Located in the circum-Pacific seismic zone, Taiwan is continually threatened by such natural disasters as typhoons, floods, landslides, and earthquakes, which increase risk of property loss and severely endanger public safety. Taipei City, the political and economic capital of Taiwan, must address disaster prevention and relief operations for compound disasters and extreme climatic events in addition to existing metropolitan disaster prevention operations. This study formulates 48 compound-disaster scenarios based on threats to Taipei City due to heavy rainfall and surrounding faults. Hydrology and flood analysis results and the Taiwan earthquake loss estimation system are utilized to assess the potential for compound disasters and the number of people they would displace in Taipei’s administrative districts. Analytical results can be used to create a pre-disaster static potential diagram and a refuge or shelter capacity assessment table. The disaster potential diagram is adopted to conduct geographic information system spatial and data analysis, and temporary refuges or shelters planned by the city government are integrated for shelter capacity comparison. Furthermore, a dynamic assessment curve for the number of displaced people during a disaster is plotted using data mining and attribute filtering. Subsequently, a cross table is obtained and employed to predict the number of refugees in the various administrative districts. Finally, conclusions and recommendations are provided for making disaster prevention and relief decisions simultaneously concerning earthquakes and flooding. 相似文献
The diffusion of hydrogen through platinum membranes has been measured at 450, 500, 550 and 600°C at 2000 bar pressure, using the hydrogen sensor technique. Ag + AgCl + 3 M HC1 was the starting solution inside the platinum tube. Hydrogen diffuses out of the platinum tube into a system containing Fe2O3 + Fe3O4 + H2O; that is, a solution with a fixed hydrogen fugacity. After quench, the drop in fH2 inside the platinum tube was calculated from measurements of pH and chloride molality. fH2 is initially roughly proportional to . Diffusion constants were calculated from these data by numerical integration, and the results can be expressed by logD (cm2/sec) = ? 5489.6/T, K - 4.648. 相似文献
The influence of pH on the rate of dissolution of various carbonates (calcite, aragonite, witherite, magnesite and dolomite) has been investigated at 25°C using a continuous fluidized bed reactor. The general rate dependence on pH observed for the simple carbonates is very similar and is in agreement with the results observed for calcite and aragonite by L.N. Plummer and coworkers. However, the rate of dissolution of magnesite is approximately four orders of magnitude lower than calcite.
For simple carbonates, the elementary steps involved in the dissolution reaction are:
where M represents the metal ion which can be Ca, Mg and Ba. According to the stoichiometry of the three reaction steps and the thermodynamic constraints, the total forward and backward rates can be expressed as:
Rf=k1aH+k2aH2CO3*+K3
rb=k-1aM2+aHCO3-+k-2aHCO3-+k-3aM2+aCO32-
The rate constants (k1, k2, k3 and k−3) determined with our experimental results for calcite, aragonite and witherite show that the dissolution rates are similar for these three minerals and that the nature of the cations does not play a significant role. The good agreement between the Ksp calculated from the measured k3/k−3 ratio and the theromodynamic value suggests that our dissolution mechanism is coherent.
The rate dependence on pH of the dissolution of dolomite obeys a fractional order at low pH's and confirms previously published observations therein. However, the two-step reaction mechanism proposed does not explain the fractional reaction order observed, which is likely due to a more complex surface reaction. 相似文献
The typical loess on high slopes along the BaoLan High-speed Rail, China, was selected as the research object. The influence of the freeze-thaw cycle and dry-wet alternation on the shear-strength parameters of the unsaturated loess was investigated by laboratory experimental methods. Moreover, the temperature field, seepage field, and stability of slopes with different gradients were simulated under the effect of the freeze-thaw cycle and dry-wet alternation by using the geotechnical analysis software Geo-Studio. The research results showed(1) when the freeze-thaw cycle was repeated on the slope, with the frozen depth increasing, the melted depth did the same; besides, the closed loop of isotherms formed on the slope;(2) under the action of dry-wet circulation, the negative pore-water pressure and volumetric water content showed an upward tendency. However, owing to the different slope gradients, rainfall infiltration was not the same. As time went by, the differences of the negative pore-water pressure and volumetric water content between the slopes of different gradients continued to increase;(3) with the freeze-thaw cycle and dry-wet alternation increasing, the slope-safety factor decreased. Especially in the early period, the slope-safety factor changed remarkably. For slopes undergoing freeze-thaw action, the slope-safety factor was negatively correlated with the gradient. However, with regard to slopes undergoing dry-wet alternation, the result became more complex because the slope-safety factor was related to both seepage strength and slope grade. Accordingly, further research is needed to study the effect of seepage strength and slope grade on the stability of loess slopes. 相似文献
This paper refers to the CNOP-related algorithms and formulates the practical method and forecast techniques of extracting predictable components in a numerical model for predictable components on extended-range scales.Model variables are divided into predictable components and unpredictable chaotic components from the angle of model prediction error growth.The predictable components are defined as those with a slow error growth at a given range.A targeted numerical model for predictable components is established based on the operational dynamical extended-range forecast(DERF)model of the National Climate Center.At the same time,useful information in historical data are combined to find the fields for predictable components in the numerical model that are similar to those for the predictable components in historical data,reducing the variable dimensions in a similar judgment process and further correcting prediction errors of predictable components.Historical data is used to obtain the expected value and variance of the chaotic components through the ensemble forecast method.The numerical experiment results show that this method can effectively improve the forecast skill of the atmospheric circulation field in the 10–30 days extended-range numerical model and has good prospects for operational applications. 相似文献
Purple clams (Hiatula rostrata Lighttoot) accumulate paralytic shellfish poisoning (PSP) toxins produced by a toxic strain of the dinoflagellate Alexandriun minutum Halim. The results confirm the data of our previous study concerning the muscle and siphon that were not showing a gradual rise in toxicity when shellfish accumulated more A. minutum. However, muscle and siphon are intermittently toxic both in exposure and depuration period in laboratory cultured purple clams. PSP toxins were detected in outdoor cultured purple clams, whereas no A. minutum were found in the culture pond during most of the survey time. The outdoor cultured purple clams need longer time to decrease toxicity to allowable levels than laboratory cultured purple clams. It was shown that laboratory data may not predict times over which pond-cultured purple clams may prove toxic to consumers. 相似文献