نتایج جستجو برای: anthropogenic factor

تعداد نتایج: 867506  

2015
Jun Ren Zhen Shang Ling Tao Xia Wang

The concentrations of heavy metals in 21 samples collected from surface sediments from the Qinghai section of the Yellow were investigated in order to evaluate their distribution and pollution levels. The total concentrations showed wide variations with Cu 11.86~57.02 mg/kg, Fe 17236.67~41340.00 mg/kg, Mn 431.93~877.27 mg/kg, Ni 14.58~86.11 mg/kg, Zn 67.18~149.00 mg/kg, Cr 87.84~169.70 mg/kg, P...

2013

The climate system is warming, and a key factor in this change of the climate system is the increase of atmospheric concentrations of greenhouse gasses, which alter the balance of incoming and outgoing energy at the surface (Solomon et al., 2007). The most important anthropogenic greenhouse gas is carbon dioxide (CO2) and the uptake of carbon by the biosphere is a substantial component affectin...

Objective: Metal concentrations in 53 soil samples of Shahr-e-Babak were determined.  Methods: Assessment of enrichment factor and geo-accumulation index revealed higher degree of contamination of Cd, Pb, and Cu in soil samples. Moreover, results of metal fractionation study revealed high amount of Cd and Pb are associated in weakly bounds may lead to environmental risk of these metals.  Result...

زیرجانی‌زاده, صدیقه ,

Recently Gonabad, south of Khorasan Razavi Province,  in eastern Iran is affected by dust storm phenomena. To determine the physical and chemical characteristics of dust particles and their role in environmental pollution, 9 samples were collected for XRF, XRD, SEM and  EDX micro analysis. XRD analysis showed that most of mineralogical composition comprise tectosilicates (quartz and alkali feld...

Journal: :Environmental management 2009
Casey D Allen

Characterized by expensive housing, high socioeconomic status, and topographic relief, Upper Sonoran Lifestyle communities are found primarily along the Wildland-Urban Interface (WUI) in the Phoenix, Arizona metro area. Communities like these sprawl into the wildlands in the United States Southwest, creating a distinct urban fringe. This article, through locational comparison, introduces and ev...

2018
Xueru Guo Rui Zuo Li Meng Jinsheng Wang Yanguo Teng Xin Liu Minhua Chen

Globally, groundwater resources are being deteriorated by rapid social development. Thus, there is an urgent need to assess the combined impacts of natural and enhanced anthropogenic sources on groundwater chemistry. The aim of this study was to identify seasonal characteristics and spatial variations in anthropogenic and natural effects, to improve the understanding of major hydrogeochemical p...

2007
A. L. Steiner R. C. Cohen R. A. Harley S. Tonse D. B. Millet G. W. Schade A. H. Goldstein

Volatile organic compound (VOC) reactivity in central California is examined using a photochemical air quality model (the Community Multiscale Air Quality model; CMAQ) and ground-based measurements to evaluate the contribution of VOC to photochemical activity. We classify VOC into four categories: anthropogenic, biogenic, aldehyde, and other oxygenated VOC. Anthropogenic and biogenic VOC consis...

2013
Loghman Khoda Krami Fazel Amiri Alireza Sefiyanian Abdul Rashid B. Mohamed Shariff Tayebeh Tabatabaie Biswajeet Pradhan

One hundred and thirty composite soil samples were collected from Hamedan county, Iran to characterize the spatial distribution and trace the sources of heavy metals including As, Cd, Co, Cr, Cu, Ni, Pb, V, Zn, and Fe. The multivariate gap statistical analysis was used; for interrelation of spatial patterns of pollution, the disjunctive kriging and geoenrichment factor (EF(G)) techniques were a...

2013
Katie Hossler James E. Bauer

[1] Riverine exports of carbon (C) and organic matter (OM) are regulated by a variety of natural and anthropogenic factors. Understanding the relationships between these various factors and C and OM exports can help to constrain global C budgets and allow assessment of current and future anthropogenic impacts on both riverine and global C cycles. We quantified the effects of multiple natural an...

2009
Mukesh Kumar Christopher J. Duffy

0022-1694/$ see front matter 2009 Elsevier B.V. A doi:10.1016/j.jhydrol.2009.03.039 * Corresponding author. Fax: +814 863 7304. E-mail address: [email protected] (C.J. Duffy). It is generally accepted that the seasonal cycle of precipitation and temperature in cordillera of the western US exhibits a north–south pattern for annual, interannual and decadal time scales related to largescale climate pa...

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