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Sample records for soil petrophysical parameters

  1. Methods for estimating petrophysical parameters from well logs in tight oil reservoirs: a case study

    NASA Astrophysics Data System (ADS)

    Zhao, Peiqiang; Zhuang, Wen; Sun, Zhongchun; Wang, Zhenlin; Luo, Xingping; Mao, Zhiqiang; Tong, Zemin

    2016-02-01

    Estimating petrophysical parameters from well logs plays a significant role in the exploration and development of tight oil resources, but faces challenges. What’s more, the methods for petrophysical parameters from well logs are paid little attention at present. In this paper, the typical tight oil reservoirs of Northwest China are used as an example. Based on the characteristics of mineralogy and fluids in the study field, the rock is assumed into five components which are clays, quartz and feldspar, carbonates, kerogen and pore fluids (porosity). The sum of kerogen content and porosity is defined as the apparent porosity. Then, two porosity log response equations are established. Once the clay content is determined by an individual method, the quartz and feldspar content, carbonate content and apparent porosity are calculated through the established equations. The kerogen content is the difference of the apparent porosity and porosity from nuclear magnetic resonance (NMR) logs. This paper also presents a new approach that combines the complex refractive index method (CRIM) and pseudo Archie method to compute saturation from dielectric logs, which avoids selection for the dielectric constants of each of the minerals. The effectiveness and reliability of these methods are verified by the successful application in the study of the target tight oil play in Northwest China.

  2. Sensitivity of injection costs to input petrophysical parameters in numerical geologic carbon sequestration models

    SciTech Connect

    Cheng, C. L.; Gragg, M. J.; Perfect, E.; White, Mark D.; Lemiszki, P. J.; McKay, L. D.

    2013-08-24

    Numerical simulations are widely used in feasibility studies for geologic carbon sequestration. Accurate estimates of petrophysical parameters are needed as inputs for these simulations. However, relatively few experimental values are available for CO2-brine systems. Hence, a sensitivity analysis was performed using the STOMP numerical code for supercritical CO2 injected into a model confined deep saline aquifer. The intrinsic permeability, porosity, pore compressibility, and capillary pressure-saturation/relative permeability parameters (residual liquid saturation, residual gas saturation, and van Genuchten alpha and m values) were varied independently. Their influence on CO2 injection rates and costs were determined and the parameters were ranked based on normalized coefficients of variation. The simulations resulted in differences of up to tens of millions of dollars over the life of the project (i.e., the time taken to inject 10.8 million metric tons of CO2). The two most influential parameters were the intrinsic permeability and the van Genuchten m value. Two other parameters, the residual gas saturation and the residual liquid saturation, ranked above the porosity. These results highlight the need for accurate estimates of capillary pressure-saturation/relative permeability parameters for geologic carbon sequestration simulations in addition to measurements of porosity and intrinsic permeability.

  3. Resolution dependence of petrophysical parameters derived from X-ray tomography of chalk

    SciTech Connect

    Müter, D.; Sørensen, H. O.; Jha, D.; Harti, R.; Dalby, K. N.; Stipp, S. L. S.; Suhonen, H.; Feidenhans'l, R.; Engstrøm, F.

    2014-07-28

    X-ray computed tomography data from chalk drill cuttings were taken over a series of voxel dimensions, ranging from 320 to 25 nm. From these data sets, standard petrophysical parameters (porosity, surface area, and permeability) were derived and we examined the effect of the voxel dimension (i.e., image resolution) on these properties. We found that for the higher voxel dimensions, they are severely over or underestimated, whereas for 50 and 25 nm voxel dimension, the resulting values (5%–30% porosity, 0.2–2 m{sup 2}/g specific surface area, and 0.06–0.34 mD permeability) are within the expected range for this type of rock. We compared our results to macroscopic measurements and in the case of surface area, also to measurements using the Brunauer-Emmett-Teller (BET) method and found that independent of the degree of compaction, the results from tomography amount to about 30% of the BET method. Finally, we concluded that at 25 nm voxel dimension, the essential features of the nanoscopic pore network in chalk are captured but better resolution is still needed to derive surface area.

  4. Petrophysical database of Uganda

    NASA Astrophysics Data System (ADS)

    Ruotoistenmäki, Tapio; Birungi, Nelson R.

    2015-06-01

    The petrophysical database of Uganda contains data on ca. 5800 rock samples collected and analyzed during 2009-2012 in international geological and geophysical projects covering the main part of the land area of Uganda. The parameters included are the susceptibilities and densities of all available field samples. Susceptibilities were measured from the samples from three directions. Using these parameters, we also calculated the ratios of susceptibility maxima/minima reflecting direction homogeneity of magnetic minerals, and estimated the iron content of paramagnetic samples and the magnetite content of ferrimagnetic samples. Statistical and visual analysis of the petrophysical data of Uganda demonstrated their wide variation, thus emphasizing their importance in analyzing the bedrock variations in three dimensions. Using the density-susceptibility diagram, the data can be classified into six main groups: 1. A low density and susceptibility group, consisting of sedimentary and altered rocks. 2. Low-susceptibility, felsic rocks (e.g. quartzites and metasandstones). 3. Paramagnetic, felsic rocks (e.g. granites). 4. Ferrimagnetic, magnetite-containing felsic rocks (e.g. granites). 5. Paramagnetic mafic rocks (e.g. amphibolites and dolerites). 6. Ferrimagnetic, mafic rocks containing magnetite and high-density mafic minerals (mainly dolerites). Moreover, analysis revealed that the parameter distributions of even a single rock type (e.g. granites) can be very variable, forming separate clusters. This demonstrates that the simple calculation of density or susceptibility averages of rock types can be highly erratic. For example, the average can lie between two groups, where only few, if any, samples exist. Therefore, estimation of the representative density and susceptibility must be visually verified from these diagrams. The areal distribution of parameters and their calculated derivatives generally correlate well with the regional distribution of lithological and

  5. Relating pore-scale geometric controls on NMR and SIP parameters for improved petrophysical models of synthetic sand-clay mixtures

    NASA Astrophysics Data System (ADS)

    Osterman, G. K.; Keating, K.; Slater, L. D.; Binley, A. M.

    2013-12-01

    The microgeometry of porous geologic materials controls a wide range of key hydraulic parameters, such as permeability. Non-invasive geophysical methods have shown promise in mapping these properties in-situ over laterally extensive areas. Two near-surface geophysical techniques, nuclear magnetic resonance (NMR) and spectral induced polarization (SIP), demonstrate distinct relationships with porosity, grain size, and surface area. Permeability is also thought to be related to these physical properties suggesting that NMR and SIP can be used to estimate permeability. However, SIP lacks a universally accepted model and NMR is insensitive to anisotropy and pore-connectivity. Additionally, geochemical factors alter NMR and SIP measurements in non-unique manners. In this study, we performed a series of laboratory experiments on well-controlled sand-clay mixtures in order to constrain the geometric controls on measureable NMR and SIP responses in porous media. We combined the geophysical data to formulate better petrophysical models of key hydraulic parameters than would be possible using each method separately. NMR and SIP measurements were performed on different brine saturated mixtures of Ottawa sand and kaolin. Independent measurements were made to estimate the specific surface area, porosity, grain size distribution, and permeability for each sand-clay mixture. Additionally, the brine conductivity was varied in order to test the sensitivity of the NMR and SIP measurements to pore-fluid chemistry as well as determine the true electrical formation factor of the samples. Empirical relationships were first established between each physical property and the measured geophysical parameters using regression analysis. The resulting relationships form the foundation for future mechanistic permeability models that incorporate joint NMR and SIP measurements.

  6. Parameter selection and testing the soil water model SOIL

    NASA Astrophysics Data System (ADS)

    McGechan, M. B.; Graham, R.; Vinten, A. J. A.; Douglas, J. T.; Hooda, P. S.

    1997-08-01

    The soil water and heat simulation model SOIL was tested for its suitability to study the processes of transport of water in soil. Required parameters, particularly soil hydraulic parameters, were determined by field and laboratory tests for some common soil types and for soils subjected to contrasting treatments of long-term grassland and tilled land under cereal crops. Outputs from simulations were shown to be in reasonable agreement with independently measured field drain outflows and soil water content histories.

  7. Depositional cyclicity and scaling petrophysical parameters for characterization of fluid flow in carbonate platform reservoirs: San Andres outcrop, Algerita escarpment, New Mexico

    SciTech Connect

    Lucia, F.J.; Kerans, C.; Senger, R.K. )

    1992-04-01

    San Andres outcrops along the Algerita escarpment in the Guadalupe Mountains of New Mexico are composed of five sequences: a lower to middle San Andres sequence and four upper San Andres sequences. Within a sequence the predictable stacking patterns of cycles in different systems tracts, and of facies and rock-fabric successions within cycles, provide the necessary geologic framework for petrophysical quantification of geologic models. Rock fabric is a fundamental scale controlling the petrophysical properties of porosity, permeability, and capillarity. Four basic rock fabrics are present in the upper San Andres at Lawyer Canyon: dolograinstone, dolograin-dominated packstone, finely crystalline mud-dominated dolostone, and separate-vug dolograinstone. These four rock fabrics have unique average permeability values and porosity-permeability transforms. Permeability distribution was determined in the grainstone facies of cycle 1 at scales ranging from 1 in. to 100 ft. Variogram analysis of spatial permeability distribution indicates short-range correlation with a relatively high nugget, suggesting that permeability heterogeneity is largely random within a rock-fabric facies. A detailed cross section showing the nine cycles and the vertical and lateral distribution of rock fabrics within the cycles was converted to a permeability flow model using geometric mean permeabilities. The resulting rock-fabric flow model is suitable for input into reservoir simulators for performance prediction studies.

  8. Analysing petrophysical parameters of reservoir rock from the Ketzin pilot site (Germany) during long-term CO2-exposure experiments under thermodynamic conditions relevant for the geological storage of CO2

    NASA Astrophysics Data System (ADS)

    Zemke, K.; Fischer, S.; Liebscher, A.; Ketzin Team

    2012-04-01

    In the present study, 7 reservoir core samples from observation well Ktzi 202 at the Ketzin pilot storage site (Germany) were experimentally exposed to pure CO2 and synthetic reservoir brine at simulated reservoir conditions of 5.5 MPa and 40°C. Reservoir rocks are immature arcosic to litharenitic sandstones of the Upper Triassic Stuttgart Formation. After 15, 21, 24, and 40 months, respectively, autoclaves were opened and rock samples were taken for petrophysical characterisation and mineralogical and microbial analyses. Brine samples were analysed with respect to organic and inorganic components. Porosity and pore radii distribution have been investigated before and after the experiments by NMR relaxation and mercury injection. NMR measurements on brine-saturated rock core plugs potentially yield valuable information on the porous structure of the rock core. The distribution of NMR-T2 values (CPMG) reflects pore sizes within the rock core. NMR pore size is a derivative of the ratio pore surface to pore volume. The pore size derived by mercury injection is an area-equivalent diameter of throats connecting the pore system. Both methods produce petrophysical parameters required for calculating storage capacity and hydraulic properties (e.g. injectivity). Measured porosity data of the experimentally treated samples together with data from additional, untreated core samples from the Ketzin wells were also compared with results from wireline porosity determinations in the wells. Based on the NMR measurements, the permeability was calculated with standard parameters for sandstones after Timur-Coates. Mercury injection data was used to calculate sandstone permeabilities after Swanson (1981) and to furthermore determine the threshold pressure. NMR and mercury injection data generally indicate increased porosities and a shift to larger pore sizes during the first months. This suggests mineral dissolution during the experiments in agreement with the observed chemical

  9. Multivariate distributions of soil hydraulic parameters

    NASA Astrophysics Data System (ADS)

    Qu, Wei; Pachepsky, Yakov; Huisman, Johan Alexander; Martinez, Gonzalo; Bogena, Heye; Vereecken, Harry

    2014-05-01

    Statistical distributions of soil hydraulic parameters have to be known when synthetic fields of soil hydraulic properties need to be generated in ensemble modeling of soil water dynamics and soil water content data assimilation. Pedotransfer functions that provide statistical distributions of water retention and hydraulic conductivity parameters for textural classes are most often used in the parameter field generation. Presence of strong correlations can substantially influence the parameter generation results. The objective of this work was to review and evaluate available data on correlations between van Genuchten-Mualem (VGM) model parameters. So far, two different approaches were developed to estimate these correlations. The first approach uses pedotransfer functions to generate VGM parameters for a large number of soil compositions within a textural class, and then computes parameter correlations for each of the textural classes. The second approach computes the VGM parameter correlations directly from parameter values obtained by fitting VGM model to measured water retention and hydraulic conductivity data for soil samples belonging to a textural class. Carsel and Parish (1988) used the Rawls et al. (1982) pedotransfer functions, and Meyer et al. (1997) used the Rosetta pedotransfer algorithms (Schaap, 2002) to develop correlations according to the first approach. We used the UNSODA database (Nemes et al. 2001), the US Southern Plains database (Timlin et al., 1999), and the Belgian database (Vereecken et al., 1989, 1990) to apply the second approach. A substantial number of considerable (>0.7) correlation coefficients were found. Large differences were encountered between parameter correlations obtained with different approaches and different databases for the same textural classes. The first of the two approaches resulted in generally higher values of correlation coefficients between VGM parameters. However, results of the first approach application depend

  10. Calculation of petrophysical properties for Mishrif carbonate reservoir

    NASA Astrophysics Data System (ADS)

    Kadhim, Fadhil Sarhan; Samsuri, Ariffin; Idris, Ahmad Kamal

    2014-10-01

    The accurate calculations of petrophysical properties in carbonate reservoirs are the most challenging aspects of well log analysis. Many equations have been developed over the years based on known physical principles or on empirically derived relationships, which are used to calculate carbonate rock petrophysical properties. Carbonate reservoirs in the Middle East are very heterogeneous in terms of rock types. Therefore the reservoir should be split into layers on the basis of the dominant rock type in order to define average values and trends of petrophysical parameters in the reservoir rock. The saturation exponent (n) and cementation exponent (m) are calculated from well log data using Pickett method. The study made across the Mishrif carbonate formation, which is the shallowest formation of the hydrocarbon bearing zone in the NS oil field in the Middle East. Results show that the average formation water resistivity (Rw= 0.0243), average mud filtrate resistivity (Rmf= 0.199), Irreducible Water Saturation (Swi=0. 18), and Archie's parameters (m=1. 78, n= 2, and a=1). While porosity, true resistivity, and water saturation values with depth of formation were calculated by using Interactive Petrophysics software (IP V3.5, 2008). The computer process interpretation (CPI) illustrates that the shale member splits the Mishrif formation into two parts; Upper and Lower Mishrif. This study is a step to investigate petrophysical properties, which used to calculate water saturation that should use to estimate original oil in place and detected the perforation zones.

  11. Petrophysical evaluation of subterranean formations

    DOEpatents

    Klein, James D; Schoderbek, David A; Mailloux, Jason M

    2013-05-28

    Methods and systems are provided for evaluating petrophysical properties of subterranean formations and comprehensively evaluating hydrate presence through a combination of computer-implemented log modeling and analysis. Certain embodiments include the steps of running a number of logging tools in a wellbore to obtain a variety of wellbore data and logs, and evaluating and modeling the log data to ascertain various petrophysical properties. Examples of suitable logging techniques that may be used in combination with the present invention include, but are not limited to, sonic logs, electrical resistivity logs, gamma ray logs, neutron porosity logs, density logs, NRM logs, or any combination or subset thereof.

  12. Relationship between the erosion properties of soils and other parameters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil parameters are essential for erosion process prediction and ultimately improved model development, especially as they relate to dam and levee failure. Soil parameters including soil texture and structure, soil classification, soil compaction, moisture content, and degree of saturation can play...

  13. Estimating Infiltration Parameters from Basic Soil Properties

    NASA Astrophysics Data System (ADS)

    van de Genachte, G.; Mallants, D.; Ramos, J.; Deckers, J. A.; Feyen, J.

    1996-05-01

    Infiltration data were collected on two rectangular grids with 25 sampling points each. Both experimental grids were located in tropical rain forest (Guyana), the first in an Arenosol area and the second in a Ferralsol field. Four different infiltration models were evaluated based on their performance in describing the infiltration data. The model parameters were estimated using non-linear optimization techniques. The infiltration behaviour in the Ferralsol was equally well described by the equations of Philip, Green-Ampt, Kostiakov and Horton. For the Arenosol, the equations of Philip, Green-Ampt and Horton were significantly better than the Kostiakov model. Basic soil properties such as textural composition (percentage sand, silt and clay), organic carbon content, dry bulk density, porosity, initial soil water content and root content were also determined for each sampling point of the two grids. The fitted infiltration parameters were then estimated based on other soil properties using multiple regression. Prior to the regression analysis, all predictor variables were transformed to normality. The regression analysis was performed using two information levels. The first information level contained only three texture fractions for the Ferralsol (sand, silt and clay) and four fractions for the Arenosol (coarse, medium and fine sand, and silt and clay). At the first information level the regression models explained up to 60% of the variability of some of the infiltration parameters for the Ferralsol field plot. At the second information level the complete textural analysis was used (nine fractions for the Ferralsol and six for the Arenosol). At the second information level a principal components analysis (PCA) was performed prior to the regression analysis to overcome the problem of multicollinearity among the predictor variables. Regression analysis was then carried out using the orthogonally transformed soil properties as the independent variables. Results for

  14. Hyperspectral Technique for Detecting Soil Parameters

    NASA Astrophysics Data System (ADS)

    Garfagnoli, F.; Ciampalini, A.; Moretti, S.; Chiarantini, L.

    2011-12-01

    In satellite and airborne remote sensing, hyperspectral technique has become a very powerful tool, due to the possibility of rapidly realizing chemical/mineralogical maps of the studied areas. Many studies are trying to customize the algorithms to identify several geo-physical soil properties. The specific objective of this study is to investigate those soil characteristics, such as clay mineral content, influencing degradation processes (soil erosion and shallow landslides), by means of correlation analysis, in order to examine the possibility of predicting the selected property using high-resolution reflectance spectra and images. The study area is located in the Mugello basin, about 30 km north of Firenze (Tuscany, Italy). Agriculturally suitable terrains are assigned mainly to annual crops, marginally to olive groves, vineyards and orchards. Soils mostly belong to Regosols and Cambisols orders. An ASD FieldSpec spectroradiometer was used to obtain reflectance spectra from about 80 dried, crushed and sieved samples under controlled laboratory conditions. Samples were collected simultaneously with the flight of SIM.GA hyperspectral camera from Selex Galileo, over an area of about 5 km2 and their positions were recorded with a differential GPS. The quantitative determination of clay minerals content was performed by means of XRD and Rietveld refinement. Different chemometric techniques were preliminarily tested to correlate mineralogical records with reflectance data. A one component partial least squares regression model yielded a preliminary R2 value of 0.65. A slightly better result was achieved by plotting the absorption peak depth at 2210 versus total clay content (band-depth analysis). The complete SIM.GA hyperspectral geocoded row dataset, with an approximate pixel resolution of 0.6 m (VNIR) and 1.2 m (SWIR), was firstly transformed into at sensor radiance values, by applying calibration coefficients and parameters from laboratory measurements to non

  15. Spatial variability of soil hydraulics and remotely sensed soil parameters

    NASA Technical Reports Server (NTRS)

    Lascano, R. J.; Van Bavel, C. H. M.

    1982-01-01

    The development of methods to correctly interpret remotely sensed information about soil moisture and soil temperature requires an understanding of water and energy flow in soil, because the signals originate from the surface, or from a shallow surface layer, but reflect processes in the entire profile. One formidable difficulty in this application of soil physics is the spatial heterogeneity of natural soils. Earlier work has suggested that the heterogeneity of soil hydraulic properties may be described by the frequency distribution of a single scale factor. The sensitivity of hydraulic and energetic processes to the variation of this scale factor is explored with a suitable numerical model. It is believed that such an analysis can help in deciding how accurately and extensively basic physical properties of field soils need to be known in order to interpret thermal or radar waveband signals. It appears that the saturated hydraulic conductivity needs to be known only to its order of magnitude, and that the required accuracy of the soil water retention function is about 0.02 volume fraction. Furthermore, the results may be helpful in deciding how the total scene or view field, as perceived through a sensor, is composed from the actual mosaic of transient soil properties, such as surface temperature or surface soil moisture. However, the latter proposition presupposes a random distribution of permanent properties, a condition that may not be met in many instances, and no solution of the problem is apparent.

  16. Dynamics of soil parameters relevant for humanitarian demining

    NASA Astrophysics Data System (ADS)

    Obhođaš, Jasmina; Vdović, Neda; Valković, Vlado

    2005-12-01

    In this paper we analyzed characteristics of 6 different soils from the test field at the Ruđer Bošković Institute. Many soil properties relevant for the performance of humanitarian demining tools strongly depend on water content. This is an effort to understand better the soil moisture variability and to find soil parameters that can predict the water content regarding the weather conditions. Such knowledge will allow to optimize demining operations. To gather the main parameters like field capacity, rate and delay of water infiltration and soil water retention which are all related to soil texture, daily time-series of soil moisture from August to November 2001, where analyzed.

  17. Rock Mechanical Properties from Logs Petrophysics : Concepts and Results

    NASA Astrophysics Data System (ADS)

    Gaillot, Philippe; Crawford, Brian; Alramahi, Bashar; Karner, Steve

    2010-05-01

    The objective of the "geomechanics from logs" (GML) research project is to develop model-driven predictive software for determining rock mechanical properties (specifically rock strength, compressibility and fracability) from other, more easily measured, rock properties (e.g. lithology, porosity, clay volume, velocity) routinely derived from nuclear, resistivity and acoustic logging tools. To this end, geomechanics from logs seeks to increase fundamental understanding of the primary geologic controls on rock mechanical properties and to translate this new insight into novel predictive tools. In detail, GML predictors rely on (i) the generation of relational rock mechanical properties databases incorporating QC'd core-based laboratory measurements (both in-house and high-precision published data); (ii) the use of established rock physics models (e.g. friable sand, contact cement models) to investigate theoretical relationships between geologic processes, reservoir environment, rock microstructure and elastic, bulk and transport petrophysical attributes/properties; (iii) the subdivision of database rocks into generic lithotypes (e.g. sand, shaly sand, sandy shale, shale) with common petrophysical attributes/properties; (iv) the use of multivariate statistics to generate lithotype-dependent empirical predictive relationships between mechanical properties and log-derived petrophysical attributes/properties; (v) the estimation of uncertainties associated with predictive function parameters; (vi) the application and validation of mechanical properties predictive tools to well-documented case studies (e.g. sand strength for perforation stability, rock compressibility for reservoir simulation) to test overall performance and quantify uncertainty in predictions. This paper presents the results of various rock strength, rock compressibility and rock fracability case studies conducted in wells of different stratigraphic age and depositional environment. Overall, GML (i

  18. Estimating the distribution of radionuclides in agricultural soils - dependence on soil parameters.

    PubMed

    Hormann, Volker; Fischer, Helmut W

    2013-10-01

    In this study it is shown how radionuclide distributions in agricultural soils and their dependence on soil parameters can be quantitatively estimated. The most important sorption and speciation processes have been implemented into a numerical model using the geochemical code PHREEQC that is able to include specific soil and soil solution compositions. Using this model, distribution coefficients (Kd values) for the elements Cs, Ni, U and Se have been calculated for two different soil types. Furthermore, the dependencies of these Kd values on various soil parameters (e.g. pH value or organic matter content) have been evaluated. It is shown that for each element, an individual set of soil parameters is relevant for its solid-liquid distribution. The model may be used for the calculation of input parameters used by reference biosphere models (e.g. used for the risk assessment of nuclear waste repositories). PMID:23871968

  19. Estimating the distribution of radionuclides in agricultural soils - dependence on soil parameters.

    PubMed

    Hormann, Volker; Fischer, Helmut W

    2013-10-01

    In this study it is shown how radionuclide distributions in agricultural soils and their dependence on soil parameters can be quantitatively estimated. The most important sorption and speciation processes have been implemented into a numerical model using the geochemical code PHREEQC that is able to include specific soil and soil solution compositions. Using this model, distribution coefficients (Kd values) for the elements Cs, Ni, U and Se have been calculated for two different soil types. Furthermore, the dependencies of these Kd values on various soil parameters (e.g. pH value or organic matter content) have been evaluated. It is shown that for each element, an individual set of soil parameters is relevant for its solid-liquid distribution. The model may be used for the calculation of input parameters used by reference biosphere models (e.g. used for the risk assessment of nuclear waste repositories).

  20. Identification of optimal soil hydraulic functions and parameters for predicting soil moisture

    EPA Science Inventory

    We examined the accuracy of several commonly used soil hydraulic functions and associated parameters for predicting observed soil moisture data. We used six combined methods formed by three commonly used soil hydraulic functions – i.e., Brooks and Corey (1964) (BC), Campbell (19...

  1. Impact of Petrophysical Experiments on Quantitative Interpretation of 4D Seismic Data at Ketzin, Germany

    NASA Astrophysics Data System (ADS)

    Ivanova, A.; Lueth, S.

    2015-12-01

    Petrophysical investigations for CCS concern relationships between physical properties of rocks and geophysical observations for understanding behavior of injected CO2 in a geological formation. In turn 4D seismic surveying is a proven tool for CO2 monitoring. At the Ketzin pilot site (Germany) 4D seismic data have been acquired by means of a baseline (pre-injection) survey in 2005 and monitor surveys in 2009 and 2012. At Ketzin CO2 was injected in supercritical state from 2008 to 2013 in a sandstone saline aquifer (Stuttgart Formation) at a depth of about 650 m. The 4D seismic data from Ketzin reflected a pronounced effect of this injection. Seismic forward modeling using results of petrophysical experiments on two core samples fromthe target reservoir confirmed that effects of the injected CO2 on the 4D seismic data are significant. The petrophysical data were used in that modeling in order to reflect changes due to the CO2 injection in acoustic parameters of the reservoir. These petrophysical data were further used for a successful quantitative interpretation of the 4D seismic data at Ketzin. Now logs from a well (drilled in 2012) penetrating the reservoir containing information about changes in the acoustic parameters of the reservoir due to the CO2 injection are available. These logs were used to estimate impact of the petrophysical data on the qualitative and quantitative interpretation of the 4D seismic data at Ketzin. New synthetic seismograms were computed using the same software and the same wavelet as the old ones apart from the only difference and namely the changes in the input acoustic parameters would not be affected with any petrophysical experiments anymore. Now these changes were put in computing directly from the logs. In turn the new modelled changes due to the injection in the newly computed seismograms do not include any effects of the petrophysical data anymore. Key steps of the quantitative and qualitative interpretation of the 4D seismic

  2. Uncertainty in dual permeability model parameters for structured soils.

    PubMed

    Arora, B; Mohanty, B P; McGuire, J T

    2012-01-01

    Successful application of dual permeability models (DPM) to predict contaminant transport is contingent upon measured or inversely estimated soil hydraulic and solute transport parameters. The difficulty in unique identification of parameters for the additional macropore- and matrix-macropore interface regions, and knowledge about requisite experimental data for DPM has not been resolved to date. Therefore, this study quantifies uncertainty in dual permeability model parameters of experimental soil columns with different macropore distributions (single macropore, and low- and high-density multiple macropores). Uncertainty evaluation is conducted using adaptive Markov chain Monte Carlo (AMCMC) and conventional Metropolis-Hastings (MH) algorithms while assuming 10 out of 17 parameters to be uncertain or random. Results indicate that AMCMC resolves parameter correlations and exhibits fast convergence for all DPM parameters while MH displays large posterior correlations for various parameters. This study demonstrates that the choice of parameter sampling algorithms is paramount in obtaining unique DPM parameters when information on covariance structure is lacking, or else additional information on parameter correlations must be supplied to resolve the problem of equifinality of DPM parameters. This study also highlights the placement and significance of matrix-macropore interface in flow experiments of soil columns with different macropore densities. Histograms for certain soil hydraulic parameters display tri-modal characteristics implying that macropores are drained first followed by the interface region and then by pores of the matrix domain in drainage experiments. Results indicate that hydraulic properties and behavior of the matrix-macropore interface is not only a function of saturated hydraulic conductivity of the macroporematrix interface (Ksa ) and macropore tortuosity (lf ) but also of other parameters of the matrix and macropore domains.

  3. Estimating soil hydraulic parameters from transient flow experiments in a centrifuge using parameter optimization technique

    USGS Publications Warehouse

    Simunek, J.; Nimmo, J.R.

    2005-01-01

    A modified version of the Hydrus software package that can directly or inversely simulate water flow in a transient centrifugal field is presented. The inverse solver for parameter estimation of the soil hydraulic parameters is then applied to multirotation transient flow experiments in a centrifuge. Using time-variable water contents measured at a sequence of several rotation speeds, soil hydraulic properties were successfully estimated by numerical inversion of transient experiments. The inverse method was then evaluated by comparing estimated soil hydraulic properties with those determined independently using an equilibrium analysis. The optimized soil hydraulic properties compared well with those determined using equilibrium analysis and steady state experiment. Multirotation experiments in a centrifuge not only offer significant time savings by accelerating time but also provide significantly more information for the parameter estimation procedure compared to multistep outflow experiments in a gravitational field. Copyright 2005 by the American Geophysical Union.

  4. Determination and measurement of soil parameters for characterizing radon hazard of soils

    SciTech Connect

    Blue, T.E.; Jarzemba, M.S.

    1992-12-31

    There is little correlation between radon concentrations in soil and radon concentrations in homes. One explanation is that the soil radon concentration does not fully characterize the soil as a radon hazard. A mathematical model for the determination of important soil parameters for characterizing the flow of radon into a basement has been analyzed. We have identified important soil properties by mathematically modeling ventilated air enclosed in basement walls of thickness T (through which radon convects) and surrounded by soil of infinite extent (through which radon diffuses). The radon instantaneously mixed uniformly with the basement air and is lost from the basement air by ventilation ({lambda}{sub v}) and decay ({lambda}). It was found that not only the soil pore gas radon concentration, C{sub s}, but also the radon gas diffusion length, L{sub 3}, and the soil porosity, {epsilon}{sub 3}, are important to characterize the soil as a radon hazard. A model for determining the parameters C{sub s}, L{sub 3}, and {epsilon}{sub 3} has also been analyzed. It was found that it is possible to measure in situ these important soil parameters by monitoring the radon gas concentration time history of two cavities of different radii formed in the same soil.

  5. Sensitivity and uncertainty analysis of estimated soil hydraulic parameters for simulating soil water content

    NASA Astrophysics Data System (ADS)

    Gupta, Manika; Garg, Naveen Kumar; Srivastava, Prashant K.

    2014-05-01

    The sensitivity and uncertainty analysis has been carried out for the scalar parameters (soil hydraulic parameters (SHPs)), which govern the simulation of soil water content in the unsaturated soil zone. The study involves field experiments, which were conducted in real field conditions for wheat crop in Roorkee, India under irrigated conditions. Soil samples were taken for the soil profile of 60 cm depth at an interval of 15 cm in the experimental field to determine soil water retention curves (SWRCs). These experimentally determined SWRCs were used to estimate the SHPs by least square optimization under constrained conditions. Sensitivity of the SHPs estimated by various pedotransfer functions (PTFs), that relate various easily measurable soil properties like soil texture, bulk density and organic carbon content, is compared with lab derived parameters to simulate respective soil water retention curves. Sensitivity analysis was carried out using the monte carlo simulations and the one factor at a time approach. The different sets of SHPs, along with experimentally determined saturated permeability, are then used as input parameters in physically based, root water uptake model to ascertain the uncertainties in simulating soil water content. The generalised likelihood uncertainty estimation procedure (GLUE) was subsequently used to estimate the uncertainty bounds (UB) on the model predictions. It was found that the experimentally obtained SHPs were able to simulate the soil water contents with efficiencies of 70-80% at all the depths for the three irrigation treatments. The SHPs obtained from the PTFs, performed with varying uncertainties in simulating the soil water contents. Keywords: Sensitivity analysis, Uncertainty estimation, Pedotransfer functions, Soil hydraulic parameters, Hydrological modelling

  6. Integrating microbial diversity in soil carbon dynamic models parameters

    NASA Astrophysics Data System (ADS)

    Louis, Benjamin; Menasseri-Aubry, Safya; Leterme, Philippe; Maron, Pierre-Alain; Viaud, Valérie

    2015-04-01

    Faced with the numerous concerns about soil carbon dynamic, a large quantity of carbon dynamic models has been developed during the last century. These models are mainly in the form of deterministic compartment models with carbon fluxes between compartments represented by ordinary differential equations. Nowadays, lots of them consider the microbial biomass as a compartment of the soil organic matter (carbon quantity). But the amount of microbial carbon is rarely used in the differential equations of the models as a limiting factor. Additionally, microbial diversity and community composition are mostly missing, although last advances in soil microbial analytical methods during the two past decades have shown that these characteristics play also a significant role in soil carbon dynamic. As soil microorganisms are essential drivers of soil carbon dynamic, the question about explicitly integrating their role have become a key issue in soil carbon dynamic models development. Some interesting attempts can be found and are dominated by the incorporation of several compartments of different groups of microbial biomass in terms of functional traits and/or biogeochemical compositions to integrate microbial diversity. However, these models are basically heuristic models in the sense that they are used to test hypotheses through simulations. They have rarely been confronted to real data and thus cannot be used to predict realistic situations. The objective of this work was to empirically integrate microbial diversity in a simple model of carbon dynamic through statistical modelling of the model parameters. This work is based on available experimental results coming from a French National Research Agency program called DIMIMOS. Briefly, 13C-labelled wheat residue has been incorporated into soils with different pedological characteristics and land use history. Then, the soils have been incubated during 104 days and labelled and non-labelled CO2 fluxes have been measured at ten

  7. Hysteresis and uncertainty in soil water-retention curve parameters

    USGS Publications Warehouse

    Likos, William J.; Lu, Ning; Godt, Jonathan W.

    2014-01-01

    Accurate estimates of soil hydraulic parameters representing wetting and drying paths are required for predicting hydraulic and mechanical responses in a large number of applications. A comprehensive suite of laboratory experiments was conducted to measure hysteretic soil-water characteristic curves (SWCCs) representing a wide range of soil types. Results were used to quantitatively assess differences and uncertainty in three simplifications frequently adopted to estimate wetting-path SWCC parameters from more easily measured drying curves. They are the following: (1) αw=2αd, (2) nw=nd, and (3) θws=θds, where α, n, and θs are fitting parameters entering van Genuchten’s commonly adopted SWCC model, and the superscripts w and d indicate wetting and drying paths, respectively. The average ratio αw/αd for the data set was 2.24±1.25. Nominally cohesive soils had a lower αw/αd ratio (1.73±0.94) than nominally cohesionless soils (3.14±1.27). The average nw/nd ratio was 1.01±0.11 with no significant dependency on soil type, thus confirming the nw=nd simplification for a wider range of soil types than previously available. Water content at zero suction during wetting (θws) was consistently less than during drying (θds) owing to air entrapment. The θws/θds ratio averaged 0.85±0.10 and was comparable for nominally cohesive (0.87±0.11) and cohesionless (0.81±0.08) soils. Regression statistics are provided to quantitatively account for uncertainty in estimating hysteretic retention curves. Practical consequences are demonstrated for two case studies.

  8. Nonlinear genetic-based simulation of soil shear strength parameters

    NASA Astrophysics Data System (ADS)

    Mousavi, Seyyed Mohammad; Alavi, Amir Hossein; Gandomi, Amir Hossein; Mollahasani, Ali

    2011-12-01

    New nonlinear solutions were developed to estimate the soil shear strength parameters utilizing linear genetic programming (LGP). The soil cohesion intercept ( c) and angle of shearing resistance ( ϕ) were formulated in terms of the basic soil physical properties. The best models were selected after developing and controlling several models with different combinations of influencing parameters. Comprehensive experimental database used for developing the models was established upon a series of unconsolidated, undrained, and unsaturated triaxial tests conducted in this study. Further, sensitivity and parametric analyses were carried out. c and ϕ were found to be mostly influenced by the soil unit weight and liquid limit. In order to benchmark the proposed models, a multiple least squares regression (MLSR) analysis was performed. The validity of the models was proved on portions of laboratory results that were not included in the modelling process. The developed models are able to effectively learn the complex relationship between the soil strength parameters and their contributing factors. The LGP models provide a significantly better prediction performance than the regression models.

  9. Spatial variability of soil parameters - subsoils as heterogenic environments

    NASA Astrophysics Data System (ADS)

    Heinze, Stefanie; John, Stephan; Kirfel, Kristina; Mikutta, Robert; Niebuhr, Jana; Preusser, Sebastian; Marschner, Bernd

    2014-05-01

    Subsoils are known to store a high amount of organic carbon (40-60% of the total C-pool). 14C-dating detected that in subsoils organic matter (OM) age increased with increasing depth and reaches several 1000 years. The high age of subsoil OM might be caused by a complex structure, by limited access of OM for microbial decomposition or a limited input of fresh organic material. The latter, mostly reaches the subsoil through special pathways, like root channels, bioturbation processes or preferential flow pathways where dissolved organic carbon will be transported. The spatially concentrated input of OM supposed that the heterogeneity of physical, chemical, and biological soil parameters is higher in subsoils than in top soils. Within the DFG-FOR 1806 we investigated the heterogeneity of soil parameters in soil profiles (top and subsoil) of a podzolic Cambisol in a 95 years old beech forest in Lower Saxony, Germany. Three transects were established with a vertical and horizontal dimension of 2.00m and 3.15m, respectively. 64 soil samples were taken out of a grid in 10, 35, 60, 85, 110, 135, 160 and 185m depth with increasing horizontal distance to a main tree. To analyze the variability and relationship of soil properties in the soil profiles, analysis of soil physical (e.g. texture), chemical (e.g. organic C, dissolved organic C, total N, pH), and biological (e.g. enzyme activities, microbial biomass C) parameters were conducted within the research group. The results showed a very strong decline of organic C from 1.15% (10cm) to 0.12% (60cm). The differences of SOC were not pronounced with increasing distance to the main tree. Also total nitrogen decreased between 10 and 60cm strongly from 0.05 to 0.005%. The pH showed a slight increase between 10 and 35cm from 3.51 up to 4.27. For microbial biomass measures the same stratification was detected but the variance within biological parameters were higher in the subsoil than in the topsoil. Enzyme activities showed a

  10. Soil transport parameters of potassium under a tropical saline soil condition using STANMOD

    NASA Astrophysics Data System (ADS)

    Suzanye da Silva Santos, Rafaelly; Honorio de Miranda, Jarbas; Previatello da Silva, Livia

    2015-04-01

    Environmental responsibility and concerning about the final destination of solutes in soil, so more studies allow a better understanding about the solutes behaviour in soil. Potassium is a macronutrient that is required in high concentrations, been an extremely important nutrient for all agricultural crops. It plays essential roles in physiological processes vital for plant growth, from protein synthesis to maintenance of plant water balance, and is available to plants dissolved in soil water while exchangeable K is loosely held on the exchange sites on the surface of clay particles. K will tend to be adsorbed onto the surface of negatively charged soil particles. Potassium uptake is vital for plant growth but in saline soils sodium competes with potassium for uptake across the plasma membrane of plant cells. This can result in high Na+:K+ ratios that reduce plant growth and eventually become toxic. This study aimed to obtain soil transport parameters of potassium in saline soil, such as: pore water velocity in soil (v), retardation factor (R), dispersivity (λ) and dispersion coefficient (D), in a disturbed sandy soil with different concentrations of potassium chlorate solution (KCl), which is one of the most common form of potassium fertilizer. The experiment was carried out using soil samples collected in a depth of 0 to 20 cm, applying potassium chlorate solution containing 28.6, 100, 200 and 500 mg L-1 of K. To obtain transport parameters, the data were adjusted with the software STANMOD. At low concentrations, interaction between potassium and soil occur more efficiently. It was observed that only the breakthrough curve prepared with solution of 500 mg L-1 reached the applied concentration, and the solution of 28.6 mg L-1 overestimated the parameters values. The STANMOD proved to be efficient in obtaining potassium transport parameters; KCl solution to be applied should be greater than 500 mg L-1; solutions with low concentrations tend to overestimate

  11. Soil air CO2 concentration as an integrative parameter of soil structure

    NASA Astrophysics Data System (ADS)

    Ebeling, Corinna; Gaertig, Thorsten; Fründ, Heinz-Christian

    2015-04-01

    The assessment of soil structure is an important but difficult issue and normally takes place in the laboratory. Typical parameters are soil bulk density, porosity, water or air conductivity or gas diffusivity. All methods are time-consuming. The integrative parameter soil air CO2 concentration ([CO2]) can be used to assess soil structure in situ and in a short time. Several studies highlighted that independent of soil respiration, [CO2] in the soil air increases with decreasing soil aeration. Therefore, [CO2] is a useful indicator of soil aeration. Embedded in the German research project RÜWOLA, which focus on soil protection at forest sites, we investigated soil compaction and recovery of soil structure after harvesting. Therefore, we measured soil air CO2 concentrations continuously and in single measurements and compared the results with the measurements of bulk density, porosity and gas diffusivity. Two test areas were investigated: At test area 1 with high natural regeneration potential (clay content approx. 25 % and soil-pH between 5 and 7), solid-state CO2-sensors using NDIR technology were installed in the wheel track of different aged skidding tracks in 5 and 10 cm soil depths. At area 2 (acidic silty loam, soil-pH between 3.5 and 4), CO2-sensors and water-tension sensors (WatermarkR) were installed in 6 cm soil depth. The results show a low variance of [CO2] in the undisturbed soil with a long term mean from May to June 2014 between 0.2 and 0.5 % [CO2] in both areas. In the wheel tracks [CO2] was consistently higher. The long term mean [CO2] in the 8-year-old-wheel track in test area 1 is 5 times higher than in the reference soil and shows a high variation (mean=2.0 %). The 18-year-old wheel track shows a long-term mean of 1.2 % [CO2]. Furthermore, there were strong fluctuations of [CO2] in the wheel tracks corresponding to precipitation and humidity. Similar results were yielded with single measurements during the vegetation period using a portable

  12. Geotechnical Parameters of Alluvial Soils from in-situ Tests

    NASA Astrophysics Data System (ADS)

    Młynarek, Zbigniew; Stefaniak, Katarzyna; Wierzbicki, Jędrzej

    2012-10-01

    The article concentrates on the identification of geotechnical parameters of alluvial soil represented by silts found near Poznan and Elblag. Strength and deformation parameters of the subsoil tested were identified by the CPTU (static penetration) and SDMT (dilatometric) methods, as well as by the vane test (VT). Geotechnical parameters of the subsoil were analysed with a view to using the soil as an earth construction material and as a foundation for buildings constructed on the grounds tested. The article includes an analysis of the overconsolidation process of the soil tested and a formula for the identification of the overconsolidation ratio OCR. Equation 9 reflects the relation between the undrained shear strength and plasticity of the silts analyzed and the OCR value. The analysis resulted in the determination of the Nkt coefficient, which might be used to identify the undrained shear strength of both sediments tested. On the basis of a detailed analysis of changes in terms of the constrained oedometric modulus M0, the relations between the said modulus, the liquidity index and the OCR value were identified. Mayne's formula (1995) was used to determine the M0 modulus from the CPTU test. The usefullness of the sediments found near Poznan as an earth construction material was analysed after their structure had been destroyed and compacted with a Proctor apparatus. In cases of samples characterised by different water content and soil particle density, the analysis of changes in terms of cohesion and the internal friction angle proved that these parameters are influenced by the soil phase composition (Fig. 18 and 19). On the basis of the tests, it was concluded that the most desirable shear strength parameters are achieved when the silt is compacted below the optimum water content.

  13. Geotechnical Parameters of Alluvial Soils from in-situ Tests

    NASA Astrophysics Data System (ADS)

    Młynarek, Zbigniew; Stefaniak, Katarzyna; Wierzbicki, Jedrzej

    2012-10-01

    The article concentrates on the identification of geotechnical parameters of alluvial soil represented by silts found near Poznan and Elblag. Strength and deformation parameters of the subsoil tested were identified by the CPTU (static penetration) and SDMT (dilatometric) methods, as well as by the vane test (VT). Geotechnical parameters of the subsoil were analysed with a view to using the soil as an earth construction material and as a foundation for buildings constructed on the grounds tested. The article includes an analysis of the overconsolidation process of the soil tested and a formula for the identification of the overconsolidation ratio OCR. Equation 9 reflects the relation between the undrained shear strength and plasticity of the silts analyzed and the OCR value. The analysis resulted in the determination of the Nkt coefficient, which might be used to identify the undrained shear strength of both sediments tested. On the basis of a detailed analysis of changes in terms of the constrained oedometric modulus M0, the relations between the said modulus, the liquidity index and the OCR value were identified. Mayne's formula (1995) was used to determine the M0 modulus from the CPTU test. The usefullness of the sediments found near Poznan as an earth construction material was analysed after their structure had been destroyed and compacted with a Proctor apparatus. In cases of samples characterised by different water content and soil particle density, the analysis of changes in terms of cohesion and the internal friction angle proved that these parameters are influenced by the soil phase composition (Fig. 18 and 19). On the basis of the tests, it was concluded that the most desirable shear strength parameters are achieved when the silt is compacted below the optimum water content.

  14. Initial Measurements of Petrophysical Properties on Rocks from the Los Azufres, Mexico, Geothermal Field

    SciTech Connect

    Contreras, E.; Iglesias, E.; Razo, E.

    1986-01-21

    Petrophysical properties of geothermal reservoir rocks are valuable information for many activities, including reservoir characterization, modeling, field test analysis and planning of exploitation techniques. Petrophysical data of rocks from geothermal reservoirs located in volcanic areas is in general very scarce. In particular, no petrophysical data of rocks from the Los Azufres geothermal field area has ever been published. This work presents the results of initial petrophysical studies on outcrop rocks and drill core samples from the Los Azufres geothermal field. These studies are the first part of an ongoing experimental program intended to establish a data-base about physical properties of the Los Azufres rocks, in support of the many reservoir engineering activities which require of such information. The experimental work carried out consisted of laboratory measurements of density, porosity, permeability, compressibility, thermal conductivity, thermal expansion, electrical resistivity and sonic wave velocities. Some of the experiments were aimed at investigation of the effects of temperature, pressure, saturation and other parameters on the physical properties of rocks.

  15. Predicting Arsenate Adsorption by Soils Using Soil Chemical Parameters in the Constant Capacitance Model

    NASA Astrophysics Data System (ADS)

    Goldberg, S. R.; Lesch, S. M.; Suarez, D. L.

    2004-12-01

    Prediction of arsenate, As(V), adsorption and transport in soils requires detailed studies of As(V) adsorption and subsequent determination of model parameters. Arsenate adsorption on 49 soil samples belonging to six different soil orders was investigated as a function of solution pH (3-10). The set of soils consisted of two subgroups: one from the Midwestern U.S. and one primarily from the southwestern U.S. For most soils, As(V) adsorption increased with increasing solution pH, reached a maximum around pH 6-7, and decreased with further increases in solution pH. The constant capacitance model, a chemical surface complexation model, was well able to describe As(V) adsorption on the soil samples as a function of solution pH by simultaneously optimizing three As(V) surface complexation constants. The ability to describe As(V) adsorption as a function of pH represents an advancement over the Langmuir and Freundlich adsorption isotherm approaches. A general regression model was developed for predicting soil As(V) surface complexation constants from easily measured soil chemical characteristics using the As(V) adsorption data for 44 of the soils. These chemical properties were: cation exchange capacity (CEC), surface area (SA), inorganic carbon content (IOC), organic carbon content (OC), and iron oxide content (Fe). A preliminary analysis determined that the mean surface complexation constant values for the two soil subgroups were statistically different. For this reason, while the regression model equations for each soil subgroup contained common intercepts and ln(CEC) terms, the ln(IOC), ln(OC), ln(Fe), and ln(SA) terms were different. The constant capacitance model was able to predict As(V) adsorption on most of the 44 soils using the As(V) surface complexation constants predicted from the regression equations. The prediction equations were used to obtain values for As(V) surface complexation constants for the remaining five soils that had not been used to obtain the

  16. Spatial Prediction of Soil Classes by Using Soil Weathering Parameters Derived from vis-NIR Spectroscopy

    NASA Astrophysics Data System (ADS)

    Ramirez-Lopez, Leonardo; Alexandre Dematte, Jose

    2010-05-01

    There is consensus in the scientific community about the great need of spatial soil information. Conventional mapping methods are time consuming and involve high costs. Digital soil mapping has emerged as an area in which the soil mapping is optimized by the application of mathematical and statistical approaches, as well as the application of expert knowledge in pedology. In this sense, the objective of the study was to develop a methodology for the spatial prediction of soil classes by using soil spectroscopy methodologies related with fieldwork, spectral data from satellite image and terrain attributes in simultaneous. The studied area is located in São Paulo State, and comprised an area of 473 ha, which was covered by a regular grid (100 x 100 m). In each grid node was collected soil samples at two depths (layers A and B). There were extracted 206 samples from transect sections and submitted to soil analysis (clay, Al2O3, Fe2O3, SiO2 TiO2, and weathering index). The first analog soil class map (ASC-N) contains only soil information regarding from orders to subgroups of the USDA Soil Taxonomy System. The second (ASC-H) map contains some additional information related to some soil attributes like color, ferric levels and base sum. For the elaboration of the digital soil maps the data was divided into three groups: i) Predicted soil attributes of the layer B (related to the soil weathering) which were obtained by using a local soil spectral library; ii) Spectral bands data extracted from a Landsat image; and iii) Terrain parameters. This information was summarized by a principal component analysis (PCA) in each group. Digital soil maps were generated by supervised classification using a maximum likelihood method. The trainee information for this classification was extracted from five toposequences based on the analog soil class maps. The spectral models of weathering soil attributes shown a high predictive performance with low error (R2 0.71 to 0.90). The spatial

  17. Estimation of field-scale soil hydraulic and dielectric parametersthrough joint inversion of GPR and hydrological data

    SciTech Connect

    Kowalsky, Michael B.; Finsterle, Stefan; Peterson, John; Hubbard,Susan; Rubin, Yoram; Majer, Ernest; Ward, Andy; Gee, Glendon

    2005-05-05

    A method is described for jointly using time-lapse multiple-offset cross-borehole ground-penetrating radar (GPR) travel time measurements and hydrological measurements to estimate field-scale soil hydraulic parameters and parameters of the petrophysical function, which relates soil porosity and water saturation to the effective dielectric constant. We build upon previous work to take advantage of a wide range of GPR data acquisition configurations and to accommodate uncertainty in the petrophysical function. Within the context of water injection experiments in the vadose zone, we test our inversion methodology with synthetic examples and apply it to field data. The synthetic examples show that while realistic errors in the petrophysical function cause substantial errors in the soil hydraulic parameter estimates,simultaneously estimating petrophysical parameters allows for these errors to be minimized. Additionally, we observe in some cases that inaccuracy in the GPR simulator causes systematic error in simulated travel times, making necessary the simultaneous estimation of a correction parameter. We also apply the method to a three-dimensional field setting using time-lapse GPR and neutron probe (NP) data sets collected during an infiltration experiment at the U.S. Department of Energy (DOE) Hanford site in Washington. We find that inclusion of GPR data in the inversion procedure allows for improved predictions of water content, compared to predictions made using NP data alone.

  18. Rock-fabric/petrophysical classification of carbonate pore space for reservoir characterization

    SciTech Connect

    Lucia, F.J.

    1995-09-01

    This paper defines the important geologic parameters that can be described and mapped to allow accurate petrophysical quantification of carbonate geologic models. All pore space is divided into interparticle (intergrain and intercrystal) and vuggy pores. In nonvuggy carbonate rocks, permeability and capillary properties can be described in terms of particle size, sorting, and interparticle porosity (total porosity minus vuggy porosity). Particle size and sorting in limestones can be described using a modified Dunham approach, classifying packstone as grain dominated or mud dominated, depending on the presence or absence of intergrain pore space. To describe particle size and sorting in dolostones, dolomite crystal size must be added to the modified Dunham terminology. Larger dolomite crystal size improves petrophysical properties in mud-dominated fabrics, wheras variations in dolomite crystal size have little effect on the petrophysical properties of grain-dominated fabrics. A description of vuggy pore space that relates to petrophysical properties must be added to the description of interparticle pore space to complete the petrophysical characterization. Vuggy pore space is divided into separate vugs and touching vugs on the basis of vug interconnection. Separate vugs are fabric selective and are connected only through the interparticle pore network. Separate vug porosity contributes little to permeability and should be subtracted from total porosity to obtain interparticle porosity for permeability estimation. Separate-vug pore space is generally considered to by hydrocarbon filled in reservoirs; however, intragranular microporosity is composed of small pore sizes and may contain capillary-held connate water within the reservoir. Touching vugs are nonfabric selective and form an interconnected pore system independent of the interparticle system.

  19. Soil hydrodynamic parameter determination using Ground-Penetrating Radar monitoring

    NASA Astrophysics Data System (ADS)

    Leger, E.

    2015-12-01

    Soil hydraulic properties, represented by the soil water retention andhydraulic conductivity functions, dictate water flow in the vadosezone, from surface to aquifers. Understanding the water flow dynamichas important implications for estimating available water resourcesand flood forecasting. It is also crucial in evaluating the dynamicsof chemical pollutants in soil and in assessing the risks ofgroundwater pollution. Ground Penetrating Radar is a geophysicalmethod particularly suited to measure contrasts of electromagneticparameters such as those created by water content variations in soils.We developed coupled hydrodynamic and electromagnetic numericalmodeling to invert the two way travel times associated withreflections corresponding to strong dielectric permittivity contrastssuch as wetting front and wetting bulb.We will present three different techniques using Ground PenetratingRadar monitoring: one using a single ring infiltrometer, an other oneusing shallow boreholes and the last one being a laboratory largecylindrical tank in which we applied different water table levels.We used the parametrical Mualem-van Genuchten model to fit soil-waterretention and hydraulic conductivity functions. Using GroundPenetrating Radar data inversion, we optimized the Mualem-vanGenuchten parameters using Shuffled Complex Evolution algorithm.Results are compared with classical laboratory and field methods.

  20. Soil-related Input Parameters for the Biosphere Model

    SciTech Connect

    A. J. Smith

    2003-07-02

    This analysis is one of the technical reports containing documentation of the Environmental Radiation Model for Yucca Mountain Nevada (ERMYN), a biosphere model supporting the Total System Performance Assessment (TSPA) for the geologic repository at Yucca Mountain. The biosphere model is one of a series of process models supporting the Total System Performance Assessment (TSPA) for the Yucca Mountain repository. A graphical representation of the documentation hierarchy for the ERMYN biosphere model is presented in Figure 1-1. This figure shows the interrelationships among the products (i.e., analysis and model reports) developed for biosphere modeling, and the plan for development of the biosphere abstraction products for TSPA, as identified in the ''Technical Work Plan: for Biosphere Modeling and Expert Support'' (BSC 2003 [163602]). It should be noted that some documents identified in Figure 1-1 may be under development at the time this report is issued and therefore not available. This figure is included to provide an understanding of how this analysis report contributes to biosphere modeling in support of the license application, and is not intended to imply that access to the listed documents is required to understand the contents of this report. This report, ''Soil Related Input Parameters for the Biosphere Model'', is one of the five analysis reports that develop input parameters for use in the ERMYN model. This report is the source documentation for the six biosphere parameters identified in Table 1-1. ''The Biosphere Model Report'' (BSC 2003 [160699]) describes in detail the conceptual model as well as the mathematical model and its input parameters. The purpose of this analysis was to develop the biosphere model parameters needed to evaluate doses from pathways associated with the accumulation and depletion of radionuclides in the soil. These parameters support the calculation of radionuclide concentrations in soil from on-going irrigation and ash

  1. Long-term effects of deep soil loosening on root distribution and soil physical parameters in compacted lignite mine soils

    NASA Astrophysics Data System (ADS)

    Badorreck, Annika; Krümmelbein, Julia; Raab, Thomas

    2015-04-01

    Soil compaction is a major problem of soils on dumped mining substrates in Lusatia, Germany. Deep ripping and cultivation of deep rooting plant species are considered to be effective ways of agricultural recultivation. Six years after experiment start, we studied the effect of initial deep soil loosening (i.e. down to 65 cm) on root systems of rye (Secale cereale) and alfalfa (Medicago sativa) and on soil physical parameters. We conducted a soil monolith sampling for each treatment (deep loosened and unloosened) and for each plant species (in three replicates, respectively) to determine root diameter, length density and dry mass as well as soil bulk density. Further soil physical analysis comprised water retention, hydraulic conductivity and texture in three depths. The results showed different reactions of the root systems of rye and alfalfa six years after deep ripping. In the loosened soil the root biomass of the rye was lower in depths of 20-40 cm and the root biomass of alfalfa was also decreased in depths of 20-50 cm together with a lower root diameter for both plant species. Moreover, total and fine root length density was higher for alfalfa and vice versa for rye. The soil physical parameters such as bulk density showed fewer differences, despite a higher bulk density in 30-40cm for the deep loosened rye plot which indicates a more pronounced plough pan.

  2. Bioremediation treatment of hydrocarbon-contaminated Arctic soils: influencing parameters.

    PubMed

    Naseri, Masoud; Barabadi, Abbas; Barabady, Javad

    2014-10-01

    The Arctic environment is very vulnerable and sensitive to hydrocarbon pollutants. Soil bioremediation is attracting interest as a promising and cost-effective clean-up and soil decontamination technology in the Arctic regions. However, remoteness, lack of appropriate infrastructure, the harsh climatic conditions in the Arctic and some physical and chemical properties of Arctic soils may reduce the performance and limit the application of this technology. Therefore, understanding the weaknesses and bottlenecks in the treatment plans, identifying their associated hazards, and providing precautionary measures are essential to improve the overall efficiency and performance of a bioremediation strategy. The aim of this paper is to review the bioremediation techniques and strategies using microorganisms for treatment of hydrocarbon-contaminated Arctic soils. It takes account of Arctic operational conditions and discusses the factors influencing the performance of a bioremediation treatment plan. Preliminary hazard analysis is used as a technique to identify and assess the hazards that threaten the reliability and maintainability of a bioremediation treatment technology. Some key parameters with regard to the feasibility of the suggested preventive/corrective measures are described as well.

  3. Establishing principal soil quality parameters influencing earthworms in urban soils using bioassays.

    PubMed

    Hankard, Peter K; Bundy, Jacob G; Spurgeon, David J; Weeks, Jason M; Wright, Julian; Weinberg, Claire; Svendsen, Claus

    2005-01-01

    Potential contamination at ex-industrial sites means that, prior to change of use, it will be necessary to quantify the extent of risks to potential receptors. To assess ecological hazards, it is often suggested to use biological assessment to augment chemical analyses. Here we investigate the potential of a commonly recommended bioassay, the earthworm reproduction test, to assess the status of urban contaminated soils. Sample points at all study sites had contaminant concentrations above the Dutch soil criteria Target Values. In some cases, the relevant Intervention Values were exceeded. Earthworm survival at most points was high, but reproduction differed significantly in soil from separate patches on the same site. When the interrelationships between soil parameters and reproduction were studied, it was not possible to create a good model of site soil toxicity based on single or even multiple chemical measurements of the soils. We thus conclude that chemical analysis alone is not sufficient to characterize soil quality and confirms the value of biological assays for risk assessment of potentially contaminated soils. PMID:15519451

  4. Petrophysical Properties (Density and Magnetization) of Rocks from the Suhbaatar-Ulaanbaatar-Dalandzadgad Geophysical Profile in Mongolia and Their Implications

    PubMed Central

    Gao, Jintian; Gu, Zuowen; Dagva, Baatarkhuu; Tserenpil, Batsaikhan

    2013-01-01

    Petrophysical properties of 585 rock samples from the Suhbaatar-Ulaanbaatar-Dalandzadgad geophysical profile in Mongolia are presented. Based on the rock classifications and tectonic units, petrophysical parameters (bulk density, magnetic susceptibility, intensity of natural remanent magnetization, and Köenigsberger ratio) of these rocks are summarized. Results indicate that (1) significant density contrast of different rocks would result in variable gravity anomalies along the profile; (2) magnetic susceptibility and natural remanent magnetization of all rocks are variable, covering 5-6 orders of magnitude, which would make a variable induced magnetization and further links to complex magnetic anomalies in ground surface; (3) the distribution of rocks with different lithologies controls the pattern of lithospheric magnetic anomaly along the profile. The petrophysical database thus provides not only one of the keys to understand the geological history and structure of the profile, but also essential information for analysis and interpretation of the geophysical (e.g., magnetic and gravity) survey data. PMID:24324382

  5. Soil-Related Input Parameters for the Biosphere Model

    SciTech Connect

    A. J. Smith

    2004-09-09

    This report presents one of the analyses that support the Environmental Radiation Model for Yucca Mountain Nevada (ERMYN). The ''Biosphere Model Report'' (BSC 2004 [DIRS 169460]) describes the details of the conceptual model as well as the mathematical model and the required input parameters. The biosphere model is one of a series of process models supporting the postclosure Total System Performance Assessment (TSPA) for the Yucca Mountain repository. A schematic representation of the documentation flow for the Biosphere input to TSPA is presented in Figure 1-1. This figure shows the evolutionary relationships among the products (i.e., analysis and model reports) developed for biosphere modeling, and the biosphere abstraction products for TSPA, as identified in the ''Technical Work Plan for Biosphere Modeling and Expert Support'' (TWP) (BSC 2004 [DIRS 169573]). This figure is included to provide an understanding of how this analysis report contributes to biosphere modeling in support of the license application, and is not intended to imply that access to the listed documents is required to understand the contents of this report. This report, ''Soil-Related Input Parameters for the Biosphere Model'', is one of the five analysis reports that develop input parameters for use in the ERMYN model. This report is the source documentation for the six biosphere parameters identified in Table 1-1. The purpose of this analysis was to develop the biosphere model parameters associated with the accumulation and depletion of radionuclides in the soil. These parameters support the calculation of radionuclide concentrations in soil from on-going irrigation or ash deposition and, as a direct consequence, radionuclide concentration in other environmental media that are affected by radionuclide concentrations in soil. The analysis was performed in accordance with the TWP (BSC 2004 [DIRS 169573]) where the governing procedure was defined as AP-SIII.9Q, ''Scientific Analyses''. This

  6. Improving the relationship between soil characteristics and metal bioavailability by using reactive fractions of soil parameters in calcareous soils.

    PubMed

    de Santiago-Martín, Ana; van Oort, Folkert; González, Concepción; Quintana, José R; Lafuente, Antonio L; Lamy, Isabelle

    2015-01-01

    The contribution of the nature instead of the total content of soil parameters relevant to metal bioavailability in lettuce was tested using a series of low-polluted Mediterranean agricultural calcareous soils offering natural gradients in the content and composition of carbonate, organic, and oxide fractions. Two datasets were compared by canonical ordination based on redundancy analysis: total concentrations (TC dataset) of main soil parameters (constituents, phases, or elements) involved in metal retention and bioavailability; and chemically defined reactive fractions of these parameters (RF dataset). The metal bioavailability patterns were satisfactorily explained only when the RF dataset was used, and the results showed that the proportion of crystalline Fe oxides, dissolved organic C, diethylene-triamine-pentaacetic acid (DTPA)-extractable Cu and Zn, and a labile organic pool accounted for 76% of the variance. In addition, 2 multipollution scenarios by metal spiking were tested that showed better relationships with the RF dataset than with the TC dataset (up to 17% more) and new reactive fractions involved. For Mediterranean calcareous soils, the use of reactive pools of soil parameters rather than their total contents improved the relationships between soil constituents and metal bioavailability. Such pool determinations should be systematically included in studies dealing with bioavailability or risk assessment.

  7. Within-field variability of plant and soil parameters

    NASA Technical Reports Server (NTRS)

    Ulaby, F. T. (Principal Investigator); Brisco, B.; Dobson, C.

    1981-01-01

    The variability of ground truth data collected for vegetation experiments was investigated. Two fields of wheat and one field of corn were sampled on two different dates. The variability of crop and soil parameters within a field, between two fields of the same type, and within a field over time were compared statistically. The number of samples from each test site required in order to be able to determine with confidence the mean and standard deviations for a given variable was determined. Eight samples were found to be adequate for plant height determinations, while twenty samples were required for plant moisture and soil moisture characterization. Eighteen samples were necessary for detecting within field variability over time and for between field variability for the same crop. The necessary sample sites vary according to the physiological growth stage of the crop and recent weather events that affect the moisture and/or height characteristics of the field in question.

  8. Relevant magnetic and soil parameters as potential indicators of soil conservation status of Mediterranean agroecosystems

    NASA Astrophysics Data System (ADS)

    Quijano, Laura; Chaparro, Marcos A. E.; Marié, Débora C.; Gaspar, Leticia; Navas, Ana

    2014-09-01

    The main sources of magnetic minerals in soils unaffected by anthropogenic pollution are iron oxides and hydroxides derived from parent materials through soil formation processes. Soil magnetic minerals can be used as indicators of environmental factors including soil forming processes, degree of pedogenesis, weathering processes and biological activities. In this study measurements of magnetic susceptibility are used to detect the presence and the concentration of soil magnetic minerals in topsoil and bulk samples in a small cultivated field, which forms a hydrological unit that can be considered to be representative of the rainfed agroecosystems of Mediterranean mountain environments. Additional magnetic studies such as isothermal remanent magnetization (IRM), anhysteretic remanent magnetization (ARM) and thermomagnetic measurements are used to identify and characterize the magnetic mineralogy of soil minerals. The objectives were to analyse the spatial variability of the magnetic parameters to assess whether topographic factors, soil redistribution processes, and soil properties such as soil texture, organic matter and carbonate contents analysed in this study, are related to the spatial distribution pattern of magnetic properties. The medians of mass specific magnetic susceptibility at low frequency (χlf) were 36.0 and 31.1 × 10-8 m3 kg-1 in bulk and topsoil samples respectively. High correlation coefficients were found between the χlf in topsoil and bulk core samples (r = 0.951, p < 0.01). In addition, volumetric magnetic susceptibility was measured in situ in the field (κis) and values varied from 13.3 to 64.0 × 10-5 SI. High correlation coefficients were found between χlf in topsoil measured in the laboratory and volumetric magnetic susceptibility field measurements (r = 0.894, p < 0.01). The results obtained from magnetic studies such as IRM, ARM and thermomagnetic measurements show the presence of magnetite, which is the predominant magnetic carrier

  9. Two-dimensional nuclear magnetic resonance petrophysics.

    PubMed

    Sun, Boqin; Dunn, Keh-Jim

    2005-02-01

    Two-dimensional nuclear magnetic resonance (2D NMR) opens a wide area for exploration in petrophysics and has significant impact to petroleum logging technology. When there are multiple fluids with different diffusion coefficients saturated in a porous medium, this information can be extracted and clearly delineated from CPMG measurements of such a system either using regular pulsing sequences or modified two window sequences. The 2D NMR plot with independent variables of T2 relaxation time and diffusion coefficient allows clear separation of oil and water signals in the rocks. This 2D concept can be extended to general studies of fluid-saturated porous media involving other combinations of two or more independent variables, such as chemical shift and T1/T2 relaxation time (reflecting pore size), proton population and diffusion contrast, etc. PMID:15833623

  10. Magnetic resonance imaging in laboratory petrophysical core analysis

    NASA Astrophysics Data System (ADS)

    Mitchell, J.; Chandrasekera, T. C.; Holland, D. J.; Gladden, L. F.; Fordham, E. J.

    2013-05-01

    wettability. The history of MRI in petrophysics is reviewed and future directions considered, including advanced data processing techniques such as compressed sensing reconstruction and Bayesian inference analysis of under-sampled data. Although this review focuses on rock core analysis, the techniques described are applicable in a wider context to porous media in general, such as cements, soils, ceramics, and catalytic materials.

  11. Towards an integrated petrophysical tool for multiphase flow properties of core samples

    SciTech Connect

    Lenormand, R.

    1997-08-01

    This paper describes the first use of an Integrated Petrophysical Tool (IPT) on reservoir rock samples. The IPT simultaneously measures the following petrophysical properties: (1) Complete capillary pressure cycle: primary drainage, spontaneous and forced imbibitions, secondary drainage (the cycle leads to the wettability of the core by using the USBM index); End-points and parts of the relative permeability curves; Formation factor and resistivity index. The IPT is based on the steady-state injection of one fluid through the sample placed in a Hassler cell. The experiment leading to the whole Pc cycle on two reservoir sandstones consists of about 30 steps at various oil or water flow rates. It takes about four weeks and is operated at room conditions. Relative permeabilities are in line with standard steady-state measurements. Capillary pressures are in accordance with standard centrifuge measurements. There is no comparison for the resistivity index, but the results are in agreement with literature data. However, the accurate determination of saturation remains the main difficulty and some improvements are proposed. In conclusion, the Integrated Petrophysical Tool is as accurate as standard methods and has the advantage of providing the various parameters on the same sample and during a single experiment. The FIT is easy to use and can be automated. In addition, it can be operated in reservoir conditions.

  12. Characterizing petrophysical properties of carbonate rocks using nuclear magnetic resonance and spectral induced polarization

    NASA Astrophysics Data System (ADS)

    Zhang, Fan; Zhang, Chi; Rankey, Eugene

    2016-04-01

    Unlike sandstones, with well-characterized correlations between porosity and permeability, carbonate rocks are well known for their highly complex petrophysical behaviors due to their intrinsically heterogeneous pore shape, pore size, and pore distributions and connectivity. The characterization of petrophysical properties of carbonate rocks, including rock properties and rock-fluid interactions, remains big challenges. This laboratory study focuses on integrating two geophysical methods: nuclear magnetic resonance (NMR) and spectral induced polarization (SIP) to determine porosity, pore size distribution, and permeability of carbonate rocks. NMR measures the relaxation of hydrogen nuclei at pore scale. Samples with different pore structures saturated by fluids have molecular relaxation responses to the external magnetic field which could generate various NMR signals. Permeability estimation from NMR in siliciclastic rocks is routine, however, is problematic in carbonates. SIP determines complex resistivity of a sample across a wide range of frequency and is sensitive to variations in the properties of solid-fluid and fluid-fluid interfaces in porous media. Previous studies investigated the relationships between permeability and parameters derived from SIP data, but are restricted to narrow lithology range. Our study used carbonate core samples from three depositional environments: tidal zone, shallow marine, and platform/reef margin of an atoll. Samples were fully saturated by water for T2 relaxation measurements and complex conductivity measurements at low frequencies. We compare the pore volume to surface area ratio measured from NMR and SIP and assess the applicability of established petrophysical models to estimate permeability from NMR and SIP data. We hope to build a relationship between NMR signals, SIP responses and petrophysical properties in carbonate rocks. The results could also provide new data and help further understand the unique and complex pore

  13. Petrophysical core characterization at supercritical geothermal conditions

    NASA Astrophysics Data System (ADS)

    Kummerow, Juliane; Raab, Siegfried

    2015-04-01

    There is a growing scientific interest in the exploitation of supercritical geothermal reservoirs to increase the efficiency of geothermal power plants. The utilisation of geothermal energy requires in any case the detailed knowledge of the reservoir. In reservoir engineering, the characterisation of the geothermal system by electrical resistivity tomography (ERT) is a common geophysical exploration and monitoring strategy. For a realistic interpretation of the field measurements it is necessary to know both, the physical properties of the rock and those of the interacting fluid at defined temperature and pressure conditions. While there have been made great effort in determine the physical and chemical properties of water above its critical point (Tcritical = 374.21° C and pcritical = 221.2 bar), the influence of fluid-rock interactions on petrophysical properties in supercritical aqueous systems is nearly unknown. At supercritical conditions the viscosity of the fluid is low, which enhances the mass transfer and diffusion-controlled chemical reactions. This may have considerable effects on the porosity and hydraulic properties of a rock. To investigate high-enthalpy fluid-rock systems, in the framework of the EU-funded project IMAGE we have built a new percolation set-up, which allows for the measurement of electrical resistivity and permeability of rock samples at controlled supercritical conditions of aqueous fluids (pore pressure = 400 bar and a temperature = 400° C). First results will be presented.

  14. Evaluating petrophysical relationships in fractured rock using geophysical measurements

    NASA Astrophysics Data System (ADS)

    Robinson, J.; Slater, L. D.; Keating, K.; Parker, B. L.; Rose, C.; Meyer, J. R.; Johnson, C. D.; Robinson, T.; Pehme, P.; Chapman, S.; Day-Lewis, F. D.

    2015-12-01

    Quantification of the pore geometric properties controlling mass transfer rates in fractured rock aquifers is a challenging characterization problem, especially given the scales of heterogeneity. The efficiency of in-situ remediation efforts that target hydraulically connected and dead-end fracture zones is limited, in part, due to the diffusion of aqueous phase contaminants into and out of the less-mobile pore spaces in the matrix surrounding fractures. Two geophysical technologies, complex resistivity (CR) and nuclear magnetic resonance (NMR) are sensitive to pore geometry and may provide key information on transport parameters where diffusion can be a limiting factor in and around boreholes. We present laboratory CR and NMR data from cores collected from field sites with variable lithologies and examine the sensitivity of these measurements to less-mobile versus mobile porosity. Supporting data include surface area measurements using the Brunauer-Emmett-Teller (BET) method, pore size distributions from mercury porosimetry, gravimetric measurements of matrix total porosity and gas permeability. We examine the predictive capability of CR and NMR to determine these pore scale properties as a function of geological setting. The petrophysical relationships illustrate the potential for use of new borehole logging tools to determine the spatial variability of physical properties controlling mass transfer close to fractures. The correlations of measurements to rock-type specific relations indicate that minimal core measurements might be needed to calibrate the results to a specific site.

  15. Modeling soil detachment capacity by rill flow using hydraulic parameters

    NASA Astrophysics Data System (ADS)

    Wang, Dongdong; Wang, Zhanli; Shen, Nan; Chen, Hao

    2016-04-01

    The relationship between soil detachment capacity (Dc) by rill flow and hydraulic parameters (e.g., flow velocity, shear stress, unit stream power, stream power, and unit energy) at low flow rates is investigated to establish an accurate experimental model. Experiments are conducted using a 4 × 0.1 m rill hydraulic flume with a constant artificial roughness on the flume bed. The flow rates range from 0.22 × 10-3 m2 s-1 to 0.67 × 10-3 m2 s-1, and the slope gradients vary from 15.8% to 38.4%. Regression analysis indicates that the Dc by rill flow can be predicted using the linear equations of flow velocity, stream power, unit stream power, and unit energy. Dc by rill flow that is fitted to shear stress can be predicted with a power function equation. Predictions based on flow velocity, unit energy, and stream power are powerful, but those based on shear stress, especially on unit stream power, are relatively poor. The prediction based on flow velocity provides the best estimates of Dc by rill flow because of the simplicity and availability of its measurements. Owing to error in measuring flow velocity at low flow rates, the predictive abilities of Dc by rill flow using all hydraulic parameters are relatively lower in this study compared with the results of previous research. The measuring accuracy of experiments for flow velocity should be improved in future research.

  16. Petrophysical characterization of the Marlin Discovery, Deepwater Gulf of Mexico

    SciTech Connect

    Clemenceau, G.R.; Lockett, C.F. )

    1996-01-01

    This presentation discusses the petrophysical characterization of the Marlin discovery, a high quality gas and oil reservoir in the Deepwater Northern Gulf of Mexico. Amoco drilled the Marlin discovery well in May 1993 on Viosca Knoll Block 915. Approximately 100 MMBOE is structurally trapped here within Miocene deep-sea tan sands at 11,000 feet subsea. The petrophysical characterization of Marlin is based upon conventional core tests and data from three wells. The Marlin reservoir rock types are characterized based upon differences between their petrophysical properties. The properties, which include porosity, permeability, pore throat radius, and grain size, are derived from routine and special core analysis of a 40 foot conventional core recovered from the discovery well. Relative permeability, and capillary pressure tests, conducted at reservoir stress, further describe the rock types. The petrophysical properties average as follows; porosity 28%, permeability 1200 mD, porethroat radius 24 microns, and mean grain size 180 microns. By integrating this petrophysical model with a geologic model, that utilizes conventional core, well log, and 3D seismic interpretation, a 3-dimensional flow unit model was created for input to a reservoir simulation.

  17. Joint inversion of geophysical data using petrophysical clustering and facies deformation wth the level set technique

    NASA Astrophysics Data System (ADS)

    Revil, A.

    2015-12-01

    Geological expertise and petrophysical relationships can be brought together to provide prior information while inverting multiple geophysical datasets. The merging of such information can result in more realistic solution in the distribution of the model parameters, reducing ipse facto the non-uniqueness of the inverse problem. We consider two level of heterogeneities: facies, described by facies boundaries and heteroegenities inside each facies determined by a correlogram. In this presentation, we pose the geophysical inverse problem in terms of Gaussian random fields with mean functions controlled by petrophysical relationships and covariance functions controlled by a prior geological cross-section, including the definition of spatial boundaries for the geological facies. The petrophysical relationship problem is formulated as a regression problem upon each facies. The inversion of the geophysical data is performed in a Bayesian framework. We demonstrate the usefulness of this strategy using a first synthetic case for which we perform a joint inversion of gravity and galvanometric resistivity data with the stations located at the ground surface. The joint inversion is used to recover the density and resistivity distributions of the subsurface. In a second step, we consider the possibility that the facies boundaries are deformable and their shapes are inverted as well. We use the level set approach to perform such deformation preserving prior topological properties of the facies throughout the inversion. With the help of prior facies petrophysical relationships and topological characteristic of each facies, we make posterior inference about multiple geophysical tomograms based on their corresponding geophysical data misfits. The method is applied to a second synthetic case showing that we can recover the heterogeneities inside the facies, the mean values for the petrophysical properties, and, to some extent, the facies boundaries using the 2D joint inversion of

  18. Hydraulic parameter estimation by remotely-sensed top soil moisture observations with the particle filter

    NASA Astrophysics Data System (ADS)

    Montzka, Carsten; Moradkhani, Hamid; Weihermüller, Lutz; Franssen, Harrie-Jan Hendricks; Canty, Morton; Vereecken, Harry

    2011-03-01

    SummaryIn a synthetic study we explore the potential of using surface soil moisture measurements obtained from different satellite platforms to retrieve soil moisture profiles and soil hydraulic properties using a sequential data assimilation procedure and a 1D mechanistic soil water model. Four different homogeneous soil types were investigated including loamy sand, loam, silt, and clayey soils. The forcing data including precipitation and potential evapotranspiration were taken from the meteorological station of Aachen (Germany). With the aid of the forward model run, a synthetic data set was designed and observations were generated. The virtual top soil moisture observations were then assimilated to update the states and hydraulic parameters of the model by means of a particle filtering data assimilation method. Our analyses include the effect of assimilation strategy, measurement frequency, accuracy in surface soil moisture measurements, and soils differing in textural and hydraulic properties. With this approach we were able to assess the value of periodic spaceborne observations of top soil moisture for soil moisture profile estimation and identify the adequate conditions (e.g. temporal resolution and measurement accuracy) for remotely sensed soil moisture data assimilation. Updating of both hydraulic parameters and state variables allowed better predictions of top soil moisture contents as compared with updating of states only. An important conclusion is that the assimilation of remotely-sensed top soil moisture for soil hydraulic parameter estimation generates a bias depending on the soil type. Results indicate that the ability of a data assimilation system to correct the soil moisture state and estimate hydraulic parameters is driven by the non linearity between soil moisture and pressure head.

  19. Applying petrophysical models to radar travel time and electrical resistivity tomograms: Resolution-dependent limitations

    USGS Publications Warehouse

    Day-Lewis, F. D.; Singha, K.; Binley, A.M.

    2005-01-01

    Geophysical imaging has traditionally provided qualitative information about geologic structure; however, there is increasing interest in using petrophysical models to convert tomograms to quantitative estimates of hydrogeologic, mechanical, or geochemical parameters of interest (e.g., permeability, porosity, water content, and salinity). Unfortunately, petrophysical estimation based on tomograms is complicated by limited and variable image resolution, which depends on (1) measurement physics (e.g., electrical conduction or electromagnetic wave propagation), (2) parameterization and regularization, (3) measurement error, and (4) spatial variability. We present a framework to predict how core-scale relations between geophysical properties and hydrologic parameters are altered by the inversion, which produces smoothly varying pixel-scale estimates. We refer to this loss of information as "correlation loss." Our approach upscales the core-scale relation to the pixel scale using the model resolution matrix from the inversion, random field averaging, and spatial statistics of the geophysical property. Synthetic examples evaluate the utility of radar travel time tomography (RTT) and electrical-resistivity tomography (ERT) for estimating water content. This work provides (1) a framework to assess tomograms for geologic parameter estimation and (2) insights into the different patterns of correlation loss for ERT and RTT. Whereas ERT generally performs better near boreholes, RTT performs better in the interwell region. Application of petrophysical models to the tomograms in our examples would yield misleading estimates of water content. Although the examples presented illustrate the problem of correlation loss in the context of near-surface geophysical imaging, our results have clear implications for quantitative analysis of tomograms for diverse geoscience applications. Copyright 2005 by the American Geophysical Union.

  20. Cumulative and residual effects of potato cropping system management strategies on crop and soil health parameters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil and crop management practices can greatly affect parameters related to soil health, as well as crop productivity and disease development, and may provide options for more sustainable production. Different 3-yr potato cropping systems focused on specific management goals of soil conservation (SC...

  1. Variations in petrophysical properties of shales along a stratigraphic section in the Whitby mudstone (UK)

    NASA Astrophysics Data System (ADS)

    Barnhoorn, Auke; Houben, Maartje; Lie-A-Fat, Joella; Ravestein, Thomas; Drury, Martyn

    2015-04-01

    In unconventional tough gas reservoirs (e.g. tight sandstones or shales) the presence of fractures, either naturally formed or hydraulically induced, is almost always a prerequisite for hydrocarbon productivity to be economically viable. One of the formations classified so far as a potential interesting formation for shale gas exploration in the Netherlands is the Lower Jurassic Posidonia Shale Formation (PSF). However data of the Posidonia Shale Formation is scarce so far and samples are hard to come by, especially on the variability and heterogeneity of the petrophysical parameters of this shale little is known. Therefore research and sample collection is conducted on a time and depositional analogue of the PSF: the Whitby Mudstone Formation (WMF) in the United Kingdom. A large number of samples along a ~7m stratigraphic section of the Whitby Mudstone Formation have been collected and analysed. Standard petrophysical properties such as porosity and matrix densities are quantified for a number of samples throughout the section, as well as mineral composition analysis based on XRD/XRF and SEM analyses. Seismic velocity measurements are also conducted at multiple heights in the section and in multiple directions to elaborate on anisotropy of the material. Attenuation anisotropy is incorporated as well as Thomsen's parameters combined with elastic parameters, e.g. Young's modulus and Poisson's ratio, to quantify the elastic anisotropy. Furthermore rock mechanical experiments are conducted to determine the elastic constants, rock strength, fracture characteristics, brittleness index, fraccability and rock mechanical anisotropy across the stratigraphic section of the Whitby mudstone formation. Results show that the WMF is highly anisotropic and it exhibits an anisotropy on the large limit of anisotropy reported for US gas shales. The high anisotropy of the Whitby shales has an even larger control on the formation of the fracture network. Furthermore, most petrophysical

  2. Predicting Soil Salinity with Vis–NIR Spectra after Removing the Effects of Soil Moisture Using External Parameter Orthogonalization

    PubMed Central

    Liu, Ya; Pan, Xianzhang; Wang, Changkun; Li, Yanli; Shi, Rongjie

    2015-01-01

    Robust models for predicting soil salinity that use visible and near-infrared (vis–NIR) reflectance spectroscopy are needed to better quantify soil salinity in agricultural fields. Currently available models are not sufficiently robust for variable soil moisture contents. Thus, we used external parameter orthogonalization (EPO), which effectively projects spectra onto the subspace orthogonal to unwanted variation, to remove the variations caused by an external factor, e.g., the influences of soil moisture on spectral reflectance. In this study, 570 spectra between 380 and 2400 nm were obtained from soils with various soil moisture contents and salt concentrations in the laboratory; 3 soil types × 10 salt concentrations × 19 soil moisture levels were used. To examine the effectiveness of EPO, we compared the partial least squares regression (PLSR) results established from spectra with and without EPO correction. The EPO method effectively removed the effects of moisture, and the accuracy and robustness of the soil salt contents (SSCs) prediction model, which was built using the EPO-corrected spectra under various soil moisture conditions, were significantly improved relative to the spectra without EPO correction. This study contributes to the removal of soil moisture effects from soil salinity estimations when using vis–NIR reflectance spectroscopy and can assist others in quantifying soil salinity in the future. PMID:26468645

  3. Predicting Soil Salinity with Vis-NIR Spectra after Removing the Effects of Soil Moisture Using External Parameter Orthogonalization.

    PubMed

    Liu, Ya; Pan, Xianzhang; Wang, Changkun; Li, Yanli; Shi, Rongjie

    2015-01-01

    Robust models for predicting soil salinity that use visible and near-infrared (vis-NIR) reflectance spectroscopy are needed to better quantify soil salinity in agricultural fields. Currently available models are not sufficiently robust for variable soil moisture contents. Thus, we used external parameter orthogonalization (EPO), which effectively projects spectra onto the subspace orthogonal to unwanted variation, to remove the variations caused by an external factor, e.g., the influences of soil moisture on spectral reflectance. In this study, 570 spectra between 380 and 2400 nm were obtained from soils with various soil moisture contents and salt concentrations in the laboratory; 3 soil types × 10 salt concentrations × 19 soil moisture levels were used. To examine the effectiveness of EPO, we compared the partial least squares regression (PLSR) results established from spectra with and without EPO correction. The EPO method effectively removed the effects of moisture, and the accuracy and robustness of the soil salt contents (SSCs) prediction model, which was built using the EPO-corrected spectra under various soil moisture conditions, were significantly improved relative to the spectra without EPO correction. This study contributes to the removal of soil moisture effects from soil salinity estimations when using vis-NIR reflectance spectroscopy and can assist others in quantifying soil salinity in the future.

  4. Quick and low cost measurement of soil parameters using a Kinect 3D scanner

    NASA Astrophysics Data System (ADS)

    Hut, R.; Van De Giesen, N.; Hagenaars, R.

    2013-12-01

    Retrieval of basic soil parameters such as bulk density and soil moisture from soil samples is a costly and time-consuming activity. Although indirect methods (heat or electromagnetic probes, radar backscatter, etc) are abundant, field truth measurement of soil parameters will remain important, if only to calibrate these other methods. We present a quick, field mountable setup to make 3D scans of surfaces up to 30 x 30 cm using a Kinect 3D scanner. By making scans before and after samples are taken, parameters such as bulk density and moisture content can easily be calculated.

  5. Soil Biological Parameters Influenced By Cocoa Management Systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cropping systems have a profound influence on the soil micro-fauna and they are responsible for nutrient cycling, and add stability to the soil. At Tarapoto, Peru, two field experiments were established on acidic medium fertility Alfisol to assess the influence of management systems on cacao rhizosp...

  6. DISTRIBUTION OF PARAMETERS DETERMINING BIOAVAILABILITY OF METALS IN EUROPEAN SOILS

    EPA Science Inventory

    As part of a program to develop a predictive model of bioavailability and toxicity of copper in soils to terrestrial organisms, 19 soils from 9 countries of the EU were collected and analyzed for use in bioavailability tests. However, it is desired that the model be of use on a ...

  7. Roughness parameter optimization using Land Parameter Retrieval Model and Soil Moisture Deficit: Implementation using SMOS brightness temperatures

    NASA Astrophysics Data System (ADS)

    Srivastava, Prashant K.; O'Neill, Peggy; Han, Dawei; Rico-Ramirez, Miguel A.; Petropoulos, George P.; Islam, Tanvir; Gupta, Manika

    2015-04-01

    Roughness parameterization is necessary for nearly all soil moisture retrieval algorithms such as single or dual channel algorithms, L-band Microwave Emission of Biosphere (LMEB), Land Parameter Retrieval Model (LPRM), etc. At present, roughness parameters can be obtained either by field experiments, although obtaining field measurements all over the globe is nearly impossible, or by using a land cover-based look up table, which is not always accurate everywhere for individual fields. From a catalogue of models available in the technical literature domain, the LPRM model was used here because of its robust nature and applicability to a wide range of frequencies. LPRM needs several parameters for soil moisture retrieval -- in particular, roughness parameters (h and Q) are important for calculating reflectivity. In this study, the h and Q parameters are optimized using the soil moisture deficit (SMD) estimated from the probability distributed model (PDM) and Soil Moisture and Ocean Salinity (SMOS) brightness temperatures following the Levenberg-Marquardt (LM) algorithm over the Brue catchment, Southwest of England, U.K.. The catchment is predominantly a pasture land with moderate topography. The PDM-based SMD is used as it is calibrated and validated using locally available ground-based information, suitable for large scale areas such as catchments. The optimal h and Q parameters are determined by maximizing the correlation between SMD and LPRM retrieved soil moisture. After optimization the values of h and Q have been found to be 0.32 and 0.15, respectively. For testing the usefulness of the estimated roughness parameters, a separate set of SMOS datasets are taken into account for soil moisture retrieval using the LPRM model and optimized roughness parameters. The overall analysis indicates a satisfactory result when compared against the SMD information. This work provides quantitative values of roughness parameters suitable for large scale applications. The

  8. Geomechanical and Petrophysical Properties of Rift Basin Mudstones

    NASA Astrophysics Data System (ADS)

    Zakharova, N. V.; Goldberg, D.; Collins, D.; Malkewicz, N.

    2015-12-01

    Mudstone caprocks are important components of reservoir systems in a variety of geologic and geoingeneering applications, but their properties and behavior under in situ conditions remain only partially understood. This study presents a detailed analysis of geomechanical and petrophysical properties of 20 lacustrine mudstones from the Mesozoic Newark Rift Basin, the largest of exposed rift basins in eastern North America, considered as a potential CO2 sequestration site. The samples were selected to represent variable lithology, organic content, redox state, structure (massive and thinly bedded), degree of matrix anisotropy, and burial depths. An extensive characterization program was funded by the U.S. Department of Energy's National Energy Technology Laboratory (NETL), and included laboratory CT scans, XRD, SEM, MICP, porosity, permeability, and acoustic velocity measurements, as well as geomechanical testing of both matrix and fracture strength under a range of confining pressures. Core measurements were integrated with available logging data to allow for multiscale comparison and correlation. Most of the analyzed mudstones have the clay content of 50-70%, with abundant mica and detrital grains. The pore system is dominated by narrow micropores (mostly <5-100 microns wide), and nano-scale pore throats (0.005-0.05 microns). Full Mohr-Coulomb failure envelopes built for each mudstone type indicate a large variability in projected unconfined strength and the coefficient of internal friction. The dataset allows building empirical relations between compositional, structural and mechanical properties of these lacustrine mudstones, as well as physical parameters such as acoustic velocity (both laboratory and logging) and elastic moduli. These relations can be applied to other lacustrine mudstones in the East American rift basins, and provide important information for caprock stability modeling in these basins.

  9. Research progress of on-the-go soil parameter sensors based on NIRS

    NASA Astrophysics Data System (ADS)

    An, Xiaofei; Meng, Zhijun; Wu, Guangwei; Guo, Jianhua

    2014-11-01

    Both the ever-increasing prices of fertilizer and growing ecological concern over chemical run-off into sources of drinking water have brought the issues of precision agriculture and site-specific management to the forefront of present technological development within agriculture and ecology. Soil is an important and basic element in agriculture production. Acquisition of soil information plays an important role in precision agriculture. The soil parameters include soil total nitrogen, phosporus, potassium, soil organic matter, soil moisture, electrical conductivity and pH value and so on. Field rapid acquisition to all the kinds of soil physical and chemical parameters is one of the most important research directions. And soil parameter real-time monitoring is also the trend of future development in precision agriculture. While developments in precision agriculture and site-specific management procedures have made significant in-roads on these issues and many researchers have developed effective means to determine soil properties, routinely obtaining robust on-the-go measurements of soil properties which are reliable enough to drive effective fertilizer application remains a challenge. NIRS technology provides a new method to obtain soil parameter with low cost and rapid advantage. In this paper, research progresses of soil on-the-go spectral sensors at domestic and abroad was combed and analyzed. There is a need for the sensing system to perform at least six key indexes for any on-the-go soil spectral sensor to be successful. The six indexes are detection limit, specificity, robustness, accuracy, cost and easy-to-use. Both the research status and problems were discussed. Finally, combining the national conditions of china, development tendency of on-the-go soil spectral sensors was proposed. In the future, on-the-go soil spectral sensors with reliable enough, sensitive enough and continuous detection would become popular in precision agriculture.

  10. Elimination of the soil moisture effect on the spectra for reflectance prediction of soil salinity using external parameter orthogonalization method

    NASA Astrophysics Data System (ADS)

    Peng, Xiang; Xu, Chi; Zeng, Wenzhi; Wu, JingWei; Huang, JieSheng

    2016-01-01

    Soil salinization is a common desertification process, especially in arid lands. Hyperspectral remote sensing of salinized soil is favored for its advantages of being efficient and inexpensive. However, soil moisture often jointly has a great influence on the soil reflectance spectra under field conditions. It is a challenge to establish a model to eliminate the effect of soil moisture and quantitatively estimate the salinity contents of slightly and moderately salt-affected soil. A controlled laboratory experiment was conducted by way of continuously monitoring changes of soil moisture and salt content, which was mainly focused on the slightly and moderately salt-affected soil. We investigated the external parameter orthogonalization (EPO) method to remove the effect of soil moisture (4 to 36% in weight base) by preprocessing soil spectral reflectance and establishing the partial least squares regression after EPO preprocessing model (EPO-PLS) to predict soil salt content. Through comparing PLS with EPO-PLS model, R2 and ratio of prediction to deviation rose from 0.604 and 1.063, respectively, to 0.874 and 2.865 for validation data. Root mean square error and bias were, respectively, reduced from 1.163 and 0.141 g/100 g to 0.718 and 0.044 g/100 g. The performance of the model after EPO algorithm preprocessing was improved significantly.

  11. Evolution of Fractal Parameters through Development Stage of Soil Crust

    NASA Astrophysics Data System (ADS)

    Ospina, Abelardo; Florentino, Adriana; Tarquis, Ana Maria

    2016-04-01

    Soil surface characteristics are subjected to changes driven by several interactions between water, air, biotic and abiotic components. One of the examples of such interactions is provided through biological soil crusts (BSC) in arid and semi-arid environments. BSC are communities composed of cyanobacteria, fungi, mosses, lichens, algae and liverworts covering the soil surface and play an important role in ecosystem functioning. The characteristics and formation of these BSC influence the soil hydrological balance, control the mass of eroded sediment, increase stability of soil surface, and influence plant productivity through the modification of nitrogen and carbon cycle. The site of this work is located at Quibor and Ojo de Agua (Lara state, Venezuela). The Quibor Depression in Venezuela is a major agricultural area being at semi-arid conditions and limited drainage favor the natural process of salinization. Additionally, the extension and intensification of agriculture has led to over-exploitation of groundwater in the past 30 years (Méndoza et al., 2013). The soil microbial crust develops initially on physical crusts which are mainly generated since wetting and drying, being a recurrent feature in the Quíbor arid zone. The microbiotic crust is organic, composed of macro organisms (bryophytes and lichens) and microorganisms (cyanobacteria, fungi algae, etc.); growing on the ground, forming a thickness no greater than 3 mm. For further details see Toledo and Florentino (2009). This study focus on characterize the development stage of the BSC based on image analysis. To this end, grayscale images of different types of biological soil crust at different stages where taken, each image corresponding to an area of 12.96 cm2 with a resolution of 1024x1024 pixels (Ospina et al., 2015). For each image lacunarity and fractal dimension through the differential box counting method were calculated. These were made with the software ImageJ/Fraclac (Karperien, 2013

  12. Toxicity assessment of two soils from Jales mine (Portugal) using plants: growth and biochemical parameters.

    PubMed

    Loureiro, Susana; Santos, Conceição; Pinto, Glória; Costa, Armando; Monteiro, Marta; Nogueira, António J A; Soares, Amadeu M V M

    2006-02-01

    Contaminants in soils can enter food chains through primary producers. Bioavailable contaminants can induce growth, and reproductive or biochemical changes in plants. To evaluate the bioavailability of heavy metals in two soils from Jales mine surroundings, bioassays with the plants Brassica rapa (RCBr) and Avena sativa were performed. Biochemical parameters (protein and malondialdehyde [MDA] content, and catalase and peroxidase activities) were also measured. The soils had different heavy metal contents: JNC soil contained low heavy metal concentrations, whereas JC soil had high heavy metal contents. Results stressed the difference between species sensitivity, with A. sativa showing no toxicity effects when exposed to both soils. On the other hand, B. rapa presented a decrease in growth parameters when exposed to JNC soil and no changes when exposed to JC soil. A Life Cycle Bioassay confirmed this trend for B. rapa exposed to JNC soil, but also evidenced that JC soil was affecting B. rapa in terms of flower and seed pod production. Biochemical assays showed that plants affected by heavy metals also displayed oxidative stress, with an increase in MDA production, reduction of protein content, and reduction of catalase and peroxidase activities. All bioassays revealed that JNC soil, although with a lower heavy metal content, had a higher bioavailable fraction when compared to JC soil, which consequently increased its toxicity to plants.

  13. Soil Parameters Drive the Structure, Diversity and Metabolic Potentials of the Bacterial Communities Across Temperate Beech Forest Soil Sequences.

    PubMed

    Jeanbille, M; Buée, M; Bach, C; Cébron, A; Frey-Klett, P; Turpault, M P; Uroz, S

    2016-02-01

    Soil and climatic conditions as well as land cover and land management have been shown to strongly impact the structure and diversity of the soil bacterial communities. Here, we addressed under a same land cover the potential effect of the edaphic parameters on the soil bacterial communities, excluding potential confounding factors as climate. To do this, we characterized two natural soil sequences occurring in the Montiers experimental site. Spatially distant soil samples were collected below Fagus sylvatica tree stands to assess the effect of soil sequences on the edaphic parameters, as well as the structure and diversity of the bacterial communities. Soil analyses revealed that the two soil sequences were characterized by higher pH and calcium and magnesium contents in the lower plots. Metabolic assays based on Biolog Ecoplates highlighted higher intensity and richness in usable carbon substrates in the lower plots than in the middle and upper plots, although no significant differences occurred in the abundance of bacterial and fungal communities along the soil sequences as assessed using quantitative PCR. Pyrosequencing analysis of 16S ribosomal RNA (rRNA) gene amplicons revealed that Proteobacteria, Acidobacteria and Bacteroidetes were the most abundantly represented phyla. Acidobacteria, Proteobacteria and Chlamydiae were significantly enriched in the most acidic and nutrient-poor soils compared to the Bacteroidetes, which were significantly enriched in the soils presenting the higher pH and nutrient contents. Interestingly, aluminium, nitrogen, calcium, nutrient availability and pH appeared to be the best predictors of the bacterial community structures along the soil sequences.

  14. Effects of hazelnut husk compost application on soil quality parameters in hazelnut orchards in Turkey

    NASA Astrophysics Data System (ADS)

    Kizilkaya, Ridvan

    2016-04-01

    The long-term application of excessive chemical fertilizers has resulted in the degeneration of soil quality parameters such as soil microbial biomass, respiration, and nutrient content, which in turn affects crop health, productivity, and soil sustainable productivity. The objective of this study was to develop a rapid and efficient solution for rehabilitating degraded two hazelnut orchards having different textures by precisely quantifying soil quality parameters through the application of different doses (0, 1.25, 2.5, 5.0, 7.5 and 10 ton da-1) of hazelnut husk compost (HH) during hazelnut growth. After nine months of HHC application, soil quality parameters such as microbial biomass carbon (Cmic), basal respiration (BSR), total organic carbon (Corg), total N, C/N ratio, aggregate stability and some soil chemical properties (pH, EC and NO3-N content) were carried out on collected soil samples. The results showed that soil quality parameters were significantly affected by soil texture and HHC application doses. In general, Cmic, BSR, C/N ratio and the contents of Corg and N increased (P<0,001) and Cmic/Corg values decreased (P<0,001) with increasing HHC application in comparison with the control. In addition, HHC markedly increased the contents of NO3-N, the aggregate stability of soil, and the hydrolic conductivity in the soil were notably heightened. According to the results of field experiments conducted different location and condition, when the focusing on the organic substance management and sustainability of the quality parameters in soil, it was clear from the evidence obtained the research that the ideal HHC application was 5 ton per decare to increase the organic matter content by 2%. (This research was supported by The Scientific and Technological Research Council of Turkey, Project number: 111O698).

  15. Evaluation of the Parameters of Radioactive Contamination of Soils

    SciTech Connect

    Panasyuk M.I.; Skorbun A.D.; Klyuchnikov O.O.

    2002-02-26

    After Chornobyl NPP (ChNPP) accident the territory near destroyed Unit 4 (that now with the special confinement has the name the ''Shelter'' object) is contaminated of fuel fallouts. During liquidation of the accident consequences this territory was covered with pure earth, concrete, etc. As a result a contaminated anthropogenic layer of the soil on the depth up to 10 m was formed. Now the problem of contamination estimation and the soils management arose. For this tasks a gamma logging method was modified conformably to ChNPP conditions. The methods for necessary coefficients receiving and log treatment have been suggested.

  16. Effects of soil temperature on parameters of a coupled photosynthesis-stomatal conductance model.

    PubMed

    Cai, Tiebo; Dang, Qing-Lai

    2002-08-01

    To examine the effects of soil temperature on a coupled photosynthesis-stomatal conductance model, seedlings of trembling aspen (Populus tremuloides Michx.), jack pine (Pinus banksiana Lamb.), black spruce (Picea Mariana (Mill.) B.S.P.) and white spruce (Picea glauca (Moench) Voss) were exposed to soil temperatures ranging from 5 to 35 degrees C for 4 months. Light and CO(2) response curves of foliar gas exchange were measured for model parameterization. The effects of soil temperature on four key model parameters, V(cmax) (maximum rate of carboxylation), J(max) (maximum rate of electron transport), alpha (energy conversion efficiency or quantum efficiency of electron transport) and R(d) (daytime dark respiration), were modeled using two third-order polynomial equations and a modified Arrhenius equation. In all species, V(cmax) and J(max) increased with soil temperature up to an optimum, and then decreased with further increases in soil temperature. In the conifers, alpha showed a similar response to soil temperature as V(cmax) and J(max), but soil temperature had no significant effect on alpha in aspen. Soil temperature had no significant effect on R(d) in any species. The three equations described the relationships between soil temperature and the model parameters reasonably well, but performed best for V(cmax) and worst for alpha. No significant relationships were identified between soil temperature and the parameters of the stomatal conductance model. PMID:12184971

  17. Soil-skin adherence from carpet: use of a mechanical chamber to control contact parameters.

    PubMed

    Ferguson, Alesia C; Bursac, Zoran; Biddle, Deborah; Coleman, Sheire; Johnson, Wayne

    2008-10-01

    A computer-controlled mechanical chamber was used to control the contact between carpet samples laden with soil, and human cadaver skin and cotton sheet samples for the measurement of mass soil transfer. Mass soil transfers were converted to adherence factors (mg/cm2) for use in models that estimate dermal exposure to contaminants found in soil media. The contact parameters of pressure (10 to 50 kPa) and time (10 to 50 sec) were varied for 369 experiments of mass soil transfer, where two soil types (play sand and lawn soil) and two soil sizes (< 139.7 microm and > or = 139.7 < 381) were used. Chamber probes were used to record temperature and humidity. Log transformation of the sand/soil transfers was performed to normalize the distribution. Estimated adjusted means for experimental conditions were exponentiated in order to express them in the original units. Mean soil mass transfer to cadaver skin (0.74 mg/cm2) was higher than to cotton sheets (0.21 mg/cm2). Higher pressure (p < 0.0001), and larger particle size (p < 0.0001) were also all associated with larger amounts of soil transfer. The original model was simplified into two by adherence material type (i.e., cadaver skin and cotton sheets) in order to investigate the differential effects of pressure, time, soil size, and soil type on transfer. This research can be used to improve estimates of dermal exposure to contaminants found in home carpets.

  18. EVALUATING SOIL EROSION PARAMETER ESTIMATES FROM DIFFERENT DATA SOURCES

    EPA Science Inventory

    Topographic factors and soil loss estimates that were derived from thee data sources (STATSGO, 30-m DEM, and 3-arc second DEM) were compared. Slope magnitudes derived from the three data sources were consistently different. Slopes from the DEMs tended to provide a flattened sur...

  19. Predicted Infiltration for Sodic/Saline Soils from Reclaimed Coastal Areas: Sensitivity to Model Parameters

    PubMed Central

    She, Dongli; Yu, Shuang'en; Shao, Guangcheng

    2014-01-01

    This study was conducted to assess the influences of soil surface conditions and initial soil water content on water movement in unsaturated sodic soils of reclaimed coastal areas. Data was collected from column experiments in which two soils from a Chinese coastal area reclaimed in 2007 (Soil A, saline) and 1960 (Soil B, nonsaline) were used, with bulk densities of 1.4 or 1.5 g/cm3. A 1D-infiltration model was created using a finite difference method and its sensitivity to hydraulic related parameters was tested. The model well simulated the measured data. The results revealed that soil compaction notably affected the water retention of both soils. Model simulations showed that increasing the ponded water depth had little effect on the infiltration process, since the increases in cumulative infiltration and wetting front advancement rate were small. However, the wetting front advancement rate increased and the cumulative infiltration decreased to a greater extent when θ0 was increased. Soil physical quality was described better by the S parameter than by the saturated hydraulic conductivity since the latter was also affected by the physical chemical effects on clay swelling occurring in the presence of different levels of electrolytes in the soil solutions of the two soils. PMID:25197699

  20. Relationship between genetic parameters in maize (Zea mays) with seedling growth parameters under 40-100% soil moisture conditions.

    PubMed

    Muhammad, R W; Qayyum, A

    2013-10-18

    We estimated the association of genetic parameters with production characters in 64 maize (Zea mays) genotypes in a green house in soil with 40-100% moisture levels (percent of soil moisture capacity). To identify the major parameters that account for variation among the genotypes, we used single linkage cluster analysis and principle component analysis. Ten plant characters were measured. The first two, four, three, and again three components, with eigen values > 1 contributed 75.05, 80.11, 68.67, and 75.87% of the variability among the genotypes under the different moisture levels, i.e., 40, 60, 80, and 100%, respectively. Other principal components (3-10, 5-10, and 4-10) had eigen values less than 1. The highest estimates of heritability were found for root fresh weight, root volume (0.99), and shoot fresh weight (0.995) in 40% soil moisture. Values of genetic advance ranged from 23.4024 for SR at 40% soil moisture to 0.2538 for shoot dry weight in 60% soil moisture. The high magnitude of broad sense heritability provides evidence that these plant characters are under the control of additive genetic effects. This indicates that selection should lead to fast genetic improvement of the material. The superior agronomic types that we identified may be exploited for genetic potential to improve yield potential of the maize crop.

  1. Deriving parameters of a fundamental detachment model for cohesive soils from flume and jet erosion tests

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The erosion rate of cohesive soils is commonly quantified using the excess shear stress equation, dependent on two major soil parameters: the critical shear stress and the erodibility coefficient. A submerged jet test (JET – Jet Erosion Test) is one method that has been developed for measuring thes...

  2. Likelihood parameter estimation for calibrating a soil moisture using radar backscatter

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Assimilating soil moisture information contained in synthetic aperture radar imagery into land surface model predictions can be done using a calibration, or parameter estimation, approach. The presence of speckle, however, necessitates aggregating backscatter measurements over large land areas in or...

  3. Deforestation effects on soil quality and water retention curve parameters in eastern Ardabil, Iran

    NASA Astrophysics Data System (ADS)

    Asghari, Sh.; Ahmadnejad, S.; Keivan Behjou, F.

    2016-03-01

    The land use change from natural to managed ecosystems causes serious soil degradation. The main objective of this research was to assess deforestation effects on soil physical quality attributes and soil water retention curve (SWRC) parameters in the Fandoghlou region of Ardabil province, Iran. Totally 36 surface and subsurface soil samples were taken and soil water contents measured at 13 suctions. Alfa (α) and n parameters in van Genuchten (1980) model were estimated by fitting SWRC data by using RETC software. The slope of SWRC at inflection point (SP) was calculated by Dexter (2004) equation. The results indicated that with changing land use from forest (F) to range land (R) and cultivated land (C), and also with increasing soil depth from 0-25 to 75-100 cm in each land use, organic carbon, micropores, saturated and available water contents decreased and macropores and bulk density increased significantly ( P < 0.05). The position of SWRC shape in F was higher than R and C lands at all soil depths. Changing F to R and C lands and also increasing soil depth in each land use significantly ( P < 0.05) increased α and decreased n and SP. The average values of SP were obtained 0.093, 0.051 and 0.031 for F, R and C, respectively. As a result, deforestation reduced soil physical quality by affecting SWRC parameters.

  4. Surface Roughness Parameter Uncertainties on Radar Based Soil Moisture Retrievals

    NASA Technical Reports Server (NTRS)

    Joseph, A. T.; vanderVelde, R.; O'Neill, P. E.; Lang, R.; Su, Z.; Gish, T.

    2012-01-01

    Surface roughness variations are often assumed to be negligible for the retrieval of sol moisture. Although previous investigations have suggested that this assumption is reasonable for natural vegetation covers (i.e. Moran et al. 2002), in-situ measurements over plowed agricultural fields (i.e. Callens et al. 2006) have shown that the soil surface roughness can change considerably due to weathering induced by rain.

  5. Assessment of SMOS soil moisture retrieval parameters using tau-omega algorithms for soil moisture deficit estimation

    NASA Astrophysics Data System (ADS)

    Srivastava, Prashant K.; Han, Dawei; Rico-Ramirez, Miguel A.; O'Neill, Peggy; Islam, Tanvir; Gupta, Manika

    2014-11-01

    Soil Moisture and Ocean Salinity (SMOS) is the latest mission which provides flow of coarse resolution soil moisture data for land applications. However, the efficient retrieval of soil moisture for hydrological applications depends on optimally choosing the soil and vegetation parameters. The first stage of this work involves the evaluation of SMOS Level 2 products and then several approaches for soil moisture retrieval from SMOS brightness temperature are performed to estimate Soil Moisture Deficit (SMD). The most widely applied algorithm i.e. Single channel algorithm (SCA), based on τ-ω is used in this study for the soil moisture retrieval. In τ-ω, the soil moisture is retrieved using the Horizontal (H) polarisation following Hallikainen dielectric model, roughness parameters, Fresnel's equation and estimated Vegetation Optical Depth (τ). The roughness parameters are empirically calibrated using the numerical optimization techniques. Further to explore the improvement in retrieval models, modifications have been incorporated in the algorithms with respect to the sources of the parameters, which include effective temperatures derived from the European Center for Medium-Range Weather Forecasts (ECMWF) downscaled using the Weather Research and Forecasting (WRF)-NOAH Land Surface Model and Moderate Resolution Imaging Spectroradiometer (MODIS) land surface temperature (LST) while the τ is derived from MODIS Leaf Area Index (LAI). All the evaluations are performed against SMD, which is estimated using the Probability Distributed Model following a careful calibration and validation integrated with sensitivity and uncertainty analysis. The performance obtained after all those changes indicate that SCA-H using WRF-NOAH LSM downscaled ECMWF LST produces an improved performance for SMD estimation at a catchment scale.

  6. Assessment of SMOS Soil Moisture Retrieval Parameters Using Tau-Omega Algorithms for Soil Moisture Deficit Estimation

    NASA Technical Reports Server (NTRS)

    Srivastava, Prashant K.; Han, Dawei; Rico-Ramirez, Miguel A.; O'Neill, Peggy; Islam, Tanvir; Gupta, Manika

    2014-01-01

    Soil Moisture and Ocean Salinity (SMOS) is the latest mission which provides flow of coarse resolution soil moisture data for land applications. However, the efficient retrieval of soil moisture for hydrological applications depends on optimally choosing the soil and vegetation parameters. The first stage of this work involves the evaluation of SMOS Level 2 products and then several approaches for soil moisture retrieval from SMOS brightness temperature are performed to estimate Soil Moisture Deficit (SMD). The most widely applied algorithm i.e. Single channel algorithm (SCA), based on tau-omega is used in this study for the soil moisture retrieval. In tau-omega, the soil moisture is retrieved using the Horizontal (H) polarisation following Hallikainen dielectric model, roughness parameters, Fresnel's equation and estimated Vegetation Optical Depth (tau). The roughness parameters are empirically calibrated using the numerical optimization techniques. Further to explore the improvement in retrieval models, modifications have been incorporated in the algorithms with respect to the sources of the parameters, which include effective temperatures derived from the European Center for Medium-Range Weather Forecasts (ECMWF) downscaled using the Weather Research and Forecasting (WRF)-NOAH Land Surface Model and Moderate Resolution Imaging Spectroradiometer (MODIS) land surface temperature (LST) while the s is derived from MODIS Leaf Area Index (LAI). All the evaluations are performed against SMD, which is estimated using the Probability Distributed Model following a careful calibration and validation integrated with sensitivity and uncertainty analysis. The performance obtained after all those changes indicate that SCA-H using WRF-NOAH LSM downscaled ECMWF LST produces an improved performance for SMD estimation at a catchment scale.

  7. Responses of Water and Salt Parameters to Groundwater Levels for Soil Columns Planted with Tamarix chinensis.

    PubMed

    Xia, Jiangbao; Zhao, Ximei; Chen, Yinping; Fang, Ying; Zhao, Ziguo

    2016-01-01

    Groundwater is the main water resource for plant growth and development in the saline soil of the Yellow River Delta in China. To investigate the variabilities and distributions of soil water and salt contents at various groundwater level (GL), soil columns with planting Tamarix chinensis Lour were established at six different GL. The results demonstrated the following: With increasing GL, the relative soil water content (RWC) declined significantly, whereas the salt content (SC) and absolute soil solution concentration (CS) decreased after the initial increase in the different soil profiles. A GL of 1.2 m was the turning point for variations in the soil water and salt contents, and it represented the highest GL that could maintain the soil surface moist within the soil columns. Both the SC and CS reached the maximum levels in these different soil profiles at a GL of 1.2 m. With the raise of soil depth, the RWC increased significantly, whereas the SC increased after an initial decrease. The mean SC values reached 0.96% in the top soil layer; however, the rates at which the CS and RWC decreased with the GL were significantly reduced. The RWC and SC presented the greatest variations at the medium (0.9-1.2 m) and shallow water levels (0.6 m) respectively, whereas the CS presented the greatest variation at the deep water level (1.5-1.8 m).The RWC, SC and CS in the soil columns were all closely related to the GL. However, the correlations among the parameters varied greatly within different soil profiles, and the most accurate predictions of the GL were derived from the RWC in the shallow soil layer or the SC in the top soil layer. A GL at 1.5-1.8 m was moderate for planting T. chinensis seedlings under saline groundwater conditions.

  8. Responses of Water and Salt Parameters to Groundwater Levels for Soil Columns Planted with Tamarix chinensis

    PubMed Central

    Xia, Jiangbao; Zhao, Ximei; Chen, Yinping; Fang, Ying; Zhao, Ziguo

    2016-01-01

    Groundwater is the main water resource for plant growth and development in the saline soil of the Yellow River Delta in China. To investigate the variabilities and distributions of soil water and salt contents at various groundwater level (GL), soil columns with planting Tamarix chinensis Lour were established at six different GL. The results demonstrated the following: With increasing GL, the relative soil water content (RWC) declined significantly, whereas the salt content (SC) and absolute soil solution concentration (CS) decreased after the initial increase in the different soil profiles. A GL of 1.2 m was the turning point for variations in the soil water and salt contents, and it represented the highest GL that could maintain the soil surface moist within the soil columns. Both the SC and CS reached the maximum levels in these different soil profiles at a GL of 1.2 m. With the raise of soil depth, the RWC increased significantly, whereas the SC increased after an initial decrease. The mean SC values reached 0.96% in the top soil layer; however, the rates at which the CS and RWC decreased with the GL were significantly reduced. The RWC and SC presented the greatest variations at the medium (0.9–1.2 m) and shallow water levels (0.6 m) respectively, whereas the CS presented the greatest variation at the deep water level (1.5–1.8 m).The RWC, SC and CS in the soil columns were all closely related to the GL. However, the correlations among the parameters varied greatly within different soil profiles, and the most accurate predictions of the GL were derived from the RWC in the shallow soil layer or the SC in the top soil layer. A GL at 1.5–1.8 m was moderate for planting T. chinensis seedlings under saline groundwater conditions. PMID:26730602

  9. Soybean fungal soil-borne diseases: a parameter for measuring the effect of agricultural intensification on soil health.

    PubMed

    Pérez-Brandán, C; Huidobro, J; Grümberg, B; Scandiani, M M; Luque, A G; Meriles, J M; Vargas-Gil, S

    2014-02-01

    The aim of this study was to investigate the influence of agricultural intensification on soil microbial diversity, chemical and physical parameters, and the decrease of the incidence of sudden death syndrome (Fusarium crassistipitatum) and charcoal rot (Macrophomina phaseolina) in soybean. Soils under different management systems were evaluated during 2 crop cycles: soybean monoculture for 24 and 11 years, soybean-maize rotation for 15 and 4 years, 1 year of soybean, and native vegetation. The incidence of both soil-borne diseases was higher under monoculture than under rotation. Increased populations of potential biocontrol agents (Trichoderma spp., Gliocladium spp., fluorescent pseudomonads) were associated with rotation treatments, especially in 2010-2011. The comparison of agricultural vs. native vegetation soil and the average of agricultural cycles showed that microbial biomass carbon and glomalin-related soil protein were higher in the rotation system than in monoculture (50% and 77%, respectively). Furthermore, from the community-level functional diversity (Biolog Eco plates), McIntosh index showed lower functional diversity in monoculture than in rotation and native vegetation plots. Agricultural intensification reduced microbial biomass carbon, glomalin-related soil protein, organic matter, total nitrogen, aggregate stability, and yield, and increased bulk density. Soil quality degradation was associated with the establishment of soil-borne pathogens and increased soybean plant susceptibility to disease.

  10. Soybean fungal soil-borne diseases: a parameter for measuring the effect of agricultural intensification on soil health.

    PubMed

    Pérez-Brandán, C; Huidobro, J; Grümberg, B; Scandiani, M M; Luque, A G; Meriles, J M; Vargas-Gil, S

    2014-02-01

    The aim of this study was to investigate the influence of agricultural intensification on soil microbial diversity, chemical and physical parameters, and the decrease of the incidence of sudden death syndrome (Fusarium crassistipitatum) and charcoal rot (Macrophomina phaseolina) in soybean. Soils under different management systems were evaluated during 2 crop cycles: soybean monoculture for 24 and 11 years, soybean-maize rotation for 15 and 4 years, 1 year of soybean, and native vegetation. The incidence of both soil-borne diseases was higher under monoculture than under rotation. Increased populations of potential biocontrol agents (Trichoderma spp., Gliocladium spp., fluorescent pseudomonads) were associated with rotation treatments, especially in 2010-2011. The comparison of agricultural vs. native vegetation soil and the average of agricultural cycles showed that microbial biomass carbon and glomalin-related soil protein were higher in the rotation system than in monoculture (50% and 77%, respectively). Furthermore, from the community-level functional diversity (Biolog Eco plates), McIntosh index showed lower functional diversity in monoculture than in rotation and native vegetation plots. Agricultural intensification reduced microbial biomass carbon, glomalin-related soil protein, organic matter, total nitrogen, aggregate stability, and yield, and increased bulk density. Soil quality degradation was associated with the establishment of soil-borne pathogens and increased soybean plant susceptibility to disease. PMID:24498984

  11. Micro- and macro-scale petrophysical characterization of potential reservoir units from the Northern Israel

    NASA Astrophysics Data System (ADS)

    Haruzi, Peleg; Halisch, Matthias; Katsman, Regina; Waldmann, Nicolas

    2016-04-01

    Lower Cretaceous sandstone serves as hydrocarbon reservoir in some places over the world, and potentially in Hatira formation in the Golan Heights, northern Israel. The purpose of the current research is to characterize the petrophysical properties of these sandstone units. The study is carried out by two alternative methods: using conventional macroscopic lab measurements, and using CT-scanning, image processing and subsequent fluid mechanics simulations at a microscale, followed by upscaling to the conventional macroscopic rock parameters (porosity and permeability). Comparison between the upscaled and measured in the lab properties will be conducted. The best way to upscale the microscopic rock characteristics will be analyzed based the models suggested in the literature. Proper characterization of the potential reservoir will provide necessary analytical parameters for the future experimenting and modeling of the macroscopic fluid flow behavior in the Lower Cretaceous sandstone.

  12. A novel method for estimating the track-soil parameters based on Kalman and improved strong tracking filters.

    PubMed

    Yao, Yu; Cheng, Kai; Zhou, Zhi-Jie; Zhang, Bang-Cheng; Dong, Chao; Zheng, Sen

    2015-11-01

    A tracked vehicle has been widely used in exploring unknown environments and military fields. In current methods for suiting soil conditions, soil parameters need to be given and the traction performance cannot always be satisfied on soft soil. To solve the problem, it is essential to estimate track-soil parameters in real-time. Therefore, a detailed mathematical model is proposed for the first time. Furthermore, a novel algorithm which is composed of Kalman filter (KF) and improved strong tracking filter (STF) is developed for online track-soil estimation and named as KF-ISTF. By this method, the KF is used to estimate slip parameters, and the ISTF is used to estimate motion states. Then the key soil parameters can be estimated by using a suitable soil model. The experimental results show that equipped with the estimation algorithm, the proposed model can be used to estimate the track-soil parameters, and make the traction performance satisfied with soil conditions.

  13. Identification of sensitive parameters in the modeling of SVOC reemission processes from soil to atmosphere.

    PubMed

    Loizeau, Vincent; Ciffroy, Philippe; Roustan, Yelva; Musson-Genon, Luc

    2014-09-15

    Semi-volatile organic compounds (SVOCs) are subject to Long-Range Atmospheric Transport because of transport-deposition-reemission successive processes. Several experimental data available in the literature suggest that soil is a non-negligible contributor of SVOCs to atmosphere. Then coupling soil and atmosphere in integrated coupled models and simulating reemission processes can be essential for estimating atmospheric concentration of several pollutants. However, the sources of uncertainty and variability are multiple (soil properties, meteorological conditions, chemical-specific parameters) and can significantly influence the determination of reemissions. In order to identify the key parameters in reemission modeling and their effect on global modeling uncertainty, we conducted a sensitivity analysis targeted on the 'reemission' output variable. Different parameters were tested, including soil properties, partition coefficients and meteorological conditions. We performed EFAST sensitivity analysis for four chemicals (benzo-a-pyrene, hexachlorobenzene, PCB-28 and lindane) and different spatial scenari (regional and continental scales). Partition coefficients between air, solid and water phases are influent, depending on the precision of data and global behavior of the chemical. Reemissions showed a lower variability to soil parameters (soil organic matter and water contents at field capacity and wilting point). A mapping of these parameters at a regional scale is sufficient to correctly estimate reemissions when compared to other sources of uncertainty.

  14. Effect of the physicochemical parameters of soils on the biological availability of natural and radioactive zinc

    NASA Astrophysics Data System (ADS)

    Anisimov, V. S.; Kochetkov, I. V.; Dikarev, D. V.; Anisimova, L. N.; Korneev, Yu. N.; Frigidova, L. M.

    2016-08-01

    The relationship between the main physicochemical properties of soils and the accumulation of natural Zn and 65Zn radionuclide has been studied, and the capacity of soils to limit the mobility of the element in the soil-plant system has been assessed. The contribution of each of the selected soil state parameters to the accumulation of zinc by barley has been determined, and the soil state parameters have been ranked. It has been found that the largest contributions to the variation of the resulting parameter (65Zn accumulation coefficient, K a) are made by mobile Fe (25%), free carbonates (21%), and acid-soluble Zn (18%). The largest contributions to the Znac K a are made by free carbonates (13%) and mobile Fe (8%). The contributions of physical clay and organic carbon in soils and qualitative composition of humic substances are almost similar (4% for each). No differences in the inactivating capacity of different soils (soddy-podzolic soils, gray forest soils, and chernozems) for 65Zn are observed. This is related to the fact that the transfer of 65Zn to plants is statistically significantly controlled by the contents of free carbonates, mobile iron, and potentially plantavailable forms of stable natural Zn (carrier of 65Zn) rather than the quantitative and qualitative composition of organic matter and the degree of dispersion of mineral particles. The analysis of the Znac K a/65Zn K a ratios has shown that the share of plant-available Zn in the acid-soluble form of the metal (1 M HCl) is 0.61 on the average for the studied soils, and its share in the total Zn content in the soils is only 0.14.

  15. Retrieving Vegetation Parameters and Soil Reflection Coefficients with P-band SAR Polarimetry

    NASA Astrophysics Data System (ADS)

    Alemohammad, S. H.; Konings, A. G.; Jagdhuber, T.; Entekhabi, D.

    2015-12-01

    Photosynthetic activity of plants is highly dependent on the water available to the plant through its roots. Therefore, measuring the root-zone-soil-moisture across large spatial scales is of great importance for crop monitoring and yield estimation as well as hydrological and ecological modeling. Unlike L-band instruments, which are sensitive to only a few centimeters of the top soil layer, P-band Synthetic Aperture Radar (SAR) instruments have a penetration depth that can be used to retrieve soil moisture profiles in depths of several tens of centimeters (depending on soil texture and moisture content). NASA's Airborne Microwave Observatory of Subcanopy and Subsurface (AirMOSS) mission is designed to study the application of P-band SAR measurements for monitoring root-zone-soil-moisture. In this study, we introduce a new framework to retrieve vegetation parameters and smooth-surface soil reflection coefficients using SAR polarimetry and the fully polarimetric covariance matrix of the backscattering signal from AirMOSS observations. The retrieved soil reflectivities (both horizontally and vertically -polarized) can then be used to estimate the soil moisture profile. The retrieval model takes into account contributions from surface, dihedral and volume scattering coming from the vegetation and soil components, and does not require prior vegetation parameters. This approach reduces the dependency of the retrieval on allometry-based vegetation models with large numbers of uncertain parameters. The performance of this method will be validated using observations from AirMOSS field campaigns in July 2013 over Harvard Forest in Massachusetts, USA. This will enable a quality assessment of the polarimetry-based retrieval of the soil reflectivities and the estimated root-zone-soil-moisture profiles.

  16. Analyzing model uncertainty in predicted surface fluxes resulting from prescribed soil and vegetation parameters

    NASA Astrophysics Data System (ADS)

    Jankov, M.; Prochaka, L.; Mölders, N.

    2003-12-01

    The atmosphere and land-surface continuously interact, for which the surface affects current weather and climate. The biosphere-soil system plays an important role because it is the media in those interactions. The processes that describe those interactions are the exchange of momentuum, heat, water vapor, and matter. To include these processes at the soil-biosphere-atmosphere interface in atmospheric models they have to be parameterized. The different vegetation and soil types are realized by prescribed plant physiological and soil physical parameters (e.g. soil hydraulic conductivity, soil thermal conductivity, porosity, pore-size distribution index, leaf area index, albedo and emissivity of the foliage and soil, minimum stomatal resistance, canopy height, etc.) in these parameterizations. The parameters can vary even among the same soil or plant type. The order of magnitude of those variations can be as much as the mean values of the parameters themselves. In order to improve weather prediction the model uncertainty, caused by the necessity to prescribe parameters, has to be minimized. To asses the errors uncertainty analysis with respect to the prescribed parameters is carried out using the Gaussian Error Propagation method. We use the PennState/NCAR mesoscale meteorological model MM5 coupled with the Oregon State University land surface model (OSULSM) as the test-platform. The Gaussian Error Propagation technique provides error bars for the fluxes simulated by MM5. Moreover, the technique can point out which parameters contribute the most to the error, and should be replaced in future model development. Our preliminary results show that throughout the domain errors were at low or moderate levels. The highest errors predicted appear to be associated with scarcely vegetated, sandy clay loam areas and areas covered by ice and snow.

  17. Relation between various soil phosphorus extraction methods and sorption parameters in calcareous soils with different texture.

    PubMed

    Jalali, Mohsen; Jalali, Mahdi

    2016-10-01

    The aim of this study was to investigate the influence of soil texture on phosphorus (P) extractability and sorption from a wide range of calcareous soils across Hamedan, western Iran. Fifty seven soil samples were selected and partitioned into five types on the basis of soil texture (clay, sandy, sandy clay loam, sandy loam and mixed loam) and the P extracted with calcium chloride (PCaCl2), citrate (Pcitrate), HCl (PHCl), Olsen (POls), and Mehlich-3 (PM3) solutions. On the average, the P extracted was in the order PHCl>PM3>Pcitrate>POls>PCaCl2. The P extracted by Pcitrate, PHCl, POls, and PM3 methods were significantly higher in sandy, sandy clay loam and sandy loam textures than clay and mixed loam textures, while soil phosphorus buffer capacity (PBC) was significantly higher in clay and mixed loam soil textures. The correlation analysis revealed a significant positive relationship between silt content Freundlich sorption coefficient (KF), maximum P sorption (Qmax), linear distribution coefficient (Kd), and PBC. All extractions were highly correlated with each other and among soil components with silt content. The principal component analysis (PCA) performed on data identified five principal components describing 74.5% of total variation. The results point to soil texture as an important factor and that silt was the crucial soil property associated with P sorption and its extractability in these calcareous soils. DPSM3-2 (PM3PM3+Qmax×100) and DPScitrate (PcitratePcitrate+Qmax×100) proved to be good indicators of soil's potential P release in these calcareous soils. Among the DPS, 21% of soils reported DPSM3-2, values higher than the environmental threshold, indicating build-up of P and P release. Most of the studied sandy clay loam soils had exceeded the environmentally unacceptable P concentration. Various management practices should be taken into account to reduce P losses from these soils. Further inorganic and organic P fertilizer inputs should be reduced

  18. Relation between various soil phosphorus extraction methods and sorption parameters in calcareous soils with different texture.

    PubMed

    Jalali, Mohsen; Jalali, Mahdi

    2016-10-01

    The aim of this study was to investigate the influence of soil texture on phosphorus (P) extractability and sorption from a wide range of calcareous soils across Hamedan, western Iran. Fifty seven soil samples were selected and partitioned into five types on the basis of soil texture (clay, sandy, sandy clay loam, sandy loam and mixed loam) and the P extracted with calcium chloride (PCaCl2), citrate (Pcitrate), HCl (PHCl), Olsen (POls), and Mehlich-3 (PM3) solutions. On the average, the P extracted was in the order PHCl>PM3>Pcitrate>POls>PCaCl2. The P extracted by Pcitrate, PHCl, POls, and PM3 methods were significantly higher in sandy, sandy clay loam and sandy loam textures than clay and mixed loam textures, while soil phosphorus buffer capacity (PBC) was significantly higher in clay and mixed loam soil textures. The correlation analysis revealed a significant positive relationship between silt content Freundlich sorption coefficient (KF), maximum P sorption (Qmax), linear distribution coefficient (Kd), and PBC. All extractions were highly correlated with each other and among soil components with silt content. The principal component analysis (PCA) performed on data identified five principal components describing 74.5% of total variation. The results point to soil texture as an important factor and that silt was the crucial soil property associated with P sorption and its extractability in these calcareous soils. DPSM3-2 (PM3PM3+Qmax×100) and DPScitrate (PcitratePcitrate+Qmax×100) proved to be good indicators of soil's potential P release in these calcareous soils. Among the DPS, 21% of soils reported DPSM3-2, values higher than the environmental threshold, indicating build-up of P and P release. Most of the studied sandy clay loam soils had exceeded the environmentally unacceptable P concentration. Various management practices should be taken into account to reduce P losses from these soils. Further inorganic and organic P fertilizer inputs should be reduced

  19. [Hyperspectral parameters and prediction model of soil moisture in coastal saline].

    PubMed

    Li, Chen; Zhang, Guo-wei; Zhou, Zhi-guo; Zhao, Wen-qing; Meng, Ya-li; Chen, Bing-lin; Wang, You-hua

    2016-02-01

    Based on the data of soil moisture content and indoor soil surface spectral reflectance from five sampling sites of coastal saline soil, this paper analyzed the relationship between soil moisture content and soil spectrum in wavelength 350-2500 nm. We determined spectral parameters under ratio spectral index (RSI), normalized difference spectral index (NDSI) and difference spectral index (DI), and established the quantitative model of soil moisture content. The results showed significant negative correlation between spectral reflectance and soil moisture content, and the maximum negative correlation was near 1930 nm (r=0.86). By comparison of the regression equation of RSI, NDSI and DI, it was found that the regression equation of exponential function (y=0.00001e9.7203x) built by soil moisture content based on RSI (R1407, R1459) presented the maximum R2 (0.780) and the minimum SE (0.016). The established model based on RSI (R1407, R1459) could be used to monitor soil moisture content accurately in Jiangsu coastal saline soils.

  20. [Hyperspectral parameters and prediction model of soil moisture in coastal saline].

    PubMed

    Li, Chen; Zhang, Guo-wei; Zhou, Zhi-guo; Zhao, Wen-qing; Meng, Ya-li; Chen, Bing-lin; Wang, You-hua

    2016-02-01

    Based on the data of soil moisture content and indoor soil surface spectral reflectance from five sampling sites of coastal saline soil, this paper analyzed the relationship between soil moisture content and soil spectrum in wavelength 350-2500 nm. We determined spectral parameters under ratio spectral index (RSI), normalized difference spectral index (NDSI) and difference spectral index (DI), and established the quantitative model of soil moisture content. The results showed significant negative correlation between spectral reflectance and soil moisture content, and the maximum negative correlation was near 1930 nm (r=0.86). By comparison of the regression equation of RSI, NDSI and DI, it was found that the regression equation of exponential function (y=0.00001e9.7203x) built by soil moisture content based on RSI (R1407, R1459) presented the maximum R2 (0.780) and the minimum SE (0.016). The established model based on RSI (R1407, R1459) could be used to monitor soil moisture content accurately in Jiangsu coastal saline soils. PMID:27396127

  1. Improved Artificial Neural Network-Pedotransfer Functions (ANN-PTFs) for Estimating Soil Hydraulic Parameters

    NASA Astrophysics Data System (ADS)

    Gautam, M. R.; Zhu, J.; Ye, M.; Meyer, P. D.; Hassan, A. E.

    2008-12-01

    ANN-PTFs have become popular means of mapping easily available soil data into hard-to-measure soil hydraulic parameters in the recent years. These parameters and their distributions are the indispensable inputs to subsurface flow and transport models which provide basis for environmental planning, management and decision making. While improved ANN prediction together with the preservation of probability distributions of hydraulic parameters in ANN training is important, ANN-PTFs have been typically found using conventional ANN training approach with the mean square error as an error function, which may not preserve the probability distribution of the parameters. Moreover, the conventional ANN training can itself introduce correlation among predicted parameters and could not preserve the actual correlation among the measured parameters. The present study describes approaches to deal with such shortcomings of conventional ANN- PTF training algorithms by using new types of error functions and presents a group of improved ANN-PTF models developed on the basis of the new approaches with different levels of data availability. In the study, the bootstrap method is used as part of ANN-PTF development for generating independent training and validation sets, and calculating uncertainty estimates of the ANN predictions. The results demonstrate the merit of the new approaches of the ANN training and the physical significance of various types of less costly soil data in the prediction of soil hydraulic parameters.

  2. Gas Transport Parameters for Landfill Cover Soils: Effects of Soil Compaction and Water Blockages

    NASA Astrophysics Data System (ADS)

    Wickramarachchi, P. N.; Hamamoto, S.; Kawamoto, K.; Nawagamuwa, U.; Komatsu, T.; Moldrup, P.

    2009-12-01

    Recently, landfill sites have been emerging in greenhouse warming scenarios as a significant source of atmospheric CH4. landfill management strategies have mainly addressed the problem of preventing groundwater contamination and reduction of leachate generation. Being one of the largest source of anthropogenic CH4 emission , the final cover system should also be designed for minimizing the biogas migration into the atmosphere or the areas surrounding the landfill. Compared to the intensive research efforts on hydraulic performances of landfill final cover soil , there are few studies about gas transport characteristics of landfill cover soils. Therefore, the effects of soil physical properties such as bulk density (i.e., compaction level), soil particle size and water blockage effects on the gas exchange in t highly compacted final cover soil are largely unknown. The gas exchange through the final cover soils is controlled by advective and diffusive gas transport. Air permeability (ka) governs the advective gas transport while the soil-gas diffusion coefficient (Dp) governs diffusive gas transport . In this study, the effects of compaction level and water blockage effects on ka and Dp for two landfill final cover soils were investigated. The disturbed soil samples were taken from landfill final covers in Japan and Sri Lanka. A compaction tests were performed for the soil samples with two different size fractions (< 35 mm and < 2.0 mm). In the compaction tests at field water content , the soil samples were repacked into soil cores (i.d. 15-cm, length 12-cm) at two different compaction levels (2700 kN/m2 and 600 kN/m2). After the compaction tests, ka and Dp were measured and then samples were saturated and subsequently drained at different soil-water matric potential (pF; pF equals to log(-ɛ) where ɛ is soil-water matric potential in cm H2O) of 1.5, 2.0, 3.0, 4.1, and with air-dried (pF 6.0) and oven-dried (pF 6.9) conditions. Results showed that measured Dp values

  3. Estimation of the Unsaturated Hydraulic Soil Properties From Joint Inversion of Tension Infiltrometer and ERT Measurements: Numerical Experiments

    NASA Astrophysics Data System (ADS)

    Schneider, S.; Vanderborght, J.; Kemna, A.; Pessel, M.; Coquet, Y.

    2007-12-01

    An accurate and time-efficient estimation of unsaturated hydraulic soil properties in the field remains a challenge. Tension-infiltrometry is often used to determine unsaturated hydraulic soil properties and their spatial variability in the field. Due to capillary flow, a 3-D wetting bulb, which depends on the unsaturated hydraulic soil properties, the radius of the infiltrometer disk, and the applied water tension, develops under a tension infiltrometer. Electrical resistivity tomography (ERT) offers the possibility to image the spatial distribution of bulk soil electrical conductivity, which is related through a petrophysical model to the soil water content. Therefore, ERT data contain information about the 3-D structure of the wetting bulb, which may be exploited to infer hydraulic soil properties. A combination of tension-infiltrometer and ERT data for an inverse estimation of the soil hydraulic parameters was tested in a numerical experiment. Both 3-D water flow and electrical potential fields were simulated with the SWMS_3-D model using the van Genuchten hydraulic functions and the Rhoades petrophysical model. Simulated infiltration and simulated apparent electrical resistivities were subsequently inverted using the PEST software. Inversion of the combined infiltration and ERT datasets showed that the hydraulic parameters could be inverted from a single infiltration experiment, which is not possible when only infiltration data are used in the inversion. Also petrophysical parameters could be inverted simultaneously with hydraulic parameters from the combined ERT-infiltrometer data. These results demonstrate the potential of the method by considering additional information about the structure of the wetting bulb which is contained in ERT data.

  4. Identification of descriptive parameters of gradated soils using column experiments and analysis of CT data

    NASA Astrophysics Data System (ADS)

    Binner, Richard; Homberg, Ulrike; Prohaska, Steffen; Kalbe, Ute; Berger, Wolfgang; Witt, Karl Josef

    2010-05-01

    In this contribution, we present a method that combines experimental and micro-tomographic information to derive parameters of the pore structure of gradated soils. High-resolution CT data of samples of gradated soils are acquired. Parameters such as the pore positions and the pore sizes, the pore paths, and the pore constrictions are computed by applying methods of image analysis. Further, specific parameters of the pore and soil structure are determined using column and compacting experiments based on model soils. The grain size and effluent quantity of potentially mobile particles are identified, as well as the characteristics of the supporting skeleton of the model. The results of a comparison of both methods suggest that column experiments in combination with automatic image processing methods can provide suitable geometric parameters of real grain and pore structure for analyzing suffosive erosion phenomena. This visualization allows a better understanding of the various physical processes within the pore structure. But for a qualitative approach these parameters can be incorporated into pore-network models to verify existing transport models. This research is a part of a comprehensive research project on suffosion of soils.

  5. Main Parameters of Soil Quality and it's Management Under Changing Climate

    NASA Astrophysics Data System (ADS)

    László Phd, M., ,, Dr.

    2009-04-01

    byproducts and atmospheric deposition; 4. storing and cycling nutrients and other elements within the earth's biosphere; and 5. providing support of socioeconomic structures and protection for archeological treasures associated with human habitation. No soil is likely to successfully provide all of these functions, some of which occur in natural ecosystems and some of which are the result of human modification. We can summarize by saying that soil quality depends on the extent to which soil functions to benefit humans. Thus, for food production or mediation of contamination, soil quality means the extent to which a soil fulfills the role we have defined for it. Within agriculture, high quality equates to maintenance of high productivity without significant soil or environmental degradation. The Glossary of Soil Science terms produced by the Soil Science Society of America (1996) states that soil quality is an inherent attribute of a soil that is inferred from soil characteristics or indirect observations. To proceed from a dictionary definition to a measure of soil quality, a minimum dataset (MDS) of soil characteristics that represents soil quality must be selected and quantified (Papendick et al., 1995). The MDS may include biological, chemical or physical soil characteristics [Organic matter (OM), Aggregation (A), Bulk density (BD), Depth to hardpan (DH), Electrical conductivity (EC), Fertility (F), Respiration (R), pH, Soil test (ST), Yield (Y), Infiltration (I), Mineralizable nitrogen potential (MNP), Water holding capacity (WHC)]. For agriculture, the measurement of properties should lead to a relatively simple and accurate way to rank soils based on potential plant production without soil degradation. Unfortunately, commonly identified soil quality parameters may not correlate well with yield (Reganold, 1988). In the next section, we consider these four points concerning the selection and quantification of soil characteristics: 1. soil characteristics may be desirable

  6. A GPS Backpack System for Mapping Soil and Crop Parameters in Agricultural Fields

    NASA Astrophysics Data System (ADS)

    Stafford, J. V.; Lebars, J. M.

    Farmers are having to gather increasing amounts of data on their soils and crops. Precision agriculture metre-by-metre is based on a knowledge of the spatial variation of soil and crop parameters across a field. The data has to be spatially located and GPS is an effective way of doing this. A backpack data logging system with GPS position tagging is described which has been designed to aid a fanner in the manual collection of data.

  7. Global SMOS Soil Moisture Retrievals using the Land Parameter Retrieval Model

    NASA Astrophysics Data System (ADS)

    van der Schalie, Robin; de Jeu, Richard; Kerr, Yann; Wigneron, Jean-Pierre; Rodriguez-Fernandez, Nemesio; Alyaari, Amen; Drusch, Matthias; Mecklenburg, Susanne; Dolman, Han

    2015-04-01

    The Land Parameter Retrieval Model (LPRM) is a methodology that retrieves soil moisture from low frequency dual polarized microwave measurements and has been extensively tested on C-, X- and Ku-band frequencies. Its performance on L-band is tested here by using observations from the Soil Moisture and Ocean Salinity (SMOS) satellite. These observations have potential advantages compared to higher frequencies: a low sensitivity to cloud and vegetation contamination, an increased thermal sampling depth and a greater sensitivity to soil moisture fluctuations. These features make it desirable to add SMOS-derived soil moisture retrievals to the existing European Space Agency (ESA) long-term climatological soil moisture data record, to be harmonized with other passive microwave soil moisture estimates from the LPRM. SMOS measures brightness temperature at a range of incidence angles, different incidence angles bins (42.5°, 47.5°, 52.5° and 57.5°) were combined and tested for both ascending and descending swaths. Two SMOS LPRM algorithm parameters, the single scattering albedo and roughness, were optimized against soil moisture from MERRA-Land, ERA-Interim/Land and AMSR-E LPRM over the period of July 2010 to December 2010. The SMOS LPRM soil moisture retrievals, using the optimized parameters, were then evaluated against the latest SMOS Level 3 (L3) soil moisture product and a set of in situ networks over the period of July 2010 to December 2013. The evaluation against SMOS L3 result in very high correlations over many parts of the world (>0.85), which is in line with earlier findings when SMOS LPRM was compared to SMOS L3 over the OzNet sites in southeast Australia. This study is part of an ESA project (de Jeu et al., this conference, session CL 5.7).

  8. Assessment of soil quality parameters using multivariate analysis in the Rawal Lake watershed.

    PubMed

    Firdous, Shahana; Begum, Shaheen; Yasmin, Azra

    2016-09-01

    Soil providing a wide array of ecosystem services is subjected to quality deterioration due to natural and anthropogenic factors. Most of the soils in Pakistan have poor status of available plant nutrients and cannot support optimum levels of crop productivity. The present study statistically analyzed ten soil quality parameters in five subwatersheds (Bari Imam, Chattar, Rumli, Shahdra, and Shahpur) of the Rawal Lake. Analysis of variance (ANOVA), cluster analysis (CA), and principal component analysis (PCA) were performed to evaluate correlation in soil quality parameters on spatiotemporal and vertical scales. Soil organic matter, electrical conductivity, nitrates, and sulfates were found to be lower than that required for good quality soil. Soil pH showed significant difference (p < 0.05) in mean values at different sampling sites and sampling months indicating that it is affected and determined by land uses and seasons. Pearson correlation revealed a strong positive correlation (r = 0.437) between nitrates and organic matter. Application of principal component analysis resulted in three major factors contributing 76 % of the total variance. For factor 1, temperature, sand, silt, clay, and nitrates had the highest factor loading values (>0.75) and indicated that these were the most influential parameters of first factor or component. Cluster analysis separated five sampling sites into three statistically significant clusters: I (Shahdra-Bari Imam), II (Chattar), and III (Shahpur-Rumli). Among the five sites, Shahdra was found to have good quality soil followed by Bari Imam. The present study illustrated the usefulness of multivariate statistical approaches for the analysis and interpretation of complex datasets to understand variations in soil quality for effective watershed management. PMID:27553947

  9. Modeling spatial and seasonal soil moisture in a semi arid hillslope: The impact of integrating soil surface seal parameters

    NASA Astrophysics Data System (ADS)

    Sela, Shai; Svoray, Tal; Assouline, Shmuel

    2010-05-01

    Modeling hillslope hydrology and the complex and coupled reaction of runoff processes to rainfall, lies in the focus of a growing number of research studies. The ability to characterize and understand the mechanisms underlying the complex hillslope soil moisture patterns, which trigger spatially variable non linear runoff initiation, still remains a current hydrological challenge especially in ungauged catchments. In humid climates, connectivity of transient moisture patches was suggested as a unifying concept for studying thresholds for subsurface flow and redistribution of soil moisture at the hillslope scale. In semiarid areas, however, transient moisture patches control also the differentiation between evaporation and surface runoff and the ability to identify a unifying concept controlling the large variability of soil moisture at the hillslope scale remains an open research gap. At the LTER Lehavim site in the center of Israel (31020' N, 34045' E) a typical hillslope (0.115 km2) was chosen offering different aspects and a classic geomorphologic banding. The annual rainfall is 290 mm, the soils are brown lithosols and arid brown loess and the dominant rock formations are Eocenean limestone and chalk with patches of calcrete. The vegetation is characterised by scattered dwarf shrubs (dominant species Sarcopoterium spinosum) and patches of herbaceous vegetation, mostly annuals, are spread between rocks and dwarf shrubs. An extensive spatial database of soil hydraulic and environmental parameters (e.g. slope, radiation, bulk density) was measured in the field and interpolated to continuous maps using geostatistical techniques and physically based modelling. To explore the effect of soil surface sealing, Mualem and Assouline (1989) equations describing the change in hydraulic parameters resulting from soil seal formation were applied. Two simple indices were developed to describe local evaporation values and contribution of water from rock outcrops to the soil

  10. Impact of pesticides on soil microbiological parameters and possible bioremediation strategies.

    PubMed

    Chowdhury, Ashim; Pradhan, Saswati; Saha, Monidipta; Sanyal, Nilanjan

    2008-03-01

    Intensive agriculture is spectacularly successful since last couple of decades due to the inputs viz; fertilizers and pesticides along with high yielding varieties. The mandate for agriculture development was to feed and adequate nutrition supply to the expanding population by side the agriculture would be entering to into new area of commercial and export orientation. The attention of public health and proper utilization natural resources are also the main issues related with agriculture development. Concern for pesticide contamination in the environment in the current context of pesticide use has assumed great importance [1]. The fate of the pesticides in the soil environment in respect of pest control efficacy, non-target organism exposure and offsite mobility has been given due consideration [2]. Kinetics and pathways of degradation depend on abiotic and biotic factors [6], which are specific to a particular pesticide and therefore find preference. Adverse effect of pesticidal chemicals on soil microorganisms [3], may affect soil fertility [4] becomes a foreign chemicals major issue. Soil microorganisms show an early warning about soil disturbances by foreign chemicals than any other parameters.But the fate and behavior of these chemicals in soil ecosystem is very important since they are degraded by various factors and have the potential to be in the soil, water etc. So it is indispensable to monitor the persistence, degradation of pesticides in soil and is also necessary to study the effect of pesticide on the soil quality or soil health by in depth studies on soil microbial activity.The removal of metabolites or degraded products should be removed from soil and it has now a day's primary concern to the environmentalist. Toxicity or the contamination of pesticides can be reduced by the bioremediation process which involves the uses of microbes or plants. Either they degrade or use the pesticides by various co metabolic processes. PMID:23100705

  11. Quantification of parameters controlling the carbon stocks in German agricultural soils

    NASA Astrophysics Data System (ADS)

    Vos, Cora; Don, Axel; Freibauer, Annette; Heidkamp, Arne; Prietz, Roland

    2016-04-01

    Within the framework of UNFCCC, Germany is obligated to report on its greenhouse gas emissions from soils. This also includes the emissions in the agricultural sector. Changes in soil carbon stocks are a major source of CO2 that need to be reported. Until now there are only regional inventories of the soil carbon stocks in the agricultural sector while for the forestry sector a repeated national inventory exists. In order to report on changes in soil carbon stocks in agricultural soils, a consistent, representative and quantitative dataset of agricultural soil properties, especially on carbon stocks and management data is necessary. In the course of the German Agricultural Soil Inventory 3109 agricultural sites are examined. Up to January 2016, 2450 sites were sampled. The sites are sampled in five depth increments and all samples are analyzed in the same laboratory. Of the sampled sites the laboratory analyses are completed for 1312 sites. The samples of all depth increments were analyzed for their texture, bulk density, pH, electric conductivity, stone and root content, organic and inorganic carbon content and nitrogen content. The data are coupled with management data covering the past ten years and with climate data. They are analyzed with multivariate statistical techniques (e.g. mixed effects models, additive models, random forest) to quantify the parameters that control the carbon stocks in German agricultural soils. First descriptive results show that the mean soil carbon stocks down to a depth of 100 cm are 126.1 t ha-1 (range 8.9-1158.9 t ha-1). The mean stocks only for croplands are 102.6 t ha-1 (range 8.9-1158.9 t ha-1), while for grasslands the mean stock is 184.1 t ha-1 (range 19.4-937.8 t ha-1). In total the soil scientists found a surprisingly high proportion of disturbed and unusual soil profiles, indicating intensive human modifications of agricultural soils through e.g. deep ploughing. The data set of the German Agricultural Soil Inventory is the

  12. Quantification of parameters controlling the carbon stocks in German agricultural soils

    NASA Astrophysics Data System (ADS)

    Vos, Cora; Don, Axel; Freibauer, Annette; Heidkamp, Arne; Prietz, Roland

    2016-04-01

    Within the framework of UNFCCC, Germany is obligated to report on its greenhouse gas emissions from soils. This also includes the emissions in the agricultural sector. Changes in soil carbon stocks are a major source of CO2 that need to be reported. Until now there are only regional inventories of the soil carbon stocks in the agricultural sector while for the forestry sector a repeated national inventory exists. In order to report on changes in soil carbon stocks in agricultural soils, a consistent, representative and quantitative dataset of agricultural soil properties, especially on carbon stocks and management data is necessary. In the course of the German Agricultural Soil Inventory 3109 agricultural sites are examined. Up to January 2016, 2450 sites were sampled. The sites are sampled in five depth increments and all samples are analyzed in the same laboratory. Of the sampled sites the laboratory analyses are completed for 1312 sites. The samples of all depth increments were analyzed for their texture, bulk density, pH, electric conductivity, stone and root content, organic and inorganic carbon content and nitrogen content. The data are coupled with management data covering the past ten years and with climate data. They are analyzed with multivariate statistical techniques (e.g. mixed effects models, additive models, random forest) to quantify the parameters that control the carbon stocks in German agricultural soils. First descriptive results show that the mean soil carbon stocks down to a depth of 100 cm are 126.1 t ha‑1 (range 8.9-1158.9 t ha‑1). The mean stocks only for croplands are 102.6 t ha‑1 (range 8.9-1158.9 t ha‑1), while for grasslands the mean stock is 184.1 t ha‑1 (range 19.4-937.8 t ha‑1). In total the soil scientists found a surprisingly high proportion of disturbed and unusual soil profiles, indicating intensive human modifications of agricultural soils through e.g. deep ploughing. The data set of the German Agricultural Soil

  13. Nonlinear soil parameter effects on dynamic embedment of offshore pipeline on soft clay

    NASA Astrophysics Data System (ADS)

    Yu, Su Young; Choi, Han Suk; Lee, Seung Keon; Park, Kyu-Sik; Kim, Do Kyun

    2015-06-01

    In this paper, the effects of nonlinear soft clay on dynamic embedment of offshore pipeline were investigated. Seabed embedment by pipe-soil interactions has impacts on the structural boundary conditions for various subsea structures such as pipeline, riser, pile, and many other systems. A number of studies have been performed to estimate real soil behavior, but their estimation of seabed embedment has not been fully identified and there are still many uncertainties. In this regards, comparison of embedment between field survey and existing empirical models has been performed to identify uncertainties and investigate the effect of nonlinear soil parameter on dynamic embedment. From the comparison, it is found that the dynamic embedment with installation effects based on nonlinear soil model have an influence on seabed embedment. Therefore, the pipe embedment under dynamic condition by nonlinear parameters of soil models was investigated by Dynamic Embedment Factor (DEF) concept, which is defined as the ratio of the dynamic and static embedment of pipeline, in order to overcome the gap between field embedment and currently used empirical and numerical formula. Although DEF through various researches is suggested, its range is too wide and it does not consider dynamic laying effect. It is difficult to find critical parameters that are affecting to the embedment result. Therefore, the study on dynamic embedment factor by soft clay parameters of nonlinear soil model was conducted and the sensitivity analyses about parameters of nonlinear soil model were performed as well. The tendency on dynamic embedment factor was found by conducting numerical analyses using OrcaFlex software. It is found that DEF was influenced by shear strength gradient than other factors. The obtained results will be useful to understand the pipe embedment on soft clay seabed for applying offshore pipeline designs such as on-bottom stability and free span analyses.

  14. Employing satellite retrieved soil moisture for parameter estimation of the hydrologic model mHM

    NASA Astrophysics Data System (ADS)

    Zink, Matthias; Mai, Juliane; Rakovec, Oldrich; Schrön, Martin; Kumar, Rohini; Schäfer, David; Samaniego, Luis

    2016-04-01

    Hydrological models are usually calibrated against observed streamflow at the catchment outlet and thus they are conditioned by an integral catchment signal. Rakovec et al. 2016 (JHM) recently demonstrated that constraining model parameters against river discharge is a necessary, but not a sufficient condition. Such a procedure ensures the fulfillment of the catchment's water balance but can lead to high predictive uncertainties of model internal states, like soil moisture, or a lack in spatial representativeness of the model. However, some hydrologic applications, as e.g. soil drought monitoring and prediction, rely on this information. Within this study we propose a framework in which the mesoscale Hydrologic Model (mHM) is calibrated with soil moisture retrievals from various sources. The aim is to condition the model on soil moisture (SM), while preserving good performance in streamflow estimation. We identify the most appropriate objective functions by conducting synthetic experiments. The best objective function is determined based on: 1) deviation between synthetic and simulated soil moisture, 2) nonparametric comparison of SM fields (e.g. copulas), and 3) by euclidian distance of model parameters, which is zero if the parameters of the synthetic data are recovered. Those objective functions performing best are used to calibrate mHM against different satellite soil moisture products, e.g. ESA-CCI, H-SAF, and in situ observations. This procedure is tested in three distinct European basins (upper Sava, Neckar, and upper Guadalquivir basin) ranging from snow domination to semi arid climatic conditions. Results obtained with the synthetic experiment indicate that objective functions focusing on the temporal dynamics of SM are preferable to objective functions aiming at spatial patterns or catchment averages. Since the deviation of soil moisture fields (1) and their copulas (2) don't lead to conclusive results, the decision of the best performing objective

  15. Cadmium toxicity for terrestrial invertebrates: taking soil parameters affecting bioavailability into account.

    PubMed

    Lock, K; Janssen, C R

    2001-10-01

    Acute and chronic ecotoxicity tests with cadmium were conducted with the earthworm Eisenia fetida, the potworm Enchytraeus albidus and the springtail Folsomia candida. To assess the influence of the soil type on cadmium bioavailability, these tests were carried out in a standard artificial soil, in a sandy and a loamy field soil. It was not possible to evaluate the influence of soil parameters on the bioavailability on the basis of the experiments that were conducted in only three different soil types, therefore, literature data were also included. However, even in the same standard artificial soils, toxicity data in the literature for Eisenia fetida and Folsomia candida varied considerably. Consequently, no models could be developed that allow a normalization of the ecotoxicity of cadmium to parameters controlling bioavailability. In contrast to zinc, effect concentrations of cadmium for terrestrial invertebrates were always much higher than background concentrations. As the effect of aging on the bioavailability of cadmium was never taken into account, because toxicity experiments were always carried out in freshly spiked soilds, these effect concentrations may even be regarded as conservative. Furthermore, the zinc-cadmium ratio in soils is usually so high that the risk of zinc ecotoxicity for terrestrial invertebrates will usually be much greater in comparison to cadmium ecotoxicity. PMID:11556119

  16. Cadmium toxicity for terrestrial invertebrates: taking soil parameters affecting bioavailability into account.

    PubMed

    Lock, K; Janssen, C R

    2001-10-01

    Acute and chronic ecotoxicity tests with cadmium were conducted with the earthworm Eisenia fetida, the potworm Enchytraeus albidus and the springtail Folsomia candida. To assess the influence of the soil type on cadmium bioavailability, these tests were carried out in a standard artificial soil, in a sandy and a loamy field soil. It was not possible to evaluate the influence of soil parameters on the bioavailability on the basis of the experiments that were conducted in only three different soil types, therefore, literature data were also included. However, even in the same standard artificial soils, toxicity data in the literature for Eisenia fetida and Folsomia candida varied considerably. Consequently, no models could be developed that allow a normalization of the ecotoxicity of cadmium to parameters controlling bioavailability. In contrast to zinc, effect concentrations of cadmium for terrestrial invertebrates were always much higher than background concentrations. As the effect of aging on the bioavailability of cadmium was never taken into account, because toxicity experiments were always carried out in freshly spiked soilds, these effect concentrations may even be regarded as conservative. Furthermore, the zinc-cadmium ratio in soils is usually so high that the risk of zinc ecotoxicity for terrestrial invertebrates will usually be much greater in comparison to cadmium ecotoxicity.

  17. Georeferenced database on soil and air climate parameters of Russia and its cartographic implications

    NASA Astrophysics Data System (ADS)

    Alyabina, Irina; Reshotkin, Oleg; Konyushkov, Dmitry; Khudyakov, Oleg

    2014-05-01

    Many theoretical and applied problems related to the assessment of ecosystem response to climate changes imply simultaneous analysis of data on air and soil climate. In particular, soil temperature is a very important characteristic allowing us to judge sensitivity of ecosystems to climatic fluctuations and anthropogenic impacts. It is also of great importance for predicting the functioning of terrestrial biocenoses, geocryological and engineering conditions of the territory, etc. The vast territory of Russia is characterized by the great diversity of soil climatic conditions and by differently directed tendencies of their recent changes. A combined study of the spatial and temporal changes in the parameters of soil and atmospheric climates of Russia and their cartographic modeling are of great interest. Russia has a well-developed network of weather stations, at which measurements of soil temperatures at standard depths have been performed using the same methods for more than a century. The analysis of these data with the use of geographic information systems seems to be promising. For this purpose, a georeferenced database on the parameters of soil and atmospheric climate is being developed. Such a database in the GIS environment makes it possible to develop a system of cartographic models of the climate of Russian soils, including data on the climatic norm (1960-1990) and on its changes in the recent decades. This system will be used for assessing soil climatic conditions in the subjects of the Russian Federation and in separate soil-geographic provinces. A series of small-scale preliminary maps of soil temperature parameters was included in the National Soil Atlas of the Russian Federation (2011). These maps indicate that the mean annual soil temperature in Russia varies from -14.5 to +15.2ºC, and the accumulated daily temperatures >10ºC increase in the southward direction from 0 to 4800ºC (degree-days). The duration of the period with soil temperatures >10

  18. Methane oxidation in three Alberta soils: influence of soil parameters and methane flux rates.

    PubMed

    Stein, V B; Hettiaratchi, J P

    2001-01-01

    Current concern over the potentially negative impacts of climate change has brought attention to anthropogenic sources of methane, a primary greenhouse gas. Two such emission sources are methane leakage at heavy oil wells and sanitary landfills. At both of these sources, substantial quantities of methane could potentially be oxidised by methanotrophic microbes living in soils. Optimisation of this phenomenon may serve as an inexpensive technique for reducing methane emissions. Soil column and batch incubation experiments were performed on a landfill loam, an agricultural loam and a sedge peat to gain a better quantitative understanding of the biological and physical processes limiting CH4 oxidation in soils that undergo the freeze-thaw cycles associated with northern climates. Moisture content emerged as a critical variable that can limit a soil's CH4 oxidation potential. For example, the oxidation rate of the agricultural soil was seen to increase by an order of magnitude after increasing its moisture content from 6% to 10% of its dry weight.

  19. Discrimination of soils and assessment of some soil fertility parameters using an electronic tongue

    NASA Astrophysics Data System (ADS)

    Mimendia, Aitor; Gutiérrez, Juan Manuel; Alcañiz, Josep Maria; del Valle, Manel

    2011-09-01

    In this communication, a new strategy to perform soil classification and/or characterization is reported, which is the coupling of chemical sensors with a pattern recognition method, what is known as an electronic tongue. Following this approach, the system proposed in this paper uses a sensor array formed by potentiometric sensors with generic cross response against several cations and anions, plus a pattern recognition method based on Artificial Neural Networks (ANNs); the sensor-based system allows performing a simple laboratory procedure where the advanced data processing methodology permits to extract the meaningful information. In this way this work represents the first application and testing of an electronic tongue in soil analysis. Apart from the qualitative classification application, a quantitative analysis of certain chemical features related to soil fertility has also been attempted.

  20. Vertisols with Gilgai Microtopography: Classification and Parameters of Microtopography and Morphological Types of Soils (a Review)

    NASA Astrophysics Data System (ADS)

    Khitrov, N. B.

    2016-02-01

    Data on clayey swelling soils with gilgai microtopography are systematized. Classifications of gilgai microtopography representing regularly alternating microhighs and microlows are discussed, and its geometric parameters under different landscape conditions are considered. Gilgai microtopography is developed within flat or slightly inclined elements of the mesorelief composed of swelling clays of different geneses. These materials are characterized by the high swelling-shrinking capacity upon wetting-drying cycles owing to the predominance of clay minerals of smectitic group. These processes are especially pronounced under conditions of the impeded surface drainage and contrasting of the wet seasons with strong soil moistening by atmospheric precipitation or surface water and the seasons with deep soil drying under the impact of physical evaporation and transpiration. The areas with gilgai microtopography have complex soil cover patterns composed of Vertisols and vertic soils. Their formation is related to lateral movements of solid material in the soil profiles and along the curved soil surface. The morphological types of soil complexes in such area are systematized.

  1. The influence of selecting the correlation model on soil parameters and bearing capacity

    NASA Astrophysics Data System (ADS)

    Pieczynska-Kozlowska, Joanna M.

    2016-04-01

    Consideration of soil spatial variability in the geotechnical design is still marginalized. The design process is based on taking the average parameters, which often results the oversize of geotechnical constructions. This procedure works until there are no geotechnical design problems. In most cases, geotechnical constructions represent a small percentage of the total investment so effects lacking developed of optimization procedures. If the optimization is needed requires the most accurate mapping of the soil. The basic background for statistical interpretation of soil spatially variables are Cone Penetration Tests, which represents variable nature of the soil with depth. Assuming the soil structure as a spatially random variable can be applied by description based on random fields. Field parameters are the probability distribution and correlation model dependent of a scale of fluctuation estimated from CPT. The main goal of this study is to contribute to the understanding on how the choice of correlation model affects random soil properties and for example shallow foundation bearing capacity. The study is particularly focused on scale of fluctuation as related to the reduction of bearing capacity. Scale of fluctuation were estimated using two effective methods: Vanmarcke and Rice. Soil properties were analyzed from 12 Cone Penetration Tests distributed throughout the regions of Świebodzice (Lower Silesia, Poland). While the project was developed in hilly terrain the macrolevelling were taken involving the displacement of native soil mass to form a working platform for shallow foundation. The construction of embankment has been tested by cone resistance tests to determine the parameters for the design. The procedure adopted to this study include the modeling soil variability from the CPT results and calculate the bearing capacity of shallow foundation using random finite element method and different correlation models. The aim of study was to answer questions

  2. Microbial models with data-driven parameters predict stronger soil carbon responses to climate change.

    PubMed

    Hararuk, Oleksandra; Smith, Matthew J; Luo, Yiqi

    2015-06-01

    Long-term carbon (C) cycle feedbacks to climate depend on the future dynamics of soil organic carbon (SOC). Current models show low predictive accuracy at simulating contemporary SOC pools, which can be improved through parameter estimation. However, major uncertainty remains in global soil responses to climate change, particularly uncertainty in how the activity of soil microbial communities will respond. To date, the role of microbes in SOC dynamics has been implicitly described by decay rate constants in most conventional global carbon cycle models. Explicitly including microbial biomass dynamics into C cycle model formulations has shown potential to improve model predictive performance when assessed against global SOC databases. This study aimed to data-constrained parameters of two soil microbial models, evaluate the improvements in performance of those calibrated models in predicting contemporary carbon stocks, and compare the SOC responses to climate change and their uncertainties between microbial and conventional models. Microbial models with calibrated parameters explained 51% of variability in the observed total SOC, whereas a calibrated conventional model explained 41%. The microbial models, when forced with climate and soil carbon input predictions from the 5th Coupled Model Intercomparison Project (CMIP5), produced stronger soil C responses to 95 years of climate change than any of the 11 CMIP5 models. The calibrated microbial models predicted between 8% (2-pool model) and 11% (4-pool model) soil C losses compared with CMIP5 model projections which ranged from a 7% loss to a 22.6% gain. Lastly, we observed unrealistic oscillatory SOC dynamics in the 2-pool microbial model. The 4-pool model also produced oscillations, but they were less prominent and could be avoided, depending on the parameter values.

  3. Sensitivity of soil water content simulation to different methods of soil hydraulic parameter characterization as initial input values

    NASA Astrophysics Data System (ADS)

    Rezaei, Meisam; Seuntjens, Piet; Shahidi, Reihaneh; Joris, Ingeborg; Boënne, Wesley; Cornelis, Wim

    2016-04-01

    Soil hydraulic parameters, which can be derived from in situ and/or laboratory experiments, are key input parameters for modeling water flow in the vadose zone. In this study, we measured soil hydraulic properties with typical laboratory measurements and field tension infiltration experiments using Wooding's analytical solution and inverse optimization along the vertical direction within two typical podzol profiles with sand texture in a potato field. The objective was to identify proper sets of hydraulic parameters and to evaluate their relevance on hydrological model performance for irrigation management purposes. Tension disc infiltration experiments were carried out at five different depths for both profiles at consecutive negative pressure heads of 12, 6, 3 and 0.1 cm. At the same locations and depths undisturbed samples were taken to determine the water retention curve with hanging water column and pressure extractors and lab saturated hydraulic conductivity with the constant head method. Both approaches allowed to determine the Mualem-van Genuchten (MVG) hydraulic parameters (residual water content θr, saturated water content θs,, shape parameters α and n, and field or lab saturated hydraulic conductivity Kfs and Kls). Results demonstrated horizontal differences and vertical variability of hydraulic properties. Inverse optimization resulted in excellent matches between observed and fitted infiltration rates in combination with final water content at the end of the experiment, θf, using Hydrus 2D/3D. It also resulted in close correspondence of  and Kfs with those from Logsdon and Jaynes' (1993) solution of Wooding's equation. The MVG parameters Kfs and α estimated from the inverse solution (θr set to zero), were relatively similar to values from Wooding's solution which were used as initial value and the estimated θs corresponded to (effective) field saturated water content θf. We found the Gardner parameter αG to be related to the optimized van

  4. Identifying mechanical property parameters of planetary soil using in-situ data obtained from exploration rovers

    NASA Astrophysics Data System (ADS)

    Ding, Liang; Gao, Haibo; Liu, Zhen; Deng, Zongquan; Liu, Guangjun

    2015-12-01

    Identifying the mechanical property parameters of planetary soil based on terramechanics models using in-situ data obtained from autonomous planetary exploration rovers is both an important scientific goal and essential for control strategy optimization and high-fidelity simulations of rovers. However, identifying all the terrain parameters is a challenging task because of the nonlinear and coupling nature of the involved functions. Three parameter identification methods are presented in this paper to serve different purposes based on an improved terramechanics model that takes into account the effects of slip, wheel lugs, etc. Parameter sensitivity and coupling of the equations are analyzed, and the parameters are grouped according to their sensitivity to the normal force, resistance moment and drawbar pull. An iterative identification method using the original integral model is developed first. In order to realize real-time identification, the model is then simplified by linearizing the normal and shearing stresses to derive decoupled closed-form analytical equations. Each equation contains one or two groups of soil parameters, making step-by-step identification of all the unknowns feasible. Experiments were performed using six different types of single-wheels as well as a four-wheeled rover moving on planetary soil simulant. All the unknown model parameters were identified using the measured data and compared with the values obtained by conventional experiments. It is verified that the proposed iterative identification method provides improved accuracy, making it suitable for scientific studies of soil properties, whereas the step-by-step identification methods based on simplified models require less calculation time, making them more suitable for real-time applications. The models have less than 10% margin of error comparing with the measured results when predicting the interaction forces and moments using the corresponding identified parameters.

  5. Soil water content and evaporation determined by thermal parameters obtained from ground-based and remote measurements

    NASA Technical Reports Server (NTRS)

    Reginato, R. J.; Idso, S. B.; Jackson, R. D.; Vedder, J. F.; Blanchard, M. B.; Goettelman, R.

    1976-01-01

    Soil water contents from both smooth and rough bare soil were estimated from remotely sensed surface soil and air temperatures. An inverse relationship between two thermal parameters and gravimetric soil water content was found for Avondale loam when its water content was between air-dry and field capacity. These parameters, daily maximum minus minimum surface soil temperature and daily maximum soil minus air temperature, appear to describe the relationship reasonably well. These two parameters also describe relative soil water evaporation (actual/potential). Surface soil temperatures showed good agreement among three measurement techniques: in situ thermocouples, a ground-based infrared radiation thermometer, and the thermal infrared band of an airborne multispectral scanner.

  6. Multi-method geophysical measurements for soil science investigations in the vadose zone

    NASA Astrophysics Data System (ADS)

    Weihnacht, B.; Börner, F.

    2007-08-01

    We studied the changes of geophysical parameters on a soil wall of the testfield Grenzhof (University of Heidelberg). The unsaturated materials investigated range from coarse-grain gravel to sandy loam. Ground-penetrating radar, ultrasound transmission and complex conductivity measurements were applied as geophysical methods. The measured parameters were used to calculate soil parameters such as porosity, water content, density and grain surface area necessary to obtain geohydraulic parameters such as hydraulic conductivity, field capacity and retention parameters. Soil samples were taken and analysed regarding porosity, apparent density, true density and internal surface. The comparison between petrophysical data from the laboratory and from geophysical measurements showed good correlations for the majority of the data.

  7. Estimating unique soil hydraulic parameters for sandy media from multi-step outflow experiments

    NASA Astrophysics Data System (ADS)

    Il Hwang, Sang; Powers, Susan E.

    Estimating unique soil hydraulic parameters is required to provide input for numerical models simulating transient water flow in the vadose zone. In this paper, we analyze the capability of six soil hydraulic functions to provide unique parameter sets for sandy soils from multi-step outflow data. Initial parameter estimates and experimental boundary conditions were explored to determine their affect on the uniqueness of soil hydraulic functions. Of the hydraulic functions tested, the lognormal distribution-Mualem (LDM) function provided the best performance and a unique solution for error-free numerically generated multi-step outflow data. For experimental multi-step outflow data with inherent measurement errors, the LDM function again showed better performance and uniqueness than the van Genuchten-Mualem and Gardner-Mualem functions. In experiments with different boundary conditions, the LDM function provided the best fitting ability, resulting in unique parameter sets when the intrinsic permeability ( k) was fixed at its measured value. The experiment that had a greater number of pneumatic pressure steps, thereby causing a lower flow rate, provided better fitting ability and more unique solutions than faster experiments.

  8. No-Till Management Effects on Soil Water and Wind Erodibility Parameters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The extent to which no-till management improves water and wind erodibility parameters is not well understood. This study assessed changes in aggregate resistance to raindrops, dry aggregate wettability, and dry aggregate stability as well as their relationships with changes in soil organic carbon co...

  9. Thermal analysis to derive energetic quality parameters of soil organic matter?

    NASA Astrophysics Data System (ADS)

    Peikert, Benjamin; Schaumann, Gabriele Ellen

    2014-05-01

    Many studies have dealt with thermal analysis for characterisation of soil and soil organic matter. It is a versatile tool assessing various physicochemical properties of the sample during heating and/or cooling. Especially the combination of different detection methods is highly promising. In this contribution, we will discuss the combination of thermogravimetry (TGA) with differential scanning calorimetry (DSC) in one single thermal analysis device. TGA alone helps distinguishment of soil and soil organic matter fractions with respect to their resistance towards combustion and allows a quantitative assignment of thermolabile and recalcitrant OM fractions. Combination with DSC in the same device, allows determination of energy transformation during the combustion process. Therefore, it becomes possible to determine not only the calorific value of the organic matter, but also of its fractions. We will show the potential of using the calorific values of OM fractions as quality parameter - exemplified for the analysis of soils polluted with organic matter from the olive oil production. The pollution history of these samples is largely unknown. As expected, TGA indicated a relative enrichment of the labile carbon fraction in contaminated samples with respect to the controls. The calorific values of the thermolabile and the recalcitrant fractions differ from each other, and those of the recalcitrant fractions of the polluted samples were higher than of those of the unpolluted controls. Further analyses showed correlation of the calorific value of this fraction with soil water repellency and the carbon isotopic ratio. The synthesis of our current data suggests that the content of thermolabile fraction, the isotopic ratio and calorific value of the recalcitrant fraction are useful indicators for characterizing the degree of decomposition of OMW organic matter. In this contribution, we will further discuss the potential of using the energetic parameters a quality

  10. Parameters of microbial respiration in soils of the impact zone of a mineral fertilizer factory

    NASA Astrophysics Data System (ADS)

    Zhukova, A. D.; Khomyakov, D. M.

    2015-08-01

    The carbon content in the microbial biomass and the microbial production of CO2 (the biological component of soil respiration) were determined in the upper layer (0-10 cm) of soils in the impact zone of the OJSC Voskresensk Mineral Fertilizers, one of the largest factories manufacturing mineral fertilizers in Russia. Statistical characteristics and schematic distribution of the biological parameters in the soil cover of the impact zone were analyzed. The degree of disturbance of microbial communities in the studied objects varied from weak to medium. The maximum value (0.44) was observed on the sampling plot 4 km away from the factory and 0.5 km away from the place of waste (phosphogypsum) storage. Significantly lower carbon content in the microbial biomass and its specific respiration were recorded in the agrosoddy-podzolic soil as compared with the alluvial soil sampled at the same distance from the plant. The effects of potential soil pollutants (fluorine, sulfur, cadmium, and stable strontium) on the characteristics of soil microbial communities were described with reliable regression equations.

  11. Temperature and volumetric water content petrophysical relationships in municipal solid waste for the interpretation of bulk electrical resistivity data

    NASA Astrophysics Data System (ADS)

    Pilawski, Tamara; Dumont, Gaël; Nguyen, Frédéric

    2015-04-01

    Landfills pose major environmental issues including long-term methane emissions, and local pollution of soil and aquifers but can also be seen as potential energy resources and mining opportunities. Water content in landfills determine whether solid fractions can be separated and recycled, and controls the existence and efficiency of natural or enhanced biodegradation. Geophysical techniques, such as electrical and electromagnetic methods have proven successful in the detection and qualitative investigation of sanitary landfills. However, their interpretation in terms of quantitative water content estimates makes it more challenging due to the influence of parameters such as temperature, compaction, waste composition or pore fluid. To improve the confidence given to bulk electrical resistivity data and to their interpretation, we established temperature and volumetric water content petrophysical relationships that we tested on field and laboratory electrical resistivity measurements. We carried out two laboratory experiments on leachates and waste samples from a landfill located in Mont-Saint-Guibert, Belgium. We determined a first relationship between temperature and electrical resistivity with pure and diluted leachates by progressively increasing the temperature from 5°C to 65°C, and then cooling down to 5°C. The second relationship was obtained by measuring electrical resistivity on waste samples of different volumetric water contents. First, we used the correlations obtained from the experiments to compare electrical resistivity measurements performed in a landfill borehole and on reworked waste samples excavated at different depths. Electrical resistivities were measured every 20cm with an electromagnetic logging device (EM39) while a temperature profile was acquired with optic fibres. Waste samples were excavated every 2m in the same borehole. We filled experimental columns with these samples and measured electrical resistivities at laboratory temperature

  12. Inverse estimation of parameters for multidomain flow models in soil columns with different macropore densities.

    PubMed

    Arora, Bhavna; Mohanty, Binayak P; McGuire, Jennifer T

    2011-04-01

    Soil and crop management practices have been found to modify soil structure and alter macropore densities. An ability to accurately determine soil hydraulic parameters and their variation with changes in macropore density is crucial for assessing potential contamination from agricultural chemicals. This study investigates the consequences of using consistent matrix and macropore parameters in simulating preferential flow and bromide transport in soil columns with different macropore densities (no macropore, single macropore, and multiple macropores). As used herein, the term"macropore density" is intended to refer to the number of macropores per unit area. A comparison between continuum-scale models including single-porosity model (SPM), mobile-immobile model (MIM), and dual-permeability model (DPM) that employed these parameters is also conducted. Domain-specific parameters are obtained from inverse modeling of homogeneous (no macropore) and central macropore columns in a deterministic framework and are validated using forward modeling of both low-density (3 macropores) and high-density (19 macropores) multiple-macropore columns. Results indicate that these inversely modeled parameters are successful in describing preferential flow but not tracer transport in both multiple-macropore columns. We believe that lateral exchange between matrix and macropore domains needs better accounting to efficiently simulate preferential transport in the case of dense, closely spaced macropores. Increasing model complexity from SPM to MIM to DPM also improved predictions of preferential flow in the multiple-macropore columns but not in the single-macropore column. This suggests that the use of a more complex model with resolved domain-specific parameters is recommended with an increase in macropore density to generate forecasts with higher accuracy. PMID:24511165

  13. Inverse estimation of parameters for multidomain flow models in soil columns with different macropore densities

    PubMed Central

    Arora, Bhavna; Mohanty, Binayak P.; McGuire, Jennifer T.

    2013-01-01

    Soil and crop management practices have been found to modify soil structure and alter macropore densities. An ability to accurately determine soil hydraulic parameters and their variation with changes in macropore density is crucial for assessing potential contamination from agricultural chemicals. This study investigates the consequences of using consistent matrix and macropore parameters in simulating preferential flow and bromide transport in soil columns with different macropore densities (no macropore, single macropore, and multiple macropores). As used herein, the term“macropore density” is intended to refer to the number of macropores per unit area. A comparison between continuum-scale models including single-porosity model (SPM), mobile-immobile model (MIM), and dual-permeability model (DPM) that employed these parameters is also conducted. Domain-specific parameters are obtained from inverse modeling of homogeneous (no macropore) and central macropore columns in a deterministic framework and are validated using forward modeling of both low-density (3 macropores) and high-density (19 macropores) multiple-macropore columns. Results indicate that these inversely modeled parameters are successful in describing preferential flow but not tracer transport in both multiple-macropore columns. We believe that lateral exchange between matrix and macropore domains needs better accounting to efficiently simulate preferential transport in the case of dense, closely spaced macropores. Increasing model complexity from SPM to MIM to DPM also improved predictions of preferential flow in the multiple-macropore columns but not in the single-macropore column. This suggests that the use of a more complex model with resolved domain-specific parameters is recommended with an increase in macropore density to generate forecasts with higher accuracy. PMID:24511165

  14. Scaling Parameters of the Lewis-Kostiakov Water Infiltration Equation Across Soil Textural Classes and Extension to Rain Infiltration

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A recent study showed that the Brooks-Corey equation parameters for soil hydraulic properties were strongly correlated to the pore-size distribution index (lambda), the slope of the log-log soil moisture characteristic curve across eleven soil textural classes from sand to clay. It further showed th...

  15. Effects of Petrophysical Anisotropy on Fault Stability in Porous Sandstones

    NASA Astrophysics Data System (ADS)

    Farrell, N. J.; Healy, D.

    2012-12-01

    To examine the relationship of porosity and permeability to fluid flow and understand fault mechanical behaviour in the subsurface, petrophysical and geometrical analyses have been conducted on samples collected from a surface fault zone outcrop. Based on quantitative field, laboratory and digital image data we can begin to understand and predict the behaviour of fluids during and after faulting and infer the impact of petrophysical patterns on rock mechanics. Previous research has shown that changes in pore pressure, associated with fluid flow, can induce changes in the stresses acting on the rock (Teufel et al., 1991). In addition to this, theoretical work suggests that depending on the orientation of anisotropic pore long axes with respect to the principal stresses, anisotropy of porosity may either increase or decrease the stability of the faulted rock (Chen & Nur, 1992; Healy, 2009). Porous sandstones sampled around a normal fault zone show anisotropy of petrophysical properties in three orientations; (x; perpendicular to the fault plane, y; down dip to the fault and z; parallel to the fault plane) with respect to the fault plane (independent of sedimentary fabric permeability) related to microfracture type and distribution and variations in pore geometry. Permeability data collected using a Jones permeameter from over seventy oriented core plugs show overall preferential fluid flow (Kmax) down dip to the fault plane while porosity values measured using a Helium porosimeter are comparatively isotropic. Image analysis from forty corresponding thin sections shows variable porosities between orthogonally oriented sections with samples close to the fault slip surface showing higher porosity in an equivalent orientation to Kmax. Interestingly with distance away from the fault slip surface, image analysis porosities are higher perpendicular to the fault plane compared to down fault dip, in contrast to Kmax orientation. Further investigations using

  16. Role and development of soil parameters for seismic responses of buried lifelines

    SciTech Connect

    Wang, L.R.L.

    1983-01-01

    Buried lifelines, e.g. oil, gas, water and sewer pipelines have been damaged heavily in recent earthquakes such as 1971 San Fernando Earthquake, in U.S.A., 1976 Tangshan Earthquake, in China, and 1978 MiyagiKen-Oki Earthquake, in Japan, among others. Researchers on the seismic performance of these buried lifelines have been initiated in the United States and many other countries. Various analytical models have been proposed. However, only limited experimental investigations are available. The sources of earthquake damage to buried lifelines include landslide, tectonic uplift-subsidence, soil liquefaction, fault displacement and ground shaking (effects of wave propagation). This paper is concerned with the behavior of buried lifeline systems subjected to surface faulting and ground shaking. The role and development of soil parameters that significantly influence the seismic responses are discussed. The scope of this paper is to examine analytically the influence of various soil and soilstructure interaction parameters to the seismic responses of buried pipelines, to report the currently available physical data of these and related parameters for immediate applications, and to describe the experiments to obtain additional information on soil resistant characteristics to longitudinal pipe motions.

  17. Variation in available cesium concentration with parameters during temperature induced extraction of cesium from soil.

    PubMed

    Parajuli, Durga; Takahashi, Akira; Tanaka, Hisashi; Sato, Mutsuto; Fukuda, Shigeharu; Kamimura, Ryuichi; Kawamoto, Tohru

    2015-02-01

    Cesium extraction behavior of brown forest type soil collected from paddy fields in Fukushima nuclear accident affected areas was studied. In nitric acid or sulfuric acid solutions at elevated temperature, the concentration of Cs in soil available for extraction, m0, has been estimated on the basis of modified canonical equation and the equations derived from assumed equilibria. With the variation in temperature, mixing time, and soil to solvent ratio, the observed m0 values in 0.5 M acid solution ranged between 1.5 and 2.9 mg cesium per kilogram of soil. By increasing the acid concentration to 3 M, the value of m0 could be sharply increased to 5.1 mg/kg even at 95 °C. This variation in the extractable concentration of cesium with the parameters signifies the existence of different binding sites in the soil matrix. The results observed for uncontaminated sample could be reproduced with the radioactive cesium contaminated sample belonging to the same soil group.

  18. Influence of tunnel and soil parameters on vibrations from underground railways

    NASA Astrophysics Data System (ADS)

    Gupta, S.; Stanus, Y.; Lombaert, G.; Degrande, G.

    2009-10-01

    A parametric study is performed to identify the key parameters which have an important influence on the generation and propagation of vibrations from underground railways. In this paper, the parameters related to the tunnel and the soil are considered and their influence on the free field response is studied. The coupled periodic finite element-boundary element model and the pipe-in-pipe model have been used for this study. Both models account for the dynamic interaction between the train, the track, the tunnel and the soil. A general analytical formulation is used to compute the response of three-dimensional invariant or periodic media that are excited by moving loads. The response to moving loads is written in terms of the axle loads and the transfer functions. The parametric study can be carried out by separately analyzing the variations in the axle loads and the transfer functions. The axle loads are mainly influenced by the parameters related to the vehicle and the track, while the transfer functions are influenced by the properties of the track, the tunnel and the soil. In the present paper, the parameters related to the tunnel and soil are investigated. It is observed that the material damping and the shear modulus of the soil have an important influence on the propagation of vibrations. The influence of structural changes to the tunnel as well as geometrical properties such as the size and shape of the tunnel is investigated. It is observed that a larger tunnel results in a smaller response above the tunnel as more energy is radiated downwards. Moreover, it is demonstrated that the tunnel geometry has a considerable influence on the response closer to the tunnel.

  19. Changes in soil parameters under continuous plastic mulching in strawberry cultivation

    NASA Astrophysics Data System (ADS)

    Muñoz, Katherine; Diehl, Dörte; Scopchanova, Sirma; Schaumann, Gabriele E.

    2016-04-01

    Plastic mulching (PM) is a widely used practice in modern agriculture because they generate conditions for optimal yield rates and quality. However, information about long-term effects of PC on soil quality parameters is scarce. The aim of this study is to compare the effect of three different mulching managements on soil quality parameters. Sampling and methodology: Three different managements were studied: Organic mulching (OM), 2-years PM and 4-years PM. Soil samples were collected from irrigated fields in 0-5, 5-10 and 10-30 cm depths and analyzed for water content (WC), pH, dissolved organic carbon (DOC), total soil carbon (Ctot) and cation exchange capacity (CECeff). Results and discussion: Mulching management has an influence on soil parameters. The magnitude of the effects is influenced by the type (organic agriculture practice vs. plastic mulching practice) and duration of the mulching. PM modified the water distribution through the soil column. WC values at the root zone were in average 10% higher compared to those measured at the topsoil. Under OM, the WC was lower than under PM. The pH was mainly influenced by the duration of the managements with slightly higher values after 4 than after 2-years PM. Under PM, aqueous extracts of the topsoil (0-5 cm depth) contained in average with 8.5±1.8 mg/L higher DOC than in 10-30 cm depth with 5.6±0.5 mg/L, which may indicate a mobilization of organic components in the upper layers. After 4-years PM, Ctot values were slightly higher than after 2-years PM and after OM. Surprisingly, after 4-years PM, CECeff values were with 138 - 157 mmolc/kg almost 2-fold higher than after 2-years PM and OM which had with 74 - 102 mmolc/kg comparable CECeff values. Long-term PM resulted in changes of soil pH and slightly increased Ctot which probably enhanced the CECeff of the soil. However, further investigations of the effect of PM on stability of soil organic matter and microbial community structure are needed.

  20. Geology and Petrophysics of the Ozouri Group, Central Gabon

    SciTech Connect

    Dunne, L.A.; Johnson, P.R.; DeSantis, S.B.

    1996-08-01

    The Ozouri Group in Gabon is comprised of finely textured siliceous dolomitic and calcareous claystones, shales, limestones, dolomites, porcellanite and cherts. It was deposited during the Late Paleocene and Early Eocene on a transgressive continental margin. It is highly siliceous and organically rich, with affinities to the Miocene Monterey Formation of California. It is often fractured by deeper structural movement of the underlying Ezanga salt. Economic oil production from the Ozouri is dependent on the most effective combination of matrix (storage) and fracture (deliverability) porosity. The most efficient combination can be related to variations in the lithologic and petrophysical characteristics of the formation. Horizontal drilling techniques can be utilized to fully exploit production from the Ozouri Group.

  1. Estimation of the soil strength parameters in Tertiary volcanic regolith (NE Turkey) using analytical hierarchy process

    NASA Astrophysics Data System (ADS)

    Ersoy, Hakan; Karsli, Melek Betül; Çellek, Seda; Kul, Bilgehan; Baykan, İdris; Parsons, Robert L.

    2013-12-01

    Costly and time consuming testing techniques and the difficulties in providing undisturbed samples for these tests have led researchers to estimate strength parameters of soils with simple index tests. However, the paper focuses on estimation of strength parameters of soils as a function of the index properties. Analytical hierarchy process and multiple regression analysis based methodology were performed on datasets obtained from soil tests on 41 samples in Tertiary volcanic regolith. While the hierarchy model focused on determining the most important index properties affecting on strength parameters, regression analysis established meaningful relationships between strength parameters and index properties. The negative polynomial correlations between the friction angle and plasticity properties, and the positive exponential relations between the cohesion and plasticity properties were determined. These relations are characterized by a regression coefficient of 0.80. However, Terzaghi bearing capacity formulas were used to test the model. It is important to see whether there is any statistically significant relation between the calculated and the observed bearing capacity values for model testing. Based on the model, the positive linear correlation characterized by the regression coefficient of 0.86 were determined between bearing capacity values obtained by direct and indirect methods.

  2. Analysis of effective Green-Ampt hydraulic parameters for vertically layered soils

    NASA Astrophysics Data System (ADS)

    Deng, Peng; Zhu, Jianting

    2016-07-01

    While Green-Ampt model has been widely used in infiltration calculations through unsaturated soils, upscaling this model for applications in heterogeneous formations remains difficult. In this study, how to upscale soil parameters in the Green-Ampt model for vertically layered soils is examined. The main idea of upscaled effective parameters is to capture infiltration behavior in layered soil formations using only one set of parameters derived from the parameters of individual layers, such that the layered system can be replaced by an equivalent homogeneous medium. The general p-order power mean was proposed to represent the upscaling schemes of the Green-Ampt model. The optimal p value was determined by a general requirement of same total infiltration time for the layered formation and the equivalent homogeneous medium. The p-order power mean for the Green-Ampt parameters can capture the infiltration rates in the layered formations well, illustrating that the proposed upscaling schemes are reasonable to represent the overall behaviors of the heterogeneous layered formations. The structure of layered formations can significantly influence the upscaling results. However, when the number of layers becomes large, the layered formations tend to show homogeneity and the layer structure becomes less important. The results demonstrated that the scheme based on the harmonic mean for the saturated hydraulic conductivity and the general p-order power mean for the wetting front suction head can well capture the overall infiltration behaviors in both the coarse-layer-on-top and fine-layer-on-top formations, and thus is recommended as a general upscaling scheme when using the upscaled Green-Ampt model in layered formations.

  3. Petrophysical evaluation of the hydrocarbon potential of the Lower Cretaceous Kharita clastics, North Qarun oil field, Western Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Teama, Mostafa A.; Nabawy, Bassem S.

    2016-09-01

    Based on the available well log data of six wells chosen in the North Qarun oil field in the Western Desert of Egypt, the petrophysical evaluation for the Lower Cretaceous Kharita Formation was accomplished. The lithology of Kharita Formation was analyzed using the neutron porosity-density and the neutron porosity-gamma ray crossplots as well as the litho-saturation plot. The petrophysical parameters, include shale volume, effective porosity, water saturation and hydrocarbon pore volume, were determined and traced laterally in the studied field through the iso-parametric maps. The lithology crossplots of the studied wells show that the sandstone is the main lithology of the Kharita Formation intercalated with some calcareous shale. The cutoff values of shale volume, porosity and water saturation for the productive hydrocarbon pay zones are defined to be 40%, 10% and 50%, respectively, which were determined, based on the applied crossplots approach and their limits. The iso-parametric contour maps for the average reservoir parameters; such as net-pay thickness, average porosity, shale volume, water saturation and the hydrocarbon pore volume were illustrated. From the present study, it is found that the Kharita Formation in the North Qarun oil field has promising reservoir characteristics, particularly in the northwestern part of the study area, which is considered as a prospective area for oil accumulation.

  4. Determining fate and transport parameters for nitroglycerine, 2,4-dinitrotoluine, and nitroguanidine in soils

    NASA Astrophysics Data System (ADS)

    Gosch, D. L.; Dontsova, K.; Chorover, J.; Ferré, T.; Taylor, S.

    2010-12-01

    During military operations, a small fraction of propellant mass is not consumed during firing and is deposited onto the ground surface (Jenkins et al., 2006). Soluble propellant constituents can be released from particulate residues into the environment. Propellant constituents of interest for this study are nitroglycerine (NG), 2,4-dinitrotoluine (2,4-DNT), 2,6-dinitrotoluine (2,6-DNT), and nitroguanidine (NQ). The goal of this work is to determine fate and transport parameters for these constituents in three soils that represent a range of geographic locations and soil properties. This supports a companion study that looks at dissolution of NG, 2,4-DNT, 2,6-DNT, and NQ from fired and unfired solid propellant formulations and their transport in soils. The three soils selected for the study are Catlin silt loam (fine-silty, mixed, mesic, superactive Oxyaquic Argiudoll), Plymouth sandy loam (mesic, coated Typic Quartzipsamment), and Sassafras loam (fine loamy, siliceous, mesic Typic Hapudult). Two of these soils, Plymouth sandy loam and Sassafras loam, were collected on military installations. Linear adsorption coefficients and transformation rates of propellant constituents were determined in batch kinetic experiments. Soils were mixed with propellant constituent solutions (2 mg L-1) at 4:1 solution/soil mass ratio and equilibrated for 0, 1, 2, 6, 12, 24, 48, and 120 hr at which time samples were centrifuged and supernatant solutions were analyzed for target compounds by high performance liquid chromatography (HPLC) using U.S. EPA Method 8330b for NG, 2,4-DNT, and 2,6-DNT, and Walsh (1989) method for NQ. Adsorption and transformation of propellant constituents were determined from the decrease in solution concentration of these compounds. It was determined that all studied compounds were subjected to sorption by the solid phase and degradation. Catlin soil, with finer texture and high organic matter content, influenced solution concentration of NG, 2,4-DNT, 2,6-DNT

  5. Relations among soil radon, environmental parameters, volcanic and seismic events at Mt. Etna (Italy)

    NASA Astrophysics Data System (ADS)

    Giammanco, S.; Ferrera, E.; Cannata, A.; Montalto, P.; Neri, M.

    2013-12-01

    From November 2009 to April 2011 soil radon activity was continuously monitored using a Barasol probe located on the upper NE flank of Mt. Etna volcano (Italy), close both to the Piano Provenzana fault and to the NE-Rift. Seismic, volcanological and radon data were analysed together with data on environmental parameters, such as air and soil temperature, barometric pressure, snow and rain fall. In order to find possible correlations among the above parameters, and hence to reveal possible anomalous trends in the radon time-series, we used different statistical methods: i) multivariate linear regression; ii) cross-correlation; iii) coherence analysis through wavelet transform. Multivariate regression indicated a modest influence on soil radon from environmental parameters (R2 = 0.31). When using 100-day time windows, the R2 values showed wide variations in time, reaching their maxima (~0.63-0.66) during summer. Cross-correlation analysis over 100-day moving averages showed that, similar to multivariate linear regression analysis, the summer period was characterised by the best correlation between radon data and environmental parameters. Lastly, the wavelet coherence analysis allowed a multi-resolution coherence analysis of the time series acquired. This approach allowed to study the relations among different signals either in the time or in the frequency domain. It confirmed the results of the previous methods, but also allowed to recognize correlations between radon and environmental parameters at different observation scales (e.g., radon activity changed during strong precipitations, but also during anomalous variations of soil temperature uncorrelated with seasonal fluctuations). Using the above analysis, two periods were recognized when radon variations were significantly correlated with marked soil temperature changes and also with local seismic or volcanic activity. This allowed to produce two different physical models of soil gas transport that explain the

  6. Using a scoop to derive soil mechanical parameters on the surface of Mars

    NASA Astrophysics Data System (ADS)

    Kargl, Günter; Poganski, Joshua; Kömle, Norbert I.; Schweiger, Helmut; Macher, Wolfgang

    2016-04-01

    We will report on the possibility of using the scoop attached to the instrument deployment arm to perform soil mechanical experiments directly on the surface of Mars. The Phoenix mission flown 2009 had an instrument deployment arm which was also used to sample surface material indo instruments mounted on the lander deck. The flight spare of this arm will again be flown to Mars on board the InSight mission. Although, the primary purpose of the arm and the attached scoop was not soil mechanical investigations it was already demonstrated by the Phoenix mission that the arm can be used to perform auxiliary investigations of the surface materials. We will report on modelling efforts using a Discrete Element Software package to demonstrate that simple soil mechanical experiments can be used to derive essential material parameters like e.g. angle of repose and others. This is of particular interest since it would be possible to implement experiments using the hardware of the InSight mission. PIC Cross section cut through a trench dug out by the scoop and the pile of the deposed material which both can be used to derive soil mechanical parameters.

  7. Estimation of uncertainty arising from different soil sampling devices: the use of variogram parameters.

    PubMed

    de Zorzi, Paolo; Barbizzi, Sabrina; Belli, Maria; Barbina, Maria; Fajgelj, Ales; Jacimovic, Radojko; Jeran, Zvonka; Menegon, Sandro; Pati, Alessandra; Petruzzelli, Giannantonio; Sansone, Umberto; Van der Perk, Marcel

    2008-01-01

    In the frame of the international SOILSAMP project, funded and coordinated by the National Environmental Protection Agency of Italy (APAT), uncertainties due to field soil sampling were assessed. Three different sampling devices were applied in an agricultural area using the same sampling protocol. Cr, Sc and Zn mass fractions in the collected soil samples were measured by k(0)-instrumental neutron activation analysis (k(0)-INAA). For each element-device combination the experimental variograms were calculated using geostatistical tools. The variogram parameters were used to estimate the standard uncertainty arising from sampling. The sampling component represents the dominant contribution of the measurement uncertainty with a sampling uncertainty to measurement uncertainty ratio ranging between 0.6 and 0.9. The approach based on the use of variogram parameters leads to uncertainty values of the sampling component in agreement with those estimated by replicate sampling approach.

  8. APPLICABILITY OF A ACCUMULATED DAMAGE PARAMETER METHOD ON SOIL LIQUEFACTION DUE TOSEVERAL EARTHQUAKES

    NASA Astrophysics Data System (ADS)

    Izawa, Jun; Tanoue, Kazuya; Murono, Yoshitaka

    Severe soil liquefaction due to long duration earthquake with low acceleration occurred at Tokyo Bay area in the 2011 off the Pacific coast of Tohoku Earthquake. This phenomenon clearly shows that soil liquefaction is affected by properties of input waves. This paper describes effect of wave properties of earthquake on liquefaction using Effective Stress analysis with some earthquakes. Analytical result showedthat almost the same pore water pressure was observed due to both long durationearthquake with max acceleration of 150Gal and typical inland active fault earthquake with 891Gal. Additionally, lique-faction potentials for each earthquake were evaluated by simple judgment with accumulated damage parameter, which is used for design of railway structuresin Japan. As a result, it was found that accurate liquefaction resistance on large cyclic area is necessaryto evaluate liquefaction potential due to long duration earthquake with low acceleration with simple judgment with accumulated damage parameter.

  9. New petrophysical magnetic methods MACC and MAFM in permeability characterisation of petroleum reservoir rock cleaning, flooding modelling and determination of fines migration in formation damage

    NASA Astrophysics Data System (ADS)

    Ivakhnenko, O. P.

    2012-04-01

    Potential applications of magnetic techniques and methods in petroleum engineering and petrophysics (Ivakhnenko, 1999, 2006; Ivakhnenko & Potter, 2004) reveal their vast advantages for the petroleum reservoir characterisation and formation evaluation. In this work author proposes for the first time developed systematic methods of the Magnetic Analysis of Core Cleaning (MACC) and Magnetic Analysis of Fines Migration (MAFM) for characterisation of reservoir core cleaning and modelling estimations of fines migration for the petroleum reservoir formations. Using example of the one oil field we demonstrate results in application of these methods on the reservoir samples. Petroleum reservoir cores samples have been collected within reservoir using routine technique of reservoir sampling and preservation for PVT analysis. Immediately before the MACC and MAFM studies samples have been exposed to atmospheric air for a few days. The selected samples have been in detailed way characterised after fluid cleaning and core flooding by their mineralogical compositions and petrophysical parameters. Mineralogical composition has been estimated utilizing XRD techniques. The petrophysical parameters, such as permeability and porosity have been measured on the basis of total core analysis. The results demonstrate effectiveness and importance of the MACC and MAFM methods for the routine core analysis (RCAL) and the special core analysis (SCAL) in the reservoir characterisation, core flooding and formation damage analysis.

  10. Prediction of ecotoxicity of hydrocarbon-contaminated soils using physicochemical parameters

    SciTech Connect

    Wong, D.C.L.; Chai, E.Y.; Chu, K.K.; Dorn, P.B.

    1999-11-01

    The physicochemical properties of eight hydrocarbon-contaminated soils were used to predict toxicity to earthworms (Eisenia fetida) and plants. The toxicity of these preremediated soils was assessed using earthworm avoidance, survival, and reproduction and seed germination and root growth in four plant species. No-observed-effect and 25% inhibitory concentrations were determined from the earthworm and plant assays. Physical property measurements and metals analyses of the soils were conducted. Hydrocarbon contamination was characterized by total petroleum hydrocarbons, oil and grease, and GC boiling-point distribution. Univariate and multivariate statistical methods were used to examine relationships between physical and chemical properties and biological endpoints. Soil groupings based on physicochemical properties and toxicity from cluster and principal component analyses were generally similar. Correlation analysis identified a number of significant relationships between soil parameters and toxicity that were used in univariate model development. Total petroleum hydrocarbons by gas chromatography and polars were identified as predictors of earthworm avoidance and survival and seed germination, explaining 65 to 75% of the variation in the data. Asphaltenes also explained 83% of the variation in seed germination. Gravimetric total petroleum hydrocarbons explained 40% of the variation in earthworm reproduction, whereas 43% of the variation in plant root growth was explained by asphaltenes. Multivariate one-component partial least squares models, which identified predictors similar to those identified by the univariate models, were also developed for worm avoidance and survival and seed germination and had predictive powers of 42 and 29%, respectively.

  11. Assessment of soil electromagnetic parameters and their variation with soil water, salts: a comparison among EMI and TDR measuring methods

    NASA Astrophysics Data System (ADS)

    Chaali, Nesrine; Coppola, Antonio; Comegna, Alessandro; Dragonetti, Giovanna

    2015-04-01

    Numerous studies have analyzed the possibility of the extension of Electromagnetic Induction EMI calibration coefficients determined at field scale, to predict the depth distribution of bulk electrical conductivity ECb within unmonitored sites and/or times, in order to appraise the effect of salts dynamics on soils and plants. However, in the literature, it has been determined that the extension of those EMI calibration coefficients can be awkward since the calibration parameters are highly site-specific because of changes in water content, temperature, root development, soil physical properties, etc... So they can only be used in sites having similar characteristics in terms of EMI. Furthermore there is a difference in the observation windows of EMI sensors and of sensors (Time Domain Reflectometry TDR, Electrical Resistance Tomography ERT, ect...) used for measuring the ECb to be then used for the calibration and validation of the EMI. By consequence the actual variability of the soil salinity will be hidden due to the fact that data coming from EMI and other sensors have different variability patterns and structure, and are then influenced by different noises. The main objectives of this work were: 1) develop a practical and cost-effective technique that uses TDR data as ground-truth data for calibrating and validating of the EMI larger scale sensor, 2) using a Fourier transform FT analysis by applying a specific noise filter to the original data, to find the correlations between the TDR and the EMI data. An experiment was designed by irrigating three transects of green beans, 30 m long each, with three irrigation salinity inputs (1dSm-1, 3dSm-1, 6dSm-1). The irrigation volumes were estimated by measuring soil water content at different depths by using a Diviner 2000. During the experiment, the EM in both the vertical (EMV) and horizontal (EMH) configurations were regularly measured by a Geonics EM38 device. TDR probes were inserted vertically at the soil

  12. Assessing Tillage Effects on Soil Hydraulic Properties via Inverse Parameter Estimation using Tension Infiltrometry

    NASA Astrophysics Data System (ADS)

    Schwen, Andreas; Bodner, Gernot; Loiskandl, Willibald

    2010-05-01

    Hydraulic properties are key factors controlling water and solute movement in soils. While several recent studies have focused on the assessment of the spatial variability of hydraulic properties, the temporal dynamics are commonly not taken into account, primarily because its measurement is costly and time-consuming. However, there is extensive empirical evidence that these properties are subject to temporal changes, particularly in the near-saturated range where soil structure strongly influences water flow. One main source of temporal variability is soil tillage. It can improve macroporosity by loosening the soil and thereby changing the pore-size distribution. Since these modifications are quite unstable over time, the pore space partially collapses after tillage. This effect should be largest for conventional tillage (CT), where the soil is ploughed after harvest every year. Assessing the effect of different tillage treatments on the temporal variability of hydraulic properties requires adequate measurement techniques. Tension infiltrometry has become a popular and convenient method providing not only the hydraulic conductivity function but also the soil rentention properties. The inverse estimation of parameters from infiltration measurements remains challenging, despite some progress since the first approach of Šimůnek et al. (1998). Measured data like the cumulative infiltration, the initial and final volumetric water content, as well as independently measured retention data from soil core analysis with laboratory methods, have to be considered to find an optimum solution describing the soil's pore space. In the present study we analysed tension infiltration measurements obtained several times between August 2008 and December 2009 on an arable field in the Moravian Basin, Lower Austria. The tillage treatments were conventional tillage including ploughing (CT), reduced tillage with chisel only (RT), and no-tillage treatment using a direct seeding

  13. Application of stochastic parameter optimization to the Sacramento Soil Moisture Accounting model

    NASA Astrophysics Data System (ADS)

    Vrugt, Jasper A.; Gupta, Hoshin V.; Dekker, Stefan C.; Sorooshian, Soroosh; Wagener, Thorsten; Bouten, Willem

    2006-06-01

    Hydrological models generally contain parameters that cannot be measured directly, but can only be meaningfully inferred by calibration against a historical record of input-output data. While considerable progress has been made in the development and application of automatic procedures for model calibration, such methods have received criticism for their lack of rigor in treating uncertainty in the parameter estimates. In this paper, we apply the recently developed Shuffled Complex Evolution Metropolis algorithm (SCEM-UA) to stochastic calibration of the parameters in the Sacramento Soil Moisture Accounting model (SAC-SMA) model using historical data from the Leaf River in Mississippi. The SCEM-UA algorithm is a Markov Chain Monte Carlo sampler that provides an estimate of the most likely parameter set and underlying posterior distribution within a single optimization run. In particular, we explore the relationship between the length and variability of the streamflow data and the Bayesian uncertainty associated with the SAC-SMA model parameters and compare SCEM-UA derived parameter values with those obtained using deterministic SCE-UA calibrations. Most significantly, for the Leaf River catchments under study our results demonstrate that most of the 13 SAC-SMA parameters are well identified by calibration to daily streamflow data suggesting that this data contains more information than has previously been reported in the literature.

  14. Magnetic Parameter Changes in Soil and Sediments in the Presence of Hydrocarbon Contamination

    NASA Astrophysics Data System (ADS)

    Appel, E.; Porsch, K.; Rijal, M. L.; Ameen, N. N.; Kappler, A.

    2014-12-01

    Magnetic proxies were successfully used for fast and non-destructive detection of fly ash related heavy metal pollution. Correlations of magnetic signals with organic contaminants in soils and sediments were also reported; however, their significance is unclear because of co-existing heavy metal pollution. At a hydrocarbon (HC) contaminated former military airbase (Hradcany, Czech Rep.), where heavy metal contents are insignificant, we detected clearly higher magnetic concentrations at the top of the groundwater fluctuation (GWF) zone. Frequent GWF by up to ca. one meter was caused through remediation by air sparging. In this study and all previous ones magnetite was identified as the dominant phase for higher magnetic concentrations. To determine the importance of microbial activity and soil parameters on changes in magnetic susceptibility (MS) laboratory batch experiments with different microbially active and sterile soils without carbon addition and with gasoline amendment were setup. MS of these microcosms was followed weekly. Depending on the soil MS either increased or decreased by up to ~7% and remained constant afterwards. The main findings were that MS changes were mainly microbially driven and influenced by the bioavailable Fe content, the initial MS and the organic carbon content of the soils. Moreover, we tested magnetic changes in laboratory columns, filled with sand from the field site Hradcany, by simulating water level changes. The observed changes were small and hardly statistically significant. Our laboratory studies revealed that different factors influence changes in magnetic properties of soil/sediments after HC contamination, with much smaller effects than expected from anomalies observed at field sites. With the present results, the ambitious goal of using magnetic monitoring for detecting HC contaminations by oil spills seem far from practical application.

  15. Simulating solute transport in a structured field soil: uncertainty in parameter identification and predictions.

    PubMed

    Larsbo, Mats; Jarvis, Nicholas

    2005-01-01

    Dual-permeability models have been developed to account for the significant effects of macropore flow on contaminant transport, but their use is hampered by difficulties in estimating the additional parameters required. Therefore, our objective was to evaluate data requirements for parameter identification for predictive modeling with the dual-permeability model MACRO. Two different approaches were compared: sequential uncertainty fitting (SUFI) and generalized likelihood uncertainty estimation (GLUE). We investigated six parameters controlling macropore flow and pesticide sorption and degradation, applying MACRO to a comprehensive field data set of bromide andbentazone [3-isopropyl-1H-2,1,3-benzothiadiazin-4(3H)-one-2,2dioxide] transport in a structured soil. The GLUE analyses of parameter conditioning for different combinations of observations showed that both resident and flux concentrations were needed to obtain highly conditioned and unbiased parameters and that observations of tracer transport generally improved the conditioning of macropore flow parameters. The GLUE "behavioral" parameter sets covered wider parameter ranges than the SUFI posterior uncertainty domains. Nevertheless, estimation uncertainty ranges defined by the 5th and 95th percentiles were similar and many simulations randomly sampled from the SUFI posterior uncertainty domains had negative model efficiencies (minimum of -3.2). This is because parameter correlations are neglected in SUFI and the posterior uncertainty domains were not always determined correctly. For the same reasons, uncertainty ranges for predictions of bentazone losses through drainflow for good agricultural practice in southern Sweden were 27% larger for SUFI compared with GLUE. Although SUFI proved to be an efficient parameter estimation tool, GLUE seems better suited as a method of uncertainty estimation for predictions.

  16. Petrophysical correlation of Fennoscandian magnetic and gravity anomalies

    NASA Astrophysics Data System (ADS)

    Korhonen, J. V.; Säävuori, H.; Koistinen, T.; Working GroupFennoscandian Geophysical Maps

    2003-04-01

    Magnetic anomaly, Bouguer-anomaly and petrophysical grids of the Fennoscandian shield and adjoining area have been compiled as a joint venture between Finland, Norway, Sweden and Russia, and with contribution of Denmark, Estonia, Latvia and Lithuania. Maps have been printed on a scale of 1:2 million. The aim was to provide an overall view of the anomaly structure of the area, and especially assist in correlating Precambrian geological formations across seas, state borders and areas covered by younger formations. Insert maps on a scale of 1:15 million are aimed to correlate anomaly components in different source scales: pseudogravimetric anomaly with Bouguer anomaly, DGRF-65 anomaly with pseudomagnetic anomaly, magnetic vertical derivative with second derivative of Bouguer anomaly. Data on bulk density, total magnetisation, Q-value and lithology of samples have been presented as scatter diagrams and average distribution maps to delineate variation and evolution trends of properties in space and time. Major anomalies of the Bouguer-anomaly map are due to Caledonian and Belomorian zones, Rapakivi granites and high metamorphic blocks in central area of the shield. Magnetic positive regional anomalies are due to granite areas in the north and west and to high-grade rocks in south. The central magnetic low is associated with rocks of supracrustal origin. Bouguer anomaly and depth-integrated magnetisation were compared with average bulk density and total magnetisation to find information on depth extent of exposed anomaly sources. The source magnetisation of the north Fennoscandian magnetic high is interpreted to reach 10 km in depth. The source area extends to the west under the Caledonian cover and to the east under the granite area of Central Finnish Lapland. The thickness of the latter is a few km only, as interpreted by density -- gravity correlation. In SE Fennoscandia the thickness of Wiborg rapakivi is c. 10 km by bulk density, and thickness of North Estonian

  17. Hydrothermal carbonization of biomass from landscape management - Influence of process parameters on soil properties of hydrochars.

    PubMed

    Röhrdanz, Michael; Rebling, Tammo; Ohlert, Jan; Jasper, Jan; Greve, Thomas; Buchwald, Rainer; von Frieling, Petra; Wark, Michael

    2016-05-15

    Besides pyrolysis the technology of hydrothermal carbonization (HTC) is tested to produce hydrochars for soil improvement. The chemical and physical properties of the hydrochars mainly depend on the feedstock and the process parameters reaction time and process temperature. Systematic investigations on the influences of these process parameters on soil properties of hydrochars like water holding capacity (WHC) and cation exchange capacity (CEC) are missing. In this study, a rush-rich biomass was carbonized within defined HTC process conditions under variation of reaction time and process temperature to produce hydrochars. Analysis of WHC, CEC, the elemental composition and Fourier-transform infrared spectroscopy (FT-IR) were performed to evaluate the influence of HTC process conditions on the pedological hydrochar properties. The results indicated that at increasing reaction severity (reaction time and process temperature) WHC and CEC decreased as well as the elemental O/C ratio. The decrease of WHC and CEC is based on the decrease of the hydrochar surface polarity. However, even the lowest WHC and CEC of investigated hydrochars still exceeded those of pure quartz sand by factors of 5-10. An application of hydrochars produced at severe HTC conditions could improve WHC and CEC of sandy soils. This has to be investigated in further studies. PMID:26974240

  18. Soil biochar amendment as a climate change mitigation tool: Key parameters and mechanisms involved.

    PubMed

    Brassard, Patrick; Godbout, Stéphane; Raghavan, Vijaya

    2016-10-01

    Biochar, a solid porous material obtained from the carbonization of biomass under low or no oxygen conditions, has been proposed as a climate change mitigation tool because it is expected to sequester carbon (C) for centuries and to reduce greenhouse gas (GHG) emissions from soils. This review aimed to identify key biochar properties and production parameters that have an effect on these specific applications of the biochar. Moreover, mechanisms involved in interactions between biochar and soils were highlighted. Following a compilation and comparison of the characteristics of 76 biochars from 40 research studies, biochars with a lower N content, and consequently a higher C/N ratio (>30), were found to be more suitable for mitigation of N2O emissions from soils. Moreover, biochars produced at a higher pyrolysis temperature, and with O/C ratio <0.2, H/Corg ratio <0.4 and volatile matter below 80% may have high C sequestration potential. Based on these observations, biochar production and application to the field can be used as a tool to mitigate climate change. However, it is important to determine the pyrolysis conditions and feedstock needed to produce a biochar with the desired properties for a specific application. More research studies are needed to identify the exact mechanisms involved following biochar amendment to soil.

  19. Soil biochar amendment as a climate change mitigation tool: Key parameters and mechanisms involved.

    PubMed

    Brassard, Patrick; Godbout, Stéphane; Raghavan, Vijaya

    2016-10-01

    Biochar, a solid porous material obtained from the carbonization of biomass under low or no oxygen conditions, has been proposed as a climate change mitigation tool because it is expected to sequester carbon (C) for centuries and to reduce greenhouse gas (GHG) emissions from soils. This review aimed to identify key biochar properties and production parameters that have an effect on these specific applications of the biochar. Moreover, mechanisms involved in interactions between biochar and soils were highlighted. Following a compilation and comparison of the characteristics of 76 biochars from 40 research studies, biochars with a lower N content, and consequently a higher C/N ratio (>30), were found to be more suitable for mitigation of N2O emissions from soils. Moreover, biochars produced at a higher pyrolysis temperature, and with O/C ratio <0.2, H/Corg ratio <0.4 and volatile matter below 80% may have high C sequestration potential. Based on these observations, biochar production and application to the field can be used as a tool to mitigate climate change. However, it is important to determine the pyrolysis conditions and feedstock needed to produce a biochar with the desired properties for a specific application. More research studies are needed to identify the exact mechanisms involved following biochar amendment to soil. PMID:27420171

  20. High resolution petrophysical and geomechanical logging of drill cores as a tool for the evaluation of dimension stone quality and durability

    NASA Astrophysics Data System (ADS)

    Prikryl, Richard; Lokajíček, Tomáš; Weishauptová, Zuzana; Petružálek, Matěj

    2015-04-01

    Petrophysical and geomechanical properties are significant functional properties of natural stone. In the recent study, an approach employing the entire non-disturb parts of drill cores for determination of the key petrophysical and geomechanical parameters is presented. The drill cores have been obtained during exploration campaign for Carboniferous arkoses and arkosic sandstones to conglomerates in the Bohemian Massif (Czech Republic). The test procedure consists of the sequence of non-destructive methods including determination of index properties, ultrasonic characteristics (speed of longitudinal and transversal waves, recording of the full waveforms). Once non-destructively tested, the specimens are subjected to standard compressive and/or tensile tests encompassing recording of stress-strain behaviour. Broad range of values obtained reflects quite complex petrographical character of rocks investigated. Variable grain size, grain size homogeneity, degree of cementation, overall rock microfabric, and/or presence and distribution of inter- and intraparticle porosity seem to be determinative factors. Once calibrated for a particular petrographical characteristics, high resolution petrophysical and geomechanical logging (HRPGL) can serve as an effective tool for precise evaluation of exploitable natural stone quality.

  1. Lignin decomposition along an Alpine elevation gradient in relation to physicochemical and soil microbial parameters.

    PubMed

    Duboc, Olivier; Dignac, Marie-France; Djukic, Ika; Zehetner, Franz; Gerzabek, Martin H; Rumpel, Cornelia

    2014-07-01

    Lignin is an aromatic plant compound that decomposes more slowly than other organic matter compounds; however, it was recently shown that lignin could decompose as fast as litter bulk carbon in minerals soils. In alpine Histosols, where organic matter dynamics is largely unaffected by mineral constituents, lignin may be an important part of soil organic matter (SOM). These soils are expected to experience alterations in temperature and/or physicochemical parameters as a result of global climate change. The effect of these changes on lignin dynamics remains to be examined and the importance of lignin as SOM compound in these soils evaluated. Here, we investigated the decomposition of individual lignin phenols of maize litter incubated for 2 years in-situ in Histosols on an Alpine elevation gradient (900, 1300, and 1900 m above sea level); to this end, we used the cupric oxide oxidation method and determined the phenols' (13) C signature. Maize lignin decomposed faster than bulk maize carbon in the first year (86 vs. 78% decomposed); however, after the second year, lignin and bulk C decomposition did not differ significantly. Lignin mass loss did not correlate with soil temperature after the first year, and even correlated negatively at the end of the second year. Lignin mass loss also correlated negatively with the remaining maize N at the end of the second year, and we interpreted this result as a possible negative influence of nitrogen on lignin degradation, although other factors (notably the depletion of easily degradable carbon sources) may also have played a role at this stage of decomposition. Microbial community composition did not correlate with lignin mass loss, but it did so with the lignin degradation indicators (Ac/Al)s and S/V after 2 years of decomposition. Progressing substrate decomposition toward the final stages thus appears to be linked with microbial community differentiation. PMID:24323640

  2. Lignin decomposition along an Alpine elevation gradient in relation to physicochemical and soil microbial parameters.

    PubMed

    Duboc, Olivier; Dignac, Marie-France; Djukic, Ika; Zehetner, Franz; Gerzabek, Martin H; Rumpel, Cornelia

    2014-07-01

    Lignin is an aromatic plant compound that decomposes more slowly than other organic matter compounds; however, it was recently shown that lignin could decompose as fast as litter bulk carbon in minerals soils. In alpine Histosols, where organic matter dynamics is largely unaffected by mineral constituents, lignin may be an important part of soil organic matter (SOM). These soils are expected to experience alterations in temperature and/or physicochemical parameters as a result of global climate change. The effect of these changes on lignin dynamics remains to be examined and the importance of lignin as SOM compound in these soils evaluated. Here, we investigated the decomposition of individual lignin phenols of maize litter incubated for 2 years in-situ in Histosols on an Alpine elevation gradient (900, 1300, and 1900 m above sea level); to this end, we used the cupric oxide oxidation method and determined the phenols' (13) C signature. Maize lignin decomposed faster than bulk maize carbon in the first year (86 vs. 78% decomposed); however, after the second year, lignin and bulk C decomposition did not differ significantly. Lignin mass loss did not correlate with soil temperature after the first year, and even correlated negatively at the end of the second year. Lignin mass loss also correlated negatively with the remaining maize N at the end of the second year, and we interpreted this result as a possible negative influence of nitrogen on lignin degradation, although other factors (notably the depletion of easily degradable carbon sources) may also have played a role at this stage of decomposition. Microbial community composition did not correlate with lignin mass loss, but it did so with the lignin degradation indicators (Ac/Al)s and S/V after 2 years of decomposition. Progressing substrate decomposition toward the final stages thus appears to be linked with microbial community differentiation.

  3. A soil parameters geodatabase for the modeling assessment of agricultural conservation practices effects in the United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil parameters for hydrology modeling in cropland dominated areas, from the regional to local scale, are part of critical biophysical information whose deficiency may increase the uncertainty of simulated conservation effects and predicting potential. Despite this importance, soil physical and hyd...

  4. Predicting Cereal Root Disease in Western Australia Using Soil DNA and Environmental Parameters.

    PubMed

    Poole, Grant J; Harries, Martin; Hüberli, D; Miyan, S; MacLeod, W J; Lawes, Roger; McKay, A

    2015-08-01

    Root diseases have long been prevalent in Australian grain-growing regions, and most management decisions to reduce the risk of yield loss need to be implemented before the crop is sown. The levels of pathogens that cause the major root diseases can be measured using DNA-based services such as PreDicta B. Although these pathogens are often studied individually, in the field they often occur as mixed populations and their combined effect on crop production is likely to vary across diverse cropping environments. A 3-year survey was conducted covering most cropping regions in Western Australia, utilizing PreDicta B to determine soilborne pathogen levels and visual assessments to score root health and incidence of individual crop root diseases caused by the major root pathogens, including Rhizoctonia solani (anastomosis group [AG]-8), Gaeumannomyces graminis var. tritici (take-all), Fusarium pseudograminearum, and Pratylenchus spp. (root-lesion nematodes) on wheat roots for 115, 50, and 94 fields during 2010, 2011, and 2012, respectively. A predictive model was developed for root health utilizing autumn and summer rainfall and soil temperature parameters. The model showed that pathogen DNA explained 16, 5, and 2% of the variation in root health whereas environmental parameters explained 22, 11, and 1% of the variation in 2010, 2011, and 2012, respectively. Results showed that R. solani AG-8 soil pathogen DNA, environmental soil temperature, and rainfall parameters explained most of the variation in the root health. This research shows that interactions between environment and pathogen levels before seeding can be utilized in predictive models to improve assessment of risk from root diseases to assist growers to plan more profitable cropping programs.

  5. Fuzzy ruling between core porosity and petrophysical logs: Subtractive clustering vs. genetic algorithm-pattern search

    NASA Astrophysics Data System (ADS)

    Bagheripour, Parisa; Asoodeh, Mojtaba

    2013-12-01

    Porosity, the void portion of reservoir rocks, determines the volume of hydrocarbon accumulation and has a great control on assessment and development of hydrocarbon reservoirs. Accurate determination of porosity from core analysis is highly cost, time, and labor intensive. Therefore, the mission of finding an accurate, fast and cheap way of determining porosity is unavoidable. On the other hand, conventional well log data, available in almost all wells contain invaluable implicit information about the porosity. Therefore, an intelligent system can explicate this information. Fuzzy logic is a powerful tool for handling geosciences problem which is associated with uncertainty. However, determination of the best fuzzy formulation is still an issue. This study purposes an improved strategy, called hybrid genetic algorithm-pattern search (GA-PS) technique, against the widely held subtractive clustering (SC) method for setting up fuzzy rules between core porosity and petrophysical logs. Hybrid GA-PS technique is capable of extracting optimal parameters for fuzzy clusters (membership functions) which consequently results in the best fuzzy formulation. Results indicate that GA-PS technique manipulates both mean and variance of Gaussian membership functions contrary to SC that only has a control on mean of Gaussian membership functions. A comparison between hybrid GA-PS technique and SC method confirmed the superiority of GA-PS technique in setting up fuzzy rules. The proposed strategy was successfully applied to one of the Iranian carbonate reservoir rocks.

  6. Integration of Seismic and Petrophysics to Characterize Reservoirs in “ALA” Oil Field, Niger Delta

    PubMed Central

    Alao, P. A.; Olabode, S. O.; Opeloye, S. A.

    2013-01-01

    In the exploration and production business, by far the largest component of geophysical spending is driven by the need to characterize (potential) reservoirs. The simple reason is that better reservoir characterization means higher success rates and fewer wells for reservoir exploitation. In this research work, seismic and well log data were integrated in characterizing the reservoirs on “ALA” field in Niger Delta. Three-dimensional seismic data was used to identify the faults and map the horizons. Petrophysical parameters and time-depth structure maps were obtained. Seismic attributes was also employed in characterizing the reservoirs. Seven hydrocarbon-bearing reservoirs with thickness ranging from 9.9 to 71.6 m were delineated. Structural maps of horizons in six wells containing hydrocarbon-bearing zones with tops and bottoms at range of −2,453 to −3,950 m were generated; this portrayed the trapping mechanism to be mainly fault-assisted anticlinal closures. The identified prospective zones have good porosity, permeability, and hydrocarbon saturation. The environments of deposition were identified from log shapes which indicate a transitional-to-deltaic depositional environment. In this research work, new prospects have been recommended for drilling and further research work. Geochemical and biostratigraphic studies should be done to better characterize the reservoirs and reliably interpret the depositional environments. PMID:24068883

  7. Integration of seismic and petrophysics to characterize reservoirs in "ALA" oil field, Niger Delta.

    PubMed

    Alao, P A; Olabode, S O; Opeloye, S A

    2013-01-01

    In the exploration and production business, by far the largest component of geophysical spending is driven by the need to characterize (potential) reservoirs. The simple reason is that better reservoir characterization means higher success rates and fewer wells for reservoir exploitation. In this research work, seismic and well log data were integrated in characterizing the reservoirs on "ALA" field in Niger Delta. Three-dimensional seismic data was used to identify the faults and map the horizons. Petrophysical parameters and time-depth structure maps were obtained. Seismic attributes was also employed in characterizing the reservoirs. Seven hydrocarbon-bearing reservoirs with thickness ranging from 9.9 to 71.6 m were delineated. Structural maps of horizons in six wells containing hydrocarbon-bearing zones with tops and bottoms at range of -2,453 to -3,950 m were generated; this portrayed the trapping mechanism to be mainly fault-assisted anticlinal closures. The identified prospective zones have good porosity, permeability, and hydrocarbon saturation. The environments of deposition were identified from log shapes which indicate a transitional-to-deltaic depositional environment. In this research work, new prospects have been recommended for drilling and further research work. Geochemical and biostratigraphic studies should be done to better characterize the reservoirs and reliably interpret the depositional environments. PMID:24068883

  8. Petrophysical and paleomagnetic data of drill cores from the Bosumtwi impact structure, Ghana

    NASA Astrophysics Data System (ADS)

    Elbra, T.; Kontny, A.; Pesonen, L. J.; Schleifer, N.; Schell, C.

    Physical properties from rocks of the Bosumtwi impact structure, Ghana, Central Africa, are essential to understand the formation of the relatively young (1.07 Ma) and small (10.5 km) impact crater and to improve its geophysical modeling. Results of our petrophysical studies of deep drill cores LB-07A and LB-08A reveal distinct lithological patterns but no depth dependence. The most conspicuous difference between impactites and target lithologies are the lower bulk densities and significantly higher porosities of the suevite and lithic breccia units compared to meta-graywacke and metapelites of target lithologies. Magnetic susceptibility shows mostly paramagnetic values (200-500 × 10-6 SI) throughout the core, with an exception of a few metasediment samples, and correlates positively with natural remanent magnetization (NRM) and Q values. These data indicate that magnetic parameters are related to inhomogeneously distributed ferrimagnetic pyrrhotite. The paleomagnetic data reveals that the characteristic direction of NRM has shallow normal (in a few cases shallow reversed) polarity, which is in agreement with the Lower Jaramillo N-polarity chron direction, and is carried by ferrimagnetic pyrrhotite. However, our study has not revealed the expected high magnetization body required from previous magnetic modeling. Furthermore, the LB-07A and LB08-A drill cores did not show the predicted high content of melt in the rocks, requiring a new interpretation model for magnetic data.

  9. Integration of seismic and petrophysics to characterize reservoirs in "ALA" oil field, Niger Delta.

    PubMed

    Alao, P A; Olabode, S O; Opeloye, S A

    2013-01-01

    In the exploration and production business, by far the largest component of geophysical spending is driven by the need to characterize (potential) reservoirs. The simple reason is that better reservoir characterization means higher success rates and fewer wells for reservoir exploitation. In this research work, seismic and well log data were integrated in characterizing the reservoirs on "ALA" field in Niger Delta. Three-dimensional seismic data was used to identify the faults and map the horizons. Petrophysical parameters and time-depth structure maps were obtained. Seismic attributes was also employed in characterizing the reservoirs. Seven hydrocarbon-bearing reservoirs with thickness ranging from 9.9 to 71.6 m were delineated. Structural maps of horizons in six wells containing hydrocarbon-bearing zones with tops and bottoms at range of -2,453 to -3,950 m were generated; this portrayed the trapping mechanism to be mainly fault-assisted anticlinal closures. The identified prospective zones have good porosity, permeability, and hydrocarbon saturation. The environments of deposition were identified from log shapes which indicate a transitional-to-deltaic depositional environment. In this research work, new prospects have been recommended for drilling and further research work. Geochemical and biostratigraphic studies should be done to better characterize the reservoirs and reliably interpret the depositional environments.

  10. Sensitivity of water stress in a two-layered sandy grassland soil to variations in groundwater depth and soil hydraulic parameters

    NASA Astrophysics Data System (ADS)

    Rezaei, M.; Seuntjens, P.; Joris, I.; Boënne, W.; Van Hoey, S.; Campling, P.; Cornelis, W. M.

    2015-07-01

    Monitoring and modeling tools may improve irrigation strategies in precision agriculture. We used non-invasive soil moisture monitoring, a crop growth and a soil hydrological model to predict soil-water content fluctuations and crop yield in a heterogeneous sandy grassland soil under supplementary irrigation. The sensitivity of the model to hydraulic parameters, water stress, crop yield and lower boundary conditions was assessed. Free drainage and incremental constant head conditions was implemented in a lower boundary sensitivity analysis. A time-dependent sensitivity analysis showed that changes in soil water content are mainly affected by the soil saturated hydraulic conductivity Ks and the Mualem-van Genuchten retention curve shape parameters n and α. Results further showed that different parameter optimization strategies (two-, three-, four- or six-parameter optimizations) did not affect the calculated water stress and water content as significantly as does the bottom boundary. For this case, a two-parameter scenario, where Ks was optimized for each layer under the condition of a constant groundwater depth at 135-140 cm, performed best. A larger yield reduction, and a larger number and longer duration of stress conditions occurred in the free drainage condition as compared to constant boundary conditions. Numerical results showed that optimal irrigation scheduling using the aforementioned water stress calculations can save up to 12-22 % irrigation water as compared to the current irrigation regime. This resulted in a yield increase of 4.5-6.5 %, simulated by crop growth model.

  11. Specific microbial gene abundances and soil parameters contribute to C, N, and greenhouse gas process rates after land use change in Southern Amazonian Soils.

    PubMed

    Lammel, Daniel R; Feigl, Brigitte J; Cerri, Carlos C; Nüsslein, Klaus

    2015-01-01

    Ecological processes regulating soil carbon (C) and nitrogen (N) cycles are still poorly understood, especially in the world's largest agricultural frontier in Southern Amazonia. We analyzed soil parameters in samples from pristine rainforest and after land use change to pasture and crop fields, and correlated them with abundance of functional and phylogenetic marker genes (amoA, nirK, nirS, norB, nosZ, nifH, mcrA, pmoA, and 16S/18S rRNA). Additionally, we integrated these parameters using path analysis and multiple regressions. Following forest removal, concentrations of soil C and N declined, and pH and nutrient levels increased, which influenced microbial abundances and biogeochemical processes. A seasonal trend was observed, suggesting that abundances of microbial groups were restored to near native levels after the dry winter fallow. Integration of the marker gene abundances with soil parameters using path analysis and multiple regressions provided good predictions of biogeochemical processes, such as the fluxes of NO3, N2O, CO2, and CH4. In the wet season, agricultural soil showed the highest abundance of nitrifiers (amoA) and Archaea, however, forest soils showed the highest abundances of denitrifiers (nirK, nosZ) and high N, which correlated with increased N2O emissions. Methanogens (mcrA) and methanotrophs (pmoA) were more abundant in forest soil, but methane flux was highest in pasture sites, which was related to soil compaction. Rather than analyzing direct correlations, the data integration using multivariate tools provided a better overview of biogeochemical processes. Overall, in the wet season, land use change from forest to agriculture reduced the abundance of different functional microbial groups related to the soil C and N cycles; integrating the gene abundance data and soil parameters provided a comprehensive overview of these interactions. Path analysis and multiple regressions addressed the need for more comprehensive approaches to improve our

  12. Adequacy of transport parameters obtained in soil column experiments for selected chemicals

    NASA Astrophysics Data System (ADS)

    Raymundo-Raymundo, E.; Nikolskii, Yu. N.; Guber, A. K.; Landeros-Sanchez, C.

    2012-07-01

    The transport parameters were determined for the 18O isotope (in the form of H2 18O), the Br- ion, and atrazine in intact columns of allophanic Andosol (Mexico State, Mexico). A one-dimensional model for the convective-dispersive transport of chemicals with account for the decomposition and equilibrium adsorption (HYDRUS-1D), which is widely applied for assessing the risk of the chemical and bacterial contamination of natural waters, was used. The model parameters were obtained by solving the inverse problem on the basis of laboratory experiments on the transport of the 18O isotope, the Br- ion, and atrazine in intact soil columns at a fixed filtration velocity. The hydrodynamic dispersion parameters determined for the 18O and Br- ions in one column were of the same order of magnitude, and those for atrazine were higher by 3-4 times. The obtained parameters were used to calculate the transport of these substances in another column with different values of the water content and filtration velocity. The transport process was adequately described only for the 18O isotope. In the case of the Br- ion, the model significantly underestimated the transport velocity; for atrazine, its peak concentration in the column was overestimated. The column study of the transport of the three chemical compounds showed that transport parameters could not be reliably predicted from the results of a single experiment, even when several compounds were used in this experiment.

  13. Effects of long-term use of different farming systems on some physical, chemical and microbiological parameters of soil quality

    NASA Astrophysics Data System (ADS)

    Gajda, Anna M.; Czyż, Ewa A.; Dexter, Anthony R.

    2016-04-01

    The aim of this study was to compare the effects of different farming systems (organic, integrated, conventional and monoculture) on some soil properties as: bulk density, contents of readily-dispersible clay, organic matter and particulate organic matter, and enzymatic activity measured in terms of the intensity of fluorescein diacetate hydrolysis. Soil under permanent grass was used as a control. The study was conducted on the 20 years lasting field experiment. Samples of Haplic Luvisol soil were collected twice a year on fields under winter wheat from the layers of 0-5, 5-10, 15-20, and 30-35 cm. Within arable soils the soil under organic farming contained the greatest amount of organic matter, which influenced strongly the readily-dispersible clay content, especially in the layer of 5-20 cm. The readily-dispersible clay content in soil under organic farming was 3 times lower, as compared to the conventional and monoculture farming. The highest contents of particulate organic matter 6.2 and 3.5 mg g-1 air dry soil, on average were measured in the 0-5 cm layer of control soil and soil under organic farming, respectively. Also, soil under organic farming and control soil from the depth of 0-5 cm showed 2-2.5 times greater activity of microorganisms in fluorescein diacetate hydrolysis than soil under conventional and monoculture farming. Increase of concentration of organic matter in soil under organic farming decreased soil bulk density. Statistical analysis showed significant correlations between studied parameters of soil quality and confirmed their effectiveness as indicators of disturbances in soil environment.

  14. Reflectance of vegetation, soil, and water. [effects of measurable plant parameters on multispectral signal variations

    NASA Technical Reports Server (NTRS)

    Wiegand, C. L. (Principal Investigator)

    1974-01-01

    The author has identified the following significant results. Reflectance of crop residues, that are important in reducing wind and water erosion, was more often different from bare soil in band 4 than in bands 5, 6, or 7. The plant parameters leaf area index, plant population, plant cover, and plant height explained 95.9 percent of the variation in band 7 (reflective infrared) digital counts for cotton and 78.2 percent of the variation in digital counts for the combined crops sorghum and corn; hence, measurable plant parameters explain most of the signal variation recorded for corpland. Leaf area index and plant population are both highly correlated with crop yields; since plant population can be readily measured (or possibly inferred from seeding rates), it is useful measurement for calibrating ERTS-type MSS digital data in terms of yield.

  15. How do alternative root water uptake models affect the inverse estimation of soil hydraulic parameters and the prediction of evapotranspiration?

    NASA Astrophysics Data System (ADS)

    Gayler, Sebastian; Salima-Sultana, Daisy; Selle, Benny; Ingwersen, Joachim; Wizemann, Hans-Dieter; Högy, Petra; Streck, Thilo

    2016-04-01

    Soil water extraction by roots affects the dynamics and distribution of soil moisture and controls transpiration, which influences soil-vegetation-atmosphere feedback processes. Consequently, root water uptake requires close attention when predicting water fluxes across the land surface, e.g., in agricultural crop models or in land surface schemes of weather and climate models. The key parameters for a successful simultaneous simulation of soil moisture dynamics and evapotranspiration in Richards equation-based models are the soil hydraulic parameters, which describe the shapes of the soil water retention curve and the soil hydraulic conductivity curve. As measurements of these parameters are expensive and their estimation from basic soil data via pedotransfer functions is rather inaccurate, the values of the soil hydraulic parameters are frequently inversely estimated by fitting the model to measured time series of soil water content and evapotranspiration. It is common to simulate root water uptake and transpiration by simple stress functions, which describe from which soil layer water is absorbed by roots and predict when total crop transpiration is decreased in case of soil water limitations. As for most of the biogeophysical processes simulated in crop and land surface models, there exist several alternative functional relationships for simulating root water uptake and there is no clear reason for preferring one process representation over another. The error associated with alternative representations of root water uptake, however, contributes to structural model uncertainty and the choice of the root water uptake model may have a significant impact on the values of the soil hydraulic parameters estimated inversely. In this study, we use the agroecosystem model system Expert-N to simulate soil moisture dynamics and evapotranspiration at three agricultural field sites located in two contrasting regions in Southwest Germany (Kraichgau, Swabian Alb). The Richards

  16. The Influence of Meteorological Parameters and Other Factors on Soil Radon Dynamics

    NASA Astrophysics Data System (ADS)

    Yakovleva, V. S.; Nagorsky, P. M.; Kondratyeva, A. G.; Mishina, N. V.

    2016-08-01

    The paper presents the results of the research in the degree of the effect of space weather meteorological parameters and factors on the dynamics of soil radon levels and α- and β-radiation flux densities in a seismically passive region. The cross-correlation analysis showed a significant correlation of β-radiation flux density with temperature in summer, and no correlation in winter. A significant relation between α- and β-radiation flux densities and pressure within the intra-annual range was not observed. The investigation of the high-intensity precipitation effect on radon volumetric activity and α- and β-radiation flux densities showed their abnormal increase. The dependence of the anomaly duration on the depth was revealed. The abnormal jumps in α- and β-radiation flux densities data series occur in the snow-melting periods as well. Low-intensity precipitations significantly violate the standard "diurnal variations" of α- and β-radiation soil fluxes and radon volumetric activity. Fourier analysis showed the diurnal (24 hours) and semidiurnal (12 hours) harmonics for the observed radiation values at a depth of 0.5 m. The obtained results can be used for interpretation of the data on the soil radon monitoring in order to predict earthquakes, etc.

  17. Sorption of selenate on soils and pure phases: kinetic parameters and stabilisation.

    PubMed

    Loffredo, N; Mounier, S; Thiry, Y; Coppin, F

    2011-09-01

    This study was conducted to identify the principle selenate carrier phases for two selected soils, by comparing their reactivity with selenate to that of pure phases of the solids. Silica, calcium carbonate, aluminium hydroxide, goethite, bentonite and humic acid were selected as the main soil carrier phases. Comparisons were made first on the parameter values obtained with the best fit of a kinetic sorption model which can discriminate instantaneous sorption from kinetically limited sorption. Then comparisons were made of the ability for each solid to stabilise selenate by measuring the ratio of the partition coefficient for sorption (Kd(sorption)) over that of the desorption (Kd(desorption)). Kinetics and stabilisation were used to help elucidate the nature of interactions with the test solid phases for a large range of selenate concentrations. The experiments were conducted over 165 h in batch reactors, the solid being isolated from the solution by dialysis tubing, at two pH (5.4 and 8) and three selenate concentrations (1 × 10(-3), 1 × 10(-6) and 1 × 10(-8) mol L(-1)). The results obtained showed that only aluminium hydroxide can sorb selenate throughout the studied pH range (pH 5.4 to 8.0). The sorption capacity on this mineral was high (Kd(sorption) > 100 to 1 × 10(4) L kg(-1)) and the selenate was mainly stabilized by the formation of inner sphere complexes. The sorption on goethite occurred at pH 5.4 (Kd(sorption) 52 L kg(-1)), mainly as outer sphere complexes, and was null at pH 8. On silica, a weak sorption was observed only at pH 5.4 and at 165 h (Kd(sorption) 4 L kg(-1)). On bentonite, calcium carbonate and humic acid no significant sorption was observed. Concerning the two soils studied, different behaviours were observed for selenate. For soil Ro (pH 5.4), Kd(sorption) was low (8 L kg(-1)) compared to soil Bu (pH 8) (70 L kg(-1)). The sorption behaviour of selenate on soil Ro was mainly due to outer sphere complexes, as for

  18. Parameter Measurement and Estimation at Variable Scales: Example of Soil Temperature in Complex Terrain

    NASA Astrophysics Data System (ADS)

    Seyfried, M. S.

    2015-12-01

    The issue of matching measurement scale to application scale is long standing and frequently revisited with advances in instrumentation and computing power. In the past we have emphasized the importance of understanding the dominant processes and amount and nature of parameter variability when addressing these issues. Landscape-scale distribution of carbon and carbon fluxes is a primary focus of the Reynolds Creek Critical Zone Observatory (RC CZO). Soil temperature (Ts) is a critical parameter of generally unknown variability. Estimates of Ts are often based on air temperature (Ta), but it is understood that other factors control Ts, especially in complex terrain, where solar radiation may be a major driver. Data were collected at the Reynolds Creek Experimental Watershed (RCEW), which is 240 km2 in extent and covers a 1000 m elevation range. We used spatially extensive Ts data to evaluate correlations with Ta (915 m elevation gradient) on aspect neutral sites with similar vegetative cover. Effects of complex terrain were evaluated using a combination of fixed point measurements, fiber optic distributed temperature sensing and periodic, spatially distributed point measurements. We found that Ts over the elevation gradient followed Ta closely. However, within small subwatersheds with uniform Ta, Ts may be extremely variable, with a standard deviation of 8° C. This was strongly related to topographically associated land surface units (LSU's) and highly seasonal. Within LSU variability was generally low while there were seasonally significant differences between LSU's. The mean annual soil temperature difference between LSU's was greater than that associated with the 915 m elevation gradient. The seasonality of Ts variability was not directly related to solar radiation effects but rather to variations in cover. Scaling Ts requires high resolution accounting of topography in this environment. Spatial patterns of soil carbon at the RCEW are consistent with this.

  19. Uncertainty reduction of gravity and magnetic inversion through the integration of petrophysical constraints and geological data

    NASA Astrophysics Data System (ADS)

    Giraud, Jérémie; Jessell, Mark; Lindsay, Mark; Martin, Roland; Pakyuz-Charrier, Evren; Ogarko, Vitaliy

    2016-04-01

    We introduce and test a workflow that integrates petrophysical constraints and geological data in geophysical inversion to decrease the uncertainty and non-uniqueness of the results. We show that the integration of geological information and petrophysical constraints in geophysical inversion can improve inversion results in terms of both uncertainty reduction and resolution. This workflow uses statistical petrophysical properties to constrain the values retrieved by the geophysical inversion and geological prior information to decrease the effect of non-uniqueness. Surface geological data are used to generate geological models as a source of geometrical prior information. Petrophysical measurements are used to derive the statistical laws used for the petrophysical constraints. We integrate the different sources of information in a Bayesian framework, which will take into account these states of information. This permits us to quantify the posterior state of knowledge, the reduction of the uncertainty and to calculate the influence of prior information. To quantify the influence of petrophysical constraints and geological data we compare results obtained with several levels of constraints. We start by inverting data without petrophysical constraints and geological prior information. Then, we add petrophysical constraints before using geological prior information. The results of the inversion are characterized using fixed-point statistics. Various indicators such as model and data misfits, resolution matrices and statistical fit to the petrophysical data are calculated. The resolution matrices are used to plot sensitivity maps. We calculate the posterior covariance matrices to estimate the uncertainty of the model. This workflow was first tested using very simple synthetic datasets before using a subset of the Mansfield area data (Victoria, Australia). The geological model is derived from geological field data. We simulate petrophysical properties based on field

  20. Sensitivity of water stress in a two-layered sandy grassland soil to variations in groundwater depth and soil hydraulic parameters

    NASA Astrophysics Data System (ADS)

    Rezaei, M.; Seuntjens, P.; Joris, I.; Boënne, W.; Van Hoey, S.; Campling, P.; Cornelis, W. M.

    2016-01-01

    Monitoring and modelling tools may improve irrigation strategies in precision agriculture. We used non-invasive soil moisture monitoring, a crop growth and a soil hydrological model to predict soil water content fluctuations and crop yield in a heterogeneous sandy grassland soil under supplementary irrigation. The sensitivity of the soil hydrological model to hydraulic parameters, water stress, crop yield and lower boundary conditions was assessed after integrating models. Free drainage and incremental constant head conditions were implemented in a lower boundary sensitivity analysis. A time-dependent sensitivity analysis of the hydraulic parameters showed that changes in soil water content are mainly affected by the soil saturated hydraulic conductivity Ks and the Mualem-van Genuchten retention curve shape parameters n and α. Results further showed that different parameter optimization strategies (two-, three-, four- or six-parameter optimizations) did not affect the calculated water stress and water content as significantly as does the bottom boundary. In this case, a two-parameter scenario, where Ks was optimized for each layer under the condition of a constant groundwater depth at 135-140 cm, performed best. A larger yield reduction, and a larger number and longer duration of stress conditions occurred in the free drainage condition as compared to constant boundary conditions. Numerical results showed that optimal irrigation scheduling using the aforementioned water stress calculations can save up to 12-22 % irrigation water as compared to the current irrigation regime. This resulted in a yield increase of 4.5-6.5 %, simulated by the crop growth model.

  1. Hydrogeological, petrophysical and hydrogeochemical characteristics of the groundwater aquifers east of Wadi El-Natrun, Egypt

    NASA Astrophysics Data System (ADS)

    Salem, Zenhom E.; El-Bayumy, Dina A.

    2016-06-01

    The studied water-bearing formations in the investigated area are the Quaternary and the Miocene aquifers. The groundwater movement takes a direction from the eastern and northern directions where the surface water sources are located to the western and southern directions. By comparing the water level data of 1960 and 2010, up to 25 m drawdown was noticed in the southern part due to excessive pumping. On the other hand, water level rising was observed in the same period reaching up to 10 m in the northwestern part due to seepage from the irrigation channel. Petrophysical properties of the studied aquifers were estimated from well logs. The formation water resistivity (Rw) averages 15.2 ohm m whereas the formation factor (F) averages 5.1. The averages of the total porosity, the effective porosity and permeability are 36.5%, 33.1% and 1126.3 mdarcy, respectively. In addition, the gamma ray logs were used to estimate the volume share of shale which showed an average value reached about 34.6%. Total porosity, effective porosity and permeability showed an increasing trend to the northwestern direction where the recharge area is located. The concentrations of TDS and the dissolved elements are higher in the shallow groundwater compared to the deeper one, which could be related to soil salinity and evaporation processes. Ion exchange, water-rock interaction and evaporation processes are the main geochemical processes affecting the chemistry of the studied groundwater. Sodium chloride/bicarbonate types are the most common chemical types in the study area. Most of the water samples are of old meteoric origin (Na2SO4 type) and old marine origin (MgCl2 type). On the basis of SAR and EC values it is concluded that most of the groundwater samples are suitable for irrigation purposes.

  2. Hydraulic and thermal soil Parameter combined with TEM data at quaternary coastal regions

    NASA Astrophysics Data System (ADS)

    Grabowski, Ima; Kirsch, Reinhard; Scheer, Wolfgang

    2014-05-01

    In order to generate a more efficient method of planning and dimensioning small- and medium sized geothermal power plants at quaternary subsurface a basic approach has been attempted. Within the EU-project CLIWAT, the coastal region of Denmark, Germany, Netherlands and Belgium has been investigated and air borne electro magnetic data was collected. In this work the regional focus was put on the isle of Föhr. To describe the subsurface with relevant parameters one need the information from drillings and geophysical well logging data. The approach to minimize costs and use existing data from state agencies led the investigation to the combination of specific electrical resistivity data and hydraulic and thermal conductivity. We worked out a basic soil/hydraulic conductivity statistic for the isle of Föhr by gathering all well logging data from the island and sorted the existing soil materials to associated kf -values. We combined specific electrical resistivity with hydraulic soil properties to generate thermal conductivity values by extracting porosity. Until now we generated a set of rough data for kf - values and thermal conductivity. The air borne TEM data sets are reliable up to 150 m below surface, depending on the conductivity of the layers. So we can suppose the same for the differentiated parameters. Since this is a very rough statistic of kf -values, further more investigation has to be made. Although the close connection to each area of investigation either over existing logging data or laboratory soil property values will remain necessary. Literature: Ahmed S, de Marsily G, Talbot A (1988): Combined Use of Hydraulic and Electrical Properties of an Aquifer in a Geostatistical Estimation of Transmissivity. - Groundwater, vol. 26 (1) Burschil T, Scheer W, Wiederhold H, Kirsch R (2012): Groundwater situation on a glacially affected barrier island. Submitted to Hydrology and Earth System Sciences - an Interactive Open Access Journal of the European

  3. Diphenylarsinic acid contaminated soil remediation by titanium dioxide (P25) photocatalysis: Degradation pathway, optimization of operating parameters and effects of soil properties.

    PubMed

    Wang, A-nan; Teng, Ying; Hu, Xue-feng; Wu, Long-hua; Huang, Yu-juan; Luo, Yong-ming; Christie, Peter

    2016-01-15

    Diphenylarsinic acid (DPAA) is formed during the leakage of arsenic chemical weapons in sites and poses a high risk to biota. However, remediation methods for DPAA contaminated soils are rare. Here, the photocatalytic oxidation (PCO) process by nano-sized titanium dioxide (TiO2) was applied to degrade DPAA in soil. The degradation pathway was firstly studied, and arsenate was identified as the final product. Then, an orthogonal array experimental design of L9(3)(4), only 9 experiments were needed, instead of 81 experiments in a conventional one-factor-at-a-time, was used to optimize the operational parameters soil:water ratio, TiO2 dosage, irradiation time and light intensity to increase DPAA removal efficiency. Soil:water ratio was found to have a more significant effect on DPAA removal efficiency than other properties. The optimum conditions to treat 4 g soil with a DPAA concentration of 20 mg kg(-1) were found to be a 1:10 soil: water ratio, 40 mW cm(-2) light intensity, 5% TiO2 in soil, and a 3-hour irradiation time, with a removal efficiency of up to 82.7%. Furthermore, this method (except for a change in irradiation time from 3 to 1.5h) was validated in nine different soils and the removal efficiencies ranged from 57.0 to 78.6%. Removal efficiencies were found to be negatively correlated with soil electrical conductivity, organic matter content, pH and total phosphorus content. Finally, coupled with electron spin resonance (ESR) measurement, these soil properties affected the generation of OH• by TiO2 in soil slurry. This study suggests that TiO2 photocatalytic oxidation is a promising treatment for removing DPAA from soil.

  4. The spatiotemporal characteristics of soil physio-chemical parameters and their influence on cotton growth under mulched drip irrigation

    NASA Astrophysics Data System (ADS)

    Hu, H.; Tian, F.; Zhang, Z.; Hu, H.

    2013-12-01

    The spatiotemporal characteristics of the physio-chemical parameters of soil and their impacts on crop growth are the key issues affecting precision agriculture. However, quantitative research in cotton fields under mulched drip irrigation is rare. One hundred experimental plots (6 m× 6 m) were set up for the above purpose in an agricultural experimental field in Xinjiang Uygur Autonomous Region of China. Soil samples were collected to measure the soil texture, moisture and salinity at depths of 5, 10, 20, 30, 50 and 80 cm in the near-tape zone and the inter-film zone in each experimental plot in March, April, June and September of 2012. The number and height of the cotton plants in June and the yield of cotton in September were also surveyed in 3 sample units (75 cm × 75 cm) in each experimental plot. The results indicate that the soil composition of clay and silt was highest at a soil depth of 5 to 20 cm due to the cultivation practices, and the Cv (coefficient of variation) values of soil texture increased with depth. The spring flush led to an 8% decrease in soil salinity and reduced the Cv values of soil salinity, soil moisture and soil texture. The Cv values of soil salinity and soil moisture increased as mulched drip irrigation was applied. The Cv values of soil salinity and moisture under the near tape zone were higher than under the interfilm zone; the difference was up to twofold in September. The validity of a theoretical semivariogram model of soil moisture is greater than that of texture, soil salinity and crop trait when comparing the estimation of the theoretical semivariogram with measured values. The influence of soil physiochemical characteristics on the number of cotton plants is largest in April, and their influence on the height of cotton plants is greatest in June. However, the influence of soil physiochemical characteristics on cotton yield is smaller than that on cotton number and height in April and June. The soil salt under the near tape

  5. Influence of rhizosphere microbial ecophysiological parameters from different plant species on butachlor degradation in a riparian soil.

    PubMed

    Yang, Changming; Wang, Mengmeng; Li, Jianhua

    2012-01-01

    Biogeochemical processes in riparian zones regulate contaminant movement to receiving waters and often mitigate the impact of upland sources of contaminants on water quality. However, little research has been reported on the microbial process and degradation potential of herbicide in a riparian soil. Field sampling and incubation experiments were conducted to investigate differences in microbial parameters and butachlor degradation in the riparian soil from four plant communities in Chongming Island, China. The results suggested that the rhizosphere soil had significantly higher total organic C and water-soluble organic C relative to the nonrhizosphere soil. Differences in rhizosphere microbial community size and physiological parameters among vegetation types were significant. The rhizosphere soil from the mixed community of Phragmites australis and Acorus calamus had the highest microbial biomass and biochemical activity, followed by A. calamus, P. australis and Zizania aquatica. Microbial ATP, dehydrogenase activity (DHA), and basal soil respiration (BSR) in the rhizosphere of the mixed community of P. australis and A. calamus were 58, 72, and 62% higher, respectively, than in the pure P. australis community. Compared with the rhizosphere soil of the pure plant communities, the mixed community of P. australis and A. calamus displayed a significantly greater degradation rate of butachlor in the rhizosphere soil. Residual butachlor concentrations in rhizosphere soil of the mixed community of P. australis and A. calamus and were 48, 63, and 68% lower than three pure plant communities, respectively. Butachlor degradation rates were positively correlated to microbial ATP, DHA, and BSR, indicating that these microbial parameters may be useful in assessing butachlor degradation potential in the riparian soil.

  6. Characterization of the Qishn sandstone reservoir, Masila Basin-Yemen, using an integrated petrophysical and seismic structural approach

    NASA Astrophysics Data System (ADS)

    Lashin, Aref; Marta, Ebrahim Bin; Khamis, Mohamed

    2016-03-01

    This study presents an integrated petrophysical and seismic structural analysis that is carried out to evaluate the reservoir properties of Qishn sandstone as well as the entrapment style of the hydrocarbons at Sharyoof field, Sayun-Masila Basin that is located at the east central of Yemen. The reservoir rocks are dominated by clean porous and permeable sandstones zones usually intercalated with some clay stone interbeds. As identified from well logs, Qishn sandstone is classified into subunits (S1A, S1B, S1C and S2) with different reservoir characteristics and hydrocarbon potentiality. A number of qualitative and quantitative well logging analyses are used to characterize the different subunits of the Qishn reservoir and identify its hydrocarbon potentiality. Dia-porosity, M-N, Pickett, Buckles plots, petrophysical analogs and lateral distribution maps are used in the analysis. Shale volume, lithology, porosity, and fluid saturation are among the most important deduced parameters. The analysis revealed that S1A and S1C are the main hydrocarbon-bearing units. More specifically, S1A unit is the best, as it attains the most prolific hydrocarbon saturations (oil saturation "SH″ up to 65) and reservoir characteristics. An average petrophysical ranges of 4-21%, 16-23%, 11-19%, 0-65%, are detected for S1A unit, regarding shale volume, total and effective porosity, and hydrocarbon saturation, respectively. Meanwhile, S1B unit exhibits less reservoir characteristics (Vsh>30%, ϕEff<15% and SH< 15%). The lateral distribution maps revealed that most of the hydrocarbons (for S1A and S1C units) are indicated at the middle of the study area as NE-SW oriented closures. The analysis and interpretation of seismic data had clarified that the structure of study area is represented by a big middle horst bounded by a group of step-like normal faults at the extreme boundaries (faulted anticlinal-structure). In conclusion, the entrapment of the encountered hydrocarbon at Sharyoof oil

  7. The effect on performance and biochemical parameters when soil was added to aflatoxin-contaminated poultry rations.

    PubMed

    Madden, U A; Stahr, H M; Stino, F K

    1999-08-01

    The effects of silty clay loam soil on the performance and biochemical parameters of chicks were investigated when the soil was added to aflatoxin B1 (AFB1)-contaminated diets. One hundred 14-d-old White Leghorn chicks were fed a control ration (clean corn), a low aflatoxin-contaminated ration (120 ng AFB1/g), a high aflatoxin-contaminated ration (700 ng AFB1/g), or high aflatoxin-contaminated rations (700 ng AFB1/g) +10% or 25% soil. Body weight, feed consumption and blood samples were monitored weekly. Decreased feed consumption, body weight gain and efficiency of feed utilization, increased SGOT and LDH activities, and cholesterol and triglyceride concentrations, and decreased uric acid concentrations and ALP activity were observed in the chicks fed the high aflatoxin-contaminated ration without soil. Hepatomegaly was prominent in chicks fed the high aflatoxin-contaminated ration without soil, and some livers had extensive hepatocyte vacuolation, hepatocellular swelling, fatty change and hydropic degeneration, and stained positive for fat accumulation. Addition of soil reduced the detrimental effects of AFB1 for some parameters, although the reduction was less when 10% soil was fed compared with the 25% soil feeding. PMID:10434374

  8. A sensitivity analysis of hazardous waste disposal site climatic and soil design parameters using HELP3

    SciTech Connect

    Adelman, D.D.; Stansbury, J.

    1997-12-31

    The Resource Conservation and Recovery Act (RCRA) Subtitle C, Comprehensive Environmental Response, Compensation, And Liability Act (CERCLA), and subsequent amendments have formed a comprehensive framework to deal with hazardous wastes on the national level. Key to this waste management is guidance on design (e.g., cover and bottom leachate control systems) of hazardous waste landfills. The objective of this research was to investigate the sensitivity of leachate volume at hazardous waste disposal sites to climatic, soil cover, and vegetative cover (Leaf Area Index) conditions. The computer model HELP3 which has the capability to simulate double bottom liner systems as called for in hazardous waste disposal sites was used in the analysis. HELP3 was used to model 54 combinations of climatic conditions, disposal site soil surface curve numbers, and leaf area index values to investigate how sensitive disposal site leachate volume was to these three variables. Results showed that leachate volume from the bottom double liner system was not sensitive to these parameters. However, the cover liner system leachate volume was quite sensitive to climatic conditions and less sensitive to Leaf Area Index and curve number values. Since humid locations had considerably more cover liner system leachate volume than and locations, different design standards may be appropriate for humid conditions than for and conditions.

  9. Massively Parallel Computation of Soil Surface Roughness Parameters on A Fermi GPU

    NASA Astrophysics Data System (ADS)

    Li, Xiaojie; Song, Changhe

    2016-06-01

    Surface roughness is description of the surface micro topography of randomness or irregular. The standard deviation of surface height and the surface correlation length describe the statistical variation for the random component of a surface height relative to a reference surface. When the number of data points is large, calculation of surface roughness parameters is time-consuming. With the advent of Graphics Processing Unit (GPU) architectures, inherently parallel problem can be effectively solved using GPUs. In this paper we propose a GPU-based massively parallel computing method for 2D bare soil surface roughness estimation. This method was applied to the data collected by the surface roughness tester based on the laser triangulation principle during the field experiment in April 2012. The total number of data points was 52,040. It took 47 seconds on a Fermi GTX 590 GPU whereas its serial CPU version took 5422 seconds, leading to a significant 115x speedup.

  10. Small scale variability of soil parameters in different land uses on the southern slopes of Mount Kilimanjaro

    NASA Astrophysics Data System (ADS)

    Bogner, Christina; Kühnel, Anna; Hepp, Johannes; Huwe, Bernd

    2016-04-01

    The Kilimanjaro region in Tanzania constitutes a particularity compared to other areas in the country. Because enough water is available the population grows rapidly and large areas are converted from natural ecosystems to agricultural areas. Therefore, the southern slopes of Mt. Kilimanjaro encompass a complex mosaic of different land uses like coffee plantations, maize, agroforestry or natural savannah. Coffee is an important cash crop in the region and is owned mostly by large companies. In contrast, the agroforestry is a traditional way of agriculture and has been sustained by the Chagga tribe for centuries. These so called homegardens are organised as multi-level systems and contain a mixture of different crops. Correlations in soil and vegetation data may serve as indicators for crop and management impacts associated to different types of land use. We hypothesize that Chagga homegardens, for example, show a more pronounced spatial autocorrelation compared to coffee plantations due to manifold above and belowground crop structures, whereas the degree of anisotropy is assumed to be higher in the coffee sites due to linear elements in management. Furthermore, we hypothesize that the overall diversity of soil parameters in homegardens on a larger scale is higher, as individual owners manage their field differently, whereas coffee plantation management often follows general rules. From these general hypotheses we derive two specific research questions: a) Are there characteristic differences in the spatial organisation of soil physical parameters of different land uses? b) Is there a recognizable relationship between vegetation structure and soil physical parameters of topsoils? We measured soil physical parameters in the topsoil (bulk density, stone content, texture, soil moisture and penetration resistance). Additionally, we took spectra of soil samples with a portable VIS-NIR spectrometer to determine C and N and measured leaf area index and troughfall as an

  11. Improving the Operability of the Cosmic-ray Neutron Soil Moisture Method: Estimation of Soil Calibration Parameters Using Global Datasets

    NASA Astrophysics Data System (ADS)

    Finkenbiner, C. E.; Avery, W. A.; Franz, T. E.; Munoz-Arriola, F.; Rosolem, R.

    2014-12-01

    Despite its critical importance to global food security, approximately 60% of water used for agriculture is wasted each year through inadequate water conservation, losses in distribution, and inefficient irrigation. Therefore, in order to coordinate a strategy to accomplish the agricultural demands in the future we must maintain a stable global food and water trade while increasing crop yield and efficiency. This research aims to improve the operability of the novel cosmic-ray neutron method used for estimating field scale soil moisture. The sensor works by passively counting the above ground low-energy neutrons which correlates to the amount of water in the measurement volume (a circle with radius of ~300 m and vertical depth of ~30 cm). Because the sensor responds to different forms of water (sources of hydrogen), estimates of background water in the mineral soil and soil organic matter must be accounted in order to minimize measurement error. Here we compared field-scale estimates of soil mineral water and soil organic matter with readily available global datasets. Using the newly compiled 1 km resolution Global Soil Dataset (GSDE), we investigate the correlation between (1) soil mineral water and clay content and (2) in-situ soil organic material. Preliminary results of in-situ samples from forty study sites around the globe suggest the GSDE dataset has sufficiently low bias and uncertainty (~ within 0.01 g/g of water equivalent) to better isolate the soil moisture signal from the neutron count information. Incorporation of this dataset will allow for real-time soil moisture mapping of hundreds of center-pivots using the mobile cosmic-ray sensor without the need of time-consuming in-situ soil sampling. The incorporation of this novel technique for soil moisture management has the potential to increase the efficiency of irrigation water use.

  12. Optimization of hydrological parameters in a Soil-Tree-Atmosphere Continuum model of a large White Fir

    NASA Astrophysics Data System (ADS)

    Rings, J.; Kamai, T.; Mollaei Kandelous, M.; Nasta, P.; Vrugt, J. A.; Hartsough, P. C.; Hopmans, J. W.

    2011-12-01

    We use statistical optimization with a hydrologic model to obtain the van Genuchten parameters of a large White Fir tree in a mid-latitude montane forest ecosystem, located in the King's River Experimental Watershed as part of the Southern Sierra Critical Zone Observatory. The site is instrumented for spatially distributed monitoring of soil water content, matric potential and sap flux. The physical tree is represented in a HYDRUS model that models the interactions betweens soil, tree and atmosphere as a continuum. The soil and tree domains are modeled as variably saturated porous media, while atmospheric forcing taken from a nearby flux tower is used to determine the potential evapotranspiration (ET) and root uptake (RU). Actual ET and RU are modeled by accounting for canopy and root distributions together with matric potential stress in the soil-tree domains. This model is embedded within a Markov Chain Monte Carlo (MCMC) framework using current versions of the DREAM_ZS optimization code. We present results of the parameter optimization for time periods in different seasons, analyze the uncertainty and information content in the different measurement methods and use the optimized parameters to study the influence of soil water stress on the soil-root-tree system.

  13. Hyperspectral Data Processing and Mapping of Soil Parameters: Preliminary Data from Tuscany (Italy)

    NASA Astrophysics Data System (ADS)

    Garfagnoli, F.; Moretti, S.; Catani, F.; Innocenti, L.; Chiarantini, L.

    2010-12-01

    -sensor radiance values, where calibration coefficients and parameters from laboratory measurements are applied to non-georeferred VNIR/SWIR DN values. Then, geocoded products are retrieved for each flight line by using a procedure developed in IDL Language and PARGE (PARametric Geocoding) software. When all compensation parameters are applied to hyperspectral data or to the final thematic map, orthorectified, georeferred and coregistered VNIR to SWIR images or maps are available for GIS application and 3D view. Airborne imagery has to be corrected for the influence of the atmosphere, solar illumination, sensor viewing geometry and terrain geometry information, for the retrieval of inherent surface reflectance properties. Then, different geophysical parameters can be investigated and retrieved by means of inversion algorithms. The experimental fitting of laboratory data on mineral content is used for airborne data inversion, whose results are in agreement with laboratory records, demonstrating the possibility to use this methodology for digital mapping of soil properties.

  14. Spatial effects of aboveground biomass on soil ecological parameters and trace gas fluxes in a savannah ecosystem of Mount Kilimanjaro

    NASA Astrophysics Data System (ADS)

    Becker, Joscha; Gütlein, Adrian; Sierra Cornejo, Natalia; Kiese, Ralf; Hertel, Dietrich; Kuzyakov, Yakov

    2015-04-01

    The savannah biome is a hotspot for biodiversity and wildlife conservation in Africa and recently got in the focus of research on carbon sequestration. Savannah ecosystems are under strong pressure from climate and land-use change, especially around populous areas like the Mt. Kilimanjaro region. Savannah vegetation in this area consists of grassland with isolated trees and is therefore characterized by high spatial variation of canopy cover, aboveground biomass and root structure. Canopy structure is known to affect microclimate, throughfall and evapotranspiration and thereby controls soil moisture conditions. Consequently, the canopy structure is a major regulator for soil ecological parameters and soil-atmospheric trace gas exchange (CO2, N2O, CH4) in water limited environments. The spatial distribution of these parameters and the connection between above and belowground processes are important to understand and predict ecosystem changes and estimate its vulnerability. Our objective was to determine trends and changes of soil parameters and relate their spatial variability to the vegetation structure. We chose three trees from each of the two most dominant species (Acacia nilotica and Balanites aegyptiaca) in our research area. For each tree, we selected transects with nine sampling points of the same relative distances to the stem. Distances were calculated in relation to the crown radius. At these each sampling point a soil core was taken and separated in 0-10 cm and 10-30 cm depth. We measured soil carbon (C) and nitrogen (N) storage, microbial biomass carbon C and N, soil respiration as well as root biomass and -density, soil temperature and soil water content. Each tree was characterized by crown spread, leaf area index and basal area. Preliminary results show that C and N stocks decreased about 50% with depth independently of distance to the tree. Soil water content under the tree crown increased with depth while it decreased under grass cover. Microbial

  15. Adaptive long-term monitoring of soil health in metal phytostabilization: ecological attributes and ecosystem services based on soil microbial parameters.

    PubMed

    Epelde, Lur; Becerril, José M; Alkorta, Itziar; Garbisu, Carlos

    2014-01-01

    Phytostabilization is a promising option for the remediation of metal contaminated soils which requires the implementation of long-term monitoring programs. We here propose to incorporate the paradigm of "adaptive monitoring", which enables monitoring programs to evolve iteratively as new information emerges and research questions change, to metal phytostabilization. Posing good questions that cover the chemical, toxicological and ecological concerns associated to metal contaminated soils is critical for an efficient long-term phytostabilization monitoring program. Regarding the ecological concerns, soil microbial parameters are most valuable indicators of the effectiveness of metal phytostabilization processes in terms of recovery of soil health. We suggest to group soil microbial parameters in higher-level categories such as "ecological attributes" (vigor, organization, stability) or "ecosystem services" in order to facilitate interpretation and, most importantly, to provide long-term phytostabilization monitoring programs with the required stability through time against changes in techniques, methods, interests, etc. that will inevitably occur during the monitoring program. Finally, a Phytostabilization Monitoring Card, based on both ecological attributes and ecosystem services, for soil microbial properties is provided.

  16. Biochemical parameters and bacterial species richness in soils contaminated by sludge-borne metals and remediated with inorganic soil amendments.

    PubMed

    Mench, Michel; Renella, Giancarlo; Gelsomino, Antonio; Landi, Loretta; Nannipieri, Paolo

    2006-11-01

    The effectiveness of two amendments for the in situ remediation of a Cd- and Ni-contaminated soil in the Louis Fargue long-term field experiment was assessed. In April 1995, one replicate plot (S1) was amended with 5% w/w of beringite (B), a coal fly ash (treatment S1+B), and a second plot with 1% w/w zerovalent-Fe iron grit (SS) (treatment S1+SS), with the aim of increasing metal sorption and attenuating metal impacts. Long-term responses of daily respiration rates, microbial biomass, bacterial species richness and the activities of key soil enzymes (acid and alkaline phosphatase, arylsulfatase, beta-glucosidase, urease and protease activities) were studied in relation to soil metal extractability. Seven years after initial amendments, the labile fractions of Cd and Ni in both the S1+B and S1+SS soils were reduced to various extents depending on the metal and fractions considered. The soil microbial biomass and respiration rate were not affected by metal contamination and amendments in the S1+B and S1+SS soils, whereas the activity of different soil enzymes was restored. The SS treatment was more effective in reducing labile pools of Cd and Ni and led to a greater recovery of soil enzyme activities than the B treatment. Bacterial species richness in the S1 soil did not alter with either treatment. It was concluded that monitoring of the composition and activity of the soil microbial community is important in evaluating the effectiveness of soil remediation practices.

  17. Specific microbial gene abundances and soil parameters contribute to C, N, and greenhouse gas process rates after land use change in Southern Amazonian Soils

    PubMed Central

    Lammel, Daniel R.; Feigl, Brigitte J.; Cerri, Carlos C.; Nüsslein, Klaus

    2015-01-01

    Ecological processes regulating soil carbon (C) and nitrogen (N) cycles are still poorly understood, especially in the world’s largest agricultural frontier in Southern Amazonia. We analyzed soil parameters in samples from pristine rainforest and after land use change to pasture and crop fields, and correlated them with abundance of functional and phylogenetic marker genes (amoA, nirK, nirS, norB, nosZ, nifH, mcrA, pmoA, and 16S/18S rRNA). Additionally, we integrated these parameters using path analysis and multiple regressions. Following forest removal, concentrations of soil C and N declined, and pH and nutrient levels increased, which influenced microbial abundances and biogeochemical processes. A seasonal trend was observed, suggesting that abundances of microbial groups were restored to near native levels after the dry winter fallow. Integration of the marker gene abundances with soil parameters using path analysis and multiple regressions provided good predictions of biogeochemical processes, such as the fluxes of NO3, N2O, CO2, and CH4. In the wet season, agricultural soil showed the highest abundance of nitrifiers (amoA) and Archaea, however, forest soils showed the highest abundances of denitrifiers (nirK, nosZ) and high N, which correlated with increased N2O emissions. Methanogens (mcrA) and methanotrophs (pmoA) were more abundant in forest soil, but methane flux was highest in pasture sites, which was related to soil compaction. Rather than analyzing direct correlations, the data integration using multivariate tools provided a better overview of biogeochemical processes. Overall, in the wet season, land use change from forest to agriculture reduced the abundance of different functional microbial groups related to the soil C and N cycles; integrating the gene abundance data and soil parameters provided a comprehensive overview of these interactions. Path analysis and multiple regressions addressed the need for more comprehensive approaches to improve

  18. Specific microbial gene abundances and soil parameters contribute to C, N, and greenhouse gas process rates after land use change in Southern Amazonian Soils.

    PubMed

    Lammel, Daniel R; Feigl, Brigitte J; Cerri, Carlos C; Nüsslein, Klaus

    2015-01-01

    Ecological processes regulating soil carbon (C) and nitrogen (N) cycles are still poorly understood, especially in the world's largest agricultural frontier in Southern Amazonia. We analyzed soil parameters in samples from pristine rainforest and after land use change to pasture and crop fields, and correlated them with abundance of functional and phylogenetic marker genes (amoA, nirK, nirS, norB, nosZ, nifH, mcrA, pmoA, and 16S/18S rRNA). Additionally, we integrated these parameters using path analysis and multiple regressions. Following forest removal, concentrations of soil C and N declined, and pH and nutrient levels increased, which influenced microbial abundances and biogeochemical processes. A seasonal trend was observed, suggesting that abundances of microbial groups were restored to near native levels after the dry winter fallow. Integration of the marker gene abundances with soil parameters using path analysis and multiple regressions provided good predictions of biogeochemical processes, such as the fluxes of NO3, N2O, CO2, and CH4. In the wet season, agricultural soil showed the highest abundance of nitrifiers (amoA) and Archaea, however, forest soils showed the highest abundances of denitrifiers (nirK, nosZ) and high N, which correlated with increased N2O emissions. Methanogens (mcrA) and methanotrophs (pmoA) were more abundant in forest soil, but methane flux was highest in pasture sites, which was related to soil compaction. Rather than analyzing direct correlations, the data integration using multivariate tools provided a better overview of biogeochemical processes. Overall, in the wet season, land use change from forest to agriculture reduced the abundance of different functional microbial groups related to the soil C and N cycles; integrating the gene abundance data and soil parameters provided a comprehensive overview of these interactions. Path analysis and multiple regressions addressed the need for more comprehensive approaches to improve our

  19. Indirect estimation of calibration equation parameters for Sentek Diviner 2000 capacitance probe by means of soil physical properties

    NASA Astrophysics Data System (ADS)

    Rallo, Giovanni; Provenzano, Giuseppe

    2014-05-01

    Measurements of soil water content (SWC) are often used for irrigation scheduling. Accurate monitoring of SWC is necessary, for example, to identify the exact irrigation timing and the amount of water volume to supply according to the crop requirement. The use of capacitance probes, measuring the apparent soil dielectric permittivity, indirectly related to soil water status, have been increasing during the last decade, as proved by the numerous researches carried out to determine, for different soil types, site-specific calibration relationships between SWC and the scaled frequency (SF) measured by the sensor. However, for swelling/shrinking clay soils, there is a lack of knowledge on how the changes of soil bulk density associated to variations of soil water content influence the apparent dielectric permittivity and therefore the sensor calibration relationship, as a consequence of the different contribute that soil, water and air, have on the measure provided by the sensor. The main objectives of the work are i) to determine the site specific calibration equations for a Sentek Diviner 2000 capacitance probe for soils characterized by different texture, ii) to investigate on the effects of soil bulk density and its variability with soil water content, on the calibration equation and iii) to proceed to the indirect estimation of calibration parameters by means of easily-measurable soil physical properties. Experiments were carried out on nine different soils collected from Sicilian irrigated area, characterized by a clay percentage ranging between 9% and 45%. Undisturbed soil samples (25 cm diameter and 25 cm height), allowed to determine, for each soil, the corresponding site-specific calibration equation. On the other hands, samples having the same dimensions, but filled with sieved soil and compacted at two different bulk densities (ρb), were used to investigate on the effects of soil texture and bulk density on the measured SF. On each undisturbed or sieved

  20. Spatially Distributed Estimation of Mesoscale Water Balance Model Parameters using Hydrological Soil Maps

    NASA Astrophysics Data System (ADS)

    Gronz, O.; Casper, M. C.; Gemmar, P.

    2009-04-01

    In mesoscale water balance models, the relevant hydrological processes in runoff generation are abstractly simulated. One aspect of this abstraction is grouping areas to model elements, each of which simulated individually, resulting in a set of model elements. A single element might be homogeneous by means of a certain characteristics, e. g. land use, but it might also be heterogeneous considering a different feature, e. g. slope. Due to this abstraction and grouping, the processes cannot be described in detail by physical laws and thus, parameters to be calibrated will occur in the model's assumptions. Typically, the same value is used for all elements of a catchment, mainly due to the quantity of all possible parameter value configurations. Thus, the spatial distribution of the occurrence of processes and their specific strength, which can be observed in the real catchment, will not be represented by the model. The model might rather represent the mean behavior. As a result, the distribution of water in the model might not match the real system. This strongly limits the applicability of the model and it increases the complexity of calibration. To support a spatial distributed parameterization of a model, new sources of information need to be incorporated. One way of incorporating additional information is the usage of hydrological soil maps, which are available today. They indicate the potentially dominant runoff processes like Horton overland flow, subsurface flow, deep percolation etc. These maps are e. g. generated by artificial neural networks using various different sources like geological maps, digital terrain models and characteristics derived from this model, land use maps etc. An interdisciplinary project has started to integrate these maps in the calibration process. The main aim is to represent the spatial distribution shown by the map in the model. An initial idea is to find parameter prototypes for each of the runoff processes. These parameter

  1. Analysis of physical parameters related with water infiltration in tropical soils located in edges forest in urban areas

    NASA Astrophysics Data System (ADS)

    Márcia Longo, Regina; Cunha, Jessica C. M.; Lammoglia, Rafaella; Mendes, Deborah R.; Mungilioli, Sarah S.; Damame, Desiree B.; Demamboro, Antônio C.; Bettine, Sueli C.; Ribeiro, Admilson I.; Fengler, Felipe H.

    2015-04-01

    A very important factor for water infiltration into the soil in urban forest systems and suffering constant anthropogenic pressures is the analysis of soil compaction where these forests are or will be established. In this context, this work aimed to promote studies on physical parameters related to distribution of pores, compaction and soil biological activity in forest remnants border areas located in urban watersheds in Campinas / SP - Brazil. The Forest of Santa Genebra (22°49'45 "S and 47°06'33" W) has an average altitude of 680m and tropical climate of altitude, has an area of 251 ha and a nine kilometer perimeter. It constitutes 85% of Semideciduos forests and 15% swamp forest. Due to its location close to urban centers, roads and agricultural areas under direct influence of the anthropic means. For the present study analyzes were performed: particle size, soil density, porosity, matters organic, of biopores, and root distribution (primary, secondary and tertiary) and seedlings in 40 points on the perimeter of the forest equidistant 200m remaining edge. The analysis of the results allowed us to observe that areas suffer direct influence of human activities surrounding. With the results set correlations between the different parameters in order to allow a better understanding of the dynamics of water infiltration into the soil under these conditions and the quantity of tertiary roots, biopores and soil density were the best indicator of environmental quality as suffer direct influence of the surrounding areas, especially those near the most urbanized regions. In general, it can be observed that human activities such as deforestation and vehicle traffic, animals and people, promoted soil compaction and consequent changes in water infiltration into the soil in areas of edges of this remnant of these consequences affect direct numerous parameters that directly influence the dynamics of an ecosystem restoration that is now significantly affected by the

  2. [Monitoring and simulation of soil electrical conductivity based on the hyperspectral parameters of cotton (Gossypium hirsutum) functional leaves].

    PubMed

    Zhang, Lei; Tang, Ming-Xing; Zhang, Guo-Wei; Zhou, Zhi-Guo

    2012-03-01

    Taking the salt-tolerant cotton variety CCRI-44 and salt-sensitive cotton variety Sumian 12 as test materials, a two-year pot experiment was conducted at the Pailou experimental station of Nanjing Agricultural University in 2008 and 2009 to study the relationships of soil electrical conductivity (EC) with the spectral reflectance and hyperspectral indices of cotton functional leaves at different growth stages under five simulated salinity levels (0, 0.35%, 0.60%, 0.85%, and 1.00%) of coastal saline soils, and the quantitative monitoring models on the cotton soil EC were established. With increasing salinity level, the cotton functional leaves had an increased spectral reflectance in near-infrared and middle-infrared regions, and the spectral parameter normalized difference spectrum index (NDSI) based on 1350 nm and 2307 nm, i. e., NDSI (R1350, R2307), correlated well to the soil EC. With the NDSI (R1350, R2307) as independent variable, the soil EC monitoring model was constructed as EC = -42.899 NDSI (R1350, R2307) +27.338. Among the derivative spectral parameters, TM5-SWIR was most correlated to soil EC, and thus, the soil EC monitoring model was constructed as EC = 0.0574TM5-SWIR2-2.5928TM5 -SWIR+30.021. The two models with NDSI (R1350, R2307) and TM5-SWIR as the independent variables respectively all had higher prediction precision, with the determination coefficient being 0. 887 and 0. 814 and the root mean square error being 1.09 and 1.29 dS x m(-1), respectively, suggesting that using the hyperspectral parameters NDSI (R1350, R2307) and TM5-SWIR of cotton functional leaves could effectively monitor the soil EC of saline cotton fields.

  3. Estimation of Bare Surface Soil Moisture and Surface Roughness Parameter Using L-Band SAR Image Data

    NASA Technical Reports Server (NTRS)

    Shi, Jian-Cheng; Wang, James; Hsu, Ann Y.; ONeill, Peggy E.; Engman, Edwin T.

    1997-01-01

    An algorithm based on a fit of the single-scattering Integral Equation Method (IEM) was developed to provide estimation of soil moisture and surface roughness parameter (a combination of rms roughness height and surface power spectrum) from quad-polarized synthetic aperture radar (SAR) measurements. This algorithm was applied to a series of measurements acquired at L-band (1.25 GHz) from both AIRSAR (Airborne Synthetic Aperture Radar operated by the Jet Propulsion Laboratory) and SIR-C (Spaceborne Imaging Radar-C) over a well- managed watershed in southwest Oklahoma. Prior to its application for soil moisture inversion, a good agreement was found between the single-scattering IEM simulations and the L band measurements of SIR-C and AIRSAR over a wide range of soil moisture and surface roughness conditions. The sensitivity of soil moisture variation to the co-polarized signals were then examined under the consideration of the calibration accuracy of various components of SAR measurements. It was found that the two co-polarized backscattering coefficients and their combinations would provide the best input to the algorithm for estimation of soil moisture and roughness parameter. Application of the inversion algorithm to the co-polarized measurements of both AIRSAR and SIR-C resulted in estimated values of soil moisture and roughness parameter for bare and short-vegetated fields that compared favorably with those sampled on the ground. The root-mean-square (rms) errors of the comparison were found to be 3.4% and 1.9 dB for soil moisture and surface roughness parameter, respectively.

  4. The benefits of using remotely sensed soil moisture in parameter identification of large-scale hydrological models

    NASA Astrophysics Data System (ADS)

    Karssenberg, D.; Wanders, N.; de Roo, A.; de Jong, S.; Bierkens, M. F.

    2013-12-01

    Large-scale hydrological models are nowadays mostly calibrated using observed discharge. As a result, a large part of the hydrological system that is not directly linked to discharge, in particular the unsaturated zone, remains uncalibrated, or might be modified unrealistically. Soil moisture observations from satellites have the potential to fill this gap, as these provide the closest thing to a direct measurement of the state of the unsaturated zone, and thus are potentially useful in calibrating unsaturated zone model parameters. This is expected to result in a better identification of the complete hydrological system, potentially leading to improved forecasts of the hydrograph as well. Here we evaluate this added value of remotely sensed soil moisture in calibration of large-scale hydrological models by addressing two research questions: 1) Which parameters of hydrological models can be identified by calibration with remotely sensed soil moisture? 2) Does calibration with remotely sensed soil moisture lead to an improved calibration of hydrological models compared to approaches that calibrate only with discharge, such that this leads to improved forecasts of soil moisture content and discharge as well? To answer these questions we use a dual state and parameter ensemble Kalman filter to calibrate the hydrological model LISFLOOD for the Upper Danube area. Calibration is done with discharge and remotely sensed soil moisture acquired by AMSR-E, SMOS and ASCAT. Four scenarios are studied: no calibration (expert knowledge), calibration on discharge, calibration on remote sensing data (three satellites) and calibration on both discharge and remote sensing data. Using a split-sample approach, the model is calibrated for a period of 2 years and validated for the calibrated model parameters on a validation period of 10 years. Results show that calibration with discharge data improves the estimation of groundwater parameters (e.g., groundwater reservoir constant) and

  5. Relationships between nuclear magnetic resonance parameters used to characterize weathering spilled oil and soil toxicity in central Patagonia.

    PubMed

    Ríos, Stella Maris; Barquin, Mercedes; Katusich, Ofelia; Nudelman, Norma

    2014-01-01

    Oil spill in the Central Patagonian zone was studied to evaluate if any relationship exists between the parameters used to characterize weathering spilled oil and soil toxicity for two plant species and to evaluate if the phytotoxicity to local species would be a good index for the soil contamination. Nuclear magnetic resonance (NMR) structural indexes and column chromatography compositional indexes were determined to characterize the oil spill in the soil samples. Bioassays were also carried out using Lactuca sativa L (reference) and Atriplex lampa (native species) as test organisms. Measurements of the total petroleum hydrocarbon (TPH) and the electrical conductivity (EC) of the soil were carried out to evaluate the effect on the bioassays. The principal components analysis of the parameters determined by NMR, compositional indexes, EC, TPH, and toxicology data shows that the first three principal components accounted for the 78% of the total variance (40%, 25%, and 13% for the first, second, and third PC, respectively). A good agreement was found between information obtained by compositional indexes and NMR structural indexes. Soil toxicity increases with the increase of EC and TPH. Other factors, such as, the presence of branched and aromatic hydrocarbons is also significant. The statistical evaluation showed that the Euclidean distances (3D) between the background and each one of the samples might be a better indicator of the soil contamination, compared with chemical criterion of TPH. PMID:25145179

  6. Relationships between nuclear magnetic resonance parameters used to characterize weathering spilled oil and soil toxicity in central Patagonia.

    PubMed

    Ríos, Stella Maris; Barquin, Mercedes; Katusich, Ofelia; Nudelman, Norma

    2014-01-01

    Oil spill in the Central Patagonian zone was studied to evaluate if any relationship exists between the parameters used to characterize weathering spilled oil and soil toxicity for two plant species and to evaluate if the phytotoxicity to local species would be a good index for the soil contamination. Nuclear magnetic resonance (NMR) structural indexes and column chromatography compositional indexes were determined to characterize the oil spill in the soil samples. Bioassays were also carried out using Lactuca sativa L (reference) and Atriplex lampa (native species) as test organisms. Measurements of the total petroleum hydrocarbon (TPH) and the electrical conductivity (EC) of the soil were carried out to evaluate the effect on the bioassays. The principal components analysis of the parameters determined by NMR, compositional indexes, EC, TPH, and toxicology data shows that the first three principal components accounted for the 78% of the total variance (40%, 25%, and 13% for the first, second, and third PC, respectively). A good agreement was found between information obtained by compositional indexes and NMR structural indexes. Soil toxicity increases with the increase of EC and TPH. Other factors, such as, the presence of branched and aromatic hydrocarbons is also significant. The statistical evaluation showed that the Euclidean distances (3D) between the background and each one of the samples might be a better indicator of the soil contamination, compared with chemical criterion of TPH.

  7. Long-term effect on some chemical parameter and microbial diversity in a conifer forest soil

    NASA Astrophysics Data System (ADS)

    Iglesias, T.; Iglesias, M.; Francisco-Álvarez, R.; Ramírez, M.; Fernández-Bermejo, M. C.

    2009-04-01

    Soil microbiota are one of the soil components most affected by wildfires. The data from the present study were obtained from a conifer forest soil at Sierra de Gredos (Ávila, central Spain) twenty years after fire of low-to-moderate intensity. A set of soil characteristics indicated the extent to which the spontaneous recovery of the soil is produced as a result of vegetation regrowth. Ten months after fire a strong increase in soil pH, organic C and N, and exchangeable Ca and K, with respect the control soil. Eighteen years after this fire it was observed a decrease of soil organic C and N, whereas other variables such as pH, exchangeable Ca and K were slightly increased with respect to control soil. Is summe a change in soil microbiota was observed due to wildfire, with a decrease in fungi and bacteria population, Also some changes in microbial community was detected, Key words: Forest Fire, soil microbiology, chemical soil properties

  8. Impact of soil parameter and physical process on reproducibility of hydrological processes by land surface model in semiarid grassland

    NASA Astrophysics Data System (ADS)

    Miyazaki, S.; Yorozu, K.; Asanuma, J.; Kondo, M.; Saito, K.

    2014-12-01

    The land surface model (LSM) takes part in the land-atmosphere interaction on the earth system model for the climate change research. In this study, we evaluated the impact of soil parameters and physical process on reproducibility of hydrological process by LSM Minimal Advanced Treatments of Surface Interaction and RunOff (MATSIRO; Takata et al, 2003, GPC) forced by the meteorological data observed at grassland in semiarid climate in China and Mongolia. The testing of MATSIRO was carried out offline mode over the semiarid grassland sites at Tongyu (44.42 deg. N, 122.87 deg. E, altitude: 184m) in China, Kherlen Bayan Ulaan (KBU; 47.21 deg. N, 108.74 deg. E, altitude: 1235m) and Arvaikheer (46.23 N, 102.82E, altitude: 1,813m) in Mongolia. Although all sites locate semiarid grassland, the climate condition is different among sites, which the annual air temperature and precipitation are 5.7 deg. C and 388mm (Tongyu), 1.2 deg.C and 180mm (KBU), and 0.4 deg. C and 245mm(Arvaikheer). We can evaluate the effect of climate condition on the model performance. Three kinds of experiments have been carried out, which was run with the default parameters (CTL), the observed parameters (OBS) for soil physics and hydrology, and vegetation, and refined MATSIRO with the effect of ice in thermal parameters and unfrozen water below the freezing with same parameters as OBS run (OBSr). The validation data has been provided by CEOP(http://www.ceop.net/) , RAISE(http://raise.suiri.tsukuba.ac.jp/), GAME-AAN (Miyazaki et al., 2004, JGR) for Tongyu, KBU, and Arvaikheer, respectively. The reproducibility of the net radiation, the soil temperature (Ts), and latent heat flux (LE) were well reproduced by OBS and OBSr run. The change of soil physical and hydraulic parameter affected the reproducibility of soil temperature (Ts) and soil moisture (SM) as well as energy flux component especially for the sensible heat flux (H) and soil heat flux (G). The reason for the great improvement on the

  9. Estimation of Bare Surface Soil Moisture and Surface Roughness Parameter Using L-Band SAR Image Data

    NASA Technical Reports Server (NTRS)

    Shi, Jian-Cheng; Wang, James; Hsu, Ann; ONeill, Peggy; Engman, Edwin T.

    1997-01-01

    An algorithm based on a fit of the single-scattering Integral Equation Method (IEM) was developed to provide estimation of soil moisture and surface roughness parameter (a combination of rms roughness height and surface power spectrum) from quasi-polarized synthetic aperture radar (SAR) measurements. This algorithm was applied to a series of measurements acquired at L-band (1.25 GHz) from both AIRSAR (Airborne Synthetic Aperture Radar operated by Jet Propulsion Laboratory) and SIR-C (Spaceborne Imaging Radar-C) over a well-managed watershed in southwest Oklahoma. It was found that the two co-polarized backscattering coefficients and their combinations would provide the best input to the algorithm for estimation of soil moisture and roughness parameter. Application of the inversion algorithm to the co-polarized measurements of both AIRSAR and SIR-C resulted in estimated values of soil moisture and roughness parameter for bare and short-vegetated fields that compared favorably with those sampled on the ground. The root-mean-square (rms) errors of the comparison were found to be 3.4% and 1.9 dB for soil moisture and surface roughness parameter, respectively.

  10. Comparative mapping of soil physical-chemical and structural parameters at field scale to identify zones of enhanced leaching risk.

    PubMed

    Norgaard, Trine; Moldrup, Per; Olsen, Preben; Vendelboe, Anders L; Iversen, Bo V; Greve, Mogens H; Kjaer, Jeanne; de Jonge, Lis W

    2013-01-01

    Preferential flow and particle-facilitated transport through macropores contributes significantly to the transport of strongly sorbing substances such as pesticides and phosphorus. The aim of this study was to perform a field-scale characterization of basic soil physical properties like clay and organic carbon content and investigate whether it was possible to relate these to derived structural parameters such as bulk density and conservative tracer parameters and to actual particle and phosphorus leaching patterns obtained from laboratory leaching experiments. Sixty-five cylindrical soil columns of 20-cm height and 20-cm diameter and bulk soil were sampled from the topsoil in a 15-m × 15-m grid in an agricultural loamy field. Highest clay contents and highest bulk densities were found in the northern part of the field. Leaching experiments with a conservative tracer showed fast 5% tracer arrival times and high tracer recovery percentages from columns sampled from the northern part of the field, and the leached mass of particles and particulate phosphorus was also largest from this area. Strong correlations were obtained between 5% tracer arrival time, tracer recovery, and bulk density, indicating that a few well-aligned and better connected macropores might change the hydraulic conductivity between the macropores and the soil matrix, triggering an onset of preferential flow at lower rain intensities compared with less compacted soil. Overall, a comparison mapping of basic and structural characteristics including soil texture, bulk density, dissolved tracer, particle and phosphorus transport parameters identified the northern one-third of the field as a zone with higher leaching risk. This risk assessment based on parameter mapping from measurements on intact samples was in good agreement with 9 yr of pesticide detections in two horizontal wells and with particle and phosphorus leaching patterns from a distributed, shallow drainage pipe system across the field

  11. Estimating effective roughness parameters of the L-MEB model for soil moisture retrieval from SMAPVEX12 data

    NASA Astrophysics Data System (ADS)

    Martens, Brecht; Lievens, Hans; Colliander, Andreas; Jackson, Thomas; Verhoest, Niko

    2015-04-01

    Despite the continuing efforts to improve existing soil moisture retrieval algorithms, the ability to estimate soil moisture from passive microwave observations is still hampered by problems in accurately modelling the observed microwave signal. Due to the significant influence of both soil roughness and vegetation on the measured brightness temperatures, the parameterisation of these variables is of primary importance for the retrieval of the soil moisture state. Given the complex interference of surface roughness, the effect is usually accounted for using a semi-empirical model such as the one from Wang and Choudhury (1981). Together with a vegetation module, this roughness formulation is implemented in the L-band Microwave Emission from the Biosphere (L-MEB) model (Wigneron et al., 2007), which is also adopted in the operational SMOS Level 2 Soil Moisture retrieval algorithm. However, one of the main issues remains the estimation of the key roughness parameter of the Wang and Choudhury model. Several techniques exists to estimate this principal roughness parameter. Most of them try to estimate an effective roughness parameter, which is not directly linked to the physical roughness of the soil, but which can be considered optimal for the inversion of the radiative transfer model. A number of recent studies concluded that the roughness parameters could be linearly related to the observed surface soil moisture, which could be explained by a dielectric roughness, induced by the heterogeneous distribution of moisture in the soil reservoir. However, this concept has not yet been validated at large scales and/or under vegetated surfaces. This study investigated the behaviour of effective roughness parameters derived from passive remote sensing data using the L-MEB model and developed a simple model for estimating these parameters at large scale. To this end, data from the SMAP Validation Experiment 2012 (SMAPVEX12) conducted in Canada were used. Results indicate that

  12. Soil microbial parameters and luminescent bacteria assays as indicators for in situ bioremediation of TNT-contaminated soils.

    PubMed

    Frische, Tobias; Höper, Heinrich

    2003-01-01

    In situ bioremediation is increasingly being discussed as a useful strategy for cleaning up contaminated soils. Compared to established ex situ procedures, meaningful and reliable approaches for monitoring the remediation processes and their efficiency are of special importance. The subject of this study was the significance of two bioassays for monitoring purposes. The work was performed within the scope of a research project on the in situ bioremediation of topsoil contaminated with 2,4,6-trinitrotoluene (TNT). To evaluate changes within different experimental fields during a 17-month remediation period, the results of soil microbial assays and luminescent bacteria assays were compared with chemical monitoring data. The luminescent bacteria assays showed a significant reduction of the water-soluble soil toxicants in the treated fields. This bioassay proved to be a sensitive screening indicator of toxicity and may effectively aid the ecotoxicological interpretation of chemical monitoring data. Microbial biomass (C(mic)), the metabolic quotient (qCO2), and the ratio of microbial to organic carbon (C(mic)/C(org)) showed a highly significant correlation with total concentrations of TNT in the soil. But, in contrast to luminescent bacteria assays, this approach did not reveal any recovery of the soil at the end of the remediation period. There is clear evidence for persistent adverse effects of chronic TNT contamination on the site-specific microbial community and the local carbon cycle in the soil. The study clearly exhibits the differences between, as well as the complementary value of both bioassay approaches for monitoring short-term and long-term effects of soil contamination and the efficiency of remediation.

  13. Effects of dry bulk density and particle size fraction on gas transport parameters in variably saturated landfill cover soil.

    PubMed

    Wickramarachchi, Praneeth; Kawamoto, Ken; Hamamoto, Shoichiro; Nagamori, Masanao; Moldrup, Per; Komatsu, Toshiko

    2011-12-01

    Landfill sites are emerging in climate change scenarios as a significant source of greenhouse gases. The compacted final soil cover at landfill sites plays a vital role for the emission, fate and transport of landfill gases. This study investigated the effects of dry bulk density, ρ(b), and particle size fraction on the main soil-gas transport parameters - soil-gas diffusivity (D(p)/D(o), ratio of gas diffusion coefficients in soil and free air) and air permeability (k(a)) - under variably-saturated moisture conditions. Soil samples were prepared by three different compaction methods (Standard and Modified Proctor compaction, and hand compaction) with resulting ρ(b) values ranging from 1.40 to 2.10 g cm(-3). Results showed that D(p) and k(a) values for the '+gravel' fraction (<35 mm) became larger than for the '-gravel' fraction (<2mm) under variably-saturated conditions for a given soil-air content (ε), likely due to enhanced gas diffusion and advection through less tortuous, large-pore networks. The effect of dry bulk density on D(p) and k(a) was most pronounced for the '+gravel' fraction. Normalized ratios were introduced for all soil-gas parameters: (i) for gas diffusivity D(p)/D(f), the ratio of measured D(p) to D(p) in total porosity (f), (ii) for air permeability k(a)/k(a)(,pF4.1), the ratio of measured k(a) to k(a) at 1235 kPa matric potential (=pF 4.1), and (iii) for soil-air content, the ratio of soil-air content (ε) to total porosity (f) (air saturation). Based on the normalized parameters, predictive power-law models for D(p)(ε/f) and k(a)(ε/f) models were developed based on a single parameter (water blockage factor M for D(p) and P for k(a)). The water blockage factors, M and P, were found to be linearly correlated to ρ(b) values, and the effects of dry bulk density on D(p) and k(a) for both '+gravel' and '-gravel' fractions were well accounted for by the new models.

  14. Integrated petrophysical and lithofacies studies of lower-middle Miocene reservoirs in Belayim marine oil field, Gulf of Suez, Egypt

    NASA Astrophysics Data System (ADS)

    Ali Ali, El-Khadragy; Emad El Din Abd Elrazik, Eysa; Shebl Azam, Salah; Ahmed Hassan, Saleh

    2016-05-01

    The reservoir parameters (total gross thickness, shale volume, total porosity, effective porosity, water saturation, bulk pore volume, net pay thickness and oil in place indicator) of Kareem and Belayim formations are studied through nine wells and mapped to show the aerial distribution of these parameters. Interpretation of these maps showed that, the best locations of hydrocarbon accumulation in Belayim marine oil field are middle part, northeast and the south west directions for Kareem formation and southwest and northeast directions for Belayim formation. The petrophysical results of Belayim formation were presented in the form of 3D slicing models to exhibit the variation of these parameters in the different directions. Cross plots of Kareem formation were done using neutron, density and sonic logs which is directly influenced by the matrix composition. By using two or three porosity logs reading we determined the porosity and evaluated the matrix characteristics of Kareem formation as it is considered as a good reservoir for oil and gas and mainly composed of sand stone. Finally, facies maps for Kareem and Belayim formations which established using composite logs indicate that, the environment of deposition of Kareem formation was deep marine in the middle and northern parts and shallow in the southern parts of the study area, meanwhile in Belayim formation the environment of deposition was in lagoonal through the deposition of Baba and Feiran members and shallow to deep during the sedimentation of Sidri and Hammam Faraun members.

  15. Global SMOS Soil Moisture Retrievals from The Land Parameter Retrieval Model

    NASA Astrophysics Data System (ADS)

    Schalie, R. van der; Kerr, Y. H.; Wigneron, J. P.; Rodríguez-Fernández, N. J.; Al-Yaari, A.; Jeu, R. A. M. de

    2016-03-01

    A recent study by Van der Schalie et al. (2015) showed good results for applying the Land Parameter Retrieval Model (LPRM) on SMOS observations over southeast Australia and optimizing and evaluating the retrieved soil moisture (θ in m3 m-3) against ground measurements from the OzNet sites. In this study, the LPRM parameterization is globally updated for SMOS against modelled θ from MERRA-Land (MERRA) and ERA-Interim/Land (ERA) over the period of July 2010-December 2010, mainly focusing on two parameters: the single scattering albedo (ω) and the roughness (h). The Pearson's coefficient of correlation (r) increased rapidly when increasing the ω up to 0.12 and reached a steady state from thereon, no significant spatial pattern was found in the estimation of the single scattering albedo, which could be an artifact of the used parameter estimation procedure, and a single value of 0.12 was therefore used globally. The h was defined as a function of θ and varied slightly for the different angle bins, with maximum values of 1.1-1.3 as the angle changes from 42.5° to 57.5°.This resulted in an average r of 0.51 and 0.47, with a bias (m3 m-3) of -0.02 and -0.01 and an unbiased root mean square error (ubrmse in m3 m-3) of 0.054 and 0.056 against MERRA (ascending and descending). For ERA this resulted in an r of 0.61 and 0.53, with a bias of -0.03 and an ubrmse 0.055 and 0.059. The resulting parameterization was then used to run LPRM on SMOS observations over the period of July 2010-December 2013 and evaluated against SMOS Level 3 (L3) θ and available in situ measurements from the International Soil Moisture Network (ISMN). The comparison with L3 shows that the LPRM θ retrievals are very similar, with for the ascending set very high r of over 0.9 in large parts of the globe, with an overall average of 0.85 and the descending set performing less with an average of 0.74, mainly due to the negative r over the Sahara. The mean bias is 0.03, with an ubrmse of 0.038 and 0

  16. Effects of Environmental Parameters on the Formation and Turnover of Acetate by Forest Soils

    PubMed Central

    Kusel, K.; Drake, H. L.

    1995-01-01

    The capacity to form acetate from endogenous matter was a common property of diverse forest soils when incubated under anaerobic conditions. At 15 to 20(deg)C, acetate synthesis occurred without appreciable delay when forest soils were incubated as buffered suspensions or in microcosms at various percentages of their maximum water holding capacity. Rates for acetate formation with soil suspensions ranged from 35 to 220 (mu)g of acetate per g (dry weight) of soil per 24 h, and maximal acetate concentrations obtained in soil suspensions were two- to threefold greater than those obtained with soil microcosms at the average water holding capacity of the soil. Cellobiose degradation in soil suspensions yielded H(inf2) as a transient product. Under anaerobic conditions, supplemental H(inf2) and CO(inf2) were directed towards the acetogenic synthesis of acetate, and enrichments yielded a syringate-H(inf2)-consuming acetogenic consortium. At in situ temperatures, acetate was a relatively stable anaerobic end product; however, extended incubation periods induced acetoclastic methanogenesis and sulfate reduction. Higher mesophilic and thermophilic temperatures greatly enhanced the capacity of soils to form methane. Although methanogenic and sulfate-reducing activities under in situ-relevant conditions were negligible, these findings nonetheless demonstrated the occurrence of methanogens and sulfate-reducing bacteria in these aerated terrestrial soils. In contrast to the protracted stability of acetate under anaerobic conditions at 15 to 20(deg)C with unsupplemented soils, acetate formed by forest soils was rapidly consumed in the presence of oxygen and nitrate, and substrate-product stoichiometries indicated that acetate turnover was coupled to oxygen-dependent respiration and denitrification. The collective results suggest that acetate formed under anaerobic conditions might constitute a trophic link between anaerobic and aerobic processes in forest soils. PMID:16535147

  17. Dependence of laser-induced breakdown spectroscopy results on pulse energies and timing parameters using soil simulants.

    PubMed

    Kurek, Lauren; Najarian, Maya L; Cremers, David A; Chinni, Rosemarie C

    2013-01-01

    The dependence of some LIBS detection capabilities on lower pulse energies (<100 mJ) and timing parameters were examined using synthetic silicate samples. These samples were used as simulants for soil and contained minor and trace elements commonly found in soil at a wide range of concentrations. For this study, over 100 calibration curves were prepared using different pulse energies and timing parameters; detection limits and sensitivities were determined from the calibration curves. Plasma temperatures were also measured using Boltzmann plots for the various energies and the timing parameters tested. The electron density of the plasma was calculated using the full-width half maximum (FWHM) of the hydrogen line at 656.5 nm over the energies tested. Overall, the results indicate that the use of lower pulse energies and non-gated detection do not seriously compromise the analytical results. These results are very relevant to the design of field- and person-portable LIBS instruments.

  18. Dependence of Laser-induced Breakdown Spectroscopy Results on Pulse Energies and Timing Parameters Using Soil Simulants

    PubMed Central

    Kurek, Lauren; Najarian, Maya L.; Cremers, David A.; Chinni, Rosemarie C.

    2013-01-01

    The dependence of some LIBS detection capabilities on lower pulse energies (<100 mJ) and timing parameters were examined using synthetic silicate samples. These samples were used as simulants for soil and contained minor and trace elements commonly found in soil at a wide range of concentrations. For this study, over 100 calibration curves were prepared using different pulse energies and timing parameters; detection limits and sensitivities were determined from the calibration curves. Plasma temperatures were also measured using Boltzmann plots for the various energies and the timing parameters tested. The electron density of the plasma was calculated using the full-width half maximum (FWHM) of the hydrogen line at 656.5 nm over the energies tested. Overall, the results indicate that the use of lower pulse energies and non-gated detection do not seriously compromise the analytical results. These results are very relevant to the design of field- and person-portable LIBS instruments. PMID:24084606

  19. Main Parameters of Soil Quality and it's Management Under Changing Climate

    NASA Astrophysics Data System (ADS)

    László Phd, M., ,, Dr.

    2009-04-01

    Reviewing Paper Introduction: Malcolm summarised the topic of soil quality and it's management in a well synthetized form in 2000. So, the soils are fundamental to the well-being and productivity of agricultural and natural ecosystems. Soil quality is a concept being developed to characterize the usefulness and health of soils. Soil quality includes soil fertility, potential productivity, contaminant levels and their effects, resource sustainability and environmental quality. A general definition of soil quality is the degree of fitness of a soil for a specific use. The existence of multiple definitions suggests that the soil quality concept continues to evolve (Kádár, 1992; Várallyay, 1992, 1994, 2005; Németh, 1996; Malcolm, 2000; Márton, 2005; Márton et al. 2007). Recent attention has focused on the sustainability of human uses of soil, based on concerns that soil quality may be declining (Boehn and Anderson, 1997). We use sustainable to mean that a use or management of soil will sustain human well-being over time. Lal (1995) described the land resources of the world (of which soil is one component) as "finite, fragile, and nonrenewable," and reported that only about 22% (3.26 billion ha) of the total land area on the globe is suitable for cultivation and at present, only about 3% (450 million ha) has a high agricultural production capacity. Because soil is in large but finite supply, and some soil components cannot be renewed within a human time frame, the condition of soils in agriculture and the environment is an issue of global concern (Howard, 1993; FAO, 1997). Concerns include soil losses from erosion, maintaining agricultural productivity and system sustainability, protecting natural areas, and adverse effects of soil contamination on human health (Haberern, 1992; Howard, 1993; Sims et al., 1997). Parr et al. (1992) state, "...soil degradation is the single most destructive force diminishing the world's soil resource base." Soil quality guidelines

  20. Relation between soil temperature and biophysical parameters in Indian mustard seeds

    NASA Astrophysics Data System (ADS)

    Adak, T.; Chakravarty, N. V. K.

    2013-12-01

    Temporal changes in surface soil temperature were studied in winter crop. Significant changes in bare and cropped soil temperature were revealed. Air temperature showed a statistically positive and strong relationship (R2 = 0.79** to 0.92**) with the soil temperature both at morning and afternoon hours. Linear regression analysis indicated that each unit increase in ambient temperature would lead to increase in minimum and maximum soil temperatures by 1.04 and 1.02 degree, respectively. Statistically positive correlation was revealed among biophysical variables with the cumulative surface soil temperature. Linear and non-linear regression analysis indicated 62-69, 72-86 and 72-80% variation in Leaf area index, dry matter production and heat use efficiency in Indian mustard crop as a function of soil degree days. Below 60% variation in yield in Indian mustard was revealed as a function of soil temperature. In contrast, non-significant relationship between oil content and soil temperature was found, which suggests that oil accumulation in oilseed crops was not affected significantly by the soil temperature as an independent variable.

  1. Utilizing of magnetic parameters for evaluation of soil erosion rates on two different agricultural sites

    NASA Astrophysics Data System (ADS)

    Kapicka, A.; Grison, H.; Petrovsky, E.; Jaksik, O.; Kodesova, R.

    2015-12-01

    Field measurements of magnetic susceptibility were carried out on regular grid, resulting in 101 data points at Brumovice and 65 at Vidim locality. Mass specific magnetic susceptibility χ and its frequency dependence χFD was used to estimate the significance of SP ferrimagnetic particles of pedogenic origin in topsoil horizons. The lowest magnetic susceptibility was obtained on the steep valley sides. Here the original topsoil was eroded and mixed by tillage with the soil substrate (loess). Soil profiles unaffected by erosion were investigated in detail. The vertical distribution of magnetic susceptibility along these "virgin" profiles was measured in laboratory on samples collected with 2-cm spacing. The differences between the distribution of susceptibility in the undisturbed soil profiles and the magnetic signal after uniform mixing of the soil material as a result of erosion and tillage are fundamental for the estimation of soil loss in the studied test fields. Maximum cumulative soil erosion depth in Brumovice and Vidim is around 100 cm and 50 cm respectively. The magnetic method is suitable for mapping at the chernozem localities and measurement of soil magnetic susceptibility is in this case useful and fast technique for quantitative estimation of soil loss caused by erosion. However, it is less suitable (due to lower magnetic differentiation with depth) in areas with luvisol as dominant soil unit. Acknowledgement: This study was supported by NAZV Agency of the Ministry of Agriculture of the Czech Republic through grant No QJ1230319.

  2. Estimation of the ICBM/2 Organic Matter Simulation Model parameters for biogas digestate mineralisaion in soil using Near Infrared Data.

    NASA Astrophysics Data System (ADS)

    Cabassi, Giovanni; Cavalli, Daniele; Borrelli, Lamberto; Degano, Luigi; Marino Gallina, Pietro

    2014-05-01

    The use of simulation models to study the turnover of soil organic matter (SOM) can support experimental data interpretation and the optimization of manure management. Icbm/2 (Katter, 2001) is a SOM simulation model that describes the turnover of SOM with three pools : one for old humified SOM (CO) and two for added manure, CL ( labile "young" C) and CS (stable "young" C). C outflows from CL and CR to be humified (h) and lost as CO2-C (1-h). All pools decay with firs-order kinetics with parameter kYL, kYR and kO (fig. 1).With this model of SOM turnover, during manure decomposition into the soil, only the evolved CO2 can be easily measured. Near infrared spectroscopy has been proved to be a useful technique for soil C evaluation. Since different soil C pools are expected to have different chemical composition, it was proven that NIR can be used as a cheap technique to develop calibration models to estimate the amount of C belonging to different pools). The aim of this work was compare the calibration of ICBM/2 using C respiration data or optimal NIR prediction of CO and CL pools. A total of six laboratory treatments were established using the same soil corresponding to the application of five fertilisers and a control treatment: 1) control without N fertilisation; 2) ammonium sulphate; 3) anaerobically digested dairy cow slurry (Digested slurry); 4-5) the liquid (Liquid fraction) and solid (Solid fraction) fractions after mechanical separation of Digested slurry; and 6) anaerobically stored dairy cow slurry (Stored slurry). The "nursery" method was used with 12 sampling dates. NIR analysis were performed on the air dried grounded soils. Spectra were collected using an FT-NIR Spectrometer. Parameters calibration was done separately for each soil using the downhill simplex method. For each manure, a C partitioning factor (Fi) was optimised. In each optimization step respiration measured data or NIR estimates CL and CO were used as imput for minimisation objective

  3. Effects of dry bulk density and particle size fraction on gas transport parameters in variably saturated landfill cover soil

    SciTech Connect

    Wickramarachchi, Praneeth; Kawamoto, Ken; Hamamoto, Shoichiro; Nagamori, Masanao; Moldrup, Per; Komatsu, Toshiko

    2011-12-15

    Highlights: > The effects of soil physical properties on gas transport parameters were investigated. > Higher values of D{sub p} and k{sub a} exhibited in the '+gravel' than the '-gravel' fraction at same soil-air content ({epsilon}). > Recent power law models for D{sub p} (WLR) and k{sub a} (RPL) were modified. > Model parameters were linearly related to easily measurable dry bulk density ({rho}{sub b}). - Abstract: Landfill sites are emerging in climate change scenarios as a significant source of greenhouse gases. The compacted final soil cover at landfill sites plays a vital role for the emission, fate and transport of landfill gases. This study investigated the effects of dry bulk density, {rho}{sub b}, and particle size fraction on the main soil-gas transport parameters - soil-gas diffusivity (D{sub p}/D{sub o}, ratio of gas diffusion coefficients in soil and free air) and air permeability (k{sub a}) - under variably-saturated moisture conditions. Soil samples were prepared by three different compaction methods (Standard and Modified Proctor compaction, and hand compaction) with resulting {rho}{sub b} values ranging from 1.40 to 2.10 g cm{sup -3}. Results showed that D{sub p} and k{sub a} values for the '+gravel' fraction (<35 mm) became larger than for the '-gravel' fraction (<2 mm) under variably-saturated conditions for a given soil-air content ({epsilon}), likely due to enhanced gas diffusion and advection through less tortuous, large-pore networks. The effect of dry bulk density on D{sub p} and k{sub a} was most pronounced for the '+gravel' fraction. Normalized ratios were introduced for all soil-gas parameters: (i) for gas diffusivity D{sub p}/D{sub f}, the ratio of measured D{sub p} to D{sub p} in total porosity (f), (ii) for air permeability k{sub a}/k{sub a,pF4.1}, the ratio of measured k{sub a} to k{sub a} at 1235 kPa matric potential (=pF 4.1), and (iii) for soil-air content, the ratio of soil-air content ({epsilon}) to total porosity (f) (air

  4. Use of Magnetic Parameters to Asses Soil Erosion Rates on Agricultural Site

    NASA Astrophysics Data System (ADS)

    Petrovsky, E.; Kapicka, A.; Dlouha, S.; Jaksik, O.; Grison, H.; Kodesova, R.

    2014-12-01

    A detailed field study on a small test site of agricultural land situated in loess region in Southern Moravia (Czech Republic) and laboratory analyses were carried out in order to test the applicability of magnetic methods in assessing soil erosion. Haplic Chernozem, the original dominant soil unit in the area, is nowadays progressively transformed into different soil units along with intense soil erosion. As a result, an extremely diversified soil cover structure has developed due to the erosion. The site was characterized by a flat upper part while the middle part, formed by a substantive side valley, is steeper. We carried out field measurements of magnetic susceptibility on a regular grid, resulting in 101 data points. The bulk soil material for laboratory investigation was gathered from all the grid points. Values of the magnetic susceptibility are spatially distributed depending on the terrain. Higher values were measured in the flat upper part (where the original top horizon remained). The lowest values of were obtained on the steep valley sides. Here the original topsoil was eroded and mixed by tillage with the soil substrate (loess). A soil profile unaffected by erosion was investigated in detail. The vertical distribution of magnetic susceptibility along this "virgin" profile was measured in laboratory on the samples collected with 2-cm spacing. The undisturbed profile shows several soil horizons. Horizons Ac and A show a slight increase in magnetic susceptibility up to a depth of about 70 cm. Horizon A/Ck is characterized by a decrease in susceptibility, and the underlying C horizon (h > 103 cm) has a very low value of magnetic susceptibility. The differences between the values of susceptibility in the undisturbed soil profile and the magnetic signal after uniform mixing the soil material as a result of tillage and erosion are fundamental for the estimation of soil loss in the studied test field. Using the uneroded profile from the studied locality as a

  5. The benefits of using remotely sensed soil moisture in parameter identification of large-scale hydrological models

    NASA Astrophysics Data System (ADS)

    Wanders, Niko; Bierkens, Marc F. P.; de Jong, Steven M.; de Roo, Ad; Karssenberg, Derek

    2013-04-01

    Nowadays large-scale hydrological models are mostly calibrated using observed discharge. Although this may lead to accurate hydrograph estimation, calibration on discharge is restricted to parameters that directly affect discharge. As a result, a large part of the hydrological system that is not directly linked to discharge, in particular the unsaturated zone, remains uncalibrated, or might be modified unrealistically. Soil moisture observations from satellites have the potential to fill this gap, as these provide a direct measurement of the state of the unsaturated zone, and thus are potentially useful in calibrating unsaturated zone model parameters. This is expected to result in a better identification of the complete hydrological system, potentially leading to improved forecasts of the hydrograph as well. Here we evaluate this added value of remotely sensed soil moisture in calibration of large-scale hydrological models by addressing two research questions: 1) Does calibration on remotely sensed soil moisture lead to an improved identification of hydrological models compared to approaches that calibrate on discharge alone? 2) If this is the case, what is the improvement in the forecasted hydrograph? To answer these questions we use a dual state and parameter ensemble Kalman filter to calibrate the hydrological model LISFLOOD for the Upper-Danube area. Calibration is done with discharge and remotely sensed soil moisture from AMSR-E, SMOS and ASCAT. Estimates and spatial correlation are derived from a previous published study on the quantification of the errors and spatial error structure of microwave remote sensing techniques. Four scenarios are studied, namely, no calibration (expert knowledge), calibration on discharge, calibration on remote sensing data and calibration on both discharge and remote sensing data. Using a split-sample approach, the model is calibrated for a period of 2 years and validated using a validation period of 10 years with the calibrated

  6. On the Value of Effective Parameters Obtained Under Reduced Spatial Scale Mismatch to Represent Soil Moisture - Evapotranspiration Interactions in Land Surface Models.

    NASA Astrophysics Data System (ADS)

    Rosolem, R.; Iwema, J.; Blyth, E.; Wagener, T.; Rahman, A. S. M. M.

    2015-12-01

    Soil moisture - evapotranspiration interactions have been studied in several regions characterized by distinct soil properties, land cover types, and climate. Such interactions are usually assessed with measurements representing different spatial footprint. For example, soil moisture measurements obtained from point-scale sensors or with remote sensing products are typically compared with evapotranspiration measurements obtained with eddy covariance systems. With efforts to develop hydrometeorological models capable of simulating processes at hyper-resolution (i.e., 1 sq-km), novel approaches for intermediate-scale soil moisture measurements give us new opportunities to evaluate the representation of soil moisture and evapotranspiration processes at similar spatial scales. Here, we evaluate the performance of the Joint UK Land Environment Simulator (JULES) in which key parameters are determined effectively based on both soil moisture and evapotranspiration measurements obtained with similar horizontal footprint. We use soil moisture data from selected sites in the COsmic-ray Soil Moisture Observing System (COSMOS) network in combination with co-located Ameriflux eddy covariance towers to constrain key parameters in JULES assuming their similar horizontal footprint of hundreds of meters. The COSMOS-Ameriflux sites are characterized by distinct soils, land cover types, and climate. In addition, point-scale soil moisture at each site is also used in combination with eddy covariance measurements to constrain JULES parameters, while recognizing its much smaller support volume. Each individual site is ranked based on differences in soil moisture dynamics from both point-scale and intermediate-scale measurements. Model calibration is carried out by optimizing JULES performance against (1) point-scale soil moisture only, (2) cosmic-ray soil moisture only, (3) point-scale soil moisture and surface fluxes, and (4) cosmic-ray soil moisture and surface fluxes. We then evaluate

  7. H-binding groups in lignite vs. soil humic acids: NICA-Donnan and spectroscopic parameters

    SciTech Connect

    Drosos, M.; Jerzykiewicz, M.; Deligiannakis, Y.

    2009-04-15

    A comparative study has been carried out for two sets of humic acids isolated from lignites and soils. H-binding data were analyzed using the NICA-Donnan model, for three Greek lignite humic acids (HA) plus IHSS Leonardite reference HA, and five Greek soil HAs plus a commercial peat HA. {sup 13}C-CP-MAS NMR and H-binding data provide quantitative estimates for functional groups, showing that lignite HAs of diverse origin have strikingly homogeneous properties, while the H-binding structural units of soil HAs are characterized by a large degree of variability. Consistent differences between soil HA vs. lignite HA are revealed at the level of functional groups' concentrations. In the pH range 4 to 10, soil HA showed a charge variation < 3 (equiv kg{sup -1}) while lignite HAs showed a higher charge variation > 3.5 (equiv kg{sup -1}).

  8. Relationships between petrophysical, sedimentological and microstructural properties of the Oolithes Blanche formation, a saline aquifer in the Paris Basin.

    NASA Astrophysics Data System (ADS)

    Casteleyn, Lisa; Robion, Philippe; Collin, Pierry-Yves; Menéndez, Beatriz; David, Christian; Fernandes, Nathalie; Desaubliaux, Guy; Dreux, Rémi; Rigollet, Christophe; Badinier, Guillaume

    2010-05-01

    The Paris Basin appears to be appropriate in terms of CO2 capture and storage when considering both the amount of CO2 produced and the availability of depleted fields and deep saline aquifers. The purpose of this study is to investigate the petrophysical properties in relation with the sedimento-diagenetic environment of the "Oolithe Blanche" formation (Dogger), a deep saline aquifer considered as a potential candidate for CO2 storage. Regarding the scarcity of the core data in the Paris Basin, our investigation was firstly based on the study of field analogs in the south-east of the Paris Basin. The Oolithe Blanche Formation is composed of very shallow marine oolitic and bioclastic limestones, mainly grainstones. Three main sedimentological fabrics were defined: tide-dominated, wave-dominated (oolitic shoal) and prograding oolitic shoal fabrics. These three fabrics show subtle variations in composition (ooliths vs bioclasts) and in the distribution of the carbonate textures. The Oolithe Blanche Formation (Bathonian) is 70-80 meters thick and water salinity ranges from 1 to 4 g NaCl/l. 18 oriented blocks were collected on outcrops selected for the different sedimentological facies recognised in the formation: 9 blocks in the Bierry Lès Belles Fontaines quarry (Yonne), 5 blocks in the Ravières quarries (Côte d'Or) and 4 blocks in the Massangis quarry (Yonne). On each block, several petrophysical properties were measured on three perpendicular plugs: porosity, pore size distribution derived from mercury injection tests, permeability, capillary imbibition parameters, electrical conductivity and acoustic velocities. The sedimento-diagenetic fabric and microstructural analysis was defined by using optical microscope and scanning electron microscopy, coupled with image analysis on thin sections. The porosity measured using the water saturation triple weight method ranges from 6% to 34%. The permeability values are low, between 0.1 mD and 9 mD. The data from the

  9. Experimental parameters optimization of instrumental neutron activation analysis in order to determine selected elements in some industrial soils in Turkey

    NASA Astrophysics Data System (ADS)

    Haciyakupoglu, Sevilay; Nur Esen, Ayse; Erenturk, Sema

    2014-08-01

    The purpose of this study is optimization of the experimental parameters for analysis of soil matrix by instrumental neutron activation analysis and quantitative determination of barium, cerium, lanthanum, rubidium, scandium and thorium in soil samples collected from industrialized urban areas near Istanbul. Samples were irradiated in TRIGA MARK II Research Reactor of Istanbul Technical University. Two types of reference materials were used to check the accuracy of the applied method. The achieved results were found to be in compliance with certified values of the reference materials. The calculated En numbers for mentioned elements were found to be less than 1. The presented data of element concentrations in soil samples will help to trace the pollution as an impact of urbanization and industrialization, as well as providing database for future studies.

  10. RELATIONSHIPS BETWEEN SOME SOIL PARAMETERS AND WEED COMMUNITY (CASE STUDY: WINTER WHEAT FIELDS OF UREMIA-IRAN).

    PubMed

    Hassannejad, S; Pirouie, M Saleh; Haghi, D Zare

    2015-01-01

    In order to find relationships between weed species distribution and soil pH, calcium carbonate (CaCO₃), electrical conductivity (EC), and organic matter percentage (OM %), fields surveys were done in 50 wheats (Triticum aestivum L.) fields of Uremia county (one of the northwest counties of Iran) in 2013. Data sampling of weeds was conducted from the beginning of stem elongation until the end of heading stages of wheat. In each field, 20 quadrates (0.25 m²) were randomly placed along a "W" pattern (5 quadrates in each line of this pattern) and in each quadrat, weed species were coded and recorded (density and cover percentage) for subsequent data entry and analysis. Canonical correspondence analysis (CCA) was used to find relationships between presence and absence of weeds in wheat fields and some of soil parameters. A total 169 weed species belonging to 35 plant families were recorded. CCA showed that four soil factors including soil pH, calcium carbonate (CaCO3), electrical conductivity (EC), and organic matter percentage (OM %) showed 58.6 percentage of weed species distribution variance. Abutilon theophrasti Medicus, Datura stramonium L., Malva neglecta Wallr., Portulaca oleracea L., Sisymbrium irio L., Atriplex patulum (L.). Aellen., and Heliotropium europaeum L. had maximum correlation with soil's pH. Euphorbia peplus L. and Salvia spinosa L. had negative correlation with pH, so that increasing pH caused reduction in the presence of these weeds. The presence of Chondrilla juncea L., Lepidium perfoliatum L., and Turgenia latifolia (L.) Hoff in the center of CCA biplot indicated that these weeds were correlated with all of these soil parameters.

  11. RELATIONSHIPS BETWEEN SOME SOIL PARAMETERS AND WEED COMMUNITY (CASE STUDY: WINTER WHEAT FIELDS OF UREMIA-IRAN).

    PubMed

    Hassannejad, S; Pirouie, M Saleh; Haghi, D Zare

    2015-01-01

    In order to find relationships between weed species distribution and soil pH, calcium carbonate (CaCO₃), electrical conductivity (EC), and organic matter percentage (OM %), fields surveys were done in 50 wheats (Triticum aestivum L.) fields of Uremia county (one of the northwest counties of Iran) in 2013. Data sampling of weeds was conducted from the beginning of stem elongation until the end of heading stages of wheat. In each field, 20 quadrates (0.25 m²) were randomly placed along a "W" pattern (5 quadrates in each line of this pattern) and in each quadrat, weed species were coded and recorded (density and cover percentage) for subsequent data entry and analysis. Canonical correspondence analysis (CCA) was used to find relationships between presence and absence of weeds in wheat fields and some of soil parameters. A total 169 weed species belonging to 35 plant families were recorded. CCA showed that four soil factors including soil pH, calcium carbonate (CaCO3), electrical conductivity (EC), and organic matter percentage (OM %) showed 58.6 percentage of weed species distribution variance. Abutilon theophrasti Medicus, Datura stramonium L., Malva neglecta Wallr., Portulaca oleracea L., Sisymbrium irio L., Atriplex patulum (L.). Aellen., and Heliotropium europaeum L. had maximum correlation with soil's pH. Euphorbia peplus L. and Salvia spinosa L. had negative correlation with pH, so that increasing pH caused reduction in the presence of these weeds. The presence of Chondrilla juncea L., Lepidium perfoliatum L., and Turgenia latifolia (L.) Hoff in the center of CCA biplot indicated that these weeds were correlated with all of these soil parameters. PMID:27145592

  12. Changes of petrophysical properties of sandstones due to interaction with carbon dioxide, a laboratory study

    NASA Astrophysics Data System (ADS)

    Nover, Georg; von der Gönna, Jutta; Heikamp, Stephanie; Köster, Jens

    2013-04-01

    Changes of petrophysical, petrological, mineralogical, mechanical and chemical parameters were studied on sandstones from the Hessian depression and sandstones from Neidenbach (Eifel) before and after alteration with CO2. The experiments were performed in a wide pressure and temperature range (p >10<20 MPa; T > 100<200°C) to cover the pressure and temperature conditions of most promising deep saline aquifers, with the consequence that CO2 is above the critical point and thus in supercritical state (scCO2). The experiments lasted from 10 days up to more than 6 month. In repeated experiments samples were analyzed after every 2 up to 6 weeks reaction time. Experiments were performed in two different setups, i) the pore volume was fully saturated with a CO2-saturated artificial brine (3 M NaCl-solution) and ii) the pore volume was partially saturated with brine and in direct contact with wet CO2. Initial values of the untreated samples exhibit quartz to range from < 50% up to >85 weight %, density from 2.62 - 2.70 g/cm3, porosity from < 10% up to > 25% and permeability from < 10-17 up to 10-12 m². In both experimental setups porosity increased by less than 2 vol%. The increase in permeability was less than one order in magnitude for i) and more than 1.5 orders in magnitude for ii). The mineralogical composition was unchanged within the detection limit of powder X-Ray diffraction (XRD), while X-Ray Fluorescence Analysis (XRF) indicated mobilization of calcium, magnesium, aluminum and potassium. Dissolution was confirmed by the chemical analysis (ICP-OES-MS) of recovered artificial brines that showed an increase of the ionic species Ca, Mg, Al and K after the scCO2-experiments. Partial solution of feldspar and clay was detected by optical inspection and scanning electron microprobe SEM-analysis. Low frequency electrical conductivity experiments (SIP, spectral induced polarization) exhibited both, a significant increase in conductivity that could be explained by

  13. The ratio of clay content to total organic carbon content is a useful parameter to predict adsorption of the herbicide butachlor in soils.

    PubMed

    Liu, Zhongzhen; He, Yan; Xu, Jianming; Huang, Panming; Jilani, Ghulam

    2008-03-01

    Thirteen soils collected from 11 provinces in eastern China were used to investigate the butachlor adsorption. The results indicated that the total organic carbon (TOC) content, clay content, amorphous Fe2O3 content, silt content, CEC, and pH had a combined effect on the butachlor sorption on soil. Combination of the data obtained from the 13 soils in the present study with other 23 soil samples reported by other researchers in the literature showed that Koc would be a poor predictive parameter for butachlor adsorption on soils with TOC content higher than 4.0% and lower than 0.2%. The soils with the ratio of clay content to TOC content (RCO) values less than 60 adsorbed butachlor mainly by the partition into soil organic matter matrix. The soils with RCO values higher than 60 apparently adsorbed butachlor by the combination of the partition into soil organic matter matrix and adsorption on clay surface.

  14. Soil and geomorphological parameters to characterize natural environmental and human induced changes within the Guadarrama Range (Central Spain)

    NASA Astrophysics Data System (ADS)

    Schmid, Thomas; Inclán-Cuartas, Rosa M.; Santolaria-Canales, Edmundo; Saa, Antonio; Rodríguez-Rastrero, Manuel; Tanarro-Garcia, Luis M.; Luque, Esperanza; Pelayo, Marta; Ubeda, Jose; Tarquis, Ana; Diaz-Puente, Javier; De Marcos, Javier; Rodriguez-Alonso, Javier; Hernandez, Carlos; Palacios, David; Gallardo-Díaz, Juan; Fidel González-Rouco, J.

    2016-04-01

    Mediterranean mountain ecosystems are often complex and remarkably diverse and are seen as important sources of biological diversity. They play a key role in the water and sediment cycle for lowland regions as well as preventing and mitigating natural hazards especially those related to drought such as fire risk. However, these ecosystems are fragile and vulnerable to changes due to their particular and extreme climatic and biogeographic conditions. Some of the main pressures on mountain biodiversity are caused by changes in land use practices, infrastructure and urban development, unsustainable tourism, overexploitation of natural resources, fragmentation of habitats, particularly when located close to large population centers, as well as by pressures related toclimate change. The objective of this work is to select soil and geomorphological parameters in order to characterize natural environmental and human induced changes within the newly created National Park of the Sierra de Guadarrama in Central Spain, where the presence of the Madrid metropolitan area is the main factor of impact. This is carried out within the framework of the Guadarrama Monitoring Network (GuMNet) of the Campus de ExcelenciaInternacionalMoncloa, where long-term monitoring of the atmosphere, soil and bedrock are priority. This network has a total of ten stations located to the NW of Madrid and in this case, three stations have been selected to represent different ecosystems that include: 1) an alluvial plain in a lowland pasture area (La Herreria at 920 m a.s.l.), 2) mid mountain pine-forested and pasture area (Raso del Pino at 1801 m a.s.l.) and 3) high mountain grassland and rock area (Dos Hermanas at 2225 m a.s.l.). At each station a site geomorphological description, soil profile description and sampling was carried out. In the high mountain area information was obtained for monitoring frost heave activity and downslope soil movement. Basic soil laboratory analyses have been carried out

  15. Soil Parameters for Representing a Karst Geologic Terrain in the Noah Land-Surface Model over Tennessee and Kentucky

    NASA Astrophysics Data System (ADS)

    Sullivan, Z.; Fan, X.

    2015-12-01

    Currently, the Noah Land-Surface Model (Noah-LSM) coupled with the Weather Research and Forecasting (WRF) model does not have a representation of the physical behavior of a karst terrain found in a large area of Tennessee and Kentucky and 25% of land area worldwide. The soluble nature of the bedrock within a karst geologic terrains allows for the formation of caverns, joints, fissures, sinkholes, and underground streams which affect the hydrological behavior of the region. The Highland Rim of Tennessee and the Pennyroyal Plateau and Bluegrass region of Kentucky make up a larger karst area known as the Interior Low Plateau. The highly weathered upper portion of the karst terrain, known as the epikarst, allows for more rapid transport of water through the system. For this study, hydrological aspects, such as bedrock porosity and the hydraulic conductivity, were chosen within this region in order to determine the most representative subsurface parameters for the Noah-LSM. These values along with the use of similar proxy values were chosen to calculate and represent the remaining eight parameters within the SOILPARM.TBL for the WRF model. Hydraulic conductivity values show a variation ranging from around 10-7 and 10-5 ms-1 for the karst bedrock within this region. A sand and clay soil type was used along with bedrock parameters to determine an average soil parameter type for the epikarst bedrock located within this region. Results from this study show parameters for an epikarst bedrock type displaying higher water transport through the system, similar to that of a sandy soil type with a water retention similar to that of a loam type soil. The physical nature of epikarst may lead to a decrease in latent heat values over this region and increase sensible heat values. This, in turn, may effect boundary layer growth which could lead to convective development. Future modeling work can be conducted using these values by way of coupling the soil parameters with the karst

  16. EFFECTS OF THE VARIATION OF SELECT SAMPLING PARAMETERS ON SOIL VAPOR CONCENTRATIONS

    EPA Science Inventory

    Currently soil vapor surveys are commonly used as a screening technique to delineate subsurface volatile organic compound (VOC) contaminant plumes and to provide information for vapor intrusion and contaminated site evaluations. To improve our understanding of the fate and transp...

  17. Constraining soil hydraulic parameter and output uncertainty of the distributed hydrological MIKE SHE model using the GLUE framework

    NASA Astrophysics Data System (ADS)

    Christiaens, K.; Feyen, J.

    2002-02-01

    Both calibration and uncertainty assessment are mandatory steps in today's modelling process. The former considers both the inputs (input variables and parameters) as well as model results. An exploratory investigation of the applicable parameter space results in a wide spectrum of values for a specific model output. By retaining only those model realizations that mimic reality in a sufficient way, inputs and associated response can be constrained, thereby quantifying the uncertainty involved. The generalized likelihood uncertainty estimation (GLUE) framework provides a structured methodology for this purpose.The study presented focuses on the applicability of the GLUE framework within the context of the distributed hydrological model MIKE SHE. Even though all significant processes involved are incorporated within the model, the problems of calibration and uncertainty assessment cannot be avoided. This has resulted in a quest for well-delineated effective parameters crucial for sound mechanistic model application. Being a complex model, the number of possible realizations using MIKE SHE is fairly small due to computing time, and an in-depth exploratory approach is impossible. On the other hand, several output variables are available aside from the hydrological river response, like water content in the soil profile or ground water level, which can be used for retaining realistic parameter sets.This study presents some preliminary results on the applicability of the GLUE-MIKE SHE framework and associated constrained preliminary parameter and output uncertainty values. Focus was given to the influence of soil hydraulic parameters on the hydrological behaviour of a small study basin. The soil hydraulic parameters were predicted using various pedo-transfer-function approaches and moisture retention measurements in the laboratory, and these distributions were then confronted with ranges of the constrained effective parameters. For the latter, the restrictions that were

  18. Use of airborne hyperspectral imagery to map soil parameters in tilled agricultural fields

    USGS Publications Warehouse

    Hively, W. Dean; McCarty, Gregory W.; Reeves, James B.; Lang, Megan W.; Oesterling, Robert A.; Delwiche, Stephen R.

    2011-01-01

    Soil hyperspectral reflectance imagery was obtained for six tilled (soil) agricultural fields using an airborne imaging spectrometer (400–2450 nm, ~10 nm resolution, 2.5 m spatial resolution). Surface soil samples (n = 315) were analyzed for carbon content, particle size distribution, and 15 agronomically important elements (Mehlich-III extraction). When partial least squares (PLS) regression of imagery-derived reflectance spectra was used to predict analyte concentrations, 13 of the 19 analytes were predicted with R2 > 0.50, including carbon (0.65), aluminum (0.76), iron (0.75), and silt content (0.79). Comparison of 15 spectral math preprocessing treatments showed that a simple first derivative worked well for nearly all analytes. The resulting PLS factors were exported as a vector of coefficients and used to calculate predicted maps of soil properties for each field. Image smoothing with a 3 × 3 low-pass filter prior to spectral data extraction improved prediction accuracy. The resulting raster maps showed variation associated with topographic factors, indicating the effect of soil redistribution and moisture regime on in-field spatial variability. High-resolution maps of soil analyte concentrations can be used to improve precision environmental management of farmlands.

  19. Network analysis reveals that bacteria and fungi form modules that correlate independently with soil parameters.

    PubMed

    de Menezes, Alexandre B; Prendergast-Miller, Miranda T; Richardson, Alan E; Toscas, Peter; Farrell, Mark; Macdonald, Lynne M; Baker, Geoff; Wark, Tim; Thrall, Peter H

    2015-08-01

    Network and multivariate statistical analyses were performed to determine interactions between bacterial and fungal community terminal restriction length polymorphisms as well as soil properties in paired woodland and pasture sites. Canonical correspondence analysis (CCA) revealed that shifts in woodland community composition correlated with soil dissolved organic carbon, while changes in pasture community composition correlated with moisture, nitrogen and phosphorus. Weighted correlation network analysis detected two distinct microbial modules per land use. Bacterial and fungal ribotypes did not group separately, rather all modules comprised of both bacterial and fungal ribotypes. Woodland modules had a similar fungal : bacterial ribotype ratio, while in the pasture, one module was fungal dominated. There was no correspondence between pasture and woodland modules in their ribotype composition. The modules had different relationships to soil variables, and these contrasts were not detected without the use of network analysis. This study demonstrated that fungi and bacteria, components of the soil microbial communities usually treated as separate functional groups as in a CCA approach, were co-correlated and formed distinct associations in these adjacent habitats. Understanding these distinct modular associations may shed more light on their niche space in the soil environment, and allow a more realistic description of soil microbial ecology and function.

  20. Influence of spatial variability of hydraulic characteristics of soils on surface parameters obtained from remote sensing data in infrared and microwaves

    NASA Technical Reports Server (NTRS)

    Brunet, Y.; Vauclin, M.

    1985-01-01

    The correct interpretation of thermal and hydraulic soil parameters infrared from remotely sensed data (thermal infrared, microwaves) implies a good understanding of the causes of their temporal and spatial variability. Given this necessity, the sensitivity of the surface variables (temperature, moisture) to the spatial variability of hydraulic soil properties is tested with a numerical model of heat and mass transfer between bare soil and atmosphere. The spatial variability of hydraulic soil properties is taken into account in terms of the scaling factor. For a given soil, the knowledge of its frequency distribution allows a stochastic use of the model. The results are treated statistically, and the part of the variability of soil surface parameters due to that of soil hydraulic properties is evaluated quantitatively.

  1. Simulation of future groundwater recharge using a climate model ensemble and SAR-image based soil parameter distributions - A case study in an intensively-used Mediterranean catchment.

    PubMed

    Herrmann, Frank; Baghdadi, Nicolas; Blaschek, Michael; Deidda, Roberto; Duttmann, Rainer; La Jeunesse, Isabelle; Sellami, Haykel; Vereecken, Harry; Wendland, Frank

    2016-02-01

    We used observed climate data, an ensemble of four GCM-RCM combinations (global and regional climate models) and the water balance model mGROWA to estimate present and future groundwater recharge for the intensively-used Thau lagoon catchment in southern France. In addition to a highly resolved soil map, soil moisture distributions obtained from SAR-images (Synthetic Aperture Radar) were used to derive the spatial distribution of soil parameters covering the full simulation domain. Doing so helped us to assess the impact of different soil parameter sources on the modelled groundwater recharge levels. Groundwater recharge was simulated in monthly time steps using the ensemble approach and analysed in its spatial and temporal variability. The soil parameters originating from both sources led to very similar groundwater recharge rates, proving that soil parameters derived from SAR images may replace traditionally used soil maps in regions where soil maps are sparse or missing. Additionally, we showed that the variance in different GCM-RCMs influences the projected magnitude of future groundwater recharge change significantly more than the variance in the soil parameter distributions derived from the two different sources. For the period between 1950 and 2100, climate change impacts based on the climate model ensemble indicated that overall groundwater recharge will possibly show a low to moderate decrease in the Thau catchment. However, as no clear trend resulted from the ensemble simulations, reliable recommendations for adapting the regional groundwater management to changed available groundwater volumes could not be derived.

  2. Simulation of future groundwater recharge using a climate model ensemble and SAR-image based soil parameter distributions - A case study in an intensively-used Mediterranean catchment.

    PubMed

    Herrmann, Frank; Baghdadi, Nicolas; Blaschek, Michael; Deidda, Roberto; Duttmann, Rainer; La Jeunesse, Isabelle; Sellami, Haykel; Vereecken, Harry; Wendland, Frank

    2016-02-01

    We used observed climate data, an ensemble of four GCM-RCM combinations (global and regional climate models) and the water balance model mGROWA to estimate present and future groundwater recharge for the intensively-used Thau lagoon catchment in southern France. In addition to a highly resolved soil map, soil moisture distributions obtained from SAR-images (Synthetic Aperture Radar) were used to derive the spatial distribution of soil parameters covering the full simulation domain. Doing so helped us to assess the impact of different soil parameter sources on the modelled groundwater recharge levels. Groundwater recharge was simulated in monthly time steps using the ensemble approach and analysed in its spatial and temporal variability. The soil parameters originating from both sources led to very similar groundwater recharge rates, proving that soil parameters derived from SAR images may replace traditionally used soil maps in regions where soil maps are sparse or missing. Additionally, we showed that the variance in different GCM-RCMs influences the projected magnitude of future groundwater recharge change significantly more than the variance in the soil parameter distributions derived from the two different sources. For the period between 1950 and 2100, climate change impacts based on the climate model ensemble indicated that overall groundwater recharge will possibly show a low to moderate decrease in the Thau catchment. However, as no clear trend resulted from the ensemble simulations, reliable recommendations for adapting the regional groundwater management to changed available groundwater volumes could not be derived. PMID:26190446

  3. Evaluation of soil, unsaturated, and saturated zone parameter uncertainty using GSFlow and PEST in an agricultural watershed

    NASA Astrophysics Data System (ADS)

    Zuidema, S.; Davis, J. M.

    2011-12-01

    A coupled surface-ground water hydrological model of the Burley-DeMerritt Organic Dairy Research Farm in southeastern New Hampshire is under continued development in support of a long-term mission to understand nutrient dynamics and water use in sustainable New England dairy operations. To build on previous simulations of ground water recharge and nitrogen transport, an estimate of net recharge under an array of climate scenarios is required to facilitate modeling of nutrient dynamics for the projected life span of the dairy farm. The model must therefore incorporate spatially distributed surface and soil zone processes that influence the shallow ground water system. GSFlow couples the USGS Precipitation Runoff Modeling System and MODFLOW codes and is used to simulate surface, soil, and subsurface hydrological processes using a suite of empirical and process-based algorithms and parameters. Topography of the 83 hectare model domain was derived from a 1-meter horizontal resolution LiDAR DEM with centimeter-scale accuracy. Zonation at the soil surface was derived from detailed soils mapping, aerial land cover assessment, and drainage boundaries derived from the LiDAR DEM. Meteorological forcing data are taken from nearby (5 km) NCDC and AIRMAP meteorological towers. The farm's catchment consists of regionally common land covers including pasture, forest, and forested wetland. An array of surface model structures and spatial discretizations are evaluated ranging from fine scale, incorporating areas of consistent land cover or soil types, to the catchment scale. Parameter identification and uncertainty for both PRMS and MODFLOW components is conducted using PEST software, where distributed measurements of hydraulic head, soil moisture, and streamflow are weighted by measurement uncertainty and the relative measurement abundance or redundancy to define a model to measurement misfit objective function. Model validation will be conducted against data collected in the

  4. [Effect of soil water potential on hydraulic parameters of Fraxinus mandshurica seedlings].

    PubMed

    Cui, Xiaoyang; Song, Jinfeng; Qu, Minghua

    2004-12-01

    In this paper, soil water potential was controlled in the ranges of 0-(-)20 kPa (W1), -20-(-)40 kPa (W2), -40-(-)60 kPa (W3), -60-(-)80 kPa (W4) and -80-(-)160 kPa (W5) by a suite of specially designed root-sphere osmotic irrigation technique, and the dynamics of transpiration, water suction, tissue water potential and hydraulic resistance of Fraxinus mandshurica seedlings grown under these soil water conditions were studied. The results indicated that under sub-saturated soil water condition (W1), fine root water potential fluctuated at high levels from -0.08 MPa to -0.19 MPa, which brought about the lowest soil-root hydraulic resistance (35.52 MPa x s(-1) x m(-2) x mol(-1) in diurnal average), the highest water suction rate (4.44 mmol x m(-2) x s(-1) in average from 10:00 to 14:00), and the strongest transpiration rate (5.11 mmol x m(-2) x s(-1) in average from 10:00 to 14:00). Under field capacity (W2), soil-root hydraulic resistance increased several times above that under W1, water suction rate and transpiration rate declined significantly, while the diurnal single-peak pattern of transpiration was not altered. Under orderly increased soil water stress (W3-W5), soil-root hydraulic resistance (the average from 10:00 to 14:00) increased approximately 10-24 times above that under W1, which caused the consequent low water suction rate and low fluctuation levels of leaf water potential (-1.25 MPa-(-)1.94 MPa for W5), and transpiration was seriously restricted (the transpiration rate being only 0.91-1.55 mmol x m(-2) x s(-1) at midday for W3-W5). It is concluded that soil water was not equally available to Fraxinus mandshurica seedlings in the test ranges of soil water potential, and significant water stress could occur when the soil water potential was lower than -40 kPa.

  5. Assessment of structural model and parameter uncertainty with a multi-model system for soil water balance models

    NASA Astrophysics Data System (ADS)

    Michalik, Thomas; Multsch, Sebastian; Frede, Hans-Georg; Breuer, Lutz

    2016-04-01

    Water for agriculture is strongly limited in arid and semi-arid regions and often of low quality in terms of salinity. The application of saline waters for irrigation increases the salt load in the rooting zone and has to be managed by leaching to maintain a healthy soil, i.e. to wash out salts by additional irrigation. Dynamic simulation models are helpful tools to calculate the root zone water fluxes and soil salinity content in order to investigate best management practices. However, there is little information on structural and parameter uncertainty for simulations regarding the water and salt balance of saline irrigation. Hence, we established a multi-model system with four different models (AquaCrop, RZWQM, SWAP, Hydrus1D/UNSATCHEM) to analyze the structural and parameter uncertainty by using the Global Likelihood and Uncertainty Estimation (GLUE) method. Hydrus1D/UNSATCHEM and SWAP were set up with multiple sets of different implemented functions (e.g. matric and osmotic stress for root water uptake) which results in a broad range of different model structures. The simulations were evaluated against soil water and salinity content observations. The posterior distribution of the GLUE analysis gives behavioral parameters sets and reveals uncertainty intervals for parameter uncertainty. Throughout all of the model sets, most parameters accounting for the soil water balance show a low uncertainty, only one or two out of five to six parameters in each model set displays a high uncertainty (e.g. pore-size distribution index in SWAP and Hydrus1D/UNSATCHEM). The differences between the models and model setups reveal the structural uncertainty. The highest structural uncertainty is observed for deep percolation fluxes between the model sets of Hydrus1D/UNSATCHEM (~200 mm) and RZWQM (~500 mm) that are more than twice as high for the latter. The model sets show a high variation in uncertainty intervals for deep percolation as well, with an interquartile range (IQR) of

  6. Identifying unsaturated soil hydraulic parameters using integrated hydrogeophysical inversion approach on time-lapse ground-penetrating radar data

    NASA Astrophysics Data System (ADS)

    Jadoon, K. Z.; Weihermüller, L.; Scharnagl, B.; Kowalsky, M. B.; Bechtold, M.; Hubbard, S. S.; Vereecken, H.; Lambot, S.

    2012-04-01

    Recently, ground-penetrating radar (GPR) has proven to have a great potential for high resolution, non-invasive mapping of the soil hydrogeophysical properties at the scale of interest. Common GPR techniques are usually based on ray-based travel time or reflection analyses to retrieve soil dielectric permittivity, which is strongly correlated to soil water content. These methods suffer, however, from two major limitations. First, only a part of the information in the GPR signal is considered (e.g., propagation time). Second, the forward model describing the radar data is subject to relatively strong simplifications with respect to electromagnetic wave propagation phenomena. These limitations typically results in errors in the reconstructed water content images and, moreover, this does not permit to exploit all information contained in the radar data. We explored an alternative method by using full-waveform hydrogeophysical inversion of time-lapse, proximal GPR data to remotely estimate the unsaturated soil hydraulic properties. The radar system is based on international standard vector network analyzer technology and a full-waveform model is used to describe wave propagation in the antenna-air-soil system, including antenna-soil interactions. A hydrodynamic model is used to constrain the inverse electromagnetic problem in reconstructing continuous vertical water content profiles. In that case the estimated parameters reduce to the soil hydraulic properties, thereby strongly reducing the dimensionality of the inverse problem. In this study, we present an application of the proposed method to a data set collected in a field experiment. The GPR model involves a full-waveform frequency-domain solution of Maxwell's equations for wave propagation in three-dimensional multilayered media. The hydrodynamic model used in this work is based on a one-dimensional solution of Richards equation and the hydrological simulator HYDRUS 1-D was used with a single- and dual

  7. Methane emission characteristics and its relations with plant and soil parameters under irrigated rice ecosystem of northeast India.

    PubMed

    Gogoi, Nirmali; Baruah, K K; Gogoi, Boby; Gupta, Prabhat K

    2005-06-01

    Methane flux from rice varieties grown under two identical soils of Assam were monitored. In the first experiment, variety Jaya and GRT was grown in sandy loam soil of Lower Brahmaputra Valley Zone of Assam and the second experiment was conducted with variety Jyotiprasad and Bishnuprasad in sandy to sandy loam soils of Upper Brahmaputra Valley Zones of Assam. Methane flux recorded from variety Jyotiprasad and GRT was higher compared to variety Bishnuprasad and Jaya. The seasonal integrated flux recorded was 10.76 gm(-2), 9.98 gm(-2), 9.74 gm(-2) and 11.31 gm(-2) for variety GRT, Jaya, Bishnuprasad and Jyotiprasad, respectively. All the varieties exhibited two methane peaks one at maximum tillering stage and other at panicle initiation stage of the crop. Crop growth parameters such as leaf number, number of tillers and leaf area index (LAI) showed strong positive relationship with total methane flux. In both the experiments it was calculated that CH4 emission was substantially influenced by crop phenology and growth. This study emphasise the relationship of different growth parameters with methane emission. PMID:15894053

  8. Soil moisture affects fatty acids and oil quality parameters in peanut

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Drought affects yield of peanut, but its effect on oleic and linoleic acids that influence its oil quality of peanut genotypes with different levels of drought resistance has not been clearly investigated. Therefore, the aims of this research were to determine whether soil water levels could affect...

  9. Parameters affecting microwave-assisted extraction of organophosphorus pesticides from agricultural soil.

    PubMed

    Fuentes, Edwar; Báez, María E; Labra, Ronnie

    2007-10-26

    This work describes an optimised method for the determination of six representative organophosphorus pesticides (OPPs) (diazinon, parathion, methyl pirimiphos, methyl parathion, ethoprophos, and fenitrothion) in agricultural soils. The method is based on microwave-assisted extraction using a water-methanol modified mixture for desorption and simultaneous partitioning on n-hexane (MAEP), together with gas chromatography-flame photometric detection (GC-FPD). To improve GC-FPD signals (peak intensity and shape) olive oil was used effectively as a "matrix mimic". The optimisation of the extraction method was achieved in two steps: an initial approach through experimental design and principal component analysis where recovery of compounds using a water-methanol mixture ranged from 54 to 77%, and the second one by studying the addition of KH2PO4 to the extracting solution where recoveries were significantly increased, molecular replacing of OPPs from adsorption sites by phosphate being the probable extraction mechanism. Under optimised conditions, recoveries of pesticides from different soils were higher than 73%, except for methyl parathion in some soils, with SD equal or lower than 11% and detection limits ranging from 0.004 to 0.012 microg g(-1). The proposed method was used to determine OPPs in soil samples from different agricultural zones of Chile.

  10. Influence of Cacao Genotypes on Soil Rhizosphere Biological Parameters Under Agro Forestry System

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Interactions of management systems and cacao genotypes have profound influence on the diversity of soil micro-fauna in the rhizosphere; and such changes may provide benefits to plant growth and development. Field experiment was established at Tarapoto, Peru during 2004 with 60 cacao genotypes in an ...

  11. [Light response of Wisteria sinensis leaves physiological parameters under different soil moisture conditions].

    PubMed

    Xia, Jiang-bao; Zhang, Guang-can; Liu, Gang; Han, Wei; Chen, Jian; Liu, Xia

    2007-01-01

    With two years old Wisteria sinensis as test material, this paper measured the light response of its leaves net photosynthetic rate (Pn), transpiration rate (Tr) and water use efficiency (WUE) under different soil moisture conditions, aimed to ascertain the optimal soil moisture and light conditions of W. sinensis growth. The results showed that the Pn, Tr and WUE had evident threshold responses to the variations of soil moisture and light intensity. To maintain the normal growth and higher levels P. and WUE of W. sinensis, soil volumetric moisture content (Wr) and relative moisture content (Wv) should be within the range of 15.3%-26.5% and 46.4%-80.3%, and the optimal Wv and Wr were 23.3% and 70.6%, respectively. W. sineasis leaves had stronger adaptability to light conditions. When the photosynthetic active radiation (PAR) was 600-1600 micromol x m(-2) x s(-1), the Pn and WUE were at higher level, and the light saturation points of Pn and WUE were all at about 800-1000 x micromol x m(-2) x s(-1). The appearance of non-stomatal limit was significantly correlated with soil moisture and light intensity. When W, ranged from 18.4% to 26.5%, the decline of Pn was mainly caused by stomatal limit rather than PAR. Out of this range, Pn was obviously affected by PAR, and the critical turning point of PAR was observed with the change from stomatal limit to non-stomatal limit. The minimal values of Wv and Wr for the normal growth of W. sinensis were 11.9% and 36.1%, respectively, and the maximal PAR was 1000 micromol x m(-2) x s(-1), the critical point of detriment in leaf photosynthetic organ.

  12. THE EFFECT OF P-NITROCHLOROBENZENE ON HOMEOSTASIS QUANTITATIVE PARAMETERS OF KARST CAVE CLAYS AND ECUADOR SOILS MICROBIAL COMMUNITIES.

    PubMed

    Tashyrev, O B; Suslova, O S; Rokitko, P V

    2015-01-01

    In this paper it was given the effect of p-nitrochlorobenzene (NCB) on the homeostasis quantitative parameters of cave clays microbial communities from Western Ukraine and Abkhazia (Mushkarova Yama, Kuybushevskaya) and soils of Ecuador tropical ecosystems. For these microbial communities were determined maximum permissible concentrations and types of responses on xenobiotic. Microbial communities of Mushkarova Yama cave clays and rainforest soils of Ecuador were characterized by the first type of response. Microbial communities of Kuybushevskaya clays and mountain jungles of Ecuador were characterized by the second type of response. Maximum permissible concentration of NCB for Mushkarova Yama was 200 mg/l, for the other studied microbial communities--300 mg/l. It was shown, that microbial communities were not only highly resistant to NCB but also interacted with it by destroying this xenobiotic and decreasing its concentration in 4 times. PMID:26422923

  13. Inferring Land Surface Model Parameters for the Assimilation of Satellite-Based L-Band Brightness Temperature Observations into a Soil Moisture Analysis System

    NASA Technical Reports Server (NTRS)

    Reichle, Rolf H.; De Lannoy, Gabrielle J. M.

    2012-01-01

    The Soil Moisture and Ocean Salinity (SMOS) satellite mission provides global measurements of L-band brightness temperatures at horizontal and vertical polarization and a variety of incidence angles that are sensitive to moisture and temperature conditions in the top few centimeters of the soil. These L-band observations can therefore be assimilated into a land surface model to obtain surface and root zone soil moisture estimates. As part of the observation operator, such an assimilation system requires a radiative transfer model (RTM) that converts geophysical fields (including soil moisture and soil temperature) into modeled L-band brightness temperatures. At the global scale, the RTM parameters and the climatological soil moisture conditions are still poorly known. Using look-up tables from the literature to estimate the RTM parameters usually results in modeled L-band brightness temperatures that are strongly biased against the SMOS observations, with biases varying regionally and seasonally. Such biases must be addressed within the land data assimilation system. In this presentation, the estimation of the RTM parameters is discussed for the NASA GEOS-5 land data assimilation system, which is based on the ensemble Kalman filter (EnKF) and the Catchment land surface model. In the GEOS-5 land data assimilation system, soil moisture and brightness temperature biases are addressed in three stages. First, the global soil properties and soil hydraulic parameters that are used in the Catchment model were revised to minimize the bias in the modeled soil moisture, as verified against available in situ soil moisture measurements. Second, key parameters of the "tau-omega" RTM were calibrated prior to data assimilation using an objective function that minimizes the climatological differences between the modeled L-band brightness temperatures and the corresponding SMOS observations. Calibrated parameters include soil roughness parameters, vegetation structure parameters

  14. Parameters describing nonequilibrium transport of polycyclic aromatic hydrocarbons through contaminated soil columns: estimability analysis, correlation, and optimization.

    PubMed

    Ngo, Viet V; Michel, Julien; Gujisaite, Valérie; Latifi, Abderrazak; Simonnot, Marie-Odile

    2014-03-01

    The soil and groundwater at former industrial sites polluted by polycyclic aromatic hydrocarbons (PAHs) produce a very challenging environmental issue. The description of PAH transport by means of mathematical models is therefore needed for risk assessment and remediation strategies at these sites. Due to the complexity of release kinetics and transport behavior of the PAHs in the aged contaminated soils, their transport is usually evaluated at the laboratory scale. Transport parameters are then estimated from the experimental data via the inverse method. To better assess the uncertainty of optimized parameters, an estimability method was applied to firstly investigate the information content of experimental data and the possible correlations among parameters in the two-site sorption model. These works were based on the concentrations of three PAHs, Acenaphthene (ACE), Fluoranthene (FLA) and Pyrene (PYR), in the leaching solutions of the experiments under saturated and unsaturated flow conditions. The estimability results showed that the experiment under unsaturated flow conditions contained more information content for estimating four transport parameters than under the saturated one. In addition, whatever the experimental conditions for all three PAHs the fraction of sites with instantaneous sorption, f, was highly correlated with the adsorption distribution coefficient, Kd. The very strong correlation between the two parameters f and Kd suggests that they should not be simultaneously calibrated. Transport parameters were optimized using HYDRUS-1D software with different scenarios based on the estimability analysis results. The optimization results were not always reliable, especially in the case of the experiment under saturated flow conditions because of its low information content. In addition, the estimation of transport parameters became very uncertain if two parameters f and Kd were optimized simultaneously. The findings of the current work can suggest some

  15. Combined Borehole Seismic and Electromagnetic Inversion For High-Resolution Petrophysical Assessment Of Hydocarbon Reservoirs

    SciTech Connect

    Carlos Torres-Verdin; G. Michael Hoversten; Ki Ha Lee; Gregory Newman; Kurt Nihei

    2008-12-31

    This report summarizes the work performed between January 2005 and December 2007, under DOE research contract DE-FC26-04NT15507. The project is was performed by the Center for Petroleum and Geosystems Engineering of The University of Texas at Austin and Lawrence Berkeley National Laboratory under the auspices of the National Energy Technology Office (NETL) and the Strategic Center for Natural Gas and Oil (SCNGO). During the three-year project, we developed new methods to combine borehole sonic and electromagnetic (EM) measurements for the improved assessment of elastic and petrophysical properties of rock formations penetrated by a well. Sonic measurements consisted of full waveform acoustic amplitudes acquired with monopole and dipole sources, whereas EM measurements consisted of frequency-domain voltages acquired with multi-coil induction systems. The combination of sonic and EM measurements permitted the joint estimation of elastic and petrophysical properties in the presence of mud-filtrate invasion. It was conclusively shown that the combined interpretation of sonic and EM measurements reduced non-uniqueness in the estimation of elastic and petrophysical properties and improved the spatial resolution of the estimations compared to estimations yielded separately from the two types of measurements. Moreover, this approach enabled the assessment of dynamic petrophysical properties such as permeability, as it incorporated the physics of mud-filtrate invasion in the interpretation of the measurements. The first part of the project considered the development of fast and reliable numerical algorithms to simulate borehole sonic waveforms in 2D, 3D, and radial 1D media. Such algorithms were subsequently used in the quantitative estimation of elastic properties jointly from borehole sonic and EM measurements. In the second part of the project we developed a new algorithm to estimate water saturation, porosity, and dry-rock elastic moduli jointly from borehole sonic and

  16. Microbial community composition and enzyme activities in cryoturbated arctic soils are controlled by environmental parameters rather than by soil organic matter properties

    NASA Astrophysics Data System (ADS)

    Schnecker, Jörg; Wild, Birgit; Hofhansl, Florian; Eloy Alves, Ricardo J.; Bárta, Jiří; Čapek, Petr; Fuchslueger, Lucia; Gentsch, Norman; Gittel, Antje; Guggenberger, Georg; Lashchinskiy, Nikolay; Mikutta, Robert; Šantrůčková, Hana; Shibistova, Olga; Knoltsch, Anna; Takriti, Mounir; Urich, Tim; Richter, Andreas

    2014-05-01

    Enzyme-mediated decomposition of soil organic matter (SOM) is controlled by environmental parameters (i.e. temperature, moisture, pH) and organic matter properties. The role of these factors as well as the role of microbial community composition and therefore the main drivers of enzymatic decomposition of SOM are largely unknown, since all of these factors are often intercorrelated. We investigated soils from three regions in the Siberian Arctic, where carbon rich topsoil material has been incorporated into the subsoil (cryoturbation). We took advantage of this combination of topsoil organic matter and subsoil environmental conditions, to identify controls on microbial community composition and enzyme activities. We found that microbial community composition (estimated by phospholipid fatty acids analysis), was similar in cryoturbated OM and in surrounding subsoil, although C and N content were similar in cryoturbated material and topsoils. These results suggest that physical conditions rather than SOM properties shaped microbial community composition. To identify direct and indirect drivers of extracellular enzyme activities (cellobiohydrolase, leucine-amino-peptidase and phenoloxidase) we included microbial community composition, C, N and clay content, as well as pH in structural equation models. Models for regular horizons (excluding cryoturbated material), showed that enzyme activities were mainly controlled by C or N. Microbial community composition had no effect. In contrast models for cryoturbated OM, where the microbial community was adapted to subsoil environmental conditions, showed that enzyme activities were also related to microbial community composition. This indicates enzyme activities and more general decomposition to be limited by microbial community composition in cryoturbated organic matter, rather than by the availability of the substrates. The controlling cascade of physical parameters over microbial community composition to enzyme activities

  17. Three-parameter modeling of the soil sorption of acetanilide and triazine herbicide derivatives.

    PubMed

    Freitas, Mirlaine R; Matias, Stella V B G; Macedo, Renato L G; Freitas, Matheus P; Venturin, Nelson

    2014-02-01

    Herbicides have widely variable toxicity and many of them are persistent soil contaminants. Acetanilide and triazine family of herbicides have widespread use, but increasing interest for the development of new herbicides has been rising to increase their effectiveness and to diminish environmental hazard. The environmental risk of new herbicides can be accessed by estimating their soil sorption (logKoc), which is usually correlated to the octanol/water partition coefficient (logKow). However, earlier findings have shown that this correlation is not valid for some acetanilide and triazine herbicides. Thus, easily accessible quantitative structure-property relationship models are required to predict logKoc of analogues of the these compounds. Octanol/water partition coefficient, molecular weight and volume were calculated and then regressed against logKoc for two series of acetanilide and triazine herbicides using multiple linear regression, resulting in predictive and validated models. PMID:24374777

  18. Impact of PAH on biological health parameters of soils of an Indian refinery and adjoining agricultural area--a case study.

    PubMed

    Chaudhary, Priyanka; Singh, Shashi Bala; Chaudhry, Smita; Nain, Lata

    2012-01-01

    The present study is aimed at analysing and comparing different soil enzymes in soil samples of native contaminated sites of a Mathura refinery and adjoining agricultural land. Enzyme activities are considered as indicators of soil quality and changes in biogeochemical function due to management or perturbations. Soil samples were collected from the premises and nearby area of Mathura refinery, India. Biological health parameters (dehydrogenase, aryl esterase, aryl sulphatase, [Formula: see text]-glucosidase, alkaline phosphatase, acid phosphatase, lipase, laccase and catalase activity) were estimated in the soil samples. Among all the samples, sewage sludge soil showed maximum activity of enzymes, microbial biomass carbon and most probable number of polycyclic aromatic hydrocarbon (PAH) degraders in soils spiked with three- to four-ring PAHs at 50 ppm. Available phosphorus, potassium and nitrogen was also exceptionally high in this sample, indicating maximum microbial bioconversion due to presence of nutrients stimulating potent PAH-degrading microorganisms.

  19. A coupled soil-vegatition scheme: Description, parameters, validation, and sensitivity studies

    SciTech Connect

    Acs, F.

    1994-02-01

    A coupled soil-vegetation scheme is presented. A one-layer canopy and a three-layer soil representation is used. The impact of canopy morphological properties on radiation and momentum transfer in the vegetation is modeled as simply as possible. The impact of plant physiology on water transport through the vegetation layer is elaborated on in detail. The canopy resistance is calculated as the product of the fractional relative stomatal conductances of different governing factors. The scheme is tested using point micrometeorological and biophysical data. It is shown that the agreement between simulated and measured turbulent fluxes is fairly good. Some sensitivity analyses are also made. The sensitivity of latent and sensible heat flux distribution is investigated with respect to the variations in the leaf drag coefficient c{sub d}, the root density in the soil surface layer R{sub des}, and various formulations of the relative stomatal conductance for expressing the effect of vegetation moisture availability F(vm).

  20. Extraction parameters significantly influence the quantity and the profile of PLFAs extracted from soils.

    PubMed

    Papadopoulou, Evagelia S; Karpouzas, Dimitrios G; Menkissoglu-Spiroudi, Urania

    2011-10-01

    Phospholipid fatty acid (PLFA) analysis is a robust method for characterizing soil microbial communities. We determined the effects of extraction solvent (chloroform vs dichloromethane) and buffer (phosphate vs citrate) on the yield and the profile of PLFAs extracted from an acidic (pH 5.5) and an alkaline (pH 8.6) soil following two 2-h sequential extractions. The yield and the profile of the PLFAs obtained separately by the first and the second 2-h extraction were compared to identify the impact of sequential extractions on the PLFA extraction efficiency. Chloroform-citrate and a 2 × 2-h extraction maximized PLFA yields in both soils. Multivariate analysis of the data showed that the choice of the extraction mixture did not significantly influence the profile of the PLFAs obtained by the first 2-h extraction, whereas it had a profound effect on the profile of the PLFAs obtained by the second 2-h extraction. Most PLFAs were extracted during the first extraction except 18:2ω6,9 and 22:0 which were almost equally extracted by the two sequential extractions. The choice of organic solvent significantly influenced the profile of the PLFAs extracted; their yield increased with chloroform with the exception of 18:2ω6,9 and 22:0 which were favored by dichloromethane. Overall, a 2 × 2-h extraction with chloroform/methanol/citrate is expected to provide maximum PLFA yields. PMID:21556882

  1. The influence of soil organic carbon on interactions between microbial parameters and metal concentrations at a long-term contaminated site.

    PubMed

    Muhlbachova, G; Sagova-Mareckova, M; Omelka, M; Szakova, J; Tlustos, P

    2015-01-01

    The effects of lead, zinc, cadmium, arsenic and copper deposits on soil microbial parameters were investigated at a site exposed to contamination for over 200 years. Soil samples were collected in triplicates at 121 sites differing in contamination and soil organic carbon (SOC). Microbial biomass, respiration, dehydrogenase activity and metabolic quotient were determined and correlated with total and extractable metal concentrations in soil. The goal was to analyze complex interactions between toxic metals and microbial parameters by assessing the effect of soil organic carbon in the relationships. The effect of SOC was significant in all interactions and changed the correlations between microbial parameters and metal fractions from negative to positive. In some cases, the effect of SOC was combined with that of clay and soil pH. In the final analysis, dehydrogenase activity was negatively correlated to total metal concentrations and acetic acid extractable metals, respiration and metabolic quotient were to ammonium nitrate extractable metals. Dehydrogenase activity was the most sensitive microbial parameter correlating most frequently with contamination. Total and extractable zinc was most often correlated with microbial parameters. The large data set enabled robust explanation of discrepancies in organic matter functioning occurring frequently in analyzing of contaminated soil processes.

  2. Mechanical and petrophysical study of fractured shale materials

    NASA Astrophysics Data System (ADS)

    Bonnelye, A.; Schubnel, A.; David, C.; Henry, P.; Guglielmi, Y.; Gout, C.; Dick, P.

    2015-12-01

    Mechanical and physical properties of shales are of major importance for upper crustal fault hydro-mechanical behavior. In particular, relationships between applied stress, textural anisotropy and transport properties. These relations can be investigated in the laboratory and here, was used shales from Tournemire (southern France). Triaxial tests were performed in order to determine the elasto-plastic yield envelope on 3 sets of samples with 3various bedding orientations (0°, 45°, and 90°). For each set, experiments were carried out at increasing confining pressures (2.5, 5, 10, 20, 40, 80MPa). They were performed under nominally drained conditions, at strain rates ranging between 5x10-7 s-1 - 1x10-5 s-1up to failure. During each experiment, P and S wave elastic velocities were continuously measured, in order to monitor the evolution of elastic anisotropy. Results show that the orientation of principal stress relative to bedding plays an important role on the brittle strength. Minimum strength is observed for samples deformed at 45° to bedding. Strength anisotropy increases both with confining pressure and strain rate. We interpret this result as the cohesive strength (and fracture toughness) being strain rate dependent. Although brittle failure and stress drops were systematically observed, deformation remained aseismic. This confirms that shales are good lithological candidates for shallow aseismic creep and slow slip events. Brittle failure was preceded by the development of P wave anisotropy, due to both crack growth and mineral re-orientation. Anisotropy variations were largest for samples deformed perpendicular to bedding, at the onset of rupture. Anisotropy reversal was observed at the highest confining pressures. For samples deformed parallel to bedding, the P wave anisotropy development is weaker. For both of these orientations, Thomsens parameters were inverted from the elastic wave data in order to quantify the evolution of elastic anisotropy. We

  3. Effects of diagenesis on pore texture and petrophysical properties of sandstone reservior and its geological significance

    SciTech Connect

    Zhu, G.

    1982-01-01

    This paper deals with diagenesis of Yan-10 Sandstones, Yanan Series, jurassic-the main producing horizons in an exploratory area in Shan-Gan-Ning Basin, China. The effects of diagenesis on pore texture and petrophysical porperties of sandstones, its effects on forming trapping conditions for oil pools, the genesis of low permeability zone near the oil-water boundary, as well as secondary pores together with authigenic clay minerals of sandstones are presented. Furthermore, the paper describes briefly Yan-10 Sandstones in some other areas. 11 refs.

  4. INTEGRATED APPROACH FOR THE PETROPHYSICAL INTERPRETATION OF POST- AND PRE-STACK 3-D SEISMIC DATA, WELL-LOG DATA, CORE DATA, GEOLOGICAL INFORMATION AND RESERVOIR PRODUCTION DATA VIA BAYESIAN STOCHASTIC INVERSION

    SciTech Connect

    Carlos Torres-Verdin; Mrinal K. Sen

    2004-03-01

    The present report summarizes the work carried out between September 30, 2002 and August 30, 2003 under DOE research contract No. DE-FC26-00BC15305. During the third year of work for this project we focused primarily on improving the efficiency of inversion algorithms and on developing algorithms for direct estimation of petrophysical parameters. The full waveform inversion algorithm for elastic property estimation was tested rigorously on a personal computer cluster. For sixteen nodes on the cluster the parallel algorithm was found to be scalable with a near linear speedup. This enabled us to invert a 2D seismic line in less than five hours of CPU time. We were invited to write a paper on our results that was subsequently accepted for publication. We also carried out a rigorous study to examine the sensitivity and resolution of seismic data to petrophysical parameters. In other words, we developed a full waveform inversion algorithm that estimates petrophysical parameters such as porosity and saturation from pre-stack seismic waveform data. First we used a modified Biot-Gassmann equation to relate petrophysical parameters to elastic parameters. The transformation was validated with a suite of well logs acquired in the deepwater Gulf of Mexico. As a part of this study, we carried out a sensitivity analysis and found that the porosity is very well resolved while the fluid saturation remains insensitive to seismic wave amplitudes. Finally we conducted a joint inversion of pre-stack seismic waveform and production history data. To overcome the computational difficulties we used a simpler waveform modeling algorithm together with an efficient subspace approach. The algorithm was tested on a realistic synthetic data set. We observed that the use of pre-stack seismic data helps tremendously to improve horizontal resolution of porosity maps. Finally, we submitted four publications to refereed technical journals, two refereed extended abstracts to technical conferences

  5. Petrophysical characterization of first ever drilled core samples from an active CO2 storage site, the German Ketzin Pilot Site - Comparison with long term experiments

    NASA Astrophysics Data System (ADS)

    Zemke, Kornelia; Liebscher, Axel

    2014-05-01

    Petrophysical properties like porosity and permeability are key parameters for a safe long-term storage of CO2 but also for the injection operation itself. These parameters may change during and/or after the CO2 injection due to geochemical reactions in the reservoir system that are triggered by the injected CO2. Here we present petrophysical data of first ever drilled cores from a newly drilled well at the active CO2 storage site - the Ketzin pilot site in the Federal State of Brandenburg, Germany. By comparison with pre-injection baseline data from core samples recovered prior to injection, the new samples provide the unique opportunity to evaluate the impact of CO2 on pore size related properties of reservoir and cap rocks at a real injection site under in-situ reservoir conditions. After injection of 61 000 tons CO2, an additional well was drilled and new rock cores were recovered. In total 100 core samples from the reservoir and the overlaying caprock were investigated by NMR relaxation. Permeability of 20 core samples was estimated by nitrogen and porosity by helium pycnometry. The determined data are comparable between pre-injection and post-injection core samples. The lower part of the reservoir sandstone is unaffected by the injected CO2. The upper part of the reservoir sandstone shows consistently slightly lower NMR porosity and permeability values in the post-injection samples when compared to the pre-injection data. This upper sandstone part is above the fluid level and CO2 present as a free gas phase and a possible residual gas saturation of the cores distorted the NMR results. The potash-containing drilling fluid can also influence these results: NMR investigation of twin samples from inner and outer parts of the cores show a reduced fraction of larger pores for the outer core samples together with lower porosities and T2 times. The drill mud penetration depth can be controlled by the added fluorescent tracer. Due to the heterogeneous character of the

  6. Savanna domain in the herbivores-fire parameter space exploiting a tree-grass-soil water dynamic model.

    PubMed

    De Michele, C; Accatino, F; Vezzoli, R; Scholes, R J

    2011-11-21

    The tree-grass co-existence in savannas involves multiple and sometimes connected biogeophysical conditions. The savanna domain, its boundaries, and transitions (gradual or abrupt) to other vegetation types (i.e., grassland or forest) are fundamental for the management of ecosystems and for preserving the biodiversity in present conditions and in future changing scenarios. Here we investigate the savanna domain within grazers-fire and browsers-fire parameter planes through a simple ecohydrological model of tree-grass-soil water dynamics. Stability maps allow to identify savanna domains and to show the behavior of vegetation under increasing pressure of grazing and browsing. Stability maps shed light on the causes behind possible vegetation abrupt transitions (e.g., forest collapse and bush encroachment). An application to 15 African savannas sites is presented and discussed with the support of a local sensitivity analysis of the model's parameters. PMID:21875600

  7. Application of uniaxial confining-core clamp with hydrous pyrolysis in petrophysical and geochemical studies of source rocks at various thermal maturities

    USGS Publications Warehouse

    Lewan, Michael D.; Birdwell, Justin E.; Baez, Luis; Beeney, Ken; Sonnenberg, Steve

    2013-01-01

    Understanding changes in petrophysical and geochemical parameters during source rock thermal maturation is a critical component in evaluating source-rock petroleum accumulations. Natural core data are preferred, but obtaining cores that represent the same facies of a source rock at different thermal maturities is seldom possible. An alternative approach is to induce thermal maturity changes by laboratory pyrolysis on aliquots of a source-rock sample of a given facies of interest. Hydrous pyrolysis is an effective way to induce thermal maturity on source-rock cores and provide expelled oils that are similar in composition to natural crude oils. However, net-volume increases during bitumen and oil generation result in expanded cores due to opening of bedding-plane partings. Although meaningful geochemical measurements on expanded, recovered cores are possible, the utility of the core for measuring petrophysical properties relevant to natural subsurface cores is not suitable. This problem created during hydrous pyrolysis is alleviated by using a stainless steel uniaxial confinement clamp on rock cores cut perpendicular to bedding fabric. The clamp prevents expansion just as overburden does during natural petroleum formation in the subsurface. As a result, intact cores can be recovered at various thermal maturities for the measurement of petrophysical properties as well as for geochemical analyses. This approach has been applied to 1.7-inch diameter cores taken perpendicular to the bedding fabric of a 2.3- to 2.4-inch thick slab of Mahogany oil shale from the Eocene Green River Formation. Cores were subjected to hydrous pyrolysis at 360 °C for 72 h, which represents near maximum oil generation. One core was heated unconfined and the other was heated in the uniaxial confinement clamp. The unconfined core developed open tensile fractures parallel to the bedding fabric that result in a 38 % vertical expansion of the core. These open fractures did not occur in the

  8. Synergy between optical and microwave remote sensing to derive soil and vegetation parameters from MAC Europe 1991 Experiment

    NASA Technical Reports Server (NTRS)

    Taconet, O.; Benallegue, M.; Vidal, A.; Vidal-Madjar, D.; Prevot, L.; Normand, M.

    1993-01-01

    The ability of remote sensing for monitoring vegetation density and soil moisture for agricultural applications is extensively studied. In optical bands, vegetation indices (NDVI, WDVI) in visible and near infrared reflectances are related to biophysical quantities as the leaf area index, the biomass. In active microwave bands, the quantitative assessment of crop parameters and soil moisture over agricultural areas by radar multiconfiguration algorithms remains prospective. Furthermore the main results are mostly validated on small test sites, but have still to be demonstrated in an operational way at a regional scale. In this study, a large data set of radar backscattering has been achieved at a regional scale on a French pilot watershed, the Orgeval, along two growing seasons in 1988 and 1989 (mainly wheat and corn). The radar backscattering was provided by the airborne scatterometer ERASME, designed at CRPE, (C and X bands and HH and VV polarizations). Empirical relationships to estimate water crop and soil moisture over wheat in CHH band under actual field conditions and at a watershed scale are investigated. Therefore, the algorithms developed in CHH band are applied for mapping the surface conditions over wheat fields using the AIRSAR and TMS images collected during the MAC EUROPE 1991 experiment. The synergy between optical and microwave bands is analyzed.

  9. Estimating the dual-enzyme kinetic parameters for Cr (VI) reduction by Shewanella oneidensis MR-1 from soil column experiments.

    PubMed

    Hossain, Md Akram; Alam, Mahbub; Yonge, David R

    2005-09-01

    Hexavalent chromium (Cr (VI)) contamination of soil and groundwater is considered a major environmental concern. Bioreduction of Cr (VI) to trivalent chromium (Cr (III)) can be considered an effective technology in remediating Cr (VI) contaminated sites. Among the Cr (VI) reducing bacteria, Shewanella oneidensis MR-1 (MR-1) is relatively effective. Reduction of Cr (VI) by MR-1 is defined by the dual-enzyme kinetic model. The feasibility of bioreduction of Cr (VI) is usually evaluated by performing batch experiments which may not accurately represent the subsurface environment. The objective of this paper is to present a rational approach to determine the dual-enzyme reaction kinetics of Cr (VI) reduction by MR-1 from continuous flow soil column experiments which more accurately simulate the subsurface environment. Kinetic parameters obtained from soil column data were found to be much smaller than that obtained from batch data. The stable enzyme induced reaction rate was found to be 127th and the average deactivating enzyme induced reaction rate was 117th of the corresponding values obtained from batch reactor data as reported in literature.

  10. Evaluation of biochemical and redox parameters in rats fed with corn grown in soil amended with urban sewage sludge.

    PubMed

    Grotto, Denise; Carneiro, Maria Fernanda Hornos; Sauer, Elisa; Garcia, Solange Cristina; de Melo, Wanderley José; Barbosa, Fernando

    2013-09-01

    The increased production of urban sewage sludge requires alternative methods for final disposal. A very promising choice is the use of sewage sludge as a fertilizer in agriculture, since it is rich in organic matter, macro and micronutrients. However, urban sewage sludge may contain toxic substances that may cause deleterious effects on the biota, water and soil, and consequently on humans. There is a lack of studies evaluating how safe the consumption of food cultivated in soils containing urban sewage sludge is. Thus, the aim of this paper was to evaluate biochemical and redox parameters in rats fed with corn produced in a soil treated with urban sewage sludge for a long term. For these experiments, maize plants were grown in soil amended with sewage sludge (rates of 5, 10 and 20 t/ha) or not (control). Four different diets were prepared with the corn grains produced in the field experiment, and rats were fed with these diets for 1, 2, 4, 8 and 12 weeks. Biochemical parameters (glucose, total cholesterol and fractions, triglycerides, aspartate aminotransferase and alanine aminotransferase) as well the redox state biomarkers such as reduced glutathione (GSH), malondialdehyde (MDA), catalase, glutathione peroxidase and butyrylcholinesterase (BuChE) were assessed. Our results show no differences in the biomarkers over 1 or 2 weeks. However, at 4 weeks BuChE activity was inhibited in rats fed with corn grown in soil amended with sewage sludge (5, 10 and 20 t/ha), while MDA levels increased. Furthermore, prolonged exposure to corn cultivated in the highest amount per hectare of sewage sludge (8 and 12 weeks) was associated with an increase in MDA levels and a decrease in GSH levels, respectively. Our findings add new evidence of the risks of consuming food grown with urban sewage sludge. However, considering that the amount and type of toxic substances present in urban sewage sludge varies considerably among different sampling areas, further studies are needed to

  11. Uncertainty in the determination of soil hydraulic parameters and its influence on the performance of two hydrological models of different complexity

    NASA Astrophysics Data System (ADS)

    Baroni, G.; Facchi, A.; Gandolfi, C.; Ortuani, B.; Horeschi, D.; van Dam, J. C.

    2010-02-01

    Data of soil hydraulic properties forms often a limiting factor in unsaturated zone modelling, especially at the larger scales. Investigations for the hydraulic characterization of soils are time-consuming and costly, and the accuracy of the results obtained by the different methodologies is still debated. However, we may wonder how the uncertainty in soil hydraulic parameters relates to the uncertainty of the selected modelling approach. We performed an intensive monitoring study during the cropping season of a 10 ha maize field in Northern Italy. The data were used to: i) compare different methods for determining soil hydraulic parameters and ii) evaluate the effect of the uncertainty in these parameters on different variables (i.e. evapotranspiration, average water content in the root zone, flux at the bottom boundary of the root zone) simulated by two hydrological models of different complexity: SWAP, a widely used model of soil moisture dynamics in unsaturated soils based on Richards equation, and ALHyMUS, a conceptual model of the same dynamics based on a reservoir cascade scheme. We employed five direct and indirect methods to determine soil hydraulic parameters for each horizon of the experimental profile. Two methods were based on a parameter optimization of: a) laboratory measured retention and hydraulic conductivity data and b) field measured retention and hydraulic conductivity data. The remaining three methods were based on the application of widely used Pedo-Transfer Functions: c) Rawls and Brakensiek, d) HYPRES, and e) ROSETTA. Simulations were performed using meteorological, irrigation and crop data measured at the experimental site during the period June - October 2006. Results showed a wide range of soil hydraulic parameter values generated with the different methods, especially for the saturated hydraulic conductivity Ksat and the shape parameter α of the van Genuchten curve. This is reflected in a variability of the modeling results which is

  12. Simulating aerosols over Arabian Peninsula with CHIMERE: Sensitivity to soil, surface parameters and anthropogenic emission inventories

    NASA Astrophysics Data System (ADS)

    Beegum, S. Naseema; Gherboudj, Imen; Chaouch, Naira; Couvidat, Florian; Menut, Laurent; Ghedira, Hosni

    2016-03-01

    A three dimensional chemistry transport model, CHIMERE, was used to simulate the aerosol optical depths (AOD) over the Arabian Peninsula desert with an offline coupling of Weather Research and Forecasting (WRF) model. The simulations were undertaken with: (i) different horizontal and vertical configurations, (ii) new datasets derived for soil/surface properties, and (iii) EDGAR-HTAP anthropogenic emissions inventories. The model performance evaluations were assessed: (i) qualitatively using MODIS (Moderate-Resolution Imaging Spectroradiometer) deep blue (DB) AOD data for the two local dust events of August 6th and 23rd (2013), and (ii) quantitatively using AERONET (Aerosol Robotic Network) AOD observations, CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation) aerosol extinction profiles, and AOD simulations from various forecast models. The model results were observed to be highly sensitive to erodibility and aerodynamic surface roughness length. The use of new datasets on soil erodibility, derived from the MODIS reflectance, and aerodynamic surface roughness length (z0), derived from the ERA-Interim datasets, significantly improved the simulation results. Simulations with the global EDGAR-HTAP anthropogenic emission inventories brought the simulated AOD values closer to the observations. Performance testing of the adapted model for the Arabian Peninsula domain with improved datasets showed good agreement between AERONET AOD measurements and CHIMERE simulations, where the correlation coefficient (R) is 0.6. Higher values of the correlation coefficients and slopes were observed for the dusty periods compared to the non-dusty periods.

  13. Petrophysical characterization of the Carito Norte, Mulata and Carito fields, Norte de Monagas, Eastern Venezuela

    SciTech Connect

    Porras, J.C.; De J. Valle,

    1996-08-01

    The Norte de Monagas trend is located in the Eastern Venezuelan Basin and is characterized by high temperature, high initial pressure and production rates, variable PVT properties, GORs, and asphaltene content, and the presence of a tar mat at the base of the oil column. These reservoirs were petrophysically characterized through the integration of core and log data. Productive sands are composed of very coarse- to medium-grained sands deposited primarily in deltaic to shallow marine environments. These sands are quartz-rich, with clay matrix averaging 3% in the Oligocene and 6% in the Cretaceous. The main difference is the presence of up to 30% feldspars in the Cretaceous. Clay mineralogy is dominated by illitic material in the Cretaceous and by kaolinite in the Oligocene. Post-depositional changes dominated by cementation, mechanical compaction and subsequent dissolution processes have resulted in marked improvement or degradation of the productive characteristics of these reservoirs. Rocks were divided into four petrophysical. categories based on grain size, pore throat radius, porosity and permeability. Mercury saturation vs. mercury saturation over capillary pressure plots show the dominant interconnected pore system which controls flow rates is best defined by 50% saturation. Plots constructed using R50 pore aperture correlation indicate the pore throats to be macro to mega porous. Average log calculated water saturation is 14% compared with estimated from capillary pressure data of 12% at 1200{prime} above free water level, and 15% from relative permeability data. Relative permeability data indicate the rocks behave preferably as water-wet.

  14. Borehole petrophysical chemostratigraphy of Pennsylvanian black shales in the Kansas subsurface

    USGS Publications Warehouse

    Doveton, J.H.; Merriam, D.F.

    2004-01-01

    Pennsylvanian black shales in Kansas have been studied on outcrop for decades as the core unit of the classic Midcontinent cyclothem. These shales appear to be highstand condensed sections in the sequence stratigraphic paradigm. Nuclear log suites provide several petrophysical measurements of rock chemistry that are a useful data source for chemostratigraphic studies of Pennsylvanian black shales in the subsurface. Spectral gamma-ray logs partition natural radioactivity between contributions by U, Th, and K sources. Elevated U contents in black shales can be related to reducing depositional environments, whereas the K and Th contents are indicators of clay-mineral abundance and composition. The photoelectric factor log measurement is a direct function of aggregate atomic number and so is affected by clay-mineral volume, clay-mineral iron content, and other black shale compositional elements. Neutron porosity curves are primarily a response to hydrogen content. Although good quality logs are available for many black shales, borehole washout features invalidate readings from the nuclear contact devices, whereas black shales thinner than tool resolution will be averaged with adjacent beds. Statistical analysis of nuclear log data between black shales in successive cyclothems allows systematic patterns of their chemical and petrophysical properties to be discriminated in both space and time. ?? 2004 Elsevier B.V. All rights reserved.

  15. Inverse estimation of the unsaturated soil hydraulic properties from tension disc infiltrometer data and electrical resistivity data

    NASA Astrophysics Data System (ADS)

    Schneider, S.; Swinnen, R.; Pessel, M.; Vanderborght, J.; Coquet, Y.; Vachier, P.

    2009-04-01

    An accurate and time-efficient estimation of unsaturated soil hydraulic properties in the field remains a challenge. Tension-infiltrometry is often used to determine unsaturated soil hydraulic conductivity and its spatial variability in the field. Due to capillary flow, a 3-D wetting bulb develops under the tension infiltrometer. The shape of the bulb depends mainly on the unsaturated soil hydraulic properties. In classical tension-infiltrometer experiments only the amount of infiltrated water is measured with time and used to infer soil hydraulic conductivity. Electrical resistivity tomography (ERT) offers the possibility to image the spatial distribution of bulk soil electrical conductivity from a set of apparent electrical resistivity (ER) measurements, which is related through a petrophysical model to the soil water content. Therefore, apparent ER data contain information about the 3-D structure of the wetting bulb, which may be exploited to infer soil hydraulic properties. Whether a combination of tension-infiltrometer and apparent ER data can be used to estimate soil hydraulic parameters was investigated in numerical experiments. Instead of using a tomographic inversion of the apparent ER data, i.e. ERTomography, to derive the spatial distribution of the wetting bulb from which subsequently hydraulic parameters are derived, we explore the potential of a joint inversion approach that derives hydraulic parameters directly from apparent ER data. The combined infiltration and apparent ER datasets showed that the soil hydraulic parameters could be inverted from a single infiltration experiment, which is not possible when only infiltration data are used for inversion. Application of the proposed method was performed on a silt clay loam. Results have shown accurate estimations on the saturated hydraulic conductivity and on the hydraulic parameters of the water retention curve.

  16. Evaluation on an original resistivity inversion method of water flooding a conglomerate reservoir based on petrophysical analysis

    NASA Astrophysics Data System (ADS)

    Liu, Renqiang; Duan, Yonggang; Tan, Fengqi; Wang, Guochang; Qin, Jianhua; Neupane, Bhupati

    2015-10-01

    An accurate inversion of original reservoir resistivity is an important problem for waterflood development in oilfields in the middle-late development period. This paper describes the theoretical model of original resistivity recovery for a conglomerate reservoir established by petrophysical models, based on the stratigraphic model of reservoir vertical invasion of the conglomerate reservoir of an oilfield. Likewise two influencing factors of the resistivity change with a water-flooded reservoir were analyzed. The first one is the clay volume decrease due to an injected water wash argillaceous particle and the reservoir resistivity changes are influenced by it, and the other is to inject water to displace crude oil in the pore space leading to the increase of the water-bearing volume. Moreover the conductive ions of the injected water and the original formation water exchange and balance because of their salinity difference, and the reservoir resistivity changes are also influenced by them. Through the analysis of the above influential factors based on the fine identification of conglomerate lithologies the inversion models of three variables, including changes in the amount of clay, the resistivity of the irreducible water and the increase of the water bearing volume, were established by core analysis data, production performance and well logging curves information, and accurately recovered the original reservoir resistivity of the conglomerate. The original oil saturation of the reservoir was calculated according to multiple linear regression models. Finally, the produced index is defined as the difference of the original oil saturation and current oil saturation to the original oil saturation ratio, and it eliminates the effects of conglomerate lithologies and heterogeneity for the quantitative evaluation of flooded layers by the use of the principle of relative value. Compared with traditional flooding sensitive parameters which are oil saturation and water

  17. Analysing the Information Content of Point Measurements of the Soil Hydraulic State Variables by Global Sensitivity Analysis and Multiobjective Parameter Estimation

    NASA Astrophysics Data System (ADS)

    Werisch, Stefan; Lennartz, Franz; Schütze, Niels

    2015-04-01

    Inverse modeling has become a common approach to infer the parameters of the water retention and hydraulic conductivity functions from observations of the vadose zone state variables during dynamic experiments under varying boundary conditions. This study focuses on the estimation and investigation of the feasibility of effective soil hydraulic properties to describe the soil water flow in an undisturbed 1m³ lysimeter. The lysimeter is equipped with 6 one-dimensional observation arrays consisting of 4 tensiometers and 4 water content probes each, leading to 6 replicated one-dimensional observations which establish the calibration data base. Methods of global sensitivity analysis and multiobjective calibration strategies have been applied to examine the information content about the soil hydraulic parameters of the Mualem-van Genuchten (MvG) model contained in the individual data sets, to assess the tradeoffs between the different calibration data sets and to infer effective soil hydraulic properties for each of the arrays. The results show that (1) information about the MvG model parameters decreases with increasing depth, due to effects of overlapping soil layers and reduced soil water dynamics, (2) parameter uncertainty is affected by correlation between the individual parameters. Despite these difficulties, (3) effective one-dimensional parameter sets, which produce satisfying fits and have acceptable trade-offs, can be identified for all arrays, but (4) the array specific parameter sets vary significantly and cannot be transferred to simulate the water flow in other arrays, and (5) none of the parameter sets is suitable to simulate the integral water flow within the lysimeter. The results of the study challenge the feasibility of the inversely estimated soil hydraulic properties from multiple point measurements of the soil hydraulic state variables. Relying only on point measurements inverse modeling can lead to promising results regarding the observations

  18. Analysing the Information Content of Point Measurements of the Vadose Zone State Variables for the Inverse Estimation of Soil Hydraulic Parameters

    NASA Astrophysics Data System (ADS)

    Werisch, S.; Lennartz, F.

    2014-12-01

    Inverse modeling has become a common approach to infer the parameters of the water retention and hydraulic conductivity functions from observations of the vadose zone state variables during dynamic experiments under varying boundary conditions. This study focuses on the estimation and investigation of the feasibility of effective soil hydraulic properties to describe the soil water flow in an undisturbed 1m³ lysimeter. The lysimeter is equipped with 6 one-dimensional observation arrays consisting of 4 tensiometers and 4 water content probes each, leading to 6 replicated one-dimensional observations which establish the calibration data base. Methods of global sensitivity analysis and multiobjective calibration strategies have been applied to examine the information content about the soil hydraulic parameters of the Mualem-van Genuchten (MvG) model contained in the individual data sets, to assess the tradeoffs between the different calibration data sets and to infer effective soil hydraulic properties for each of the arrays. The results show that (1) information about the MvG model parameters decreases with increasing depth, due to effects of overlapping soil layers and reduced soil water dynamics, (2) parameter uncertainty is affected by correlation between the individual parameters. Despite these difficulties, (3) effective one-dimensional parameter sets, which produce satisfying fits and have acceptable trade-offs, can be identified for all arrays, but (4) the array specific parameter sets vary significantly and cannot be transferred to simulate the water flow in other arrays, and (5) none of the parameter sets is suitable to simulate the integral water flow within the lysimeter. The results of the study challenge the feasibility of the inversely estimated soil hydraulic properties from multiple point measurements of the soil hydraulic state variables. Relying only on point measurements of the state variables, which is the usual case, inverse modeling can lead to

  19. Processes, mechanisms, parameters, and modeling approaches for partially saturated flow in soil and rock media; Yucca Mountain Site Characterization Project

    SciTech Connect

    Wang, J.S.Y.; Narasimhan, T.N.

    1993-06-01

    This report discusses conceptual models and mathematical equations, analyzes distributions and correlations among hydrological parameters of soils and tuff, introduces new path integration approaches, and outlines scaling procedures to model potential-driven fluid flow in heterogeneous media. To properly model the transition from fracture-dominated flow under saturated conditions to matrix-dominated flow under partially saturated conditions, characteristic curves and permeability functions for fractures and matrix need to be improved and validated. Couplings from two-phase flow, heat transfer, solute transport, and rock deformation to liquid flow are also important. For stochastic modeling of alternating units of welded and nonwelded tuff or formations bounded by fault zones, correlations and constraints on average values of saturated permeability and air entry scaling factor between different units need to be imposed to avoid unlikely combinations of parameters and predictions. Large-scale simulations require efficient and verifiable numerical algorithms. New path integration approaches based on postulates of minimum work and mass conservation to solve flow geometry and potential distribution simultaneously are introduced. This verifiable integral approach, together with fractal scaling procedures to generate statistical realizations with parameter distribution, correlation, and scaling taken into account, can be used to quantify uncertainties and generate the cumulative distribution function for groundwater travel times.

  20. Physicochemical Analysis of Ichamati River and Estimation of Soil Parameters using Geospatial Technology

    NASA Astrophysics Data System (ADS)

    Mondal, Ismail; Bandyopadhyay, Jatisankar

    2016-10-01

    Ichamati is a meandering tidal river of West Bengal. While meandering, the river forms of sharp loops and horse-shoes. During the formation of those horse-shoes severe damage is caused to the valuable lands and villages located on its concave banks. It appears that the formation of horse-shoes along the course is a characteristic of the river itself. It has, therefore, been proposed to study its characteristics by model experiments and to devise adequate means of protection which will successfully combat the river against washing away the costly lands and villages. In this connection, it has been felt necessary to make borings at the most affected reaches of the river in order to find out the nature of the soils underlying the existing bank. In September 2013, heavy rainfall occurred in earlier days of second sampling and the place was inundated by local runoff. Water coming down from locality reduced the total soluble salt and salinity value to a great extent. But after recession of the monsoon the values of total soluble salt salinity gradually increased and in April 2014 the values of total soluble salts were well over 1000 ppm, i.e. the water was `brackish' in salinity term. However, the suspended load values were well low to medium in all the cases. So the rapid deposition or silting is not likely to be correlated with the salinity increase or similar chemical reason. Siltation may rather be attributed to physical phenomena.

  1. Geothermal alteration of sediments in the Salton Sea scientific drill hole: Petrophysical properties and mass changes during alteration: Final report

    SciTech Connect

    McDowell, S.D.

    1987-12-11

    This report has been divided into two sections. The first deals with the results of the petrophysical measurements, and the second concentrates on the distribution of alteration minerals and textures, and on a series of calculations of geochemical changes that occurred during alteration. 32 refs., 23 figs., 10 tabs.

  2. Estimation of Field-scale Aquifer Hydraulic and Sorption Parameters Based on Borehole Spectral Gamma Methods

    NASA Astrophysics Data System (ADS)

    Ward, A. L.; Draper, K.; Hasan, N.

    2010-12-01

    Knowledge of spatially variable aquifer hydraulic and sorption parameters is a pre-requisite for an improved understanding of the transport and spreading of sorbing solutes and for the development of effective strategies for remediation. Local-scale estimates of these parameters are often derived from core measurements but are typically not representative of field values. Fields-scale estimates are typically derived from pump and tracer tests but often lack the spatial resolution necessary to deconvolve the effects of fine-scale heterogeneities. Geophysical methods have the potential to bridge this gap both in terms of coverage and resolution, provided meaningful petrophysical relationships can be developed. The objective of this study was to develop a petrophysical relationship between soil textural attributes and the gamma-energy response of natural sediments. Measurements from Hanford’s 300 Area show the best model to be a linear relationship between 232Th concentration and clay content (R2 = 94%). This relationship was used to generate a 3-D distribution of clay mass fraction based on borehole spectral gamma logs. The distribution of clay was then used to predict distributions of permeability, porosity, bubbling pressure, and the pore-size distribution index, all of which are required for predicting variably saturated flow, as well as the specific surface area and cation exchange capacity needed for reactive transport predictions. With this approach, it is possible to obtain reliable estimates of hydraulic properties in zones that could not be characterized by field or laboratory measurements. The spatial distribution of flow properties is consistent with lithologic transitions inferred from geologist’s logs. A preferential flow path, identified from solute and heat tracer experiments and attributed to an erosional incision in the low-permeability Ringold Formation, is also evident. The resulting distributions can be used as a starting model for the

  3. Impact of mechanical mowing and chemical treatment on phytosociological, pedochemical and biological parameters in roadside soils and vegetation.

    PubMed

    Pellegrini, Elisa; Falcone, Lino; Loppi, Stefano; Lorenzini, Giacomo; Nali, Cristina

    2016-03-01

    Many chemical and non-chemical strategies have been applied to control weeds in agricultural and industrial areas. Knowledge regarding the effects of these methods on roadside vegetation is still poor. A 2-year field experiment was performed along a road located near Livorno (Tuscany, central Italy). Eight plots/strips were identified, of which four were subjected to periodical mechanical mowing and the remaining four were treated with a chemical herbicide based on glyphosate (the producer's recommended rates were used for the selective control of broad-leaved weeds). Our results clearly showed that roadside soil and vegetation are a significant reservoir of anthropogenic activities which have a strong negative effect on several phytosociological, pedochemical and biological parameters. Compared with conventional mechanical mowing, chemical treatment induced (i) a significant increase in organic matter in the upper plot layers (+18%), and (ii) a marked reduction in weed height throughout the entire period of the experiment. Irrespectively of the kind of treatment, no significance differences were detected in terms of (i) biological quality of soil (the abundance and diversity of arthropod communities did not change), and (ii) plant elemental content (bulk concentrations of analysed trace elements had a good fit within ranges of occurrence in the "reference plant"). The glyphosate partially controlled broad-leaved weeds and this moderate efficacy is dependent upon the season/time of application. In conclusion, the rational and sustainable use of chemical herbicides may be a useful tool for the management of roadside vegetation.

  4. Impact of mechanical mowing and chemical treatment on phytosociological, pedochemical and biological parameters in roadside soils and vegetation.

    PubMed

    Pellegrini, Elisa; Falcone, Lino; Loppi, Stefano; Lorenzini, Giacomo; Nali, Cristina

    2016-03-01

    Many chemical and non-chemical strategies have been applied to control weeds in agricultural and industrial areas. Knowledge regarding the effects of these methods on roadside vegetation is still poor. A 2-year field experiment was performed along a road located near Livorno (Tuscany, central Italy). Eight plots/strips were identified, of which four were subjected to periodical mechanical mowing and the remaining four were treated with a chemical herbicide based on glyphosate (the producer's recommended rates were used for the selective control of broad-leaved weeds). Our results clearly showed that roadside soil and vegetation are a significant reservoir of anthropogenic activities which have a strong negative effect on several phytosociological, pedochemical and biological parameters. Compared with conventional mechanical mowing, chemical treatment induced (i) a significant increase in organic matter in the upper plot layers (+18%), and (ii) a marked reduction in weed height throughout the entire period of the experiment. Irrespectively of the kind of treatment, no significance differences were detected in terms of (i) biological quality of soil (the abundance and diversity of arthropod communities did not change), and (ii) plant elemental content (bulk concentrations of analysed trace elements had a good fit within ranges of occurrence in the "reference plant"). The glyphosate partially controlled broad-leaved weeds and this moderate efficacy is dependent upon the season/time of application. In conclusion, the rational and sustainable use of chemical herbicides may be a useful tool for the management of roadside vegetation. PMID:26573685

  5. Determining the influence of the physicochemical parameters of urban soils on As availability using chemometric methods: A preliminary study.

    PubMed

    Waterlot, Christophe; Pelfrêne, Aurélie; Douay, Francis

    2016-09-01

    An initial exploration was conducted using mathematical and statistical methods to obtain relevant information about the determination of the physicochemical parameters capable of controlling As uptake by ryegrass grown on contaminated topsoils. Concentrations of As in the soils were from 10 to 47mg/kg, mainly in the As(V) form (57%-73%). Concentrations of As in water extracts were very low (61-700μg/kg). It was suggested that As(III) was mainly in the uncharged species and As(V) in the charged species. Chemometric methods revealed that the values of the ratio As(III)/As(V) depended on the assimilated-phosphorus, the pseudo-total and water-extractable Fe contents and the soil pH. Arsenic concentrations measured in ryegrass shoots ranged from 119 to 1602μg/kg. Positive linear correlations were obtained between As in ryegrass shoots and water extractable-As. The transfer coefficient of As correlated well with the ratio assimilated-phosphorus/Fe-oxides. As(III) uptake by the shoot of ryegrass was controlled by the organic matter and Fe-oxide contents. PMID:27593285

  6. Site-specific analysis of radiological and physical parameters for cobbly soils at the Gunnison, Colorado, processing site. Revision 1

    SciTech Connect

    Not Available

    1994-01-01

    The remedial action at the Gunnison, Colorado, processing site is being performed under the Uranium Mill Tailings Radiation Control Act (UMTRCA) of 1978. Under UMTRCA, the US Environmental Protection Agency (EPA) is charged with the responsibility of developing appropriate and applicable standards for the cleanup of radiologically contaminated land and buildings at 24 designated sites, including the Gunnison, Colorado, inactive processing site. Section 108 of Public Law 95-604 states that the US Department of Energy (DOE) shall ``select and perform remedial actions at the designated processing sites and disposal sites in accordance with the general standards`` prescribed by the EPA. Regulations governing the required remedial action at inactive uranium processing sites were promulgated by the EPA in 1983 and are contained in 40 CFR Part 192 (1993), Health and Environmental Protection Standards for Uranium and Thorium Mill Tailings. This document describes the radiological and physical parameters for the remedial action of the soil.

  7. Influence of physicochemical parameters of neem (Azadirachta indica A Juss) oils on nitrification inhibition in soil.

    PubMed

    Kumar, Rajesh; Devakumar, C; Sharma, Vandana; Kakkar, Garima; Kumar, Dinesh; Panneerselvam, P

    2007-02-21

    The technology for the production of neem oil coated urea (NOCU) developed by the Indian Agricultural Research Institute is in the pipeline for adaption by several Indian fertilizer industries. Use of nitrification inhibitors is one of the methods of improving the nitrogen use efficiency (NUE) of nitrogenous fertilizers in agriculture. However, standard specifications for the neem oil as a raw material of NOCU are desired. Accordingly, the present study was undertaken to evaluate 25 samples of neem oils comprising 11 samples of expeller grade (EG) oils, 8 samples of cold-pressed (CP) oils, 3 samples of solvent-extracted oils, and 2 commercial formulations. NOCU was prepared using these oils (5000 ppm of urea-N). The soils fertilized with NOCUs (200 ppm of urea-N) were incubated at 27 degrees C and 50% water-holding capacity for a period of 15 days. Nitrapyrin (0.5% of N) coated urea served as the reference and prilled urea as control. Samples were analyzed for NH4+-N, NO2--N, and NO3--N using standard methods. The percent nitrification inhibition (NI) was calculated, and the results revealed that all of the neem oils caused NI ranging from 4.0 to 30.9%. Two samples of EG oils and two commercial formulations were found to be the best, causing 27.0-30.9% NI. Iodine, acid, and saponification values and meliacin content of all of the oils were analyzed and correlated with NI. The results revealed the direct influence of meliacin content of the neem oils on NI, which, however, was found to be negatively correlated with saponification and iodine values. There is, therefore, a need to introduce new Bureau of Indian Standards (BIS) specifications for neem oils as raw materials of NOCU. PMID:17263551

  8. Influence of physicochemical parameters of neem (Azadirachta indica A Juss) oils on nitrification inhibition in soil.

    PubMed

    Kumar, Rajesh; Devakumar, C; Sharma, Vandana; Kakkar, Garima; Kumar, Dinesh; Panneerselvam, P

    2007-02-21

    The technology for the production of neem oil coated urea (NOCU) developed by the Indian Agricultural Research Institute is in the pipeline for adaption by several Indian fertilizer industries. Use of nitrification inhibitors is one of the methods of improving the nitrogen use efficiency (NUE) of nitrogenous fertilizers in agriculture. However, standard specifications for the neem oil as a raw material of NOCU are desired. Accordingly, the present study was undertaken to evaluate 25 samples of neem oils comprising 11 samples of expeller grade (EG) oils, 8 samples of cold-pressed (CP) oils, 3 samples of solvent-extracted oils, and 2 commercial formulations. NOCU was prepared using these oils (5000 ppm of urea-N). The soils fertilized with NOCUs (200 ppm of urea-N) were incubated at 27 degrees C and 50% water-holding capacity for a period of 15 days. Nitrapyrin (0.5% of N) coated urea served as the reference and prilled urea as control. Samples were analyzed for NH4+-N, NO2--N, and NO3--N using standard methods. The percent nitrification inhibition (NI) was calculated, and the results revealed that all of the neem oils caused NI ranging from 4.0 to 30.9%. Two samples of EG oils and two commercial formulations were found to be the best, causing 27.0-30.9% NI. Iodine, acid, and saponification values and meliacin content of all of the oils were analyzed and correlated with NI. The results revealed the direct influence of meliacin content of the neem oils on NI, which, however, was found to be negatively correlated with saponification and iodine values. There is, therefore, a need to introduce new Bureau of Indian Standards (BIS) specifications for neem oils as raw materials of NOCU.

  9. Petrophysical and petrographic evaluation of Sidri Member of Belayim Formation, Badri field, Gulf of Suez, Egypt

    NASA Astrophysics Data System (ADS)

    Abudeif, A. M.; Attia, M. M.; Radwan, A. E.

    2016-03-01

    Presence of sandstone streaks in Sidri Member within Belayim Formation that lies between two productive zones; Kareem Formation and Hammam Faraun Member, was the main reason to perform this study. It may represent a good hydrocarbon reservoir and will be added to the Egyptian oil production in some wells of Badri field. This Member has high resistivity signature on Electric-logs responses which attracted the attention to investigate its occurrence in the field, to delineate its distribution all-over the area, to evaluate the petrographic and petrophysical characteristics and to evaluate its productivity. Petrographic and petrophysical analyses of these sand zones were undertaken using thin section samples. The electric logs and subsurface geologic data was used to evaluate the main reservoir characteristics of the Sidri sandstone such as lithology, cementation, shale volume, porosity (Φ), effective porosity (Φ eff), estimated permeability (K), fluid saturation, fluid type and Net pay thickness. This study revealed that, Sidri sandstone facies was classified into two mainly sandy facies; blocky sandy facies which located at the northern part of the field and streaky sandy facies at the southern area of the field. These two facies are separated by shaley facies. Some wells were studied to represent the two sandy facies in Sidri Member and these sand intervals have not been tested yet. These sands consist of quartz grains with grey and pink feldspars as accessory minerals, with siliceous and calcareous cementation, with good porosity. Petrophysical evaluation of this sand unit indicated that it is hydrocarbon bearing formation in three wells and water bearing one in other wells. Electrical logs analysis (Resistivity, Density-Neutron, Sonic and Gamma-Ray) revealed that The volume of shale in this sandstone, the effective porosity, the water saturation, the estimated permeability, the hydrocarbon saturation, and the net-pay thickness are varying from 9 to 13%, 19

  10. [Diurnal variation of gas exchange and chlorophyll fluorescence parameters of cotton functional leaves under effects of soil salinity].

    PubMed

    Zhang, Guo-wei; Zhang, Lei; Tang, Ming-xing; Zhou, Ling-ling; Chen, Bing-lin; Zhou, Zhi-guo

    2011-07-01

    A two-year (2007-2008) pot experiment with cotton varieties Sumian 12 (salinity-sensitive) and Zhongmiansuo 44 (salinity-tolerance) was conducted at the Pailou experimental station of Nanjing Agricultural University to study the diurnal variation of the gas exchange and chlorophyll fluorescence parameters of cotton functional leaves under five levels (0, 0.35%, 0.60% , 0.85%, and 1.00%) of soil salinity. With the increase of soil salinity, the concentrations of Na+, Cl-, and Mg2+ in functional leaves increased, whereas the concentrations of K+ and Ca2+ decreased. The salinity level <0. 35% had little effects on the gas exchange and chlorophyll fluorescence parameters, but that >0.35% depressed the net photosynthetic rate (Pn) dramatically. At the salinity level >0.35%, the sensitivity of functional leaves to daytime photon flux density (PFD) and air temperature (Ta) enhanced, which in turn resulted in more severe photo- and temperature inhibition, and changed the diurnal variation patterns of Pn and stomatal conductance (Gs) from a one-peak curve to a constantly decreasing one. Along with the variations of daytime PED and Ta, the diurnal variation patterns of the maximum photochemical efficiency (F(v)/F(m)), quantum yield of electron transport (phi(PS II), and photochemical quenching coefficient (q(P)) of functional leaves presented a V-shaped curve, with the minimum value appeared at 12:00-13:00, while the non-photochemical quenching coefficient (q(N)) showed a single-peak curve. Soil salinity decreased the F(v)/F(m), phi(PS II), and q(P) significantly, but increased the q(N) and enlarged its change trend. The comparatively low concentrations of Na+ and Cl- and the relatively high concentrations of K+ and Ca2+ in salt-tolerant Zhongmiansuo 44 functional leaves benefited the relative stability of PS II, and the maintenance of a relatively high thermal dissipation capacity could be one of the reasons for a high level of Pn at high salinity level.

  11. Petrofacies Analysis - A Petrophysical Tool for Geologic/Engineering Reservoir Characterization

    USGS Publications Warehouse

    Watney, W.L.; Guy, W.J.; Doveton, J.H.; Bhattacharya, S.; Gerlach, P.M.; Bohling, G.C.; Carr, T.R.

    1998-01-01

    Petrofacies analysis is defined as the characterization and classification of pore types and fluid saturations as revealed by petrophysical measurements of a reservoir. The word "petrofacies" makes an explicit link between petroleum engineers' concerns with pore characteristics as arbiters of production performance and the facies paradigm of geologists as a methodology for genetic understanding and prediction. In petrofacies analysis, the porosity and resistivity axes of the classical Pickett plot are used to map water saturation, bulk volume water, and estimated permeability, as well as capillary pressure information where it is available. When data points are connected in order of depth within a reservoir, the characteristic patterns reflect reservoir rock character and its interplay with the hydrocarbon column. A third variable can be presented at each point on the crossplot by assigning a color scale that is based on other well logs, often gamma ray or photoelectric effect, or other derived variables. Contrasts between reservoir pore types and fluid saturations are reflected in changing patterns on the crossplot and can help discriminate and characterize reservoir heterogeneity. Many hundreds of analyses of well logs facilitated by spreadsheet and object-oriented programming have provided the means to distinguish patterns typical of certain complex pore types (size and connectedness) for sandstones and carbonate reservoirs, occurrences of irreducible water saturation, and presence of transition zones. The result has been an improved means to evaluate potential production, such as bypassed pay behind pipe and in old exploration wells, or to assess zonation and continuity of the reservoir. Petrofacies analysis in this study was applied to distinguishing flow units and including discriminating pore type as an assessment of reservoir conformance and continuity. The analysis is facilitated through the use of colorimage cross sections depicting depositional sequences

  12. Computational Challenges in the Analysis of Petrophysics Using Microtomography and Upscaling

    NASA Astrophysics Data System (ADS)

    Liu, J.; Pereira, G.; Freij-Ayoub, R.; Regenauer-Lieb, K.

    2014-12-01

    Microtomography provides detailed 3D internal structures of rocks in micro- to tens of nano-meter resolution and is quickly turning into a new technology for studying petrophysical properties of materials. An important step is the upscaling of these properties as micron or sub-micron resolution can only be done on the sample-scale of millimeters or even less than a millimeter. We present here a recently developed computational workflow for the analysis of microstructures including the upscaling of material properties. Computations of properties are first performed using conventional material science simulations at micro to nano-scale. The subsequent upscaling of these properties is done by a novel renormalization procedure based on percolation theory. We have tested the workflow using different rock samples, biological and food science materials. We have also applied the technique on high-resolution time-lapse synchrotron CT scans. In this contribution we focus on the computational challenges that arise from the big data problem of analyzing petrophysical properties and its subsequent upscaling. We discuss the following challenges: 1) Characterization of microtomography for extremely large data sets - our current capability. 2) Computational fluid dynamics simulations at pore-scale for permeability estimation - methods, computing cost and accuracy. 3) Solid mechanical computations at pore-scale for estimating elasto-plastic properties - computational stability, cost, and efficiency. 4) Extracting critical exponents from derivative models for scaling laws - models, finite element meshing, and accuracy. Significant progress in each of these challenges is necessary to transform microtomography from the current research problem into a robust computational big data tool for multi-scale scientific and engineering problems.

  13. The impact of different soil parameters on the community structure of dominant bacteria from nine different soils located on Livingston Island, South Shetland Archipelago, Antarctica.

    PubMed

    Ganzert, Lars; Lipski, André; Hubberten, Hans-Wolfgang; Wagner, Dirk

    2011-06-01

    Microorganisms inhabit very different soil habitats in the ice-free areas of Antarctica, playing a major role in nutrient cycling in cold environments. We studied the soil characteristics and the dominant bacterial composition from nine different soil profiles located on Livingston Island (maritime Antarctica). The total carbon (TC) and total nitrogen (TN) values were high for the vegetated soils, decreasing with depth, whereas the values for the mineral soils were generally low. Soil pH was more acidic for moss-covered soils and neutral to alkaline for mineral soils. Numbers of culturable heterotrophic bacteria were higher at vegetated sites, but significant numbers were also detectable in carbon-depleted soils. Patterns of denaturing gradient gel electrophoresis (DGGE) revealed a highly heterogeneous picture throughout the soil profiles. Subsequent sequencing of DGGE bands revealed in total 252 sequences that could be assigned to 114 operational taxonomic units, showing the dominance of members of the Bacteroidetes and Acidobacteria. The results of phospholipid fatty acid analysis showed a lack of unsaturated fatty acids for most of the samples. Samples with a prevalence of unsaturated over saturated fatty acids were restricted to several surface samples. Statistical analysis showed that the dominant soil bacterial community composition is most affected by TC and TN contents and soil physical factors such as grain size and moisture, but not pH.

  14. Drivers of spatial patterns of physiological and soil parameters at micro- and field scale in a Hungarian sandy grassland

    NASA Astrophysics Data System (ADS)

    Fóti, Szilvia; Balogh, János; Papp, Marianna; Zimmermann, Zita; Szabó, Gábor; Herbst, Michael; Biró, Marianna; Bartha, Sándor; Horváth, László; Nagy, Zoltán

    2014-05-01

    Plant physiological and soil parameters were sampled at two spatial scales on mowed and grazed sites of a semiarid sandy grassland in Hungary. Samples from 80×60 m grids of 10 m resolution with additional random points represented the field scale (78 positions), while measurements along every 20 cm of circular transects of 15 m length represented the micro-scale (75 positions). 22 transects were measured between 2004 and 2012 at micro-scale, and 6 grids in 2012-2013 at field scale. At the micro-scale, there was no apparent elevation (E) difference, nor any other spatial non-stationarity. Contrarily, apparent micro-relief and above-ground biomass (AGB) differences emerged at the field scale. Sampled variables were soil water content (SWC), soil temperature (Ts) and soil CO2 efflux (Rs) at the micro-scale, and these were complemented with E and AGB at the field scale. N2O was sampled spatially once at both sites, in autumn 2012. Spatial patterns of the variables were investigated by variograms and cross-variograms. Autocorrelation lengths of the measured variables varied between 0-3.5 m at the micro scale. SWC was the main determinant of both the spatial variability and patch size of Rs, because dry conditions increased variability of the measured flux together with the characteristic patch size of Rs. Furthermore, optimal sample size and adequate sampling scheme could be estimated on the basis of actual SWC. Ts proved to negatively co-vary with SWC, which resulted in negative spatial dependency between Ts and Rs, contrary to the expectations. Effect of SWC was of two different sorts in this respect, in dry patches it directly limited Rs, while in wet patches it had a cooling effect, leading to the confounding response of Rs to Ts. These observations pointed to the relevance of SWC in model approaches. At field scale, deviations in E and AGB produced a different setting for spatial correlation. In case of the mowed site, we found a coherent patch structure of about

  15. Use of a flux-based field capacity criterion to identify effective hydraulic parameters of layered soil profiles subjected to synthetic drainage experiments

    NASA Astrophysics Data System (ADS)

    Nasta, Paolo; Romano, Nunzio

    2016-01-01

    This study explores the feasibility of identifying the effective soil hydraulic parameterization of a layered soil profile by using a conventional unsteady drainage experiment leading to field capacity. The flux-based field capacity criterion is attained by subjecting the soil profile to a synthetic drainage process implemented numerically in the Soil-Water-Atmosphere-Plant (SWAP) model. The effective hydraulic parameterization is associated to either aggregated or equivalent parameters, the former being determined by the geometrical scaling theory while the latter is obtained through the inverse modeling approach. Outcomes from both these methods depend on information that is sometimes difficult to retrieve at local scale and rather challenging or virtually impossible at larger scales. The only knowledge of topsoil hydraulic properties, for example, as retrieved by a near-surface field campaign or a data assimilation technique, is often exploited as a proxy to determine effective soil hydraulic parameterization at the largest spatial scales. Comparisons of the effective soil hydraulic characterization provided by these three methods are conducted by discussing the implications for their use and accounting for the trade-offs between required input information and model output reliability. To better highlight the epistemic errors associated to the different effective soil hydraulic properties and to provide some more practical guidance, the layered soil profiles are then grouped by using the FAO textural classes. For the moderately heterogeneous soil profiles available, all three approaches guarantee a general good predictability of the actual field capacity values and provide adequate identification of the effective hydraulic parameters. Conversely, worse performances are encountered for the highly variable vertical heterogeneity, especially when resorting to the "topsoil-only" information. In general, the best performances are guaranteed by the equivalent

  16. Use of morphometric soil aggregates parameters to evaluate the reclamation process in mined areas located at amazon forest - Brazil

    NASA Astrophysics Data System (ADS)

    Ribeiro, A. I.; Fengler, F. H.; Longo, R. M.; Mello, G. F.; Damame, D. B.; Crowley, D. E.

    2015-12-01

    Brazil has a high mineral potential that have been explored over the years. A large fraction of these mineral resources are located in Amazon region, which is known for its large biodiversity and world climate importance. As the policies that control the Amazon preservation are relatively new, several mining activities have been exploring the Amazon territory, promoting a large process of degradation. Once the mining activities have a high potential of environmental changes the government created polices to restrain the mining in Amazon forests and obligate mining companies to reclaim theirs minded areas. However, the measurement of reclamation development still is a challenging task for the Professionals involved. The volume and complexity of the variables, allied to the difficulty in identifying the reclamation of ecosystem functionalities are still lack to ensure the reclamation success. In this sense this work aims to investigate the representativeness of morphometric soil aggregates parameters in the understanding of reclamation development. The study area is located in the National Forest of Jamari, State of Rondônia. In the past mining companies explored the region producing eight closed mines that are now in reclamation process. The soil aggregates morphometric measurements: geometric mean diameter (GMD), aggregate circularity index, and aggregate roundness, were choose based in its obtaining facility, and their association to biological activity. To achieve the proposed objective the aggregates of eight sites in reclamation, from different closed mines, where chosen and compared to Amazon forest and open mine soil aggregates. The results were analyzed to one way ANOVA to identifying differences between areas in reclamation, natural ecosystem, and open mine. It was obtained differences for GMD and circularity index. However, only the circularity index allowed to identifying differences between the reclamation sites. The results allowed concluding: (1

  17. Detailed petrophysical and geophysical characterization of core samples from the potential caprock-reservoir system in the Sulcis Coal Basin (South-Western Sardinia - Italy).

    NASA Astrophysics Data System (ADS)

    Fais, Silvana; Ligas, Paola; Cuccuru, Francesco; Maggio, Enrico; Plaisant, Alberto; Pettinau, Alberto

    2015-04-01

    The evaluation of the CO2 geologic storage site requires a robust experimental database especially with respect to spatial petrophysical heterogeneities. The integrated analysis of minero-petrographical, physical and geophysical parameters (e.g. longitudinal and transversal propagation velocity, VpVs ratio, dynamic elastic moduli, etc.) of the rocks that make up a caprock-reservoir system can substantially reduce the geologic uncertainity in the storage site characterization and in the geological and numerical modelling for the evaluation of the CO2 storage capacity. In this study the Middle Eocene - Lower Oligocene Cixerri Formation made up of siliciclastic rocks and the Upper Thanetian - Lower Ypresian Miliolitico Carbonate Complex in the Sulcis coal basin (South-Western Sardinia - Italy) have been identified respectively as potential caprock and reservoir for the CO2 storage. The petrographical, physical and geophysical parameters of the above mentioned geological Formations (Cixerri and Milolitico) were investigated to improve the geological model aimed at verifying the geological CO2 storage capacity within the carbonate reservoir rocks, in order to guarantee an efficient use of the reservoir, and to improve the numerical simulation of CO2 behaviour in the short, medium and long term after its injection in single or multiple wells. . The petrographical characteristics of the caprock-reservoir rocks were determined by optical and SEM analyses of core samples representing the different facies of the Cixerri Formation and of the Miliolitico Carbonate Complex, provided by Carbosulcis S.p.A.. Porosity analysis was completed by mercury porosimeter determinations which also provided quantitative information on the permeability of the study rocks and on the tortuosity of their pore system. Further physical properties, such as dry and saturated density and porosity, and water absorption were determined on the cylindrical core samples of intact rocks (ISRM, 1979) from

  18. Sustainability of an in situ aided phytostabilisation on highly contaminated soils using fly ashes: Effects on the vertical distribution of physicochemical parameters and trace elements.

    PubMed

    Bidar, Géraldine; Waterlot, Christophe; Verdin, Anthony; Proix, Nicolas; Courcot, Dominique; Détriché, Sébastien; Fourrier, Hervé; Richard, Antoine; Douay, Francis

    2016-04-15

    Aided phytostabilisation using trees and fly ashes is a promising technique which has shown its effectiveness in the management of highly metal-contaminated soils. However, this success is generally established based on topsoil physicochemical analysis and short-term experiments. This paper focuses on the long-term effects of the afforestation and two fly ashes (silico-aluminous and sulfo-calcic called FA1 and FA2, respectively) by assessing the integrity of fly ashes 10 years after their incorporation into the soil as well as the vertical distribution of the physicochemical parameters and trace elements (TEs) in the amended soils (F1 and F2) in comparison with a non-amended soil (R). Ten years after the soil treatment, the particle size distribution analysis between fly ashes and their corresponding masses (fly ash + soil particles) showed a loss or an agglomeration of finer particles. This evolution matches with the appearance of gypsum (CaSO4 2H2O) in FA2m instead of anhydrite (CaSO4), which is the major compound of FA2. This finding corresponds well with the dissolution and the lixiviation of Ca, S and P included in FA2 along the F2 soil profile, generating an accumulation of these elements at 30 cm depth. However, no variation of TE contamination was found between 0 and 25 cm depth in F2 soil except for Cd. Conversely, Cd, Pb, Zn and Hg enrichment was observed at 25 cm depth in the F1 soil, whereas no enrichment was observed for As. The fly ashes studied, and notably FA2, were able to reduce Cd, Pb and Zn availability in soil and this capacity persists over the time despite their structural and chemical changes. PMID:26897554

  19. Effect of seed pre-soaking with 24-epibrassinolide on growth and photosynthetic parameters of Brassica juncea L. in imidacloprid soil.

    PubMed

    Sharma, Anket; Kumar, Vinod; Singh, Ravinder; Thukral, Ashwani Kumar; Bhardwaj, Renu

    2016-11-01

    Pesticides are widely used to protect crop plants from various insect pests. However, application of pesticides causes phytotoxicity to plants which results in their impaired growth and development. Brassinosteroids are well known to protect plants under abiotic stress conditions. The purpose of the present study was to access the ameliorative role of 24-epibrassinolide (EBR) in Brassica juncea L. under imidacloprid (IMI) toxicity. B. juncea plants were raised from seeds soaked in 0.1, 1 and 100nM of EBR, and grown in soils amended with 250, 300 and 350mgkg(-1) IMI pesticide, and observed for growth, pigments and photosynthetic parameters after 30, 60 and 90 days of seed sowing. The plants grown in soil treated with IMI exhibited a significant reduction in shoot length, number of leaves, chlorophyll contents and photosynthetic parameters like photosynthetic rate, stomatal conductance, inter-cellular CO2 and transpiration rate, when compared with their respective controls. However, pigments which act as antioxidants such as carotenoids, anthocyanins and xanthophylls were increased with IMI stress. Pre-sowing seed treatment with EBR decreased the toxic effects of IMI and increased the growth, pigment biosynthesis and photosynthetic parameters of the plants grown in IMI amended soil. Maximum increase in all the growth and photosynthetic parameters was noticed in plants raised from seeds treated with 100nM EBR and grown in IMI amended soil. PMID:27454204

  20. Effect of seed pre-soaking with 24-epibrassinolide on growth and photosynthetic parameters of Brassica juncea L. in imidacloprid soil.

    PubMed

    Sharma, Anket; Kumar, Vinod; Singh, Ravinder; Thukral, Ashwani Kumar; Bhardwaj, Renu

    2016-11-01

    Pesticides are widely used to protect crop plants from various insect pests. However, application of pesticides causes phytotoxicity to plants which results in their impaired growth and development. Brassinosteroids are well known to protect plants under abiotic stress conditions. The purpose of the present study was to access the ameliorative role of 24-epibrassinolide (EBR) in Brassica juncea L. under imidacloprid (IMI) toxicity. B. juncea plants were raised from seeds soaked in 0.1, 1 and 100nM of EBR, and grown in soils amended with 250, 300 and 350mgkg(-1) IMI pesticide, and observed for growth, pigments and photosynthetic parameters after 30, 60 and 90 days of seed sowing. The plants grown in soil treated with IMI exhibited a significant reduction in shoot length, number of leaves, chlorophyll contents and photosynthetic parameters like photosynthetic rate, stomatal conductance, inter-cellular CO2 and transpiration rate, when compared with their respective controls. However, pigments which act as antioxidants such as carotenoids, anthocyanins and xanthophylls were increased with IMI stress. Pre-sowing seed treatment with EBR decreased the toxic effects of IMI and increased the growth, pigment biosynthesis and photosynthetic parameters of the plants grown in IMI amended soil. Maximum increase in all the growth and photosynthetic parameters was noticed in plants raised from seeds treated with 100nM EBR and grown in IMI amended soil.

  1. Temporal variability in bioassays of ammonia exchange potential in relation to plant and soil nitrogen parameters in intensively managed grassland

    NASA Astrophysics Data System (ADS)

    Mattsson, M.; Herrmann, B.; David, M.; Loubet, B.; Riedo, M.; Theobald, M. R.; Sutton, M. A.; Bruhn, D.; Neftel, A.; Schjoerring, J. K.

    2008-07-01

    The exchange of ammonia between crop canopies and the atmosphere depends on a range of plant parameters and climatic conditions but little is known about effects of management factors. We have here investigated the ammonia exchange potential of a grass sward dominated by Lolium perenne in response to cutting and fertilization. Tall grass showed a low potential for NH3 emission before cutting. During re-growth after cutting, leaf tissue concentrations of NO3-, NH4+, soluble N and total N increased along with apoplastic NH4+ concentrations. In contrast, apoplastic pH decreased resulting in largely unaltered NH3 emission potential. A high potential for NH3 emission was shown by the plant litter. Fertilization with 100 kg N ha-1 one week after cutting caused the apoplastic NH4+ concentration of the newly emerging leaves to increase dramatically. The apoplastic NH4+ concentration peaked the day after the fertiliser was applied and thereafter decreased over the following 10 days until reaching the same level as before fertilisation. A positive correlation was found between NH4+ concentrations in leaf apoplast, bulk tissue and litter throughout the experimental period. Leaf soluble N was negatively correlated with apoplastic NH4+ concentration whereas total N was weakly correlated with NH4+ concentrations in leaf tissue and soil.

  2. Petrophysical Analysis and Geographic Information System for San Juan Basin Tight Gas Reservoirs

    SciTech Connect

    Martha Cather; Robert Lee; Robert Balch; Tom Engler; Roger Ruan; Shaojie Ma

    2008-10-01

    The primary goal of this project is to increase the availability and ease of access to critical data on the Mesaverde and Dakota tight gas reservoirs of the San Juan Basin. Secondary goals include tuning well log interpretations through integration of core, water chemistry and production analysis data to help identify bypassed pay zones; increased knowledge of permeability ratios and how they affect well drainage and thus infill drilling plans; improved time-depth correlations through regional mapping of sonic logs; and improved understanding of the variability of formation waters within the basin through spatial analysis of water chemistry data. The project will collect, integrate, and analyze a variety of petrophysical and well data concerning the Mesaverde and Dakota reservoirs of the San Juan Basin, with particular emphasis on data available in the areas defined as tight gas areas for purpose of FERC. A relational, geo-referenced database (a geographic information system, or GIS) will be created to archive this data. The information will be analyzed using neural networks, kriging, and other statistical interpolation/extrapolation techniques to fine-tune regional well log interpretations, improve pay zone recognition from old logs or cased-hole logs, determine permeability ratios, and also to analyze water chemistries and compatibilities within the study area. This single-phase project will be accomplished through four major tasks: Data Collection, Data Integration, Data Analysis, and User Interface Design. Data will be extracted from existing databases as well as paper records, then cleaned and integrated into a single GIS database. Once the data warehouse is built, several methods of data analysis will be used both to improve pay zone recognition in single wells, and to extrapolate a variety of petrophysical properties on a regional basis. A user interface will provide tools to make the data and results of the study accessible and useful. The final deliverable

  3. Petrophysical and Mechanical Properties of Fractured Aquifers in the Northern Newark Basin: Implications for Carbon Sequestration

    NASA Astrophysics Data System (ADS)

    Zakharova, N. V.; Goldberg, D.; Collins, D.; Olsen, P. E.

    2012-12-01

    One of the key factors in predicting the performance of low-permeability fractured reservoirs is a detailed understanding of the in-situ state of stress and the distribution and orientation of natural fractures and faults. In this study we analyze borehole geophysical data from a deep characterization well in the northern Newark Basin, a candidate CO2-storage site, and provide petrophysical and geomechanical characterization of fractured sedimentary and igneous formations. Previous studies in the northern Newark basin demonstrated no unique relationship between hydraulic conductivity and degree of fracturing, fracture apertures or orientation. Therefore, in the absence of hydraulic testing data predicting fracture behavior under CO2 injection condition presents a significant challenge for baseline formation characterization. Moreover, fluid injection in deep wells can cause reactivation of existing faults or new fracture initiation due to significant increase in the pore pressure. We analyze electrical resistivity images and full-wave sonic data to constrain the state of the current in-situ stress in the northern Newark basin, and to evaluate how the interaction between in-situ stress and the distribution and orientation of natural fractures influences their hydraulic properties. We then combine it with the full suite of wireline logs to describe petrophysical, hydraulic, and geomechanical properties of the fractured aquifers at the locality. The Sandia Technologies, LLC Tandem Lot #1 geologic characterization well (Rockland County, NY) is about 6,800 ft deep and transects Triassic terrestrial sediments and the Palisades diabase sill that are both characterized by abundant natural fractures. A suite of standard wireline logs, high-resolution electrical resistivity images and full-wave sonic data were collected in the borehole but no hydraulic data or in-situ stress estimates are available. Borehole breakouts are clearly observed in the resistivity images in

  4. Combined geophysical and petrophysical characterization to support a hydrogeological model of a coastal environment

    NASA Astrophysics Data System (ADS)

    Burschil, Thomas; Wiederhold, Helga; Scheer, Wolfgang; Kirsch, Reinhard; Krawczyk, Charlotte M.

    2014-05-01

    Global warming affects the water cycle by changing precipitation/evaporation and raising sea level. Especially groundwater systems in sensitive environments, such as coastal areas or barrier islands, have to be evaluated with respect to the potential reduction of water quality, e.g. salinization by saltwater intrusion (Hinsby et al., 2012). To assess these hazards using groundwater modeling we need a strong base of hydraulic and hydrogeological information. The use of integrated geophysical methods, in combination with a petrophysical characterization, provides a reliable architecture for groundwater modeling. Within the EU-project CLIWAT, we investigated the hydrogeological situation of the North Sea island of Föhr in Schleswig-Holstein (Germany). The island was mainly formed during glaciations in Pleistocene Series, especially Saalian and Weichselian Stages. These deposits remain as a Geest core in the southern central part, and house a freshwater lens that is used for the local water supply. To investigate the architecture of the fresh water lens, we carried out several surveys with airborne electromagnetic (AEM), seismic reflection, and borehole methods. To enhance the AEM resistivity model we inverted the data with a-priori constraints from seismic reflections (Burschil et al., 2012a). This constrained inversion leads to, among other things, a separation of two aquifers by resistivity data. Additionally, from borehole logs, vertical seismic profiles (VSP), and nearby AEM inversion point models we are able to petrophysically characterize different lithological categories regarding resistivity and seismic velocity. Subsurface glacial structures, e.g. buried valleys and a push moraine complex, are mapped down to 150 m below sea level. Below this rather horizontal features indicate Tertiary layers. Geophysically determined petrophysical values were correlated with lithological categories to enhance the interpretation of geophysical data. In this way, we expose

  5. Geology and Petrophysical Characterization of the Ferron Sandstone for 3-D Simulation of a Fluvial-Deltaic Reservoir

    SciTech Connect

    Ann Mattson; Craig B. Forster; Paul B. Anderson; Steve H. Snelgrove; Thomas C. Chidsey, Jr.

    1997-05-20

    The objective of this project is to develop a comprehensive, interdisciplinary, and quantitative characterization of a fluvial-deltaic reservoir which will allow realistic inter-well and reservoir-scale modeling to be constructed for improved oil-field development in similar reservoirs world-wide. The geological and petrophysical properties of the Cretaceous Ferron Sandstone in east-central Utah will be quantitatively determined. Both new and existing data will be integrated into a three-dimensional representation of spatial variations in porosity, storativity, and tensorial rock permeability at a scale appropriate for inter-well to regional-scale reservoir simulation. Four activities continued this quarter as part of the geological and petrophysical characterization of the fluvial-deltaic Ferron Sandstone in the Ivie Creek case-study area: (1) regional stratigraphic interpretation, (2) case-study evaluation, (3) reservoir modeling, and (4) technology transfer.

  6. Effective porosity and pore-throat sizes of Conasauga Group mudrock: Application, test and evaluation of petrophysical techniques

    SciTech Connect

    Dorsch, J.; Katsube, T.J.; Sanford, W.E. |; Dugan, B.E.; Tourkow, L.M.

    1996-04-01

    Effective porosity (specifically referring to the interconnected pore space) was recently recognized as being essential in determining the effectiveness and extent of matrix diffusion as a transport mechanism within fractured low-permeability rock formations. The research presented in this report was performed to test the applicability of several petrophysical techniques for the determination of effective porosity of fine-grained siliciclastic rocks. In addition, the aim was to gather quantitative data on the effective porosity of Conasauga Group mudrock from the Oak Ridge Reservation (ORR). The quantitative data reported here include not only effective porosities based on diverse measurement techniques, but also data on the sizes of pore throats and their distribution, and specimen bulk and grain densities. The petrophysical techniques employed include the immersion-saturation method, mercury and helium porosimetry, and the radial diffusion-cell method.

  7. Mapping of a buried basement combining aeromagnetic, gravity and petrophysical data: The substratum of southwest Paris Basin, France

    NASA Astrophysics Data System (ADS)

    Baptiste, Julien; Martelet, Guillaume; Faure, Michel; Beccaletto, Laurent; Reninger, Pierre-Alexandre; Perrin, José; Chen, Yan

    2016-06-01

    Aeromagnetic and gravity data have proven to be among the most effective methods for mapping deeply buried basin/basement interfaces. However, the data interpretation generally suffers from ambiguities, due to the non-uniqueness of the gravity and magnetic signatures. Here, we tie the gravity and magnetic signatures with a petrophysical characterization of the lithologies outcropping around the French Paris Basin. Our methodology investigates the lithology and structure of its hidden Variscan substratum at the junction between the Armorican Massif and Massif Central. Our approach is based on the combination of potential field data, magnetic susceptibilities measured in the field, density values of sample rocks and information documented in boreholes, in order to propose a new interpretative geological map of the buried substratum of the Paris Basin. The petrophysical description is combined with geophysical patterns of the substratum, mapped through statistical unsupervised classification of suitably selected magnetic and gravity maps. The first step of interpretation consists in extending the outcropping major structures below the Meso-Cenozoic sedimentary cover of the Paris Basin. The litho-structural units, in between these major structures, are then interpreted separately. The second step consists in assigning lithologies within each unit, with respect to its magnetization and density (as derived from the petrophysical compilation), and mapping its extension under cover, integrating punctual borehole information. Overall, with a special emphasis on relating geophysical signatures and petrophysical characteristics of litho-structural units, this methodology permits a precise structural and lithological cartography of a segment of the buried Variscan substratum. In the southwestern part of the Paris Basin, this approach reveals: i) the limited eastward extension of Central Brittany, ii) the eastward extension of the major Cholet fault, iii) the emphasis on N150E

  8. Relation between magnetic parameters and nematode abundance in agricultural soils of Portugal--a multidisciplinary study in the scope of environmental magnetism.

    PubMed

    Lourenço, Ana; Esteves, Ivânia; Rocha, Armando; Abrantes, Isabel; Gomes, Celeste

    2015-04-01

    Soil is composed of different types of particles which are either natural or of anthropogenic origin. Anthropogenic particles are often related to the presence of heavy metals and thus provide information on soil quality. Magnetic parameters can detect the presence of such particles and may be used as a proxy for environmental pollution. This study explores the relationships between magnetic particles and the nematofauna of agricultural soils. Magnetic, pedological, microscopy and nematological analyses were conducted in soils collected from major regions of potato production in Portugal. The magnetic characterisation of soils identified regions with magnetic particles with possible anthropogenic origin. Microscopy analysis revealed the presence of spherical particles dominantly composed of Fe, O and C. A positive and significant relationship was found between saturation isothermal remanent magnetisation (SIRM) and mass-specific susceptibility (χ), confirming the importance the ferrimagnetic fraction to magnetic properties. The nematode communities were composed of nematodes belonging to four trophic groups (bacterial feeding, plant feeders, fungal feeders and omnivores/predators). The relationships between magnetic parameters and the nematodes showed that (1) S-25 has a linear correlation with number of nematodes per kilogram of soil and with plant feeders' trophic group and (2) SIRM correlates with the bacterial feeders trophic group. This study reveals that magnetic proxies may provide means for detecting regions with higher levels of pollution, possibly related to heavy metals. Due to the large background variability found in magnetic parameters, the sampling spacial mesh should to be further refined and the input of magnetic minerals needs to be locally calibrated. PMID:25740688

  9. Relation between magnetic parameters and nematode abundance in agricultural soils of Portugal--a multidisciplinary study in the scope of environmental magnetism.

    PubMed

    Lourenço, Ana; Esteves, Ivânia; Rocha, Armando; Abrantes, Isabel; Gomes, Celeste

    2015-04-01

    Soil is composed of different types of particles which are either natural or of anthropogenic origin. Anthropogenic particles are often related to the presence of heavy metals and thus provide information on soil quality. Magnetic parameters can detect the presence of such particles and may be used as a proxy for environmental pollution. This study explores the relationships between magnetic particles and the nematofauna of agricultural soils. Magnetic, pedological, microscopy and nematological analyses were conducted in soils collected from major regions of potato production in Portugal. The magnetic characterisation of soils identified regions with magnetic particles with possible anthropogenic origin. Microscopy analysis revealed the presence of spherical particles dominantly composed of Fe, O and C. A positive and significant relationship was found between saturation isothermal remanent magnetisation (SIRM) and mass-specific susceptibility (χ), confirming the importance the ferrimagnetic fraction to magnetic properties. The nematode communities were composed of nematodes belonging to four trophic groups (bacterial feeding, plant feeders, fungal feeders and omnivores/predators). The relationships between magnetic parameters and the nematodes showed that (1) S-25 has a linear correlation with number of nematodes per kilogram of soil and with plant feeders' trophic group and (2) SIRM correlates with the bacterial feeders trophic group. This study reveals that magnetic proxies may provide means for detecting regions with higher levels of pollution, possibly related to heavy metals. Due to the large background variability found in magnetic parameters, the sampling spacial mesh should to be further refined and the input of magnetic minerals needs to be locally calibrated.

  10. Multi-targeted metagenetic analysis of the influence of climate and environmental parameters on soil microbial communities along an elevational gradient

    PubMed Central

    Lanzén, Anders; Epelde, Lur; Blanco, Fernando; Martín, Iker; Artetxe, Unai; Garbisu, Carlos

    2016-01-01

    Mountain elevation gradients are invaluable sites for understanding the effects of climate change on ecosystem function, community structure and distribution. However, relatively little is known about the impact on soil microbial communities, in spite of their importance for the functioning of the soil ecosystem. Previous studies of microbial diversity along elevational gradients were often limited by confounding variables such as vegetation, pH, and nutrients. Here, we utilised a transect in the Pyrenees established to minimise variation in such parameters, to examine prokaryotic, fungal, protist and metazoan communities throughout three consecutive years. We aimed to determine the influences of climate and environmental parameters on soil microbial community structure; as well as on the relationships between those microbial communities. Further, functional diversity of heterotrophic bacteria was determined using Biolog. Prokaryotic and fungal community structure, but not alpha-diversity, correlated significantly with elevation. However, carbon-to-nitrogen ratio and pH appeared to affect prokaryotic and protist communities more strongly. Both community structure and physicochemical parameters varied considerably between years, illustrating the value of long-term monitoring of the dynamic processes controlling the soil ecosystem. Our study also illustrates both the challenges and strengths of using microbial communities as indicators of potential impacts of climate change. PMID:27321429

  11. Multi-targeted metagenetic analysis of the influence of climate and environmental parameters on soil microbial communities along an elevational gradient

    NASA Astrophysics Data System (ADS)

    Lanzén, Anders; Epelde, Lur; Blanco, Fernando; Martín, Iker; Artetxe, Unai; Garbisu, Carlos

    2016-06-01

    Mountain elevation gradients are invaluable sites for understanding the effects of climate change on ecosystem function, community structure and distribution. However, relatively little is known about the impact on soil microbial communities, in spite of their importance for the functioning of the soil ecosystem. Previous studies of microbial diversity along elevational gradients were often limited by confounding variables such as vegetation, pH, and nutrients. Here, we utilised a transect in the Pyrenees established to minimise variation in such parameters, to examine prokaryotic, fungal, protist and metazoan communities throughout three consecutive years. We aimed to determine the influences of climate and environmental parameters on soil microbial community structure; as well as on the relationships between those microbial communities. Further, functional diversity of heterotrophic bacteria was determined using Biolog. Prokaryotic and fungal community structure, but not alpha-diversity, correlated significantly with elevation. However, carbon-to-nitrogen ratio and pH appeared to affect prokaryotic and protist communities more strongly. Both community structure and physicochemical parameters varied considerably between years, illustrating the value of long-term monitoring of the dynamic processes controlling the soil ecosystem. Our study also illustrates both the challenges and strengths of using microbial communities as indicators of potential impacts of climate change.

  12. Multi-targeted metagenetic analysis of the influence of climate and environmental parameters on soil microbial communities along an elevational gradient.

    PubMed

    Lanzén, Anders; Epelde, Lur; Blanco, Fernando; Martín, Iker; Artetxe, Unai; Garbisu, Carlos

    2016-01-01

    Mountain elevation gradients are invaluable sites for understanding the effects of climate change on ecosystem function, community structure and distribution. However, relatively little is known about the impact on soil microbial communities, in spite of their importance for the functioning of the soil ecosystem. Previous studies of microbial diversity along elevational gradients were often limited by confounding variables such as vegetation, pH, and nutrients. Here, we utilised a transect in the Pyrenees established to minimise variation in such parameters, to examine prokaryotic, fungal, protist and metazoan communities throughout three consecutive years. We aimed to determine the influences of climate and environmental parameters on soil microbial community structure; as well as on the relationships between those microbial communities. Further, functional diversity of heterotrophic bacteria was determined using Biolog. Prokaryotic and fungal community structure, but not alpha-diversity, correlated significantly with elevation. However, carbon-to-nitrogen ratio and pH appeared to affect prokaryotic and protist communities more strongly. Both community structure and physicochemical parameters varied considerably between years, illustrating the value of long-term monitoring of the dynamic processes controlling the soil ecosystem. Our study also illustrates both the challenges and strengths of using microbial communities as indicators of potential impacts of climate change. PMID:27321429

  13. Changes in fertility parameters and contents of heavy metals of soddy-podzolic soils upon the long-term application of sewage sludge

    NASA Astrophysics Data System (ADS)

    Vasbieva, M. T.; Kosolapova, A. I.

    2015-05-01

    The effect of the long-term sewage sludge (SS) application on the chemical, agrophysical, and biological properties of a soddy-podzolic soil ( Umbric Albeluvisols Abruptic) was studied. Regular SS application in the course of five crop rotations (1976-2013) ensured the improvement of the soil fertility parameters, i.e., a rise in the contents of humus, available phosphorus, and exchangeable potassium; a better state of the soil adsorption complex, bulk density, and aggregation; and higher cellulolytic, nitrification, and urease activities. The efficiencies of SS and the traditional organic fertilizer (cattle manure) were compared. The effect of the long-term application of SS on the accumulation of heavy metals in the soils was also studied. It was found that the application of SS caused a rise in the bulk content of heavy metals and in the contents of their acid-extractable and mobile forms by 1.1-6.0 times. However, the maximum permissible concentrations of heavy metals in the soils were not exceeded. In the soil subjected to the application of SS for more than 25 years, the cadmium concentration somewhat exceeded the maximum permissible concentration.

  14. The effects of environmental parameters on diffuse degassing at Stromboli volcano: Insights from joint monitoring of soil CO2 flux and radon activity

    NASA Astrophysics Data System (ADS)

    Laiolo, M.; Ranaldi, M.; Tarchini, L.; Carapezza, M. L.; Coppola, D.; Ricci, T.; Cigolini, C.

    2016-04-01

    Soil CO2 flux and 222Rn activity measurements may positively contribute to the geochemical monitoring of active volcanoes. The influence of several environmental parameters on the gas signals has been substantially demonstrated. Therefore, the implementation of tools capable of removing (or minimising) the contribution of the atmospheric effects from the acquired time series is a challenge in volcano surveillance. Here, we present 4 years-long continuous monitoring (from April 2007 to September 2011) of radon activity and soil CO2 flux collected on the NE flank of Stromboli volcano. Both gases record higher emissions during fall-winter (up to 2700 Bq * m- 3 for radon and 750 g m- 2 day- 1 for CO2) than during spring-summer seasons. Short-time variations on 222Rn activity are modulated by changes in soil humidity (rainfall), and changes in soil CO2 flux that may be ascribed to variations in wind speed and direction. The spectral analyses reveal diurnal and semi-diurnal cycles on both gases, outlining that atmospheric variations are capable to modify the gas release rate from the soil. The long-term soil CO2 flux shows a slow decreasing trend, not visible in 222Rn activity, suggesting a possible difference in the source depth of the of the gases, CO2 being deeper and likely related to degassing at depth of the magma batch involved in the February-April 2007 effusive eruption. To minimise the effect of the environmental parameters on the 222Rn concentrations and soil CO2 fluxes, two different statistical treatments were applied: the Multiple Linear Regression (MLR) and the Principal Component Regression (PCR). These approaches allow to quantify the weight of each environmental factor on the two gas species and show a strong influence of some parameters on the gas transfer processes through soils. The residual values of radon and CO2 flux, i.e. the values obtained after correction for the environmental influence, were then compared with the eruptive episodes that

  15. Comparison of petrophysical properties of impactites for four meteoritic impact structures

    NASA Astrophysics Data System (ADS)

    Popov, Y.; Mayr, S.; Romushkevich, R.; Burkhardt, H.; Wilhelm, H.

    2014-05-01

    We reanalyzed and compared unique data sets, which we obtained in the frame of combined petrophysical and geothermal investigations within scientific drilling projects on four impact structures: the Puchezh-Katunki impact structure (Vorotilovo borehole, Russia), the Ries impact structure (Noerdlingen-73 borehole, Germany), the Chicxulub impact structure (ICDP Yaxcopoil-1 borehole, Mexico), and the Chesapeake impact structure (ICDP-USGS-Eyreville borehole, USA). For a joined interpretation, we used the following previously published data: thermal properties, using the optical scanning technique, and porosities, both measured on densely sampled halfcores of the boreholes. For the two ICDP boreholes, we also used our previously published P-wave velocities measured on a subset of cores. We show that thermal conductivity, thermal anisotropy, porosity, and velocity can be correlated with shock metamorphism (target rocks of the Puchezh-Katunki and Ries impact structures), and confirm the absence of shock metamorphism in the samples taken from megablocks (Chicxulub and Chesapeake impact structure). The physical properties of the lithic impact breccias and suevites are influenced mainly by their impact-related porosity. Physical properties of lower porosity lithic impact breccias and suevites are also influenced by their chemical composition. These data allow for a distinction between different types of breccias due to differences concerning the texture and chemistry and the different amounts of melt and rock clasts.

  16. Petrophysical studies of north American carbonate rock samples and evaluation of pore-volume compressibility models

    NASA Astrophysics Data System (ADS)

    da Silva, Gilberto Peixoto; Franco, Daniel R.; Stael, Giovanni C.; da Costa de Oliveira Lima, Maira; Sant'Anna Martins, Ricardo; de Moraes França, Olívia; Azeredo, Rodrigo B. V.

    2015-12-01

    In this work, we evaluate two pore volume compressibility models that are currently discussed in the literature (Horne, 1990; Jalalh, 2006b). Five groups of carbonate rock samples from the three following sedimentary basins in North America that are known for their association with hydrocarbon deposits were selected for this study: (i) the Guelph Formation of the Michigan Basin (Middle Silurian); (ii) the Edwards Formation of the Central Texas Platform (Middle Cretaceous); and (iii) the Burlington-Keokuk Formation of the Mississippian System (Lower Mississippian). In addition to the evaluation of the compressibility model, a petrophysical evaluation of these rock samples was conducted. Additional characterizations, such as grain density, the effective porosity, absolute grain permeability, thin section petrography, MICP and NMR, were performed to complement constant pore-pressure compressibility tests. Although both models presented an overall good representation of the compressibility behavior of the studied carbonate rocks, even when considering their broad porosity range (~ 2-38%), the model proposed by Jalalh (2006b) performed better with a confidence level of 95% and a prediction interval of 68%.

  17. Estimation of petrophysical and fluid properties using integral transforms in nuclear magnetic resonance.

    PubMed

    Gruber, Fred K; Venkataramanan, Lalitha; Habashy, Tarek M; Freed, Denise E

    2013-03-01

    In the past decade, low-field NMR relaxation and diffusion measurements in grossly inhomogeneous fields have been used to characterize properties of porous media, e.g., porosity and permeability. Pulse sequences such as CPMG, inversion and saturation recovery as well as diffusion editing have been used to estimate distribution functions of relaxation times and diffusion. Linear functionals of these distribution functions have been used to predict petro-physical and fluid properties like permeability, viscosity, fluid typing, etc. This paper describes an analysis method using integral transforms to directly compute linear functionals of the distributions of relaxation times and diffusion without first computing the distributions from the measured magnetization data. Different linear functionals of the distribution function can be obtained by choosing appropriate kernels in the integral transforms. There are two significant advantages of this approach over the traditional algorithm involving inversion of the distribution function from the measured data. First, it is a direct linear transform of the data. Thus, in contrast to the traditional analysis which involves inversion of an ill-conditioned, non-linear problem, the estimates from this new method are more accurate. Second, the uncertainty in the linear functional can be obtained in a straight-forward manner as a function of the signal-to-noise ratio (SNR) in the measured data. We demonstrate the performance of this method on simulated data. PMID:23369701

  18. Petrophysics of low-permeability medina sandstone, northwestern Pennsylvania, Appalachian Basin

    USGS Publications Warehouse

    Castle, J.W.; Byrnes, A.P.

    1998-01-01

    Petrophysical core testing combined with geophysical log analysis of low-permeability, Lower Silurian sandstones of the Appalachian basin provides guidelines and equations for predicting gas producibility. Permeability values are predictable from the borehole logs by applying empirically derived equations based on correlation between in-situ porosity and in-situ effective gas permeability. An Archie-form equation provides reasonable accuracy of log-derived water saturations because of saturated brine salinities and low clay content in the sands. Although measured porosity and permeability average less than 6% and 0.1 mD, infrequent values as high as 18% and 1,048 mD occur. Values of effective gas permeability at irreducible water saturation (Swi) range from 60% to 99% of routine values for the highest permeability rocks to several orders of magnitude less for the lowest permeability rocks. Sandstones having porosity greater than 6% and effective gas permeability greater than 0.01 mD exhibit Swi less than 20%. With decreasing porosity, Swi sharply increases to values near 40% at 3 porosity%. Analysis of cumulative storage and flow capacity indicates zones with porosity greater than 6% generally contain over 90% of flow capacity and hold a major portion of storage capacity. For rocks with Swi < 20%, gas relative permeabilities exceed 45%. Gas relative permeability and hydrocarbon volume decrease rapidly with increasing Swi as porosity drops below 6%. At Swi above 40%, gas relative permeabilities are less than approximately 10%.

  19. Diagenetic evolution and petrophysical characteristics of oomoldic facies in United States and Middle East reservoirs

    SciTech Connect

    Nurmi, R.; Neuberger, D.

    1987-08-01

    The diagenetic evolution of oomoldic pore rocks from US and Middle East reservoirs were studied to determine their variation. The oomolds in all of the reservoir samples appear to have formed prior to any compaction, and were also subject to early cementation, which preserved the delicate structure of these rocks. The most common oomold-filling mineral is calcite, regardless of whether the remainder of the rock is dolostone or limestone. Anhydrite is commonly the mineral filling oomolds in formations depositionally associated with evaporites. Partial cementation of individual oomolds is rare. However, partial filling of oomoldic wackestones by lime mud was observed. The petrophysical characteristics of oomoldic rocks in different stages of diagenetic evolution were analyzed using thin sections, pore casts, porosity and permeability measurements, and saturation. The rocks used in the study included core samples from the Lansing-Kansas City Group, San Andres, Smackover, Arab, and Khuff formations. Selected samples from the Lansing-Kansas City Groups were also measured for formation factor, density, and for dielectric and acoustic properties. The study quantified the relationship of pore type and volume with both formation factor and permeability of oomoldic rocks. The framework mineralogy (calcite or dolomite) and microstructure, and the presence and nature of interparticle pore-filling cements are critical factors in assessing the reservoir potential of an oomoldic reservoir facies. Furthermore, the geologic analysis of the pore system can greatly improve the determination of the Archie m exponent, which provides more reasonable evaluations of the saturation and permeability of these complex rocks.

  20. Computational challenges in the analyses of petrophysics using microtomography and upscaling: A review

    NASA Astrophysics Data System (ADS)

    Liu, Jie; Pereira, Gerald G.; Liu, Qingbin; Regenauer-Lieb, Klaus

    2016-04-01

    Microtomography provides detailed 3D internal structures of materials in micro- to tens of nano-meter resolution and is quickly turning into a new technology for studying petrophysical properties of rocks. An important step is the upscaling of these properties as micron or sub-micron resolution can only be achieved on the sample-scale of millimeters or even less than a millimeter. We have developed a computational workflow for the analysis of microstructures including the upscaling of material properties. Computations of properties are first performed using conventional material science simulations at micro to nano-scale. The subsequent upscaling of these properties is done by a novel renormalization procedure based on percolation theory. In this paper we discuss the computational challenges arising from the workflow, which include: 1) characterization of microtomography for extremely large data sets; 2) computational fluid dynamics simulations at pore-scale for permeability estimation; 3) solid mechanical computations at pore-scale for estimating elasto-plastic properties; 4) Extracting critical exponents from derivative models for scaling laws. We conclude that significant progress in each of these challenges is necessary to transform microtomography from the current research problem into a robust computational big data tool for multi-scale scientific and engineering problems.

  1. Effects of natural and chemical stressors on Enchytraeus albidus: can oxidative stress parameters be used as fast screening tools for the assessment of different stress impacts in soils?

    PubMed

    Howcroft, C F; Amorim, M J B; Gravato, C; Guilhermino, L; Soares, A M V M

    2009-02-01

    Enchytraeids are important organisms of the soil biocenosis. They improve the soil pore structure and the degradation of organic matter. These organisms are used in standardized testing, using survival and reproduction (6 weeks) as endpoints. The use of biomarkers, linked to ecologically relevant alterations at higher levels of biological organization, is a promising tool for Environmental Risk Assessment. Here, enchytraeids were exposed for different time periods (two days and three weeks) to different soils (OECD artificial soil, different compositions in its organic matter, clay or pH value, and LUFA 2.2 natural soil) and different chemicals (Phenmedipham and copper). The main question addressed in the present study was if the effects of chemicals and different soil properties are preceded by alterations at the sub-cellular level, and if these endpoints may be used reliantly as faster screening tools for the assessment of different stress conditions in soils. The parameters measured in E. albidus whole body were: lipid peroxidation (LPO), total glutathione (TG), as well as the enzymatic activities of superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPx) and glutathione S-transferase (GST). The results showed that biomarker responses in E. albidus were significantly affected by the soil type (GST, CAT, GPx, GR and LPO) and the duration of exposure in OECD artificial soil (GST, GPx, GR, CAT and LPO) but not in LUFA 2.2 natural soil. For the abiotic factors studied, after 2 days, low pH decreased significantly the TG levels and the activities of CAT and GR,and low OM also significantly decreased CAT and GR activities. After 3 weeks, differences in soil properties caused a decrease in GR and GPx activities, whereas increased GST activity was observed due to low organic matter and pH. Copper significantly increased the activities of CAT, GPx and GR, and decreased the activity of GST after 2 days as well as inscreasing

  2. Mapping of soil erosion and redistribution on two agricultural areas in Czech Republic by using of magnetic parameters.

    NASA Astrophysics Data System (ADS)

    Kapicka, Ales; Stejskalova, Sarka; Grison, Hana; Petrovsky, Eduard; Jaksik, Ondrej; Kodesova, Radka

    2015-04-01

    Soil erosion is one of the major concerns in sustainability of agricultural systems in different areas. Therefore there is a need to develop suitable innovative indirect methods of soil survey. One of this methods is based on well established differentiation in magnetic signature with depth in soil profile. Magnetic method can be applied in the field as well as in the laboratory on collected soil samples. The aim of this study is to evaluate suitability of magnetic method to assess soil degradation and construct maps of cumulative soil loss due to erosion at two morphologically diverse areas with different soil types. Dominant soil unit in the first locality (Brumovice) is chernozem, which is gradually degraded on slopes to regosols. In the second site (Vidim), the dominant soil unit is luvisol, gradualy transformed to regosol due to erosion. Field measurements of magnetic susceptibility were carried out on regular grid, resulting in 101 data points in Brumovice and 65 in Vidim locality. Mass specific magnetic susceptibility χ and its frequency dependence χFD was used to estimate the significance of SP ferrimagnetic particles of pedogenic origin in top soil horizons. Strong correlation was found between the volume magnetic susceptibility (field measurement) and mass- specific magnetic susceptibility measured in the laboratory (Kapicka et al 2013). Values of magnetic susceptibility are spatially distributed depending on terrain position. Higher values were measured at the flat parts (where the original topsoil horizon remained). The lowest values magnetic susceptibility were obtained on the steep valley sides. Here the original topsoil was eroded and mixed by tillage with the soil substrate (loess). Positive correlation between the organic carbon content and volume magnetic susceptibility (R2= 0.89) was found for chernozem area. The differences between the values of susceptibility in the undisturbed soil profile and the magnetic signal after uniform mixing of the

  3. Different scenarios for inverse estimation of soil hydraulic parameters from double-ring infiltrometer data using HYDRUS-2D/3D

    NASA Astrophysics Data System (ADS)

    Mashayekhi, Parisa; Ghorbani-Dashtaki, Shoja; Mosaddeghi, Mohammad Reza; Shirani, Hossein; Nodoushan, Ali Reza Mohammadi

    2016-04-01

    In this study, HYDRUS-2D/3D was used to simulate ponded infiltration through double-ring infiltrometers into a hypothetical loamy soil profile. Twelve scenarios of inverse modelling (divided into three groups) were considered for estimation of Mualem-van Genuchten hydraulic parameters. In the first group, simulation was carried out solely using cumulative infiltration data. In the second group, cumulative infiltration data plus water content at h = -330 cm (field capacity) were used as inputs. In the third group, cumulative infiltration data plus water contents at h = -330 cm (field capacity) and h = -15 000 cm (permanent wilting point) were used simultaneously as predictors. The results showed that numerical inverse modelling of the double-ring infiltrometer data provided a reliable alternative method for determining soil hydraulic parameters. The results also indicated that by reducing the number of hydraulic parameters involved in the optimization process, the simulation error is reduced. The best one in infiltration simulation which parameters α, n, and Ks were optimized using the infiltration data and field capacity as inputs. Including field capacity as additional data was important for better optimization/definition of soil hydraulic functions, but using field capacity and permanent wilting point simultaneously as additional data increased the simulation error.

  4. Exploring Critical Assumptions of Petrophysical Models in Fractured Aquifers by Comparing Estimated Porosity Values Obtained from Surface Nuclear Magnetic Resonance and Shallow Seismic Refraction Surveys.

    NASA Astrophysics Data System (ADS)

    Flinchum, B. A.; Holbrook, W. S.; Grana, D.; Parsekian, A.

    2015-12-01

    Estimating subsurface porosity from most near-surface geophysical techniques relies on petrophysical relationships. Using petrophysical relationships are challenging because they require many assumptions and oftentimes require site-specific constants. Despite complexities and challenges, the petrophysical relationships are critical to convert the measurable physical properties into hydrologic properties such as porosity, water content and ultimately hydraulic conductivity. In this study we compare porosities derived from shallow seismic refraction (SSR) and surface nuclear magnetic resonance (SNMR) in a fractured granite aquifer in the Laramie Range, Wyoming. To estimate porosity from the SSR data we use a Bayesian inversion based on Hertz-Mindlin contact theory and Hashin- Strickman boundaries. This type of petrophysical model requires us to make assumptions about the grain structure, mineralogy and water content. Using water table measurements from a borehole we assume that all pores are fully saturated below 10 meters, thus the SNMR measurement provides an estimate of porosity. If the petrophysical model and the assumptions that are required to use it were correct and the SNMR measurements were perfect, the estimates of porosities derived from two distinct physical measurements should provide the same porosity. Interestingly, we observe a large discrepancy in the porosities derived from this unique combination of measurements. At depths of 10 to 20 meters, the area that we interpret as fractured bedrock and where the assumption of fully saturated pores holds, the SSR predicted porosities are 15 to 20 % higher than those predicted by SNMR. Previous comparisons of the Bayesian inversion have shown it does well to predict porosity within the saprolite. The large discrepancy illustrates the need to use separate petrophysical models in the weathered and fractured zones of granite aquifers. More research is needed to figure out how to combine different petrophysical

  5. Modeling the uncertainty in responsiveness of climatic, genetic, soil and agronomic parameters in CERES-Sorghum model across locations in Kansas, USA

    NASA Astrophysics Data System (ADS)

    Lamsal, A.; Anandhi, A.; Welch, S.

    2012-12-01

    Kansas leads grain sorghum production in the USA. Crop models are useful tools which provide insight about the functioning of crops, agricultural systems, and their interactions. There is a temperature and precipitation gradient across Kansas. The CERES-Sorghum model in the DSSAT system (Decision Support System for Agro-transfer Technology) was applied to many locations within the state. We hypothesize that the degree of responsiveness to CERES-Sorghum parameters would vary due to these gradients. The objective of this study is to document the uncertainties in the responsiveness of the climatic, genetic, soil and agronomic parameters in CERES-Sorghum across many locations in Kansas using multiple response variables. The input parameter categories evaluated are: climatic (temperature, solar radiation, rainfall, and CO2); genetic (P1, P2O, P5, G2, G5); agronomic (planting date, planting depth, row spacing and plant population); and soil (drained upper limit, drained lower limit, pH, saturated water content, soil organic carbon, bulk density, runoff curve number and drainage rate). Uncertainty analysis was carried out for six output response variables (yield, biomass, anthesis days, maturity days, leaf area index and leaf number) Sensitivity analysis was carried out using the OAT (one at a time) method by perturbing one input at a time keeping rest of the input parameter constant. Both relative sensitivity (a mathematical approach) and a graphical method were used, Cumulative distribution functions were used for uncertainty analysis. Preliminary results showed that, responsiveness of input parameters varied with input parameters, response variable, and location.

  6. Influence of petrophysical parameters on eruption dynamics: a rheological study of the erupted products of Mt. Yasur, Vanuatu

    NASA Astrophysics Data System (ADS)

    Hanson, J. B.; Kremers, S. B.; Lavallee, Y.; Hess, K.; Dingwell, D. B.

    2011-12-01

    Mt. Yasur (Tanna, Vanuatu) is a small scoria cone (360 m high) and one of the most persistently active volcanoes worldwide. During the last ~10.000 years, Mt.Yasur mostly produced strong strombolian to vulcanian eruptions intercalated by sub-plinian eruptions every ca. 40 years. During a 6-week field campaign in August-September 2008, we installed four seismic and four infrasound arrays on site to record seismic and acoustic signals. Two Doppler-Radars measured the exit velocities of the erupted material, and a thermal camera was used to determine the temperature at the vent mouth. At the time of the fieldwork, three active craters showed very different styles of activity. Crater A, the most active vent, had an eruption recurrence of under a minute. Crater B showed very irregular ash-venting, while crater C was producing the strongest eruptions every 10 minutes. We sampled the eruptive products of craters A and C for further analysis in the lab. In total, three bombs were collected in order to investigate the chemical, physical, rheological and textural variations in the erupted products from the different craters. The collected basaltic-andesite scoria bombs exhibit a relatively constant whole rock major element geochemistry (~56 wt.% SiO2); correspondingly, the remelted whole rock viscosity, investigated via a combination of concentric cylinder rheometry and micropenetration, remains similar. Petrographic texture and structure analyses reveal a large variation in porosity (~30 - 78 %) and microlite content. Observation of aphyric zones grading abruptly or incrementally (on mm to cm scales) to nearly entirely crystalline zones suggest the occurrence of mingling and mixing of magma batches with different crystallization histories. The microlites are mostly anhydral, showing and needle-like growth pattern, with signs of kinetic growth disequilibrium similar to spherulites. Interstitial glass chemistry from electron microprobe analysis shows a range of glass chemistry from 59-63 wt.% SiO2, with less-evolved glass generally being associated with areas of higher crystal content. Combining the estimation of the calorimetric glass transition temperature at (600 °C at 10 °C/min) with the observed crystal growth disequilibrium emphasizes the proximity of the eruptive temperature conditions to the glass transition interval. We discuss the potential distinction in eruptive behaviour from the variation in crystal assemblages and rheologies.

  7. Soil Parameter Mapping and Ad Hoc Power Analysis to Increase Blocking Efficiency Prior to Establishing a Long-Term Field Experiment.

    PubMed

    Collins, Doug; Benedict, Chris; Bary, Andy; Cogger, Craig

    2015-01-01

    The spatial heterogeneity of soil and weed populations poses a challenge to researchers. Unlike aboveground variability, below-ground variability is more difficult to discern without a strategic soil sampling pattern. While blocking is commonly used to control environmental variation, this strategy is rarely informed by data about current soil conditions. Fifty georeferenced sites were located in a 0.65 ha area prior to establishing a long-term field experiment. Soil organic matter (OM) and weed seed bank populations were analyzed at each site and the spatial structure was modeled with semivariograms and interpolated with kriging to map the surface. These maps were used to formulate three strategic blocking patterns and the efficiency of each pattern was compared to a completely randomized design and a west to east model not informed by soil variability. Compared to OM, weeds were more variable across the landscape and had a shorter range of autocorrelation, and models to increase blocking efficiency resulted in less increase in power. Weeds and OM were not correlated, so no model examined improved power equally for both parameters. Compared to the west to east blocking pattern, the final blocking pattern chosen resulted in a 7-fold increase in power for OM and a 36% increase in power for weeds.

  8. Soil Parameter Mapping and Ad Hoc Power Analysis to Increase Blocking Efficiency Prior to Establishing a Long-Term Field Experiment

    PubMed Central

    Collins, Doug; Benedict, Chris; Bary, Andy; Cogger, Craig

    2015-01-01

    The spatial heterogeneity of soil and weed populations poses a challenge to researchers. Unlike aboveground variability, below-ground variability is more difficult to discern without a strategic soil sampling pattern. While blocking is commonly used to control environmental variation, this strategy is rarely informed by data about current soil conditions. Fifty georeferenced sites were located in a 0.65 ha area prior to establishing a long-term field experiment. Soil organic matter (OM) and weed seed bank populations were analyzed at each site and the spatial structure was modeled with semivariograms and interpolated with kriging to map the surface. These maps were used to formulate three strategic blocking patterns and the efficiency of each pattern was compared to a completely randomized design and a west to east model not informed by soil variability. Compared to OM, weeds were more variable across the landscape and had a shorter range of autocorrelation, and models to increase blocking efficiency resulted in less increase in power. Weeds and OM were not correlated, so no model examined improved power equally for both parameters. Compared to the west to east blocking pattern, the final blocking pattern chosen resulted in a 7-fold increase in power for OM and a 36% increase in power for weeds. PMID:26247056

  9. Development of Site-Specific Soil Design Basis Earthquake (DBE) Parameters for the Integrated Waste Treatment Unit (IWTU)

    SciTech Connect

    Payne, Suzette

    2008-08-01

    Horizontal and vertical PC 3 (2,500 yr) Soil Design Basis Earthquake (DBE) 5% damped spectra, corresponding time histories, and strain-compatible soil properties were developed for the Integrated Waste Treatment Unit (IWTU). The IWTU is located at the Idaho Nuclear Technology and Engineering Center (INTEC) at the Idaho National Laboratory (INL). Mean and 84th percentile horizontal DBE spectra derived from site-specific site response analyses were evaluated for the IWTU. The horizontal and vertical PC 3 (2,500 yr) Soil DBE 5% damped spectra at the 84th percentile were selected for Soil Structure Interaction (SSI) analyses at IWTU. The site response analyses were performed consistent with applicable Department of Energy (DOE) Standards, recommended guidance of the Nuclear Regulatory Commission (NRC), American Society of Civil Engineers (ASCE) Standards, and recommendations of the Blue Ribbon Panel (BRP) and Defense Nuclear Facilities Safety Board (DNFSB).

  10. Light intensity and production parameters of phytocenoses cultivated on soil-like substrate under controled environment conditions

    NASA Astrophysics Data System (ADS)

    Tikhomirov, A.; Ushakova, S.; Gribovskaya, I.; Tirranen, L.; Manukovsky, N.; Zolotukhin, I.

    To investigate feasibility of enhancing closedness in a new generation of biological life support systems (LSS) to involve the inedible phytomass into intrasystem mass exchange the vermicomposting method we have chosen made possible to produce soil-like substrate (SLS) suitable for growing plants. However, to use the SLS in life support systems call for investigation of its physical, chemical and other parameters. Of special importance among them is the capacity of SLS to provide the LSS photosynthesizing component with required mineral elements in selected cultivation conditions. In this connection the aim of this work was to study opportunities of enhancing pr4oduction activity of wheat and radish cenoses by varying the intensity of photosynthetically active radiation (PAR) without decreasing the harvest index. Increase of light intensity to 250 W/m 2 PAR decreased the intensity of visible photosynthesis of wheat cenosi and slightly increased visible photosynthesis of radish cenosis as compared to 200 W/m 2 PAR. The maximum productivity of wheat cenosis both total and seeds corresponded to the irradiance of 200 W/m 2 PAR. The light intensity of 250 W/m2 PAR decreased productivity of wheat plants and had no significant effect of the productivity of radish cenosis as compared to 200 W/m 2 PAR. Qualitative and quantitative composition of microflora of the watering solution and SLS was determined by the condition of plants, development phase and PAR intensity. By the end of wheat vegetation under 250 W/m 2 there were an order more bacteria of the colon rod group and phytopathogenic bacteria in the watering solution and SLS than under other illumination conditions. Investigation of the mineral composition of SLS and the watering solution demonstrated that one of the reasons of inadequate response of the cenosis under study to elevated PAR intensity may be deficiency of accessible forms of some mineral elements, e.g. nitrogen. The above said materials evidence that

  11. Exploring the sensitivity on a soil area-slope-grading relationship to changes in process parameters using a pedogenesis model

    NASA Astrophysics Data System (ADS)

    Welivitiya, W. D. Dimuth P.; Willgoose, Garry R.; Hancock, Greg R.; Cohen, Sagy

    2016-08-01

    This paper generalises the physical dependence of the relationship between contributing area, local slope, and the surface soil grading using a pedogenesis model and allows an exploration of soilscape self-organisation. A parametric study was carried out using different parent materials, erosion, and weathering mechanisms. These simulations confirmed the generality of the area-slope-d50 relationship. The relationship is also true for other statistics of soil grading (e.g. d10,d90) and robust for different depths within the profile. For small area-slope regimes (i.e. hillslopes with small areas and/or slopes) only the smallest particles can be mobilised by erosion and the area-slope-d50 relationship appears to reflect the erosion model and its Shield's Stress threshold. For higher area-slope regimes, total mobilization of the entire soil grading occurs and self-organisation reflects the relative entrainment of different size fractions. Occasionally the interaction between the in-profile weathering and surface erosion draws the bedrock to the surface and forms a bedrock outcrop. The study also shows the influence on different depth-dependent in-profile weathering functions in the formation of the equilibrium soil profile and the grading characteristics of the soil within the profile. We outline the potential of this new model and its ability to numerically explore soil and landscape properties.

  12. Petrophysical Properties of Twenty Drill Cores from the Los Azufres, Mexico, Geothermal Field

    SciTech Connect

    Iglesias, E.R.; Contreras L., E.; Garcia G., A.; Dominquez A., Bernardo

    1987-01-20

    For this study we selected 20 drill cores covering a wide range of depths (400-3000 m), from 15 wells, that provide a reasonable coverage of the field. Only andesite, the largely predominant rock type in the field, was included in this sample. We measured bulk density, grain (solids) density, effective porosity and (matrix) permeability on a considerable number of specimens taken from the cores; and inferred the corresponding total porosity and fraction of interconnected total porosity. We characterized the statistical distributions of the measured and inferred variables. The distributions of bulk density and grain density resulted approximately normal; the distributions of effective porosity, total porosity and fraction of total porosity turned out to be bimodal; the permeability distribution resulted highly skewed towards very small (1 mdarcy) values, though values as high as 400 mdarcies were measured. We also characterized the internal inhomogeneity of the cores by means of the ratio (standard deviation/mean) corresponding to the bulk density in each core (in average there are 9 specimens per core). The cores were found to present clearly discernible inhomogeneity; this quantitative characterization will help design new experimental work and interpret currently available and forthcoming results. We also found statistically significant linear correlations between total density and density of solids, effective porosity and total density, total porosity and total density, fraction of interconnected total porosity and the inverse of the effective porosity, total porosity and effective porosity; bulk density and total porosity also correlate with elevation. These results provide the first sizable and statistically detailed database available on petrophysical properties of the Los Azufres andesites. 1 tab., 16 figs., 4 refs.

  13. Petrophysical models of high velocity lower crust on the South Atlantic rifted margins: whence the asymmetry?

    NASA Astrophysics Data System (ADS)

    Trumbull, Robert B.; Franke, Dieter; Bauer, Klaus; Sobolev, Stephan V.

    2015-04-01

    Lower crustal bodies with high seismic velocity (Vp > 7km/s) underlie seaward-dipping reflector wedges on both margins of the South Atlantic, as on many other volcanic rifted margins worldwide. A comprehensive geophysical study of the South Atlantic margins by Becker et al. (Solid Earth, 5: 1011-1026, 2014) showed a strong asymmetry in the development of high-velocity lower crust (HVLC), with about 4 times larger volumes of HVLC on the African margin. That study also found interesting variations in the vertical position of HVLC relative to seaward-dipping reflectors which question a simple intrusive vs. extrusive relationship between these lower- and upper crustal features. The asymmetry of HVLC volumes on the conjugate margins is paradoxically exactly the opposite to that of surface lavas in the Paraná-Etendeka flood basalt province, which are much more voluminous on the South American margin. This contribution highlights the asymmetric features of magma distribution on the South Atlantic margins and explores their geodynamic significance. Petrophysical models of the HVLC are presented in the context of mantle melt generation, based on thickness-velocity (H-Vp) relations. These suggest that the greater volumes and average Vp values of HVLC on the African margin are due to active upwelling and high temperature, whereas passive upwelling under a thick lithospheric lid suppressed magma generation on the South American margin. The contrast in mantle upwelling rate and lithospheric thickness on the two margins predictably causes differential uplift, and this may help explain the greater accomodation space for surface lavas on the South American side although melt generation was strongest under the African margin.

  14. Petrophysical properties of saprolites from the Oak Ridge Integrated Field Research Challenge site, Tennessee

    SciTech Connect

    Revil, André; Skold, Magnus; Hubbard, Susan S.; Wu, Yuxin; Watson, David B.; Karaoulis, Marios

    2013-01-01

    At the Oak Ridge Integrated Field Research Challenge site, near Oak Ridge, Tennessee, the shallow saprolitic aquifer is contaminated by nitric acid, uranium, and metals originating from the former S3 settling ponds. To interpret low-frequency geophysical methods used to image contaminant plumes, we have characterized the petrophysical properties of three representative saprolite core samples. Their hydraulic conductivity ranges from to in agreement with field data. Complex conductivity measurements, in the frequency range of 1 mHz to 45 kHz, were performed with NaCl solutions with electrical conductivities in the range to , a range representative of field conditions. The electrical conductivity data were well reproduced with a simple linear conductivity model between the saprolite conductivity and the pore water conductivity. The conductivity plots were used to estimate the formation factor (the cementation exponent was about ) and the surface conductivity ( ). The magnitude of the surface conductivity depended on the degree of weathering and therefore on the amount of smectite and mixed layer (illite-smectite) clays present in the saprolite. The chargeability of the core samples was in the range of and is strongly dependent on the salinity. We also performed streaming potential measurements with the same pore fluid composition as that used for the complex conductivity measurements. We found an excess of movable electrical charges on the order of 100 to in agreement with previous investigations connecting the movable excess charge density to permeability. The zeta potential was in the range of to independent on the salinity. The electrical measurements were consistent with an average cation exchange capacity in the range of 1.4 to and a specific surface area on the order of 4000 to about 30,000 . Read More: http://library.seg.org/doi/abs/10.1190/geo2012-0176.1

  15. Petrofacies analysis - the petrophysical tool for geologic/engineering reservoir characterization

    SciTech Connect

    Watney, W.L.; Guy, W.J.; Gerlach, P.M.

    1997-08-01

    Petrofacies analysis is defined as the characterization and classification of pore types and fluid saturations as revealed by petrophysical measures of a reservoir. The word {open_quotes}petrofacies{close_quotes} makes an explicit link between petroleum engineers concerns with pore characteristics as arbiters of production performance, and the facies paradigm of geologists as a methodology for genetic understanding and prediction. In petrofacies analysis, the porosity and resistivity axes of the classical Pickett plot are used to map water saturation, bulk volume water, and estimated permeability, as well as capillary pressure information, where it is available. When data points are connected in order of depth within a reservoir, the characteristic patterns reflect reservoir rock character and its interplay with the hydrocarbon column. A third variable can be presented at each point on the crossplot by assigning a color scale that is based on other well logs, often gamma ray or photoelectric effect, or other derived variables. Contrasts between reservoir pore types and fluid saturations will be reflected in changing patterns on the crossplot and can help discriminate and characterize reservoir heterogeneity. Many hundreds of analyses of well logs facilitated by spreadsheet and object-oriented programming have provided the means to distinguish patterns typical of certain complex pore types for sandstones and carbonate reservoirs, occurrences of irreducible water saturation, and presence of transition zones. The result has been an improved means to evaluate potential production such as bypassed pay behind pipe and in old exploration holes, or to assess zonation and continuity of the reservoir. Petrofacies analysis is applied in this example to distinguishing flow units including discrimination of pore type as assessment of reservoir conformance and continuity. The analysis is facilitated through the use of color cross sections and cluster analysis.

  16. The application of petrophysics to resolve fluid flow units and reservoir quality in the Upper Cretaceous Formations: Abu Sennan oil field, Egypt

    NASA Astrophysics Data System (ADS)

    Lala, Amir Maher Sayed; El-sayed, Nahla Abd El-Aziz

    2015-02-01

    Petrophysical flow unit concept can be used to resolve some of the key challenges faced in the characterization of hydrocarbon reservoirs. The present study deals with petrophysical evaluation of some physical properties of the Upper Cretaceous rock samples obtained from the Abu-Roash and the Bahariya Formations at southwest of Sennan oil field in the Western Desert of Egypt. The aim of this study was achieved through carrying out some petrophysical measurements of porosity, bulk density, permeability, mean hydraulic radius (Rh), irreducible water saturation, and radius of pore throat at mercury saturation of 35% in order to determine reservoir characteristics. In this study, the relationships obtained between the measured petrophysical properties such as porosity, permeability and pore throat flow unit types were established for 53 sandstone core samples obtained from two different stratigraphic units. Flow zone indicator (FZI) has been calculated to quantify the flow character of the Abu-Roash and Bahariya reservoir rocks based on empirically derived equations of robust correlation coefficients. The correlations among porosity, permeability, bulk density, mean hydraulic radius and pore throat flow properties reflect the most important reservoir behavior characteristics. The calculated multiple regression models indicate close correlation among petrophysical properties and Rh and R35%. The obtained models are able to predict Rh and R35% by using porosity and permeability, to map reservoir performance and predict the location of stratigraphic traps.

  17. A Novel Low-Cost Open-Hardware Platform for Monitoring Soil Water Content and Multiple Soil-Air-Vegetation Parameters

    PubMed Central

    Bitella, Giovanni; Rossi, Roberta; Bochicchio, Rocco; Perniola, Michele; Amato, Mariana

    2014-01-01

    Monitoring soil water content at high spatio-temporal resolution and coupled to other sensor data is crucial for applications oriented towards water sustainability in agriculture, such as precision irrigation or phenotyping root traits for drought tolerance. The cost of instrumentation, however, limits measurement frequency and number of sensors. The objective of this work was to design a low cost “open hardware” platform for multi-sensor measurements including water content at different depths, air and soil temperatures. The system is based on an open-source ARDUINO microcontroller-board, programmed in a simple integrated development environment (IDE). Low cost high-frequency dielectric probes were used in the platform and lab tested on three non-saline soils (ECe1: 2.5 < 0.1 mS/cm). Empirical calibration curves were subjected to cross-validation (leave-one-out method), and normalized root mean square error (NRMSE) were respectively 0.09 for the overall model, 0.09 for the sandy soil, 0.07 for the clay loam and 0.08 for the sandy loam. The overall model (pooled soil data) fitted the data very well (R2 = 0.89) showing a high stability, being able to generate very similar RMSEs during training and validation (RMSEtraining = 2.63; RMSEvalidation = 2.61). Data recorded on the card were automatically sent to a remote server allowing repeated field-data quality checks. This work provides a framework for the replication and upgrading of a customized low cost platform, consistent with the open source approach whereby sharing information on equipment design and software facilitates the adoption and continuous improvement of existing technologies. PMID:25337742

  18. A novel low-cost open-hardware platform for monitoring soil water content and multiple soil-air-vegetation parameters.

    PubMed

    Bitella, Giovanni; Rossi, Roberta; Bochicchio, Rocco; Perniola, Michele; Amato, Mariana

    2014-10-21

    Monitoring soil water content at high spatio-temporal resolution and coupled to other sensor data is crucial for applications oriented towards water sustainability in agriculture, such as precision irrigation or phenotyping root traits for drought tolerance. The cost of instrumentation, however, limits measurement frequency and number of sensors. The objective of this work was to design a low cost "open hardware" platform for multi-sensor measurements including water content at different depths, air and soil temperatures. The system is based on an open-source ARDUINO microcontroller-board, programmed in a simple integrated development environment (IDE). Low cost high-frequency dielectric probes were used in the platform and lab tested on three non-saline soils (ECe1: 2.5 < 0.1 mS/cm). Empirical calibration curves were subjected to cross-validation (leave-one-out method), and normalized root mean square error (NRMSE) were respectively 0.09 for the overall model, 0.09 for the sandy soil, 0.07 for the clay loam and 0.08 for the sandy loam. The overall model (pooled soil data) fitted the data very well (R2 = 0.89) showing a high stability, being able to generate very similar RMSEs during training and validation (RMSE(training) = 2.63; RMSE(validation) = 2.61). Data recorded on the card were automatically sent to a remote server allowing repeated field-data quality checks. This work provides a framework for the replication and upgrading of a customized low cost platform, consistent with the open source approach whereby sharing information on equipment design and software facilitates the adoption and continuous improvement of existing technologies.

  19. Numerical investigation of the impact of uncertainties in satellite rainfall estimation and land surface model parameters on simulation of soil moisture

    NASA Astrophysics Data System (ADS)

    Hossain, Faisal; Anagnostou, Emmanouil N.

    2005-12-01

    This study aims at evaluating the uncertainty in the prediction of soil moisture (1D, vertical column) from an offline land surface model (LSM) forced by hydro-meteorological and radiation data. We focus on two types of uncertainty: an input error due to satellite rainfall retrieval uncertainty, and, LSM soil-parametric error. The study is facilitated by in situ and remotely sensed data-driven (precipitation, radiation, soil moisture) simulation experiments comprising a LSM and stochastic models for error characterization. The parametric uncertainty is represented by the generalized likelihood uncertainty estimation (GLUE) technique, which models the parameter non-uniqueness against direct observations. Half-hourly infra-red (IR) sensor retrievals were used as satellite rainfall estimates. The IR rain retrieval uncertainty is characterized on the basis of a satellite rainfall error model (SREM). The combined uncertainty (i.e., SREM + GLUE) is compared with the partial assessment of uncertainty. It is found that precipitation (IR) error alone may explain moderate to low proportion of the soil moisture simulation uncertainty, depending on the level of model accuracy—50-60% for high model accuracy, and 20-30% for low model accuracy. Comparisons on the basis of two different sites also yielded an increase (50-100%) in soil moisture prediction uncertainty for the more vegetated site. This study exemplified the need for detailed investigations of the rainfall retrieval-modeling parameter error interaction within a comprehensive space-time stochastic framework for achieving optimal integration of satellite rain retrievals in land data assimilation systems.

  20. Improvement of growth of Eucalyptus globulus and soil biological parameters by amendment with sewage sludge and inoculation with arbuscular mycorrhizal and saprobe fungi.

    PubMed

    Arriagada, C; Sampedro, I; Garcia-Romera, I; Ocampo, J

    2009-08-15

    Sewage sludge is widely used as an organic soil amendment to improve soil fertility. We investigated the effects of sewage sludge (SS) application on certain biological parameters of Eucalyptus globulus Labill. The plant was either uninoculated or inoculated with saprobe fungi (Coriolopsis rigida and Trichoderma harzianum) or arbuscular mycorrhizal (AM) fungi (Glomus deserticola and Gigaspora rosea). Sewage sludge was applied to the surface of experimental plots at rates of 0, 2, 4, 6 and 8 g 100 g(-1) of soil. Inoculation with both AM and saprobe fungi in the presence of SS was essential for the promotion of plant growth. The AM, saprobe fungi and SS significantly increased dry shoot weight. The AM fungi induced a significant increase in Fluorescein diacetate (FDA) activity but did not increase beta-glucosidase activity. Addition of SS to AM-inoculated soil did not affect either FDA or alpha-glucosidase activities in plants from soil that was either uninoculated or inoculated with the saprobe fungi. SS increased beta-glucosidase activity when it was applied at 4 g 100 g(-1). SS negatively affected AM colonization as well as the mycelium SDH activity for both mycorrhizal fungi. SS increased Eucalyptus shoot biomass and enhanced its nutrient status. Inoculation of the soil with G. deserticola stimulated significant E. globulus growth and increases in shoot tissue content of N, P, K, Ca, Mg and Fe. Dual inoculation with G. deserticola and either of the saprobe fungi had positive effects on K, Ca, Mg and Fe contents. The application of 8 g 100 g(-1) of SS had no positive effects on plant nutrition. The experimental setup provided a suitable tool for evaluating SS in combination with saprobe and AM fungi as a biological fertiliser for its beneficial effects on E. globulus plant growth. PMID:19515400

  1. Optimal Land Use Management for Soil Erosion Control by Using an Interval-Parameter Fuzzy Two-Stage Stochastic Programming Approach

    NASA Astrophysics Data System (ADS)

    Han, Jing-Cheng; Huang, Guo-He; Zhang, Hua; Li, Zhong

    2013-09-01

    Soil erosion is one of the most serious environmental and public health problems, and such land degradation can be effectively mitigated through performing land use transitions across a watershed. Optimal land use management can thus provide a way to reduce soil erosion while achieving the maximum net benefit. However, optimized land use allocation schemes are not always successful since uncertainties pertaining to soil erosion control are not well presented. This study applied an interval-parameter fuzzy two-stage stochastic programming approach to generate optimal land use planning strategies for soil erosion control based on an inexact optimization framework, in which various uncertainties were reflected. The modeling approach can incorporate predefined soil erosion control policies, and address inherent system uncertainties expressed as discrete intervals, fuzzy sets, and probability distributions. The developed model was demonstrated through a case study in the Xiangxi River watershed, China's Three Gorges Reservoir region. Land use transformations were employed as decision variables, and based on these, the land use change dynamics were yielded for a 15-year planning horizon. Finally, the maximum net economic benefit with an interval value of [1.197, 6.311] × 109 was obtained as well as corresponding land use allocations in the three planning periods. Also, the resulting soil erosion amount was found to be decreased and controlled at a tolerable level over the watershed. Thus, results confirm that the developed model is a useful tool for implementing land use management as not only does it allow local decision makers to optimize land use allocation, but can also help to answer how to accomplish land use changes.

  2. Optimal land use management for soil erosion control by using an interval-parameter fuzzy two-stage stochastic programming approach.

    PubMed

    Han, Jing-Cheng; Huang, Guo-He; Zhang, Hua; Li, Zhong

    2013-09-01

    Soil erosion is one of the most serious environmental and public health problems, and such land degradation can be effectively mitigated through performing land use transitions across a watershed. Optimal land use management can thus provide a way to reduce soil erosion while achieving the maximum net benefit. However, optimized land use allocation schemes are not always successful since uncertainties pertaining to soil erosion control are not well presented. This study applied an interval-parameter fuzzy two-stage stochastic programming approach to generate optimal land use planning strategies for soil erosion control based on an inexact optimization framework, in which various uncertainties were reflected. The modeling approach can incorporate predefined soil erosion control policies, and address inherent system uncertainties expressed as discrete intervals, fuzzy sets, and probability distributions. The developed model was demonstrated through a case study in the Xiangxi River watershed, China's Three Gorges Reservoir region. Land use transformations were employed as decision variables, and based on these, the land use change dynamics were yielded for a 15-year planning horizon. Finally, the maximum net economic benefit with an interval value of [1.197, 6.311] × 10(9) $ was obtained as well as corresponding land use allocations in the three planning periods. Also, the resulting soil erosion amount was found to be decreased and controlled at a tolerable level over the watershed. Thus, results confirm that the developed model is a useful tool for implementing land use management as not only does it allow local decision makers to optimize land use allocation, but can also help to answer how to accomplish land use changes.

  3. Improvement of growth of Eucalyptus globulus and soil biological parameters by amendment with sewage sludge and inoculation with arbuscular mycorrhizal and saprobe fungi.

    PubMed

    Arriagada, C; Sampedro, I; Garcia-Romera, I; Ocampo, J

    2009-08-15

    Sewage sludge is widely used as an organic soil amendment to improve soil fertility. We investigated the effects of sewage sludge (SS) application on certain biological parameters of Eucalyptus globulus Labill. The plant was either uninoculated or inoculated with saprobe fungi (Coriolopsis rigida and Trichoderma harzianum) or arbuscular mycorrhizal (AM) fungi (Glomus deserticola and Gigaspora rosea). Sewage sludge was applied to the surface of experimental plots at rates of 0, 2, 4, 6 and 8 g 100 g(-1) of soil. Inoculation with both AM and saprobe fungi in the presence of SS was essential for the promotion of plant growth. The AM, saprobe fungi and SS significantly increased dry shoot weight. The AM fungi induced a significant increase in Fluorescein diacetate (FDA) activity but did not increase beta-glucosidase activity. Addition of SS to AM-inoculated soil did not affect either FDA or alpha-glucosidase activities in plants from soil that was either uninoculated or inoculated with the saprobe fungi. SS increased beta-glucosidase activity when it was applied at 4 g 100 g(-1). SS negatively affected AM colonization as well as the mycelium SDH activity for both mycorrhizal fungi. SS increased Eucalyptus shoot biomass and enhanced its nutrient status. Inoculation of the soil with G. deserticola stimulated significant E. globulus growth and increases in shoot tissue content of N, P, K, Ca, Mg and Fe. Dual inoculation with G. deserticola and either of the saprobe fungi had positive effects on K, Ca, Mg and Fe contents. The application of 8 g 100 g(-1) of SS had no positive effects on plant nutrition. The experimental setup provided a suitable tool for evaluating SS in combination with saprobe and AM fungi as a biological fertiliser for its beneficial effects on E. globulus plant growth.

  4. Site-specific analysis of radiological and physical parameters for cobbly soils at the Gunnison, Colorado, processing site

    SciTech Connect

    Not Available

    1993-10-01

    The remedial action at the Gunnison, Colorado, processing site is being performed under the Uranium Mill Tailings Radiation Control Act (UMTRCA) of 1978 [Public Law (PL) 95-6041]. Under UMTRCA, the US Environmental Protection Agency (EPA) is charged with the responsibility of developing appropriate and applicable standards for the cleanup of radiologically contaminated land and buildings at 24 designated sites, including the Gunnison, Colorado, inactive processing site. The remedial action at the processing site will be conducted to remove the tailings and contaminated materials to meet the EPA bulk soil cleanup standards for surface and subsurface soils. The site areas disturbed by remedial action excavation will be either contoured or backfilled with radiologically uncontaminated soil and contoured to restore the site. The final contours will produce a final surface grade that will create positive drainage from the site.

  5. Aboveground Epichloë coenophiala-Grass Associations Do Not Affect Belowground Fungal Symbionts or Associated Plant, Soil Parameters.

    PubMed

    Slaughter, Lindsey C; McCulley, Rebecca L

    2016-10-01

    Cool season grasses host multiple fungal symbionts, such as aboveground Epichloë endophytes and belowground arbuscular mycorrhizal fungi (AMF) and dark septate endophytes (DSEs). Asexual Epichloë endophytes can influence root colonization by AMF, but the type of interaction-whether antagonistic or beneficial-varies. In Schedonorus arundinaceus (tall fescue), Epichloë coenophiala can negatively affect AMF, which may impact soil properties and ecosystem function. Within field plots of S. arundinaceus that were either E. coenophiala-free (E-), infected with the common, mammal-toxic E. coenophiala strain (CTE+), or infected with one of two novel, non-toxic strains (AR542 NTE+ and AR584 NTE+), we hypothesized that (1) CTE+ would decrease AMF and DSE colonization rates and reduce soil extraradical AMF hyphae compared to E- or NTE+, and (2) this would lead to E- and NTE+ plots having greater water stable soil aggregates and C than CTE+. E. coenophiala presence and strain did not significantly alter AMF or DSE colonization, nor did it affect extraradical AMF hypha length, soil aggregates, or aggregate-associated C and N. Soil extraradical AMF hypha length negatively correlated with root AMF colonization. Our results contrast with previous demonstrations that E. coenophiala symbiosis inhibits belowground AMF communities. In our mesic, relatively nutrient-rich grassland, E. coenophiala symbiosis did not antagonize belowground symbionts, regardless of strain. Manipulating E. coenophiala strains within S. arundinaceus may not significantly alter AMF communities and nutrient cycling, yet we must further explore these relationships under different soils and environmental conditions given that symbiont interactions can be important in determining ecosystem response to global change.

  6. Aboveground Epichloë coenophiala-Grass Associations Do Not Affect Belowground Fungal Symbionts or Associated Plant, Soil Parameters.

    PubMed

    Slaughter, Lindsey C; McCulley, Rebecca L

    2016-10-01

    Cool season grasses host multiple fungal symbionts, such as aboveground Epichloë endophytes and belowground arbuscular mycorrhizal fungi (AMF) and dark septate endophytes (DSEs). Asexual Epichloë endophytes can influence root colonization by AMF, but the type of interaction-whether antagonistic or beneficial-varies. In Schedonorus arundinaceus (tall fescue), Epichloë coenophiala can negatively affect AMF, which may impact soil properties and ecosystem function. Within field plots of S. arundinaceus that were either E. coenophiala-free (E-), infected with the common, mammal-toxic E. coenophiala strain (CTE+), or infected with one of two novel, non-toxic strains (AR542 NTE+ and AR584 NTE+), we hypothesized that (1) CTE+ would decrease AMF and DSE colonization rates and reduce soil extraradical AMF hyphae compared to E- or NTE+, and (2) this would lead to E- and NTE+ plots having greater water stable soil aggregates and C than CTE+. E. coenophiala presence and strain did not significantly alter AMF or DSE colonization, nor did it affect extraradical AMF hypha length, soil aggregates, or aggregate-associated C and N. Soil extraradical AMF hypha length negatively correlated with root AMF colonization. Our results contrast with previous demonstrations that E. coenophiala symbiosis inhibits belowground AMF communities. In our mesic, relatively nutrient-rich grassland, E. coenophiala symbiosis did not antagonize belowground symbionts, regardless of strain. Manipulating E. coenophiala strains within S. arundinaceus may not significantly alter AMF communities and nutrient cycling, yet we must further explore these relationships under different soils and environmental conditions given that symbiont interactions can be important in determining ecosystem response to global change. PMID:27502203

  7. Differences in water balance for hydrological response units defined from mobile measurements of soil and crop parameters

    NASA Astrophysics Data System (ADS)

    Vasquez, Vicente; Thomsen, Anton; Schelde, Kirsten; Knadel, Maria

    2014-05-01

    Variability in vegetation indices like the ratio vegetation index (RVI) and leaf area index (LAI) for a uniformly managed agricultural field can be associated with differences in plant available water and thus, differences in evapotranspiration (ET) and deep percolation (D). This variability has important implications for field scale water balance and water and fertilizer use efficiencies of the vegetation. Characterizations of the water balance often do not account for field scale heterogeneity arising from the spatial variability of soils and vegetation. In this study we evaluated differences in modelled ET and D from six hydrological response units (HRU) defined for a 25 ha sandy soil agricultural field in Western Denmark. The HRUs were identified by clustering a high resolution soil and vegetation sensory data. Crop development and soil water content were monitored during one growing season for each HRU and a soil water balance model applied to infer ET and D. It was shown that the easily measured RVI could be used to estimate LAI by linear regression with local measurements for each HRU. The local RVI to LAI regression was further validated by measurements made on the entire field with the MobilLas mobile canopy sensor. Differences in modelled ET for the growing season ranged from 10-35 mm between HRUs and were attributed to differences in water content at field capacity (FC) and maximum LAI. Differences in modelled D ranged from 5-25 mm and were also associated with differences in FC attributed to variation in the silt and soil carbon contents of HRUs. In summary, the investigated HRUs revealed differences in ET and D supporting the use of this approach to understand the field scale variation of the water balance and possibly optimize water and fertilizer use efficiency.

  8. Influence of variable topsoil replacement depths on soil chemical parameters within a coal mine in northeastern Wyoming, USA

    SciTech Connect

    Schladweiler, B.K.; Vance, G.F.; Legg, D.E.; Munn, L.C.; Haroian, R.

    2004-10-15

    Uniform topsoil replacement depths on coal mine reclaimed areas have been mandated by USA federal and state regulations; however, soils of the premine landscape are not naturally uniform in depth and vary in physical, chemical, and biological characteristics. In addition, uniform topsoil depths may actually hinder the development of diverse reclaimed plant communities. We studied the effect of varying topsoil replacement depth treatments (15, 30, and 56 cm) on soil and backfill pH, electrolytic conductivity (EC), and sodium adsorption ratio (SAR) within a reclaimed coal mine study area. Backfill material (also known as spoil) at this site did not possess levels of pH, EC, and SAR that were detrimental to plant growth. There was only a slight reduction in pH, EC, and SAR within the upper 15 cm depth in the reclaimed topsoil treatments with a general increase of EC and SAR in the lower portion of the replaced soil profile. Some downward movement of soluble salts within the reclaimed treatments was evident despite low precipitation. For examples, SAR in the 0-15 cm depth over all reclaimed treatments was lower in 2002 than 2000-2001, and the 0-30 cm portion of the reclaimed soil profile had reduced pH and EC, while the 30-60 cm portion had increased EC and SAR. It is anticipated that soil quality differences in terms of pH, EC, and SAR between topsoil depth treatments will be enhanced with time. Comparison of the reclaimed area to the native reference areas suggested numerous depth differences as a result of homogeneity of the replaced topsoil vs. undisturbed soil profiles.

  9. Soil experiment

    NASA Technical Reports Server (NTRS)

    Hutcheson, Linton; Butler, Todd; Smith, Mike; Cline, Charles; Scruggs, Steve; Zakhia, Nadim

    1987-01-01

    An experimental procedure was devised to investigate the effects of the lunar environment on the physical properties of simulated lunar soil. The test equipment and materials used consisted of a vacuum chamber, direct shear tester, static penetrometer, and fine grained basalt as the simulant. The vacuum chamber provides a medium for applying the environmental conditions to the soil experiment with the exception of gravity. The shear strength parameters are determined by the direct shear test. Strength parameters and the resistance of soil penetration by static loading will be investigated by the use of a static cone penetrometer. In order to conduct a soil experiment without going to the moon, a suitable lunar simulant must be selected. This simulant must resemble lunar soil in both composition and particle size. The soil that most resembles actual lunar soil is basalt. The soil parameters, as determined by the testing apparatus, will be used as design criteria for lunar soil engagement equipment.

  10. Modelling Hydrologic Fluxes on the Yangtze River Basin Using Satellite and Ground Data: Soil Calibration Parameters Using Satellite Land Surface Temperature

    NASA Astrophysics Data System (ADS)

    Corbari, Chiara; Mancini, Marco; Li, Jiren; Su, Bob

    2014-11-01

    A fully distributed hydrological model FEST-EWB will be calibrated assimilating satellite-based LST to calibrate soil and vegetation parameters in each pixel of the domain as a complementary method to the traditional calibration with local SM data. This is feasible because the model algorithm solves the system of energy and mass balances in terms of a representative equilibrium temperature (RET) that is the land surface temperature that closes the energy balance equation and so governs the fluxes of energy and mass over the basin domain. This equilibrium surface temperature, which is a critical model state variable, is comparable to LST as retrieved from operational remote sensing data (MODIS and AATSR) which is used for the calibration of soil and vegetation parameters. FEST-EWB is run in for the whole Yangtze River basin at spatial resolution of 0.05° and temporal resolution of 3 hours. Results are provided in terms of hourly evapotranspiration, soil moisture and land surface temperature maps for the period between 2003 to 2006. The effects on river discharge of the Three Gorges dam, the largest hydropower project in the world, will be evaluated as well as of the three large lakes (Poyang, Dongting and Taihu) which change considerably their area during the seasons (MERIS). Observed flow duration curves, for the four available river cross sections, will be evaluated and compared to FEST-EWB simulated flow duration curves as well as observed as simulated hydrographs.

  11. Effect of organic matter on the parameters of the selective sorption of cobalt and zinc by soils and their clay fractions

    NASA Astrophysics Data System (ADS)

    Anisimov, V. S.; Kochetkov, I. V.; Kruglov, S. V.; Aleksakhin, R. M.

    2011-06-01

    The sorption and ion-exchange behavior of Co(II) and Zn in the soil-equilibrium solution system was studied for different types and varieties of native soils and their clay fractions before and after mild oxidation with H2O2 to remove the organic carbon. The parameters of the ion-exchange adsorption and the selectivity coefficients of the (Co(II), Zn)/Ca ion exchange were determined using different models for describing the relationship between the dissolved and sorbed forms of the metals. These were the empirical Langmuir and Freundlich adsorption isotherms and the model of the ion-exchange adsorption based on the acting mass law. It was found that the soil organic matter played an important role in the selectivity of the ion-exchange adsorption of Co(II) and Zn by the soils and their clay fractions. This was confirmed by an abrupt decrease (to almost 1) of the selectivity coefficients of the Co2+/Ca2+ and Zn2+/Ca2+ exchange after the treatment of the clay fraction with hydrogen peroxide.

  12. Effect of Remediation Parameters on in-Air Ambient Dose Equivalent Rates When Remediating Open Sites with Radiocesium-contaminated Soil.

    PubMed

    Malins, Alex; Kurikami, Hiroshi; Kitamura, Akihiro; Machida, Masahiko

    2016-10-01

    Calculations are reported for ambient dose equivalent rates [H˙*(10)] at 1 m height above the ground surface before and after remediating radiocesium-contaminated soil at wide and open sites. The results establish how the change in H˙*(10) upon remediation depends on the initial depth distribution of radiocesium within the ground, on the size of the remediated area, and on the mass per unit area of remediated soil. The remediation strategies considered were topsoil removal (with and without recovering with a clean soil layer), interchanging a topsoil layer with a subsoil layer, and in situ mixing of the topsoil. The results show the ratio of the radiocesium components of H˙*(10) post-remediation relative to their initial values (residual dose factors). It is possible to use the residual dose factors to gauge absolute changes in H˙*(10) upon remediation. The dependency of the residual dose factors on the number of years elapsed after fallout deposition is analyzed when remediation parameters remain fixed and radiocesium undergoes typical downward migration within the soil column. PMID:27575348

  13. Effect of Remediation Parameters on in-Air Ambient Dose Equivalent Rates When Remediating Open Sites with Radiocesium-contaminated Soil.

    PubMed

    Malins, Alex; Kurikami, Hiroshi; Kitamura, Akihiro; Machida, Masahiko

    2016-10-01

    Calculations are reported for ambient dose equivalent rates [H˙*(10)] at 1 m height above the ground surface before and after remediating radiocesium-contaminated soil at wide and open sites. The results establish how the change in H˙*(10) upon remediation depends on the initial depth distribution of radiocesium within the ground, on the size of the remediated area, and on the mass per unit area of remediated soil. The remediation strategies considered were topsoil removal (with and without recovering with a clean soil layer), interchanging a topsoil layer with a subsoil layer, and in situ mixing of the topsoil. The results show the ratio of the radiocesium components of H˙*(10) post-remediation relative to their initial values (residual dose factors). It is possible to use the residual dose factors to gauge absolute changes in H˙*(10) upon remediation. The dependency of the residual dose factors on the number of years elapsed after fallout deposition is analyzed when remediation parameters remain fixed and radiocesium undergoes typical downward migration within the soil column.

  14. Combining forces--the use of Landsat TM satellite imagery, soil parameter information, and multiplex PCR to detect Coccidioides immitis growth sites in Kern County, California.

    PubMed

    Lauer, Antje; Talamantes, Jorge; Castañón Olivares, Laura Rosío; Medina, Luis Jaime; Baal, Joe Daryl Hugo; Casimiro, Kayla; Shroff, Natasha; Emery, Kirt W

    2014-01-01

    Coccidioidomycosis is a fungal disease acquired through the inhalation of spores of Coccidioides spp., which afflicts primarily humans and other mammals. It is endemic to areas in the southwestern United States, including the San Joaquin Valley portion of Kern County, California, our region of interest (ROI). Recently, incidence of coccidioidomycosis, also known as valley fever, has increased significantly, and several factors including climate change have been suggested as possible drivers for this observation. Up to date details about the ecological niche of C. immitis have escaped full characterization. In our project, we chose a three-step approach to investigate this niche: 1) We examined Landsat-5-Thematic-Mapper multispectral images of our ROI by using training pixels at a 750 m × 750 m section of Sharktooth Hill, a site confirmed to be a C. immitis growth site, to implement a Maximum Likelihood Classification scheme to map out the locations that could be suitable to support the growth of the pathogen; 2) We used the websoilsurvey database of the US Department of Agriculture to obtain soil parameter data; and 3) We investigated soil samples from 23 sites around Bakersfield, California using a multiplex Polymerase Chain Reaction (PCR) based method to detect the pathogen. Our results indicated that a combination of satellite imagery, soil type information, and multiplex PCR are powerful tools to predict and identify growth sites of C. immitis. This approach can be used as a basis for systematic sampling and investigation of soils to detect Coccidioides spp.

  15. Combining Forces - The Use of Landsat TM Satellite Imagery, Soil Parameter Information, and Multiplex PCR to Detect Coccidioides immitis Growth Sites in Kern County, California

    PubMed Central

    Lauer, Antje; Talamantes, Jorge; Castañón Olivares, Laura Rosío; Medina, Luis Jaime; Baal, Joe Daryl Hugo; Casimiro, Kayla; Shroff, Natasha; Emery, Kirt W.

    2014-01-01

    Coccidioidomycosis is a fungal disease acquired through the inhalation of spores of Coccidioides spp., which afflicts primarily humans and other mammals. It is endemic to areas in the southwestern United States, including the San Joaquin Valley portion of Kern County, California, our region of interest (ROI). Recently, incidence of coccidioidomycosis, also known as valley fever, has increased significantly, and several factors including climate change have been suggested as possible drivers for this observation. Up to date details about the ecological niche of C. immitis have escaped full characterization. In our project, we chose a three-step approach to investigate this niche: 1) We examined Landsat-5-Thematic-Mapper multispectral images of our ROI by using training pixels at a 750 m×750 m section of Sharktooth Hill, a site confirmed to be a C. immitis growth site, to implement a Maximum Likelihood Classification scheme to map out the locations that could be suitable to support the growth of the pathogen; 2) We used the websoilsurvey database of the US Department of Agriculture to obtain soil parameter data; and 3) We investigated soil samples from 23 sites around Bakersfield, California using a multiplex Polymerase Chain Reaction (PCR) based method to detect the pathogen. Our results indicated that a combination of satellite imagery, soil type information, and multiplex PCR are powerful tools to predict and identify growth sites of C. immitis. This approach can be used as a basis for systematic sampling and investigation of soils to detect Coccidioides spp. PMID:25380290

  16. Rock formation characterization for carbon dioxide geosequestration: 3D seismic amplitude and coherency anomalies, and seismic petrophysical facies classification, Wellington and Anson-Bates Fields, Kansas, USA

    NASA Astrophysics Data System (ADS)

    Ohl, Derek; Raef, Abdelmoneam

    2014-04-01

    Higher resolution rock formation characterization is of paramount priority, amid growing interest in injecting carbon dioxide, CO2, into subsurface rock formations of depeleting/depleted hydrocarbon reservoirs or saline aquifers in order to reduce emissions of greenhouse gases. In this paper, we present a case study for a Mississippian carbonate characterization integrating post-stack seismic attributes, well log porosities, and seismic petrophysical facies classification. We evaluated changes in petrophysical lithofacies and reveal structural facies-controls in the study area. Three cross-plot clusters in a plot of well log porosity and acoustic impedance corroborated a Neural Network petrophysical facies classification, which was based on training and validation utilizing three petrophysically-different wells and three volume seismic attributes, extracted from a time window including the wavelet of the reservoir-top reflection. Reworked lithofacies along small-throw faults has been revealed based on comparing coherency and seismic petrophysical facies. The main objective of this study is to put an emphasis on reservoir characterization that is both optimized for and subsequently benefiting from pilot tertiary CO2 carbon geosequestration in a depleting reservoir and also in the deeper saline aquifer of the Arbuckle Group, south central Kansas. The 3D seismic coherency attribute, we calculated from a window embracing the Mississippian top reflection event, indicated anomalous features that can be interpreted as a change in lithofacies or faulting effect. An Artificial Neural Network (ANN) lithofacies modeling has been used to better understand these subtle features, and also provide petrophysical classes, which will benefit flow-simulation modeling and/or time-lapse seismic monitoring feasibility analysis. This paper emphasizes the need of paying greater attention to small-scale features when embarking upon characterization of a reservoir or saline-aquifer for CO2

  17. Soil water content and evaporation determined by thermal parameters obtained from ground-based and remote measurements

    NASA Technical Reports Server (NTRS)

    Reginato, R.; Idso, S.; Vedder, J.; Jackson, R.; Blanchard, M.; Goettelman, R.

    1975-01-01

    A procedure is presented for calculating 24-hour totals of evaporation from wet and drying soils. Its application requires a knowledge of the daily solar radiation, the maximum and minimum, air temperatures, moist surface albedo, and maximum and minimum surface temperatures. Tests of the technique on a bare field of Avondale loam at Phoenix, Arizona showed it to be independent of season.

  18. Integration of Petrophysical Methods and 3D Printing Technology to Replicate Reservoir Pore Systems

    NASA Astrophysics Data System (ADS)

    Ishutov, S.; Hasiuk, F.; Gray, J.; Harding, C.

    2014-12-01

    Pore-scale imaging and modeling are becoming routine geoscience techniques of reservoir analysis and simulation in oil and gas industry. Three-dimensional printing may facilitate the transformation of pore-space imagery into rock models, which can be compared to traditional laboratory methods and literature data. Although current methodologies for rapid rock modeling and printing obscure many details of grain geometry, computed tomography data is one route to refine pore networks and experimentally test hypotheses related to rock properties, such as porosity and permeability. This study uses three-dimensional printing as a novel way of interacting with x-ray computed tomography data from reservoir core plugs based on digital modeling of pore systems in coarse-grained sandstones and limestones. The advantages of using artificial rocks as a proxy are to better understand the contributions of pore system characteristics at various scales to petrophysical properties in oil and gas reservoirs. Pore radii of reservoir sandstones used in this study range from 1 to 100s of microns, whereas the pore radii for limestones vary from 0.01 to 10s of microns. The resolution of computed tomography imaging is ~10 microns; the resolution of 3D digital printing used in the study varies from 2.5 to 300 microns. For this technology to be useful, loss of pore network information must be minimized in the course of data acquisition, modeling, and production as well as verified against core-scale measurements. The ultimate goal of this study is to develop a reservoir rock "photocopier" that couples 3D scanning and modeling with 3D printing to reproduce a) petrophyscially accurate copies of reservoir pore systems and b) digitally modified pore systems for testing hypotheses about reservoir flow. By allowing us to build porous media with known properties (porosity, permeability, surface area), technology will also advance our understanding of the tools used to measure these quantities (e

  19. Determination of Physico-chemical Parameters for Prediction of MSW Leachate Transport through Vadose Zone by Breakthrough Curve in a Realistic Undisturbed Soil Column.

    PubMed

    Pal, Shukla; Gupta, S K; Sreekrishnan, T R; Maitra, S S

    2014-04-01

    The studies were carried out to find out transport parameters to predict leachate transport and contaminant plume profile underneath a municipal solid waste(MSW) dump. For this, both theoretical and practical avenues were explored. Batch experiments with disturbed soil were carried out with a tracer dye Brilliant Blue FCF to obtain the adsorption isotherm of the tracer. Column experiments with undisturbed realistic soil column were carried out to determine physico-chemical transport parameters using the tracer dye. MSW leachate transport were simulated and sensitivity analysis for MSW leachate transport was carried out for different Darcy velocity for pulse input.For determination of mass-transfer coefficient between the immobilized and mobilized water phase, we usedthe concept of number of transfer units (NTUs) and height of transfer units (HTUs) frequently used by Chemical Engineers. The obtained value of mass transfer coefficient calculated by this method was in excellent agreement with the value obtained from inverse calculation of parameter values by a standard software package (CXTFIT). PMID:26563064

  20. Effect of simultaneous state-parameter estimation and forcing uncertainties on root-zone soil moisture for dynamic vegetation using EnKF

    NASA Astrophysics Data System (ADS)

    Monsivais-Huertero, Alejandro; Graham, Wendy D.; Judge, Jasmeet; Agrawal, Divya

    2010-04-01

    In this study, an EnKF-based assimilation algorithm was implemented to estimate root-zone soil moisture (RZSM) using the coupled LSP-DSSAT model during a growing season of corn. Experiments using both synthetic and field observations were conducted to understand effects of simultaneous state-parameter estimation, spatial and temporal update frequency, and forcing uncertainties on RZSM estimates. Estimating the state-parameters simultaneously with every 3-day assimilation of volumetric soil moisture (VSM) observations at 5 depths lowered the average standard deviation (ASD) and the root mean square error (RMSE) for RZSM by approximately 1.77% VSM (78%) and 2.18% VSM (93%), respectively, compared to the open-loop ASD where as estimating only states lowered the ASD by approximately 1.26% VSM (56%) and the RMSE by 1.66% VSM (71%). The synthetic case obtained RZSM estimates closer to the observations than the MicroWEX-2 case, particularly after precipitation/irrigation events. The differences in EnKF performance between MicroWEX-2 and synthetic observations may indicate other sources of errors in addition to those in parameters and forcings, such as errors in model biophysics.

  1. Response of stress indicators and growth parameters of Tibouchina pulchra Cogn. exposed to air and soil pollution near the industrial complex of Cubatão, Brazil.

    PubMed

    Klumpp, G; Furlan, C M; Domingos, M; Klumpp, A

    2000-01-31

    The present study was performed in the vicinity of the industrial complex of Cubatão, São Paulo, Brazil, in order to evaluate the response of 'manaca da serra' Tibouchina pulchra Cogn. (Melastomataceae), a common species of secondary Atlantic Rain Forest vegetation, to the impact of complex air pollution. Emphasis was given to changes of biochemical parameters such as ascorbic acid concentration, peroxidase activity, contents of water-soluble thiols, pH of leaf extract and buffering capacity. These plant factors are often used as early indicators of air pollution stress. Field experiments included sampling of leaves from mature trees in areas with different air pollution load (passive monitoring), exposure of saplings cultivated in uniform soil at these areas (active monitoring) and a study on the combined effects of contaminated soil and air pollution. In general, metabolic response of saplings was more accentuated than that of mature trees. Leaf extract pH and buffering capacity showed no or only small alterations in plants exposed to industrial emissions. In contrast, air pollution resulted in a distinct decrease in ascorbic acid contents and an increase in peroxidase activity and thiol concentrations in leaves. Cultivation of saplings in soil types from contaminated regions frequently caused the same modifications or enhanced the effects produced by air pollution. Growth analysis of exposed saplings demonstrated that a change of the relationship between above-ground and below-ground plant parts was the most obvious effect of air pollution and soil contamination. The experiments showed that even T. pulchra, a species considered resistant to air pollution, suffers metabolic disturbances by the present ambient air and soil quality. Although biochemical and physiological alterations were not related to a certain air pollution type, they could be used to estimate the overall pollution load and to map zones with different air quality.

  2. An integrated petrophysical-geophysical approach for the characterization of a potential caprock-reservoir system for CO2 storage.

    NASA Astrophysics Data System (ADS)

    Fais, Silvana; Ligas, Paola; Cuccuru, Francesco; Casula, Giuseppe; Giovanna Bianchi, Maria; Maggio, Enrico; Plaisant, Alberto; Pettinau, Alberto

    2016-04-01

    The selection of a CO2 geologic storage site requires the choice of a study site suitable for the characterization in order to create a robust experimental database especially regarding the spatial petrophysical heterogeneities and elasto-mechanical properties of the rocks that make up a potential caprock-reservoir system. In our study the petrophysical and elasto-mechanical characterization began in a previously well drilled area in the northern part of the Sulcis coal basin (Nuraxi Figus area - SW Sardinia - Italy) where crucial geologic data were recovered from high-quality samples from stratigraphic wells and from mining galleries. The basin represents one of the most important Italian carbon reserves characterized by a great mining potential. In the study area, the Middle Eocene - Lower Oligocene Cixerri Fm. made up of terrigeneous continental rocks and the Upper Thanetian - Lower Ypresian Miliolitico Carbonate Complex in the Sulcis coal basin have been identified respectively as potential caprock and reservoir for CO2 storage. Petrophysical and geophysical investigations were carried out by a great number of laboratory tests on the core samples and in situ measurements on a mining gallery in order to characterize the potential caprock-reservoir system and to substantially reduce geologic uncertainty in the storage site characterization and in the geological and numerical modelling for the evaluation of CO2 storage capacity. In order to better define the spatial distribution of the petrophysical heterogeneity, the seismic responses from the caprock-reservoir system formations were also analysed and correlated with the petrophysical and elasto-mechanical properties In a second step of this work, we also analysed the tectonic stability of the study area by the integrated application of remote-sensing monitoring spatial geodetic techniques. In particular, the global positioning system (GPS) and interferometric synthetic aperture radar (inSAR) were considered

  3. Stochastic analysis and prioritization of the influence of parameter uncertainty on the predicted pressure profile in heterogeneous, unsaturated soils.

    PubMed

    Paleologos, Evan K; Avanidou, T; Mylopoulos, N

    2006-08-10

    This article utilizes a Monte Carlo stochastic framework to investigate the influence on the mean and variance of the predicted mean pressure head profile of statistical assumptions regarding the parameters that enter the mathematical description of the problem of infiltration in unsaturated, heterogeneous layers. The parameters are treated as random functions with an exponential auto-covariance function expressing their spatial continuity. Four different truncated distributions are taken to describe the parameters according to field observations and various phases of site characterization campaigns. The exponential distribution is seen to produce the largest (in absolute value) mean and variance in the pressure head profile. For all distributions the variance in pressure head increases with increasing mean pressure. A second topic of this article is to investigate, the relative importance of each parameter, in terms of the mean and the variance of the predicted pressure. For uniformly or triangularly distributed parameters the saturated hydraulic conductivity appears to dominate the mean-behavior and the uncertainty in the system's solution. For lognormally or exponentially distributed parameters another parameter, the van Genuchten pore-size distribution index, is the dominant factor. PMID:16386368

  4. Light intensity and production parameters of phytocenoses cultivated on soil-like substrate under controlled [correction of controled] environment conditions.

    PubMed

    Tikhomirov, A A; Ushakova, S A; Gribovskaya, I A; Tirranen, L S; Manukovsky, N S; Zolotukhin, I G; Karnachuk, R A; Gros, J B; Lasseur, Ch

    2003-01-01

    To increase the degree of closure of biological life support systems of a new generation, we used vermicomposting to involve inedible phytomass in the intra-system mass exchange. The resulting product was a soil-like substrate, which was quite suitable for growing plants (Manukovsky et al. 1996, 1997). However, the soil like substrate can be regarded as a candidate for inclusion in a system only after a comprehensive examination of its physical, chemical, and other characteristics. An important criterion is the ability of the soil-like substrate to supply the necessary mineral elements to the photosynthesizing component under the chosen cultivation conditions. Thus, the purpose of this work was to study the feasibility of enhancing the production activity of wheat and radish crops by varying the intensity of photosynthetically active radiation, without decreasing the harvest index. The increase of light intensity from 920 to 1150 micromoles m-2 s-1 decreased the intensity of apparent photosynthesis of the wheat crops and slightly increased the apparent photosynthesis of the radish crops The maximum total and grain productivity (kg/m2) of the wheat crops was attained at the irradiance of 920 micromoles m-2 s-1. Light intensity of 1150 micromoles m-2 s-1 decreased the productivity of wheat plants and had no significant effect on the productivity of the radish crops (kg/m2) as compared to 920 micromoles m-2 s-1. The qualitative and quantitative composition of microflora of the watering solution and substrate was determined by the condition of plants, developmental phase and light intensity. By the end of wheat growth under 1150 micromoles m-2 s-1 the numbers of bacteria of the coliform family and phytopathogenic bacteria in the watering solution and substrate were an order of magnitude larger than under other illumination conditions. The obtained data suggest that the cultivation of plants in a life support system on soil-like substrate from composts has a number of

  5. Selected kinetic parameters of soil microbial respiration in the A horizon of differently managed mountain forests and meadows of Moravian-Silesian Beskids Mts.

    NASA Astrophysics Data System (ADS)

    Vranová, V.; Formánek, P.; Rejšek, K.; Kisza, L.

    2009-03-01

    The aim of this study was to find out the effect of intensity of thinning (FD-dense stand = 2044 trees/ha; FS-open stand = 1652 trees/ha) performed in young forest stands (99% spruce, 1% fir) in Moravian-Silesian Beskids Mts. (908 m a.s.l.; 49°30'10″ N, 18°32'20″ E) on V DS (C mineralization rate immediately after drying and re-wetting of soil), V BR (basal soil respiration at 60% w/w soil water content measured 5th day after rewetting of dry soil), V MAX (maximum respiration rate after glucose addition measured from 6th day after rewetting of dry soil), V DS/ V MAX (heterotrophic respiratory potential) and ACDS/ACBR (the potential flush of biologically available C) in Ae horizon of Haplic and Entic Podzols. The ACDS/ACBR was calculated from three 24-hour respirations of 7-day incubation according to the equation ACDS/ACBR= V DS V MAX/(2 V BR( V MAX- V DS)). The aim of the work was also to find the effect of circa 11-year abandonment of a mountain meadow in the locality (825-860 m a.s.l.; 49°30'17″ N, 18°32'28″ E) on the same parameters in Ah horizon of Gleyic Luvisol. The studied parameters were measured in the course of the vegetation season 2004 (May-September) at 30-day intervals. The higher intensity of thinning caused alternately higher or lower or very similar values of V DS, V BR, V MAX, V DS/ V MAX and ACDS/ACBR in the course of the season. The abandonment of the meadow increased V DS, V BR, V MAX throughout the whole experiment. V DS/ V MAX increased due to the abandonment except for the last sampling in September. Alternately higher or lower or very similar values of ACDS/ACBR in course of the season appeared on abandoned or moderately mown meadows. The lower intensity of thinning or abandonment of the meadow were connected with increasing number of significant ( P < 0.05) correlations between the studied properties.

  6. Structural and Petrophysical Characterization of Fault Zones in Shales: Example from the Tournemire Url (sw, France)

    NASA Astrophysics Data System (ADS)

    DICK, P.; Du Peloux de Saint Romain, A.; Moreno, E.; Homberg, C.; Renel, F.; Dauzères, A.; Wittebroodt, C.; Matray, J.

    2013-12-01

    The Tournemire Underground Research Laboratory (URL) operated by IRSN (French Institute for Radiological Protection and Nuclear Safety) is located on the western border of the Mesozoic sedimentary Causses Basin (SW France). The URL crosses a thick Toarcian shale formation (≈250 m) and is interbedded between two aquiferous limestone formations. In addition to the 250 m thick overlying limestones, the geotechnical and hydrogeological characteristics of this site exhibit similarities with those measured by the French National Agency for Radioactive Waste Management (Andra) in the Callovo-Oxfordian formation of Bure (Meuse/Haute Marne, France). The Tournemire site is marked by numerous minor shear bands that affect not only the shale formation but also the over- and underlying limestone units. Since analogous discontinuities in an underground deep geological repository could act as a preferential pathway for radionuclide migration, the Tournemire site appears as an ideal location to understand the internal and permeability structures of such clay-based faults. In this study, we investigate the structural and petrophysical variations observed in a 10-15 m thick, subvertical, strike-slip shear band. For this, eight fully cored and logged horizontal boreholes were drilled normal to the fault's direction. The internal architecture and permeability of the fault was revealed through a combination of different tools (AMS, SEM, XRD and helium pycnometer) used on samples, as well as optical, induction and neutron porosity logging used in boreholes. The analysis of core samples from the different boreholes indicates that the studied fault zone is divided into a fault core (gouge), surrounded by a damaged zone (e.g., kinematically related fracture sets, small faults, and veins). Porosity and hydraulic conductivity values are low in the undisturbed shale (respectively, 9% and 10-14 m.s-1) and increase progressively towards the fault core (respectively, 15-20% and 5.10-12 m.s-1

  7. Petrophysical Properties of Cody, Mowry, Shell Creek, and Thermopolis Shales, Bighorn Basin, Wyoming

    NASA Astrophysics Data System (ADS)

    Nelson, P. H.

    2013-12-01

    The petrophysical properties of four shale formations are documented from well-log responses in 23 wells in the Bighorn Basin in Wyoming. Depths of the examined shales range from 4,771 to 20,594 ft. The four formations are the Thermopolis Shale (T), the Shell Creek Shale (SC), the Mowry Shale (M), and the lower part of the Cody Shale (C), all of Cretaceous age. These four shales lie within a 4,000-ft, moderately overpressured, gas-rich vertical interval in which the sonic velocity of most rocks is less than that of an interpolated trendline representing a normal increase of velocity with depth. Sonic velocity, resistivity, neutron, caliper, and gamma-ray values were determined from well logs at discrete intervals in each of the four shales in 23 wells. Sonic velocity in all four shales increases with depth to a present-day depth of about 10,000 ft; below this depth, sonic velocity remains relatively unchanged. Velocity (V), resistivity (R), neutron porosity (N), and hole diameter (D) in the four shales vary such that: VM > VC > VSC > VT, RM > RC > RSC > RT, NT > NSC ≈ NC > NM, and DT > DC ≈ DSC > DM. These orderings can be partially understood on the basis of rock compositions. The Mowry Shale is highly siliceous and by inference comparatively low in clay content, resulting in high sonic velocity, high resistivity, low neutron porosity, and minimal borehole enlargement. The Thermopolis Shale, by contrast, is a black fissile shale with very little silt--its high clay content causes low velocity, low resistivity, high neutron response, and results in the greatest borehole enlargement. The properties of the Shell Creek and lower Cody Shales are intermediate to the Mowry and Thermopolis Shales. The sonic velocities of all four shales are less than that of an interpolated trendline that is tied to velocities in shales above and below the interval of moderate overpressure. The reduction in velocity varies among the four shales, such that the amount of offset (O) from

  8. Population dynamics of earthworms in relation to soil physico-chemical parameters in agroforestry systems of Mizoram, India.

    PubMed

    Lalthanzara, H; Ramanujam, S N; Jha, L K

    2011-09-01

    Earthworm population dynamics was studied in two agroforestry systems in the tropical hilly terrain of Mizoram, north-east India, over a period of 24 months, from July 2002 to June 2004. Two sites of agroforestry situated at Sakawrtuichhun (SKT) and Pachhunga University College (PUC) campus, Aizawl, having pineapple as the main crop, were selected for detail studies on population dynamics. Five of the total twelve species of earthworm reported from the state were recorded in the study sites. The density of earthworm ranged from 6 to 243 ind.m(-2) and biomass from 3.2 - 677.64 g.m(-2) in SKT. Comparatively the density and biomass in PUC, which is at relatively higher altitude were lowerwith a range of 0 to 176 ind.m(-2) and biomass from 0 - 391.36 g.m(-2) respectively. Population dynamics of earthworm was significantly correlated with rainfall and physical characters of the soil. Earthworm biomass was significantly affected by rainfall and moisture content of the soil. The influence of chemical factors was relatively less.

  9. On the air-filled effective porosity parameter of Rogers and Nielson's (1991) bulk radon diffusion coefficient in unsaturated soils.

    PubMed

    Saâdi, Zakaria

    2014-05-01

    The radon exhalation rate at the earth's surface from soil or rock with radium as its source is the main mechanism behind the radon activity concentrations observed in both indoor and outdoor environments. During the last two decades, many subsurface radon transport models have used Rogers and Nielson's formula for modeling the unsaturated soil bulk radon diffusion coefficient. This formula uses an "air-filled effective porosity" to account for radon adsorption and radon dissolution in the groundwater. This formula is reviewed here, and its hypotheses are examined for accuracy in dealing with subsurface radon transport problems. The author shows its limitations by comparing one dimensional steady-state analytical solutions of the two-phase (air/water) transport equation (Fick's law) with Rogers and Nielson's formula. For radon diffusion-dominated transport, the calculated Rogers and Nielson's radon exhalation rate is shown to be unrealistic as it is independent of the values of the radon adsorption and groundwater dissolution coefficients. For convective and diffusive transport, radon exhalation rates calculated using Fick's law and this formula agree only for high values of gas-phase velocity and groundwater saturation. However, these conditions are not usually met in most shallow subsurface environments where radon migration takes place under low gas phase velocities and low water saturation.

  10. On the air-filled effective porosity parameter of Rogers and Nielson's (1991) bulk radon diffusion coefficient in unsaturated soils.

    PubMed

    Saâdi, Zakaria

    2014-05-01

    The radon exhalation rate at the earth's surface from soil or rock with radium as its source is the main mechanism behind the radon activity concentrations observed in both indoor and outdoor environments. During the last two decades, many subsurface radon transport models have used Rogers and Nielson's formula for modeling the unsaturated soil bulk radon diffusion coefficient. This formula uses an "air-filled effective porosity" to account for radon adsorption and radon dissolution in the groundwater. This formula is reviewed here, and its hypotheses are examined for accuracy in dealing with subsurface radon transport problems. The author shows its limitations by comparing one dimensional steady-state analytical solutions of the two-phase (air/water) transport equation (Fick's law) with Rogers and Nielson's formula. For radon diffusion-dominated transport, the calculated Rogers and Nielson's radon exhalation rate is shown to be unrealistic as it is independent of the values of the radon adsorption and groundwater dissolution coefficients. For convective and diffusive transport, radon exhalation rates calculated using Fick's law and this formula agree only for high values of gas-phase velocity and groundwater saturation. However, these conditions are not usually met in most shallow subsurface environments where radon migration takes place under low gas phase velocities and low water saturation. PMID:24670909

  11. Parallel factor analysis of excitation-emission matrix fluorescence spectra of water soluble soil organic matter as basis for the determination of conditional metal binding parameters.

    PubMed

    Ohno, Tsutomu; Amirbahman, Aria; Bro, Rasmus

    2008-01-01

    Organic matter-metal complexes in soil solution and aquatic systems are involved in important environmental and ecological processes such as plant nutrient availability and the solubilization and transport of metals. Our work presented here extends the use of fluorescence spectrometry for determining conditional stability constants for such complexes. We combine the use of excitation-emission matrix (EEM) fluorescence spectrometry and parallel factor analysis (PARAFAC) to determine the stability constants of the chemically meaningful components modeled by PARAFAC. Water-soluble organic matter (WSOM) from O-horizon soils of deciduous and coniferous forest stands were extracted and titrated at pH = 4.7 with iron(lll) (Fe) and aluminum (Al) which are important metals in acid soil systems. The EEM spectra were then recorded and PARAFAC analysis showed that the WSOM contained three humic-substance-like components. Fe titration led to fluorescence quenching of the three components, while Al titration enhanced fluorescence for two components and quenched one of the components. The average Ryan-Weber stability constants at pH 4.7 ranged from log K of 4.28 to 4.91 for Fe and 4.84 to 5.96 for Al. The conditional stability constants were similar for Fe binding for deciduous and coniferous stand-derived WSOM, while they were stronger for Al binding with coniferous stand-derived WSOM. This difference in binding strengths for Al may affect the chemical behavior of Al in soil and aquatic systems. Determining the individual binding parameters of organic matter components with metals represents a significant advance over current approaches that utilize fluorescence quenching at a single excitation-emission wavelength pair to characterize organic matter-metal interactions.

  12. Light intensity and production parameters of phytocenoses cultivated on soil-like substrate under controled environment conditions

    NASA Astrophysics Data System (ADS)

    Tikhomirov, A. A.; Ushakova, S. A.; Gribovskaya, I. A.; Tirranen, L. S.; Manukovsky, N. S.; Zolotukhin, I. G.; Karnachuk, R. A.; Gros, J.-B.; Lasseur, Ch.

    To increase the degree of closure of biological life support systems of a new generation, we used vermicomposting to involve inedible phytomass in the intra-system mass exchange. The resulting product was a soil-like substrate, which was quite suitable for growing plants (Manukovsky et al. 1996, 1997). However, the soil like substrate can be regarded as a candidate for inclusion in a system only after a comprehensive examination of its physical, chemical, and other characteristics. An important criterion is the ability of the soil-like substrate to supply the necessary mineral elements to the photosynthesizing component under the chosen cultivation conditions. Thus, the purpose of this work was to study the feasibility of enhancing the production activity of wheat and radish crops by varying the intensity of photosynthetically active radiation, without decreasing the harvest index. The increase of light intensity from 920 to 1150 μmol·m -2·s -1 decreased the intensity of apparent photosynthesis of the wheat crops and slightly increased the apparent photosynthesis of the radish crops The maximum total and grain productivity (kg/m -2) of the wheat crops was attained at the irradiance of 920 μmol·m -2·s -1. Light intensity of 1150 μmol·m -2·s -1 decreased the productivity of wheat plants and had no significant effect on the productivity of the radish crops (kg/m 2) as compared to 920 μmol·m -2·s -1. The qualitative and quantitative composition of microflora of the watering solution and substrate was determined by the condition of plants, developmental phase and light intensity. By the end of wheat growth under 1150 μmol·m -2·s -1 the numbers of bacteria of the coliform family and phytopathogenic bacteria in the watering solution and substrate were an order of magnitude larger than under other illumination conditions. The obtained data suggest that the cultivation of plants in a life support system on soil-like substrate from composts has a number of

  13. Estimation and upscaling of dual-permeability model parameters for the transport of E. coli D21g in soils with preferential flow.

    PubMed

    Wang, Yusong; Bradford, Scott A; Šimůnek, Jiří

    2014-04-01

    Dual-permeability models are increasingly used to quantify the transport of solutes and microorganisms in soils with preferential flow. An ability to accurately determine the model parameters and their variation with preferential pathway characteristics is crucial for predicting the transport of microorganisms in the field. The dual-permeability model with optimized parameters was able to accurately describe the transport of E. coli D21g in columns with artificial macropores of different configurations and lengths at two ionic strength levels (1 and 20mM NaCl). Correlations between the model parameters and the structural geometry of the preferential flow path were subsequently investigated. Decreasing the macropore length produced a decrease in the apparent saturated hydraulic conductivity of the macropore domain and an increase in the mass transfer between the macropore and matrix domains. The mass transfer coefficient was also found to be dependent on the configuration of the preferential flow pathway. A linear superposition approach was used to estimate field-scale preferential transport behavior for hypothetical fields with different amounts and configurations of macropores. Upscaling procedures were numerically investigated to predict this field-scale transport behavior from column-scale parameters. The upscaling method provided a satisfactory prediction of the field results under the tested scenarios. This information will be useful in assessing the risks of microbial transport due to preferential flow. PMID:24589387

  14. Estimation and upscaling of dual-permeability model parameters for the transport of E. coli D21g in soils with preferential flow.

    PubMed

    Wang, Yusong; Bradford, Scott A; Šimůnek, Jiří

    2014-04-01

    Dual-permeability models are increasingly used to quantify the transport of solutes and microorganisms in soils with preferential flow. An ability to accurately determine the model parameters and their variation with preferential pathway characteristics is crucial for predicting the transport of microorganisms in the field. The dual-permeability model with optimized parameters was able to accurately describe the transport of E. coli D21g in columns with artificial macropores of different configurations and lengths at two ionic strength levels (1 and 20mM NaCl). Correlations between the model parameters and the structural geometry of the preferential flow path were subsequently investigated. Decreasing the macropore length produced a decrease in the apparent saturated hydraulic conductivity of the macropore domain and an increase in the mass transfer between the macropore and matrix domains. The mass transfer coefficient was also found to be dependent on the configuration of the preferential flow pathway. A linear superposition approach was used to estimate field-scale preferential transport behavior for hypothetical fields with different amounts and configurations of macropores. Upscaling procedures were numerically investigated to predict this field-scale transport behavior from column-scale parameters. The upscaling method provided a satisfactory prediction of the field results under the tested scenarios. This information will be useful in assessing the risks of microbial transport due to preferential flow.

  15. Petrophysical laboratory invertigations of carbon dioxide storage in a subsurface saline aquifer in Ketzin/Germany within the scope of CO2SINK

    NASA Astrophysics Data System (ADS)

    Zemke, K.; Kummmerow, J.; Wandrey, M.; Co2SINK Group

    2009-04-01

    conditions over a period of several months. Before and after the CO2 exposure experiment cyclic measurements of physical properties were carried out on these cores in a mechanical testing system. After experimental runs of up to 3 months no significant changes in flow and petrophysical data were observed. [For the microbilogical studies see Wandrey et al., this volume.] To study the impact of fluid-rock interactions on petrophysical parameters, porosity and pore radii distribution have been investigated before and after the experiment by NMR relaxation and mercury-injection. NMR measurements on rock core plugs saturated with brine may return valuable information on the porous structure of the rock core. The distribution of NMR-T2 values (CPMG) reflects the pore sizes within the rock core. NMR pore size is a derivative of the ratio pore surface/volume. The mercury injection pore size is an area-equivalent diameter of the throats connecting the pore system. Most of the tested samples show in the NMR measurements a slightly increasing porosity and a higher part of large pores. The mercury measurements and thin- section for microstructural characterisation after the CO2 exposure will be done at a later date.

  16. Foliated vs. dilatant fault rocks in deeply buried arkosic turbidites: characterisation of their distinct petrophysical properties. The case of the Gres d'Annot, French Alps

    NASA Astrophysics Data System (ADS)

    Cavailhes, Thibault; Labaume, Pierre; Sizun, Jean-Pierre; Soliva, Roger; Gout, Claude; Chauvet, Alain; Buatier, Martine; Potdevin, Jean-Luc; Charpentier, Delphine; Trave, Anna

    2013-04-01

    Fault zones are major discontinuities in sedimentary basins. Understanding their role on fluid migrations is an essential issue to (i) characterise the mechanisms and kinematics of deformation and (ii) to determine the parameters which control the distribution of energetic or mineral resources. This work applies to faulting under a temperature range of 200-250°C, corresponding to that of deeply buried reservoirs as well as potentially seismogenic fault zones. The studied faults are normal faults affecting the "Grès d'Annot" Formation, a Priabonian-Rupelian siliclastic turbidite succession of the Alpine foreland basin. They are located in two distinct areas: the Moutière-Restefond area in the eastern part of the basin and the Estrop area in the western part. Vitrinite reflectance outside fault zones indicates maximal temperatures of 240-260°C at Moutière-Restefond and 170-200°C at Estrop, i.e. burial depths around 8 km and 6 km, respectively, assuming a mean geothermal gradient of 30°C/km. Burial was due to underthrusting below the Embrunais-Ubaye Alpine nappes, the difference in burial between the two areas traducing the westward taper of the nappes front. The studied faults affect alternating arkosic sandstone beds and pelite layers with offsets from centimeters to decameters. Two types of core zones are recognized: (1) the foliated core zones of the Moutière-Restefond area, where deformation dominated by pressure solution and synkinematic phyllosilicate neoformation resulted in a foliated fabric, and (2) the core zones of the Estrop area, characterized by dilatant quartz-mineralized veins and breccia. Fault and host rock petrophysical properties were measured on drill plugs, using the water porosity technique and nitrogen permeability technique under 2 Mpa of confining pressure. In the Moutière-Restefond fault zones, plug axes were oriented in three orthogonal directions corresponding to the main deformation axes (X, Y, Z) of the foliated arkose to

  17. Variations of the petrophysical properties of rocks with increasing hydrocarbons content and their implications at larger scale: insights from the Majella reservoir (Italy)

    NASA Astrophysics Data System (ADS)

    Trippetta, Fabio; Ruggieri, Roberta; Lipparini, Lorenzo

    2016-04-01

    Crustal processes such as deformations or faulting are strictly related to the petrophysical properties of involved rocks. These properties depend on mineral composition, fabric, pores and any secondary features such as cracks or infilling material that may have been introduced during the whole diagenetic and tectonic history of the rock. In this work we investigate the role of hydrocarbons (HC) in changing the petrophysical properties of rock by merging laboratory experiments, well data and static models focusing on the carbonate-bearing Majella reservoir. This reservoir represent an interesting analogue for the several oil fields discovered in the subsurface in the region, allowing a comparison of a wide range of geological and geophysical data at different scale. The investigated lithology is made of high porosity ramp calcarenites, structurally slightly affected by a superimposed fracture system and displaced by few major normal faults, with some minor strike-slip movements. Sets of rock specimens were selected in the field and in particular two groups were investigated: 1. clean rocks (without oil) and 2. HC bearing rocks (with different saturations). For both groups, density, porosity, P and S wave velocity, permeability and elastic moduli measurements at increasing confining pressure were conducted on cylindrical specimens at the HP-HT Laboratory of the Istituto Nazionale di Geofisica e Vulcanologia (INGV) in Rome, Italy. For clean samples at ambient pressure, laboratory porosity varies from 10 % up to 26 % and P wave velocity (Vp) spans from 4,1 km/s to 4,9 km/s and a very good correlation between Vp, Vs and porosity is observed. The P wave velocity at 100 MPa of confining pressure, ranges between 4,5 km/s and 5,2 km/s with a pressure independent Vp/Vs ratio of about 1,9. The presence of HC within the samples affects both Vp and Vs. In particular velocities increase with the presence of hydrocarbons proportionally respect to the amount of the filled

  18. Process-based reconstruction of sedimentary rocks, sandy soils and soil aggregates

    NASA Astrophysics Data System (ADS)

    Vasilyev, Roman; Gerke, Kirill; Čapek, Pavel; Karsanina, Marina; Korost, Dmitry

    2013-04-01

    There are three main approaches to model and reconstruct (using 2D cut(s), grain size distribution or some other limited information/properties) porous media: 1) statistical methods (correlation functions and simulated annealing, multi-point statistics, entropy methods), 2) sequential methods (sphere or other shapes granular packs), and 3) morphological methods. Each method has its own advantages and shortcomings, so there is no readily available solution and methods should be carefully chosen and tested for each particular media. Here we mainly focus on sequential process-based method due to its general simplicity and straightforward usability for different transformation modeling: diagenesis, mechanical compaction, erosion, etc. It is well known that process-based models for sandstone thin-sections give good transport properties after 3D reconstruction. This method is also useful for pore-network extraction validation. At first, polydisperse sphere packs are created using two different techniques: (1) modified Lubachevsky-Stillinger method, and (2) original Øren-Bakke method with global minimal or local minimal energy ballistic disposition rules. The latter are known to create anisotropic packs with kissing numbers different from real sedimentary materials. During the next step, the third phase (clay minerals for rocks and clay and organic matter for soils) is grown within pore space based on Voronoi tesselation to determine distances to the nearest grains. Input parameters, i.e., grain size distributions and porosities are determined using laboratory methods or image analysis for real porous media: sandstones, sandy soils and soil aggregates. To model soil aggregate structure a gravitational algorithm is used there a set of granules falls onto a gravity center in the middle of the aggregate. All further steps are similar to that of sedimentary rocks and soils. Resulted 3D reconstructions are compared with original 3D structures obtained using X

  19. Petrologic and petrophysical evaluation of the Dallas Center Structure, Iowa, for compressed air energy storage in the Mount Simon Sandstone.

    SciTech Connect

    Heath, Jason E.; Bauer, Stephen J.; Broome, Scott Thomas; Dewers, Thomas A.; Rodriguez, Mark A

    2013-03-01

    The Iowa Stored Energy Plant Agency selected a geologic structure at Dallas Center, Iowa, for evaluation of subsurface compressed air energy storage. The site was rejected due to lower-than-expected and heterogeneous permeability of the target reservoir, lower-than-desired porosity, and small reservoir volume. In an initial feasibility study, permeability and porosity distributions of flow units for the nearby Redfield gas storage field were applied as analogue values for numerical modeling of the Dallas Center Structure. These reservoir data, coupled with an optimistic reservoir volume, produced favorable results. However, it was determined that the Dallas Center Structure cannot be simplified to four zones of high, uniform permeabilities. Updated modeling using field and core data for the site provided unfavorable results for air fill-up. This report presents Sandia National Laboratories petrologic and petrophysical analysis of the Dallas Center Structure that aids in understanding why the site was not suitable for gas storage.

  20. Petrophysics of Lower Silurian sandstones and integration with the tectonic-stratigraphic framework, Appalachian basin, United States

    USGS Publications Warehouse

    Castle, J.W.; Byrnes, A.P.

    2005-01-01

    Petrophysical properties were determined for six facies in Lower Silurian sandstones of the Appalachian basin: fluvial, estuarine, upper shoreface, lower shoreface, tidal channel, and tidal flat. Fluvial sandstones have the highest permeability for a given porosity and exhibit a wide range of porosity (2-18%) and permeability (0.002-450 md). With a transition-zone thickness of only 1-6 m (3-20 ft), fluvial sandstones with permeability greater than 5 md have irreducible water saturation (Siw) less than 20%, typical of many gas reservoirs. Upper shoreface sandstones exhibit good reservoir properties with high porosity (10-21%), high permeability (3-250 md), and low S iw (<20%). Lower shoreface sandstones, which are finer grained, have lower porosity (4-12%), lower permeability (0.0007-4 md), thicker transition zones (6-180 m [20-600 ft]), and higher S iw. In the tidal-channel, tidal-flat, and estuarine facies, low porosity (average < 6%), low permeability (average < 0.02 md), and small pore throats result in large transition zones (30-200 m; 100-650 ft) and high water saturations. The most favorable reservoir petrophysical properties and the best estimated production from the Lower Silurian sandstones are associated with fluvial and upper shoreface facies of incised-valley fills, which we interpret to have formed predominantly in areas of structural recesses that evolved from promontories along a collisional margin during the Taconic orogeny. Although the total thickness of the sandstone may not be as great in these areas, reservoir quality is better than in adjacent structural salients, which is attributed to higher energy depositional processes and shallower maximum burial depth in the recesses than in the salients. Copyright ??2005. The American Association of Petroleum Geologists. All rights reserved.

  1. Calculation of thermal conductivity, thermal diffusivity and specific heat capacity of sedimentary rocks using petrophysical well logs

    NASA Astrophysics Data System (ADS)

    Fuchs, Sven; Balling, Niels; Förster, Andrea

    2015-12-01

    In this study, equations are developed that predict for synthetic sedimentary rocks (clastics, carbonates and evapourates) thermal properties comprising thermal conductivity, specific heat capacity and thermal diffusivity. The rock groups are composed of mineral assemblages with variable contents of 15 major rock-forming minerals and porosities of 0-30 per cent. Petrophysical properties and their well-logging-tool-characteristic readings were assigned to these rock-forming minerals and to pore-filling fluids. Relationships are explored between each thermal property and other petrophysical properties (density, sonic interval transit time, hydrogen index, volume fraction of shale and photoelectric absorption index) using multivariate statistics. The application of these relations allows computing continuous borehole profiles for each rock thermal property. The uncertainties in the prediction of each property vary depending on the selected well-log combination. Best prediction is in the range of 2-8 per cent for the specific heat capacity, of 5-10 per cent for the thermal conductivity, and of 8-15 for the thermal diffusivity, respectively. Well-log derived thermal conductivity is validated by laboratory data measured on cores from deep boreholes of the Danish Basin, the North German Basin, and the Molasse Basin. Additional validation of thermal conductivity was performed by comparing predicted and measured temperature logs. The maximum deviation between these logs is <3 °C. The thermal-conductivity calculation allowed an evaluation of the depth range in which the palaeoclimatic effect on the subsurface temperature field can be observed in the North German Basin. This effect reduces the surface heat-flow density by 25 mW m-2.

  2. Geological and Petrophysical Characterization of the Ferron Sandstone for 3-D Simulation of a Fluvial-Deltaic Reservoir.

    SciTech Connect

    Allison, M.L.

    1997-07-01

    The objective of this project is to develop a comprehensive, interdisciplinary, and quantitative characterization of a fluvial- deltaic reservoir which will allow realistic inter-well and reservoir-scale modeling to be constructed for improved oil-field development in similar reservoirs world-wide. The geological and petrophysical properties of the Cretaceous Ferron Sandstone in east-central Utah will be quantitatively determined. Both new and existing data will be integrated into a three-dimensional representation of spatial variations in porosity, storativity, and tensorial rock permeability at a scale appropriate for inter-well to regional-scale reservoir simulation. Results could improve reservoir management through proper infill and extension drilling strategies, reduction of economic risks, increased recovery from existing oil fields, and more reliable reserve calculations. Transfer of the project results to the petroleum industry is an integral component of the project. Two activities continued this quarter as part of the geological and petrophysical characterization of the fluvial-deltaic Ferron Sandstone: (1) evaluation of the Ivie Creek case-study area and (2) technology transfer. The Ivie Creek case-study evaluation work during the quarter focused on the two parasequence sets, the Kf-1 and Kf-2, in the lower Ferron Sandstone. This work included: (1) clinoform characterization, (2) parasequence characterization from elevation and isopach maps, and (3) three-dimensional facies modeling. Scaled photomosaic panels from the Ivie Creek amphitheater (south-facing outcrop belt) and Quitchupah Canyon (Fig. 1) provide a deterministic framework for two apparent-dip cross sections. These panels along with other photomosaic coverage and data from five drill holes, ten stratigraphic sections, and 22 permeability transacts (Fig. 1), acquired during two field seasons, provided the necessary information for this geologic evaluation and creation of the models to be used

  3. Effect of texture on petrophysical properties of dolomite: Evidence from the Cambrian-Ordovician of southeastern Missouri

    SciTech Connect

    Woody, R.E.; Gregg, J.M.; Koederitz, L.F.

    1996-01-01

    Two basic textural types of dolomite exist: (1) planar dolomite, which forms in both shallow and burial diagenetic environments; and (2) nonplanar dolomite, which develops at temperatures in excess of 50{degrees}C in the burial environment by dolomitization of limestone or neomorphic recrystallization of preexisting dolomite. Variation in dolomite texture is the result of variation in the diagenetic history of the rock unit. Cambrian-Ordovician dolomites were collected from core and outcrop throughout southeastern Missouri. Effective porosity and permeability were determined using helium porosimetry and gas permeability. Total porosity and texture type were determined from thin-section analysis. Pore throat geometry was evaluated using mercury capillary pressure curves and scanning electron microscope (SEM) examination of pore casts. Two porosity-permeability populations exist for planar dolomite: (1) planar-e (euhedral) dolomite, where permeability strongly varies with porosity; and (2) planar-s (subhedral) dolomite, where permeability is lower than in planar-e dolomite and does not increase as rapidly with increasing porosity. In planar-e dolomite, capillary pressure data and SEM pore cast analysis indicate uniform pore throat sizes and well-interconnected pore systems. Uniform throat sizes and well-connected pore systems do not exist in planar-s dolomite. This most likely is due to continued cementation during diagenesis. The petrophysical properties of dolomite petroleum reservoirs and aquifers vary depending on the petrographic texture of the dolomite. Understanding diagenetic history, and crystal textures that may result because of various diagenetic conditions, can be a predictor of petrophysical properties of dolomite reservoirs.

  4. Field-scale prediction of soil moisture patterns by means of a fuzzy c-means clustering algorithm, digital elevation data, and sparse TDR measurements

    NASA Astrophysics Data System (ADS)

    Schröter, Ingmar; Paasche, Hendik; Dietrich, Peter; Wollschläger, Ute

    2014-05-01

    Soil moisture is a key variable of the hydrological cycle. For example, it controls partitioning of rainfall into a runoff and an infiltration component and modulating physical, chemical and biological processes within the soil. For a better understanding of these processes, knowledge about the spatio-temporal distribution of soil moisture is indispensable. For the field to the small catchment scale with survey areas up to a few square kilometres, there are numerous new and innovative ground-based and remote sensing technologies available which have great potential to provide temporal information about soil moisture patterns. The aim of this work is to design an optimal soil moisture monitoring program for a low-mountain catchment in central Germany. In a first step, the fuzzy c-means clustering technique (Paasche et al., 2006) was used to identify structure-relevant patterns in a set of different terrain attributes derived from a DEM. Based on these patterns optimal measurement locations were identified to conduct in-situ soil moisture measurements. To consider different wetting and drying states in the catchment, several TDR measurement campaigns were conducted from April to October 2013. The TDR measurements have been integrated with the structure-relevant patterns obtained by the fuzzy cluster analysis to regionally predict soil moisture. In this study, we outline the conceptual framework of this integrative approach and present first results from field measurements. The results of the project are expected to improve the monitoring and understanding of small catchment-scale hydrological processes and to contribute to a better representation of soil moisture dynamics in physically-based, hydrological models operating at the field to the small catchment scale. Reference: Paasche, H., J. Tronicke, K. Holliger, A.G. Green, and H. Maurer (2006): Integration of diverse physical-property models: Subsurface zonation and petrophysical parameter estimation based on fuzzy

  5. Flow Separation in Undisturbed Soil Using Multiple Anionic Tracers. Part 2. Steady-State Core-Scale Rainfall and Return Flows and Determination of Dispersion Parameters

    NASA Astrophysics Data System (ADS)

    Henderson, D. E.; Reeves, A. D.; Beven, K. J.; Chappell, N. A.

    1996-11-01

    A series of experiments designed to study the separation of flow components from two large undisturbed cores under steady-state rainfall (downward) and return (upward) flows under near-saturated conditions is summarized. The experiments were conducted on soil columns collected from Lancaster University and the Slapton Wood catchment, Devon. The use of the relatively conservative tracers, potassium bromide, o-(trifluoromethyl)benzoic acid and 2,6-difluorobenzoic acid and a combination of application rates made it possible to quantify the different sources of water contributing to the discharge hydrographs. There is significant retention of tracer within the cores, despite the application of several pore volumes of water. The use of steady flow conditions allowed the determination of dispersion coefficients, dispersivity and proportion of mobile water content parameters of the advection-dispersion equation. It was found that there were significant differences between the dispersivities at different flow-rates under upward and downward flux conditions and that in the undisturbed cores studied here the apparent proportions of mobile pore water ranged between 0.33 and 1.0, with an apparently complex relationship to flux rate. Prediction of transport in undisturbed soil remains problematic and tracer experiments will continue to be needed to provide a fundamental understanding of the complex flow processes involved.

  6. Soil thermal resistivity and thermal stability measuring instrument. Volume 2: Manual for operation and use of the thermal property analyzer and statistical weather analysis program to determine thermal design parameters

    NASA Astrophysics Data System (ADS)

    Boggs, S. A.; Radhakrishna, H. S.; Chu, F. Y.; Ford, G. L.; Griffin, J. D. A.; Steinmanis, J.

    1981-11-01

    Numerous considerations influence the thermal design of an underground power cable, including the soil thermal resistivity, thermal diffusivity and thermal stability. Each of these properties is a function of soil moisture which is in turn a function of past weather, soil composition, and biological burden. The Neher-McGrath formalism has been widely used for thermal cable design. However, this formalism assumes knowledge of soil thermal properties (resistivity and diffusivity). For design purposes, these parameters should be treated statistically, since weather varies greatly from year to year. As well, soil thermal property surveys are normally required along the route to assess the thermal quality of the native soil. This project is intended to fill the gap between the need to carry out thermal design and the use of the Neher-McGrath formalism which is normally employed. This goal has been addressed through: development of instrumentation and methods of measuring soil thermal properties in situ and in the laboratory; recommendation of methods for conducting soil surveys along a proposed cable route and of assessing the thermal quality of soils; and development of a computerized method to treat soil thermal design parameters on a statistical basis using computerized weather records as supplied by the US Environmental Data Service. The use of the methods and instrumentation developed as a result of this contract should permit less conservative thermal design thereby improving the economics of underground transmission. As well, these techniques and instrumentation facilitate weather-dependent prediction of cable ampacity for installed cables, monitoring of backfill thermal stability, and many other new practices.

  7. The Impact of Carrot Enriched in Iodine through Soil Fertilization on Iodine Concentration and Selected Biochemical Parameters in Wistar Rats.

    PubMed

    Piątkowska, Ewa; Kopeć, Aneta; Bieżanowska-Kopeć, Renata; Pysz, Mirosław; Kapusta-Duch, Joanna; Koronowicz, Aneta Agnieszka; Smoleń, Sylwester; Skoczylas, Łukasz; Ledwożyw-Smoleń, Iwona; Rakoczy, Roksana; Maślak, Edyta

    2016-01-01

    Iodine is one of the trace elements which are essential for mammalian life. The major objective of iodine biofortification of plants is to obtain food rich in this trace element, which may increase its consumption by various populations. Additionally, it may reduce the risk of iodine deficiency diseases. In this research for the first time we have assessed the bioavailability of iodine from raw or cooked carrot biofortified with this trace element on iodine concentration in selected tissues and various biochemical parameters as well as mRNA expression of some genes involved in iodine metabolism in Wistar rats. Statistically, a significantly higher iodine level was determined in urine, faeces and selected tissues of rats fed a diet containing biofortified raw carrot as compared to a diet without iodine and a diet containing control cooked carrot. Biofortified raw carrot significantly increased triiodothyronine concentration as compared to animals from other experimental groups. The highest thyroid stimulating hormone level was determined in rats fed control cooked carrots. mRNA expression of selected genes was affected by different dietary treatment in rats' hearts. Biofortified raw and cooked carrot could be taken into account as a potential source of iodine in daily diets to prevent iodine deficiency in various populations. PMID:27043135

  8. The Impact of Carrot Enriched in Iodine through Soil Fertilization on Iodine Concentration and Selected Biochemical Parameters in Wistar Rats

    PubMed Central

    Piątkowska, Ewa; Kopeć, Aneta; Bieżanowska-Kopeć, Renata; Pysz, Mirosław; Kapusta-Duch, Joanna; Koronowicz, Aneta Agnieszka; Smoleń, Sylwester; Skoczylas, Łukasz; Ledwożyw-Smoleń, Iwona; Rakoczy, Roksana; Maślak, Edyta

    2016-01-01

    Iodine is one of the trace elements which are essential for mammalian life. The major objective of iodine biofortification of plants is to obtain food rich in this trace element, which may increase its consumption by various populations. Additionally, it may reduce the risk of iodine deficiency diseases. In this research for the first time we have assessed the bioavailability of iodine from raw or cooked carrot biofortified with this trace element on iodine concentration in selected tissues and various biochemical parameters as well as mRNA expression of some genes involved in iodine metabolism in Wistar rats. Statistically, a significantly higher iodine level was determined in urine, faeces and selected tissues of rats fed a diet containing biofortified raw carrot as compared to a diet without iodine and a diet containing control cooked carrot. Biofortified raw carrot significantly increased triiodothyronine concentration as compared to animals from other experimental groups. The highest thyroid stimulating hormone level was determined in rats fed control cooked carrots. mRNA expression of selected genes was affected by different dietary treatment in rats’ hearts. Biofortified raw and cooked carrot could be taken into account as a potential source of iodine in daily diets to prevent iodine deficiency in various populations. PMID:27043135

  9. The Impact of Carrot Enriched in Iodine through Soil Fertilization on Iodine Concentration and Selected Biochemical Parameters in Wistar Rats.

    PubMed

    Piątkowska, Ewa; Kopeć, Aneta; Bieżanowska-Kopeć, Renata; Pysz, Mirosław; Kapusta-Duch, Joanna; Koronowicz, Aneta Agnieszka; Smoleń, Sylwester; Skoczylas, Łukasz; Ledwożyw-Smoleń, Iwona; Rakoczy, Roksana; Maślak, Edyta

    2016-01-01

    Iodine is one of the trace elements which are essential for mammalian life. The major objective of iodine biofortification of plants is to obtain food rich in this trace element, which may increase its consumption by various populations. Additionally, it may reduce the risk of iodine deficiency diseases. In this research for the first time we have assessed the bioavailability of iodine from raw or cooked carrot biofortified with this trace element on iodine concentration in selected tissues and various biochemical parameters as well as mRNA expression of some genes involved in iodine metabolism in Wistar rats. Statistically, a significantly higher iodine level was determined in urine, faeces and selected tissues of rats fed a diet containing biofortified raw carrot as compared to a diet without iodine and a diet containing control cooked carrot. Biofortified raw carrot significantly increased triiodothyronine concentration as compared to animals from other experimental groups. The highest thyroid stimulating hormone level was determined in rats fed control cooked carrots. mRNA expression of selected genes was affected by different dietary treatment in rats' hearts. Biofortified raw and cooked carrot could be taken into account as a potential source of iodine in daily diets to prevent iodine deficiency in various populations.

  10. Response of key soil parameters during compost-assisted phytostabilization in extremely acidic tailings: effect of plant species.

    PubMed

    Solís-Dominguez, Fernando A; White, Scott A; Hutter, Travis Borrillo; Amistadi, Mary Kay; Root, Robert A; Chorover, Jon; Maier, Raina M

    2012-01-17

    Phytostabilization of mine tailings acts to mitigate both eolian dispersion and water erosion events which can disseminate barren tailings over large distances. This technology uses plants to establish a vegetative cover to permanently immobilize contaminants in the rooting zone, often requiring addition of an amendment to assist plant growth. Here we report the results of a greenhouse study that evaluated the ability of six native plant species to grow in extremely acidic (pH ∼ 2.5) metalliferous (As, Pb, Zn: 2000-3000 mg kg(-1)) mine tailings from Iron King Mine Humboldt Smelter Superfund site when amended with a range of compost concentrations. Results revealed that three of the six plant species tested (buffalo grass, mesquite, and catclaw acacia) are good candidates for phytostabilization at an optimum level of 15% compost (w/w) amendment showing good growth and minimal shoot accumulation of metal(loid)s. A fourth candidate, quailbush, also met all criteria except for exceeding the domestic animal toxicity limit for shoot accumulation of zinc. A key finding of this study was that the plant species that grew most successfully on these tailings significantly influenced key tailings parameters; direct correlations between plant biomass and both increased tailings pH and neutrophilic heterotrophic bacterial counts were observed. We also observed decreased iron oxidizer counts and decreased bioavailability of metal(loid)s mainly as a result of compost amendment. Taken together, these results suggest that the phytostabilization process reduced tailings toxicity as well as the potential for metal(loid) mobilization. This study provides practical information on plant and tailings characteristics that is critically needed for successful implementation of assisted phytostabilization on acidic, metalliferous mine tailings sites. PMID:22191663

  11. Response of key soil parameters during compost-assisted phytostabilization in extremely acidic tailings: effect of plant species.

    PubMed

    Solís-Dominguez, Fernando A; White, Scott A; Hutter, Travis Borrillo; Amistadi, Mary Kay; Root, Robert A; Chorover, Jon; Maier, Raina M

    2012-01-17

    Phytostabilization of mine tailings acts to mitigate both eolian dispersion and water erosion events which can disseminate barren tailings over large distances. This technology uses plants to establish a vegetative cover to permanently immobilize contaminants in the rooting zone, often requiring addition of an amendment to assist plant growth. Here we report the results of a greenhouse study that evaluated the ability of six native plant species to grow in extremely acidic (pH ∼ 2.5) metalliferous (As, Pb, Zn: 2000-3000 mg kg(-1)) mine tailings from Iron King Mine Humboldt Smelter Superfund site when amended with a range of compost concentrations. Results revealed that three of the six plant species tested (buffalo grass, mesquite, and catclaw acacia) are good candidates for phytostabilization at an optimum level of 15% compost (w/w) amendment showing good growth and minimal shoot accumulation of metal(loid)s. A fourth candidate, quailbush, also met all criteria except for exceeding the domestic animal toxicity limit for shoot accumulation of zinc. A key finding of this study was that the plant species that grew most successfully on these tailings significantly influenced key tailings parameters; direct correlations between plant biomass and both increased tailings pH and neutrophilic heterotrophic bacterial counts were observed. We also observed decreased iron oxidizer counts and decreased bioavailability of metal(loid)s mainly as a result of compost amendment. Taken together, these results suggest that the phytostabilization process reduced tailings toxicity as well as the potential for metal(loid) mobilization. This study provides practical information on plant and tailings characteristics that is critically needed for successful implementation of assisted phytostabilization on acidic, metalliferous mine tailings sites.

  12. The early diagenetic and PETROphysical behaviour of recent cold-water CARbonate mounds in Deep Environments (PETROCARDE)

    NASA Astrophysics Data System (ADS)

    Foubert, Anneleen; Pirlet, Hans; Thierens, Mieke; de Mol, Ben; Henriet, Jean-Pierre; Swennen, Rudy

    2010-05-01

    Sub-recent cold-water carbonate mounds localized in deeper slope settings on the Atlantic continental margins cannot be any longer neglected in the study of carbonate systems. They clearly play a major role in the dynamics of mixed siliciclastic-carbonate and/or carbonate-dominated continental slopes. Carbonate accumulation rates of cold-water carbonate mounds are about 4 to 12 % of the carbonate accumulation rates of tropical shallow-water reefs but exceed the carbonate accumulation rates of their slope settings by a factor of 4 to 12 (Titschack et al., 2009). These findings emphasize the importance of these carbonate factories as carbonate niches on the continental margins. The primary environmental architecture of such carbonate bodies is well-characterized. However, despite proven evidences of early diagenesis overprinting the primary environmental record (e.g. aragonite dissolution) (Foubert & Henriet, 2009), the extent of early diagenetic and biogeochemical processes shaping the petrophysical nature of mounds is until now not yet fully understood. Understanding (1) the functioning of a carbonate mound as biogeochemical reactor triggering early diagenetic processes and (2) the impact of early diagenesis on the petrophysical behaviour of a carbonate mound in space and through time are necessary (vital) for the reliable prediction of potential late diagenetic processes. Approaching the fossil carbonate mound record, through a profound study of recent carbonate bodies is innovative and will help to better understand processes observed in the fossil mound world (such as cementation, brecciation, fracturing, etc…). In this study, the 155-m high Challenger mound (Porcupine Seabight, SW of Ireland), drilled during IODP Expedition 307 aboard the R/V Joides Resolution (Foubert & Henriet, 2009), and mounds from the Gulf of Cadiz (Moroccan margin) will be discussed in terms of early diagenetic processes and petrophysical behaviour. Early differential diagenesis

  13. Effective porosity and density of carbonate rocks (Maynardville Limestone and Copper Ridge Dolomite) within Bear Creek Valley on the Oak Ridge Reservation based on modern petrophysical techniques

    SciTech Connect

    Dorsch, J.

    1997-02-01

    The purpose of this study is to provide quantitative data on effective porosity of carbonate rock from the Maynardville Limestone and Copper Ridge Dolomite within Bear Creek Valley based on modern petrophysical techniques. The data will be useful for groundwater-flow and contaminant-flow modeling in the vicinity of the Y-12 Plant on the Oak Ridge Reservation (ORR). Furthermore, the data provides needed information on the amount of interconnected pore space potentially available for operation of matrix diffusion as a transport process within the fractured carbonate rock. A second aspect of this study is to compare effective porosity data based on modern petrophysical techniques to effective porosity data determined earlier by Goldstrand et al. (1995) with a different technique. An added bonus of the study is quantitative data on the bulk density and grain density of dolostone and limestone of the Maynardville Limestone and Copper Ridge Dolomite which might find use for geophysical modeling on the ORR.

  14. Facies and petrophysical modelling of a thick lower cretaceous tsunami deposit in E Spain: Up-scaling from sample to outcrop scales

    NASA Astrophysics Data System (ADS)

    Veloso, Fernanda M. L.; Liesa, Carlos L.; Soria, Ana R.; Meléndez, Nieves; Frykman, Peter

    2016-08-01

    The tsunami deposit (up to 3 m thick) of the Cretaceous Camarillas Formation in the Galve sub-basin (eastern Spain) is characterized by a large lateral extent (35 km2) and facies uniformity, consisting in fine to coarse subarkosic-arkosic sandstones. At the scale of outcrop observation, different lithofacies were distinguished and related to sedimentation processes. Sand facies distribution conditioned the facies heterogeneity at both mesoscopic or outcrop scales (10- 1-101 m scale) and sample scale (10- 3-10- 2 m). The sample features were up-scaled to that of a facies model using probability functions and variograms as well as to outcrop-scale data (geometry and size) of facies distribution, and it showed a good correlation with the facies distribution at the outcrop. Porosity is strongly correlated to permeability and the pairs of porosity and permeability values fall into the global hydraulic element (GHEs) 5, so that they can be up-scaled into reservoir models in terms of hydraulic properties. From data analysis, no apparent link between sand sorting and porosity and permeability values was observed. The petrophysical models, which were independent of facies models, were up-scaled taking into account the porosity and permeability values from sample data and the statistical analysis of their distribution along the outcrop. The permeability model was carried out as a function of porosity by applying a linear relation, which simplified the modelling process and discarded permeability uncertainties linked to facies distribution in the deposit. In spite of different source data, the petrophysical models show a distribution of lower and higher values that resembles the facies model. Consequently, our modelling results clearly suggest the link of facies type and their grain size distributions with the petrophysical properties into the deposit. Consistency between facies and petrophysical models and outcrop-scale observations make it possible to extrapolate to other

  15. X-ray CT analyses, models and numerical simulations: a comparison with petrophysical analyses in an experimental CO2 study

    NASA Astrophysics Data System (ADS)

    Henkel, Steven; Pudlo, Dieter; Enzmann, Frieder; Reitenbach, Viktor; Albrecht, Daniel; Ganzer, Leonhard; Gaupp, Reinhard

    2016-06-01

    An essential part of the collaborative research project H2STORE (hydrogen to store), which is funded by the German government, was a comparison of various analytical methods for characterizing reservoir sandstones from different stratigraphic units. In this context Permian, Triassic and Tertiary reservoir sandstones were analysed. Rock core materials, provided by RWE Gasspeicher GmbH (Dortmund, Germany), GDF Suez E&P Deutschland GmbH (Lingen, Germany), E.ON Gas Storage GmbH (Essen, Germany) and RAG Rohöl-Aufsuchungs Aktiengesellschaft (Vienna, Austria), were processed by different laboratory techniques; thin sections were prepared, rock fragments were crushed and cubes of 1 cm edge length and plugs 3 to 5 cm in length with a diameter of about 2.5 cm were sawn from macroscopic homogeneous cores. With this prepared sample material, polarized light microscopy and scanning electron microscopy, coupled with image analyses, specific surface area measurements (after Brunauer, Emmet and Teller, 1938; BET), He-porosity and N2-permeability measurements and high-resolution microcomputer tomography (μ-CT), which were used for numerical simulations, were applied. All these methods were practised on most of the same sample material, before and on selected Permian sandstones also after static CO2 experiments under reservoir conditions. A major concern in comparing the results of these methods is an appraisal of the reliability of the given porosity, permeability and mineral-specific reactive (inner) surface area data. The CO2 experiments modified the petrophysical as well as the mineralogical/geochemical rock properties. These changes are detectable by all applied analytical methods. Nevertheless, a major outcome of the high-resolution μ-CT analyses and following numerical data simulations was that quite similar data sets and data interpretations were maintained by the different petrophysical standard methods. Moreover, the μ-CT analyses are not only time saving, but also

  16. Influence of the timing of HC injection on the preservation of petrophysical properties of carbonate reservoirs at great depth

    NASA Astrophysics Data System (ADS)

    Neveux, Lucille; Grgic, Dragan; Pironon, Jacques; Carpentier, Cédric; Girard, Jean-Pierre

    2013-04-01

    In the oil industry, the preservation of petrophysical properties at great depth may lead to the existence of a deeply buried reservoir (DBR), a favoured target in the field of petroleum exploration and exploitation. The accurate prediction of reservoir quality requires an understanding of the key controlling diagenetic processes. Pressure solution is one of the main processes happening during diagenesis and being responsible for the evolution of porosity and permeability in many reservoirs. However, others processes may potentially act upon carbonate rocks during diagenesis: the timing of oil arrival is one of these processes. The aim of this study is to investigate experimentally the influence of oil injection and timing of this injection on the pressure solution process and thus on carbonate petrophysical properties. The experiments were performed using a subsurface consolidated carbonate rock and a specifically designed experimental apparatus, enabling the simulation of in situ conditions (pressure/stresses and temperature) of deeply buried reservoirs. Three experiments were realised with different fluids and injection conditions, namely meteoric fluid as the interstitial fluid, early saturation in oil of the sample followed by the injection of a meteoric fluid, late injection of oil in a sample initially saturated with a meteoric fluid. The results obtained in this study showed that without oil in the interstitial fluid, the main diagenetic process is the pressure solution creep (PSC). This process reduces by three the initial porosity but don't have any significant influence on permeability. When the sample was initially saturated with oil before the injection of the meteoric fluid, the process of PSC was inhibited. In this case, the porosity showed a slight decrease and the permeability showed a strong decrease from 23 mD to 1 mD. When an initially saturated (with a meteoric fluid) sample undergone a late injection of oil, the porosity was not preserved and

  17. Atlas of soil reflectance properties

    NASA Technical Reports Server (NTRS)

    Stoner, E. R.; Baumgardner, M. F.; Biehl, L. L.; Robinson, B. F.

    1979-01-01

    A compendium of soil spectral reflectance curves together with soil test results and site information is presented in an abbreviated manner listing those soil properties most important in influencing soil reflectance. Results are presented for 251 soils from 39 states and Brazil. A narrative key describes relationships between soil parameters and reflectance curves. All soils are classified according to the U.S. soil taxonomy and soil series name for ease of identification.

  18. Feasibility of calculating petrophysical properties in tight-sand reservoirs using neural networks. Final report, October 1989-July 1991

    SciTech Connect

    Urquidi-Macdonald, M.; Javitz, H.S.; Park, W.; Lee, J.D.; Bergman, A.

    1991-07-01

    The objective of the research was to determine the feasibility of using neural networks to estimate petrophysical properties in tight sand reservoirs. A second objective was to gain some experience concerning how to approach the development of a future prototype, including what should be done and what should be avoided. Gas Research Institute (GRI) focused the project on tight sands because they contain enormous gas reserves and their complicated lithology represents a challenge to log analysts. The data were supplied by GRI from two of its geographically proximate experimental wells in tight sand formations. The nets were tested in sections of those wells that were not used for training, and in two other wells, one in a geographically close but geologically unrelated formation and one in Wyoming. The feasibility testing demonstrated that the relatively simple neural networks developed have comparable accuracy with standard logging analysis estimates in wells that contributed data to the training set. Transportability of the network was tested by using core measurements in two wells in which the nets were not trained, with inconclusive results. Recommendations were made to increase the accuracy of the neural networks.

  19. Core handling, sedimentology, and petrophysical log response of a horizontal core, Barque field, United Kingdom sector, southern North Sea

    SciTech Connect

    Maskall, R. ); Reid, I. ); Urquhart, M. Shell U.K. Exploration and Production, Aberdeen )

    1994-03-01

    With the growing number of horizontal holes being drilled, petroleum geologists must handle increasing amounts of material having greater lateral than vertical extent. This requires novel techniques in description, interpretation, and data manipulation. This paper described the core handling and descriptive techniques used for a heterogeneous 28.6 m horizontal core from the eolian Rotliegende reservoir of the Barque gas field in the United Kingdom southern North Sea. The core is subparallel to structural dip, slowly cutting down stratigraphically but sampling only a limited extent (laterally or vertically) of the reservoir. One facies boundary can be traced for about 12 m along the core, and for a significant proportion of the core, two facies with markedly different reservoir properties occur across the same 10-cm core diameter. The core is unrepresentative of the reservoir, as described from vertical wells, in two ways: the overall lithofacies composition in the core is comparatively biased toward poor-quality (water-laid) facies, and the presence of a thin cemented layer in the normally better quality (eolian) facies markedly decreases their average porosity/permeability. Care must be taken in extrapolating plug data from the core to field models. Apparently, contradictory wireline responses are explained (through calibration to the core and by consideration of the physical basis of petrophysical log responses), allowing the construction of facies models covering the formation around the borehole. 14 refs., 11 figs., 3 tabs.

  20. Temporal variability in bioassays of the stomatal ammonia compensation point in relation to plant and soil nitrogen parameters in intensively managed grassland

    NASA Astrophysics Data System (ADS)

    Mattsson, M.; Herrmann, B.; David, M.; Loubet, B.; Riedo, M.; Theobald, M. R.; Sutton, M. A.; Bruhn, D.; Neftel, A.; Schjoerring, J. K.

    2009-02-01

    The exchange of ammonia between crop canopies and the atmosphere depends on a range of plant parameters and climatic conditions. However, little is known about effects of management factors. We have here investigated the stomatal ammonia compensation point in response to cutting and fertilization of a grass sward dominated by Lolium perenne. Tall grass had a very low NH3 compensation point (around 1 nmol mol-1), reflecting the fact that leaf nitrogen (N) concentration was very low. During re-growth after cutting, leaf tissue concentrations of NO3-, NH4+, soluble N and total N increased along with apoplastic NH4+ concentrations. In contrast, apoplastic pH decreased resulting in largely unaltered NH3 compensation points. Nitrogen fertilization one week after cutting caused the apoplastic NH4+ concentration of the newly emerging leaves to increase dramatically. The NH3 compensation point peaked between 15 and 25 nmol mol-1 the day after the fertiliser was applied and thereafter decreased over the following 10 days until reaching the same level as before fertilisation. Ammonium concentrations in leaf apoplast, bulk tissue and litter were positively correlated (P=0.001) throughout the experimental period. Bulk tissue NH4+ concentrations, total plant N and soil NH4+ concentrations also showed a positive correlation. A very high potential for NH3 emission was shown by the plant litter.

  1. Influence of the pesticides glyphosate, chlorpyrifos and atrazine on growth parameters of nonochratoxigenic Aspergillus section Nigri strains isolated from agricultural soils.

    PubMed

    Carranza, Cecilia S; Barberis, Carla L; Chiacchiera, Stella M; Magnoli, Carina E

    2014-01-01

    This investigation was undertake to determine the effect of glyphosate, chlorpyrifos and atrazine on the lag phase and growth rate of nonochratoxigenic A. niger aggregate strains growing on soil extract medium at -0.70, -2.78 and -7.06 MPa. Under certain conditions, the glyphosate concentrations used significantly increased micelial growth as compared to control. An increase of about 30% was observed for strain AN 251 using 5 and 20 mg L(-1) of glyphosate at -2.78 MPa. The strains behaved differently in the presence of the insecticide chlorpyrifos. A significant decrease in growth rate, compared to control, was observed for all strains except AN 251 at -2.78 MPa with 5 mg L(-1). This strain showed a significant increase in growth rate. With regard to atrazine, significant differences were observed only under some conditions compared to control. An increase in growth rate was observed for strain AN 251 at -2.78 MPa with 5 and 10 mg L(-1) of atrazine. By comparison, a reduction of 25% in growth rate was observed at -7.06 MPa and higher atrazine concentrations. This study shows that glyphosate, chlorpyrifos and atrazine affect the growth parameters of nonochratoxigenic A. niger aggregate strains under in vitro conditions.

  2. Petrophysical properties of carbonate rocks: example from the cretaceous Jandaira Formation, Potiguar basin - Brazil

    NASA Astrophysics Data System (ADS)

    Nogueira, Francisco; Soares, José; Bezerra, Francisco; Cavalcanti, Bruno; Cazarin, Caroline

    2015-04-01

    Carbonate sediments are prone to rapid and pervasive diagenetic alterations that change the mineralogy and pore structure within carbonate units. In particular, cementation and dissolution processes continuously modify the pore structure to create or destroy porosity. In extreme cases these modifications can completely change the mineralogy from calcite to dolomite, in the properties of rock for soil (Caliche), or reverse the pore distribution whereby original grains are dissolved to produce pores as the original pore space is filled with cement to form the rock. These processes are common in fractured carbonate units. All these modifications alter the elastic properties of the rock and, therefore, the sonic velocity. This study presents the result of relationship among diagenesis, porosity, grain density, and sonic velocity, in limestones, dolomites and caliche samples from the Jandaíra Formation, Potiguar basin, Brasil. This stratigraphic unit have been subjected to fracturing since the late Cretaceous. The rock and soil samples were collected in outcrops, prepared as plugs, and analyzed at ambient temperature. The porosity and grain density analysis were performed under ambient pressure, while elastic properties analyses were conducted with samples under confining pressure between 5 and 40 MPa. The result is a wide range of sonic velocity in carbonates, in which compressional-wave velocity (VP) ranges from 3507 to 6119 m/s and shear-wave velocity (VS) range from 2114 to 3451 m/s. The ratio VS1/VS2 indicate a level of anisotropy equal to 2%, without any clear relationship with porosity. The elastics properties are affected by rock alteration process or by modification of mineral composition, due to the presence of clay minerals and organic matter, The porosity and grain density values range from 3.2 to 21.5%, and 2.7 to 2.8 (g/cm3), respectively. The grain density analysis in the carbonate rocks indicate the existence of two groups: the first group of calcareous

  3. Facies distribution, depositional environment, and petrophysical features of the Sharawra Formation, Old Qusaiba Village, Central Saudi Arabia

    NASA Astrophysics Data System (ADS)

    Abbas, Muhammad Asif; Kaminski, Michael; Umran Dogan, A.

    2016-04-01

    The Silurian Sharawra Formation has great importance as it rests over the richest source rock of the Qusaiba Formation in central Saudi Arabia. The Sharawra Formation has four members including Jarish, Khanafriyah, Nayyal, and Zubliyat. The formation mainly consists of sandstone and siltstone with subordinate shale sequences. The lack of published research on this formation requires fundamental studies that can lay the foundation for future research. Three outcrops were selected from the Old Qusaiba Village in Central Saudi Arabia for field observations, petrographical and petrophysical study. Thin section study has been aided by quantitative mineralogical characterization using scanning electron microscopy - energy dispersive spectroscopy and powder x-ray diffraction (XRD) for both minerals, cements, and clay minerals (detrital and authigenic). The outcrops were logged in detail and nine different lithofacies have been identified. The thin section study has revealed the Sharawra Formation to be mainly subarkosic, while the mica content increases near to its contact with the Qusaiba Formation. The XRD data has also revealed a prominent change in mineralogy with inclusion of minerals like phlogopite and microcline with depths. Field observations delineated a prominent thinning of strata as lithofacies correlation clearly shows the thinning of strata in the southwestern direction. The absence of outcrop exposures further supports the idea of southwestern thinning of strata. This is mainly attributed to local erosion and the presence of thicker shale interbeds in the southeastern section, which was probably subjected to more intense erosion than the northwestern one. The Sharawra Formation rests conformably over the thick transgressive shale sequence, deposited during the post glacial depositional cycle. The lowermost massive sandstone bed of the Sharawra Formation represents the beginning of the regressive period. The shale interbeds in the lower part are evidence of

  4. Macro and micro nutrient uptake parameters and use efficiency in cacao genotypes influenced by deficient to excess levels of soil K

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cacao (Theobroma cacao L.) is an important economic crop for many of the tropical countries. Adequate levels of soil K are essential for good growth and achieving high cocoa bean yields. Soils under cacao invariably have low levels of plant available K to support good cacao growth. Growth chamber ex...

  5. Estimating effective roughness parameters of the L-MEB model for soil moisture retrieval using passive microwave observations from SMAPVEX12

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although there have been efforts to improve existing soil moisture retrieval algorithms, the ability to estimate soil moisture from passive microwave observations is still hampered by problems in accurately modeling the observed microwave signal. This paper focuses on the estimation of effective sur...

  6. Soil spectral characterization

    NASA Technical Reports Server (NTRS)

    Stoner, E. R.; Baumgardner, M. F.

    1981-01-01

    The spectral characterization of soils is discussed with particular reference to the bidirectional reflectance factor as a quantitative measure of soil spectral properties, the role of soil color, soil parameters affecting soil reflectance, and field characteristics of soil reflectance. Comparisons between laboratory-measured soil spectra and Landsat MSS data have shown good agreement, especially in discriminating relative drainage conditions and organic matter levels in unvegetated soils. The capacity to measure both visible and infrared soil reflectance provides information on other soil characteristics and makes it possible to predict soil response to different management conditions. Field and laboratory soil spectral characterization helps define the extent to which intrinsic spectral information is available from soils as a consequence of their composition and field characteristics.

  7. Evaluation of chemical parameters and ecotoxicity of a soil developed on gossan following application of polyacrylates and growth of Spergularia purpurea.

    PubMed

    Santos, Erika S; Abreu, Maria Manuela; de Varennes, Amarilis; Macías, Felipe; Leitão, Sara; Cerejeira, Maria José

    2013-09-01

    The aim of this study was to evaluate the chemical characteristics and ecotoxicity of a mine soil developed on gossan materials and amended with hydrophilic polyacrylate polymers after a growth cycle of Spergularia purpurea. Different acute bioassays (Daphnia magna immobilization; microalgae growth inhibition; germination and growth of lettuce and oat) were carried out with simulated leachates, pore water and soil samples. The germination and growth of native shrubs (Cistus ladanifer and Lavandula sampaioana) were also evaluated in the lysimeters where S. purpurea had grown. The soil had high total concentrations (g/kg) of Al (3.50-8.60), As (2.55-2.73), Cu (0.13-0.91) and Pb (4.48-6.16). However, the percentages of elements in aqueous extracts (simulating leachates, pore water, and the conditions of the rhizosphere soil) were small when compared to their total soil concentrations (less than 9% except for Na in leachates). Growth of S. purpurea and other natural colonization of plant species (Poaceae, Fabaceae and Asteraceae families) improved chemical characteristics but the application of the polyacrylate polymers contributed to a further improvement of soil quality. However, this was not sufficient to ensure the growth of a large number of shrubs despite a great germination rate. Among the several species used on the ecotoxicological assessment, the D. magna test was the only bioassay that showed a clear toxicity of soil leachates, suggesting the importance of using several ecotoxicological tests to assess the environmental risk of soil contamination and its rehabilitation. Although the studied soil can be considered contaminated taking into account the total soil concentrations of Al, As, Cu and Pb, the low concentrations of the same chemical elements in extractable solutions, that simulated the fractions really available for organisms, did not demonstrate a substantial toxic effects in the organisms and, consequently, negative impact on the environment.

  8. Impact of raw pig slurry and pig farming practices on physicochemical parameters and on atmospheric N2O and CH 4 emissions of tropical soils, Uvéa Island (South Pacific).

    PubMed

    Roth, E; Gunkel-Grillon, P; Joly, L; Thomas, X; Decarpenterie, T; Mappe-Fogaing, I; Laporte-Magoni, C; Dumelié, N; Durry, G

    2014-09-01

    Emissions of CH4 and N2O related to private pig farming under a tropical climate in Uvéa Island were studied in this paper. Physicochemical soil parameters such as nitrate, nitrite, ammonium, Kjeldahl nitrogen, total organic carbon, pH and moisture were measured. Gaseous soil emissions as well as physicochemical parameters were compared in two private pig farming strategies encountered on this island on two different soils (calcareous and ferralitic) in order to determine the best pig farming management: in small concrete pens or in large land pens. Ammonium levels were higher in control areas while nitrate and nitrite levels were higher in soils with pig slurry inputs, indicating that nitrification was the predominant process related to N2O emissions. Nitrate contents in soils near concrete pens were important (≥ 55 μg N/g) and can thus be a threat for the groundwater. For both pig farming strategies, N2O and CH4 fluxes can reach high levels up to 1 mg N/m(2)/h and 1 mg C/m(2)/h, respectively. CH4 emissions near concrete pens were very high (≥ 10.4 mg C/m(2)/h). Former land pens converted into agricultural land recover low N2O emission rates (≤ 0.03 mg N/m(2)/h), and methane uptake dominates. N2O emissions were related to nitrate content whereas CH4 emissions were found to be moisture dependent. As a result relating to the physicochemical parameters as well as to the gaseous emissions, we demonstrate that pig farming in large land pens is the best strategy for sustainable family pig breeding in Uvéa Islands and therefore in similar small tropical islands.

  9. Main flow path and chemical alteration in a marly hill prone to slope instability: assessment from petrophysical measurements and borehole image analysis.

    NASA Astrophysics Data System (ADS)

    Lofi, Johanna; Gautier, Stéphanie; Pezard, Philippe; Loggia, Didier; Garel, Emilie

    2010-05-01

    The principal driving force of slope movements is generally considered to be gravity, with the main triggering factor being the increase of pore pressures by the presence of water contained in the geological environment. It is however difficult to anticipate the rupture processes involved in deep seated landslides mainly because of the difficulty in estimating the mechanical behaviors at the scale of the hill slope which is characterized by heterogeneous structures with large and small scale discontinuities. Hydrogeological behaviors are also important parameters and the localization of the main flow paths and saturated zones is a fundamental stage of the slope evolution before and after failure. The processes involved in the rupture is also rock type dependant. Clay shales that have complicated structure at a small scale and are sensible to weathering are very prone to slope instability. In this context, this study focuses a non slided slope made of tectonised clay shales in the Draix Observatory (ORE DRAIX) of the southern Alps (France). The objectives were to characterise at several scales (several m - µm) the internal architecture and main structural and lithological discontinuities of the hill slope in order to locate preferential water flows within the system, and anticipate its possible evolution. This work is based on a mutli-disciplinary approach including petrophysical analyses in the laboratory, well pulse injection tests and downhole geophysical measurements. Optical and acoustical images have been used as an original and efficient tool for internal discontinuities characterization at several scales (several mm - several m) and potential active flow path detection. In all, the integration of measurements leads to propose a simple scenario of fluid circulation and chemical alteration of the hill slope. Owing to the very low permeability of the non altered black marl matrix, the open fractures evidenced from borehole images may be the primary pathways

  10. Geological and petrophysical characterization of the Ferron Sandstone for 3-D simulation of a fluvial-deltaic reservoir. Quarterly report, April 1--June 30, 1998

    SciTech Connect

    Chidsey, T.C. Jr.

    1998-07-01

    The objective of this project is to develop a comprehensive, interdisciplinary, and quantitative characterization of a fluvial-deltaic reservoir which will allow realistic inter-well and reservoir-scale modeling to be constructed for improved oil-field development in similar reservoirs world-wide. The geological and petrophysical properties of the Cretaceous Ferron Sandstone in east-central Utah will be quantitatively determined. Both new and existing data will be integrated into a three-dimensional representation of spatial variations in porosity, storativity, and tensorial rock permeability at a scale appropriate for inter-well to regional-scale reservoir simulation. Results could improve reservoir management through proper infill and extension drilling strategies, reduction of economic risks, increased recovery from existing oil fields, and more reliable reserve calculations. Transfer of the project results to the petroleum industry is an integral component of the project. Two activities continued this quarter as part of the geological and petrophysical characterization of the fluvial-deltaic Ferron Sandstone: (1) preparation of the project final report and (2) technology transfer.

  11. Geological and petrophysical characterization of the Ferron Sandstone for 3-D simulation of a fluvial-deltaic reservoir. Quarterly report, July 1--September 30, 1997

    SciTech Connect

    Allison, M.L.

    1997-11-01

    The objective of this project is to develop a comprehensive, interdisciplinary, and quantitative characterization of a fluvial-deltaic reservoir which will allow realistic inter-well and reservoir-scale modeling to be constructed for improved oil-field development in similar reservoirs world-wide. The geological and petrophysical properties of the Cretaceous Ferron Sandstone in east-central Utah will be quantitatively determined. Both new and existing data will be integrated into a three-dimensional representation of spatial variations in porosity, storativity, and tensorial rock permeability at a scale appropriate for inter-well to regional-scale reservoir simulation. Results could improve reservoir management through proper infill and extension drilling strategies, reduction of economic risks, increased recovery from existing oil fields, and more reliable reserve calculations. Two activities continued this quarter as part of the geological and petrophysical characterization of the fluvial-deltaic Ferron Sandstone: (1) evaluation of the Ivie Creek and Willow Springs Wash case-study areas and (2) technology transfer.

  12. Geological and petrophysical characterization of the Ferron Sandstone for 3-D simulation of a fluvial-deltaic reservoir. Technical progress report, April 1--June 30, 1995

    SciTech Connect

    Allison, M.L.

    1995-07-28

    The objective of this project is to develop a comprehensive, interdisciplinary, and quantitative characterization of a fluvial-deltaic reservoir which will allow realistic inter-well and reservoir-scale modeling to be constructed for improved oil-field development in similar reservoirs world-wide. The geological and petrophysical properties of the Cretaceous Ferron Sandstone in east-central Utah will be quantitatively determined. Both new and existing data will be integrated into a three-dimensional representation of spatial variations in porosity, storativity, and tensorial rock permeability at a scale appropriate for inter-well to regional-scale reservoir simulation. Results could improve reservoir management through proper infill and extension drilling strategies, reduction of economic risks, increased recovery from existing oil fields, and more reliable reserve calculations. Technical progress this quarter is divided into regional stratigraphy, case studies, stochastic modeling and fluid-flow simulation, and technology transfer activities. The regional stratigraphy of the Ferron Sandstone outcrop belt from Last Chance Creek to Ferron Creek is being described and interpreted. Photomosaics and a database of existing surface and subsurface data are being used to determine the extent and depositional environment of each parasequence, and the nature of the contacts with adjacent rocks or flow units. For the second field season, detailed geological and petrophysical characterization of the primary reservoir lithofacies typically found in a fluvial-dominated deltaic reservoir, is continuing at selected case-study areas.

  13. [Evaluation of parameters of radionuclide transition from soil particles and plant components of the upper layer of turf to cow's milk under pasture conditions].

    PubMed

    Averin, V S; Kalinichenko, S A; Nenashev, R A; Tsurankov, E N

    2002-01-01

    An experiment was conducted on feeding lactating cows with soil and turf additives contaminated with both 137Cs and 90Sr of the Chernobyl origin. The radionuclides transfer coefficients (%) in the food chain were for soil additives: for 137Cs--0.02 +/- 0.006, for 90Sr--0.01 +/- 0.002; for turf additives: for 137Cs--0.02 +/- 0.005, for 90Sr--0.06 +/- 0.035. Regarding 90Sr, there is no significant tendency to higher transfer rate for the radionuclide from turf component compared to that for soil component. A contribution of soil component as well as turf component of soil was evaluated as an additional source of milk contamination while grazing cattle. It was concluded that the contribution is not pronounced at the remedial period after the accident (approximately 3% from total activity consumed with ration) and it can be rejected in cattle breeding practice. The results achieved can be used for prediction of radionuclides concentrations in milk produce in cattle breeding under industrial contamination of agricultural lands. PMID:12395781

  14. Effect of the cationic composition of sorption solution on the quantification of sorption-desorption parameters of heavy metals in soils.

    PubMed

    Sastre, J; Rauret, G; Vidal, M

    2006-03-01

    We obtained the sorption isotherms of Cd, Cu, Pb and Zn in clay, clay saline and organic soils. The distribution coefficients (K(d)) were determined in 0.02 eq l(-1) CaCl(2) and in a solution that simulated the soil solution cationic composition. The K(d) values greatly varied with the composition of the sorption solution and the initial metal concentration. The sorption experiments were complemented with the quantification of the extractable metal, to estimate the reversibility of metal sorption. The extraction yields depended on the metal-soil combination, and the initial metal concentration, showing no correlation with previous K(d) values. The effect of the solution composition in mobility predictions was estimated through a Retention Factor, defined as the ratio of the K(d) versus the extraction yield. Results showed that risk was over- or underestimated using the CaCl(2) medium in soils with a markedly different soil solution composition. PMID:16203070

  15. Silicon-mediated changes on some physiological and enzymatic parameters symptomatic of oxidative stress in barley grown in sodic-B toxic soil.

    PubMed

    Gunes, Aydin; Inal, Ali; Bagci, Esra G; Coban, Sencan

    2007-06-01

    The effect of silicon (Si) on the growth, sodium (Na), chloride (Cl), boron (B) concentrations, lipid peroxidation (MDA), membrane permeability (MP), lypoxygenase activity (LOX), proline (PRO) and H(2)O(2) accumulation, and the activities of major antioxidant enzymes (superoxide dismutase, SOD; catalase, CAT and ascorbate peroxidase, APX) of barley grown in original sodic-B toxic soil were investigated. Si applied to the sodic-B toxic soil at 70, 140 and 280 mg kg(-1) levels significantly increased Si concentrations of the plants and counteracted the deleterious effects of sodicity (Na ions) and B on shoot growth. Membrane permeability and the concentrations of H(2)O(2) and MDA increased, while PRO concentration decreased in plants grown in sodic-B toxic soil without Si. LOX activity was increased by applied Si. Compared with control plants, the activities of SOD and CAT were decreased, but APX was increased by applied Si levels. PMID:17070965

  16. Silicon-mediated changes on some physiological and enzymatic parameters symptomatic of oxidative stress in barley grown in sodic-B toxic soil.

    PubMed

    Gunes, Aydin; Inal, Ali; Bagci, Esra G; Coban, Sencan

    2007-06-01

    The effect of silicon (Si) on the growth, sodium (Na), chloride (Cl), boron (B) concentrations, lipid peroxidation (MDA), membrane permeability (MP), lypoxygenase activity (LOX), proline (PRO) and H(2)O(2) accumulation, and the activities of major antioxidant enzymes (superoxide dismutase, SOD; catalase, CAT and ascorbate peroxidase, APX) of barley grown in original sodic-B toxic soil were investigated. Si applied to the sodic-B toxic soil at 70, 140 and 280 mg kg(-1) levels significantly increased Si concentrations of the plants and counteracted the deleterious effects of sodicity (Na ions) and B on shoot growth. Membrane permeability and the concentrations of H(2)O(2) and MDA increased, while PRO concentration decreased in plants grown in sodic-B toxic soil without Si. LOX activity was increased by applied Si. Compared with control plants, the activities of SOD and CAT were decreased, but APX was increased by applied Si levels.

  17. Parameter Sets for Upper and Lower Bounds on SOIL-TO-INDOOR-AIR CONTAMINANT ATTENUATION PREDICTED BY THE JOHNSON AND ETTINGER VAPOR INTRUSION MODEL

    EPA Science Inventory

    Migration of volatile chemicals from the subsurface into overlying buildings is known as vapor intrusion (VI). Under certain circumstances, people living in homes above contaminated soil or ground water may be exposed to harmful levels of these vapors. A popular VI screening-le...

  18. Impact of biotic and a-biotic parameters on structure and function of microbial communities living on sclerotia of the soil-borne pathogenic fungus Rhizoctonia solani

    PubMed Central

    Zachow, Christin; Grosch, Rita; Berg, Gabriele

    2011-01-01

    The plant pathogen Rhizoctonia solani is very difficult to control due to its persistent, long-living sclerotial structures in soil. Sclerotia are the main source of infection for Rhizoctonia diseases, which cause high yield losses on a broad host range world-wide. Little is known about micro-organisms associated with sclerotia in soil. Therefore, microbial communities of greenhouse and field incubated Rhizoctonia sclerotia were analysed by a multiphasic approach. Using microbial fingerprints performed by PCR-SSCP, sclerotia-associated bacterial communities showed a high diversity, whereas only a few fungi could be detected. Statistical analysis of fingerprints revealed the influence of soil types, incubation conditions (greenhouse, field), and incubation time (5 and 12 weeks) on the bacterial as well as fungal community. No significant differences were found for the microbial community associated with different Rhizoctonia anastomosis sub-groups (AG 1-IB and AG 1-IC). Rhizoctonia sclerotia are an interesting bio-resource: high proportions of fungal cell-wall degrading isolates as well as those with antagonistic activity towards R. solani were found. While a fraction of 28.4% of sclerotia-associated bacteria (=40 isolates) with antagonistic properties was determined, only 4.4% (=6 isolates) of the fungal isolates were antagonistic. We identified strong antagonists of the genera Bacillus, Enterobacter, Pseudomonas, and Stenotrophomonas, which can be used as biological control agents incorporated in soil or applied to Rhizoctonia host plants. PMID:26109749

  19. Atrazine dissipation in s-Triazine-adapted and Non-adapted soil from Coloroado and Mississippi: Implications of enhanced degradation on atrazine fate and transport parameters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Modelers and regulatory agencies typically use default atrazine half-life values of 60 to 120 d to predict the herbicide’s transport; however, if atrazine persistence is reduced in soils exhibiting enhanced degradation, but modelers continue to use historic atrazine persistence estimates, then accur...

  20. Agronomic measures of P, Q/I parameters and lysimeter-collectable P in subsurface soil horizons of a long-term slurry experiment.

    PubMed

    Anderson, R; Xia, L

    2001-01-01

    Soils from a long-term slurry experiment established in 1970 at Hillsborough, Northern Ireland, were used in the experiment. The site has a clay loam soil overlying Silurian shale. Seven treatments were used with three replicate plots per treatment under the following manurial regimes: (1) mineral fertiliser supplying 200 kg N, 32 kg P and 160 kg K ha(-1) yr(-1); (2)-(4