泥石流灾害风险评价方法及其应用研究

探讨泥石流灾害风险评价的理论和方法;利用已有的泥石流灾害资料,建立泥石流风险评价体系和实施流程;提出风险评价的定量计算方法;结合遥感和地理信息系统技术,完成了云南省昆明市东川区泥石流灾害的定量风险评价。研究结果与泥石流实际分布和调查资料基本一致,表明所提出的泥石流灾害风险评价的理论与方法具有一定的理论价值和现实意义,可以为泥石流灾害风险评价和防灾减灾管理提供有益的科学依据。     

Anthropogenic metal cycles in China

The flows and stocks of seven important industrial metals were characterized for mainland China for several years in the dynamically changing decade of 1994–2004. One-year snapshot cycles are provided for chromium, nickel, and silver. For copper, zinc, lead, and iron, multiple-year cycles have been completed; they demonstrate that the flows of these metals into use in China doubled between 2000 and 2004. Although the Chinese per capita flows from production to disposal are mostly shown to be below the global average rate, they are increasing or are expected to increase dramatically. The metal resource efficiency is evaluated for several indicators of material flow analysis; these metrics for China are also below the global average values. The research quantitatively illustrates that China’s metal cycles may pose significant resource and environmental challenges in terms of their magnitudes and potential for growth.     

A method for regional-scale material flow and decoupling analysis: A demonstration case study of Aichi prefecture, Japan

We have developed a method to analyse the annual material flow in a prefecture and have calculated environmental indicators for a prefecture. Material flow analysis (MFA) is important to clarify the structure of a regional society and obtain environmental indicators for a circular society. However, MFA has not advanced in local governments because of few local statistics. We have developed a method to analyse the annual material flow in Aichi prefecture from 1980 to 2000 using an input–output (I–O) table and statistics of Aichi. We have verified the accuracy of this method by comparing its results for 2000 which calculated on the basis of official I–O table for 1995 with the I–O table data for 2000; the correlation coefficient obtained in this case is greater than 0.95. Moreover, by performing MFA, we have estimated the resource consumption and decoupling indicator of each industry in Aichi prefecture from 1980 to 2000. We could obtain more detailed and accurate environmental indicators by using our method. From these results, we could estimate the progress of Aichi prefecture towards a circular society.     

Channel flow and trichloroethylene treatment in a partly iron-filled fracture: experimental and model results

Technical developments have now made it possible to emplace granular zero-valent iron (Fe(0)) in fractured media to create a Fe(0) fracture reactive barrier (Fe(0) FRB) for the treatment of contaminated groundwater. To evaluate this concept, we conducted a laboratory experiment in which trichloroethylene (TCE) contaminated water was flushed through a single uniform fracture created between two sandstone blocks. This fracture was partly filled with what was intended to be a uniform thickness of iron. Partial treatment of TCE by iron demonstrated that the concept of a Fe(0) FRB is practical, but was less than anticipated for an iron layer of uniform thickness. When the experiment was disassembled, evidence of discrete channelised flow was noted and attributed to imperfect placement of the iron. To evaluate the effect of the channel flow, an explicit Channel Model was developed that simplifies this complex flow regime into a conceptualised set of uniform and parallel channels. The mathematical representation of this conceptualisation directly accounts for (i) flow channels and immobile fluid arising from the non-uniform iron placement, (ii) mass transfer from the open fracture to iron and immobile fluid regions, and (iii) degradation in the iron regions. A favourable comparison between laboratory data and the results from the developed mathematical model suggests that the model is capable of representing TCE degradation in fractures with non-uniform iron placement. In order to apply this Channel Model concept to a Fe(0) FRB system, a simplified, or implicit, Lumped Channel Model was developed where the physical and chemical processes in the iron layer and immobile fluid regions are captured by a first-order lumped rate parameter. The performance of this Lumped Channel Model was compared to laboratory data, and benchmarked against the Channel Model. The advantages of the Lumped Channel Model are that the degradation of TCE in the system is represented by a first-order parameter that can be used directly in readily available numerical simulators.     

侧部点式排烟隧道火灾临界风速研究

为得到侧部点式排烟模式隧道火灾临界风速无量纲计算式,针对隧道侧部点式排烟模式,根据π定理和相似理论,采用量纲分析方法分析影响临界风速的相关因素,推导出影响临界风速3个因素的无量纲函数关系式;采用数值模拟方法,确定临界风速与火灾热释放速率、排烟量、排烟口距火源距离的量化关系.研究结果表明:当无量纲排烟口距火源距离小于2....     

基于雨量(强)条件的泥石流预测预报研究现状、问题与建议

在对基于雨量(强)条件泥石流预测预报现状综合分析的基础上,提出了目前降雨型泥石流预测预报中存在的问题:①前期降雨对泥石流发生的贡献问题;②前期降雨对泥石流影响的衰减问题;③前期有效降雨天数的确定问题;④前期降雨和短历时降雨的权重衡量问题;⑤基于前期有效雨量的泥石流预测预报模式的确定问题。提出了降雨型泥石流预测预报程式框架和相关建议:①基于雨量(强)条件的泥石流预测预报应同机理研究密切结合;②单沟泥石流临界雨量条件和预测预报应同泥石流类型密切结合;③区域泥石流临界雨量条件和预测预报应同环境地质背景密切结合。     

地铁隧道不同排烟风速对火灾烟气控制的模拟分析

以某地铁隧道过江段为研究对象,基于CFD数值模拟方法,采用大涡模拟火灾分析软件FDS对相同纵向风速条件下,排烟道内不同排烟风速对地铁列车火灾烟气控制效果的影响进行模拟对比分析,分析结果可为设计单位对在排烟风机的选取提供一定的参考。模拟分析的结果表明,当纵向风速设定为1m/s时,排烟风道内排烟风速为5m/s即能达到较好的地铁列车火灾烟气控制效果。     

基于Copula模型的降雨量与土壤饱和度的模拟研究

采用两步法,针对云南东川蒋家沟流域的降雨量与土壤饱和度,建立了边缘为皮尔逊Ⅲ型的Clayton Copula模型,分析了降雨量和土壤饱和度之间相关结构,以及两变量重现期,模拟了流域内土壤饱和度的变化情况。实例表明所构造的Clayton Copula模型能比较好地模拟出流域内土壤饱和度在降雨情况下逐日变化情况,有助于进一步认识降水对土壤饱和度的作用过程,并为分析泥石流灾害的发生提供了一种新思路。     

云南省东川区泥石流灾害SPOT5遥感影像特征

在东川区县(市)地质灾害详细调查过程中,SPOT5高分辨率卫星遥感数据对泥石流灾害具有较好的解译效果。通过对泥石流SPOT5遥感影像特征进行研究,建立了东川区泥石流遥感解译标志,并对沟谷型泥石流和坡面型泥石流进行识别,共识别了沟谷型泥石流168条,坡面泥石流95处。     

城市高架道路系统抗震性能分析

城市高架道路系统是城市交通系统的抗震薄弱环节,其震害不仅影响其自身的通行能力,通常还会影响高架道路下方的地面交通.对高架道路系统抗震性能的分析方法进行了系统阐述.采用系统分析方法对上海市内环高架道路系统进行了抗震性能分析,得到了震后系统通行时间延长值,而震后系统通行时间延长反映了系统通行能力的降低.