showing a non-linear response to groundwater level changes. Tile drainage was fed primarily by meteoric water, but still transported the majority (80%) of groundwater-derived salt to surface water. In contrast, deep brackish groundwater exfiltrating directly in the ditch responded linearly to groundwater level variations and is part of a regional groundwater flow system. We could explain the observed salinity of exfiltrating drain and ditch water from the interaction between the fast-responding pressure distribution in the subsurface that determined groundwater flow paths (wave celerity), and the slow-responding groundwater salinity distribution (water velocity). We found water demand for maintaining water levels and diluting salinity through flushing to greatly exceed the actual sprinkling demand. Counterintuitively, flushing demand was found to be largest during precipitation events, suggesting the possibility of water savings by operational flushing control.

An Optimal Balance between Efficiency and Safety of Urban Drainage Networks

Science.gov (United States)

Seo, Y.

2014-12-01

Urban drainage networks have been developed to promote the efficiency of a system in terms of drainage time so far. Typically, a drainage system is designed to drain water from developed areas promptly as much as possible during floods. In this regard, an artificial drainage system have been considered to be more efficient compared to river networks in nature. This study examined artificial drainage networks and the results indicate they can be less efficient in terms of network configuration compared with river networks, which is counter-intuitive. The case study of 20 catchments in Seoul, South Korea shows that they have wide range of efficiency in terms of network configuration and consequently, drainage time. This study also demonstrates that efficient drainage networks are more sensitive to spatial and temporal rainfall variation such as rainstorm movement. Peak flows increase more than two times greater in effective drainage networks compared with inefficient and highly sinuous drainage networks. Combining these results, this study implies that the layout of a drainage network is an important factor in terms of efficient drainage and also safety in urban catchments. Design of an optimal layout of the drainage network can be an alternative non-structural measures that mitigate potential risks and it is crucial for the sustainability of urban environments.

Subsurface Fire Hazards Technical Report

International Nuclear Information System (INIS)

Logan, R.C.

1999-01-01

The results from this report are preliminary and cannot be used as input into documents supporting procurement, fabrication, or construction. This technical report identifies fire hazards and proposes their mitigation for the subsurface repository fire protection system. The proposed mitigation establishes the minimum level of fire protection to meet NRC regulations, DOE fire protection orders, that ensure fire containment, adequate life safety provisions, and minimize property loss. Equipment requiring automatic fire suppression systems is identified. The subsurface fire hazards that are identified can be adequately mitigated

Shallow groundwater and soil chemistry response to 3 years of subsurface drip irrigation using coalbed-methane-produced water

Energy Technology Data Exchange (ETDEWEB)

Bern, C. R.; Boehlke, A. R.; Engle, M. A.; Geboy, N. J.; Schroeder, K. T.; Zupancic, J. W.

2013-10-04

Disposal of produced waters, pumped to the surface as part of coalbed methane (CBM) development, is a significant environmental issue in the Wyoming portion of the Powder River Basin, USA. High sodium adsorption ratios (SAR) of the waters could degrade agricultural land, especially if directly applied to the soil surface. One method of disposing of CBM water, while deriving beneficial use, is subsurface drip irrigation (SDI), where acidified CBM waters are applied to alfalfa fields year-round via tubing buried 0.92 m deep. Effects of the method were studied on an alluvial terrace with a relatively shallow depth to water table (~3 m). Excess irrigation water caused the water table to rise, even temporarily reaching the depth of drip tubing. The rise corresponded to increased salinity in some monitoring wells. Three factors appeared to drive increased groundwater salinity: (1) CBM solutes, concentrated by evapotranspiration; (2) gypsum dissolution, apparently enhanced by cation exchange; and (3) dissolution of native Na–Mg–SO{sub 4} salts more soluble than gypsum. Irrigation with high SAR (24) water has increased soil saturated paste SAR up to 15 near the drip tubing. Importantly though, little change in SAR has occurred at the surface.

Shallow groundwater and soil chemistry response to 3 years of subsurface drip irrigation using coalbed-methane-produced water

Science.gov (United States)

Bern, Carleton R.; Boehlke, Adam R.; Engle, Mark A.; Geboy, Nicholas J.; Schroeder, K.T.; Zupancic, J.W.

2013-01-01

Disposal of produced waters, pumped to the surface as part of coalbed methane (CBM) development, is a significant environmental issue in the Wyoming portion of the Powder River Basin, USA. High sodium adsorption ratios (SAR) of the waters could degrade agricultural land, especially if directly applied to the soil surface. One method of disposing of CBM water, while deriving beneficial use, is subsurface drip irrigation (SDI), where acidified CBM waters are applied to alfalfa fields year-round via tubing buried 0.92 m deep. Effects of the method were studied on an alluvial terrace with a relatively shallow depth to water table (∼3 m). Excess irrigation water caused the water table to rise, even temporarily reaching the depth of drip tubing. The rise corresponded to increased salinity in some monitoring wells. Three factors appeared to drive increased groundwater salinity: (1) CBM solutes, concentrated by evapotranspiration; (2) gypsum dissolution, apparently enhanced by cation exchange; and (3) dissolution of native Na–Mg–SO4 salts more soluble than gypsum. Irrigation with high SAR (∼24) water has increased soil saturated paste SAR up to 15 near the drip tubing. Importantly though, little change in SAR has occurred at the surface.

Salinity and Temperature Constraints on Microbial Methanogenesis in the Lei-Gong-Huo Mud Volcano of Eastern Taiwan

Science.gov (United States)

Sun, W.; Lin, L.; Wang, P.

2012-12-01

Terrestrial mud volcano is thought to be one of the most important natural sources of methane emission. Previous studies have shown that methane cycling in terrestrial mud volcanoes involves a complex reaction network driven by the interactions between subsurface and surface abiotic and microbial processes. In situ methanogenesis appears to produce methane at quantities exceeding those of deeply-sourced thermogenic methane and the capacities of anaerobic methanotrophy at shallow depth levels, thereby contributing significantly to the methane emission. Various degrees of evaporation at surface also lead to the enhancement of chloride concentrations in pore water, favoring the proliferation of halo-tolerant and/or halophilic methanogens. The goal of this study is to investigate the extent of methanogenesis in terrestrial mud volcanoes by incubating mud slurries with various precursors (H2/CO2, acetate, methanol, and methylamine) at different salinities (up to 2000 mM) and temperatures (up to 50 oC). Methane concentrations were monitored through time and molecular analyses were applied to investigate the changes of methanogenic communities. Methanogenesis was stimulated by any investigated precursor at room temperature. However, the methanogenic response to salinity varied. Of the investigated precursors, H2/CO2 and methyl-compounds (methanol and methylamine) stimulated methanogenesis at all investigated salinities. The rates and yields of hydrogen- and methyl-utilizing methanogenesis declined significantly at salinities greater than 1500 mM. Acetate-utilizing methanogenesis proceeded at salinities less than 700 mM. At 40 oC, methanogenesis was stimulated by all investigated precursors at the in situ salinity (~400 mM). At 50 oC, only H2-utilizing methanogenesis was stimulated. Analyses of terminal restriction fragment length polymorphism (TRFLP) for 16S rRNA genes revealed various patterns upon different precursors and salinities. The TRFLP results combined with

Subsurface barrier verification technologies, informal report

International Nuclear Information System (INIS)

Heiser, J.H.

1994-06-01

One of the more promising remediation options available to the DOE waste management community is subsurface barriers. Some of the uses of subsurface barriers include surrounding and/or containing buried waste, as secondary confinement of underground storage tanks, to direct or contain subsurface contaminant plumes and to restrict remediation methods, such as vacuum extraction, to a limited area. To be most effective the barriers should be continuous and depending on use, have few or no breaches. A breach may be formed through numerous pathways including: discontinuous grout application, from joints between panels and from cracking due to grout curing or wet-dry cycling. The ability to verify barrier integrity is valuable to the DOE, EPA, and commercial sector and will be required to gain full public acceptance of subsurface barriers as either primary or secondary confinement at waste sites. It is recognized that no suitable method exists for the verification of an emplaced barrier's integrity. The large size and deep placement of subsurface barriers makes detection of leaks challenging. This becomes magnified if the permissible leakage from the site is low. Detection of small cracks (fractions of an inch) at depths of 100 feet or more has not been possible using existing surface geophysical techniques. Compounding the problem of locating flaws in a barrier is the fact that no placement technology can guarantee the completeness or integrity of the emplaced barrier. This report summarizes several commonly used or promising technologies that have been or may be applied to in-situ barrier continuity verification

Tracking snowmelt in the subsurface: time-lapse electrical resistivity imaging on an alpine hill slope.

Science.gov (United States)

Thayer, D.; Parsekian, A.; Hyde, K.; Beverly, D.; Speckman, H. N.; Ewers, B. E.

2015-12-01

In the mountain West region the winter snowpack provides more than 70% of our annual water supply. Modeling and predicting the timing and magnitude of snowmelt-driven water yield is difficult due to the complexities of hydrologic systems that move meltwater from snow to rivers. Particular challenges are understanding the temporal and spatial domain of subsurface hydraulic processes at relevant scales, which range from points to catchments. Subsurface characterization often requires borehole instrumentation, which is expensive and extremely difficult to install in remote, rugged terrain. Advancements in non-invasive geophysical methods allow us to monitor changes in geophysical parameters over time and infer changes in hydraulic processes. In the No-Name experimental catchment in the Medicine Bow National Forest in Wyoming, we are conducting a multi-season, time-lapse electrical resistivity imaging survey on a sub-alpine hill slope. This south-facing, partially forested slope ranges from 5 degrees to 35 degrees in steepness and consists of a soil mantle covering buried glacial talus deposits of unknown depth. A permanent grid of down-slope and cross-slope electrode arrays is monitored up to four times a day. The arrays span the entire vertical distance of the slope, from an exposed bedrock ridge to a seasonal drainage below, and cover treed and non-treed areas. Geophysical measurements are augmented by temperature and moisture time-series instrumented below the surface in a contiguous 3 meter borehole. A time-series of multiple resistivity models each day from May to July shows the changing distribution of subsurface moisture during a seasonal drying sequence punctuated by isolated rain events. Spatial patterns of changing moisture indicate that soil and gravel in the top two meters drain into a saturated layer parallel to the slope which overlies less saturated material. These results suggest that water from snowmelt and rain events tends to move down-slope beneath

Nonsurgical drainage of splenic abscess

International Nuclear Information System (INIS)

Berkman, W.A.; Harris, S.A. Jr.; Bernardino, M.E.

1983-01-01

The mortality associated with intraabdominal abscess remains high despite modern surgical methods and antibiotics. Draingae of abscesses of the abdomen, retroperitoneum, pelvis, pancreatic pseudocyst, mediastinum, and lung may be treated effectively by percutaneous catheter placement. In several reports of percutaneous abdominal abscess drainage, only three cases of splenic abscess drainage have been reported. The authors have recently drained two splenic abscesses with the aid of computed tomography (CT) and emphasize several advantages of the percutaneous guided approach

Feasibility of a subsurface storage

International Nuclear Information System (INIS)

1998-11-01

This report analyses the notion of subsurface storage under the scientifical, technical and legal aspects. This reflection belongs to the studies about long duration storage carried out in the framework of the axis 3 of the December 30, 1991 law. The report comprises 3 parts. The first part is a synthesis of the complete subsurface storage study: definitions, aim of the report, very long duration storage paradigm, description files of concepts, thematic synthesis (legal aspects, safety, monitoring, sites, seismicity, heat transfers, corrosion, concretes, R and works, handling, tailings and dismantlement, economy..), multi-criteria/multi-concept cross-analysis. The second part deals with the technical aspects of the subsurface storage: safety approach (long duration impact, radiation protection, mastery of effluents), monitoring strategy, macroscopic inventory of B-type waste packages, inventory of spent fuels, glasses, hulls and nozzles, geological contexts in the French territory (sites selection and characterization), on-site activities, hydrogeological and geochemical aspects, geo-technical works and infrastructures organization, subsurface seismic effects, cooling modes (ventilation, heat transfer with the geologic environment), heat transfer research programs (convection, poly-phase cooling in porous media), handling constraints, concretes (use, behaviour, durability), corrosion of metallic materials, technical-economical analysis, international context (experience feedback from Sweden (CLAB) and the USA (Yucca Mountain), other European and French facilities). The last part of the report is a graphical appendix with 3-D views and schemes of the different concepts. (J.S.)

Subsurface quality assurance practices

International Nuclear Information System (INIS)

1987-08-01

This report addresses only the concept of applying Nuclear Quality Assurance (NQA) practices to repository shaft and subsurface design and construction; how NQA will be applied; and the level of detail required in the documentation for construction of a shaft and subsurface repository in contrast to the level of detail required in the documentation for construction of a traditional mine. This study determined that NQA practices are viable, attainable, as well as required. The study identified the appropriate NQA criteria and the repository's major structures, systems, items, and activities to which the criteria are applicable. A QA plan, for design and construction, and a list of documentation, for construction, are presented. 7 refs., 1 fig., 18 tabs

Characterization of accumulated precipitates during subsurface iron removal

International Nuclear Information System (INIS)

Halem, Doris van; Vet, Weren de; Verberk, Jasper; Amy, Gary; Dijk, Hans van

2011-01-01

Research highlights: → Accumulated iron was not found to clog the well or aquifer after 12 years of subsurface iron removal. → 56-100% of accumulated iron hydroxides were found to be crystalline. → Subsurface iron removal favoured certain soil layers, either due to hydraulics or mineralogy. → Other groundwater constituents, such as manganese and arsenic were found to co-accumulate with iron. - Abstract: The principle of subsurface iron removal for drinking water supply is that aerated water is periodically injected into the aquifer through a tube well. On its way into the aquifer, the injected O 2 -rich water oxidizes adsorbed Fe 2+ , creating a subsurface oxidation zone. When groundwater abstraction is resumed, the soluble Fe 2+ is adsorbed and water with reduced Fe concentrations is abstracted for multiple volumes of the injection water. In this article, Fe accumulation deposits in the aquifer near subsurface treatment wells were identified and characterized to assess the sustainability of subsurface iron removal regarding clogging of the aquifer and the potential co-accumulation of other groundwater constituents, such as As. Chemical extraction of soil samples, with Acid-Oxalate and HNO 3 , showed that Fe had accumulated at specific depths near subsurface iron removal wells after 12 years of operation. Whether it was due to preferred flow paths or geochemical mineralogy conditions; subsurface iron removal clearly favoured certain soil layers. The total Fe content increased between 11.5 and 390.8 mmol/kg ds in the affected soil layers, and the accumulated Fe was found to be 56-100% crystalline. These results suggest that precipitated amorphous Fe hydroxides have transformed to Fe hydroxides of higher crystallinity. These crystalline, compact Fe hydroxides have not noticeably clogged the investigated well and/or aquifer between 1996 and 2008. The subsurface iron removal wells even need less frequent rehabilitation, as drawdown increases more slowly than in

Sedimentation and chemical quality of surface water in the Heart River drainage basin, North Dakota

Science.gov (United States)

Maderak, Marion L.

1966-01-01

The Heart River drainage basin of southwestern North Dakota comprises an area of 3,365 square miles and lies within the Missouri Plateau of the Great Plains province. Streamflow of the Heart River and its tributaries during 1949-58 was directly proportional to .the drainage area. After the construction of Heart Butte Dam in 1949 and Dickinson Dam in 1950, the mean annual streamflow near Mandan was decreased an estimated 10 percent by irrigation, evaporation from the two reservoirs, and municipal use. Processes that contribute sediment to the Heart River are mass wasting, advancement of valley heads, and sheet, lateral stream, and gully erosion. In general, glacial deposits, terraces, and bars of Quaternary age are sources of sand and larger sediment, and the rocks of Tertiary age are sources of clay, silt. and sand. The average annual suspended-sediment discharges near Mandan were estimated to be 1,300,000 tons for 1945-49 and 710,000 tons for 1970-58. The percentage composition of ions in water of the Heart River, based on average concentrations in equivalents per million for selected ranges of streamflow, changes with flow and from station to station. During extremely low flows the water contains a large percentage of sodium and about equal percentages of bicarbonate and .sulfate, and during extremely high flows the water contains a large percentage of calcium plus magnesium and bicarbonate. The concentrations, in parts per million, of most of the ions vary inversely with flow. The water in the reservoirs--Edward Arthur Patterson Lake and Lake Tschida--during normal or above-normal runoff is of suitable quality for public use. Generally, because of medium or high salinity hazards, the successful long-term use of Heart River water for irrigation will depend on a moderate amount of leaching, adequate drainage, ,and the growing of crops that have moderate or good salt tolerance.

Alfalfa (Medicago sativa L.) is tolerant to higher levels of salinity than previous guidelines indicated: Implications of field and greenhouse studies

Science.gov (United States)

Putnam, Daniel H.; Benes, Sharon; Galdi, Giuliano; Hutmacher, Bob; Grattan, Steve

2017-04-01

Alfalfa (Medicago sativa L.) is the most widely grown leguminous forage crop in North America and is valued for high productivity, quality, economic value, and for dairy productivity. Alfalfa has historically been classified as moderately sensitive to saline conditions, with yield declines predicted at >2 dS/m in the saturated soil paste extract. However, greenhouse, sand tank, and field studies over the past five years have confirmed that alfalfa can be grown with limited negative effects at much higher salinity levels. A broad collection of alfalfa varieties has exhibited a range of resistance at irrigation water salinities >5 dS/m ECw in greenhouse trials, with significant variation due to variety. USDA-ARS sand tank studies indicated similar or greater tolerances closer to 8 dS/m in the soil water, in addition to confirmation of significant varietal differences. A three-year field study on clay loam soil with applications of 5-7 dS/m ECw irrigation water indicated normal yields and excellent stand survivability. A second field study in the same soil type with levels from 8-10 dS/m ECw showed yield reductions of 10-15% but economic yields were still achieved at those levels. Field and greenhouse studies were conducted with mixed salt saline sodic waters typical of the San Joaquin Valley of California. Field evaluation of variety performance was subject to greater variation due to secondary salinity-soil interactions including water infiltration and crusting problems, not only salinity per-se. Thus, adequate irrigation water availability to the crop may be as important as salinity in impacting yields under field conditions. Once established, the deep-rooted characteristics of alfalfa enable utilization of deeper subsurface moisture, even at moderate to high salinity levels, as documented by USDA lysimeter studies. Significant advantages to salinity-tolerant varieties have been observed. It will be important to consider specific management factors which may enable

Effect of viscosity on tear drainage and ocular residence time.

Science.gov (United States)

Zhu, Heng; Chauhan, Anuj

2008-08-01

An increase in residence time of dry eye medications including artificial tears will likely enhance therapeutic benefits. The drainage rates and the residence time of eye drops depend on the viscosity of the instilled fluids. However, a quantitative understanding of the dependence of drainage rates and the residence time on viscosity is lacking. The current study aims to develop a mathematical model for the drainage of Newtonian fluids and also for power-law non-Newtonian fluids of different viscosities. This study is an extension of our previous study on the mathematical model of tear drainage. The tear drainage model is modified to describe the drainage of Newtonian fluids with viscosities higher than the tear viscosity and power-law non-Newtonian fluids with rheological parameters obtained from fitting experimental data in literature. The drainage rate through canaliculi was derived from the modified drainage model and was incorporated into a tear mass balance to calculate the transients of total solute quantity in ocular fluids and the bioavailability of instilled drugs. For Newtonian fluids, increasing the viscosity does not affect the drainage rate unless the viscosity exceeds a critical value of about 4.4 cp. The viscosity has a maximum impact on drainage rate around a value of about 100 cp. The trends are similar for shear thinning power law fluids. The transients of total solute quantity, and the residence time agrees at least qualitatively with experimental studies. A mathematical model has been developed for the drainage of Newtonian fluids and power-law fluids through canaliculi. The model can quantitatively explain different experimental observations on the effect of viscosity on the residence of instilled fluids on the ocular surface. The current study is helpful for understanding the mechanism of fluid drainage from the ocular surface and for improving the design of dry eye treatments.

The long-term resistance mechanisms, critical irrigation threshold and relief capacity shown by Eugenia myrtifolia plants in response to saline reclaimed water

DEFF Research Database (Denmark)

Acosta-Motos, José Ramón; Hernández, José Antonio; Álvarez, Sara

2017-01-01

water potential, the relative water content of leaves, leaf stomatal conductance, the leaf photosynthetic rate, water-use efficiency and accumulated evapotranspiration in order to limit water loss; and 4) changes in the antioxidant defence mechanisms. These different responses induced oxidative stress...... to different electric conductivities of the treatments. Based on these premises, we studied the long-term effect of three reclaimed water treatments with different saline concentrations on Eugenia myrtifolia plants. We also looked at the ability of these plants to recover when no drainage was applied. The RW...... with the highest electric conductivity (RW3, EC = 6.96 dS m(-1)) provoked a number of responses to salinity in these plants, including: 1) accumulation and extrusion of phytotoxic ions in roots; 2) a decrease in the shoot/root ratio, leaf area, number of leaves; 3) a decrease in root hydraulic conductivity, leaf...

Development of a regional hydrologic soil model and application to the Beerze-Reusel drainage basin

International Nuclear Information System (INIS)

Kolditz, O.; Du, Y.; Buerger, C.; Delfs, J.; Kuntz, D.; Beinhorn, M.; Hess, M.; Wang, W.; Grift, B. van der; Stroet, C. te

2007-01-01

The soil compartment is an important interface between the atmosphere and the subsurface hydrosphere. In this paper a conceptual approach for regional hydrologic soil modelling (RHSM) is presented, which provides two important qualities for modelling. First, the soil compartment is directly coupled to the atmosphere via the land surface and to the aquifers. Second, extremely fine (5 cm vertical) resolutions of the soil system can be realized at regional scales (several hundreds of km 2 ). This high-resolution modelling could be achieved by parallel computation techniques. The RHSM approach is applied to the Beerze-Reusel drainage basin, which belongs to the Meuse River basin. Moisture transport in the soil system was calculated with extremely high vertical resolution at a regional scale based on rainfall-evaporation data for the year 2000. As a result, highly resolved regional groundwater recharge pattern addressing the heterogeneity of soil systems could be determined. - A real case application of concept of regional hydrologic soil modelling is presented

Coupling of a distributed stakeholder-built system dynamics socio-economic model with SAHYSMOD for sustainable soil salinity management. Part 2: Model coupling and application

Science.gov (United States)

Inam, Azhar; Adamowski, Jan; Prasher, Shiv; Halbe, Johannes; Malard, Julien; Albano, Raffaele

2017-08-01

Many simulation models focus on simulating a single physical process and do not constitute balanced representations of the physical, social and economic components of a system. The present study addresses this challenge by integrating a physical (P) model (SAHYSMOD) with a group (stakeholder) built system dynamics model (GBSDM) through a component modeling approach based on widely applied tools such as MS Excel, Python and Visual Basic for Applications (VBA). The coupled model (P-GBSDM) was applied to test soil salinity management scenarios (proposed by stakeholders) for the Haveli region of the Rechna Doab Basin in Pakistan. Scenarios such as water banking, vertical drainage, canal lining, and irrigation water reallocation were simulated with the integrated model. Spatiotemporal maps and economic and environmental trade-off criteria were used to examine the effectiveness of the selected management scenarios. After 20 years of simulation, canal lining reduced soil salinity by 22% but caused an initial reduction of 18% in farm income, which requires an initial investment from the government. The government-sponsored Salinity Control and Reclamation Project (SCARP) is a short-term policy that resulted in a 37% increase in water availability with a 12% increase in farmer income. However, it showed detrimental effects on soil salinity in the long term, with a 21% increase in soil salinity due to secondary salinization. The new P-GBSDM was shown to be an effective platform for engaging stakeholders and simulating their proposed management policies while taking into account socioeconomic considerations. This was not possible using the physically based SAHYSMOD model alone.

Drawing the subsurface : an integrative design approach

NARCIS (Netherlands)

Hooimeijer, F.L.; Lafleur, F.; Trinh, T.T.; Gogu, Constantin Radu; Campbell, Diarmad; de Beer, Johannes

2017-01-01

The sub-surface, with its man-made and natural components, plays an important, if not crucial, role in the urban climate and global energy transition. On the one hand, the sub-surface is associated with a variety of challenges such as subsidence, pollution, damage to infrastructure and shortages of

Preoperative biliary drainage in hilar cholangiocarcinoma: When and how?

Science.gov (United States)

Paik, Woo Hyun; Loganathan, Nerenthran; Hwang, Jin-Hyeok

2014-01-01

Hilar cholangiocarcinoma is a tumor of the extrahepatic bile duct involving the left main hepatic duct, the right main hepatic duct, or their confluence. Biliary drainage in hilar cholangiocarcinoma is sometimes clinically challenging because of complexities associated with the level of biliary obstruction. This may result in some adverse events, especially acute cholangitis. Hence the decision on the indication and methods of biliary drainage in patients with hilar cholangiocarcinoma should be carefully evaluated. This review focuses on the optimal method and duration of preoperative biliary drainage (PBD) in resectable hilar cholangiocarcinoma. Under certain special indications such as right lobectomy for Bismuth type IIIA or IV hilar cholangiocarcinoma, or preoperative portal vein embolization with chemoradiation therapy, PBD should be strongly recommended. Generally, selective biliary drainage is enough before surgery, however, in the cases of development of cholangitis after unilateral drainage or slow resolving hyperbilirubinemia, total biliary drainage may be considered. Although the optimal preoperative bilirubin level is still a matter of debate, the shortest possible duration of PBD is recommended. Endoscopic nasobiliary drainage seems to be the most appropriate method of PBD in terms of minimizing the risks of tract seeding and inflammatory reactions. PMID:24634710

Improving the biodegradative capacity of subsurface bacteria

International Nuclear Information System (INIS)

Romine, M.F.; Brockman, F.J.

1993-04-01

The continual release of large volumes of synthetic materials into the environment by agricultural and industrial sources over the last few decades has resulted in pollution of the subsurface environment. Cleanup has been difficult because of the relative inaccessibility of the contaminants caused by their wide dispersal in the deep subsurface, often at low concentrations and in large volumes. As a possible solution for these problems, interest in the introduction of biodegradative bacteria for in situ remediation of these sites has increased greatly in recent years (Timmis et al. 1988). Selection of biodegradative microbes to apply in such cleanup is limited to those strains that can survive among the native bacterial and predator community members at the particular pH, temperature, and moisture status of the site (Alexander, 1984). The use of microorganisms isolated from subsurface environments would be advantageous because the organisms are already adapted to the subsurface conditions. The options are further narrowed to strains that are able to degrade the contaminant rapidly, even in the presence of highly recalcitrant anthropogenic waste mixtures, and in conditions that do not require addition of further toxic compounds for the expression of the biodegradative capacity (Sayler et al. 1990). These obstacles can be overcome by placing the genes of well-characterized biodegradative enzymes under the control of promoters that can be regulated by inexpensive and nontoxic external factors and then moving the new genetic constructs into diverse groups of subsurface microbes. ne objective of this research is to test this hypothesis by comparing expression of two different toluene biodegradative enzymatic pathways from two different regulatable promoters in a variety of subsurface isolates

Modeling a Sustainable Salt Tolerant Grass-Livestock Production System under Saline Conditions in the Western San Joaquin Valley of California

Directory of Open Access Journals (Sweden)

Stephen R. Kaffka

2013-09-01

Full Text Available Salinity and trace mineral accumulation threaten the sustainability of crop production in many semi-arid parts of the world, including California’s western San Joaquin Valley (WSJV. We used data from a multi-year field-scale trial in Kings County and related container trials to simulate a forage-grazing system under saline conditions. The model uses rainfall and irrigation water amounts, irrigation water quality, soil, plant, and atmospheric variables to predict Bermuda grass (Cynodon dactylon (L. Pers. growth, quality, and use by cattle. Simulations based on field measurements and a related container study indicate that although soil chemical composition is affected by irrigation water quality, irrigation timing and frequency can be used to mitigate salt and trace mineral accumulation. Bermuda grass yields of up to 12 Mg dry matter (DM·ha−1 were observed at the field site and predicted by the model. Forage yield and quality supports un-supplemented cattle stocking rates of 1.0 to 1.2 animal units (AU·ha−1. However, a balance must be achieved between stocking rate, desired average daily gain, accumulation of salts in the soil profile, and potential pollution of ground water from drainage and leaching. Using available weather data, crop-specific parameter values and field scale measurements of soil salinity and nitrogen levels, the model can be used by farmers growing forages on saline soils elsewhere, to sustain forage and livestock production under similarly marginal conditions.

Contaminant geochemistry. Interactions and transport in the subsurface environment

Energy Technology Data Exchange (ETDEWEB)

Berkowitz, Brian; Dror, Ishai; Yaron, Bruno [Weizmann Institute of Science, Rehovot (Israel). Dept. of Environmental Sciences and Energy Research

2008-07-01

This book combines earth science, subsurface hydrology and environmental geochemistry, providing a comprehensive background for specialists interested in the protection and sustainable management of the subsurface environment. The reader is introduced to the chemistry of contaminants, which usually disturb the natural equilibrium in the subsurface as a result of human activity. The major focus of the book is on contaminant reactions in soil solutions, groundwater and porous media solid phases, accounting for their persistence and transformation in the subsurface, as they are transported from the land surface into groundwater. Discussions on selected case studies are provided. (orig.)

Subsurface lateral flow from hillslope and its contribution to nitrate loading in streams through an agricultural catchment during subtropical rainstorm events

Directory of Open Access Journals (Sweden)

B. Zhang

2011-10-01

Full Text Available Subsurface lateral flow from agricultural hillslopes is often overlooked compared with overland flow and tile drain flow, partly due to the difficulties in monitoring and quantifying. The objectives of this study were to examine how subsurface lateral flow generated through soil pedons from cropped hillslopes and to quantify its contribution to nitrate loading in the streams through an agricultural catchment in the subtropical region of China. Profiles of soil water potential along hillslopes and stream hydro-chemographs in a trenched stream below a cropped hillslope and at the catchment outlet were simultaneously recorded during two rainstorm events. The dynamics of soil water potential showed positive matrix soil water potential over impermeable soil layer at 0.6 to 1.50 m depths during and after the storms, indicating soil water saturation and drainage processes along the hillslopes irrespective of land uses. The hydro-chemographs in the streams, one trenched below a cropped hillslope and one at the catchment outlet, showed that the concentrations of particulate nitrogen and phosphorus corresponded well to stream flow during the storm, while the nitrate concentration increased on the recession limbs of the hydrographs after the end of the storm. All the synchronous data revealed that nitrate was delivered from the cropped hillslope through subsurface lateral flow to the streams during and after the end of the rainstorms. A chemical mixing model based on electricity conductivity (EC and H⁺ concentration was successfully established, particularly for the trenched stream. The results showed that the subsurface lateral flow accounted for 29% to 45% of total stream flow in the trenched stream, responsible for 86% of total NO₃⁻-N loss (or 26% of total N loss, and for 5.7% to 7.3% of total stream flow at the catchment outlet, responsible for about 69% of total NO₃⁻-N loss (or 28% of total N

Extracting subsurface fingerprints using optical coherence tomography

CSIR Research Space (South Africa)

Akhoury, SS

2015-02-01

Full Text Available Subsurface Fingerprints using Optical Coherence Tomography Sharat Saurabh Akhoury, Luke Nicholas Darlow Modelling and Digital Science, Council for Scientific and Industrial Research, Pretoria, South Africa Abstract Physiologists have found... approach to extract the subsurface fingerprint representation using a high-resolution imaging technology known as Optical Coherence Tomography (OCT). ...

Ecological, biogeochemical and salinity changes in coastal lakes and wetlands over the last 200 years

Science.gov (United States)

Roberts, Lucy; Holmes, Jonathan; Horne, David

2016-04-01

Shallow lakes provide extensive ecosystem services and are ecologically important aquatic resources supporting a diverse flora and fauna. In marginal-marine areas, where such lakes are subjected to the multiple pressures of coastal erosion, sea level rise, increasing sea surface temperature and increasing frequency and intensity of storm surges, environments are complex and unstable. They are characterised by physico-chemical variations due to climatic (precipitation/evaporation cycles) and dynamic factors (tides, currents, freshwater drainage and sea level changes). Combined with human activity in the catchment these processes can alter the salinity, habitat and ecology of coastal fresh- to brackish water ecosystems. In this study the chemical and biological stability of coastal lakes forming the Upper Thurne catchment in the NE of the Norfolk Broads, East Anglia, UK are seriously threatened by long-term changes in salinity resulting from storm surges, complex hydrogeology and anthropogenic activity in the catchment. Future management decisions depend on a sound understanding of the potential ecological impacts, but such understanding is limited by short-term observations and measurements. This research uses palaeolimnological approaches, which can be validated and calibrated with historical records, to reconstruct changes in the aquatic environment on a longer time scale than can be achieved by observations alone. Here, salinity is quantitatively reconstructed using the trace-element geochemistry (Sr/Ca and Mg/Ca) of low Mg-calcite shells of Ostracoda (microscopic bivalved crustaceans) and macrophyte and macroinvertebrate macrofossil remains are used as a proxy to assess ecological change in response to variations in salinity. δ13C values of Cladocera (which are potentially outcompeted by the mysid Neomysis integer with increasing salinity and eutrophication) can be used to reconstruct carbon cycling and energy pathways in lake food webs, which alongside

Drainage of Splenic Abscess: A Case Report | Kombo | Nigerian ...

African Journals Online (AJOL)

... and was managed by tube drainage. His post operative recovery was uneventful. Conclusion: Tube drainage of the splenic abscess is encouraged if there is easy access to the abscess and there is evidence of residual splenic tissue in the critically ill patient. Key Word: Tube drainage, splenic abscess, splenectomy.

The construction technology of Chinese ancient city drainage facilities

Science.gov (United States)

Hequn, Li; Yufengyun

2018-03-01

In ancient china, according to the local natural environment, a variety of drainage facilities were built in order to excrete rainwater, domestic sewage, production wastewater and so on. These drainage facilities were mainly made of pottery, bricks, wood, stone, etc. For example, ceramic water pipelines, buried in the ground, connect together one by one, and there was a slight drop from one end to the other in favor of drainage. These measures can also be used for reference in today’s urban drainage and flood control.

Drainage divides, Massachusetts; Blackstone and Thames River basins

Science.gov (United States)

Krejmas, Bruce E.; Wandle, S. William

1982-01-01

Drainage boundaries for selected subbasins of the Blackstone and Thames River basins in eastern Hampden, eastern Hampshire, western Norfolk, southern Middlesex, and southern Worcester Counties, Massachusetts, are delineated on 12 topographic quadrangle maps at a scale of 1:24,000. Drainage basins are shown for all U.S. Geological Survey data-collection sites and for mouths of major rivers. Drainage basins are shown for the outlets of lakes or ponds and for streams where the drainage area is greater than 3 square miles. Successive sites along watercourses are indicated where the intervening area is at least 6 miles on tributary streams or 15 square miles along the Blackstone River, French River, or Quinebaug River. (USGS)

Application of BIM Technology in Building Water Supply and Drainage Design

Science.gov (United States)

Wei, Tianyun; Chen, Guiqing; Wang, Junde

2017-12-01

Through the application of BIM technology, the idea of building water supply and drainage designers can be related to the model, the various influencing factors to affect water supply and drainage design can be considered more comprehensively. BIM(Building information model) technology assist in improving the design process of building water supply and drainage, promoting the building water supply and drainage planning, enriching the building water supply and drainage design method, improving the water supply and drainage system design level and building quality. Combined with fuzzy comprehensive evaluation method to analyze the advantages of BIM technology in building water supply and drainage design. Therefore, application prospects of BIM technology are very worthy of promotion.

Finding a solution: Heparinised saline versus normal saline in the maintenance of invasive arterial lines in intensive care.

Science.gov (United States)

Everson, Matthew; Webber, Lucy; Penfold, Chris; Shah, Sanjoy; Freshwater-Turner, Dan

2016-11-01

We assessed the impact of heparinised saline versus 0.9% normal saline on arterial line patency. Maintaining the patency of arterial lines is essential for obtaining accurate physiological measurements, enabling blood sampling and minimising line replacement. Use of heparinised saline is associated with risks such as thrombocytopenia, haemorrhage and mis-selection. Historical studies draw variable conclusions but suggest that normal saline is at least as effective at maintaining line patency, although recent evidence has questioned this. We conducted a prospective analysis of the use of heparinised saline versus normal saline on unselected patients in the intensive care of our hospital. Data concerning duration of 471 lines insertion and reason for removal was collected. We found a higher risk of blockage for lines flushed with normal saline compared with heparinised saline (RR = 2.15, 95% CI 1.392-3.32, p  ≤ 0.001). Of the 56 lines which blocked initially (19 heparinised saline and 37 normal saline lines), 16 were replaced with new lines; 5 heparinised saline lines and 11 normal saline lines were reinserted; 5 of these lines subsequently blocked again, 3 of which were flushed with normal saline. Our study demonstrates a clinically important reduction in arterial line longevity due to blockages when flushed with normal saline compared to heparinised saline. We have determined that these excess blockages have a significant clinical impact with further lines being inserted after blockage, resulting in increased risks to patients, wasted time and cost of resources. Our findings suggest that the current UK guidance favouring normal saline flushes should be reviewed.

Percutaneous transhepatic biliary drainage: analysis of 175 cases

Energy Technology Data Exchange (ETDEWEB)

Suh, Kyung Jin; Lee, Sang Kwon; Kim, Tae Hun; Kim, Yong Joo; Kang, Duk Sik [College of Medicine, Kyungpook National Univ., Daegu (Korea, Republic of)

1990-10-15

Percutaneous transhepatic biliary drainage is a safe, effective and palliative means of treatment in biliary obstruction, especially in cases with malignant obstruction which are inoperable. 175 cases of transhepatic biliary drainage were performed on 119 patients with biliary obstruction from January 1985 to June 1989 at Kyung-pook National University Hospital. The causes of obstructive jaundice were 110 malignant diseases and 9 benign diseases. The most common indication for drainage was palliative intervention of obstruction secondary to malignant tumor in 89 cases. 86 cases of external drainage were performed including 3 cases of left duct approach, 29 cases of external-internal drainage and 60 cases of endoprosthesis. In external and external-internal drainages, immediate major complications (11.9%) occurred, including not restricted to, but sepsis, bile peritonitis and hemobilia. Delayed major complications (42.9%) were mainly catheter related. The delayed major complication of endoprosthesis resulted from obstruction of the internal stent. The mean time period to reobstruction of the internal stent was about 12 weeks. To improve management status, regular follow-up is required, as is education of both patients and their families as to when immediate clinical attention is mandated. Close communication amongst the varying medical specialities involved will be necessary to provide optional treatment for each patient.

Percutaneous transhepatic biliary drainage: analysis of 175 cases

International Nuclear Information System (INIS)

Suh, Kyung Jin; Lee, Sang Kwon; Kim, Tae Hun; Kim, Yong Joo; Kang, Duk Sik

1990-01-01

Percutaneous transhepatic biliary drainage is a safe, effective and palliative means of treatment in biliary obstruction, especially in cases with malignant obstruction which are inoperable. 175 cases of transhepatic biliary drainage were performed on 119 patients with biliary obstruction from January 1985 to June 1989 at Kyung-pook National University Hospital. The causes of obstructive jaundice were 110 malignant diseases and 9 benign diseases. The most common indication for drainage was palliative intervention of obstruction secondary to malignant tumor in 89 cases. 86 cases of external drainage were performed including 3 cases of left duct approach, 29 cases of external-internal drainage and 60 cases of endoprosthesis. In external and external-internal drainages, immediate major complications (11.9%) occurred, including not restricted to, but sepsis, bile peritonitis and hemobilia. Delayed major complications (42.9%) were mainly catheter related. The delayed major complication of endoprosthesis resulted from obstruction of the internal stent. The mean time period to reobstruction of the internal stent was about 12 weeks. To improve management status, regular follow-up is required, as is education of both patients and their families as to when immediate clinical attention is mandated. Close communication amongst the varying medical specialities involved will be necessary to provide optional treatment for each patient

Subsurface low pH and carbonate saturation state of aragonite on China side of the North Yellow Sea: combined effects of global atmospheric CO2 increase, regional environmental changes, and local biogeochemical processes

Science.gov (United States)

Zhai, W.-D.; Zheng, N.; Huo, C.; Xu, Y.; Zhao, H.-D.; Li, Y.-W.; Zang, K.-P.; Wang, J.-Y.; Xu, X.-M.

2013-02-01

Based upon seven field surveys conducted between May 2011 and January 2012, we investigated pH, carbonate saturation state of aragonite (Ωarag), and ancillary parameters on the Chinese side of the North Yellow Sea, a western North Pacific continental margin of major economic importance. Subsurface waters were nearly in equilibrium with air in May and June. From July to October, the fugacity of CO2 (fCO2) of bottom water gradually increased to 697 ± 103 μatm and pH decreased to 7.83 ± 0.07 due to respiration/remineralization processes of primary production induced biogenic particles. In November and January, bottom water fCO2 decreased and pH gradually returned to an air-equilibrated level due to cooling enhanced vertical mixing. The corresponding bottom water Ωarag was 1.74 ± 0.17 (May), 1.77 ± 0.26 (June), 1.70 ± 0.26 (July), 1.72 ± 0.33 (August), 1.32 ± 0.31 (October), 1.50 ± 0.28 (November), and 1.41 ± 0.12 (January). Critically low Ωarag values of 1.0 to 1.2 were mainly observed in subsurface waters in a salinity range of 31.5-32.5 psu in October and November, accounting for ~ 10% of the North Yellow Sea area. Water mass derived from the adjacent Bohai Sea had a typical water salinity of 30.5-31.5 psu, and bottom water Ωarag values ranged mostly between 1.6 and 2.4. This study showed that the carbonate system in the North Yellow Sea was substantially influenced by global atmospheric CO2 increase. The community respiration/remineralization rates in typical North Yellow Sea bottom water mass were estimated at 0.55-1.0 μmol O2 kg-1 d-1 in warm seasons, leading to seasonal drops in subsurface pH and Ωarag. Outflow of the Bohai Sea water mass counteracted the subsurface Ωarag reduction in the North Yellow Sea.

Defining the Post-Machined Sub-surface in Austenitic Stainless Steels

Science.gov (United States)

Srinivasan, N.; Sunil Kumar, B.; Kain, V.; Birbilis, N.; Joshi, S. S.; Sivaprasad, P. V.; Chai, G.; Durgaprasad, A.; Bhattacharya, S.; Samajdar, I.

2018-06-01

Austenitic stainless steels grades, with differences in chemistry, stacking fault energy, and thermal conductivity, were subjected to vertical milling. Anodic potentiodynamic polarization was able to differentiate (with machining speed/strain rate) between different post-machined sub-surfaces in SS 316L and Alloy A (a Cu containing austenitic stainless steel: Sanicroe 28™), but not in SS 304L. However, such differences (in the post-machined sub-surfaces) were revealed in surface roughness, sub-surface residual stresses and misorientations, and in the relative presence of sub-surface Cr2O3 films. It was shown, quantitatively, that higher machining speed reduced surface roughness and also reduced the effective depths of the affected sub-surface layers. A qualitative explanation on the sub-surface microstructural developments was provided based on the temperature-dependent thermal conductivity values. The results herein represent a mechanistic understanding to rationalize the corrosion performance of widely adopted engineering alloys.

Defining the Post-Machined Sub-surface in Austenitic Stainless Steels

Science.gov (United States)

Srinivasan, N.; Sunil Kumar, B.; Kain, V.; Birbilis, N.; Joshi, S. S.; Sivaprasad, P. V.; Chai, G.; Durgaprasad, A.; Bhattacharya, S.; Samajdar, I.

2018-04-01

Austenitic stainless steels grades, with differences in chemistry, stacking fault energy, and thermal conductivity, were subjected to vertical milling. Anodic potentiodynamic polarization was able to differentiate (with machining speed/strain rate) between different post-machined sub-surfaces in SS 316L and Alloy A (a Cu containing austenitic stainless steel: Sanicroe 28™), but not in SS 304L. However, such differences (in the post-machined sub-surfaces) were revealed in surface roughness, sub-surface residual stresses and misorientations, and in the relative presence of sub-surface Cr2O3 films. It was shown, quantitatively, that higher machining speed reduced surface roughness and also reduced the effective depths of the affected sub-surface layers. A qualitative explanation on the sub-surface microstructural developments was provided based on the temperature-dependent thermal conductivity values. The results herein represent a mechanistic understanding to rationalize the corrosion performance of widely adopted engineering alloys.

Superficial drainage studies in open-pit mines

International Nuclear Information System (INIS)

Teixeira Junior, P.B.; Leite, C.B.B.

1984-01-01

Drainage studies concerning large open-pit mining projects can be of vital importance throughout the mining activity itself as they may assist in avoiding activity interruptions due to drainage problems, therefore representing substantial savings. These studies should, in fact, be carried out from the initial activity stages and shall be considered in operational, project and planning decisions in order to optimize results and reduce costs. This specific study presents a drainage study systematization proposal, enphasazing economic decision criteria. The authors comment on studies of this nature developed at the Caldas uranium mine - NUCLEBRAS. (D.J.M.) [pt

Gravity Drainage Kinetics of Papermaking Fibrous Suspensions

Directory of Open Access Journals (Sweden)

Przybysz Piotr

2014-12-01

Full Text Available The study analyses application possibilities of filtration and thickening models in evaluation of papermaking suspension drainage rate. The authors proposed their own method to estimate the drainage rate on the basis of an existing Ergun capillary model of liquid flow through a granular material. The proposed model was less sensitive to porosity changes than the Ergun model. An empirical verification proved robustness of the proposed approach. Taking into account discrepancies in the published data concerning how the drainage velocity of papermaking suspension is defined, this study examines which of the commonly applied models matches experimental results the best.

Geomorphic Drainage Capture Recorded by Oxygen Isotopes of Green River Formation Lacustrine Mudstone, Eocene, Wyoming

Science.gov (United States)

Doebbert, A. C.; Booth, A. L.; Carroll, A.; Chamberlain, C.; Rhodes, M.

2005-12-01

The isotopic composition of cement and other meteoric precipitates are increasingly being used to interpret orogenic uplift histories, based on the relationship between altitude and rainwater δ18O. However, other variables such as changing regional drainage patterns may also affect the downstream composition of surface waters, especially when multiple drainages commingle in a lake. The Green River Formation contains some of the best documented lacustrine deposits in the world, making it ideal for examining such issues. Carbonate mudstone in balanced-fill facies of the lower LaClede Bed averages 3.41‰ (PDB), and records a deep, saline to brackish lake that fluctuated near its sill. In contrast, overfilled facies of the upper LaClede Bed record a freshwater lake, and δ18O reaches values as low as -9.72‰. This transition occurred shortly after deposition of the Analcite Tuff at 48.94 ± 0.12 Ma (Smith et al., 2003), and was geologically abrupt. Based on 40Ar/39Ar-calibrated sediment accumulation rates it required no more than 200-300 ky. An almost identical transition occurs in two cores separated by about 30 km, making local diagenesis an unlikely cause. The magnitude of δ18O change is similar to that in some uplift studies, but its rapidity virtually excludes uplift as a controlling mechanism. Instead, we propose that both the change in sedimentation and the sharp decrease in δ18O are the result of a drainage capture event. The addition of a new drainage to the basin may have adjusted isotopic values in two ways: by introducing runoff with relatively low δ18O, and by decreasing residence time (and therefore evaporation) of lake water. Decreasing 87Sr/86Sr across the same transition suggests that the newly added waters may have been sourced from rising volcanic topography to the north in the Absaroka province. Although this rising topography allows for the possibility of some uplift component, the rate of change in lacustrine δ18O is consistent with

Surgical vs ultrasound-guided drainage of deep neck space abscesses: a randomized controlled trial: surgical vs ultrasound drainage.

Science.gov (United States)

Biron, Vincent L; Kurien, George; Dziegielewski, Peter; Barber, Brittany; Seikaly, Hadi

2013-02-26

Deep neck space abscesses (DNAs) are relatively common otolaryngology-head and neck surgery emergencies and can result in significant morbidity with potential mortality. Traditionally, surgical incision and drainage (I&D) with antibiotics has been the mainstay of treatment. Some reports have suggested that ultrasound-guided drainage (USD) is a less invasive and effective alternative in select cases. To compare I&D vs USD of well-defined DNAs, using a randomized controlled clinical trial design. The primary outcome measure was effectiveness (length of hospital stay (LOHS) and safety), and the secondary outcome measure was overall cost to the healthcare system. Patients presenting to the University of Alberta Emergency Department with a well-defined deep neck space abscess were recruited in the study. Patients were randomized to surgical or US-guided drainage, placed on intravenous antibiotics and admitted with airway precautions. Following drainage with either intervention, abscess collections were cultured and drains were left in place until discharge. Seventeen patients were recruited in the study. We found a significant difference in mean LOHS between patients who underwent USD (3.1 days) vs I&D (5.2 days). We identified significant cost savings associated with USD with a 41% cost reduction in comparison to I&D. USD drainage of deep neck space abscesses in a certain patient population is effective, safe, and results in a significant cost savings to the healthcare system.

Improved drainage with active chest tube clearance.

Science.gov (United States)

Shiose, Akira; Takaseya, Tohru; Fumoto, Hideyuki; Arakawa, Yoko; Horai, Tetsuya; Boyle, Edward M; Gillinov, A Marc; Fukamachi, Kiyotaka

2010-05-01

This study was performed to evaluate the efficacy of a novel chest drainage system. This system employs guide wire-based active chest tube clearance to improve drainage and maintain patency. A 32 Fr chest tube was inserted into pleural cavities of five pigs. On the left, a tube was connected to the chest canister, and on the right, the new system was inserted between the chest tube and chest canister. Acute bleeding was mimicked by periodic infusion of blood. The amount of blood drained from each chest cavity was recorded every 15 min for 2 h. After completion of the procedure, all residual blood and clots in each chest cavity were assessed. The new system remained widely patent, and the amount of drainage achieved with this system (670+/-105 ml) was significantly (P=0.01) higher than that with the standard tube (239+/-131 ml). The amount of retained pleural blood and clots with this system (150+/-107 ml) was significantly (P=0.04) lower than that with the standard tube (571+/-248 ml). In conclusion, a novel chest drainage system with active tube clearance significantly improved drainage without tube manipulations. 2010 Published by European Association for Cardio-Thoracic Surgery. All rights reserved.

Fluoroscopy guided percutaneous catheter drainage of pneumothorax in good mid-term patency with tube drainage

International Nuclear Information System (INIS)

Park, Ga Young; Oh, Joo Hyung; Yoon, Yup; Sung, Dong Wook

1995-01-01

To evaluate efficacy and the safety of percutaneous catheter drainage in patients with pneumothorax that is difficult to treat with closed thoracotomy. We retrospectively reviewed effectiveness of percutaneous catheter drainage (PCD) in 10 patients with pneumothorax. The catheter was inserted under fluoroscopic guidance. Seven patients had spontaneous pneumothorax caused by tuberculosis (n =4), reptured bullae (n = 2), and histiocytosis-X (n = 1). Three patients had iatrogenic pneumothorax caused by trauma (n = 1) and surgery (n = 2). All procedures were performed by modified Seldinger's method by using 8F-20F catheter. All catheter were inserted successfully. In 9 of 10 patients, the procedure was curative without further therapy. Duration of catheter insertion ranged from 1 day to 26 days. In the remaining 1 patient in whom multiple pneumothorax occurred after operation, catheter insertion was performed twice. Percutaneous catheter drainage under fluoroscopic guidance is effective and safe procedure for treatment of pneumothorax in patients with failed closed thoracotomy

Fluoroscopy guided percutaneous catheter drainage of pneumothorax in good mid-term patency with tube drainage

Energy Technology Data Exchange (ETDEWEB)

Park, Ga Young; Oh, Joo Hyung; Yoon, Yup; Sung, Dong Wook [Kyung Hee University Hospital, Seoul (Korea, Republic of)

1995-10-15

To evaluate efficacy and the safety of percutaneous catheter drainage in patients with pneumothorax that is difficult to treat with closed thoracotomy. We retrospectively reviewed effectiveness of percutaneous catheter drainage (PCD) in 10 patients with pneumothorax. The catheter was inserted under fluoroscopic guidance. Seven patients had spontaneous pneumothorax caused by tuberculosis (n =4), reptured bullae (n = 2), and histiocytosis-X (n = 1). Three patients had iatrogenic pneumothorax caused by trauma (n = 1) and surgery (n = 2). All procedures were performed by modified Seldinger's method by using 8F-20F catheter. All catheter were inserted successfully. In 9 of 10 patients, the procedure was curative without further therapy. Duration of catheter insertion ranged from 1 day to 26 days. In the remaining 1 patient in whom multiple pneumothorax occurred after operation, catheter insertion was performed twice. Percutaneous catheter drainage under fluoroscopic guidance is effective and safe procedure for treatment of pneumothorax in patients with failed closed thoracotomy.

Evaluation of the sustainability of road drainage systems

Science.gov (United States)

García-Diez, Iván; Palencia, Covadonga; Fernández Raga, María

2017-04-01

Water is the most erosive agent that exists on the linear structures, because they are constantly subjected to outdoor condition like irregular infiltration, frosts and different rain intensities. Another variables that highly influence in the entire lifetime of a natural drainage system are the spatial and temporal variability of the rainfall, the soil, the vegetation cover and the design. All this factors are affecting the vulnerability of the clearings and embankments, by wearing away the weakest materials which surround the roads or train rails, producing erosion and very bumpy surfaces. The result is that the original pattern, developped to disminished the lost of soil, is not properly working and it cannot eliminate water, with the consequence destruction of the linear structure after several rainfall periods, and the accumulation of material down slope. The propose of this research focuses on analysing the drainage systems used in spanish roads and railways lines. For this purpose, a revision of the literature has been done, and the main drainage solutions have been recovered, carrying out an evaluation of them from an environmental point of view. This procedure has been requested by several authors in the past (Nwa, E.U. & Twocock, J.G., 1969; Goulter, I.C., 1992), together with the need of designing a more sustainable drainage system. The final objective of this complete revision is to compare objetively the designs to valuate them in order to develop a new drainage patter which minimize the erosion, increasing the durability and effectiveness of the drainage system. For this purpose, it is neccesary to assure that all the systems will be compare under similar parameters of flow rate, vegetation, substrate, lenght, slope and total section. Only the channels pattern and water distribution will change. The analysis has been done following Liu, H. & Zhu, X.B., (2012), who pointed out that the main parameters to take into account to select a road drainage

Subdural drainage versus subperiosteal drainage in burr-hole trepanation for symptomatic chronic subdural hematomas.

Science.gov (United States)

Bellut, David; Woernle, Christoph Michael; Burkhardt, Jan-Karl; Kockro, Ralf Alfons; Bertalanffy, Helmut; Krayenbühl, Niklaus

2012-01-01

Symptomatic chronic subdural hematoma (scSDH) is one of the most frequent diseases in neurosurgical practice, and its incidence is increasing. However, treatment modalities are still controversial. The aim of this retrospective single-center study is to compare for the first time two surgical methods in the treatment of subdural hematoma that have been proven to be efficient in previous studies in a direct comparison. We analyzed the data of 143 scSDHs in 113 patients undergoing surgery for subdural hematoma with placement of subperiosteal or subdural drainage after double burr-hole trepanation for hematoma evacuation. Overall, there were no statistically significant differences regarding general patient characteristics, preoperative and postoperative symptoms, postoperative hematoma remnant, rates of recurrences, mortality, complications, and outcome at discharge and at 3-month follow up between the groups. There was a close to significant tendency of lower mortality after placement of subperiosteal drainage system and a tendency towards lower rate of recurrent hematoma after placement of subdural drainage system. Our study shows for the first time a direct comparison of two mainly used surgical techniques in the treatment of scSDH. Both methods proved to be highly effective, and general patient data, complications, outcome and mortality of both groups are equal or superior compared with previously published series. Because there is a clear tendency to less mortality and fewer serious complications, treatment with double burr-hole trepanation, irrigation, and placement of subperiosteal drainage is our treatment of choice in patients with predictable high risk of complications. Copyright © 2012 Elsevier Inc. All rights reserved.

Characterization of accumulated precipitates during subsurface iron removal

KAUST Repository

Van Halem, Doris

2011-01-01

The principle of subsurface iron removal for drinking water supply is that aerated water is periodically injected into the aquifer through a tube well. On its way into the aquifer, the injected O2-rich water oxidizes adsorbed Fe 2+, creating a subsurface oxidation zone. When groundwater abstraction is resumed, the soluble Fe 2+ is adsorbed and water with reduced Fe concentrations is abstracted for multiple volumes of the injection water. In this article, Fe accumulation deposits in the aquifer near subsurface treatment wells were identified and characterized to assess the sustainability of subsurface iron removal regarding clogging of the aquifer and the potential co-accumulation of other groundwater constituents, such as As. Chemical extraction of soil samples, with Acid-Oxalate and HNO3, showed that Fe had accumulated at specific depths near subsurface iron removal wells after 12 years of operation. Whether it was due to preferred flow paths or geochemical mineralogy conditions; subsurface iron removal clearly favoured certain soil layers. The total Fe content increased between 11.5 and 390.8 mmol/kg ds in the affected soil layers, and the accumulated Fe was found to be 56-100% crystalline. These results suggest that precipitated amorphous Fe hydroxides have transformed to Fe hydroxides of higher crystallinity. These crystalline, compact Fe hydroxides have not noticeably clogged the investigated well and/or aquifer between 1996 and 2008. The subsurface iron removal wells even need less frequent rehabilitation, as drawdown increases more slowly than in normal production wells. Other groundwater constituents, such as Mn, As and Sr were found to co-accumulate with Fe. Acid extraction and ESEM-EDX showed that Ca occurred together with Fe and by X-ray Powder Diffraction it was identified as calcite. © 2010 Elsevier Ltd. All rights reserved.

Ultrasound guided transrectal catheter drainage of pelvic collections.

Science.gov (United States)

Thakral, Anuj; Sundareyan, Ramaniwas; Kumar, Sheo; Arora, Divya

2015-01-01

The transrectal approach to draining deep-seated pelvic collections may be used to drain The transrectal approach to draining deep-seated pelvic collections may be used to drain intra-abdominal collections not reached by the transabdominal approach. We discuss 6 patients with such pelvic collections treated with transrectal drainage using catheter placement via Seldinger technique. Transrectal drainage helped achieve clinical and radiological resolution of pelvic collections in 6 and 5 of 6 cases, respectively. It simultaneously helped avoid injury to intervening bowel loops and neurovascular structures using real-time visualization of armamentarium used for drainage. Radiation exposure from fluoroscopic/CT guidance was avoided. Morbidity and costs incurred in surgical exploration were reduced using this much less invasive ultrasound guided transrectal catheter drainage of deep-seated pelvic collections.

A Tree-Ring Reconstruction of the Salinity Gradient in the Northern Estuary of San Francisco Bay

Directory of Open Access Journals (Sweden)

David W. Stahle

2011-04-01

Full Text Available Blue oak tree-ring chronologies correlate highly with winter–spring precipitation totals over California, with Sacramento and San Joaquin river stream flow, and with seasonal variations in the salinity gradient in San Francisco Bay. The convergence of fresh and saline currents can influence turbidity, sediment accumulation, and biological productivity in the estuary. Three selected blue oak chronologies were used to develop a 625-year-long reconstruction of the seasonal salinity gradient, or low salinity zone (LSZ, which provides a unique perspective on the interannual-to-decadal variability of this important estuarine habitat indicator. The reconstruction was calibrated with instrumental LSZ data for the winter–spring season, and explains 73% of the variance in the February–June position of the LSZ from 1956 to 2003. Because this calibration period post-dates the sweeping changes that have occurred to land cover, channel morphology, and natural streamflow regimes in California, the reconstruction provides an idealized estimate for how the LSZ might have fluctuated under the seasonal precipitation variations of the past 625 years, given the modern geometry and bathymetry of the estuary and land cover across the drainage basin. The February–June season integrates precipitation and runoff variability during the cool season, and does not extend into the late-summer dry season when LSZ extremes can negatively affect Sacramento–San Joaquin Delta (Delta agriculture and some aquatic organisms. However, there is such strong inter-seasonal persistence in the instrumental LSZ data that precipitation totals during the cool season can strongly pre-condition LSZ position in late summer. The 625-year-long reconstruction indicates strong interannual and decadal variability, the frequent recurrence of consecutive 2-year LSZ maxima and minima, large-scale ocean atmospheric forcing, and an interesting asymmetrical influence of warm El Ni

Intermediate report on the problems of warm water drainage

International Nuclear Information System (INIS)

1976-01-01

The investigation into the solution of the problems of warm water drainage and its related matters was conducted, and the result was summarized by the warm water drainage sectional committee of the central public nuisance-prevention council entrusted by the Environment Agency. The first section of this report deals with the background of the warm water drainage problems. In December 1970, the environmental pollution prevention act was revised so as to include warm water drainage in the law. The second section deals with the progress of deliberation by the sectional committee. The third section deals with the actual conditions of warm water drainage. The temperature difference at the inlet and outlet of water was 5 to 11 0 C in power plants, 5 to 16 0 C in iron and steel works, 4 to 11 0 C in petroleum refineries, and 7 to 25 0 C in petrochemical plants. The amount of heat energy discharged from power plants was greater than that from the others. Other sections deal with its effects on the living things in water, the forecast of diffusion of warm drainage, the concept of the regulation of warm drainage, and the present countermeasure. Twelve points which require future investigation are listed. They are the change in the phases of living things affected by the change in temperature and flow of warm drainage, the effects on fishery resources, the estimation system for the environmental calorific capacity in the sea, the mechanism of diffusion and the forecasting method for the diffusion range. (Iwakiri, K.)

Dextrose saline compared with normal saline rehydration of hyperemesis gravidarum: a randomized controlled trial.

Science.gov (United States)

Tan, Peng Chiong; Norazilah, Mat Jin; Omar, Siti Zawiah

2013-02-01

To compare 5% dextrose-0.9% saline against 0.9% saline solution in the intravenous rehydration of hyperemesis gravidarum. Women at their first hospitalization for hyperemesis gravidarum were enrolled on admission to the ward and randomly assigned to receive either 5% dextrose-0.9% saline or 0.9% saline by intravenous infusion at a rate 125 mL/h over 24 hours in a double-blind trial. All participants also received thiamine and an antiemetic intravenously. Oral intake was allowed as tolerated. Primary outcomes were resolution of ketonuria and well-being (by 10-point visual numerical rating scale) at 24 hours. Nausea visual numerical rating scale scores were obtained every 8 hours for 24 hours. Persistent ketonuria rates after the 24-hour study period were 10 of 101 (9.9%) compared with 11 of 101 (10.9%) (P>.99; relative risk 0.9, 95% confidence interval 0.4-2.2) and median (interquartile range) well-being scores at 24 hours were 9 (8-10) compared with 9 (8-9.5) (P=.73) in the 5% dextrose-0.9% saline and 0.9% saline arms, respectively. Repeated measures analysis of variance of the nausea visual numerical rating scale score as assessed every 8 hours during the 24-hour study period showed a significant difference in favor of the 5% dextrose-0.9% saline arm (P=.046) with the superiority apparent at 8 and 16 hours, but the advantage had dissipated by 24 hours. Secondary outcomes of vomiting, resolution of hyponatremia, hypochloremia and hypokalemia, length of hospitalization, duration of intravenous antiemetic, and rehydration were not different. Intravenous rehydration with 5% dextrose-0.9% saline or 0.9% saline solution in women hospitalized for hyperemesis gravidarum produced similar outcomes. ISRCTN Register, www.controlled-trials.com/isrctn, ISRCTN65014409. I.

Contaminated environments in the subsurface and bioremediation: organic contaminants

OpenAIRE

Holliger, Christof; Gaspard, Sarra; Glod, Guy; Heijman, Cornelis; Schumacher, Wolfram; Schwarzenbach, René P.; Vazquez, Francisco

2017-01-01

Due to leakages, spills, improper disposal and accidents during transport, organic compounds have become subsurface contaminants that threaten important drinking water resources. One strategy to remediate such polluted subsurface environments is to make use of the degradative capacity of bacteria. It is often sufficient to supply the subsurface with nutrients such as nitrogen and phosphorus, and aerobic treatments are still dominating. However, anaerobic processes have advantages such as low ...

Development of laundry drainage treatment system with ceramic ultra filter

International Nuclear Information System (INIS)

Kanda, Masanori; Kurahasi, Takafumi

1995-01-01

A compact laundry drainage treatment system (UF system hereafter) with a ceramic ultra filter membrane (UF membrane hereafter) has been developed to reduce radioactivity in laundry drainage from nuclear power plants. The UF membrane is made of sintered fine ceramic. The UF membrane has 0.01 μm fine pores, resulting in a durable, heat-resistant, and corrosion-resistant porous ceramic filter medium. A cross-flow system, laundry drainage is filtrated while it flows across the UF membrane, is used as the filtration method. This method creates less caking when compared to other methods. The UF membrane is back washed at regular intervals with permeated water to minimize caking of the filter. The UF membrane and cross-flow system provides long stable filtration. The ceramic UF membrane is strong enough to concentrate suspended solids in laundry drainage up to a weight concentration of 10%. The final concentrated laundry drainage can be treated in an incinerator. The performance of the UF system was checked using radioactive laundry drainage. The decontamination factor of the UF system was 25 or more. The laundry drainage treatment capacity and concentration ratio of the UF system, as well as the service life of the UF membrane were also checked by examination using simulated non-radioactive laundry drainage. Even though laundry drainage was concentrated 1000 times, the UF system showed good permeated water quality and permeated water flux. (author)

Integrated Surface/subsurface flow modeling in PFLOTRAN

Energy Technology Data Exchange (ETDEWEB)

Painter, Scott L [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2016-10-01

Understanding soil water, groundwater, and shallow surface water dynamics as an integrated hydrological system is critical for understanding the Earth’s critical zone, the thin outer layer at our planet’s surface where vegetation, soil, rock, and gases interact to regulate the environment. Computational tools that take this view of soil moisture and shallow surface flows as a single integrated system are typically referred to as integrated surface/subsurface hydrology models. We extend the open-source, highly parallel, subsurface flow and reactive transport simulator PFLOTRAN to accommodate surface flows. In contrast to most previous implementations, we do not represent a distinct surface system. Instead, the vertical gradient in hydraulic head at the land surface is neglected, which allows the surface flow system to be eliminated and incorporated directly into the subsurface system. This tight coupling approach leads to a robust capability and also greatly simplifies implementation in existing subsurface simulators such as PFLOTRAN. Successful comparisons to independent numerical solutions build confidence in the approximation and implementation. Example simulations of the Walker Branch and East Fork Poplar Creek watersheds near Oak Ridge, Tennessee demonstrate the robustness of the approach in geometrically complex applications. The lack of a robust integrated surface/subsurface hydrology capability had been a barrier to PFLOTRAN’s use in critical zone studies. This work addresses that capability gap, thus enabling PFLOTRAN as a community platform for building integrated models of the critical zone.

Investigation of Lake Water Salinity by Using Four-Band Salinity Algorithm on WorldView-2 Satellite Image for a Saline Industrial Lake

Science.gov (United States)

Budakoǧlu, Murat; Karaman, Muhittin; Damla Uça Avcı, Z.; Kumral, Mustafa; Geredeli (Yılmaz), Serpil

2014-05-01

Salinity of a lake is an important characteristic since, these are potentially industrial lakes and the degree of salinity can significantly be used for determination of mineral resources and for the production management. In the literature, there are many studies of using satellite data for salinity related lake studies such as determination of salinity distribution and detection of potential freshwater sources in less salt concentrated regions. As the study area Lake Acigol, located in Denizli (Turkey) was selected. With it's saline environment, it's the major sodium sulphate production resource of Turkey. In this study, remote sensing data and data from a field study was used and correlated. Remote sensing is an efficient tool to monitor and analyze lake properties by using it complementary to field data. Worldview-2 satellite data was used in this study which consists of 8 bands. At the same time with the satellite data acquisition, a field study was conducted to collect the salinity values in 17 points of the laker with using YSI 556 Multiparametre for measurements. The values were measured as salinity amount in grams per kilogram solution and obtained as ppt unit. It was observed that the values vary from 34 ppt - 40.1 ppt and the average is 38.056 ppt. In Thalassic serie, the lake was in mixoeuhaline state in the time of issue. As a first step, ATCOR correction was performed on satellite image for atmospheric correction. There were some clouds on the lake field, hence it was decided to continue the study by using the 12 sampling points which were clear on the image. Then, for each sampling point, a spectral value was obtained by calculating the average at a 11*11 neighborhood. The relation between the spectral reflectance values and the salinity was investigated. The 4-band algorithm, which was used for determination of chlorophyll-a distribution in highly turbid coastal environment by Wei (2012) was applied. Salinity α (Λi-1 / Λj-1) * (Λk-1 / Λm-1) (i

Modular evaluation method for subsurface activities (MEMSA). A novel approach for integrating social acceptance in a permit decision-making process for subsurface activities

International Nuclear Information System (INIS)

Os, Herman W.A. van; Herber, Rien; Scholtens, Bert

2017-01-01

We investigate how the decision support system ‘Modular Evaluation Method Subsurface Activities’ (MEMSA) can help facilitate an informed decision-making process for permit applications of subsurface activities. To this end, we analyze the extent the MEMSA approach allows for a dialogue between stakeholders in a transparent manner. We use the exploration permit for the underground gas storage facility at the Pieterburen salt dome (Netherlands) as a case study. The results suggest that the MEMSA approach is flexible enough to adjust to changing conditions. Furthermore, MEMSA provides a novel way for identifying structural problems and possible solutions in permit decision-making processes for subsurface activities, on the basis of the sensitivity analysis of intermediate rankings. We suggest that the planned size of an activity should already be specified in the exploration phase, because this would allow for a more efficient use of the subsurface as a whole. We conclude that the host community should be involved to a greater extent and in an early phase of the permit decision-making process, for example, already during the initial analysis of the project area of a subsurface activity. We suggest that strategic national policy goals are to be re-evaluated on a regular basis, in the form of a strategic vision for the subsurface, to account for timing discrepancies between the realization of activities and policy deadlines, because this discrepancy can have a large impact on the necessity and therefore acceptance of a subsurface activity.

Modular evaluation method for subsurface activities (MEMSA). A novel approach for integrating social acceptance in a permit decision-making process for subsurface activities

Energy Technology Data Exchange (ETDEWEB)

Os, Herman W.A. van, E-mail: h.w.a.van.os@rug.nl [University of Groningen, Faculty of Mathematics and Natural Sciences, Geo-Energy, PO Box 800, 9700 AV Groningen (Netherlands); Herber, Rien, E-mail: rien.herber@rug.nl [University of Groningen, Faculty of Mathematics and Natural Sciences, Geo-Energy, PO Box 800, 9700 AV Groningen (Netherlands); Scholtens, Bert, E-mail: l.j.r.scholtens@rug.nl [University of Groningen, Faculty of Economics and Business, PO Box 800, 9700 AV Groningen (Netherlands)

2017-05-15

We investigate how the decision support system ‘Modular Evaluation Method Subsurface Activities’ (MEMSA) can help facilitate an informed decision-making process for permit applications of subsurface activities. To this end, we analyze the extent the MEMSA approach allows for a dialogue between stakeholders in a transparent manner. We use the exploration permit for the underground gas storage facility at the Pieterburen salt dome (Netherlands) as a case study. The results suggest that the MEMSA approach is flexible enough to adjust to changing conditions. Furthermore, MEMSA provides a novel way for identifying structural problems and possible solutions in permit decision-making processes for subsurface activities, on the basis of the sensitivity analysis of intermediate rankings. We suggest that the planned size of an activity should already be specified in the exploration phase, because this would allow for a more efficient use of the subsurface as a whole. We conclude that the host community should be involved to a greater extent and in an early phase of the permit decision-making process, for example, already during the initial analysis of the project area of a subsurface activity. We suggest that strategic national policy goals are to be re-evaluated on a regular basis, in the form of a strategic vision for the subsurface, to account for timing discrepancies between the realization of activities and policy deadlines, because this discrepancy can have a large impact on the necessity and therefore acceptance of a subsurface activity.

Electrode Cultivation and Interfacial Electron Transport in Subsurface Microorganisms

Science.gov (United States)

Karbelkar, A. A.; Jangir, Y.; Reese, B. K.; Wanger, G.; Anderson, C.; El-Naggar, M.; Amend, J.

2016-12-01

Continental subsurface environments can present significant energetic challenges to the resident microorganisms. While these environments are geologically diverse, potentially allowing energy harvesting by microorganisms that catalyze redox reactions, many of the abundant electron donors and acceptors are insoluble and therefore not directly bioavailable. Microbes can use extracellular electron transfer (EET) as a metabolic strategy to interact with redox active surfaces. This process can be mimicked on electrode surfaces and hence can lead to enrichment and quantification of subsurface microorganisms A primary bioelectrochemical enrichment with different oxidizing and reducing potentials set up in a single bioreactor was applied in situ to subsurface microorganisms residing in iron oxide rich deposits in the Sanford Underground Research Facility. Secondary enrichment revealed a plethora of classified and unclassified subsurface microbiota on both oxidizing and reducing potentials. From this enrichment, we have isolated a Gram-positive Bacillus along with Gram-negative Cupriavidus and Anaerospora strains (as electrode reducers) and Comamonas (as an electrode oxidizer). The Bacillus and Comamonas isolates were subjected to a detailed electrochemical characterization in half-reactors at anodic and cathodic potentials, respectively. An increase in cathodic current upon inoculation and cyclic voltammetry measurements confirm the hypothesis that Comamonas is capable of electron uptake from electrodes. In addition, measurements of Bacillus on anodes hint towards novel mechanisms that allow EET from Gram-positive bacteria. This study suggests that electrochemical approaches are well positioned to dissect such extracellular interactions that may be prevalent in the subsurface, while using physical electrodes to emulate the microhabitats, redox and geochemical gradients, and the spatially dependent interspecies interactions encountered in the subsurface. Electrochemical

Proceedings of the international land reclamation and mine drainage conference and third international conference on the abatement of acidic drainage. Volume 1: Mine drainage -- SP 06A-94

International Nuclear Information System (INIS)

Anon.

1994-01-01

Volume 1 of these proceedings is divided into the following sections: Modeling mine water quality; Water treatment with wetlands; Predicting mine water quality; Water treatment--Chemical; Control of acid mine drainage--Wet covers; Site characterization monitoring; Control of acid mine drainage--Alkaline addition; and Mine water geochemistry. Papers dealing with or applicable to coal or uranium mining have been processed separately for inclusion on the data base

Experimental measurements of the SP response to concentration and temperature gradients in sandstones with application to subsurface geophysical monitoring

Science.gov (United States)

Leinov, E.; Jackson, M. D.

2014-09-01

Exclusion-diffusion potentials arising from temperature gradients are widely neglected in self-potential (SP) surveys, despite the ubiquitous presence of temperature gradients in subsurface settings such as volcanoes and hot springs, geothermal fields, and oil reservoirs during production via water or steam injection. Likewise, with the exception of borehole SP logging, exclusion-diffusion potentials arising from concentration gradients are also neglected or, at best, it is assumed that the diffusion potential dominates. To better interpret these SP sources requires well-constrained measurements of the various coupling terms. We report measurements of thermoelectric and electrochemical exclusion-diffusion potentials across sandstones saturated with NaCl brine and find that electrode effects can dominate the measured voltage. After correcting for these, we find that Hittorf transport numbers are the same within experimental error regardless of whether ion transport occurs in response to temperature or concentration gradients over the range of NaCl concentration investigated that is typical of natural systems. Diffusion potentials dominate only if the pore throat radius is more than approximately 4000 times larger than the diffuse layer thickness. In fine-grained sandstones with small pore throat diameter, this condition is likely to be met only if the saturating brine is of relatively high salinity; thus, in many cases of interest to earth scientists, exclusion-diffusion potentials will comprise significant contributions from both ionic diffusion through, and ionic exclusion from, the pore space of the rock. However, in coarse-grained sandstones, or sandstones saturated with high-salinity brine, exclusion-diffusion potentials can be described using end-member models in which ionic exclusion is neglected. Exclusion-diffusion potentials in sandstones depend upon pore size and salinity in a complex way: they may be positive, negative, or zero depending upon sandstone

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

Science.gov (United States)

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

Numerical Three-Dimensional Model of Airport Terminal Drainage System

Directory of Open Access Journals (Sweden)

Strzelecki Michał

2014-03-01

Full Text Available During the construction of an airport terminal it was found that as a result of the hydrostatic pressure of underground water the foundation plate of the building had dangerously shifted in the direction opposite to that of the gravitational forces. The only effective measure was to introduce a drainage system on the site. The complex geology of the area indicated that two independent drainage systems, i.e., a horizontal system in the Quaternary beds and a vertical system in the Tertiary water-bearing levels, were necessary. This paper presents numerical FEM calculations of the two drainage systems being part of the airport terminal drainaged esign. The computer simulation which was carried out took into consideration the actual effect of the drainage systems and their impact on the depression cone being formed in the two aquifers.

Land drainage and restoration of land after NCB opencast mining

Energy Technology Data Exchange (ETDEWEB)

Bragg, N.

The author outlines the MAFF Field Drainage Research Unit's research into drainage of reinstated land. Current investigations have aimed at identifying the problems of reinstated soil and how they affect drainage design. Experiments on efficiency of permeable field drains and non-permeable field drains are mentioned. Further work is needed to examine long-term effects of storage on soil structure and whether existing drainage can be revitalised by secondary treatment.

30 CFR 250.119 - Will MMS approve subsurface gas storage?

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Will MMS approve subsurface gas storage? 250....119 Will MMS approve subsurface gas storage? The Regional Supervisor may authorize subsurface storage of gas on the OCS, on and off-lease, for later commercial benefit. To receive MMS approval you must...

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

Energy Technology Data Exchange (ETDEWEB)

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 regulation 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

Drainage Water Filtration

Science.gov (United States)

Tile drainage discharge from managed turf is known to carry elevated concentrations of agronomic fertilizers and chemicals. One approach being considered to reduce the transport is end-of-tile-filters. Laboratory and field studies have been initiated to address the efficacy of this approach. Result...

Salinity Trends in the Upper Colorado River Basin Upstream From the Grand Valley Salinity Control Unit, Colorado, 1986-2003

Science.gov (United States)

Leib, Kenneth J.; Bauch, Nancy J.

2008-01-01

In 1974, the Colorado River Basin Salinity Control Act was passed into law. This law was enacted to address concerns regarding the salinity content of the Colorado River. The law authorized various construction projects in selected areas or 'units' of the Colorado River Basin intended to reduce the salinity load in the Colorado River. One such area was the Grand Valley Salinity Control Unit in western Colorado. The U. S. Geological Survey has done extensive studies and research in the Grand Valley Salinity Control Unit that provide information to aid the U.S. Bureau of Reclamation and the Natural Resources Conservation Service in determining where salinity-control work may provide the best results, and to what extent salinity-control work was effective in reducing salinity concentrations and loads in the Colorado River. Previous studies have indicated that salinity concentrations and loads have been decreasing downstream from the Grand Valley Salinity Control Unit, and that the decreases are likely the result of salinity control work in these areas. Several of these reports; however, also document decreasing salinity loads upstream from the Grand Valley Salinity Control Unit. This finding was important because only a small amount of salinity-control work was being done in areas upstream from the Grand Valley Salinity Control Unit at the time the findings were reported (late 1990?s). As a result of those previous findings, the U.S. Bureau of Reclamation entered into a cooperative agreement with the U.S. Geological Survey to investigate salinity trends in selected areas bracketing the Grand Valley Salinity Control Unit and regions upstream from the Grand Valley Salinity Control Unit. The results of the study indicate that salinity loads were decreasing upstream from the Grand Valley Salinity Control Unit from 1986 through 2003, but the rates of decrease have slowed during the last 10 years. The average rate of decrease in salinity load upstream from the Grand Valley

Method of imaging the electrical conductivity distribution of a subsurface

Science.gov (United States)

Johnson, Timothy C.

2017-09-26

A method of imaging electrical conductivity distribution of a subsurface containing metallic structures with known locations and dimensions is disclosed. Current is injected into the subsurface to measure electrical potentials using multiple sets of electrodes, thus generating electrical resistivity tomography measurements. A numeric code is applied to simulate the measured potentials in the presence of the metallic structures. An inversion code is applied that utilizes the electrical resistivity tomography measurements and the simulated measured potentials to image the subsurface electrical conductivity distribution and remove effects of the subsurface metallic structures with known locations and dimensions.

Continuous 'Passive' Registration of Non-Point Contaminant Loads Via Agricultural Subsurface Drain Tubes

Science.gov (United States)

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 effect of climate change on urban drainage

DEFF Research Database (Denmark)

Grum, M.; Jørgensen, A.T.; Johansen, R.M.

2006-01-01

and consequences of climate change on urban drainage and urban runoff pollution issues. This study uses predictions from a regional climate model to look at the effects of climate change on extreme precipitation events. Results are presented in terms of point rainfall extremes. The analysis involves three steps......That we are in a period of extraordinary rates of climate change is today evident. These climate changes are likely to impact local weather conditions with direct impacts on precipitation patterns and urban drainage. In recent years several studies have focused on revealing the nature, extent...... to urban drainage. However, in spite of these uncertainties, and others raised in the discussion, the tendency is clear: extreme precipitation events effecting urban drainage and causing flooding will become more frequent as a result of climate change....

Impact of climate change on freshwater resources in a heterogeneous coastal aquifer of Bremerhaven, Germany: A three-dimensional modeling study.

Science.gov (United States)

Yang, Jie; Graf, Thomas; Ptak, Thomas

2015-01-01

Climate change is expected to induce sea level rise in the German Bight, which is part of the North Sea, Germany. Climate change may also modify river discharge of the river Weser flowing into the German Bight, which will alter both pressure and salinity distributions in the river Weser estuary. To study the long-term interaction between sea level rise, discharge variations, a storm surge and coastal aquifer flow dynamics, a 3D seawater intrusion model was designed using the fully coupled surface-subsurface numerical model HydroGeoSphere. The model simulates the coastal aquifer as an integral system considering complexities such as variable-density flow, variably saturated flow, irregular boundary conditions, irregular land surface and anthropogenic structures (e.g., dyke, drainage canals, water gates). The simulated steady-state groundwater flow of the year 2009 is calibrated using PEST. In addition, four climate change scenarios are simulated based on the calibrated model: (i) sea level rise of 1m, (ii) the salinity of the seaside boundary increases by 4 PSU (Practical Salinity Units), (iii) the salinity of the seaside boundary decreases by 12 PSU, and (iv) a storm surge with partial dyke failure. Under scenarios (i) and (iv), the salinized area expands several kilometers further inland during several years. Natural remediation can take up to 20 years. However, sudden short-term salinity changes in the river Weser estuary do not influence the salinized area in the coastal aquifer. The obtained results are useful for coastal engineering practices and drinking water resource management. Copyright © 2015 Elsevier B.V. All rights reserved.

Systematic review and meta-analysis of closed suction drainage versus non-drainage in primary hip arthroplasty.

LENUS (Irish Health Repository)

Kelly, Enda G

2014-03-01

The routine use of drains in surgery has been dogmatically instituted in some disciplines. Orthopaedic surgery is one such sub-speciality. The use of postoperative closed suction drainage in total hip arthroplasty (THA) has become increasingly controversial with multiple randomised control trials performed to assess the benefit to outcome in THA. The hypothesis of this systematic review is that closed suction drainage does not infer a benefit and increase transfusion requirements of primary total hip arthroplasty patients. A systematic review and meta-analysis was conducted adhering to the PRISMA guidelines. A search of the available literature was performed on PubMed, Cochrane Central Registry of Controlled Trials, MEDLINE (OVID) and EMBASE using a combination of MeSH terms and Boolean operators. All data analysis was performed using the Cochrane Collaboration\\'s Review Manager 5.1. Sixteen studies (n=2705) were included in the analysis. Post-operative closed suction drainage was found to increase total blood loss and blood transfusion requirements (p<0.05). Surgical site infection demonstrated no significant difference between the two groups (p=0.82). No significant difference in haematoma formation between groups (p=0.19) was elicited. The routine use of closed suction drainage systems post primary hip arthroplasty is not supported by this meta-analysis. However, the heterogeneity between studies does limit the accuracy of the meta-analysis.

Spatial variations in water composition at a northern Canadian lake impacted by mine drainage

International Nuclear Information System (INIS)

Moncur, M.C.; Ptacek, C.J.; Blowes, D.W.; Jambor, J.L.

2006-01-01

Release of acid drainage from mine-waste disposal areas is a problem of international scale. Contaminated surface water, derived from mine wastes, originates both as direct surface runoff and, indirectly, as subsurface groundwater flow. At Camp Lake, a small Canadian Shield lake that is in northern Manitoba and is ice-covered 6 months of the year, direct and indirect release of drainage from an adjacent sulfide-rich tailings impoundment has severely affected the quality of the lake water. Concentrations of the products from sulfide oxidation are extremely high in the pore waters of the tailings impoundment. Groundwater and surface water derived from the impoundment discharge into a semi-isolated shallow bay in Camp Lake. The incorporation of this aqueous effluent has altered the composition of the lake water, which in turn has modified the physical limnology of the lake. Geochemical profiles of the water column indicate that, despite its shallow depth (6 m), the bay is stratified throughout the year. The greatest accumulation of dissolved metals and SO 4 is in the lower portion of the water column, with concentrations up to 8500 mg L -1 Fe, 20,000 mg L -1 SO 4 , 30 mg L -1 Zn, 100 mg L -1 Al, and elevated concentrations of Cu, Cd, Pb and Ni. Meromictic conditions and very high solute concentrations are limited to the bay. Outside the bay, solute concentrations are lower and some stratification of the water column exists. Identification of locations and composition of groundwater discharge relative to lake bathymetry is a fundamental aspect of understanding chemical evolution and physical stability of mine-impacted lakes

Geochemical characterization of subsurface sediments in the Netherlands

NARCIS (Netherlands)

Huisman, D.J.

1998-01-01

Traditionally, the Netherlands' subsurface is mainly used to obtain good quality drinking and industrial waters from the different aquifers. Due to the lack of space on the surface, increasing environmental problems and demand for energy, the subsurface will be used increasingly for other

A model to measure lymphatic drainage from the eye.

Science.gov (United States)

Kim, Minhui; Johnston, Miles G; Gupta, Neeru; Moore, Sara; Yücel, Yeni H

2011-11-01

Intraocular pressure (IOP) is the most important risk factor for glaucoma development and progression. Most anti-glaucoma treatments aim to lower IOP by enhancing aqueous humor drainage from the eye. Aqueous humor drainage occurs via well-characterized trabecular meshwork (TM) and uveoscleral (UVS) pathways, and recently described ciliary body lymphatics. The relative contribution of the lymphatic pathway to aqueous drainage is not known. We developed a sheep model to quantitatively assess lymphatic drainage along with TM and UVS outflows. This study describes that model and presents our initial findings. Following intracameral injection of (125)I-bovine serum albumin (BSA), lymph was continuously collected via cannulated cervical lymphatic vessels and the thoracic lymphatic duct over either a 3-h or 5-h time period. In the same animals, blood samples were collected from the right jugular vein every 15 min. Lymphatic and TM drainage were quantitatively assessed by measuring (125)I-BSA in lymph and plasma, respectively. Radioactive tracer levels were also measured in UVS and "other" ocular tissue, as well as periocular tissue harvested 3 and 5 h post-injection. Tracer recovered from UVS tissue was used to estimate UVS drainage. The amount of (125)I-BSA recovered from different fluid and tissue compartments was expressed as a percentage of total recovered tracer. Three hours after tracer injection, percentage of tracer recovered in lymph and plasma was 1.64% ± 0.89% and 68.86% ± 9.27%, respectively (n = 8). The percentage of tracer in UVS, other ocular and periocular tissues was 19.87% ± 5.59%, 4.30% ± 3.31% and 5.32% ± 2.46%, respectively. At 5 h (n = 2), lymphatic drainage was increased (6.40% and 4.96% vs. 1.64%). On the other hand, the percentage of tracer recovered from UVS and other ocular tissue had decreased, and the percentage from periocular tissue showed no change. Lymphatic drainage increased steadily over the 3 h post-injection period, while TM

Electrical Subsurface Grounding Analysis

International Nuclear Information System (INIS)

J.M. Calle

2000-01-01

The purpose and objective of this analysis is to determine the present grounding requirements of the Exploratory Studies Facility (ESF) subsurface electrical system and to verify that the actual grounding system and devices satisfy the requirements

Saline agriculture in Mediterranean environments

Directory of Open Access Journals (Sweden)

Albino Maggio

2011-03-01

Full Text Available Salinization is increasingly affecting world's agricultural land causing serious yield loss and soil degradation. Understanding how we could improve crop productivity in salinized environments is therefore critical to meet the challenging goal of feeding 9.3 billion people by 2050. Our comprehension of fundamental physiological mechanisms in plant salt stress adaptation has greatly advanced over the last decades. However, many of these mechanisms have been linked to salt tolerance in simplified experimental systems whereas they have been rarely functionally proven in real agricultural contexts. In-depth analyses of specific crop-salinity interactions could reveal important aspects of plant salt stress adaptation as well as novel physiological/agronomic targets to improve salinity tolerance. These include the developmental role of root vs. shoot systems respect to water-ion homeostasis, morphological vs. metabolic contributions to stress adaptation, developmental processes vs. seasonal soil salinity evolution, residual effects of saline irrigation in non-irrigated crops, critical parameters of salt tolerance in soil-less systems and controlled environments, response to multiple stresses. Finally, beneficial effects of salinization on qualitative parameters such as stress-induced accumulation of high nutritional value secondary metabolites should be considered, also. In this short review we attempted to highlight the multifaceted nature of salinity in Mediterranean agricultural systems by summarizing most experimental activity carried out at the Department of Agricultural Engineering and Agronomy of University of Naples Federico II in the last few years.

Regulated Electric Drainage and its Interference with Track Circuits

Directory of Open Access Journals (Sweden)

Vaclav Kolar

2018-01-01

Full Text Available Electric drainage is a power electronic device used to protect underground metal devices (such as piping from the corrosive effects of stray currents. Stray currents are usually caused by DC electric traction, such as trams or railways. In places where stray currents leave the underground device and return into rails, they cause significant electrochemical corrosion of buried devices. The principle of electric drainage is based on electrical connection between the underground device and electric traction rails, which ensures that current flows through this connection, instead of flowing into the ground. Nowadays, the most widely used type is regulated electric drainage, where current is regulated by means of Pulse Width Modulation (PWM. Because of this modulation, current flowing through the drainage contains harmonic components with different frequencies. In modern railways, track circuits are often used as an important part of the track security system. For safe operation, it is necessary to ensure that frequencies generated by the drainage do not interfere with track circuits. This paper describes the design of a regulated drainage control system, with regard to its compatibility with track circuits and this paper contains related computer simulations and discussion of the results

Radiologic guidance of drainage of infected and noninfected thoracic fluid collections

International Nuclear Information System (INIS)

Van Sonnenberg, E.; Casola, G.; Stavas, J.; Neff, C.C.; Wittich, G.R.; Varney, R.A.; Christensen, R.; Friedman, P.

1987-01-01

This exhibit illustrates the spectrum and benefits of radiologic guidance of drainage of 100 thoracic fluid collections. Collections which underwent drainage include: empyemas, lung abscesses, bronchopleural fistulas (BPF), mediastinal abscesses, paracardial collections, bronchogenic cysts, sequestrations, lymphocoeles, malignant effusions, and necrotic tumors. Sclerotherapy catheterization also is described. The modalities for guidance were CT, US, and fluoroscopy. Inadequate thoracostomy tube drainage occurred in a third of the patients prior to radiologic drainage. Drainages were effective in 85% of cases sparing surgery or another thoracostomy tube. Complications occurred in 7% of patients, most being minor and none requiring operation. Pitfalls and caveats are highlighted. Criteria for drainage of lung abscesses and BPF are emphasized, as are techniques and methods of follow-up

Acid mine drainage

Science.gov (United States)

Bigham, Jerry M.; Cravotta, Charles A.

2016-01-01

Acid mine drainage (AMD) consists of metal-laden solutions produced by the oxidative dissolution of iron sulfide minerals exposed to air, moisture, and acidophilic microbes during the mining of coal and metal deposits. The pH of AMD is usually in the range of 2–6, but mine-impacted waters at circumneutral pH (5–8) are also common. Mine drainage usually contains elevated concentrations of sulfate, iron, aluminum, and other potentially toxic metals leached from rock that hydrolyze and coprecipitate to form rust-colored encrustations or sediments. When AMD is discharged into surface waters or groundwaters, degradation of water quality, injury to aquatic life, and corrosion or encrustation of engineered structures can occur for substantial distances. Prevention and remediation strategies should consider the biogeochemical complexity of the system, the longevity of AMD pollution, the predictive power of geochemical modeling, and the full range of available field technologies for problem mitigation.

Risk factors influencing the pleural drainage volume after transthoracic oesophagectomy.

Science.gov (United States)

Kosugi, Shin-ichi; Kanda, Tatsuo; Yajima, Kazuhito; Ishikawa, Takashi; Sakamoto, Kaoru

2013-06-01

The objective of this study was to clarify the factors influencing pleural drainage volume after transthoracic oesophagectomy and to determine criteria for the selection of patients who would benefit from the early removal of chest drains. Clinicopathological characteristics of 155 patients who underwent transthoracic oesophagectomy were prospectively collected, and the daily drainage volume of each patient was retrospectively reviewed. Potential risk factors were compared between the high-output group (n = 39) and low-output group (n = 116), which were dichotomized using the 75th percentile of total pleural drainage volume of the total study population. Multivariate logistic regression analyses were used to identify independent risk factors. The median duration of drainage was 10 days, with a median total drainage volume of 2258 ml. Of 27 potential risk factors influencing the drainage volume, creatinine clearance (P = 0.04), operative approach (P = 0.03) and thoracic duct removal (P = 0.01) were significantly associated with the total pleural drainage volume. The removal of the thoracic duct (P = 0.02; odds ratio, 4.02; 95% confidence interval 1.20-13.41) and lower creatinine clearance (P = 0.04; odds ratio, 1.02; 95% confidence interval 1.00-1.04) was independent risk factors for increased pleural drainage volume after transthoracic oesophagectomy. The early removal of chest drains may be possible in patients without these risk factors.

Estimating the benefits of improved drainage on pavement ...

African Journals Online (AJOL)

user

2 Centre for Transportation Systems, Indian Institute of Technology Roorkee, INDIA ... parking lots that only allow cars, not trucks). ..... drainage section) and 2015 & 2019 (for poor drainage section) after the construction of an overlay, it was ...

Acid Mine Drainage Treatment

National Research Council Canada - National Science Library

Fripp, Jon

2000-01-01

.... Acid mine drainage (AMD) can have severe impacts to aquatic resources, can stunt terrestrial plant growth and harm wetlands, contaminate groundwater, raise water treatment costs, and damage concrete and metal structures...

Agricultural Drainage Well Intakes

Data.gov (United States)

Iowa State University GIS Support and Research Facility — Locations of surface intakes for registered agriculture drainage wells according to the database maintained by IDALS. Surface intakes were located from their...

N2-fixation in fababean (vicia faba l.) grown in saline and non saline conditions using 15N tracer technique

International Nuclear Information System (INIS)

Khalifa, Kh.; Kurdali, F.

2002-09-01

A pot experiment was conducted to study the performance of growing fababean and barley under saline conditions, in terms of, dry matter yield, total nitrogen and, percentages and amount of N derived from soil, fertilizer and atmosphere using 15 N isotope dilution method. Three saline treatments were performed: First, plants were grown in saline soil and irrigated with saline water (Ws Ss), Second, Plants were grown in saline soil and irrigated with saline water (Ws Ss); and Third, Plants grown in non saline soil and irrigated with saline water (Ws Sn). Furthermore, a control treatment was performed by using non-saline soil and non-saline water (Wn Sn). The different salinity treatments reduced plant growth and the reduction was more pronounced in fababean than in barley. However, under conditions of either saline soil-soft irrigation water or non saline soil-salty irrigation water, the relative growth reduction did not exceed 50% of the control; whereas, a significant negative effect was obtained when plants were grown under completely saline conditions of both soil and irrigation water. Percentage of N 2 -fixed (% Ndfa) was not negatively affected by saline conditions. However, our results clearly demonstrated that the effect of salinity in fababean was more evident on plant growth than on N 2 -fixing activity. Further studies are needed to obtain more salt tolerant faba bean genotypes in terms of growth and yield. This could be simultaneously improve yield and N 2 -fixation under sever saline conditions. (author)

CT-guided biopsies and drainage

International Nuclear Information System (INIS)

Scheppers, I.; Wollschlaeger, D.

2011-01-01

Following the implementation of computed tomography (CT) or ultrasound-guided biopsy of solid tumors and the puncture and drainage of liquid processes, the number of surgical open biopsies and curative operations for abscess drainage has declined. Such CT-guided interventions are performed in nearly every organ. Instead of aspiration biopsies, more and more core biopsies are being performed to allow histopathological evaluation and thus allowing targeted therapy. This article is intended to give a general overview of techniques, materials, indications and contraindications. Ultrasound-guided biopsies as well as large bore vacuum biopsies of the breast are not included in this review. (orig.) [de

Management of chest drainage tubes after lung surgery.

Science.gov (United States)

Satoh, Yukitoshi

2016-06-01

Since chest tubes have been routinely used to drain the pleural space, particularly after lung surgery, the management of chest tubes is considered to be essential for the thoracic surgeon. The pleural drainage system requires effective drainage, suction, and water-sealing. Another key point of chest tube management is that a water seal is considered to be superior to suction for most air leaks. Nowadays, the most common pleural drainage device attached to the chest tube is the three-bottle system. An electronic chest drainage system has been developed that is effective in standardizing the postoperative management of chest tubes. More liberal use of digital drainage devices in the postoperative management of the pleural space is warranted. The removal of chest tubes is a common procedure occurring almost daily in hospitals throughout the world. Extraction of the tube is usually done at the end of full inspiration or at the end of full expiration. The tube removal technique is not as important as how it is done and the preparation for the procedure. The management of chest tubes must be based on careful observation, the patient's characteristics, and the operative procedures that had been performed.

Drainage from coal mines: Chemistry and environmental problems

International Nuclear Information System (INIS)

Wildeman, T.

1991-01-01

Much of the research on coal-mine drainage chemistry was conducted a decade ago, and now increased environmental awareness has brought about renewed interest in the findings. Consideration of the trace minerals and elements in coal points to the possible generation of acidic waters upon weathering, especially when pyrite is present. When pyrite weathers, it produces H + and Fe 3+ which catalyze the incongruent weathering of other carbonates and sulfides. In this weathering mechanism, catalysis by bacteria is important. Of the environmental problems in coal mine drainage, the mineral acidity of the water is the most serious. This is caused not only by the H + , but also by Mn 4+ , Fe 3+ , and Al 3+ that are found or generated within the drainage. Case studies in Kentucky, Pennsylvania, Illinois, and Colorado show that the abundance and form of pyrite in the deposit and in the overburden determines the level of acidity and the concentration of heavy metal pollutants in the drainage. Recent trends in environmental enforcement that emphasize integrated stream water standards and biotoxicity assays point to the possibility that the concentrations of heavy metals in coal mine drainages may cause environmental concern

Glaucoma Drainage Device Erosion Following Ptosis Surgery.

Science.gov (United States)

Bae, Steven S; Campbell, Robert J

2017-09-01

To highlight the potential risk of glaucoma drainage device erosion following ptosis surgery. Case report. A 71-year-old man underwent uncomplicated superotemporal Ahmed glaucoma valve implantation in the left eye in 2008. Approximately 8 years later, the patient underwent bilateral ptosis repair, which successfully raised the upper eyelid position. Three months postoperatively, the patient's glaucoma drainage implant tube eroded through the corneal graft tissue and overlying conjunctiva to become exposed. A graft revision surgery was successfully performed with no further complications. Caution and conservative lid elevation may be warranted when performing ptosis repair in patients with a glaucoma drainage implant, and patients with a glaucoma implant undergoing ptosis surgery should be followed closely for signs of tube erosion.

Scenario simulation based assessment of subsurface energy storage

Science.gov (United States)

Beyer, C.; Bauer, S.; Dahmke, A.

2014-12-01

Energy production from renewable sources such as solar or wind power is characterized by temporally varying power supply. The politically intended transition towards renewable energies in Germany („Energiewende") hence requires the installation of energy storage technologies to compensate for the fluctuating production. In this context, subsurface energy storage represents a viable option due to large potential storage capacities and the wide prevalence of suited geological formations. Technologies for subsurface energy storage comprise cavern or deep porous media storage of synthetic hydrogen or methane from electrolysis and methanization, or compressed air, as well as heat storage in shallow or moderately deep porous formations. Pressure build-up, fluid displacement or temperature changes induced by such operations may affect local and regional groundwater flow, geomechanical behavior, groundwater geochemistry and microbiology. Moreover, subsurface energy storage may interact and possibly be in conflict with other "uses" like drinking water abstraction or ecological goods and functions. An utilization of the subsurface for energy storage therefore requires an adequate system and process understanding for the evaluation and assessment of possible impacts of specific storage operations on other types of subsurface use, the affected environment and protected entities. This contribution presents the framework of the ANGUS+ project, in which tools and methods are developed for these types of assessments. Synthetic but still realistic scenarios of geological energy storage are derived and parameterized for representative North German storage sites by data acquisition and evaluation, and experimental work. Coupled numerical hydraulic, thermal, mechanical and reactive transport (THMC) simulation tools are developed and applied to simulate the energy storage and subsurface usage scenarios, which are analyzed for an assessment and generalization of the imposed THMC

Dynamic drainage of froth with wood fibers

Science.gov (United States)

J.Y. Zhu; Freya Tan

2005-01-01

Understanding froth drainage with fibers (or simply called fiber drainage in froth) is important for improving fiber yield in the flotation deinking operation. In this study, the data of water and fiber mass in foams collected at different froth heights were used to reconstruct the time dependent and spatially resolved froth density and fiber volumetric concentration...

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

Science.gov (United States)

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 (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.

Intermediate-term and long-term outcome of piggyback drainage: connecting glaucoma drainage device to a device in-situ for improved intraocular pressure control.

Science.gov (United States)

Dervan, Edward; Lee, Edward; Giubilato, Antonio; Khanam, Tina; Maghsoudlou, Panayiotis; Morgan, William H

2017-11-01

This study provides results of a treatment option for patients with failed primary glaucoma drainage device. The study aimed to describe and evaluate the long-term intraocular pressure control and complications of a new technique joining a second glaucoma drainage device directly to an existing glaucoma drainage device termed 'piggyback drainage'. This is a retrospective, interventional cohort study. Eighteen eyes of 17 patients who underwent piggyback drainage between 2004 and 2013 inclusive have been studied. All patients had prior glaucoma drainage device with uncontrolled intraocular pressure. The piggyback technique involved suturing a Baerveldt (250 or 350 mm) or Molteno3 glaucoma drainage device to an unused scleral quadrant and connecting the silicone tube to the primary plate bleb. Failure of intraocular pressure control defined as an intraocular pressure greater than 21 mmHg on maximal therapy on two separate occasions or further intervention to control intraocular pressure. The intraocular pressure was controlled in seven eyes (39%) at last follow-up with a mean follow-up time of 74.2 months. The mean preoperative intraocular pressure was 27.1 mmHg (95% confidence interval 23.8-30.3) compared with 18.4 mmHg (95% confidence interval 13.9-22.8) at last follow-up. The mean time to failure was 57.1 months (95% confidence interval 32.2-82), and the mean time to further surgery was 72.3 months (95% confidence interval 49.9-94.7). Lower preoperative intraocular pressure was associated with longer duration of intraocular pressure control (P = 0.048). If the intraocular pressure was controlled over 2 years, it continued to be controlled over the long term. Two eyes (11%) experienced corneal decompensation. Piggyback drainage represents a viable surgical alternative for the treatment of patients with severe glaucoma with failing primary glaucoma drainage device, particularly in those at high risk of corneal decompensation. © 2017 Royal Australian and New Zealand

An optimization model to design and manage subsurface drip irrigation system for alfalfa

Science.gov (United States)

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.

Streamflow distribution maps for the Cannon River drainage basin, southeast Minnesota, and the St. Louis River drainage basin, northeast Minnesota

Science.gov (United States)

Smith, Erik A.; Sanocki, Chris A.; Lorenz, David L.; Jacobsen, Katrin E.

2017-12-27

Streamflow distribution maps for the Cannon River and St. Louis River drainage basins were developed by the U.S. Geological Survey, in cooperation with the Legislative-Citizen Commission on Minnesota Resources, to illustrate relative and cumulative streamflow distributions. The Cannon River was selected to provide baseline data to assess the effects of potential surficial sand mining, and the St. Louis River was selected to determine the effects of ongoing Mesabi Iron Range mining. Each drainage basin (Cannon, St. Louis) was subdivided into nested drainage basins: the Cannon River was subdivided into 152 nested drainage basins, and the St. Louis River was subdivided into 353 nested drainage basins. For each smaller drainage basin, the estimated volumes of groundwater discharge (as base flow) and surface runoff flowing into all surface-water features were displayed under the following conditions: (1) extreme low-flow conditions, comparable to an exceedance-probability quantile of 0.95; (2) low-flow conditions, comparable to an exceedance-probability quantile of 0.90; (3) a median condition, comparable to an exceedance-probability quantile of 0.50; and (4) a high-flow condition, comparable to an exceedance-probability quantile of 0.02.Streamflow distribution maps were developed using flow-duration curve exceedance-probability quantiles in conjunction with Soil-Water-Balance model outputs; both the flow-duration curve and Soil-Water-Balance models were built upon previously published U.S. Geological Survey reports. The selected streamflow distribution maps provide a proactive water management tool for State cooperators by illustrating flow rates during a range of hydraulic conditions. Furthermore, after the nested drainage basins are highlighted in terms of surface-water flows, the streamflows can be evaluated in the context of meeting specific ecological flows under different flow regimes and potentially assist with decisions regarding groundwater and surface

How secure is subsurface CO2 storage? Controls on leakage in natural CO2 reservoirs

Science.gov (United States)

Miocic, Johannes; Gilfillan, Stuart; McDermott, Christopher; Haszeldine, Stuart

2014-05-01

Carbon Capture and Storage (CCS) is the only industrial scale technology available to directly reduce carbon dioxide (CO2) emissions from fossil fuelled power plants and large industrial point sources to the atmosphere. The technology includes the capture of CO2 at the source and transport to subsurface storage sites, such as depleted hydrocarbon reservoirs or saline aquifers, where it is injected and stored for long periods of time. To have an impact on the greenhouse gas emissions it is crucial that there is no or only a very low amount of leakage of CO2 from the storage sites to shallow aquifers or the surface. CO2 occurs naturally in reservoirs in the subsurface and has often been stored for millions of years without any leakage incidents. However, in some cases CO2 migrates from the reservoir to the surface. Both leaking and non-leaking natural CO2 reservoirs offer insights into the long-term behaviour of CO2 in the subsurface and on the mechanisms that lead to either leakage or retention of CO2. Here we present the results of a study on leakage mechanisms of natural CO2 reservoirs worldwide. We compiled a global dataset of 49 well described natural CO2 reservoirs of which six are leaking CO2 to the surface, 40 retain CO2 in the subsurface and for three reservoirs the evidence is inconclusive. Likelihood of leakage of CO2 from a reservoir to the surface is governed by the state of CO2 (supercritical vs. gaseous) and the pressure in the reservoir and the direct overburden. Reservoirs with gaseous CO2 is more prone to leak CO2 than reservoirs with dense supercritical CO2. If the reservoir pressure is close to or higher than the least principal stress leakage is likely to occur while reservoirs with pressures close to hydrostatic pressure and below 1200 m depth do not leak. Additionally, a positive pressure gradient from the reservoir into the caprock averts leakage of CO2 into the caprock. Leakage of CO2 occurs in all cases along a fault zone, indicating that

Heating systems for heating subsurface formations

Science.gov (United States)

Nguyen, Scott Vinh [Houston, TX; Vinegar, Harold J [Bellaire, TX

2011-04-26

Methods and systems for heating a subsurface formation are described herein. A heating system for a subsurface formation includes a sealed conduit positioned in an opening in the formation and a heat source. The sealed conduit includes a heat transfer fluid. The heat source provides heat to a portion of the sealed conduit to change phase of the heat transfer fluid from a liquid to a vapor. The vapor in the sealed conduit rises in the sealed conduit, condenses to transfer heat to the formation and returns to the conduit portion as a liquid.

Properties of the subglacial till inferred from supraglacial lake drainage

Science.gov (United States)

Neufeld, J. A.; Hewitt, D.

2017-12-01

The buildup and drainage of supraglacial lakes along the margins of the Greenland ice sheet has been previously observed using detailed GPS campaigns which show that rapid drainage events are often preceded by localised, transient uplift followed by rapid, and much broader scale, uplift and flexure associated with the main drainage event [1,2]. Previous models of these events have focused on fracturing during rapid lake drainage from an impermeable bedrock [3] or a thin subglacial film [4]. We present a new model of supraglacial drainage that couples the water flux from rapid lake drainage events to a simplified model of the pore-pressure in a porous, subglacial till along with a simplified model of the flexure of glacial ice. Using a hybrid mathematical model we explore the internal transitions between turbulent and laminar flow throughout the evolving subglacial cavity and porous till. The model predicts that an initially small water flux may locally increase pore-pressure in the till leading to uplift and a local divergence in the ice velocity that may ultimately be responsible for large hydro-fracturing and full-scale drainage events. Furthermore, we find that during rapid drainage while the presence of a porous, subglacial till is crucial for propagation, the manner of spreading is remarkably insensitive to the properties of the subglacial till. This is in stark contrast to the post-drainage relaxation of the pore pressure, and hence sliding velocity, which is highly sensitive to the permeability, compressibility and thickness of subglacial till. We use our model, and the inferred sensitivity to the properties of the subglacial till after the main drainage event, to infer the properties of the subglacial till. The results suggest that a detailed interpretation of supraglacial lake drainage may provide important insights into the hydrology of the subglacial till along the margins of the Greenland ice sheet, and the coupling of pore pressure in subglacial till