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1.
突发性泥沙灾害危险性快速区划方法   总被引:4,自引:3,他引:1  
突发性泥沙灾害危险性区划是防灾减灾工作的重要依据.针对传统区划方法存在周期长、成本高、地域性强、对数据完备性要求高等问题,本文基于快速评估思想提出了突发性泥沙灾害危险性的快速区划方法.该方法在确定区划原则、形式、单元、指标的基础上,通过参照系建立、参照组匹配、邻域估测及邻域合并等步骤进行区域泥沙灾害危险度的判定和区划.本文提出的方法具有快速、高效、实用的特点,且在一定程度上能够弥补因资料不足而带来的区划困难,能够更好地服务于防灾减灾工作.  相似文献   

2.
中国滑坡崩塌危险性区划   总被引:21,自引:0,他引:21  
中国滑坡、崩塌灾害日趋严重,对这两种突发性泥沙灾害进行危险性区划具有重要意义.根据滑坡崩塌发生机理选择危险度的基本指标,建立了基于县市行政区的形成条件数据库和重大灾害数据库.采用突发性泥沙灾害危险性快速区划方法将中国分为高危险度区、较高危险度区、中危险度区、较低危险度区和低危险度区.通过图形的叠加计算,对区划结果与形成条件分布的相关性进行分析.同时采用重大历史灾害分布统计,直接验证了快速区划方法的可靠性.  相似文献   

3.
基于GIS的辽宁省岫岩县泥石流灾害危险性区划研究   总被引:1,自引:0,他引:1  
利用GIS技术,以辽宁省鞍山市岫岩满族自治县为例,针对泥石流灾害研究过程中的不确定性,应用确定因子法对泥石流灾害危险性区划进行研究。基于岫岩县地质灾害调查资料,借助GIS的数字化、空间分析等功能,获得泥石流灾害点分布图及其影响因子图,进而利用叠置分析获得按均一条件单元划分的研究区图。根据确定因子法计算每一数据类对应的CF值,然后采用逻辑回归模型进行分析,建立岫岩县泥石流危险性评价模型,利用该模型进行危险性分析,得到岫岩县泥石流危险性区划图。经过灾害点数据的效果检验,证明本方法能够较好地反映泥石流灾害区域危险性特征。  相似文献   

4.
中国公路地质灾害类型较多,不同区域的灾害危险性区别较大,给灾害防治带来一定困难。根据灾害影响因素和危险性评价指标,采用影响因素叠加法,基于ArcGIS 10.0软件,分别进行滑坡(崩塌)、泥石流等单灾种和公路地质灾害综合危险性评价与空间分析;以公路地质灾害综合危险度为指标,完成中国公路地质灾害危险性区划。研究结果表明:中国公路地质灾害综合危险度处于1.000~8.615范围内,公路地质灾害危险性区划结果与实际公路地质灾害分布状况基本一致;公路地质灾害的极重灾区为武夷山—台湾山区和川滇山地;以图件形式明确公路地质灾害危险性在中国的分异状况,并划分不同等级的危险区,可为三级公路地质灾害危险性区划提供基础。  相似文献   

5.
辽宁省老帽山区是山地灾害严重区、频发区,文章应用层次分析法对灾害区的泥石流灾害诱发因素进行权重分析,认为暴雨是触发泥石流灾害的最主要因素。以南岔河流域泥石流沟为例,评价其危险度,结果与实际相吻合,该方法可以推广到对辽南泥石流其他泥石流沟的危险度评价中。针对泥石流灾害的发生,文章提出了一些措施建议,旨在为防治工作提供一些帮助。  相似文献   

6.
通过野外实际考察,对1994年商洛地区发生的大面积暴雨泥石流的类型、分布、形成条件,以及典型泥石流的流速和流量进行了计算。认为泥石流是山区主要的自然灾害,只有恢复生态环境,加强防治措施,才能减轻泥石流灾害损失,促进该地区国民经济的发展。  相似文献   

7.
中国洪水灾害危险程度空间分布研究   总被引:4,自引:1,他引:3  
在前期中国洪水灾害危险程度区划的基础上,叠加全国GDP密度分布图重新聚类制作出中国洪水危险程度区划图,并将区划由原来的八级改成五级,通过前后两种结果的比较,说明区划时考虑GDP更合理.对区划结果按流域进行了洪水灾害危险程度的空间分布分析,结果表明:中国洪水灾害危险最大的地区主要集中在七大流域,尤其是这些流域的中下游平原区.根据中国水灾年表和前人的分析结果两种方法对结果进行了检验,证明本区划结果基本合理.  相似文献   

8.
牛塘沟为寿江左岸一级支流,近年来频繁发生泥石流地质灾害,尤其以2011年8月20日爆发规模最大,对沟口水磨中学及附近居民的生命财产安全构成了巨大威胁。通过现场勘查分析,总结了牛塘沟泥石流孕灾背景及泥石流发育特征,分析了泥石流的形成条件和成因机制,并在计算泥石流动力学特征参数的基础上进行了泥石流危险性评价。研究表明:汶川地震提供的丰富的松散物源是泥石流发育的主要条件;牛塘沟具备灾害链效应、高频、主支沟群发等典型的震后泥石流特点;危险性评价结果表明,在暴雨频率为10%以上,可能会堵塞寿江,属于高危险性泥石流。  相似文献   

9.
谢奎林  陈兴长  陈慧  唐勤  冯鑫 《科学技术与工程》2023,23(29):12406-12415
单沟泥石流危险性分区对泥石流滩地合理开发利用和灾害精细化管理具有重要意义。目前的泥石流危险性评价大多从孕灾环境入手,无法对泥石流危害范围进行危险性分区。在泥石流危害方式分析的基础上,提出了基于动力过程的单沟泥石流危险性评价方法。研究表明,泥石流的危害能力主要与泥深(H)和流速(V)密切相关,进而提出了以泥深(H)和动量(HV)为分区指标的单沟泥石流危险性评价方法。根据分区指标,将单沟泥石流的危险区划分为高、中、低3个等级;高危险区泥深H≥1.5 m或动量HV≥6 m2/s,低危险区泥深H<0.5 m且动量HV<1 m2/s,其他危险区均为中等危险区。最后,基于提出的评价方法对甘肃舟曲“8·7”特大泥石流进行了危险性分析,验证了方法的可行性和实用性。  相似文献   

10.
工布江达县公路沿线泥石流频发,对公路交通安全和县内各区域经济发展造成严重影响。为研究高海拔地区暴雨型泥石流对公路的危害特征和潜在危险性,同时探索基于FLO-2D模型模拟泥石流的方法在高寒、高海拔、强地质构造地区的适用性,本文运用FLO-2D软件,以西藏自治区工布江达县典型公路泥石流——结底岗村泥石流为例,模拟泥石流泥深、流速等方面的冲淤特征,确定泥石流强度并划定危险性分区评价泥石流危险性。以公路沿线典型泥石流沟危险性的“点评价”为基础,通过分析公路泥石流危险分区以及与受威胁路段之间的拓扑关系,定量评估泥石流危险性,可以合理的预测公路泥石流的影响区域和危害程度,为工布江达县公路泥石流灾害分析、预警以及建设设计和公众疏散计划提供技术参考。  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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