新型带弹簧支撑抗冲击研究及其在泥石流拦挡坝中的应用

为了使结构或构件能够更好地承受住泥石流、爆炸等冲击荷载,设计出一种新型带弹簧的支撑(件)。运用显式动力分析方法,对冲击载荷作用下的这种支撑进行数值模拟,计算得到新型支撑的动力响应,并与普通支撑进行对比分析。结果表明,新型支撑能更好地防止冲击荷载作用下的结构过早发生塑性变形。另外,在泥石流防治结构中,引入这种新型支撑,设计出新型泥石流拦挡坝。运用有限元软件ls-dyna对新型泥石流拦挡坝进行大块石冲击模拟,并与普通重力式拦挡坝进行对比分析,得出新型拦挡坝坝底应力远小于普通泥石流拦挡坝的应力。研究结果表明,新型带弹簧支撑及新型泥石流拦挡坝的抗冲击效果非常明显。     

Degradation Model: A Quantitative EIA Instrument,Acting as a Decision Support System (DSS) for Environmental Management

Environmental assessment of alternative development plans, programs, and policies may bring conflict among decision-makers, particularly when some quantitative measures for decision-making are needed and where cumulative impacts are neglected. Environmental impact assessment (EIA) and environmental economics theories, despite their usefulness, are not capable of addressing those issues and problems alone. In recent years, the decision support system (DSS) has provided some solutions, but mathematical analysis of the system to show the internal structure of the problem is not always possible. To addres the above shortcomings and ongoing problems of decision-making in Iran, a degradation model (DM) was introduced as an instrument of EIA, to act as a DSS for managers. The model is a compromise between knowledge-based decision support systems, detailed models, digested information models, and the basic theorem of environmental economics. In the present study (1996–2000), the model was applied in three provinces of Iran, representing three of four biogeographical regions of Iran. The study area was divided into a set of grids (100 km²). The degradation coefficient (H) was computed for all grids (1333), representing the degree of degradation in the grid. It is obvious that the higher the coefficient the more area is degraded and less prone to further development, and vice versa. In order to provide decision-makers with a set of quantitative measures to observe impacted areas (critical and noncritical) for resource allocation and further development, the degradation coefficients of all grids were classified into categories and criteria, using a fuzzy set theoretic approach. Accordingly, only 24% of study areas are prone to further development. The degradation model as a knowledge-based decision support system has its strengths and weaknesses, but it has solved managers' ongoing problems in Iran and it could be used elsewhere.     

事故定性分析与事故定量预测

分析了影响事故预测准确的原因,综述了国内外许多学者在事故预测方面所做的努力。指出今后事故预测工作的主要途径是由安全系统工程专家建立计算机支持的决策支持系统(DSS),由安全专家灵活运用这个系统中的计算机辅助研究方法(CAR)。     

Decision Tree Algorithm for Detection of Spatial Processes in Landscape Transformation

The conversion of landscapes by human activities results in widespread changes in landscape spatial structure. Regardless of the type of land conversion, there appears to be a limited number of common spatial configurations that result from such land transformation processes. Some of these configurations are considered optimal or more desirable than others. Based on pattern geometry, we define ten processes responsible for pattern change: aggregation, attrition, creation, deformation, dissection, enlargement, fragmentation, perforation, shift, and shrinkage. A novelty in this contribution is the inclusion of transformation processes causing expansion of the land cover of interest. Consequently, we propose a decision tree algorithm that enables detection of these processes, based on three parameters that have to be determined before and after the transformation of the landscape: area, perimeter length, and number of patches of the focal landscape class. As an example, the decision tree algorithm is applied to determine the transformation processes of three divergent land cover change scenarios: deciduous woodland degradation in Cadiz Township (Wisconsin, USA) 1831–1950, canopy gap formation in a terra firme rain forest at the Tiputini Biodiversity Station (Amazonian Ecuador) 1997–1998, and forest regrowth in Petersham Township (Massachusetts, USA) 1830–1985. The examples signal the importance of the temporal resolution of the data, since long-term pattern conversions can be subdivided in stadia in which particular pattern components are altered by specific transformation processes.     

Multi‐Criteria Decision Support Systems for Flood Hazard Mitigation and Emergency Response in Urban Watersheds1

Abstract: Flood management problems are inherently complex, time‐bound and multi‐faceted, involving many decision makers (with conflicting priorities and dynamic preferences), high decision stakes, limited technical information (both in terms of quality and quantity), and difficult tradeoffs. Multi‐Criteria Decision Support Systems (MCDSS) can help to manage this complexity and decision load by combining value judgments and technical information in a structured decision framework. A brief overview of MCDSS is presented, an original MCDSS architecture is put forth, and future research directions are discussed, including extensions to Multi‐Criteria Spatial Decision Support Systems and group MCDSS (as flood management involves shared resources and broad constituencies). With application to the September 11‐12, 2000 Tokai floods in Japan, the proposed multi‐criteria decision support instruments enhance communication among stakeholders and improve emergency management resource allocation. In summary, by making the links among flood knowledge, assumptions and choices more explicit, MCDSS increases stakeholder satisfaction, saves lives, and reduces flood management costs, thereby increasing decision‐making effectiveness, efficiency and transparency.     

Dynamic Modeling of Ground‐Water Quality Using Bayesian Techniques1

Abstract: Water industry experts have been arguing that the traditional techniques are not an accurate means of measuring water contamination. This is mainly because these techniques emphasize neither the stochastic nature of the water contamination process nor the precision and the accuracy of the tested methods used by environmental laboratories. In this work, we describe the development and application of prototype Dynamic Bayesian Networks (DBNs) that model ground‐water quality to determine the impact of chemical contaminants on ground‐water quality in the Salalah area, which is allocated to the south of Oman. We also present a new technique for data pre‐processing because it is needed for the treatment of ground‐water datasets that are used as the data source to learn the probabilities for dynamic decision models. Among more than 20 wells in area, only four wells were selected to be analyzed and the results show that we achieved an acceptable level of efficiency.     

Risk communication in emergency response to a simulated extreme flood

Risk communication in flood incident management can be improved through developing hydrometeorological and engineering models used as tools for communicating risk between scientists and emergency management professionals. A range of such models and tools was evaluated by participating flood emergency managers during a 4-day, real-time simulation of an extreme event in the Thamesmead area in the Thames estuary close to London, England. Emergency managers have different communication needs and value new tools differently, but the indications are that a range of new tools could be beneficial in flood incident management. Provided they are communicated large model uncertainties are not necessarily unwelcome among flood emergency managers. Even so they are cautious about sharing the ownership of weather and flood modelling uncertainties.     

洪水预报调度决策支持系统的设计与开发

基于C/S和B/S相结合的结构模式,开发了九龙江流域洪水预报调度决策支持系统。该系统采用了马斯京根矩阵解法、卡尔曼滤波实时校正、交互式调度方案生成、ASP等关键技术,实现了信息管理、洪水预报、洪水调度和系统管理等功能。     

基于运行机制的旅游扶贫支持系统和开发模式

旅游扶贫作为一种特殊性的开发扶贫形式,核心目标是以发展旅游业带动经济欠发达地区脱贫致富,但目前我国国内旅游扶贫工作仍然存在很多问题.在分析旅游扶贫特性和运行机制的基础上,提出了基于运行机制的旅游扶贫支持系统,阐述了该系统的构建基础及其要素组合,并分别从旅游资源相对优势、资源特性、区域经济、城乡关系及开发时序方面探讨了相应的开发模式,以此关注贫困人口和贫困社区利益这一核心问题.