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1.
针对水库建设过程中极易发生的库岸塌岸、滑坡等地质灾害,提出了适当的评价指标并确定了权重和隶属度,采用模糊评价方法对库岸塌岸、滑坡等地质灾害进行了稳定性评价.基于ArcGIS平台的AE组件,采用Visual Studio 2008开发语言C#构建了库岸稳定性评价系统,实现了库区基础地质信息的显示、浏览和库岸塌岸、滑坡等地...  相似文献   

2.
针对传统的滑坡灾害易发性评价中仅考虑评价因子间的一级指标权重或者因子各分级状态的二级指标权重,未能考虑各评价因子各分级状态的综合权重,从而导致评价结果缺乏一定适应性问题。文中提出了将随机森林模型(Random Forest,RF)和确定性系数模型(Certainty Factor,CF)相耦合的加权确定性系数评价模型(Weighted Certainty Factor,WCF)。该模型通过CF模型计算二级指标因子权重,并利用RF模型计算出一级指标因子权重,然后通过将所有指标因子的易发性指数进行加权求和,获得多种因素耦合下的滑坡灾害易发性程度。以陕西省西安市周至县为研究区,在对研究区的地质环境、人类活动情况、滑坡分布特征及形成条件进行了综合分析的基础上,选取了14类与滑坡发生相关的指示因子,结合GIS的空间分析功能,分别采用CF,RF和WCF模型对研究区内滑坡灾害易发性进行区划,各模型的评价结果采用Kappa系数进行对比验证。研究结果表明:研究区内的滑坡主要受高程、地貌类型、与断层距离因子的影响,各因子所占权重分别为0.27,0.12,0.11;改进后的WCF模型区划结果的准确性相对于RF和CF模型提高了5.2%和9.9%.由此表明,WCF模型更适用于研究区的滑坡易发性评价,评价结果可为研究区的滑坡灾害防治规划提供重要的参考价值。  相似文献   

3.
我国自然地质和气候条件复杂,滑坡等地质灾害种类多、分布广、发生频繁,给国民经济建设和人民生命财产造成了巨大损失和不良的社会影响。其中,降雨型滑坡灾害点多面广,危害极大。随着公路网建设的飞速发展,进行公路降雨型滑坡灾害的危险性分区、评价研究至关重要。本文简要地论述了降雨型滑坡灾害的特点,并进行了危险性评价方法、内容的分析,最后提出了一种基于ArcGIS9.1的区域公路降雨型滑坡灾害的危险性评价方法。  相似文献   

4.
改进层次分析法的滑坡灾害危险性   总被引:1,自引:0,他引:1  
对滑坡的危险性进行评价并提出防治措施能有效的减缓滑坡灾害带来的损失.以广东省滑坡危险性评价为例,选取地形地貌、地层岩性、地质构造、岩土体结构、水文地质条件、植被覆盖率、降雨分布、地震以及人类经济工程活动等9个评价因素,通过改进的层次分析法得出因素权重的大小,清楚地显示出主要因素和次要因素.结果表明:地层岩性影响最大,岩土体结构次之,植被覆盖率最小.结果对滑坡的危险性评价提供了更科学、合理的依据.  相似文献   

5.
汉江蜀河水电站属II等大(2)型水电站,水库的运行对库岸的稳定性可能造成一定的影响,甚至诱发库岸失稳灾害,这势必会影响岸坡上铁路的正常运营,所以水库运行对岸坡和铁路路基的稳定性影响必须进行分析评价。文章将影响铁路路基稳定性的因素进行总结分类,利用层次分析法确定权重,在确定各评价指标选择依据和评价标准的基础上,建立了该库岸铁路路基稳定性的二次模糊综合评判模型。  相似文献   

6.
根据典型滑坡的强度指标和可能性指标选取相对高差、坡度、坡体结构、坡型、地层岩性、地层关系、滑坡体积和块石含量等8个评价因子,利用信息熵法、层次分析法与综合权重法分别计算出各评价因子的权重,并对白龙江流域21个典型滑坡进行危险度区划,将3种权重值计算的危险度分级结果进行比较.结果表明:专家权重和信息熵权重危险度分级结果一致率为76%,信息熵权重和综合权重危险度分级结果一致率为86%,专家权重和综合权重危险度分级结果一致率为90%,因此,综合权重得到的危险度分级较其他两种方法更为准确可靠.  相似文献   

7.
三峡库区滑坡灾害众多,防灾减灾工作量巨大,危险性评价是滑坡防灾与减灾工作首要重视的关键内容.本文针对三峡库区特殊地理条件,选取平均坡度、岸坡结构类型等7项14个因素作为三峡库区重点滑坡危险性评价指标,构建评价指标体系.建立针对三峡库区重点滑坡的危险性分级标准.采用层次分析法确定评价因素权重,建立模糊综合评价模型.以三峡库区白家包滑坡为例,详细说明结合层次分析法的模糊综合评价的步骤,其结果与研究区域的滑坡灾情基本相符,并根据评价结果给出防治对策.该案例验证了评价方法的可行性,为滑坡的危险性评价及防灾减灾提供依据.  相似文献   

8.
水库型滑坡主要受库水位升降变化而发生变形,因此对水库滑坡的研究主要集中在库水变动影响下的滑坡变形机理及稳定性分析方面.然而通过对三峡库区滑坡调查发现,有一类水库滑坡变形主要受降雨影响,而研究这类滑坡在降雨和库水共同作用下的变形及稳定性同样具有重要意义.本文以三峡库区某水库滑坡为例,在详细调查该滑坡地质条件及变形发展过程基础上,运用数值模拟方法对其渗流场及稳定性进行了定量分析.结果表明,该滑坡由于特殊的地形条件,其变形主要受降雨影响,受库水位升降影响较小.  相似文献   

9.
从宏观方面,针对滑坡易发性区划,选择高程、坡度、岩性、地质构造、铁路建设和年均降雨量6个致灾因子及其二级指标建立滑坡敏感性区划研究体系,以主客观综合权重方法为原型构建滑坡敏感性区划GP模型,并发布为网络服务,在WebGIS系统中调用该服务自动编制滑坡敏感性区划图.从微观方面,针对单体边坡,使用地理力学方法对边坡的稳定性进行计算与分析.然后根据已有监测数据,运用预测模型,判断滑坡所处阶段,确定滑坡预警级别.该文将地质灾害宏观区划与单体边坡稳定性分析以及监测预警相结合,运用到公路边坡信息管理系统中,从而实现对公路边坡的危险性分析和灾害预警.  相似文献   

10.
基于贡献率模型的汶川县滑坡灾害的易损性评价   总被引:1,自引:0,他引:1  
地质灾害的易损性主要是指受灾体发生损坏的难易程度与遭受地质灾害破坏的机率.贡献率模型是评价作用程度的一种指标模型,它通过贡献率均值化、归一化处理,利用权重转换模型建立贡献率转化的权重关系.以汶川县为例,综合考虑汶川县自身自然和社会经济特点,结合四川统计年鉴(2010年),以及利用GIS技术获取区域地质灾害易损性评价因子时功能约束等条件,选取人口密度、林地密度、耕地密度、滑坡灾害密度、居民点密度、道路密度等6个因子作为汶川县地质灾害易损性评价因子.将汶川县14个乡镇作为基本评价单元,利用贡献率模型进行汶川县滑坡灾害易损性等级区划,划分为5个等级:极高易损区、高易损区、中易损区、低易损区、极低易损区.分析结果显示易损性分布基本上与人口密度、道路密度、林地密度分布相一致,体现了评价结果的合理性.  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.
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   

13.
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   

14.
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   

15.
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   

16.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

17.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

18.
In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.  相似文献   

19.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

20.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

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