scholarly journals TOC and Black Carbon records in sediment of Lake Yangzong, Yunnan Province under the influence of human activities during the past century

2017 ◽  
Vol 29 (4) ◽  
pp. 1018-1028 ◽  
Author(s):  
LIU Yilan ◽  
◽  
ZHANG Enlou ◽  
LIU Enfeng ◽  
WANG Rong ◽  
...  
Keyword(s):  
Black Carbon ◽  
Human Activities ◽  
Yunnan Province ◽  
Past Century ◽  
The Past

Coastal dune mobility over the past century: A global review

2020 ◽  
Vol 44 (6) ◽  
pp. 814-836 ◽  
Author(s):  
Jinjuan Gao ◽  
David M Kennedy ◽  
Teresa M Konlechner
Keyword(s):  
Human Activities ◽  
Vegetation Cover ◽  
Dominant Role ◽  
Coastal Dunes ◽  
Mediterranean Area ◽  
Global Scale ◽  
Coastal Dune ◽  
Sediment Supply ◽  
Past Century ◽  
The Past

The mobility of coastal dunes is characterised by bio-geomorphological responses related to change in boundary conditions, particularly sediment supply, wind and vegetation cover, as well as human activities. There remains uncertainty regarding the relative importance of these drivers on dune mobility at a global scale. In this study, trends and dominant drivers of coastal dune mobility are synthesised through the literature review focusing on shifts in dune mobility over the last century (1870–2018). In total, 176 individual dunes, with 55 dunes from the Europe-Mediterranean area, 23 from Africa, 30 from North America, 23 from South America, 20 from Oceania and 23 from Asia, are reviewed in this work. The results show that there is a worldwide trend of dune stabilisation, with 93% (164 out of 176) of the reviewed sites showing a loss of bare sand area due to an increase in vegetation cover and urbanisation expansion. Multiple factors have contributed to the stabilisation process, including (a) land-use change such as the change of traditional farming practises, coastal urbanisation and tourism development; (b) dune stabilisation projects; (c) sediment decline caused by the riverine and coastal constructions; and (d) change in climate (i.e. the decrease in windiness, and the increase in temperature and rainfall) and storms. Our results suggest human intervention played a dominant role in altering dune mobility for most dunes during the past century, while climate and storms are also important drivers, especially for dune sites with limited human activities.

scholarly journals Human-Induced Enrichment of Potentially Toxic Elements in a Sediment Core of Lake Balkhash, the Largest Lake in Central Asia

2020 ◽  
Vol 12 (11) ◽  
pp. 4717 ◽  
Author(s):  
Kun Huang ◽  
Long Ma ◽  
Jilili Abuduwaili ◽  
Wen Liu ◽  
Gulnura Issanova ◽  
...  
Keyword(s):  
Central Asia ◽  
Sediment Core ◽  
Human Activities ◽  
Toxic Elements ◽  
Potentially Toxic Elements ◽  
Dominant Factor ◽  
Past Century ◽  
The Past ◽  
Lake Balkhash ◽  
The Impact

Over the past century, the impacts of human activities on the natural environment have continued to increase. Historic evolution of the environment under anthropogenic influences is an important reference for sustainable social development. Based on the geochemical analyses of a short sediment core of 49 cm from Lake Balkhash, the largest lake in Central Asia, potential factors historically influencing geochemical variation were revealed, and influences of human activity on regional environmental change were reconstructed over the past 150 years. The results showed that the dominant factor inducing changes in potentially toxic elements (V, Cr, Co, Ni, Zn, Cu, Cd, and Pb) is the physical weathering of the terrestrial materials. The variation in Ca content was influenced by the formation of authigenic carbonate. Since 1930, potentially toxic elements (Cr, Co, Ni, Zn, Cu, Cd, and Pb) in the lake sediments have obviously been affected by human activities, but the impact of human activities has not exceeded that of natural terrestrial weathering. In particular, the enrichment factors (EFs) for Cd and Pb reached 1.5. The average ecological risks of Cd were higher than the criterion of 30, suggesting a moderate risk to the local ecosystem in recent years. Total risk indices indicated moderate potential ecological risk for the lake ecology. The results will provide support for the environmental protection and better management practices of the Lake Balkhash watershed.

scholarly journals Centennial records of PAHs and black carbon in Altay mountain peatlands, Xinjiang, China

2021 ◽  
Author(s):  
Nana Luo ◽  
Kunshan Bao ◽  
Rui Yu ◽  
Xingtu Liu ◽  
Yelebolat Tuoliuhan ◽  
...  
Keyword(s):  
Black Carbon ◽  
Human Activities ◽  
Fossil Fuels ◽  
Biomass Combustion ◽  
Energy Structure ◽  
Past Century ◽  
Peat Core ◽  
Total Pahs ◽  
Polycyclic Aromatic ◽  
Regional Population

<p>Black carbon (BC) and polycyclic aromatic hydrocarbons (PAHs) are potentially proxies of changes in natural and human activities during the past century. It is important to identify historical BC sources and differentiate human activities contribution to BC in the environment. In this study, a 30 cm peat profile from the Jiadengyu (JDY) peatland in Altay Mountain was dated by the <sup>137</sup>Cs and <sup>210</sup>Pb methods. BC, total PAHs content and δ<sup>13</sup>C<sub>BC</sub> in JDY peat were tested. The results showed that the TOC, BC and PAHS contents in JDY peat core were 17.09 ~ 47.16%, 1.14 ~ 67.138 mg/g and 260.58 ~ 950.98 ng/g, respectively. The value of δ<sup>13</sup>C<sub>BC</sub> ranged -31.5‰ ~ -27.43‰, with an average of -30.52‰. The range of total PAHs concentrations in JDY peat core were between 260.59 ng/g and 950.98 ng/g. The BC was significantly correlated with PAHs and regional population. The BC fluxes have slightly increased since 1900s with the increasing population and cultivate area, and more significantly in 1980s.<strong> </strong>The burning of biomass and yak dung, fossil fuels, and human activities (mining, coking coal) may have important effects on the BC emission of soil in the Altay region. The change of BC and δ<sup>13</sup>C<sub>BC</sub> reflected the change of local energy structure. With the regional reclamation increasing and environment- friendly industry developing, the BC source of JDY peatland is mainly the result of the interaction between biomass combustion and fossil fuel combustion.</p>

Innovative Uses of Wave Power: Environmental Management of the Port of Ensenada, Mexico

2002 ◽  
Vol 36 (4) ◽  
pp. 74-84 ◽  
Author(s):  
Steven Czitrom ◽  
Ismael Núñez ◽  
Isabel Ramírez
Keyword(s):  
Environmental Management ◽  
Numerical Model ◽  
Water Column ◽  
Human Activities ◽  
Wave Power ◽  
Past Century ◽  
The Past ◽  
National University ◽  
Restrictive Measures ◽  
Shed Light

Over the past century, the water and sediments of the port of Ensenada, México, have accumulated a lot of pollution from human activities. Although present day restrictive measures inhibit any further accumulation, the existing aggregation in the sediments is sufficient to maintain high levels of contamination throughout the port, despite the flushing action of the tides. A SIBEO (SIBEO is an acronym for the Spanish SIstema de Bombeo por Energía de Oleaje) wave-driven seawater pump recently developed at the National University of Mexico is proposed to inject clean and oxygen rich seawater from outside the port to promote flushing in the more stagnant sections of the harbour. Results from a numerical model of the port hydrodynamics shed light on why the tides cannot on their own adequately flush the system, and how the wave-driven seawater pump will help to promote ventilation. Over the next 4 years, a cluster of SIBEO pumps is proposed to be installed on the Ensenada breakwater to inject unpolluted seawater at various locations in the port. A programme will be carried out to study the effects on the water column and sediments, in this first full-scale application of the SIBEO.

scholarly journals A 100-year record of climate change and human activities inferred from the geochemical composition of sediments in Chaiwopu Lake, arid northwest China

2016 ◽  
Author(s):  
Wen Liu ◽  
Jinglu Wu ◽  
Xiangliang Pan
Keyword(s):  
Climate Change ◽  
Human Activities ◽  
Chemical Weathering ◽  
Northwest China ◽  
Past Century ◽  
Surface Erosion ◽  
Geochemical Composition ◽  
The Past ◽  
Element Concentrations ◽  
Arid Northwest China

An 81-cm sediment core from Chaiwopu Lake in arid northwest China was analyzed for <sup>137</sup>Cs activity and concentrations of major and trace elements. We used these data to discriminate between the influence of climate change and human activities on the geochemical change of the lake sediments over the past century. Elements Al, K, Ba, Ti, V, Fe, Ni, Mn, Li, and Be were mainly from detrital. Ca, Sr, and Mg concentrations were controlled by chemical weathering processes. Na came mainly from salt precipitation caused by a decline in water level. Enrichment factors for Pb and P in recent deposits are large, indicating they were influenced by human activies. Geochemical conditions during the past century can be divided into three stages: i) From ca. 1900 to the1950s element concentrations varied widely and frequently. In general, concentrations of typical mobile elements Ca, Sr, and Mg stay relatively high whereas values for other elements remained relatively low. This was interpreted to reflect variable climate under conditions of weak surface erosion intensity. ii) From the 1950s to the early 2000s, element concentrations display less variability. The Al, K, Ba, Ti, P, Cr, V, Fe, Ni, Mn, Co, Cu, Li, Zn, Be, Pb, and Na contents were generally higher, whereas contents of Ca, Sr, and Mg were on average lower. This indicates that the regional environment was conducive to surface erosion. Enrichment of trace metals and major elements in the sediment reflects enhanced human activities. iii) In the last decade, Pb and P exhibited a great increase, possibly associated with the input from fossil fuel combustion, sewage discharge and non-point-source pollution in the watershed. The lake volume decreased substantially because of groundwater extraction for municipal water, which resulted in a marked increase in salinity and enhanced Na precipitation.

scholarly journals Lacustrine Records of Climatic Change and Human Activities in the Catchmentof Erhai Lake? Yunnan Province Since the Past 1800 Years

2000 ◽  
Vol 12 (4) ◽  
pp. 297-303 ◽  
Author(s):  
ZHANG Zhenke ◽  
◽  
WU Ruijin ◽  
SHEN Ji ◽  
WU Yanhong ◽  
...  
Keyword(s):  
Climatic Change ◽  
Human Activities ◽  
Yunnan Province ◽  
Erhai Lake ◽  
The Past

The zoonotic potential of bat-borne coronaviruses

2020 ◽  
Vol 4 (4) ◽  
pp. 365-381
Author(s):  
Ny Anjara Fifi Ravelomanantsoa ◽  
Sarah Guth ◽  
Angelo Andrianiaina ◽  
Santino Andry ◽  
Anecia Gentles ◽  
...  
Keyword(s):  
Genetic Material ◽  
Field Research ◽  
Sympatric Species ◽  
Animal Origin ◽  
Mammalian Host ◽  
Past Century ◽  
The Past ◽  
Novel Host ◽  
Horseshoe Bat ◽  
Human Infections

Seven zoonoses — human infections of animal origin — have emerged from the Coronaviridae family in the past century, including three viruses responsible for significant human mortality (SARS-CoV, MERS-CoV, and SARS-CoV-2) in the past twenty years alone. These three viruses, in addition to two older CoV zoonoses (HCoV-229E and HCoV-NL63) are believed to be originally derived from wild bat reservoir species. We review the molecular biology of the bat-derived Alpha- and Betacoronavirus genera, highlighting features that contribute to their potential for cross-species emergence, including the use of well-conserved mammalian host cell machinery for cell entry and a unique capacity for adaptation to novel host environments after host switching. The adaptive capacity of coronaviruses largely results from their large genomes, which reduce the risk of deleterious mutational errors and facilitate range-expanding recombination events by offering heightened redundancy in essential genetic material. Large CoV genomes are made possible by the unique proofreading capacity encoded for their RNA-dependent polymerase. We find that bat-borne SARS-related coronaviruses in the subgenus Sarbecovirus, the source clade for SARS-CoV and SARS-CoV-2, present a particularly poignant pandemic threat, due to the extraordinary viral genetic diversity represented among several sympatric species of their horseshoe bat hosts. To date, Sarbecovirus surveillance has been almost entirely restricted to China. More vigorous field research efforts tracking the circulation of Sarbecoviruses specifically and Betacoronaviruses more generally is needed across a broader global range if we are to avoid future repeats of the COVID-19 pandemic.

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