Evaluation of Tailings from a Porphyry Copper Mine based on Joint Simulation of Contaminants     

Sohrabian  Babak  Hosseinzadeh Gharehgheshlagh  Hojjat  Soltani-Mohammadi  Saeed  Abdollahi Sharif  Jafar 《Natural Resources Research》2020,29(2):983-1005

Natural Resources Research - Tailings from porphyry copper mines contain environmentally harmful amounts of elements such as copper, molybdenum, lead and cobalt. Geostatistical simulation of...  相似文献   

Prediction of copper content in waste dump of Sarcheshmeh copper mine using visible and near-infrared reflectance spectroscopy     

Khosravi  Vahid  Ardejani  Faramarz Doulati  Aryafar  Ahmad  Yousefi  Saeed  Karami  Shawgar 《Environmental Earth Sciences》2020,79(7):1-16

The pore structure characteristics of soil are closely related to soil engineering properties. For saline soil distributed in seasonally frozen areas, existing studies have focused on the influence of freeze–thaw cycles on pore structure, while the influence of soluble salt in the soil is not well understood. This study aims to explore the influence of salt content and salt type on the pore structure of freeze-thawed soil. Soil samples with different salt contents (0–2%) and types (bicarbonate salt and sulfate salt) were subjected to 10 freeze–thaw tests, and their pore size distributions (PSDs) were obtained by mercury intrusion porosimetry tests. In addition, the PSDs were quantitatively analyzed by fractal theory. For both salts, the PSDs of the tested soil samples were bimodal after the freeze–thaw cycles, and the porosity of saline soil samples increased with increasing salt content overall. However, the contents of various types of pores in soil samples with two salt types were quite different. The variation in bicarbonate salt content mainly affected the mesopore and macropore contents in the soil samples, and their change trends were opposite to each other. For soil samples with sulfate salt, the porosity and macropore content increased significantly when the salt content exceeded 1%. In addition, the pore structures in saline soil presented fractal characteristics after the freeze–thaw cycles, and the fractal dimension was positively correlated with macropore content. This study may provide references for understanding the engineering properties of saline soil in seasonally frozen areas at the microscale.  相似文献   

Identification of trends in hydrological and climatic variables in Urmia Lake basin,Iran   总被引：1，自引：0，他引：1  

Farshad Fathian  Saeed Morid  Ercan Kahya 《Theoretical and Applied Climatology》2015,119(3-4):443-464

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Burden prediction in blasting operation using rock geomechanical properties     

Mohammad Rezaei  Masoud Monjezi  Saeed Ghorbani Moghaddam  Farhad Farzaneh 《Arabian Journal of Geosciences》2011,5(5):1031-1037

Burden prediction is a vital task in the production blasting. Both the excessive and insufficient burden can significantly affect the result of blasting operation. The burden which is determined by empirical models is often inaccurate and needs to be adjusted experimentally. In this paper, an attempt was made to develop an artificial neural network (ANN) in order to predict burden in the blasting operation of the Mouteh gold mine, using considering geomechanical properties of rocks as input parameters. As such here, network inputs consist of blastability index (BI), rock quality designation (RQD), unconfined compressive strength (UCS), density, and cohesive strength. To make a database (including 95 datasets), rock samples are used from Iran’s Mouteh goldmine. Trying various types of the networks, a neural network, with architecture 5-15-10-1, was found to be optimum. Superiority of ANN over regression model is proved by calculating. To compare the performance of the ANN modeling with that of multivariable regression analysis (MVRA), mean absolute error (E _a), mean relative error (E _r), and determination coefficient (R ²) between predicted and real values were calculated for both the models. It was observed that the ANN prediction capability is better than that of MVRA. The absolute and relative errors for the ANN model were calculated 0.05 m and 3.85%, respectively, whereas for the regression analysis, these errors were computed 0.11 m and 5.63%, respectively. Moreover, determination coefficient of the ANN model and MVRA were determined 0.987 and 0.924, respectively. Further, a sensitivity analysis shows that while BI and RQD were recognized as the most sensitive and effective parameters, cohesive strength is considered as the least sensitive input parameters on the ANN model output effective on the proposed (burden).  相似文献   

Determination of Realistic and Statistical Value of the Information Gathered from Exploratory Drilling     

Saeed Soltani  Ardeshir Hezarkhani 《Natural Resources Research》2011,20(4):207-216

Unlike other branches of geosciences, exploratory drilling has not been investigated within the framework of an information system; so, the expression “value of exploratory drilling information” (despite its common usage) is vague. This article presents a model for the evaluation of value of the information gathered from exploratory drilling after studying different mineral exploration and exploratory drilling systems within the framework of an “information system.” Although this model does not present the economic value of information, it is a suitable tool for comparing different drilling patterns. The model was verified on the basis of drilling data for the Gol-Gohar XIIA anomaly.  相似文献   

SHRIMP zircon U–Pb and biotite and hornblende Ar–Ar geochronology of Sungun,Haftcheshmeh, Kighal,and Niaz porphyry Cu–Mo systems: evidence for an early Miocene porphyry-style mineralization in northwest Iran     

Shohreh Hassanpour  Saeed Alirezaei  David Selby  Sergey Sergeev 《International Journal of Earth Sciences》2015,104(1):45-59

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Probabilistic rainfall thresholds for flood forecasting: evaluating different methodologies for modelling rainfall spatial correlation (or dependence)   总被引：2，自引：0，他引：2  

Saeed Golian  Bahram Saghafian  Mohammad Elmi  Reza Maknoon 《水文研究》2011,25(13):2046-2055

Rainfall threshold (RT) method is one of the evolving flood forecasting approaches. When the cumulative rainfall depth for a given initial soil moisture condition intersects the threshold rainfall curve, the peak discharge is expected to be equal or greater than the threshold discharge for flooding at the target site. Besides the total rainfall depth, spatial and temporal distribution of rainfall impacts the flood peak discharge and the time to peak. To revisit a previous study conducted by the authors, in which spatially independent rainfall pattern was assumed, the spatial distribution of rainfall was simulated following a Monte Carlo approach. The structure of the spatial dependence among sub‐watersheds' rainfalls was taken into account under three different scenarios, namely independent, bivariate copula (2copula) and multivariate Gaussian copula (MGC). For each set of generated random dimensionless rainfalls, the probabilistic RT curves were derived for dry moisture condition. Results were evaluated with both historical and simulated events. For the simulated events, threshold curves were assessed by means of categorical statistics, such as hit rate, false rate and critical success index (CSI). Results revealed that the best performance based on the CSI criterion corresponded to 50% curve in 2copula and MGC scenarios as well as 90% curve in the independent scenario. The recognition of 50% curve in 2copula and MGC scenarios is in agreement with our expectations that the mean probable curve should have the best performance. Moreover, the proposed inclusion of spatially dependent rainfall scenario improved the performance of RT curves by about 25% in comparison with the presumed spatially uniform rainfall scenario. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

Pesticides Removal Using Conventional and Low‐Cost Adsorbents: A Review     

Javad Zolgharnein  Ali Shahmoradi  Jahanbakhsh Ghasemi 《洁净——土壤、空气、水》2011,39(12):1105-1119

Worldwide pesticide usage has increased dramatically during the last three decades, coinciding with changing practices and increasing by intensive agriculture. This widespread use of pesticides for agricultural and non‐agricultural purposes has resulted in the presence of their residues in various environmental matrices. The occurrence of pesticides and their metabolite transported in rivers, channels, lakes, sea, air, soils, groundwater, and even drinking water, proves the high risk of these chemicals to human health and the environment. Therefore, pesticide removal is of an increasing concern. In this study, a review of the published literature dealing with pesticides removal process is presented. Firstly, pesticide removal by conventional means is briefly considered. Secondly, the use of the low‐cost sorbent through biosorption process is discussed comprehensively. The effect of factors such as pH, contact time, sorbent dosage, initial pesticide concentration, and optimization of biosorption conditions is also discussed. Kinetic, thermodynamic, and mechanism studies are also given. This study shows that both microorganisms and other materials with biological origin like agricultural by‐products may be used to this end. There is a significant potential for pesticide uptake by the use of various pristine and especially modified biosorbents. In the case of living organisms used as removal agents, degradation may also play a role in the total removal observed.  相似文献   

A novel approach for ports’ container terminals’ risk management based on formal safety assessment: FAHP-entropy measure—VIKOR model     

Khorram  Saeed 《Natural Hazards》2020,103(2):1671-1707

Natural Hazards - Maritime transport, which requires complex, large, and long port systems, is a major system in the world trade, and since such systems face different risks, various methods have...  相似文献   

Application of different clustering approaches to hydroclimatological catchment regionalization in mountainous regions,a case study in Utah State     

Elnaz Sharghi  Vahid Nourani  Saeed Soleimani  Fahreddin Sadikoglu 《山地科学学报》2018,15(3):461-484

With respect to the different hydrological responses of catchments, even the adjacent ones, in mountainous regions, there are a great number of motivations for classifying them into homogeneous clusters. These motivations include prediction in ungauged basins (PUB), model parameterization, understanding the potential impact of environmental changes, transferring information from gauged catchments to the ungauged ones. The present study investigated the similarity of catchments through the hydro-climatological pure time-series of a 14-year period from 2001 to 2015. Data sets encompass more than 13,000 month-station streamflow, rainfall, and temperature data obtained from 27 catchments in Utah State as one of the eight mountainous states of the USA. The identification, analysis, and interpretation of homogeneous catchments were investigated by applying the four approaches of clustering, K-means, Ward, and SOM (Self-Organized Map) and a newly proposed Wavelet-Entropy-based (WE-SOM) clustering method. By using two clustering evaluation criteria, 3, 5, and 6 clusters were determined as the best numbers of clusters, depending on the method employed, where each cluster represents different hydro-climatological behaviors. Despite the absence of geographic characteristics in input data matrix, the results indicated a regionalization in agreement with topographic characteristics. Considering the dependency of the hydrological behavior of catchments on the physiographic field aspects and characteristics, WE-SOM method demonstrated a more acceptable performance, compared to the other three conventional clustering methods, by providing more clusters. WE-SOM appears to be a promising approach in catchment clustering. It preserves the topological structure of data which can, as a result, be proofed in a greater number of clusters by dividing data into higher numbers of distinct clusters with similar altitudes of catchments in each cluster. The results showed the aptitude of wavelets to quantify the time-based variability of temperature, rainfall and streamflow, in the way contributing to the regionalization of diverse catchments.  相似文献