scholarly journals Geostatistical Approach for Groundwater Quality Evaluation in Zarin Abad Plain, Iran

2019 ◽  
Author(s):  
Abdollah Taheri Tizro ◽  
Mohamad Mohamadi
Keyword(s):  
Spatial Variability ◽  
Groundwater Quality ◽  
Kriging Model ◽  
Quality Parameters ◽  
General Nature ◽  
Data Generation ◽  
Geophysical Investigation ◽  
Study Region ◽  
Geostatistical Methods ◽  
Geostatistical Approach

Background and Purpose: This study was undertaken, first, to investigate the hydrogeological setting of the study area and geophysical data, second to examine the general nature of the groundwater quality. In this regard, ordinary Kriging, Co-Kriging, and Inverse Weighted Distance (IWD) strategies were applied to develop spatial variability maps, and study the fluctuations in groundwater quality parameters in Zarin Abad plain, Zanjan Province, Iran in 2017-2018. Materials and methods: To inquire the groundwater quality parameters, samples were provided from 61 shallow and deeply drilled observed wells in Zarin Abad Goltapeh plain. The studies were carried out by using geostatistical methods to find out the most applicable method, which can be used to develop spatial variability maps in order to study the changes in groundwater quality parameters (Na+, K+, Ca2+, Mg2+, SO42-, HCO3-, Cl- and EC).  The local geophysical, geological, and hydrogeological surveys were precisely accomplished to specify the architecture of various subsurface geological horizons. In addition, a geophysical investigation with a Schlumberger configuration was performed in the study region for the purpose of field data generation. Results: Based on key results, the values of electrical conductivity (EC) were recorded within the range of 480 and 6580 μS/cm. The order of major cations and anions were Na+>Ca2+>Mg2+ and SO42->Cl->HCO3-, respectively. It is worthwhile mentioning that groundwater salinity was found to be dependent upon factors, such as water long residence time and minerals dissolution. Conclusion: To assess the spatial distribution in groundwater parameters, the variable mode was used. The results obtained from Kriging, Co-Kriging, and IDW methods were then evaluated by the error indices of RMSE and MAE. Co-Kriging Model was the most optimal approach in studying the spatial variation of groundwater quality parameters.

scholarly journals Spatial variability of selected physicochemical parameters within peat deposits in small valley mire: a geostatistical approach

Geologos ◽  
2014 ◽  
Vol 20 (4) ◽  
pp. 269-288 ◽  
Author(s):  
Dominik Pawłowski ◽  
Daniel Okupny ◽  
Wojciech Włodarski ◽  
Tomasz Zieliński
Keyword(s):  
Spatial Variability ◽  
Sequential Gaussian Simulation ◽  
Mineral Matter ◽  
Geostatistical Methods ◽  
Peat Deposits ◽  
Geostatistical Approach ◽  
Through Flow ◽  
Input Sample ◽  
Gaussian Simulation ◽  
Small Valley

Abstract Geostatistical methods for 2D and 3D modelling spatial variability of selected physicochemical properties of biogenic sediments were applied to a small valley mire in order to identify the processes that lead to the formation of various types of peat. A sequential Gaussian simulation was performed to reproduce the statistical distribution of the input data (pH and organic matter) and their semivariances, as well as to honouring of data values, yielding more ‘realistic’ models that show microscale spatial variability, despite the fact that the input sample cores were sparsely distributed in the X-Y space of the study area. The stratigraphy of peat deposits in the Ldzań mire shows a record of long-term evolution of water conditions, which is associated with the variability in water supply over time. Ldzań is a fen (a rheotrophic mire) with a through-flow of groundwater. Additionally, the vicinity of the Grabia River is marked by seasonal inundations of the southwest part of the mire and increased participation of mineral matter in the peat. In turn, the upper peat layers of some of the central part of Ldzań mire are rather spongy, and these peat-forming phytocoenoses probably formed during permanent waterlogging.

scholarly journals Assessment of groundwater quality in Bhavani region

2020 ◽  
Author(s):  
PERUMAL KARTHIKEYAN ◽  
Jabar Abdul Bari ◽  
Vennila G
Keyword(s):  
Spatial Distribution ◽  
Groundwater Quality ◽  
Quality Parameters ◽  
Weighted Interpolation ◽  
Distance Method ◽  
Study Region ◽  
Physico Chemical ◽  
Groundwater Samples ◽  
Inverse Distance ◽  
Spatial Distribution Map

This work deals with the spatial distribution of groundwater quality parameters and their interrelationship in Bhavani Taluk, Erode District, Tami Nadu, India. The present study deals with the suitability of groundwater quality for drinking purpose in Bhavani Taluk, Erode District, India and to determine the spatial distribution groundwater quality parameters by using ArcGIS. The groundwater samples of 53 wells from the study region are collected and are tested in the laboratory to determine the physico-chemical parameters and the obtained results determined the suitability of groundwater for drinking purposes by comparing with WHO standards. From the result, groundwater quality zones were identified as Good (423.10 sq.km), Moderate (155.70 sq.km) and Poor zones (63.18 sq.km) by inverse distance method weighted interpolation techniques from the spatial distribution map using ArcGIS. The study indicates that about half of the groundwater is not suitable for drinking due to by the excessive usage of fertilizers and necessary treatment has to be undertaken before drinking water supply.

scholarly journals Geostatistical methods in evaluating spatial variability of groundwater quality in Al-Kharj Region, Saudi Arabia

2017 ◽  
Vol 7 (7) ◽  
pp. 4013-4023 ◽  
Author(s):  
Abdulrasoul M. Al-Omran ◽  
Anwar A. Aly ◽  
Mohammad I. Al-Wabel ◽  
Mohammad S. Al-Shayaa ◽  
Abdulazeam S. Sallam ◽  
...  
Keyword(s):  
Saudi Arabia ◽  
Spatial Variability ◽  
Groundwater Quality ◽  
Geostatistical Methods

scholarly journals GEOSTATISTICAL APPROACH FOR THE ESTIMATION OF SHEAR-HOSTED GOLD DEPOSIT: A CASE STUDY OF THE OBUASI GOLD DEPOSIT, GHANA

2020 ◽  
Vol 5 (2) ◽  
pp. 76-84
Author(s):  
Casmed Charles Amadu ◽  
Gordon Foli ◽  
Bernard Kissi Abrokwa ◽  
Sylvester Akpah
Keyword(s):  
Spatial Variability ◽  
Gold Deposit ◽  
Extreme Values ◽  
Underground Mining ◽  
Parametric Method ◽  
Weighted Average ◽  
Indicator Kriging ◽  
Low Grade ◽  
Geostatistical Methods ◽  
Geostatistical Approach

Underground mining at Obuasi in Ghana has been in operation since 1947. This paper uses geostatistical methods to evaluate gold ore blocks to ensure reliable grades for mining large tonnage and low-grade resources. Historically, the principal ores were low tonnage, high grade and relatively homogeneous quartz stockwork with simple geometry and average bulk grades in the range of 20-30 g/t that were evaluated using conventional polygonal methods and mined by semi-mechanized means. Currently, the ore is a shear-hosted mixed quartz vein and disseminated sulphide type deposit of low grade that is mined using highly mechanized means. The need therefore arises for a re-assessment of the estimation procedures to ensure prolonged and more profitable mining. Both diamond drill (DD) core and stope/cross-cut channel samples were taken from Block 1 at the mine for analyses and re-assessment. A wireframe model was used to constrain the three dimensional (3D) block model of the deposit. Ordinary kriging (OK) and multiple indicator kriging (MIK) geostatistical methods were used to estimate gold grades. Grade distribution is positively skewed with high spatial variability and extreme values while background values are established as <0.6 g/t. The Spatial variability is characterized by fitting models on experimental variograms. The MIK approach mitigates the effects of outliers and establish grades that are consistently lower than the OK and the weighted average method that are widely used at the mine. The MIK method, a non-linear, non-parametric method of local grade estimation are applicable to the deposit architecture. Profoundly, the MIK method is a more reliable approach considering the fact that the MCF based on the estimates at the mine are high despite operational deficiencies on the mine. The results from this study demonstrates usefulness of geostatistics to determine the architecture of Au mineralization at the deposit scale.

Statistical analysis and physicochemical characteristics of groundwater ‎quality parameters: a case study

2021 ◽  
pp. 1-22
Author(s):  
Yaqoob Iqbal Memon ◽  
Sundus Saeed Qureshi ◽  
Imdad Ali Kandhar ◽  
Naeem Ahmed Qureshi ◽  
Sumbul Saeed ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Groundwater Quality ◽  
Physicochemical Characteristics ◽  
Quality Parameters

scholarly journals Evaluating the groundwater quality of Damodar Fan Delta (India) using fuzzy-AHP MCDM technique

2021 ◽  
Vol 11 (7) ◽  
Author(s):  
Sadik Mahammad ◽  
Aznarul Islam
Keyword(s):  
Water Quality ◽  
Groundwater Quality ◽  
Fuzzy Ahp ◽  
Poor Quality ◽  
Quality Parameters ◽  
Analytic Hierarchy ◽  
Fan Delta ◽  
Quality Water ◽  
Calcium Magnesium ◽  
Groundwater Quantity

AbstractIn recent years, groundwater pollution has become increasingly a serious environmental problem throughout the world due to increasing dependency on it for various purposes. The Damodar Fan Delta is one of the agriculture-dominated areas in West Bengal especially for rice cultivation and it has a serious constraint regarding groundwater quantity and quality. The present study aims to evaluate the groundwater quality parameters and spatial variation of groundwater quality index (GWQI) for 2019 using the fuzzy analytic hierarchy process (FAHP) method. The 12 water quality parameters such as pH, TDS, iron (Fe−) and fluoride (F−), major anions (SO42−, Cl−, NO3−, and HCO3−), and cations (Na+, Ca2+, Mg2+, and K+) for the 29 sample wells of the study area were used for constructing the GWQI. This study used the FAHP method to define the weights of the different parameters for the GWQI. The results reveal that the bicarbonate content of 51% of sample wells exceeds the acceptable limit of drinking water, which is maximum in the study area. Furthermore, higher concentrations of TDS, pH, fluoride, chloride, calcium, magnesium, and sodium are found in few locations while nitrate and sulfate contents of all sample wells fall under the acceptable limits. The result shows that 13.79% of the samples are excellent, 68.97% of the samples are very good, 13.79% of the samples are poor, and 3.45% of the samples are very poor for drinking purposes. Moreover, it is observed that very poor quality water samples are located in the eastern part and the poor water wells are located in the northwestern and eastern part while excellent water quality wells are located in the western and central part of the study area. The understanding of the groundwater quality can help the policymakers for the proper management of water resources in the study area.

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.

scholarly journals Interpolation of groundwater quality parameters with some values below the detection limit

2011 ◽  
Vol 15 (9) ◽  
pp. 2763-2775 ◽  
Author(s):  
A. Bárdossy
Keyword(s):  
Detection Limit ◽  
Maximum Likelihood ◽  
Groundwater Quality ◽  
Likelihood Estimation ◽  
Quality Parameters ◽  
Indicator Kriging ◽  
West Germany ◽  
Marginal Distributions ◽  
Copula Models ◽  
Measuring Device

Abstract. For many environmental variables, measurements cannot deliver exact observation values as their concentration is below the sensitivity of the measuring device (detection limit). These observations provide useful information but cannot be treated in the same manner as the other measurements. In this paper a methodology for the spatial interpolation of these values is described. The method is based on spatial copulas. Here two copula models – the Gaussian and a non-Gaussian v-copula are used. First a mixed maximum likelihood approach is used to estimate the marginal distributions of the parameters. After removal of the marginal distributions the next step is the maximum likelihood estimation of the parameters of the spatial dependence including taking those values below the detection limit into account. Interpolation using copulas yields full conditional distributions for the unobserved sites and can be used to estimate confidence intervals, and provides a good basis for spatial simulation. The methodology is demonstrated on three different groundwater quality parameters, i.e. arsenic, chloride and deethylatrazin, measured at more than 2000 locations in South-West Germany. The chloride values are artificially censored at different levels in order to evaluate the procedures on a complete dataset by progressive decimation. Interpolation results are evaluated using a cross validation approach. The method is compared with ordinary kriging and indicator kriging. The uncertainty measures of the different approaches are also compared.

scholarly journals Entropy weight application for calculating groundwater quality index (EWQI) in groundwater quality zoning in Pleistocene aquifer in the Phu My town, Ba Ria – Vung Tau province

2020 ◽  
Vol 4 (1) ◽  
pp. 140-148
Author(s):  
Nguyen Hai Au ◽  
Tran Minh Bao ◽  
Pham Thi Tuyet Nhi ◽  
Tat Hong Minh Vy ◽  
Truong Tan Hien ◽  
...  
Keyword(s):  
Water Quality ◽  
Groundwater Quality ◽  
Quality Index ◽  
Animal Husbandry ◽  
Quality Parameters ◽  
Entropy Weight ◽  
Groundwater Quality Index ◽  
Pleistocene Aquifer ◽  
Groundwater Samples ◽  
Entropy Weight Method

Groundwater in Phu My town is exploited essentially in Pleistocene aquifer and, used for many purposes like irrigation, domestic, production and animal husbandry. In this study, Groundwater Quality Index (EWQI) is calculated with Entropy weight method to determine the suitability of groundwater quality in study area. This method demonstrates the objectivity of each parameter calculated based on the degree of variability of each value and depends on the sample data source. The groundwater samples were collected from 17 wells in dry and wet seasons in 2017 with ten water quality parameters (pH, TDS, TH, Cl-, F-, NH4+-N, NO3--N, SO42-, Pb và Fe2+) were selected for analysising. The analysis results indicate groundwater quality is divided into 4 categories in this study area. In particular, over 70% of wells are "very good" water quality in both dry and wet seasons. Only 6% of wells are " water unsuitable for drinking purpose" of the total number of mornitoring wells in the study area.

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