REGIONAL SCALE MODELING OF SURFACE AND GROUND WATER INTERACTION IN THE SNAKE RIVER BASIN1

ABSTRACT: Changes in irrigation and land use may impact discharge of the Snake River Plain aquifer, which is a major contributor to flow of the Snake River in southern Idaho. The Snake River Basin planning and management model (SRBM) has been expanded to include the spatial distribution and temporal attenuation that occurs as aquifer stresses propagate through the aquifer to the river. The SRBM is a network flow model in which aquifer characteristics have been introduced through a matrix of response functions. The response functions were determined by independently simulating the effect of a unit stress in each cell of a finite difference groundwater flow model on six reaches of the Snake River. Cells were aggregated into 20 aquifer zones and average response functions for each river reach were included in the SRBM. This approach links many of the capabilities of surface and ground water flow models. Evaluation of an artificial recharge scenario approximately reproduced estimates made by direct simulation in a ground water flow model. The example demonstrated that the method can produce reasonable results but interpretation of the results can be biased if the simulation period is not of adequate duration.     

非活动隐伏断层对结构地震反应的影响

采用有限元方法分别建立了包含隐伏断层和不包含断层的场地模型，分析了在各种频率水平入射波作用下该场地地面结构的动力反应。计算结果表明，隐伏断层对地面结构的动力反应有一定的放大作用，特别是当入射波的频率与场地的基频接近时，放大效应更为明显。这一结果说明，在包含隐伏断层的场地进行重大工程建设时，需要考虑断层对地震动的影响。     

大坝减震气幕实验研究

针对平面模型 ,从流固耦合理论出发 ,以有限元分析为主要研究手段 ,应用基于理想气体状态方程的气幕隔震的压力有限元模型 ,计算坝体动力响应。结果表明气幕对大坝有良好的隔震性能 ,可降低水压力75 %以上。针对平面模型 ,用初位移激震分几种工况进行实验。用位移传感器测得坝面的位移时程 ,动水压力用脉动传感器进行测量。模型实验得到气幕减震后 ,动水压力降低 70 % ,与计算结果基本相符。证明了理论的正确性。     

中国自然灾害应急管理研究进展与对策

从中国自然灾害应急管理的现状出发,系统分析了自然灾害应急管理领域的研究进展,指出了中国自然灾害应急管理在理论和实践方面存在的问题.在此基础上,提出了中国自然灾害应急管理框架,认为建立适合中国国情的自然灾害应急管理体制是提高中国自然灾害应急管理的基础;应急预案的制定和实施是规范灾害应急管理,提高灾害紧急救援能力的关键措施;灾害信息快速准确的获取和评估是灾害应急管理的有效保障;建立实际可用的应急管理系统是提高灾害应急管理水平和工作效率的根本出路.     

强震数据线性模型曲线的反应谱计算及其误差问题

文献研究给出了用线性模型曲线理论来计算地震加速度数据的反应谱理论.文献又给出了它的简便算法,但这算法忽视了强震丢头记录中初始点数据一般为非零值的影响.本文为此研究给出了更为普通和实用的包括初始数据点为任意值时的间便算法. 给出算例.将这线性模型理论的反应谱计算结果与作者新近研究的时限光滑化模型曲线精确理论计算结果作了对照,反映出用线性模型理论计算存在误差的状况.     

DESIGNING FOR DYNAMIC EQUILIBRIUM IN STREAMS1

ABSTRACT: Streams are dynamic systems, so steady state does not exist for any appreciable period of time. Streams in dynamic equilibrium respond quickly to change, regaining a new equilibrium. From the response system it follows that there is a causative reason why a stream meanders or degrades or aggrades its bed. These actions represent adjustment processes. If humans interfere with them, other adjustment processes will be initiated. In contrast, if humans work with the ongoing processes, success will be attainable with less efforts and at a lower cost. Local base level change represents one of the most influential channel changes, especially the lowering of this level. Loss of base level may cause degradation throughout a stream network, because the main stem is the base level for all its tributaries. Often, degradation causes bank instability and lowering of streamside water tables that, in turn, endanger the riparian ecosystem. Judging from check dam systems, a rise of the local base level does not raise the bed throughout a stream or network; instead, aggradation stops at a given distance. Preventing local base level changes of a stream network, therefore, is a cost-effective measure. Examples are presented of treatments causing new critical situations and measures to correct them.     

STREAM IMPROVEMENTS AND FISH RESPONSE: A BIO-ENGINEERING ASSESSMENT1

ABSTRACT: Human modifications of natural streams in the name of habitat improvement take various forms, and the impacts of those improvements, both positive and negative, vary by orders of magnitude from stream to stream. The positive impacts are achieved through careful and timely planning, design, installation and monitoring of projects. Negative impacts are the results of rush jobs dictated by available money, a lack of consideration for limiting factors, untrained and inexperienced personnel, force-fitting structures instead of bending the flow, lack of a watershed plan, poor communication and cooperation among disciplines, not using the team approach, and single habitat solutions which neglect diversity and artificial constraints. These problems are discussed from various perspectives, but emphasis on an integrated, bioengineering approach is threaded throughout the discussion of the problems and benefits associated with stream improvements and fish response. A general systems approach is presented which uses common language as a focal point for interdisciplinary communication, which is one of the major problems in resource management. Various conceptual models are discussed to describe system complexities, and factors which constrain project evaluation in terms of biological, physical, economic and other components. Conclusions about why some projects are successful, while others are not, are followed by recommendations for concerted and diversified efforts to improve our success in stream stewardship.     

Problems in local emergency management

Local governments (county and city) take the most active role in responding to natural and manmade disasters, yet very little is understood about the role of the emergency manager-the administrator who organizes and coordinates the emergency response of a community. This article describes the more common organizational niches that emergency managers are placed into, and it examines some of the political, institutional, and budgetary constraints that hinder the emergency manager's operations. Finally, it suggests strategies for solving these problems and identifies areas for further research.     

我国危化品应急响应系统存在问题及改进

危化品应急响应系统已经成为危化行业安全生产的重要环节。对国内外危化品应急响应系统进行了对比，得到我国的危化品应急响应系统存在比较显著的特点，并对于如何借鉴国外已有经验发展我国的危化品应急响应系统提出了建议。     

SMA绞线-叠层橡胶复合支座结构的动力反应

为了改进现有普通叠层橡胶支座的隔震效果，利用形状记忆合金的超弹性，将SMA绞线加入叠层橡胶支座中，形成了SMA绞线-叠层橡胶复合支座。分析了SMA绞线-叠层橡胶复合支座的工作原理，建立了其力学分析模型，并进行了应用SMA绞线-叠层橡胶复合支座的结构动力反应分析，导出了加速度衰减比尺。与位移放大比凡的理论形式，并利用具体算例，研究了频率比和阻尼比对结构隔震效果的影响。结果表明，频率比越大，阻尼比越小，隔震效果越好。