NATIONAL FLOOD INSURANCE AND THE COASTAL ZONE: A CASE STUDY OF HURRICANE ELOISE1

ABSTRACT: This paper presents evidence that currently published flood insurance premiums may be insufficient to cover expected losses in coastal areas subject to hurricane. The problems of developing flood premiums in coastal zones are discussed and Federal Insurance Administration (FIA) reaction to these problems analyzed. Flood losses in the coastal zone of Bay County, Florida due to hurricane Eloise are compared with losses which would be predicted by the FIA. This comparison raises important questions concerning the adequacy of flood premiums in coastal zones and the undesirable indirect effects that underpricing flood risk will have on location decisions in the coastal floodplain.     

IMPACT ASSESSMENT MODEL FOR CLEAR WATER FISHES EXPOSED TO EXCESSIVELY CLOUDY WATER1

ABSTRACT: A new type of empirical model described here enables real time assessment of impacts caused by excessive water cloudiness as a function of (a) reduced visual clarity (excessive cloudiness) and (b) duration of exposure to cloudy conditions, in fisheries or fish life stages adapted to life in clear water ecosystems. This model takes the familiar form used in earlier suspended sediment dose effect models where z is severity of ill effect (SEV), x is duration of exposure (h), y is black disk sighting range (y BD, m)—a measure of water clarity, a is the intercept, and b and c are slope coefficients. As calibrated in this study the model is Severity of ill effect is ranked on a 15‐step scale that ranges from 0 to 14, where zero represents nil effect and 14 represents 100 percent mortality. This model, based on peer consultation and limited meta analysis of peer reviewed reports, accomplishes the following: (a) identifies the threshold of the onset of ill effects among clear water fishes; (b) postulates the rate at which serious ill effects are likely to escalate as a function of reduced visual clarity and persistence; (c) provides a context (the “visual clarity” matrix, with its cell coordinates) to share and compare information about impacts as a function of visual clarity “climate” (d) demonstrates changes in predator prey interactions at exposures greater than and less than the threshold of direct ill effects; (e) calibrates trout reactive distance (cm) as function of water clarity in the form where y represents reactive distance (cm) and x represents visual clarity (black disk sighting range, cm), and where a and b are intercept and slope respectively, such that (f) identifies black disk sighting range, in meters, and its reciprocal, beam attenuation, as preferred monitoring variables; and (g) provides two additional optical quality variables (Secchi disk extinction distance and turbidity) which, suitably calibrated as they have been in this study, expand the range of monitoring options in situations in which the preferred technology—beam attenuation equipment or black disk sighting equipment—is unavailable or impractical to use. This new model demonstrates the efficacy of peer collaboration and defines new research horizons for its refinement.     

电离辐射防护涂料的研究

针对电离辐射的危害及防护,重点介绍了具有吸收、屏蔽射线功能的防辐射涂料的构成及要求。报导了一种对χ—射线(γ—射线)具有良好的屏蔽、吸收功能的涂料的研制过程和测试结果。该涂料由一种单相、均匀、化学性质稳定、分散性能优良、有较优的屏蔽能力的无机固熔体填料,配以经改性的耐高温骨架材料而构成。该涂料施工方便、涂膜光亮、无公害,可望在广泛的领域内有大的应用前景。     

华南寒潮气候特征研究

本文利用华南地区４８站逐日气温资料，分析寒潮气候特征．经分析发现：华南寒潮频数由北向南减少，内陆多于沿海。寒潮过程年代际变化有逐渐减少的趋势。华南寒潮平均过程降温居全国之首，８０％以上集中在１０．０～１９．０℃降温幅度内。     

Impact of a shock wave on a structure on explosion at altitude

The number of explosive attacks on civilian buildings has recently increased and the pattern of damage inflicted on structures when an explosion takes place at altitude remains quite difficult to predict. The primary aim of the work reported here was to enhance the understanding of how blast waves from an explosion at altitude interact with the ground and with a structure. Small-scale experiments were conducted using a propane–oxygen stoichiometric mixture as explosive. This approach is original because it models high-explosive detonation in terms of gaseous charge explosion using TNT equivalents. Several non-dimensional laws are expressed and validated by experiments. These relationships allow determination of the propagation of a blast wave and its interaction with a structure as a function of the position of the explosive charge when the explosion occurs at altitude. Then, from knowledge of the blast loading, using Hopkinson's scaling law and TNT equivalents, we can predict the interaction of blast waves with the ground and a structure on a real scale. Simulations were performed using the Autodyn code, and good correlation with the experimental results was obtained.     

爆炸冲击波在建筑群中传播规律的数值模拟研究

为了研究建筑群的布局特性对爆炸冲击波传播的干扰作用及爆炸对周围环境的影响,笔者基于任意拉格朗日多物质流固耦合算法,对空气采用ALE网格,爆轰产物采用JWL状态方程,利用LS-DYNA程序对TNT理想爆炸源的爆炸进行了数值模拟,并与经验公式的计算结果进行了对比,得出了数值模拟方法可行的结论。在该基础上,以一个建筑小区为例,对其遭受爆炸后的响应作了进一步模拟研究。结果表明,建筑物的密度和布局方式对爆炸场的数值与形态都有敏感作用,因此,在城市规划建筑布局阶段,应考虑建筑密度和布局对爆炸冲击波的影响。     

隧道含水断层破碎带的探测

以泉三高速公路某隧道含水断层为例,对比瑞利波和地质雷达两种探测技术,论述其优缺点,阐明瑞利波探测技术探测公路施工隧道含水断层破碎带的优点。     

Computer-aided modeling of the protective effect of explosion relief vents in tunnel structures

This paper aims at contributing to the efficient design of explosion protection systems against confined explosions. The issue addressed concerns the quantitative estimation of the protective effect of explosion relief vents in the case of confined explosions inside tunnels. A series of virtual experiments performed by computer simulation, revealed how the number of vents, their diameter, as well as the angle between the vents and the tunnel, influences the blast wave attenuation. The computational study was performed considering a complicated large-scale tunnel configuration with branches on its half portion. The purpose was the calculation of the attenuation effect due to the presence of vents by comparing the total explosion-specific impulse developing at antidiametric positions inside the tunnel. Simulations were carried out via a three-dimensional numerical model built in the computational fluid dynamics code CFX 5.7.1, which has been validated in previous papers against experimental overpressure histories data demonstrating reasonable performance. Computer results showed that the use of branch vents provides an effective method for shock wave attenuation following an explosion, whereas their statistical elaboration revealed that the attenuation is mainly affected by the number of vents and their diameter. In contrast, the angle between the side vents and the main tunnel appeared to slightly affect the pressure wave weakening. Eventually, the quantitative influence of the above parameters was effectively illustrated in functional diagrams, so that the total attenuation effect may be promptly estimated, if the design variables are known. In addition, two statistical models with reasonable fitting to the calculated data are proposed, which express the attenuation effect as a dependent variable of the design variables including their interactions.     

数字化记录地震分析中的一个技巧

本文通过远震S波到时减P波到时(或极远震PP到时减PKP到时)之差与地震最大面波到时的关系,来推测一个地震发生后,只要震相S、P(或PP、PKP)已确定,就能推测最大面波的到时。反过来,最大面波到时一定,就能基本确定S(或PP)波到时的大致位置,再根据其它震相在S(或PP)波前后出现的规律,从而可靠的分析地震,在地震速报和震相分析当中很有实用价值。     

河水-地下水交互带内砷及金属的自然衰减过程

在简单介绍污染物自然衰减作用定义的基础上,重点分析了河水-地下水交互带内As和以矿山废水为来源的金属污染物的自然衰减行为:主要包括吸附作用,氧化还原作用,生物转化作用等。其中详细介绍了金属Fe、Al的氢氧化物/氧化物对As化合物和其他金属如Cd、Cu和Zn等的吸附作用;Ca2+、Fe2+、磷酸盐、重碳酸盐等阴阳离子和天然有机质对吸附作用的影响;金属微生物氧化还原作用以及微生物作用下As(V)与As(III)的相互转化过程。研究发现,阳离子可以增强金属的吸附作用,阴离子主要是参与竞争吸附;天然有机质对金属吸附过程的抑制作用阻碍金属的固定;交互带内氧化还原条件的变化可以引起一系列的氧化还原反应;微生物催化还原不利于As的自然衰减。最后指出目前河水-地下水交互带内金属污染物衰减过程研究存在的问题以及今后的发展方向。