نتایج جستجو برای: anthropogenic factor

تعداد نتایج: 867506  

Journal: :desert 2012
m.s. ziaei r. masoudi m. ghodsi h. khosravi

desertification is more related to social and anthropogenic issues than natural causes and it becomes moreimportant over the time. human effects on desertification could be classified as direct and indirect factors. this studyhas focused on the effect of management factor, as a dominant case, on desertification of kashan region based onimdpa (imdpa: iranian model of desertification for potentia...

Journal: :journal of agricultural science and technology 2015
h. ghorbani n. hafezi moghads h. kashi

soil contamination significantly reduces environmental quality and affects human health. to investigate and assess the effects of land use on the concentrations of some heavy metals in surface soils of golestan province, 227 soil samples (0-60 cm) were collected from three types of land uses including agricultural lands, natural, and industrial areas. the total metals and metalloids (cr, se, as...

Journal: :iranian journal of science and technology (sciences) 2014
a. shakeri

concentrations of elements (as, co, cu, ni, mo, pb, v, cd, cr and zn) are studied in the surface sediments of bakhtegan lake, northwest of nyriz city, iran, to assess metal contamination. the average abundance order of trace elements content in bakhtegan lake sediments is cr>ni> v> zn> cu> co> as> pb> mo>cd. the comparison of trace elements concentration in bakhtegan lake sediments with toxicol...

Journal: :desert 0
m.s. ziaei associate professor, faculty of management, univ. of tehran, tehran, iran r. masoudi ph.d. student, faculty of natural resources, university of tehran, karaj, iran m. ghodsi ph.d. student, faculty of geography, university of tehran, tehran, iran h. khosravi ph.d. graduate, faculty of natural resources, university of tehran, karaj, iran

desertification is more related to social and anthropogenic issues than natural causes and it becomes moreimportant over the time. human effects on desertification could be classified as direct and indirect factors. this studyhas focused on the effect of management factor, as a dominant case, on desertification of kashan region based onimdpa (imdpa: iranian model of desertification for potentia...

2017
Nobuhiro Moteki Kouji Adachi Sho Ohata Atsushi Yoshida Tomoo Harigaya Makoto Koike Yutaka Kondo

Combustion-induced carbonaceous aerosols, particularly black carbon (BC) and brown carbon (BrC), have been largely considered as the only significant anthropogenic contributors to shortwave atmospheric heating. Natural iron oxide (FeOx) has been recognized as an important contributor, but the potential contribution of anthropogenic FeOx is unknown. In this study, we quantify the abundance of Fe...

2009
Jed O. Kaplan Kristen M. Krumhardt Niklaus Zimmermann

Humans have transformed Europe’s landscapes since the establishment of the first agricultural societies in the mid-Holocene. The most important anthropogenic alteration of the natural environment was the clearing of forests to establish cropland and pasture, and the exploitation of forests for fuel wood and construction materials. While the archaeological and paleoecological record documents th...

2011
Amanda M. Sparkman Lisette P. Waits Dennis L. Murray

Whether anthropogenic mortality is additive or compensatory to natural mortality in animal populations has long been a question of theoretical and practical importance. Theoretically, under density-dependent conditions populations compensate for anthropogenic mortality through decreases in natural mortality and/or increases in productivity, but recent studies of large carnivores suggest that an...

Journal: :The Science of the total environment 2014
N Walraven B J H van Os G Th Klaver J J Middelburg G R Davies

In this study the origin, behaviour and fate of anthropogenic Pb in sandy roadside soils were assessed by measuring soil characteristics, Pb isotope composition and content. In 1991 and 2003 samples were taken at different depth intervals at approximately 8 and 75 m from two highways in The Netherlands. The Pb isotope composition of the litter layer ((206)Pb/(207)Pb=1.12-1.14) differs from the ...

Journal: :Chemosphere 2006
Habes Ghrefat Nigem Yusuf

Thirty five bottom sediment samples were collected in a grid pattern from Wadi Al-Arab Dam. The present study focuses on the levels of Mn, Fe, Cu, Zn, Cd, total organic matter (TOM) and carbonate content (CO(3)(-2)) in order to assess the extent of environmental pollution and to discuss the origin of these contaminants in sediments of the dam. Concentration data were processed using correlation...

2016
Rafał Tyszka Anna Pietranik Jakub Kierczak Vojtěch Ettler Martin Mihaljevič Agnieszka Medyńska-Juraszek

Surroundings of the Legnica Cu smelter (Poland) offer insight into the behavior of Pb and other metal(oid)s in heavily contaminated soils in a relatively simple site, where lithogenic and anthropogenic Pb contributions have uniform Pb isotope composition over the time of smelter activity. Distribution of metal(oid)s decreases asymptotically with depth and below 30 cm reaches concentrations typi...

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