Potential catastrophic water outflow from Lake Dian, China: Possible hydrological and ecological risks

CATENA ◽  
2021 ◽  
Vol 207 ◽  
pp. 105589
Author(s):  
Han Wu ◽  
Hucai Zhang ◽  
Xiaonan Zhang ◽  
Wei Peng ◽  
Qi Liu ◽  
...  
Keyword(s):  
Ecological Risks ◽  
Water Outflow

p-EMA (II): evaluating ecological risks of pesticides for a farm-level risk assessment system

Agronomie ◽  
2003 ◽  
Vol 23 (1) ◽  
pp. 75-84 ◽  
Author(s):  
Andy Hart ◽  
Colin D. Brown ◽  
Kathy A. Lewis ◽  
John Tzilivakis
Keyword(s):  
Risk Assessment ◽  
Assessment System ◽  
Ecological Risks ◽  
Farm Level

The study of the process of evolution of the jet under outflow of water from the supercritical state through a thin nozzle

2016 ◽  
Vol 11 (1) ◽  
pp. 66-71 ◽  
Author(s):  
R.Kh. Bolotnova ◽  
V.A. Korobchinskaya
Keyword(s):  
Stationary Process ◽  
Supercritical State ◽  
System Of Differential Equations ◽  
Jet Formation ◽  
Cylindrical Coordinates ◽  
Initial Stage ◽  
Supersonic Regime ◽  
Water Outflow ◽  
Thin Nozzle ◽  
Supercritical Temperature

The dynamics of the water outflow from the initial supercritical state through a thin nozzle is studied. To describe the initial stage of non-stationary process outflow the system of differential equations of conservation of mass, momentum and energy in a two-dimensional cylindrical coordinates with axial symmetry is used. The spatial distribution of pressure and velocity of jet formation was received. It was established that a supersonic regime of outflow at supercritical temperature of 650 K is formed, which have a qualitative agreement for the velocity compared with the Bernoulli analytical solution and the experimental data.

Hong Kong University Students’ Normative Beliefs about Aggression toward Police during Social Protests 2019–2020: The Role of Ecological Risks and Future Orientation

2021 ◽  
pp. 001112872110141
Author(s):  
Jian-Bin Li ◽  
Catrin Finkenauer
Keyword(s):  
Hong Kong ◽  
University Students ◽  
Community Violence ◽  
Future Orientation ◽  
Ecological Risks ◽  
Normative Beliefs ◽  
Poor Family ◽  
Social Protests ◽  
Delinquent Peers

We examined the association between normative beliefs about aggression toward police (NBAGG→P) and participation in social protests during 2019–2020 and use of aggression among 1,025 Hong Kong university students. We also investigated the role of ecological risks (i.e., distrust in institutions, exposure to community violence, poor family monitoring, poor university discipline and affiliation with delinquent peers) and future orientation in NBAGG→P. The results showed that NBAGG→P was related to more participation in social protests and use of aggression. Ecological risks (except for poor family monitoring) and a positive future orientation were related to more and less NBAGG→P, respectively. Moreover, the “distrust in institutions and NBAGG→P” link was stronger for students with more, rather than less, positive future orientation.

scholarly journals Dilemma of mining: economic development and ecological risks

2020 ◽  
Vol 575 ◽  
pp. 012245
Author(s):  
Sukri ◽  
Ariana ◽  
Dian Ekawaty ◽  
Febriyanto Syam ◽  
Ahmad Amiruddin
Keyword(s):  
Economic Development ◽  
Ecological Risks

scholarly journals Biological Risk Assessment of Heavy Metals in Sediments and Health Risk Assessment in Marine Organisms from Daya Bay, China

2020 ◽  
Vol 9 (1) ◽  
pp. 17
Author(s):  
Zexing Kuang ◽  
Yangguang Gu ◽  
Yiyong Rao ◽  
Honghui Huang
Keyword(s):  
Heavy Metals ◽  
Risk Assessment ◽  
Marine Organisms ◽  
Daya Bay ◽  
Ecological Risks ◽  
The Monte Carlo Method ◽  
Accumulation Index ◽  
The Mean ◽  
Primary Pollutant ◽  
Geo Accumulation

The concentrations of heavy metals in sediments and marine organisms in Daya Bay were investigated, and the Monte Carlo method was used to analyze the uncertainty of the results of geo-accumulation characteristics and ecological and health risks. The mean concentrations of metal elements in sediments were in the following order: Zn > Cr > Cu > As > Cd > Hg, while those in marine organisms were Zn > Cu > As > Cr ≈ Cd > Hg. The geo-accumulation index (Igeo) indicated that the primary pollutant was Hg, with 5.46% moderately polluted, and 39.52% for unpolluted to moderately polluted. Potential ecological risks (RI) were between low and high risks, and the contributions of Hg, Cd, and As to ecological risks were 50.85%, 33.92%, and 11.47%, respectively. The total hazard coefficients (THQ) were less than 1, but on the basis of total carcinogenic risks (TCR), the probability of children and adults exceeded the unacceptable risk threshold of 22.27% and 11.19%, respectively. Sensitivity analysis results showed that the concentrations of carcinogenic elements contributed to risk in the order of As > Cd > Cr. Therefore, in order to effectively control heavy metals contamination in Daya Bay, it is necessary to strengthen the management of Hg, Cd, and As emissions.

scholarly journals Evaluating ecological risks and tracking potential factors influencing heavy metals in sediments in an urban river

2021 ◽  
Vol 33 (1) ◽  
Author(s):  
Dongping Liu ◽  
Jian Wang ◽  
Huibin Yu ◽  
Hongjie Gao ◽  
Weining Xu
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Ecological Risk ◽  
Metal Pollution ◽  
Heavy Metal Pollution ◽  
Risk Index ◽  
Urban River ◽  
Ecological Risks ◽  
Background Values ◽  
Potential Factors

Abstract Background Heavy metal pollution of aquatic systems is a global issue that has received considerable attention. Canonical correlation analysis (CCA), principal component analysis (PCA), and potential ecological risk index (PERI) have been applied to heavy metal data to trace potential factors, identify regional differences, and evaluate ecological risks. Sediment cores of 200 cm in depth were taken using a drilling platform at 10 sampling sites along the Xihe River, an urban river located in western Shenyang City, China. Then they were divided into 10 layers (20 cm each layer). The concentrations of the As, Cd, Cr, Cu, Hg, Ni, Pb and Zn were measured for each layer. Eight heavy metals, namely Pb, Zn, As, Cd, Cr, Cu, Ni, and Hg, were measured for each layer in this study. Results The average concentrations of the As, Cd, Cu, Hg, and Zn were significantly higher than their background values in soils in the region, and mainly gathered at 0–120 cm in depth in the upstream, 0–60 cm in the midstream, and 0–20 cm downstream. This indicated that these heavy metals were derived from the upstream areas where a large quantity of effluents from the wastewater treatment plants enter the river. Ni, Pb, and Cr were close or slightly higher than their background values. The decreasing order of the average concentration of Cd was upstream > midstream > downstream, so were Cr, Cu, Ni and Zn. The highest concentration of As was midstream, followed by upstream and then downstream, which was different to Cd. The potential factors of heavy metal pollution were Cd, Cu, Hg, Zn, and As, especially Cd and Hg with the high ecological risks. The ecological risk levels of all heavy metals were much higher in the upstream than the midstream and downstream. Conclusions Industrial discharge was the dominant source for eight heavy metals in the surveyed area, and rural domestic sewage has a stronger influence on the Hg pollution than industrial pollutants. These findings indicate that effective management strategies for sewage discharge should be developed to protect the environmental quality of urban rivers.

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