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Dust, as a source of trace metal elements, affects the health of society. The spatial and temporal concentrations of dust‐bound trace metals (Cd, Pb, Ni, Zn, Cu, and Mn) in Kuhdasht watershed (456 km2), Lorestan Province, Iran, is investigated. Dust is collected using glass traps placed in ten research stations in the region. The spatial and temporal distribution of dust trace metals are plotted using ARC‐GIS. The highest and the lowest concentrations of Zn (9751150 mg kg?1), Pb (46.352.9 mg kg?1), and Cd (2.443.30 mg kg?1) are obtained in winter, of Ni (98110 mg kg?1) and Cu in autumn (16.053.5 mg kg?1), and of Mn in summer (385505 mg kg?1). The spatial concentrations of dust‐bound trace metals indicate all, except Cu, show a decreasing trend from the mountains toward the plains, similar to that of soil and of dust, except for Zn, which shows higher concentrations in dust than in soil. The potential sources of dust‐bound trace metals and their rate of contamination are also investigated using the enrichment and contamination factors. The major sources of Cd and Zn in the dust of watershed are due to anthropogenic activities or from activities outside the borders.  相似文献   
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Pedodiversity and pedogenesis in Zayandeh-rud Valley, Central Iran   总被引:4,自引:0,他引:4  
A geomorphic hierarchical downscaling method was used to decompose the forms and processes forming the landscapes and their subdivisions in the main region of Zayandeh-rud Valley. The purpose of this study was to determine the degree of soil heterogeneity and to check if K-entropy would be a good measure of soil evolution. Soil diversity analyses were performed considering soil families as individuals of soil entities in each geomorphic or taxonomic category level. Pedodiversity indices were used to follow the trend of soil and landscape evolution. The relationships between K-entropy (Shannon diversity index) and pedo-richness versus increasing area were analyzed to find out the effects of soil–landscape evolution on complexity of soil patterns in different geomorphic surfaces. Entropy–age relationship was studied to check the pedogenetic pathways responsible for soil landscape evolution. The soil diversity increases as geomorphic and taxonomic hierarchy levels decrease. The diversity indices were high when the sequence of soil horizons in a homogeneous family was also investigated. An increase in K-entropy of soil and landscape during time confirms the hypothesis of soil divergence evolution, whereby differences in initial conditions or local perturbations, and dynamic instability appear to have produced more variable soils and landscapes in the study area.  相似文献   
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