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961.
B. van der Wateren‐De Hoog 《水文研究》1999,13(6):847-863
In this paper the validity of CADISSE, a regional storage capacity model developed to assess the sensitivity of catchment hydrology to climate variability, is examined. In CADISSE, catchment discharge sensitivity is expressed as the ratio of present maximum reservoir storage to catchment storage capacity. Present maximum storage should be interpreted as the maximum amount of water stored in a catchment at present. Catchment storage capacity is defined as the absolute amount of water that can be stored, given the catchment's dimensions and lithological characteristics. With CADISSE, catchment sensitivity can be quantified regionally using limited discharge data and topographic information. Furthermore, storage capacities can be assessed. CADISSE was successfully applied to 15 catchments in the Upper Loire Basin. However, successful application does not necessarily mean that the variables (present maximum storage and storage capacity) represent real world values. Therefore, a two‐step evaluation procedure is presented in this paper. To evaluate CADISSE, (1) the accurate assessment of regionally determined storage capacity, and (2) the importance of present maximum storage for catchment discharge sensitivity is examined with a daily discharge model by comparing observed and simulated catchment storage behaviour for dry and wet periods. The evaluation was carried out using the probability distributed daily discharge model, PDM, and a weather generator for three catchments with different storage capacities and storage behaviour. Results indicate that catchment storage capacity can be correctly quantified with CADISSE and that differences in storage behaviour are indeed important for analyses of catchment sensitivity. Hence, CADISSE has great potential as it can be used to identify flood‐ and drought‐prone catchments under present and future conditions. Copyright © 1999 John Wiley & Sons, Ltd. 相似文献
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岳西县自然斜坡在地球内、外动力共同作用下,容易变形并遭到破坏,造成人员伤亡和财产损失,严重制约了当地的经济发展。通过系统的工程地质调查和浅表生改造理论分析,查明了岳西县斜坡变形破坏特征及其成因,并探讨了其演化模式。结果表明,岳西县不同岩组的抗风化能力和力学特性存在差异,斜坡发生地质灾害的机理也不相同。根据斜坡结构特征,岳西县滑坡分为全风化层滑坡、强风化层滑坡和顺层岩质滑坡:全风化层滑坡的滑面位于全风化层中或全风化层与强风化层的分界线处;强风化层滑坡的滑面主要发育于强风化层与中风化层的分界线处;顺层岩质滑坡主要发育于片麻岩发育的顺向坡中。根据变形破坏方式,岳西县崩塌可分为滑移式崩塌、倾倒式崩塌和坠落式崩塌:滑移式崩塌主要由一组缓倾坡外结构面和另一组陡倾(坡外或者坡内)结构面控制;倾倒式崩塌主要由一组陡倾坡内结构面和另一组近水平发育的结构面控制;坠落式崩塌主要由一组结构面陡倾或近直立发育的结构面控制。岳西县滑坡多发育于风化壳厚度较大、岩体较松散、结构面强度低的地区;崩塌多发育于斜坡高陡、岩质风化程度低、结构面发育的地区。研究成果对岳西县乃至整个大别山地区地质灾害的研究及防治工作具有一定的借... 相似文献
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Alessandro?Caia Alberto?Giulio?Di?Lullo Giambattista?De?Ghetto Alberto?GuadagniniEmail authorView authors OrcID profile 《Stochastic Environmental Research and Risk Assessment (SERRA)》2018,32(9):2647-2666
The development of robust risk assessment procedures for offshore oil and gas operations is a major element for the assessment of the potential feedback between planned activities and the environment. We illustrate a methodological and computational framework conducive to (1) a quantitative risk analysis of deepwater well barrier failures and subsequent hydrocarbon release to the environment and (2) the analysis of the value of the deployment of conventional and/or innovative mitigation measures. Our methodological framework is grounded on historical records and combines the use of Dynamic Event Trees and Decision Trees from which we estimate probability of occurrence and impact of post-blowout events. Each sequence of response actions, which are undertaken immediately after the event or in the subsequent days, is considered within the context of appropriately structured event paths. This approach is conducive to an estimate of the expected value of key decisions and underlying technologies, with an emphasis on their potential to reduce the oil spill volume, which can critically impact the environment. Our study yields an original comparative analysis of diverse intervention strategies, and forms a basis to guiding future efforts towards the development and deployment of technologies and operating procedures yielding maximum benefit in terms of safety of operations and environmental protection. 相似文献
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Optimal design and seismic performance of tuned mass damper inerter (TMDI) for structures with nonlinear base isolation systems 下载免费PDF全文
The tuned mass damper inerter (TMDI) couples the classical tuned mass damper (TMD) with an inerter, a mechanical device whose generated force is proportional to the relative acceleration between its terminals, thus providing beneficial mass‐amplification effects. This paper deals with a dynamic layout in which the TMDI is installed below the isolation floor of base‐isolated structures in order to enhance the earthquake resilience and reduce the displacement demand. Unlike most of the literature studies that assumed a linearized behavior of the isolators, the aim of this paper is to investigate the effectiveness of the TMDI while accounting for the nonlinearity of the isolators. Two nonlinear constitutive behaviors are considered, a Coulomb friction model and a Bouc‐Wen hysteretic model, representative of friction pendulum and of lead‐rubber‐bearing isolators, respectively. Optimal design is based on the stochastic dynamic analysis of the system, by modeling the base acceleration as a Kanai‐Tajimi filtered stationary random process and resorting to the stochastic linearization technique to handle the nonlinear terms. Different tuning criteria based on displacement, acceleration, and energy‐based performance indices are defined, and their implications in a design process are discussed. It is proven that the improved robustness of the TMDI reduces its performance sensitivity to the tuning frequency and to the earthquake frequency content, which are well‐known shortcomings of TMD‐like systems. This important feature makes the TMDI particularly suitable for nonlinear base‐isolated structures that are affected by unavoidable uncertainties in the isolators' properties and that may experience changes of isolators effective stiffness depending on the excitation level. 相似文献
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