scholarly journals Some aspects about the spatial dependence index for variability of soil attributes

2018 ◽  
Vol 48 (6) ◽  
Author(s):  
Eduardo Lucas Ensslin dos Santos ◽  
Enio Júnior Seidel ◽  
Juliano de Bastos Pazini ◽  
Marcelo Silva de Oliveira ◽  
Edemar Appel Neto ◽  
...  
Keyword(s):  
Spatial Variability ◽  
Spatial Dependence ◽  
Vertical Direction ◽  
Real Data ◽  
Positive Behavior ◽  
Horizontal Direction ◽  
Soil Types ◽  
Soil Layers ◽  
Soil Attributes ◽  
Relationship Of

ABSTRACT: The main purpose of this article was to evaluate the behavior and relationship of the range and components of SDI (Spatial Dependence Index) in general and in function of field factors such as soil types, type of attribute and soil layers. This evaluation was based on real data collected in national journals. It was noticed that the parameter range, in general and for different field factors, presented asymmetric positive behavior. The components of the SDI showed approximately symmetrical behavior. The SDI can capture the range behavior more intensely (the spatial variability behavior in the horizontal direction of the semivariogram), and, in a less intense way, the behavior of the contribution and sill parameters (the spatial dependence behavior in the vertical direction of the semivariogram). Thus, the SDI describes the behavior of spatial dependence of the total set of aspects of the semivariogram.

scholarly journals GPS receivers for georeferencing of spatial variability of soil attributes

2011 ◽  
Vol 31 (6) ◽  
pp. 1162-1169 ◽  
Author(s):  
David L Rosalen ◽  
Marcos S Rodrigues ◽  
Carlos A Chioderoli ◽  
Flavia J. C Brandão ◽  
Diego S Siqueira
Keyword(s):  
Spatial Variability ◽  
Precision Agriculture ◽  
Agricultural Practices ◽  
Gps Receiver ◽  
Usual Practice ◽  
Soil Attributes ◽  
Structure Relationship ◽  
Kinematic Relative Positioning ◽  
Relationship Of

The characterization of the spatial variability of soil attributes is essential to support agricultural practices in a sustainable manner. The use of geostatistics to characterize spatial variability of these attributes, such as soil resistance to penetration (RP) and gravimetric soil moisture (GM) is now usual practice in precision agriculture. The result of geostatistical analysis is dependent on the sample density and other factors according to the georeferencing methodology used. Thus, this study aimed to compare two methods of georeferencing to characterize the spatial variability of RP and GM as well as the spatial correlation of these variables. Sampling grid of 60 points spaced 20 m was used. For RP measurements, an electronic penetrometer was used and to determine the GM, a Dutch auger (0.0-0.1 m depth) was used. The samples were georeferenced using a GPS navigation receiver, Simple Point Positioning (SPP) with navigation GPS receiver, and Semi-Kinematic Relative Positioning (SKRP) with an L1 geodetic GPS receiver. The results indicated that the georeferencing conducted by PPS did not affect the characterization of spatial variability of RP or GM, neither the spatial structure relationship of these attributes.

scholarly journals Suscetibilidade magnética na caracterização da variabilidade espacial de atributos do solo em solos subtropicais

2021 ◽  
Vol 43 ◽  
pp. e47
Author(s):  
Priscila Vogelei Ramos ◽  
Ricardo Simão Diniz Dalmolin ◽  
Jean Michel Moura-Bueno ◽  
José Marques Junior ◽  
Diego Silva Siqueira ◽  
...  
Keyword(s):  
Spatial Variability ◽  
Spatial Variation ◽  
Spatial Dependence ◽  
Clay Soil ◽  
Pearson Correlation ◽  
Soil Attributes ◽  
Variability Pattern ◽  
Sample Density ◽  
Basaltic Soils ◽  
Future Work

Magnetic susceptibility (MS) has been used to estimate soil attributes. With the proposal to increase the information of soils in southern Brazil the objectives of this work were: (i) evaluate the correlation of SM with soil attributes in a slope of subtropical basaltic soils; (ii) to characterize the spatial variation structure of MS and the content of sand, clay and COS; and (iii) identify the sample density that captures the spatial variability to assist future work under similar conditions. In a 22 ha area located in Santo Augusto - RS, Brazil, an 87 points sample grid was collected to determine soil attributes. Samples were also collected in five profiles along the slope. The profile data were analyzed by correlation to verify the degree of Pearson correlation of the SM with the attributes of the soil. In the sample grid spatial dependence analyzes were performed to assess the degree of spatial dependence on soil attributes. The MS presented a high correlation with the attributes of clay soil, Fes, Fed and COS. The evaluation of the spatial variation structure showed that the attributes presented a degree of spatial dependence ranging from weak for COS to strong for MS. The spatial variability pattern suggests a sample density of one point every 4 to 12 ha.

scholarly journals Resolving and Analyzing Landfast Ice Deformation by InSAR Technology Combined with Sentinel-1A Ascending and Descending Orbits Data

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6561
Author(s):  
Zhiyong Wang ◽  
Jian Liu ◽  
Jinning Wang ◽  
Lihua Wang ◽  
Meng Luo ◽  
...  
Keyword(s):  
Vertical Direction ◽  
Horizontal Direction ◽  
The Baltic Sea ◽  
Maximum Deformation ◽  
Landfast Ice ◽  
Fast Ice ◽  
The Baltic ◽  
Geometric Relationship ◽  
Relationship Of ◽  
Vertical Deformations

Detailed mapping of landfast ice deformation can be used to characterize the rheological behavior of landfast ice effectively and to improve sea ice modeling subsequently. In order to analyze the characteristics, trends and causes of deformation comprehensively and accurately, the Sentinel-1A ascending and descending orbits data were used to detect the horizontal and vertical deformation of the fast ice in the Baltic Sea. Firstly, the fast ice edge lines were acquired through feature extraction with interferometric coherence images and SAR amplitude images. Then, the deformation transformed model was constructed according to the geometric relationship of multi-orbits deformation measurements. Finally, the landfast ice deformations were resolved and the horizontal and vertical deformations were obtained. The results showed that the maximum deformation was—44 cm in horizontal direction and 16 cm in vertical direction within the fast ice region of 960 km2 during the time from 2 to 16 February 2018. The southwest wind was the principal reason for the deformation, which made the deformation mainly occur in the horizontal direction from east to west. Moreover, the inner fast ice kept stable due to the protection of outer consolidated ice. The results showed that the deformation trend and characteristics can be better understood by using InSAR technology that was combined with multi-orbits SAR data to resolve and analyze the landfast ice deformation.

LACTOSE-FERMENTING BACTERIA FROM THE INTESTINAL CONTENTS OF MARINE FISH

1933 ◽  
Vol 8 (1) ◽  
pp. 291-300 ◽  
Author(s):  
NORMAN E. GIBBONS
Keyword(s):  
Marine Fish ◽  
Marine Fishes ◽  
Soil Types ◽  
Intestinal Contents ◽  
Fermenting Bacteria ◽  
Relationship Of ◽  
The Relationship ◽  
Contaminated Waters

From 112 marine fishes examined for the presence of lactose-fermenting bacteria, 31 strains were isolated which produced acid and gas in this sugar and 3 which produced acid only.Ten strains belonged to the genus Aerobacter, 8 being Aer. aerogenes and 2 probably varieties of Aer. cloacae. Nine were soil types and the relationship of one was doubtful.Of 24 Escherichia types, 8 were faecal mammalian strains and one was doubtful. These belonged to the species Esch. coli, Esch. communior, Esch. grünthali and Bact. immobilis. One was found in a haddock taken 3 miles offshore; the others were found in fish taken in contaminated waters or near shore.Esch. coli, Esch. communior and Aer. aerogenes are not normal inhabitants of the intestinal tracts of marine fish.

scholarly journals Spatial variability and mapping of soil fertility status in a high-potential smallholder farming area under sub-humid conditions in Zimbabwe

2021 ◽  
Vol 3 (4) ◽  
Author(s):  
Gabriel Soropa ◽  
Olton M. Mbisva ◽  
Justice Nyamangara ◽  
Ermson Z. Nyakatawa ◽  
Newton Nyapwere ◽  
...  
Keyword(s):  
Spatial Variability ◽  
Soil Properties ◽  
Soil Ph ◽  
Strong Evidence ◽  
Spatial Dependence ◽  
Random Component ◽  
Smallholder Farming ◽  
Mineral N ◽  
Spatial Trend ◽  
Spatial Trends

AbstractA study was conducted to examine spatial variability of soil properties related to fertility in maize fields across varying soil types in ward 10 of Hurungwe district, Zimbabwe; a smallholder farming area with sub-humid conditions and high yield potential. Purposively collected and geo-referenced soil samples were analyzed for texture, pH, soil organic carbon (OC), mineral N, bicarbonate P, and exchangeable K. Linear mixed model was used to analyze spatial variation of the data. The model allowed prediction of soil properties at unsampled sites by the empirical best linear unbiased predictor (EBLUP). Evidence for spatial dependence in the random component of the model was evaluated by calculating Akaike’s information criterion. Soil pH ranged from 4.0 to 6.9 and showed a strong spatial trend increasing from north to south, strong evidence for a difference between the home and outfields with homefields significantly higher and between soil textural classes with the sand clay loam fraction generally higher. Soil OC ranged from 0.2 to 2.02% and showed no spatial trend, but there was strong evidence for a difference between home and outfields, with mean soil OC in homefields significantly larger, and between soil textural classes, with soil OC largest in the sandy clay loams. Both soil pH and OC showed evidence for spatial dependence in the random effect, providing a basis for spatial prediction by the EBLUP, which was presented as a map. There were significant spatial trends in mineral N, available P and exchangeable K, all increasing from north to south; significant differences between homefields and outfields (larger concentrations in homefields), and differences between the soil textural classes with larger concentrations in the sandy clay loams. However, there was no evidence for spatial dependence in the random component, so no attempt was made to map these variables. These results show how management (home fields vs outfields), basic soil properties (texture) and other factors emerging as spatial trends influence key soil properties that determine soil fertility in these conditions. This implies that the best management practices may vary spatially, and that site-specific management is a desirable goal in conditions such as those which apply in Ward 10 of Hurungwe district in Zimbabwe.

Van rechtvaardigheid naar uitputting en bevlogenheid

2012 ◽  
Vol 25 (2) ◽  
Author(s):  
Peter Verboon ◽  
Klaas Schakel ◽  
Karen van Dam
Keyword(s):  
Organizational Justice ◽  
Affective Commitment ◽  
Positive Behavior ◽  
Mediating Role ◽  
Two Samples ◽  
Group Engagement ◽  
Relationship Of ◽  
The Relationship ◽  
Moderating Role

From justice to exhaustion and engagement. The role of affective commitment to the organization From justice to exhaustion and engagement. The role of affective commitment to the organization In two studies the relationship between perceived organizational justice and emotional exhaustion and engagement was studied. Especially, the role of affective commitment to the organization in this relationship was examined. According to the group engagement model of Tyler and Blader (2003), procedural justice will result in positive behavior and attitudes because it increases commitment to the organization, thus implying that affective commitment mediates the relationship of justice with exhaustion and engagement. Conversely, Glazer and Kruse (2008) argue that a strong commitment to the organization can mitigate the effect of stressors, like injustice perceptions, on exhaustion and engagement, implying a moderating effect of commitment. These models were tested in two samples with employees working in a police organization. Both studies supported the mediating role of commitment; no evidence was found for a moderating role of commitment. The implication of these outcomes and the limitations of the study are discussed.

Effect of Savanna windrow wood burning on the spatial variability of soil properties

2021 ◽  
Vol 51 ◽  
Author(s):  
Diogo Neia Eberhardt ◽  
Robélio Leandro Marchão ◽  
Pedro Rodolfo Siqueira Vendrame ◽  
Marc Corbeels ◽  
Osvaldo Guedes Filho ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Spatial Variability ◽  
Spatial Dependence ◽  
Chemical Properties ◽  
Spatial Arrangement ◽  
Nugget Effect ◽  
Tropical Savannas ◽  
Geostatistical Methods ◽  
Exchangeable Ca ◽  
Spherical Models

ABSTRACT Tropical Savannas cover an area of approximately 1.9 billion hectares around the word and are subject to regular fires every 1 to 4 years. This study aimed to evaluate the influence of burning windrow wood from Cerrado (Brazilian Savanna) deforestation on the spatial variability of soil chemical properties, in the field. The data were analysed by using geostatistical methods. The semivariograms for pH(H2O), pH(CaCl2), Ca, Mg and K were calculated according to spherical models, whereas the phosphorus showed a nugget effect. The cross semi-variograms showed correlations between pH(H2O) and pH(CaCl2) with other variables with spatial dependence (exchangeable Ca and Mg and available K). The spatial variability maps for the pH(H2O), pH(CaCl2), Ca, Mg and K concentrations also showed similar patterns of spatial variability, indicating that burning the vegetation after deforestation caused a well-defined spatial arrangement. Even after 20 years of use with agriculture, the spatial distribution of pH(H2O), pH(CaCl2), Ca, Mg and available K was affected by the wood windrow burning that took place during the initial deforestation.

Numerical Simulation of a Jumper Conveying Slurry for Deep-Sea Mining

2021 ◽  
Author(s):  
Marcio Yamamoto ◽  
Tomo Fujiwara ◽  
Joji Yamamoto ◽  
Sotaro Masanobu
Keyword(s):  
Experimental Data ◽  
Pressure Drop ◽  
Dynamic Analysis ◽  
Internal Pressure ◽  
Deep Sea ◽  
Petroleum Industry ◽  
Vertical Direction ◽  
Internal Flow ◽  
Horizontal Direction ◽  
Viscous Pressure

Abstract One key technology for Deep-Sea Mining is the riser system. The riser is already a field-proven technology in the Petroleum Industry. However, several differences exist between a petroleum production riser and a riser for Deep-Sea Mining, mainly related to the internal flow. The ore-slurry has a larger density than the hydrocarbons and shall be pumped with a much higher flowrate. The current software tools for riser’s dynamic analysis may include the internal fluid hydrostatic pressure and the centrifugal and Coriolis forces imposed by the bent pipe’s internal flow. However, the internal pressure drop is not calculated. The internal pressure alters the pipe’s effective tension and can alter the pipe’s bending moment changing its mechanical behavior. This article describes a computational script’s development to run embedded in a commercial software for riser’s dynamic analysis. Our script calculates the internal viscous pressure drop along with the jumper. This pressure is then converted into wall axial tension (buckling) and imposed on each node of the jumper’s numerical model. Each simulation case was calculated twice with and without the internal flow viscous pressure drop. The comparison with experimental data revealed that the jumper’s average position has a good agreement among all cases. However, the amplitude caused by the top oscillation showed some discrepancies. Experimental data has the highest amplitude in the horizontal direction, while the simulation without viscous pressure calculation had the smallest. The simulation with our embedded script had intermediary amplitude in the horizontal direction. The vertical direction amplitudes have the same behavior for all cases, but the experimental data showed the highest amplitude.

scholarly journals Magnetic susceptibility for characterizing areas with different potentials for sugarcane production

2016 ◽  
Vol 51 (9) ◽  
pp. 1349-1358 ◽  
Author(s):  
Diego Silva Siqueira ◽  
José Marques Júnior ◽  
Daniel De Bortoli Teixeira ◽  
Sammy Sidney Rocha Matias ◽  
Livia Arantes Camargo ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
Spatial Variability ◽  
Exchange Capacity ◽  
Strongly Correlated ◽  
Soil Attributes ◽  
Sugarcane Production ◽  
Sugarcane Yield ◽  
Chemical Attributes ◽  
Physical And Chemical ◽  
Variability Model

Abstract The objective of this work was to evaluate the use of magnetic susceptibility for characterizing the spatial variability of soil attributes and identifying areas with different potentials for sugarcane (Saccharum spp.) production. Samples were collected at 110 points (1 per 7 ha) in the layers of 0.00-0.20 and 0.20-0.40 m, to determine the magnetic susceptibility and physical and chemical attributes of the soil. Fiber content, sucrose polarization (POL), and sugarcane yield were determined in 33 points. The spatial variability model for magnetic susceptibility was 63 and 22% more accurate in delimiting soil potential for sugarcane production than soil physical and chemical attributes at the 0.0-0.2 and 0.2-0.4-m layers, respectively. The spatial variability map for magnetic susceptibility was strongly correlated with clay (0.83 and 0.89, respectively, for the layers) and sand contents (-0.84 and -0.88); moderately correlated with organic matter (-0.25 and -0.35), sum of bases (-0.46 and 0.37), cation exchange capacity (0.22 and 0.47), pH (-0.52 and 0.13), and POL (0.43 and 0.53); and weakly correlated with sugarcane yield (0.26 and 0.23). Magnetic susceptibility can be used to characterize the spatial variability of soil attributes and to identify areas with different potentials for sugarcane production.

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