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1.
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   

2.
为研究吉林省公路洪水灾害危险性特点,在将吉林省公路地貌划分为平原区和山区的基础上,选取大于25 mm年降水日数、年降水量、地形坡度、区域河网密度和土地利用/覆被类型作为评价指标,分平原区和山区构建吉林省公路洪水灾害危险性综合评价模型,在GIS平台支持下对吉林省公路洪水灾害危险性进行了评价。结果表明,吉林省公路洪水灾害中、低危险区主要分布在吉林省西部和东部的延边朝鲜族自治州中部,较高和高危险区主要分布在吉林省的中部和南部,低、中、较高和高危险区占全省总面积的比例分别为19.91%、25.65%、28.96%和25.48%。  相似文献   

3.
针对丹巴县公路边坡地质灾害频发状况以及区域分布的特点,对丹巴公路边坡灾害进行了危险性分区研究。通过分析自然环境概况与公路地质灾害特征,选取坡度、岩土类型、降雨、河网密度、植被覆盖率和地震6个因素作为地质灾害危险性评价指标体系;采用影响因素叠加法构建危险性评价指数的数学模型,并运用云模型-层次分析法(CM-AHP法)计算各评价指标的权重;基于ENVI 5.2与ArcGIS 10.2软件计算生成《丹巴县公路边坡地质灾害危险指数图》,同时考虑公路工程特点,划分了II低危险区、III中度危险区、IV高危险区和V极高危险区4个等级16个灾害区,依据定量区划范围并结合定性分析的评价方法对丹巴县公路进行地质灾害危险性进行评价。研究结果表明,评价结果与公路边坡灾害实际情况吻合,可为四川省丹巴县公路边坡灾害的预防治理工作提供一种新的途径。  相似文献   

4.
出于山区沿河公路崩滑灾害防治决策的需要,针对山区沿河公路沿线区域崩滑灾害发育的特点,从崩滑灾害孕灾环境和致灾因子两方面对山区沿河公路崩滑灾害危险性进行了综合评价.以地理信息系统和遥感解译为手段,建立崩滑灾害编录和因素基础数据库、遴选评价指标;以历史崩滑灾害面积分布信息熵为基础,计算指标权重;并在统计量化指标崩滑信息指数的基础上,建立了山区沿河公路崩滑灾害危险性评价方法.将该方法用于美姑河省道公路沿线的崩滑灾害危险性评价,结果与研究区实际灾情比较吻合,可为山区沿河公路崩滑灾害减灾决策提供依据.  相似文献   

5.
近年来,孤石滚落灾害越发受到关注,而对其危险性定量评价的相关研究较少。一方面,孤石具有数量多、规模大、形状不一的特点,对孤石群的稳定性判定是一个问题;另一方面,对孤石影响区域的危险性评价是难点。因此以广州市白云山原始森林公园为研究对象,对此区域开展孤石危险性评价。通过孤石稳定性定性定量综合判断+失稳孤石威胁范围精准划分的方法,考虑多评价因子对研究区危险性进行综合评价。利用熵权法计算各评价因子的权重,基于高精度数字高程模型(digital elevation model, DEM)、地理信息系统(geographic information system, GIS)软件和岩石崩落分析(rockfall analysis, RA)软件对研究区危险性等级进行划分,将白云山原始森林公园滚石危险范围划分为4个等级:极高危险区、高危险区、中危险区和低危险区。研究成果提出了一套可为其他区域孤石滚落灾害危险区划参考的系统性评价方法。  相似文献   

6.
针对目前山区丘陵公路边坡危险性评估案例较少,且存在大量模糊性、随机性和不确定性因素等问题,以重庆市某段典型山区丘陵公路为例,结合实地考察情况和专家意见,对该地区公路边坡的影响因子进行深入研究分析,总结归纳了4类14项山区丘陵公路边坡灾害主要影响因子并构建评估指标体系.最后采用AHP-模糊综合评价法实现了该地形公路边坡危险性定量和定性综合评估.结果表明,AHP-模糊综合评价法与赤平投影法的分析结果基本一致,但相比只能进行定性分析的赤平投影法,AHP-模糊评价法可以进行定量和定性综合分析,评估结果更加准确合理,实用性更强.  相似文献   

7.
山区公路排水系统抗水灾评价指标   总被引:1,自引:0,他引:1  
为提高山区公路抗水灾能力,对山区公路排水设施水毁现象进行了调查,并做了机理分析,研究了山区公路排水系统3个子系统单元(坡面漫流单元、排水沟渠单元和小桥涵单元)的组成,建立了山区公路排水系统抗水灾4个递进层次系统(孕灾环境危险性评价、排水系统易损性及完善性评价、水毁经济损失评价、防治效益经济评价)的评价体系,提出了相关经济计算与评价标准.实际应用结果表明,该评价指标体系对山区公路抗水灾养护决策具有明显的指导作用.  相似文献   

8.
为研究地质灾害对国道G345山区路段工程建设的影响,为国道线路设计提供依据,选取地形地貌、岩土体类型、斜坡结构、降水量、河流冲刷程度、地质灾害发育现状6个影响因素,采用模糊综合评判法和信息量法对国道G345镇安金钟至木王林场段公路进行了地质灾害危险性评价,将研究区划分为地质灾害危险性大、中等和小3个区。结果表明:模糊综合评判模型和信息量模型评价结果均与研究区实际情况基本相符,危险性大区和危险性中等区主要分布在路基部分和隧道段。通过与实际情况比较分析,对于地质灾害严重区,模糊综合评判模型优于信息量模型;对于地质灾害较严重区,信息量模型优于模糊综合评判模型。  相似文献   

9.
公路水毁毁损等级划分体系研究   总被引:4,自引:0,他引:4  
在确立公路水毁经济损失评价项目的基础上,提出以公路水毁经济损失总量作为公路水毁毁损等级的评价指标,采用数理统计的方法建立了公路水毁毁损等级划分的两种方法:密度曲线法和相对经济损失法.指明了两种方法的适用情况,并给出了算例.计算结果表明:两种方法均能客观地反映公路水毁毁损的等级,可以为公路管理和养护部门的决策提供依据.  相似文献   

10.
通过对重庆市山洪灾害危险性影响因素进行分析,参考目前山洪灾害危险性分析所选取指标内容,并结合镇域山洪灾害的特点,构建山洪灾害危险性评价体系,应用GIS建立各评价指标的专题图层,利用专家系统评分法给每一危险指标分等赋值以及用层次分析法确定了各评价指标的权重,采用综合评价法得到地区危险性指数;以重庆市巴南区安澜镇为例,通过GIS空间多指标叠加分析得到安澜镇山洪灾害危险性分区图,将定性问题进行定量分析并对其进行评价。  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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