ارزيابي ريسك آلودگي خاك به فلزات سنگين در استان همدان

چكيده انگليسي :

Risk Assessment of Soil Pollution by Heavy Metals in Hamadan Province Elham Sadat Madani Email Address em iut@yahoo com 24 5 2011 Department of Natural Resources Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Persian Dr Alireza Soffianian Email Address Soffianian@cc iut ac ir AbstractThe management based methods to control heavy metals pollution need the quantitative informationabout heavy metals levels Moreover determination of hotspots could help to make a suitable decision Theanomaly delineation maps of heavy metal provide an integrated view of their position amount anddistribution These could be used by decision makers for data analysis defining the probable pollution sourceand planning a pollution control program The main purpose of this study was to determine spatialdistribution of As Sb Cr Cd Ni Co Cu Zn Pb Fe and V in the surface soils of Hamadan province createa holistic view to position level and anomaly of classified elements through Principal Component Analysis PCA False Color Composition FCC Inverse Overlay Method and Weighted Linear Composition WLC In this order 286 surface soil samples 0 20cm were collected using systematic random sampling and thetotal concentrations of heavy metals were measured The distribution maps of heavy metal concentrationswere generated by radial basis function ordinary and disjunctive Kriging The Kriging methods precision ofdifferent models was compared by Mean Absolute Error MAE and Mean Bias Error MBE and themethod with higher precision was selected to mapping the heavy metals concentrations in the soil Overlaying the heavy metals distribution maps with geology and land use maps showed that As Fe Cd Zn Cr Co Ni and Sb have geological origin Cu and V have originated from agriculture and geology Leadconcentration is controlled by geological formation agricultural activities and also urban pollution Theelements were combined in four classes As Zn Pb Co Fe V Cr Ni Cu and finally Sb and As by falsecolor composition method The first element layer obtained from FCC method was overlaid with the thirdlayer and second layer with fourth layer in an inverse manner Finally weighted linear composition was doneon fuzzy data of two element classes Result showed that the most suitable method for interpolation of As Zn V Pb Fe is disjunctive Kriging by exponential model and for Ni Co Cr Sb is ordinary Kriging byexponential model Cd and Cu were interpolated by radial basic method Based on principal componentanalysis the heavy metals situated in 4 factors The first component included Zn V Ni Cr Co As and Fe The second component contained Cu and Cd Pb was located in the third component As and Sb in the fourthcomponent Generally the high positive association in any component indicates a natural input of thesemetals from parental rocks and high negative association may reflect the anthropogenic contamination in thesurface soil Based on obtained maps by inverse overlay method and weighted linear composition theanomaly of the first group of elements was observed in the southeast of Malayer and west of Nahavand andAsad Abad The second component elements were maximums in Asad Abad the west of Kabudar Ahang andeast part of Malayer The majority of the study area in the first component elements had moderate to highcontamination risk and in the second component elements had low contamination risk The comparison methods showed that the weighted linear composition was the best method between the anomaly delineationaccording to precision accuracy and methodology However in the point view of interpretations of the results the false color composition method is more simple KeywordsKriging Heavy metals Principal Components Analysis False Color Composition Inverse Overlay Method Weighted Linear Composition

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ارزيابي ريسك آلودگي خاك به فلزات سنگين در استان همدان

كريجينگ , آناليز همبستگي , آناليز مولفه اصلي , تركيب رنگي , رويهم گذاري معكوس , تركيب خطي وزني