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Niu C.,Jilin University | Wang Q.,Jilin University | Chen J.,Jilin University | Zhang W.,Jilin University | And 2 more authors.
Sustainability (Switzerland) | Year: 2015

The outbreak of debris flows in a reservoir region can affect the stability of hydropower stations and threaten the lives of the people living downstream of dams. Therefore, determining the hazard degree of debris flows in a reservoir region is of great importance. SPOT5 remote sensing images and digital elevation models are introduced to determine the characteristics of debris-flow catchments. The information is acquired through comprehensive manual investigation and satellite image interpretation. Ten factors that influence debris flow are extracted for the hazard assessment. The weight of these factors is determined using the analytic hierarchy process method. As a multi-criterion decision analysis method, fuzzy synthetic evaluation is applied for hazard assessment. © 2015 by the authors. Source

Wang T.,Jilin University | Wang H.,Jilin Institute of Geological Environment Monitoring | Zhang F.,Jilin University | Xu T.,Jilin University
Marine Pollution Bulletin | Year: 2013

The main purpose of this study focused on the feasibility of geologic CO2 sequestration within the actual geological conditions of the first Carbon Capture and Storage (CCS) project in China. This study investigated CO2-water-rock interactions under simulated hydrothermal conditions via physicochemical analyses and scanning electron microscopy (SEM). Mass loss measurement and SEM showed that corrosion of feldspars, silica, and clay minerals increased with increasing temperature. Corrosion of sandstone samples in the CO2-containing fluid showed a positive correlation with temperature. During reaction at 70°C, 85°C, and 100°C, gibbsite (an intermediate mineral product) formed on the sample surface. This demonstrated mineral capture of CO2 and supported the feasibility of geologic CO2 sequestration. Chemical analyses suggested a dissolution-reprecipitation mechanism underlying the CO2-water-rock interactions. The results of this study suggested that mineral dissolution, new mineral precipitation, and carbonic acid formation-dissociation are closely interrelated in CO2-water-rock interactions. © 2013 Elsevier Ltd. Source

Wang T.,Jilin University | Zhang F.,Jilin University | Wang H.,Jilin Institute of Geological Environment Monitoring | Liu Z.,Jilin University | Zhong S.,Jilin University
Journal of Food, Agriculture and Environment | Year: 2013

Fifty soil samples were collected from the Hun River Alluvial-plain Fan (HRAF) of Shenyang, Liaoning Province, China and analysed for various metals to determine the heavy metals spatial distribution. Cu, Pb, Zn, Ni and Cr were concentrated in the northwest and midwest HRAF, while the southeast portion was contaminated with As. The contamination coefficients (Ci f) were found to be in the order of As > Pb > Cu > Cr > Zn > Ni. The combined pollution index values indicated that most sampling sites were characterised by combined heavy metal pollution, and the most contaminated area was the middle of the HRAF. Potential ecological risk assessment of monomial heavy metal risk factors showed an Ei r < 40 and a potential ecological risk index < 50 for most sites, indicating low potential environmental risk. However, some sites in the middle of the HRAF indicated a moderate potential environmental risk. These results are important for the development of proper management strategies to decrease non-point source pollution by various remediation practices in Shenyang, China. Source

Niu C.-C.,Jilin University | Wang Q.,Jilin University | Chen J.-P.,Jilin University | Wang K.,Jilin Institute of Geological Environment Monitoring | And 2 more authors.
Quarterly Journal of Engineering Geology and Hydrogeology | Year: 2014

The Wudongde dam is located in the mountainous region of southwestern China. Debris flows form a serious threat to the safety of this site and appropriate hazard assessments need to be carried out. However, the results of such assessments may be erroneous, especially when certain influencing factors are not properly considered. In this study, a stepwise discriminant analysis is used to investigate which factors influence debris-flow occurrence. A total of 27 debris flows, identified through field investigation, are analysed and this resulted in the selection of 17 influence factors. By employing a stepwise discriminant analysis it is possible to reduce these to just five major influencing factors, thus simplifying the calculation of debris-flow hazard assessment. Extension theory has been used to further identify the role of the influencing factors in debris-flow hazard assessment. Thus, reasonable and objective results of hazard degree assessment are expected. Once the criteria for debris-flow hazard assessment are established, the hazard degree of each debris flow is determined. Of the 27 debris flows analysed in this study, four are categorized as 'extremely hazardous', 10 as 'very hazardous', 10 as 'moderately hazardous', and three as 'slightly hazardous'. The results are consistent with current expert knowledge of these debris flows, thereby providing an indication that the methods used in this study adequately replicate the expert assessments. © 2014 The Geological Society of London. Source

Li L.-J.,Jilin Institute of Geological Environment Monitoring | Ma L.,Jilin Institute of Geological Environment Monitoring | Zhang J.,Jilin Institute of Geological Environment Monitoring | Zhao Y.-N.,Jilin Institute of Geological Environment Monitoring | And 4 more authors.
Acta Geoscientica Sinica | Year: 2014

Songyuan is a new city of petrochemical industry base in northern China. The development of petrochemical industry has caused a certain degree of contamination of groundwater in the area. On the basis of regional hydrogeological investigation, the authors assessed present situation of groundwater contamination by using single factor evaluation and superposition index method and analyzed the influence of contamination on the groundwater. The concentrations of Fe, Mn and NH4+ in the groundwater are much higher than their standards, mainly associated with high background values of the original environment. Most areas of the city have been slightly polluted, and local seriously and relatively heavily polluted districts assume point or zonal distribution. The total hardness and mineralization degree of groundwater also seriously exceed the standard values. In local heavily polluted places, the concentrations of Cl, SO4 2-, NO3 -, COD and volatile phenol in the water also exceed the standard values. The groundwater pollution is closely related to the oil extraction, refining, processing and transportation in addition to human life pollution. Source

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