Ordinary kriging and indicator kriging in the cartography of trace elements contamination in São Domingos mining site (Alentejo, Portugal)

To verify the feasibility of portable X-ray ﬂuorescence (PXRF) for rapidly analyzing, assessing and improving soil heavy metals mapping, 351 samples were collected from Fuyang District, Hangzhou City, in eastern China. Ordinary kriging (OK) and co-ordinary kriging (COK) combined with PXRF measurements were used to explore spatial patterns of heavy metals content in the soil. The Getis-Ord index was calculated to discern hot spots of heavy metals. Finally, multi-variable indicator kriging was conducted to obtain a map of multi-heavy metals pollution. The results indicated Cd is the primary pollution element in Fuyang, followed by As and Pb. Application of PXRF measurements as covariates in COK improved model accuracy, especially for Pb and Cd. Heavy metals pollution hot spots were mainly detected in northern Fuyang and plains along the Fuchun River in southern Fuyang because of mining, industrial and traffic activities, and irrigation with polluted water. Area with high risk of multi-heavy metals pollution mainly distributed in plain along the Fuchun River and the eastern Fuyang. These findings certified the feasibility of using PXRF as an efficient and reliable method for soil heavy metals pollution assessment and mapping, which could contribute to reduce the cost of surveys and pollution remediation.

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Review of the Kriging Technique Applications to Groundwater Quality

Journal of Engineering ◽

10.31026/j.eng.2021.12.03 ◽

2021 ◽

Vol 27 (12) ◽

pp. 23-32

Author(s):

Hayat Azawi ◽

May Samir Saleh

Keyword(s):

Groundwater Quality ◽

Quality Indicator ◽

Ordinary Kriging ◽

Indicator Kriging ◽

Disjunctive Kriging ◽

Kriging Method ◽

Lognormal Kriging ◽

Groundwater Contaminants ◽

Simple Kriging

Kriging, a geostatistical technique, has been used for many years to evaluate groundwater quality. The best estimation data for unsampled points were determined by using this method depending on measured variables for an area. The groundwater contaminants assessment worldwide was found through many kriging methods. The present paper shows a review of the most known methods of kriging that were used in estimating and mapping the groundwater quality. Indicator kriging, simple kriging, cokriging, ordinary kriging, disjunctive kriging and lognormal kriging are the most used techniques. In addition, the concept of the disjunctive kriging method was explained in this work to be easily understood.

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Environmental impact assessment of radionuclides and trace elements at the Kurday U mining site, Kazakhstan

Journal of Environmental Radioactivity ◽

10.1016/j.jenvrad.2012.05.001 ◽

2013 ◽

Vol 123 ◽

pp. 14-27 ◽

Cited By ~ 27

Author(s):

B. Salbu ◽

M. Burkitbaev ◽

G. Strømman ◽

I. Shishkov ◽

P. Kayukov ◽

...

Keyword(s):

Trace Elements ◽

Environmental Impact ◽

Impact Assessment ◽

Environmental Impact Assessment ◽

Mining Site

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Trace elements absorption by citrus in a heavily polluted mining site

Journal of Geochemical Exploration ◽

10.1016/j.gexplo.2011.11.005 ◽

2012 ◽

Vol 113 ◽

pp. 76-85 ◽

Cited By ~ 13

Author(s):

A. Romero ◽

I. González ◽

E. Galán

Keyword(s):

Trace Elements ◽

Mining Site

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Application of kriging techniques for assessing the salinity of irrigated soils: the case of El Ghrous perimeter, Biskra, Algeria

Spanish Journal of Soil Science ◽

10.3232/sjss.2019.v9.n2.04 ◽

2019 ◽

Vol 9 ◽

Author(s):

Mohamed Amine Abdennour ◽

Abdelkader Douaoui ◽

Abdelhamid Bradai ◽

Amel Bennacer ◽

Manuel Pulido Fernández

Keyword(s):

Soil Salinity ◽

Ordinary Kriging ◽

Indicator Kriging ◽

Spatial Trend ◽

Risk Areas ◽

Geostatistical Techniques ◽

Anthropogenic Processes ◽

Irrigated Perimeter ◽

Made In ◽

Irrigated Soils

In semi-arid and arid areas, soil salinity has adverse effects both on the environment and agricultural production. The main causes of this salinization come from natural or anthropogenic processes, which is certainly an environmental problem that affects more than 20% of the world's land. This study was made in order to map the spatial distribution of soil salinity of the irrigated perimeter of El Ghrous in southeastern Algeria. These maps were performed based on data collected from 190 soil samples from 0 to 15 cm deep. We used ordinary kriging (OK) to analyze the spatial variability of soil salinity, while indicator kriging (IK) was used to analyze salinity versus threshold values. The salinity map predicted by the electrical conductivity (EC) values using the ordinary kriging (OK) method showed the different classes of salinity according to Durand's classification with moderately saline 3rd order dominance, while the unsalted soil (EC < 0.6 dS m<sup>-1</sup>) represents a very low percentage (1.5%). The indicator kriging (IK) was carried out by four thresholds which correspond to the salinity class limits: EC > 0.6, EC > 1, EC > 2, EC > 3, and EC > 4 dS m<sup>-1</sup>, for developing probability maps to determine risk areas. This study has shown the spatial trend of soil salinity by geolocation of different classes, and to carry out risk maps using geostatistical techniques.

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Geostatistics as a tool to reduce the sampling effort in forest inventories

Scientia Agraria Paranaensis ◽

10.18188/sap.v20i2.25601 ◽

2021 ◽

pp. 174-179

Author(s):

Myrcia Minatti ◽

Carlos Roberto Sanquetta ◽

Sylvio Péllico Neto ◽

Ana Paula Dalla Corte ◽

Vinicius Costa Cysneiros

Keyword(s):

Forest Inventory ◽

Ordinary Kriging ◽

Simple Random Sampling ◽

Exponential Model ◽

Indicator Kriging ◽

Sampling Effort ◽

Thematic Maps ◽

Visual Interpretation ◽

Forest Inventories ◽

Geostatistical Techniques

Geostatistics is one of the tools applied to investigate the spatial variability of forests to reduce costs and recognize the best productivity areas for planning. This study aimed to test the performance of geostatistical techniques in reducing the sampling effort in forest inventories. For this purpose, we used the height of dominant trees as a discriminator of the homogeneous strata to obtain a better representation of the productivity within the forest stands. We carried out the study in Pinus taeda L. stands in the Center-South of Paraná, Brazil, by using plots from a forest inventory allocated with the systematic process. Then, we tested three models to determine the site curves (Schumacher, Chapman-Richards 2, and 3 coefficients) with the thirty-seventh year being the reference age. To model the spatial patterns of the dominant height, we used the ordinary kriging, and, after that, we generated the thematic maps of the site classes. Similarly, we used the indicator kriging which allowed obtaining the probabilities of high, medium, and low productivity sites. The processing of the stratified sampling, with the support of the visual interpretation of the images, allowed us to define five strata according to productivity. Results showed that ordinary kriging is effective in defining the productivity classes. Along with geostatistical techniques, it produces more homogeneous strata and reduces the errors of the forest inventory. Moreover, the best-selected model was the Chapman-Richards (3 coefficients) for the site curves. The exponential model was the best model to identify the best areas of the probability of occurrence of sites with higher productivity. The efficiency of indicative kriging generated thematic maps to delimit the likely locations of the most promising sites. Overall, geostatistics proved to be efficient concerning error when compared to simple random sampling.

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Mapping The Distribution of Iron Content in Nickel Laterite Deposits Using Indicator Kriging and Ordinary Kriging Interpolation Method

PROMINE ◽

10.33019/promine.v9i1.2316 ◽

2021 ◽

Vol 9 (1) ◽

pp. 29-36

Author(s):

Hendro Purnomo

Keyword(s):

Root Mean Square ◽

Iron Content ◽

Ordinary Kriging ◽

Interpolation Method ◽

Indicator Kriging ◽

Kriging Interpolation ◽

Mean Square ◽

Kriging Method ◽

Nickel Laterite ◽

Kriging Interpolation Method

Beside containing nickel (Ni), nickel laterite deposits also contain other elements, including iron (Fe) which have varying levels in each layer. In this study, the distribution of Fe content in the limonite layers was carried out using the indicator kriging method to analyze the probability distribution of iron levels and ordinary kriging to analyze the variability of iron levels spatially. Fitting the variogram was undertaken by using spherical, exponential and gaussian models. The selection of the best variogram model was carried out based on the smallest root mean square error (RMSE) value, while the estimation of resource potential was calculated by the polygon extended area method. The results of the interpolation show that the distribution of iron anomaly occupies ± 83,3% of the research area with a potential resource of ±64.522.110 ton of iron. The evaluation of the interpolation results base on the root mean square standardized prediction error (RMSP) indicates that the estimation results of iron content using the ordinary kriging method are underestimated.

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TRACE ELEMENTAL ANALYSIS OF PERMIAN GONDWANA COALS IN BANGLADESH BY PIXE TECHNIQUE

International Journal of PIXE ◽

10.1142/s0129083504000148 ◽

2004 ◽

Vol 14 (03n04) ◽

pp. 89-97 ◽

Cited By ~ 3

Author(s):

J. PODDER ◽

S. A. TAREK ◽

T. HOSSAIN

Keyword(s):

Trace Elements ◽

Coal Combustion ◽

Thermal Power ◽

Mining Site ◽

Trace Elemental Analysis ◽

X Ray ◽

Power Stations ◽

Thermal Power Stations ◽

Trace Elemental ◽

Northwestern Bangladesh

The study of trace elements level in coal arouses much interest in recent days to assess and evaluate the environmental impact related to its benefit and usage in applying it to the problem of mining site. Further, it is more important during the coal combustion in thermal power stations particularly in relation to the emission of air toxic, disposal and utilization of fly ash. The paper describes the level of nineteen environmentally significant trace elements found in recently discovered Permian Gondwana coals in Barapukuria and Khalaspir of Northwestern Bangladesh using Proton Induced X-ray Emission (PIXE) spectroscopy. Both the mineral species and trace elements are expected to be due to sedimentary and aerobic environmental condition where the Permian coals have been generated depending on their degree of evolution.

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A geostatistical approach to cork production sampling estimation in Quercus suber forests

Canadian Journal of Forest Research ◽

10.1139/x05-197 ◽

2005 ◽

Vol 35 (12) ◽

pp. 2787-2796 ◽

Cited By ~ 18

Author(s):

Fernando Montes ◽

María José Hernández ◽

Isabel Cañellas

Keyword(s):

Ordinary Kriging ◽

Measurement Errors ◽

Quercus Suber ◽

Indicator Kriging ◽

Surface Distribution ◽

Geostatistical Approach ◽

Cork Production ◽

Cork Thickness ◽

Productive Area ◽

Kriging Estimation

The estimation of cork production in cork oak (Quercus suber L.) forests is complex because of the high heterogeneity of stripped surface distribution (the variable used to quantify cork production) and the importance of cork thickness estimation as a determining factor of cork quality. In this study, the different sources of variation in stripped surface ([Formula: see text]d) estimation and the effects of the spatial structure of the variance were analysed. When indicator kriging was used to determine the cork productive area, ordinary kriging and kriging with measurement errors gave better estimations of [Formula: see text]d (ordinary block kriging estimation of 156.16 m2/ha and standard errors (SE) of 16.40 and 15.7 m2/ha, respectively) than the design-based approach for the whole forest area (66.37 m2/ha, SE = 11.34 m2/ha). The SE lying in the second-stage design was 4.93 m2/ha. The ordinary kriging prediction of cork thickness using an XY(λZ) variogram, where λ is the anisotropy coefficient of the Z axis, gives a smaller SE and less bias than the kriging prediction with the XY variogram (for a mean estimation of 21.91 mm, SE = 3.90 and 4.16 mm, respectively, and sum of errors of 0.42 and 0.85 respectively).

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