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1.
在充分分析韩城市地质灾害调查数据的基础上,采用聚类分析方法对韩城市地质灾害进行风险性评价。首先借助ArcGIS和SPSS软件,抽象出11类地质灾害危险性评价因子和5类易损性评价因子,然后分别基于K平均聚类分析法和系统聚类分析法评价了韩城市地质灾害的危险性和承灾体的易损性,最后根据地质灾害危险性与承灾体易损性的评价结果对韩城市地质灾害风险性进行了评价和分级。研究结果表明,地质灾害风险评价分区结果与实际情况相符,评价方法合理有效,与传统的层次分析和专家打分法相比,规避了人为主观因素的影响,而且操作简单,具有较高效率。该问题的研究能够为地质灾害风险评价提供一定的理论依据和实际指导。  相似文献   

2.
陕西省地质灾害风险区划初步研究   总被引:1,自引:0,他引:1  
省域地质灾害风险区划研究与实践处于起步阶段。在借鉴自然灾害风险的基础上,提出了省域地质灾害风险区划研究思路方法。在地质灾害危险性评价与区划和地质灾害经济社会易损性区划的基础上,采用GIS平台,进行了陕西省地质灾害风险区划初步研究,得到了陕西省地质灾害风险区划初步结果。研究表明:陕西省地质灾害风险区可以划分为高、中、低和极低4级风险区,其中高中风险区15个,面积约占陕西国土面积的35%。这些风险区应成为今后地质灾害防治的重点。  相似文献   

3.
基于GIS的多灾种耦合综合风险评估   总被引:4,自引:0,他引:4  
为了解决多灾种耦合的风险评估问题,应对日益严峻的防灾减灾工作,该文提出了针对自然灾害和事故灾难耦合的风险评估方法。首先,确定评估的单一事件类型,分析致灾因子的强度和概率;其次在地理信息系统平台上将灾害的空间信息进行叠加,得到叠加的危险源分布;再次,对目标区域的易损性信息进行评估;然后将叠加的危险性与易损性分级,通过重分类生成的等级值评估风险;最后根据事件链耦合关系矩阵确定危险源耦合评估结果。选取北京市为研究对象,应用该方法开发了北京市综合风险评估与区划系统。案例研究结果表明:该方法在城市多灾种耦合综合风险评估中具有可行性,有助于管理者对区域风险进行决策和控制。  相似文献   

4.
本文根据地质灾害危险性评估工作的特点,进一步提出地质灾害危险性评估中评价人在项目评估过程中应注意的一些问题,以便规避地质风险和指导生产,更好地促进评估工作的发展。  相似文献   

5.
新平县地质灾害风险评估及架构   总被引:1,自引:0,他引:1  
地质灾害风险评估是从国外引进的新理念和新方法.国内目前对此的理解和应用,经常有概念混淆之处,对其评价也有诸多困难.根据当今国际上通用的地质灾害风险评估理论,以新平为例,综述了国内外在这些难点上进行量化和评价的技术方法,架构了风险评估系统.  相似文献   

6.
鄂西山区处于全省地质灾害高易发区,灾害频发,风险呈现加剧之势。以恩施州巴东县野三关集镇为研究区,通过以斜坡为单元地质灾害调(勘)查工作,归纳了孕灾地质条件,并构建了斜坡地质灾害风险评价体系:首先基于斜坡单元进行评价单元划分;然后采用层次分析法,选取斜坡坡度、斜坡高差、剖面曲率、工程地质岩组、地质构造、斜坡结构、水系密度、植被覆盖率等8个评价因子,对区内斜坡地质灾害易发性进行评价研究;综合考虑人类工程活动和降雨的诱发影响,进行不同降雨重现期工况下危险性区划;根据研究区人口、建筑、道路、土地等承灾体分布,分别进行人口和经济易损性评价;最后根据危险性和易损性评价结果,进行地质灾害风险评价,为野三关集镇发展规划、精细化“隐患点+风险区双控”体系建设提供了理论依据和实际指导。结果表明:随着降雨量的增加,高风险区和极高风险区的面积逐渐增加,主要集中分布在研究区东北片区,针对极高、高风险区地质灾害隐患点和有变形迹象的斜坡建议采取工程治理或专业监测措施,制定应急预案。  相似文献   

7.
洪涝灾害作为自然灾害的重要险种之一,严重影响了人类的生产生活.根据自然灾害风险评估理论,以重庆市为研究对象,从洪灾危险性、敏感性和易损性3个角度出发,选取降水、地形、植被指数、单位面积GDP等8个评价要素指标,以县级行政区划作为评估单元,利用GIS空间分析功能对重庆洪灾进行综合风险评估,结果表明,洪灾危险性、敏感性和易损性均表现出较为明显的空间地域特征,危险性呈由西向东逐级递增的特点,峰值集中在渝东南和渝东北的两翼地区;受地形、河网密度和植被指数综合影响,洪灾敏感性指标分布与长江干流流向体现出了高度的空间相关性,峰值集中在长江干流沿岸的永川、江津、江北、涪陵、垫江等区县;而易损性指标则基本上与重庆市社会经济发展空间分布相吻合.综合来看,研究区洪灾风险等级整体呈现出由西向东减小的趋势,经济较发达的主城、渝西地区风险等级较高,经济欠发达的渝东南、渝东北地区风险等级较小.  相似文献   

8.
辽河三角洲是海平面上升的主要脆弱区.在国内外研究的基础上,运用GIS技术构建海平面上升灾害风险评估的框架体系,对盘锦市进行评估;运用MapInfo软件处理图像资料及社会经济统计数据,获得地面 1 km×1 km范围高程值以及评估单元基础数据;分别按照考虑抗灾能力以及不考虑抗灾能力两种情况,运用海平面上升灾害风险评估模型融合海平面上升灾害危险性、土地系统易损性、社会生态经济易损性和抗灾能力各因子,得到盘锦市海平面上升灾害综合风险评估图,并提出相应对策建议.  相似文献   

9.
小面积大比例尺的城镇地质灾害风险评价研究一直是地质灾害风险评价研究领域一大难点,选取典型山区城镇作为研究区,基于无限斜坡模型,采用斜坡单元尺度,开展不同降雨工况条件下的地质灾害风险定量评价。在获取研究区精细化的调查数据和雨量数据的基础上,通过皮尔逊模型曲线,查询获得研究区不同降雨工况条件下的设计雨强。随后利用Green-Ampt模型中的非积水入渗部分公式计算不同降雨工况条件下的入渗深度,完成模型参数的赋值。基于ArcGIS平台,将完成赋值的参数图层代入无限斜坡模型对斜坡单元的危险性进行逐坡评价。再将不同工况条件下的危险性评价结果与研究区的易损性评价结果叠加,形成不同降雨工况条件下斜坡单元尺度的风险性评价结果。通过复核验证,本文论述的评价方法在小面积大比例尺的城镇地质灾害风险评价研究具有较高的评价精度,具备可操作性和合理性。  相似文献   

10.
目的 了解宝鸡市地质灾害风险的高低程度,分析宝鸡市地质灾害风险区分布规律,为该地区经济建设提供借鉴。方法 以宝鸡市县域单元为研究对象,选取高程等10个指标,运用层次分析法进行危险性评价,选取人口密度等5个指标,运用模糊综合评判法进行易损性评价,进而在危险性评价和易损性评价的基础上,开展基于县域尺度的宝鸡市地质灾害风险评价。结果与结论宝鸡市地质灾害高风险区共798 km2(4.41%),位于金台区、渭滨区南部以及扶风县北部和南部。中风险区共1 244 km2(6.87%),主要位于渭滨区和扶风县中部。低风险区共4 550 km2(25.11%),主要位于眉县、岐山县、太白县和凤县南部。极低风险区共11 525 km2(63.61%),主要分布在陈仓区、陇县、千阳县、麟游县、凤翔区西南部以及凤县和太白县北部。宝鸡市地质灾害中高风险区主要分布在中部和东部地区,西部、南部和北部地区风险较低。该结果可为宝鸡市防灾减灾提供一定参考。  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.
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   

13.
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   

14.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

15.
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   

16.
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   

17.
本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。  相似文献   

18.
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   

19.
20.
The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to  相似文献   

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