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作为一个多准则评价的相对较新概念,基于GIS的OWA方法可以通过权重计算产生多种决策策略。分析了OWA方法与布尔决策和权重线性叠加(WLC)等多准则评价方法在决策策略上的区别,介绍了依据次序重要性来计算次序权重和应用层次分析程序(AHP)构建比较矩阵来计算准则权重的方法,并应用于唐山市防灾规划,计算了唐山市地质灾害影响下的土地利用适宜度。在分析计算结果的基础上,为唐山市土地资源的合理开发提出了建议。  相似文献   

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传统地磁图适配性分析仅将单一特征参数作为评价指标,从而导致分析结果不全面.针对此问题,提出了一种基于模糊决策理论的地磁图适配性分析方法.首先采用地磁标准差、粗糙度、相关系数、坡度标准差及地磁信息熵等5个主要特征参数作为模糊指标进行加权分析,得到综合评价值以评定候选区适配性.然后基于地磁异常的无迹卡尔曼滤波算法,选取中国...  相似文献   

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In this paper, GIS-based ordered weighted averaging (OWA) is applied to landslide susceptibility mapping (LSM) for the Urmia Lake Basin in northwest Iran. Nine landslide causal factors were used, whereby the respective parameters were extracted from an associated spatial database. These factors were evaluated, and then the respective factor weight and class weight were assigned to each of the associated factors using analytic hierarchy process (AHP). A landslide susceptibility map was produced based on OWA multicriteria decision analysis. In order to validate the result, the outcome of the OWA method was qualitatively evaluated based on an existing inventory of known landslides. Correspondingly, an uncertainty analysis was carried out using the Dempster–Shafer theory. Based on the results, very strong support was determined for the high susceptibility category of the landslide susceptibility map, while strong support was received for the areas with moderate susceptibility. In this paper, we discuss in which respect these results are useful for an improved understanding of the effectiveness of OWA in LSM, and how the landslide prediction map can be used for spatial planning tasks and for the mitigation of future hazards in the study area.  相似文献   

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首先,从空间认知语言学的角度研究了空间关系自然语言描述中谓词、量词等的分类方法;然后,在分析空间查询语言特点的基础上建立了自然语言空间查询的4类句法模式;最后,设计了一个基于自然语言空间关系的空间查询系统框架,并进行了初步实现。  相似文献   

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In this work we propose an approach for mapping flooded areas from Sentinel-2 MSI (Multispectral Instrument) data based on soft fuzzy integration of evidence scores derived from both band combinations (i.e. Spectral Indices - SIs) and components of the Hue, Saturation and Value (HSV) colour transformation. Evidence scores are integrated with Ordered Weighted Averaging (OWA) operators, which model user’s decision attitude varying smoothly between optimistic and pessimistic approach. Output is a map of global evidence degree showing the plausibility of being flooded for each pixel of the input Sentinel-2 (S2) image. Algorithm set up and validation were carried out with data over three sites in Italy where water surfaces are extracted from stable water bodies (lakes and rivers), natural hazard flooding, and irrigated paddy rice fields. Validation showed more than satisfactory accuracy for the OR-like OWA operators (F-score > 0.90) with performance slightly decreased (F-score < 0.75) over heterogeneous conditions (e.g. rice fields). The algorithm was applied with no changes and/or tuning to independent sites from the Copernicus Emergency Management Service (EMS) activations to simulate operational conditions. Over these sites, the proposed approach achieved greater, more consistent and robust mapping accuracy compared to traditional approaches based on the segmentation of single input features. Moreover, OWA operators offer an appealing way of combining and aggregating multiple information in decision making by modelling uncertainty in decision process.  相似文献   

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以面目标为例,首先探讨度量空间关系的描述方法,即拓扑谓词+度量参数,建立拓扑谓词与度量参数之间的对应关系;然后从人的认知角度,分析空间关系的自然语言描述,即拓扑谓词+量词,区分模糊量词和临界量词两类量词,并分别用来描述邻近拓扑谓词相互转化过程中的定量变化和定性变化;最后,分析度量参数与量词之间的关联关系,试图建立空间查询中度量空间关系与自然语言空间关系之间的联系,从而更好地应用于空间查询.
Abstract:
Spatial relations between spatial entities can be obtained by two means. One is computed and obtained by spatial data, and the other is obtained by human spatial cognition. So, they are named as metric spatial relations and natural-language spatial relations, respectively. This paper is focused on filling the gap between these two kinds of spatial relations. For this purpose, regions are taken as example, and three steps are included. Metric spatial relations ore first depicted by combining topological predicates with metric parameters, where a mapping is built between the topological predicates and the metric parameters. Second, natural-language spatial relations are represented by combining topological predicates with quantifiers, where quantifiers are differentiated into two types:vague quantifiers and critical quantifiers. They are respectively used to describe quantitative and qualitative change in the process of the transformation between neighboring topological predicates. Finally, the association between metric parameters and quantifiers is further illustrated and analyzed by a questionnaire. With these three steps, the linkage can be built between metric spatial relations and natural-language spatial relations. The proposed methods have been proven to be rational by the performances of spatial query.  相似文献   

8.
基于计算智能的土地适宜性评价模型   总被引:22,自引:2,他引:22  
将计算智能理论引入土地评价领域,构建了一个全新的土地适宜性评价模型。首先基于模糊逻辑和人工神经网络构造了一个模糊神经网络模型,然后采用改进的遗传算法进行训练,能够快速收敛到最优解,对初始的规则库进行修正,形成了一个自学习、自适应的评价系统。  相似文献   

9.
A novel model of land suitability evaluation is built based on computational intelligence (CI). A fuzzy neural network (FNN) is constructed by the integration of fuzzy logic and artificial neural network (ANN). The structure and process of this network is clear. Fuzzy rules (knowledge) are expressed in the model explicitly, and can be self-adjusted by learning from samples. Genetic algorithm (GA) is employed as the learning algorithm to train the network, and makes the training of the model efficient. This model is a self-learning and self-adaptive system with a rule set revised by training.  相似文献   

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1 IntroductionCategoricalmapsrepresentanimportanttypeofdataincorporatedinGISs,whichdepictspatialdis tributionsinformofexhaustive,non_overlappingarealunitsseparatedbyboundarylines.Anassump tionunderlyingconventionalcategoricalmappingistheobject_basedview…  相似文献   

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Definitions of categories in existent geospatial ontologies are an invaluable source of information because they provide us with essential knowledge about concepts and their properties. A closer examination reveals that definitions also contain supplementary linguistic items, which are mainly qualitative expressions, such as quantifiers. This inclusion of modifiers in definitions affects the way values are assigned to the categories’ properties (semantic properties and relations). This paper introduces a methodology for: (1) representing the essence of qualitative information to clarify the identity relations among categories; and (2) assessing their semantic similarity in order to disambiguate the taxonomic structure of existent geospatial ontologies.  相似文献   

13.
Land suitability analysis is prerequisite for sustainable agriculture and it plays a pivotal role in the niche based agricultural planning in mountain regions. In this paper different parameters viz. climatic (precipitation and temperature), topographic (elevation), soil type and land cover/land use have been used in order to perform land suitability evaluation for cereals food-grain crops in Himachal Pradesh using Geographic Information System (GIS). The suitability analysis was performed by digital processing of geo-referenced data (elevation, climate, soil and landcover) and calculating potential production areas by combining different types of geographical data through decision rules framed for each crop in ArcView spatial analyst. Suitable areas have been delineated for cereal crops in the form of land suitability maps. In comparison to the actual area under cereal crops, the possibility of further expansion under each cereal crop was determined. These discriminated areas appear suitable for growing these crops and can be harnessed efficiently for achieving long term sustainability and food security.  相似文献   

14.
土地适宜性评价的模糊神经网络模型   总被引:19,自引:2,他引:19  
基于神经网络来构造模糊系统,建立了土地适宜性评价的模糊神经网络模型;根据神经网络误差反向修正的原理,设计和推导了该模型的学习算法。实验结果表明,该模型应用于土地适宜性评价具有高效、客观、准确等优点。  相似文献   

15.
基于扩展SQL的GIS模糊查询的表达与实现   总被引:5,自引:0,他引:5  
模糊查询通常包含模糊单词和3种算子──语气算子、模糊化算子和判定化算子。通过模糊集合论,可表示这些模糊概念。在此基础上,介绍了一种扩展SQL表达模糊查询,并将其转化为标准SQL加以实现的方法。  相似文献   

16.
针对橡胶种植适宜性评估,基于云理论、粗集理论和模糊神经网络理论,提出了一种适宜度评估模型。该模型将转化的样本数据进行粗集简约,通过模糊神经网络得出评价因子的隶属函数,计算评价等级。研究结果表明,此模型能够科学、快速、准确地分析出橡胶种植最适宜区、适宜区、次适宜区和不适宜区。  相似文献   

17.
Urban growth is the result of physical and human impacts. In this study Cellular Automata (CA) has been used to analyze physical suitability and human forces in urban growth modelling of Maraghe. The multi-temporal satellite imagery, physical suitability and human impacts Layers have been applied to the modelling. In order to evaluate the accuracy of the image classification methods, Fuzzy ARTMAP is compared with Maximum Likelihood Classification (MLC) and Minimum Distance Classification (MDC) methods. The image classification results showed an overall accuracy of 93 %. Therefore, it is employed for classification of multi-temporal satellite imagery. In order to weight physical suitability and human impacts layers or geographical transition rules in the modelling, regression analysis, the correlation coefficient, trial-and-error method and visual comparison used. The statistical methods are presented to validate neighbourhood scales in the urban growth modelling. The calibration of the model is in fact to the estimate value of the physical suitability and human impacts layer (combinatory layer of demand for urban land and the government facilities) in the modelling. The results obtained from the model calibration showed that human impacts have the highest influence in the urban growth among other factors. Also a small neighbourhood scale (25:5?×?5 cells) is more realistic in the modeling. The accuracy of final validation is 83 % and the final scenario is based on this validation. A fuzzy CA has been used in urban growth modeling of Maraghe. The final scenario shows that Maraghe will growth on the east side, where the land demand for built up area and government facilities plays the significant role.  相似文献   

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 This paper presents a spatial decision support tool that implements the Ordered Weighted Averaging (OWA) method. OWA is a family of multicriteria evaluation operators characterised by two sets of weights: criterion importance weights and order weights. We propose a highly interactive way of choosing, modifying, and fine-tuning the decision strategy defined by the order weights. This exploratory approach to OWA is supported by a graphical representation of the operator's behaviour in terms of decision risk and tradeoff/dispersion between criteria. Our prototype implementation is based on the CommonGIS software, and thus, Web-enabled and working with vector data. We successfully demonstrate online, exploratory support of spatial decision strategies using a data set of skiing resorts in Wallis, Switzerland. Received: 24 September 2002 / Accepted: 10 January 2003  相似文献   

19.
Measurements of water pressure beneath Trapridge Glacier, Yukon Territory, Canada show that the basal water system is highly heterogeneous. Three types of behaviour were recorded: pressure records which are strongly correlated, records which are strongly anticorrelated, and records which alternate between strong correlation and strong anticorrelation. We take the pressure in bore-holes that are connected to the evacuation route for basal water as the forcing, and the other pressures as the response to this forcing. Previous work (Murray and Clarke 1995) has shown that these relationships can be modelled using low-order nonlinear differential equations optimized by inversion. However, despite optimizing the model parameters we cannot be sure that the final model forms are themselves optimal. Computational intelligence techniques provide alternative methods for fitting models and are robust to missing or noisy data, applicable to non-smooth models, and attempt to derive optimal model forms as well as optimal model parameters. Four computational intelligence techniques have been used and the results compared with the more conventional mathematical model. These methods were genetic programming, artificial neural networks, fuzzy logic and self-organizing maps. We compare each technique and offer an evaluation of their suitability for modelling the pressure data. The evaluation criteria are threefold: (1) goodness of fit and an ability to predict subsequent data under different surface weather conditions; (2) interpretability, and the extent and significance of any new insights offered into the physics of the glacier; (3) computation time. The results suggest that the suitability of the computational intelligence techniques to model these data increases with the complexity of the system to be modelled.  相似文献   

20.
Identification of suitable site for urban development in hilly areas is one of the critical issues of planning. Site suitability analysis has become inevitable for delineating appropriate site for various developmental initiatives, especially in the undulating terrain of the hills. The study illustrates the use of geographic information system (GIS) and multicriteria evaluation (MCE) technique for selection of suitable sites for urban development in Mussoorie municipal area, Dehradun district, Uttarakhand. For this purpose Toposheet and IKONOS satellite data were used to generate various thematic layers using ArcGIS software. Criteria using five parameters, i.e. slope, road proximity, land use/land cover, land values and geological formation were used for site suitability analysis following land evaluation. The generated thematic maps of these criteria were standardized using pairwise comparison matrix known as analytical hierarchy process (AHP). A weight for each criterion was generated by comparing them with each other according to their importance. With the help of these weights and criteria, final site suitability map was prepared.  相似文献   

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