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Yang S.,Beijing Normal University | Yin G.,Beijing Normal University | Shi X.,National Marine Hazard Mitigation Service | Liu H.,Beijing Transportation Information Center | Zou Y.,Beijing Municipal Commission of Transport
International Journal of Disaster Risk Science | Year: 2016

Cities are centers of socioeconomic activities, and transport networks carry cargoes and passengers from one city to another. However, transport networks are influenced by meteorological hazards, such as rainstorms, hurricanes, and fog. Adverse weather impacts can easily spread over a network. Existing models evaluating such impacts usually neglect the transdisciplinary nature of approaches for dealing with this problem. In this article, a mesoscopic mathematical model is proposed to quantitatively assess the adverse impact of rainstorms on a regional transport network in northern China by measuring the reduction in traffic volume. The model considers four factors: direct and secondary impacts of rainstorms, interdependency between network components, and recovery abilities of cities. We selected the Beijing-Tianjin-Hebei region as the case study area to verify our model. Socioeconomic, precipitation, and traffic volume data in this area were used for model calibration and validation. The case study highlights the potential of the proposed model for rapid disaster loss assessment and risk reduction planning. © 2016, The Author(s).


Wang D.,CAS Qingdao Institute of Oceanology | Wu S.,CAS Qingdao Institute of Oceanology | Qin Z.,National Marine Hazard Mitigation Service | Spence G.,University of Victoria | Lu F.,Petrochina
Marine Geology | Year: 2013

Mass transport deposits (MTDs) occur in the South China Sea region, within the Qiongdongnan Basin, north of Guangle Uplift and west of Xisha Uplift. The MTDs (termed the Huaguang MTDs) are widely distributed in the late Miocene sedimentary strata, which belong to the upper Huangliu Formation (8.2-5.5Ma). Their general flow direction is from south to north. As a large-scale buried MTD system, it covers an area of more than 18,000km2. The system must be closely related to regional tectonic events, climate change, and variations in sedimentation rate. The dominant period when the Huaguang MTDs developed corresponds to the phase when the Red River Shear Zone reversed from left- to right-lateral slip. This event may have a close relationship with local uplift of Indochina, volcanism, and fault activation or re-activation within the surrounding area. Later in the Miocene, the accelerated onshore denudation and offshore basin subsidence of eastern Vietnam, and development of a mountainous river system, led to filling of the Yinggehai Basin and rapid accumulation of sediment which formed the regional steep bathymetry and weak cementation within the sediments. The sediment characteristics provide the critical conditions for forming MTDs. Polygonal faults within the MTDs and underlying strata show that fluid leakage took place following deposition of the MTDs. We suggest that the dominant trigger mechanism for large-scale MTDs was the activation or re-activation of major faults and associated volcanism in the late Miocene. © 2013 Elsevier B.V.


Zhang Y.,National Marine Hazard Mitigation Service | Zhang Y.,University of Notre Dame | Kennedy A.B.,University of Notre Dame | Tomiczek T.,University of Notre Dame | And 2 more authors.
Ocean Engineering | Year: 2016

2D modeling for surf zone phenomenons are validated in present work using the rotational Boussinesq-Green-Naghdi model. Three benchmark test cases are simulated: tsunami wave runup a conical island; tsunami wave runup complex shelf; and rip current and wave setup over sand bars. The computed results are compared to the experimental data including the free surface deformation and depth-averaged velocities. The simulated 2D cases fundamentally validate the model's ability in predicting wave transformation, wave breaking, wave runup and the velocity field for complex hydrodynamic conditions and give the basis for moving on to more complex applications. The lack of irrotationality would strongly contribute to the depth-varying velocity profile of rotational modeling, which has been partially proven in 1D undertow test (Zhang et al., 2014a). Unfortunately, few 2D experiments with rotational vortex data measured could be found due to the difficulty of recording the vortex characteristics. Future work would be the model application to much more complex geophysical and engineering problems, where the lack of any irrotational constrain is expected to excel. © 2015 Elsevier Ltd.


Wu L.-W.,Ocean University of China | Han X.-R.,Ocean University of China | Wu T.,National Marine Hazard Mitigation Service | Du J.,Ocean University of China | Shi X.-Y.,Ocean University of China
Zhongguo Huanjing Kexue/China Environmental Science | Year: 2016

In order to investigate the response of the macroalgae to heavy metal contamination, the influence of three heavy metal ions (Cu(II), Zn (II) and Pb(II)) on the uptake of nitrate by Ulva prolifera was investigated. Kinetic parameters related to nitrate uptake in different trials were determined by the batch culture experiment in the laboratory. The results showed that the uptake of nitrate by Ulva prolifera was promoted at low concentrations of Cu(II) (<0.04 mg/L) and Zn(II) (<0.12 mg/L) and inhibited at high concentrations (Cu(II)>0.10mg/L and Zn(II)>0.20 mg/L). Pb (II) played a negative role in the uptake of nitrate by Ulva prolifera at all tested concentrations. The inhibition rate of the maximum absorption rate of nitrate (Vmax) were calculated to be 0.23 mg/L, 0.66 mg/L, and 0.63 mg/L for Cu(II), Zn(II), and Pb(II), respectively. The inhibition effects of the three heavy metals at concentrations >0.5 mg/L on Ulva prolifera nitrate uptake were observed to be in the order of Cu(II)>Pb(II)>Zn(II). © 2016, Chinese Society for Environmental Sciences. All right reserved.


Ou W.,China Electric Power Research Institute | Zhao B.,China Electric Power Research Institute | Dai Y.,National Marine Hazard Mitigation Service
2016 6th International Workshop on Computer Science and Engineering, WCSE 2016 | Year: 2016

Based on RS, GIS technology and information quantity model, this paper will focus on the research of hazard evaluation method of landslides disaster in Fuling, Chongqing. Combining with theoretical basis of information quantity model, the evaluation method of this paper gives an improved model, and adds impacts of four dynamic factors: Rainfall, water level changes, vegetation and landuse. It was agreed that the hazard evaluation result of landslides can be divided into five grade level: very high, high, moderate, low and very low. According to the comprehensive evaluation, the result shows that the improved information quantity model and the additional dynamic effects are reasonable, and demonstrates that this method is objective and can provide effective guarantee for geological disaster prevention of the research area. The whole evaluation functions of the hazard evaluation system of landslides are finally realized on the ArcGIS platform with its modelling capabilities and custom development mode.


Shi X.,National Marine Hazard Mitigation Service | Liu Q.,National Marine Hazard Mitigation Service | Wang Y.,National Marine Hazard Mitigation Service
Journal of Natural Disasters | Year: 2015

Storm surge disaster gradation is the theoretical basis of storm surge disaster risk management and emergency planning. The grading result should not only reflect the severity of storm surge itself, but also include the social impact of storm surge disaster. The gradation of storm surge disaster includes hazard gradation and disaster situation gradation. There are no yet a national storm surge disaster classification standard. In this paper, different storm surge disaster gradation criteria from four perspectives, that is based on the intensity of storm surge hazard, taking storm surge defense capabilities into consideration, based on disaster loss, and based on disaster frequency, were systematically analyzed respectively. Based on all the gradation methods mentioned above, this paper takes Zhejiang Province as an example and compares the applicability and limitations of different gradation methods. At last, the factors that should be considered in storm surge disaster gradation were summarized and discussed, also the focus of storm surge disaster gradation in the future research was proposed.


Shi X.,National Marine Hazard Mitigation Service | Shi X.,Ocean University of China | Li H.,Ocean University of China | Han X.,Ocean University of China | And 2 more authors.
Huanjing Kexue Xuebao/Acta Scientiae Circumstantiae | Year: 2014

Field investigation was carried out from 24th August to 5th September, 2011 to study the effects of eddy, one of the most typical mesoscale oceanographical processes, on nutrients and dissolved oxygen in northern South China Sea. The results showed that the distribution of nutrients and DO was significantly influenced by eddy. As for horizontal distribution, nutrient concentrations decreased from inshore to offshore in the study area. Seawater of Dongsha archipelago presented high concentrations of N and Si and a low concentration of P, similar to that in Zhujiang River, indicating that anti-cyclonic eddies may push the Zhujiang river water to offshore. Results of vertical distribution pattern of nutrients and dissolved oxygen also indicated the importance of mesoscale oceanographical process in the study area. The nutrient concentrations at section B and C, located at the adjacent area of Zhujiang River, were relatively low. Surface water with low nutrient concentrations was observed to outspread to the bottom, and the nutrient isoline also moved downward, which may be influenced by the center of anti-cyclonic eddies. Bottom seawater with low temperature and high salinity was observed to move upward at section D and F, located around Hainan Island. These results imply that nutrients in surface water could be supplemented by bottom water with high nutrient concentrations, subsequently enhancing the growth of phytoplankton. Thus, section D and F may be influenced by the brink of anti-cyclonic eddies. Furthermore, low temperature, high salinity, high P and low DO were observed at section A close to Guangdong coastal areas and section E nearby the Dongsha archipelago, which may reflect the influence of upwelling in these areas.

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