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81.
利用安徽省1961—2016年81个国家级地面气象观测站雨量、2006—2016年1 162个地面自动观测站小时雨量、1961—2016年安徽省民政厅灾情和2006—2016年《安徽省气象灾害年鉴》收录的227个暴雨过程灾情数据,采取气候平均、广义极值、概率密度函数、百分位分布等方法,统计暴雨过程的持续天数、区域、范围、平均日降水量和小时雨量对暴雨灾害的影响,划分安徽省暴雨灾害预警等级。结果表明:(1)安徽省暴雨灾害预警等级可分为Ⅳ级(轻度)、Ⅲ级(中度)、Ⅱ级(重度)、Ⅰ级(特重)四个等级;(2)从Ⅳ级到Ⅰ级,暴雨过程的持续天数指标从1—4 d,范围指标根据暴雨区占区域总面积的百分比确定,从Ⅳ级的20%上升至Ⅰ级的80%;(3)根据暴雨过程的区域差异,将安徽分为沿淮淮北、大别山区及皖南山区、沿江及江淮之间三个区域,分别建立降水量与暴雨灾情的定量关系,并在每个区域设置相应的平均日降水量和小时雨量指标;(4)利用上述暴雨灾害预警等级,对1981—2018年安徽省致灾的149个暴雨过程进行回代检验,并将其用于2020年6—7月安徽省暴雨灾害预警,暴雨灾害预警发布周期为Ⅳ级(轻度)0.66~0.82 a、Ⅲ级(中度)1.15~1.90 a、Ⅱ级(重度)3.16~3.80 a、Ⅰ级(特重)9.5~12.6 a,符合安徽暴雨灾情实际,可以为气象部门启动暴雨应急响应提供参考。
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基于信息量模型的玉树地震次生地质灾害危险性评价 总被引:1,自引:0,他引:1
2010-04-14发生在青海省玉树的Ms7.1级地震引发了大量的地质灾害.基于GIS技术和信息量模型方法,以坡度、坡向、高程、坡形、地貌类型、断层距和地层岩性为评价因子,通过空间分析计算各因子的信息量,分析地质灾害在各因子中的空间分布特征,对各评价因子图层进行空间建模,将获取的信息量图划分为高度、中度、轻度三级危险区,通过遥感解译研究区实际滑坡分布,与危险性分布图叠加表明:本次研究得出的危险等级与实际的滑坡发生情况相吻合,为灾区重建提供参考依据. 相似文献
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In a Cost-Benefit Analysis (CBA) or an Environmental Impact Assessment (EIA), determining the value that the general public attaches to a landscape is often problematic. To aid the inclusion of this social value in such analyses, a Google Maps-based tool, called the HotSpotMonitor (HSM), was developed. The HSM determines which natural places are highly attractive by having people mark such places on a map. The definition of attractiveness remains open to avoid having marker placement being influenced by preconceived thoughts. The number of markers an area receives is considered to indicate its social value. Six regions were selected, and from these, stratified samples were drawn (total n = 3293). Participants placed markers at three spatial levels: local, regional and national. This paper focuses on the markers at the national level. The first research question is whether the HSM can produce an accurate map of highly attractive places at a national level. The results indicated that while in principle HSM can produce such a map, the spatial representativeness of the sample is important. The region of origin of the participants influenced where they placed their markers, an effect previously termed spatial discounting. The second research question considers which qualities the participants associate with the marked places. These qualities were very similar at all three spatial levels: green, natural, presence of water and quiet were often selected out of the fourteen suggested qualities. The third, and more exploratory, research question concerns which characteristics of an area predict its attractiveness. Natural and forest areas had higher marker densities than water surfaces or all other types of land use combined. The discussion evaluates the potential of the HSM to generate input on social landscape values for CBAs and EIAs. 相似文献
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介绍了次声波的基本物理概念和次声波的传播特性,概述了次声波的研究现状,提出了利用次声波来预警海啸灾害的建议,并对其可行性进行了分析。 相似文献
88.
Numerical studies of methane production from Class 1 gas hydrate accumulations enhanced with carbon dioxide injection 总被引:2,自引:0,他引:2
Class 1 gas hydrate accumulations are characterized by a permeable hydrate-bearing interval overlying a permeable interval with mobile gas, sandwiched between two impermeable intervals. Depressurization-induced dissociation is currently the favored technology for producing gas from Class 1 gas hydrate accumulations. The depressurization production technology requires heat transfer from the surrounding environment to sustain dissociation as the temperature drops toward the hydrate equilibrium point and leaves the reservoir void of gas hydrate. Production of gas hydrate accumulations by exchanging carbon dioxide with methane in the clathrate structure has been demonstrated in laboratory experiments and proposed as a field-scale technology. The carbon dioxide exchange technology has the potential for yielding higher production rates and mechanically stabilizing the reservoir by maintaining hydrate saturations. We used numerical simulation to investigate the advantages and disadvantages of using carbon dioxide injection to enhance the production of methane from Class 1 gas hydrate accumulations. Numerical simulations in this study were primarily concerned with the mechanisms and approaches of carbon dioxide injection to investigate whether methane production could be enhanced through this approach. To avoid excessive simulation execution times, a five-spot well pattern with a 500-m well spacing was approximated using a two-dimensional domain having well boundaries on the vertical sides and impermeable boundaries on the horizontal sides. Impermeable over- and under burden were included to account for heat transfer into the production interval. Simulation results indicate that low injection pressures can be used to reduce secondary hydrate formation and that direct contact of injected carbon dioxide with the methane hydrate present in the formation is limited due to bypass through the higher permeability gas zone. 相似文献
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