Study of the comprehensive risk analysis of dam-break flooding based on the numerical simulation of flood routing. Part I: model development     

Ruirui Sun  Xiaoling Wang  Zhengyin Zhou  Xuefei Ao  Xiaopei Sun  Mingrui Song 《Natural Hazards》2014,73(3):1547-1568

Dam-break floods have been of increasing concern to safety engineers and decision makers. The presence of complex terrain in inundation areas multiplies the simulation difficulty of flood routing. In previous studies, representing the flood routing parameters empirically does not reflect the characteristics of flood routing, which strongly influences the accurate assessment of the dam-break consequences. The basis for carrying out dangerous reservoir reinforcement is just engineering safety, without considering the actual situation of downstream areas. In this study, a comprehensive risk analysis of the dam-break flood was implemented based on the numerical simulation of flood routing. First, coupled with the volume of fluid method, a three-dimensional k–? turbulence mathematical model was developed for flood routing in complex inundation areas. Then, based on the flow parameters obtained through computational fluid dynamics modeling, the attribute measure methodology was used for the evaluation of consequences combined with the calculation of the dam-break consequences (loss of life, economic loss, social and environmental influence). Furthermore, a methodology containing the combined weight method and the technique for order performance by similarity to ideal solution method was proposed for risk ranking of dangerous reservoirs due to its logical consideration of scalar values that simultaneously account for both the best and worst alternatives. Finally, a sensitivity analysis was performed to provide information about the stability of risk ranking. The aforementioned model and methodology are applied to a case involving five reservoirs in the Haihe River Basin in China for Part II of this study.  相似文献   

Study of the comprehensive risk analysis of dam-break flooding based on the numerical simulation of flood routing. Part II: Model application and results     

Zhengyin Zhou  Xiaoling Wang  Ruirui Sun  Xuefei Ao  Xiaopei Sun  Mingrui Song 《Natural Hazards》2014,72(2):675-700

The present model and methodology described in Part I of this work are applied to perform a comprehensive risk analysis of the dam-break flood of five reservoirs in the Haihe River Basin, China. The results indicate that the three-dimensional numerical simulation considering complex terrain can reflect the characteristics of flood routing and the three-dimensional phenomena. Based on the simulation results, it can be concluded that the risk grades of the consequences induced by a gradual or instantaneous dam break of the Dongwushi reservoir are extremely serious, as determined through the attribute synthetic approach. The results obtained from ranking the risk by the technique for order performance by similarity to ideal solution method are that the Dongwushi reservoir has the most serious consequences when the dam breaks followed by the Lincheng reservoir, the Miaogong reservoir and the Yunzhou reservoir, and the Youyi reservoir has the least severe consequences. Though the ranking of the relatively comprehensive risk coincides with that of the consequences, the dam safety measured by the dam failure probability plays an important role in ranking the risk. A sensitivity analysis is performed by individually increasing the weight of each criterion by 20 %, and the ranking order is not changed, suggesting that the evaluation model is reasonable, stable and reliable.  相似文献   

基于地理尺度的中国人居环境研究进展   总被引：1，自引：0，他引：1  

李雪铭  徐梁  田深圳  杨俊  刘美含  刘贺 《地理科学》2022,42(6):951-962

对国内人居环境的地理尺度进行了新的划分,主体分为现实人居环境、意象人居环境和拟态人居环境（即“三态”）,采用“主观文献归纳+客观文献计量”的方法对地理尺度视角下的人居环境内容、数据和方法等进行评述与展望。① 研究内容趋向综合集成化、新人地关系“广深化”和尺度交叉化等;② 研究数据表现出质度和量度的优化态势、多源数据的时空融合趋势和“小数据+大数据”的组合互补方向等;③ 研究方法体现在质性研究的更新化、计量模型的丰富化和“大数据智能分析+小数据抽样调查”的聚合化等。未来,国内人居环境研究应深化“一横+一纵”的逻辑分析原则,横向尺度关注居住、工作、交通、游憩等不同人类活动的时空特征,纵向尺度关注现实人居环境、意象人居环境及拟态人居环境融合趋势下人类聚居的深层结构,围绕着“三态”人居行为逐步完善为多视角、多领域和系统综合的学科群组。  相似文献   

保护性耕作改善东北农田黑土土壤生物多样性及其生态功能   总被引：2，自引：0，他引：2  

张士秀  贾淑霞  常亮  陈学文  张延  杨学明  梁爱珍 《地理科学》2022,42(8):1360-1369

保护性耕作是攻克黑土地保护和利用的核心技术之一。研究立足中国科学院黑土区农业生态重点试验室保护性耕作长期定位试验基地,系统梳理总结了农田黑土土壤生物多样性对保护性耕作的响应特征。与传统耕作相比,保护性耕作显著增加各生物类群（微生物、线虫、跳虫、螨类及蚯蚓）的物种丰富度（1%~8%）、数量（25%~57%）和生物量（30%~50%）,提高食物网网状结构的复杂性及各营养级间的连通性（14%~32%）,促进土壤生物在固土蓄水、土壤碳固存、氮素高效利用以及稳定作物产量四方面生态功能的可持续性发挥。研究结果表明,实施保护性耕作可有效利用土壤生物的功能潜力,实现东北黑土区农田生态系统的健康发展、服务国家粮食安全产业带建设和现代农业发展。  相似文献   

Bootstrap aggregating approach to short-term load forecasting using meteorological parameters for demand side management in the North-Eastern Region of India     

Sarkar  Dipu  Ao  Taliakum  Gunturi  Sravan Kumar 《Theoretical and Applied Climatology》2022,148(3-4):1111-1125

Theoretical and Applied Climatology - Electricity is an essential commodity that must be generated in response to demand. Hydroelectric power plants, fossil fuels, nuclear energy, and wind energy...  相似文献   

构造附加动力对煤变质过程的影响          下载免费PDF全文

敖卫华  黄文辉  唐修义  陈萍 《地质科学》2012,47(2):517-529

本文从固体力学、构造物理化学的角度分析了煤岩所受应力的来源、性质以及应力在煤变质过程中的影响方式。作者在前人研究基础上,阐述了构造动力影响过程中煤岩能量的转换形式,分析了应力在烟煤分子团聚过程中的影响。研究认为,煤岩所受的各种应力(压应力、拉应力、剪应力)为地层压力与构造动力所造成的附加内力。这种附加内力可以分解为构造附加静水压力与偏应力两部分。构造附加静水压力主要影响煤岩的物理性质,如孔隙度、颗粒性质与瓦斯吸附特征,并对煤的化学煤化过程有缓慢促进作用。偏应力主要使煤岩发生变形和位移。煤化过程中,由构造运动所产生的动能转化为各种形式的热能、表面能、弹性变形能以及声、光、电、磁等形态能量。  相似文献   

Recent improvements to the physical model of the Bohai Sea,the Yellow Sea and the East China Sea Operational Oceano-graphy Forecasting System     

Ang Li  Xueming Zhu  Yunfei Zhang  Shihe Ren  Miaoyin Zhang  Ziqing Zu  Hui Wang 《海洋学报(英文版)》2021,40(11):87-103

In order to satisfy the increasing demand for the marine forecasting capacity, the Bohai Sea, the Yellow Sea and the East China Sea Operational Oceanography Forecasting System (BYEOFS) has been upgraded and improved to Version 2.0. Based on the Regional Ocean Modeling System (ROMS), a series of comparative experiments were conducted during the improvement process, including correcting topography, changing sea surface atmospheric forcing mode, adjusting open boundary conditions, and considering atmospheric pressure correction. (1) After the topography correction, the volume transport and meridional velocity maximum of Yellow Sea Warm Current increase obviously and the unreasonable bending of its axis around 36.1°N, 123.5°E disappears. (2) After the change of sea surface forcing mode, an effective negative feedback mechanism is formed between predicted sea surface temperature (SST) by the ocean model and sea surface radiation fluxes fields. The simulation errors of SST decreased significantly, and the annual average of root-mean-square error (RMSE) decreased by about 18％. (3) The change of the eastern lateral boundary condition of baroclinic velocity from mixed Radiation-Nudging to Clamped makes the unreasonable westward current in Tsushima Strait disappear. (4) The adding of mean sea level pressure correction option which forms the mean sea level gradient from the Bohai Sea and the Yellow Sea to the western Pacific in winter and autumn is helpful to increasing the fluctuation of SLA and outflow of the Yellow Sea when the cold high air pressure system controls the Yellow Sea area.  相似文献   

Effects of tillage management on infiltration and preferential flow in a black soil, Northeast China   总被引：2，自引：0，他引：2  

Ruqin Fan  Xiaoping Zhang  Xueming Yang  Aizhen Liang  Shuxia Jia  Xuewen Chen 《中国地理科学(英文版)》2013,23(3):312-320

The impacts of no-tillage (NT) and moldboard plough (MP) managements on infiltration rate and preferential flow were characterized using a combined technique of double-ring device and dye tracer on a black soil (Mollisols) in Northeast China. The objective of this study is to evaluate how tillage practices enhance soil water infiltration and preferential flow in favor of soil erosion control in the study area. The steady infiltration rates under NT management are 1.6 and 2.1 times as high as those under MP management in the 6th and 8th years of the tillage management in place, while the infiltrated water amounts under NT management are 1.4 and 2.0 times as high as those under MP management, respectively. The depth of methylene blue penetrated into NT soil increases from 43 cm in the 6th year to 57 cm in the 8th year, which are 16 cm and 19 cm deeper than those in MP soil, respectively. The results of morphologic image show that more biological macro-pores occur in NT soil than in MP soil. These macro-pores play a key role in enhancing preferential flow in NT soil, which in turn promotes water infiltration through preferential pathways in NT soil. The results are helpful to policy-making in popularizing NT and have the implications for tillage management in regard to soil erosion control in black soil region of China.  相似文献   

西北太平洋的一种潮汐数值同化模型   总被引：1，自引：1，他引：0  

朱学明  鲍献文  黄必桂  石新刚  靖春生 《海洋学报》2012,34(2):1-12

利用FVCOM海洋数值模式,在球坐标系统下考虑非线性效应和天体引潮力的影响,基于非结构的三角形网格建立了包括中国近海、日本海、鄂霍次科海和部分西北太平洋海域的高分辨率海洋潮汐数值模型,并采用趋近法同化84个沿岸验潮站的观测资料。模拟结果与175个验潮站的实测结果拟合良好,M₂,S₂,K₁,O₁四个主要分潮振幅和迟角的绝对平均误差分别为4.0 cm和5.6°,2.4 cm和7.5°,2.6 cm和6.3°,1.5 cm和5.0°。依据调和分析结果给出了4个主要分潮的同潮图分布,得到8个半日分潮和5个全日分潮的无潮点,证实了宗谷海峡全日潮无潮点的存在,首次模拟得到津轻海峡的全日潮无潮点;还给出了整个计算海域内最大可能潮差和潮汐余水位的分布特征。  相似文献   

大连城市社区宜居性分异特征   总被引：4，自引：0，他引：4  

李雪铭  刘秀洋  冀保程 《地理科学进展》2008,27(4):75-81

当前人居环境宜居性研究主要集中于城市层次,城市社区的宜居性研究较少,研究社区的宜居,是对城市 宜居性评价的深入,可为城市社区规划提供建议和指导。通过调查问卷的形式,对大连市的社区进行调查,充分考 虑评价因子的代表性和多层次性的特点,选取6 项二级指标和24 项单项指标建立评价指标体系;运用主成分分析 法获得社区宜居度偏好图,采用层次分析法与地理信息系统软件Surfer 8.0 相结合的方法, 对大连市社区的宜居度 进行初步评价,借用比奇的分异度指数的概念,参考其对社会阶层的分异研究,最后得到社区宜居性分异度指数为 27.6。研究结果表明:大连市社区的宜居度整体评价较好, 市内四区存在较大差异;宜居度的高值区主要分布于风景 优美的地区,以及商业活动的中心和行政中心所在地等地区。  相似文献