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1.
以福建省顺昌县林地为对象,通过相关性分析,构建顺昌县林地生态脆弱性评价指标体系;采用主成分分析法和综合指数法实现对顺昌县林地生态脆弱性的定量评价,进而分析其生态脆弱性空间分布特征.结果表明:以坡度、土壤K因子、年均降雨量、NDVI和人口密度5个因子作为生态脆弱性评价指标的权重分别为0.195 5,0.140 9,0.119 2,0.302 1,0.242 3;研究区微度脆弱区、轻度脆弱区、中度脆弱区、强度脆弱区和重度脆弱区的面积分别占15.83%,40.92%,24.50%,13.25%和5.50%,整体处于轻度脆弱水平;顺昌县脆弱等级强度以上的区域主要分布在低坡度、低海拔、低植被盖度、人为干扰强度大的区域,是预防山体滑坡和水土流失的重点区域.  相似文献   

2.
荔波退化喀斯特植被自然恢复评价   总被引:1,自引:0,他引:1  
以46个典型样地调查资料为依据,选择与喀斯特植被恢复紧密相关的7个因子构成评价指标,用层次分析法计算各指标的权重值,对植被自然恢复程度进行评价。结果表明:(1)7个因子中群落高度和生物量对植被恢复的影响最大;(2)随着植被恢复由低级阶段向高级阶段发展,恢复程度逐渐增大,至顶极乔林阶段恢复到模式群落的94.12%,这说明群落的结构和功能基本得到了恢复。  相似文献   

3.
洪湖湿地生态脆弱性研究   总被引:3,自引:1,他引:2  
分析洪湖区湿地脆弱性的成因,并采取定量和定性相结合的方法对洪湖区湿地脆弱性进行评价。评价中依据湿地生态特性及演化规律建立评价指标体系,利用层次分析法(AHP)确定指标权重,用综合指数法计算湿地的脆弱度。结果表明:洪湖区湿地的脆弱度为3,属轻度脆弱。该结果对洪湖区湿地资源的合理利用与保护具有指导意义。  相似文献   

4.
针对山东大汶河流域的自然条件及人为干扰状况建立了该流域生态脆弱性评价指标体系,利用地理信息系统软件ARC/INFO空间分析功能,进行主成分分析得到因子权重,提出了生态环境脆弱指数模型,获取了该流域的脆弱度,从而为该流域环境恢复与重建提供科学的依据.  相似文献   

5.
GIS支持下的山东大汶河流域生态脆弱性评价及对策   总被引:6,自引:1,他引:6  
针对山东大汶河流域的自然条件及人为干扰状况建立了该流域生态脆弱性评价指标体系,利用地理信息系统软件ARC/INFO空间分析功能,进行主成分分析得到因子权重,提出了生态环境脆弱指数模型,获取了该流域的脆弱度,从而为该流域环境恢复与重建提供科学的依据。  相似文献   

6.
基于AHP和模糊综合评判法的北疆各地州生态脆弱性评价   总被引:6,自引:0,他引:6  
运用AHP方法,选取13项敏感因子建立北疆地区生态脆弱性评价指标体系并确定了各指标权重;结合AHP和模糊综合评判法,计算了8个地州对各项评价指标的综合隶属度;根据隶属度大小,对生态脆弱性程度分级,得到北疆8个地州的生态脆弱性分级图;最后,分析了各地州生态脆弱性成因和发展对策.计算结果与相关文献记录数据一致,证明该方法兼具2种方法的优点,适用于生态脆弱性评价.本文研究成果也能为北疆地区制定发展策略提供一定的理论依据.  相似文献   

7.
山岳型旅游风景区生态脆弱性评价方法研究   总被引:4,自引:0,他引:4  
就山岳型旅游风景区生态脆弱性评价方法进行了研究,筛选建立了山岳型旅游风景区生态脆弱性评价指标体系,制定了脆弱性评价标准体系,构建了山岳型旅游风景区生态脆弱度计算公式,并根据脆弱度值将山岳型旅游区划分成五个不同的脆弱级别.利用建立的评价方法对长白山旅游风景区生态脆弱性进行了案例研究,得出长白山旅游风景区为高度脆弱级旅游区.  相似文献   

8.
贵州喀斯特生态环境脆弱性类型区及其开发治理研究   总被引:19,自引:0,他引:19  
贵州碳酸盐分布广,喀斯特强烈发育,人类赖以生存的喀斯特环境是一个脆弱的生态系统。本文根据综合性原则,主导因素原则,人地矛盾分析原则和区域完整性原则,从组成生态环境系统的因素入手,采用“灰色关联度”方法,通过指标筛选及权重的确定,求得以县(市)域为单元的生态环境脆弱度。经综合评判,将全省划分为强度脆弱区、中度脆弱区和轻度脆弱区等三大类喀斯特生态环境脆弱性类型区。最后,针对各类型区的基本特征提出了今后开发治理的方向和措施。  相似文献   

9.
AHP法在江西脆弱生态环境评价指标体系中的应用   总被引:2,自引:0,他引:2  
根据区域脆弱生态环境评价指标体系建立的原则,结合本区脆弱性的特点,建立了江西省脆弱生态环境评价指标体系;采用AHP法计算各指标的权重,得到了4个层次的层次单排序。在此基础上,确定了各层次各因子相对的权重,用于评价江西省脆弱生态环境的脆弱程度。结果表明,江西省脆弱生态环境评价指标体系中,目标要素B以人为干扰脆弱(B2)为主,占73%;指标层(D)中20个指标相对应总目标A的权重值排序结果显示,森林覆盖率所占的权重最大,达0.2044,水土流失强度的权重次之,为0.1825,二者占20个指标的比例达39%之多,平均各占19.5%;其他18项指标之和只占61%,平均各占约39%,且单项权重值均小于0.1,足以反映影响江西省脆弱生态环境程度的主导因子是人为干扰脆弱为主,即森林覆盖率和水土流失强度。  相似文献   

10.
喀斯特地区土地生态适宜性评价:以贵阳市为例   总被引:2,自引:0,他引:2  
为寻求促进喀斯特地区城市土地利用与生态系统保护协调发展的方法,在遥感技术和地理信息系统的支持下,以贵阳市为例,综合考虑工程地质、生态环境和社会经济等3个方面11个评价因子,通过Delphi法确定因子分值,利用层次分析法(AHP)计算因子权重,对喀斯特地区土地的生态适宜性进行了综合评价。结果表明:贵阳市建设适宜用地(含建成区)占市域面积4.62%,较适宜用地占19.99%,一般不适宜用地占23.25%,较不适宜用地占23.74%,最不适宜用地占17.71%,不可用地占10.69%。根据评价结果,为不同等级的用地类型提供了相应的建议,为保护喀斯特地区脆弱的生态系统、合理有效地利用土地资源提供了重要依据。  相似文献   

11.
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   

12.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

13.
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   

14.
Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with  相似文献   

15.
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   

16.
17.
The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.  相似文献   

18.
R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).  相似文献   

19.
The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.  相似文献   

20.
Advances in wireless technologies and positioning technologies and spread of wireless devices, an interest in LBS (Location Based Service) is arising. To provide location based service, tracking data should have been stored in moving object database management system (called MODBMS) with proper policies and managed efficiently. So the methods which acquire the location information at regular time intervals then, store and manage have been studied. In this paper, we suggest tracking data management techniques using topology that is corresponding to the moving path of moving object. In our techniques, we update the MODBMS when moving object arrived at a street intersection or a curved road which is represented as the node in topology and predict the location at past and future with attribute of topology and linear function. In this technique, location data that are corresponding to the node in topology are stored, thus reduce the number of update and amount of data. Also in case predicting the location,because topology are used as well as existing location information, accuracy for prediction is increased than applying linear function or spline function.  相似文献   

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