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1.
为了实现蓄滞洪区内各洼淀实时洪水调度,考虑到蓄滞洪区内复杂河网与洼淀交错的情况,建立了河道、滞洪区联合计算的一、二维衔接洪水演进数学模型,在考虑铁路、公路、堤防及桥涵等阻水建筑物等复杂边界条件下,采用有限体积法进行离散和求解。结合蓄滞洪区实时洪水调度仿真系统的总体框架,建立了模拟洪水在蓄滞洪区内任意位置的水位、流速、淹没水深、历时等演进过程的一、二维洪水演进数值仿真系统。结合大清河实测资料对东淀滞洪区洪水演进进行了模型验证,结果基本吻合,并应用该系统对大清河滞洪区五洼联合调度方案进行了实时模拟,分析了洼淀联合调度下出现的倒淀现象,对不同方案进行了比较分析,实现了实时的洪水调度分析。  相似文献   

2.
提出了具有旁侧出流的河网独立计算的一、二维多口门嵌套衔接模式,建立了一维河道嵌套于平面二维永定河泛区洪水演进水流数学模型.结合历史调查洪水资料对永定河泛区洪水演进进行了模型验证,二者结果基本吻合.应用该模型对永定河泛区洪水调度方案进行了模拟,先后模拟了无机场、机场近期建设后和远期建设后3种工况下的洪水演进过程.分析对比机场建设前后各分洪区洪水位、滞洪量、淹没范围的变化.模拟结果显示,各分洪口门启用时间稍微提前,机场建设区寺垡辛庄口门启用次序稍有变化,水位的雍高、分洪量的增量、淹没范围的变化对泛区洪水调度方案影响较小,表明了机场建设的可行性.该研究为淹没区的洪灾损失评估及相应的防洪调度方案修订提供了必要的参数和依据.  相似文献   

3.
河道、滞洪区洪水演进数学模型   总被引:1,自引:0,他引:1  
采用有限体积法建立了适应河道、滞洪区复杂情况的洪水演进一、二维衔接数学模型构造了适合河道洪水计算的一、二维河道型网格和滞洪区二维地面型网格,网格具有多点、多面,既镶嵌又衔接的特点阻水建筑物对洪水演进速度影响较大,所以,将其模化成特殊通道,提出了洪水演进过程中渗流所造成的水体损失的计算模式.将该模型应用于大清河滞洪区,讨论了洪水边界条件,确定了模型糙率,率定了模型渗流参数.结合大清河“96.8实测洪水资料”进行了洪水演进数值模拟,分别对河道的水位、流量和滞洪区来水时间进行了模型验证,验证结果基本吻合.  相似文献   

4.
基于一、二维非恒定流基本控制方程,建立了蓄滞洪区洪水演进数学模型.模型采用具有旁侧出流的河网独立计算的一、二维多口门嵌套衔接模式,将一维河道嵌套于二维分洪区中.通过混合编译方法实现了该模型的可视化驾驭功能.介绍了驾驭式模型的基本结构,讨论了该模型混合编译的不同实现方法的优缺点,提出了在保留计算模型独立性和完整性前提下具有通用性的可视化驾驭模型快捷建立方法.结合历史洪水资料,模拟了永定河蓄滞洪区百年一遇洪水演进过程.实现了模拟过程中对各分洪区口门开关和堤埝突发决口事件的监控.  相似文献   

5.
根据长江中游的实际特点,选择汊点分组解法求解河网矩阵方程,克服大型复杂区域内模型计算速度和整体性之间的矛盾。选择水文学-水力学模拟技术相耦合的集成措施,解决洪水调度中下边界难以确定的困难,在此基础上建立了洪水调度数学模型。模型在不同来水条件下均能取得较好的洪水调度模拟效果,能够根据调度原则,给出任意位置水位流量、蓄洪区进出洪量等详细信息,为防洪决策提供参考。  相似文献   

6.
随着我国经济的发展,蓄滞洪区的开发和建设越来越受到人们的关注,对滞洪区进行洪水演进数值模拟研究非常必要.本文采用有限体积法建立了二维洪水演进数学模型,并对洪水演进的水量平衡计算模式进行改进,提出单元水量出流修正法,消除了有限体积法单元体内出现负水深,产生虚假流动的现象.将该研究成果应用于小清河滞洪区洪水演进的数值模拟,采用实测资料,对小清河滞洪区50年一遇洪水演进进行验证和模拟,从而得到泛区内洪水形势及淹没情况,为滞洪区分洪调度提供理论指导.  相似文献   

7.
以荆江分洪区为研究对象,依据长江荆江河段水文气象条件,运用MIKE FLOOD建立了长江枝城-监利河段一维河网模型、荆江分洪区二维水动力学模型以及河网与分洪区一、二维耦合计算模型,模拟了不同频率设计洪水条件下分洪区因堤防溃决而被动分洪的情形,分析了数种风险要素及可能遭灾的地区及受灾程度.结果表明,模型能较好模拟荆江分洪区内洪水演进过程,能较好地预测洪水致灾情况并指出危险区域,可为荆江分洪区的洪水风险管理和避洪转移工作提供科学依据.  相似文献   

8.
基于GIS的洪水淹没场景三维可视化研究   总被引:1,自引:0,他引:1  
通过对研究目标的可视化需求分析,对研究区域开展了包括流域三维地形仿真、洪水演进模拟的三维可视化研究,揭示洪水的运动规律.以GIS技术为基础,基于二维浅水方程,采用有限体积法,建立洪水演进数学模型,并将其制成动态链接库,通过编程调用该库实现洪水淹没分析功能,计算出给定水位下的洪水淹没面积和水量;采用面向对象的编程语言C#,结合ArcEngine组件库,开发了黄河东平湖洪水淹没场景三维可视化系统,并成功应用于东平湖蓄滞洪区的洪水计算中.  相似文献   

9.
长江防洪系统实时洪水调度仿真模型研究   总被引:2,自引:0,他引:2  
根据长江流域防洪系统问题,以“先泄、后蓄、再分洪”为洪水调度原则,进行实时调度仿真模拟,并以长江流域1954年洪水为实例进行模拟验证。模型应用结果表明:应用信息反馈技术实施防洪系统实时调度时,将网络调度模型中节点之间的传播时间融合到网络时空结构中,调整了网络结构,减少了迭代次数和算时,且在网络结构中便于考虑上下游水库蓄放水时间空间差异的协调配合;宜昌至汉口的洪水演进由原来3段分为6段,从而计算精度得到提高。  相似文献   

10.
HEC-RAS系列模型在洪水演进模拟中的应用研究   总被引:2,自引:0,他引:2  
HEC-RAS(River Analysis System)模型是由美国陆军工程师团开发的一款模型,利用该模型可以进行河网的一维水力学演进模拟.模型所需要的河网几何资料可以由HEC-GeoRAS生成.介绍了利用HEC-RAS进行河网洪水演进计算的原理与流程,以及利用HEC-GeoRAS构建河网几何资料的原理和流程.作为实例,利用HEC-RAS与HEC-GeoRAS对南四湖下级湖进行建模,并利用模型对次洪模拟,结果表明模型对于南四湖是适用的.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

15.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

16.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

17.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

18.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

19.
Quality traits in wheat (Triticum aestirum L.) were studied by quantitative trait locus (QTL) analysis in a recombinant inbred line (RIL) population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross (ChSh). Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.  相似文献   

20.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

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