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1.
自然地理要素空间插值的几个问题   总被引:77,自引:8,他引:69  
资源管理、灾害管理、生态环境治理以及全球变化研究的需要强化了部分自然地理要素空间插值研究的重要性。这些要素空间插值的核心是建立充分逼近要素空间分布特征的函数方程。对于给定的区域与要素样本值 ,插值函数可以有多种模型形式。各类模型的精度受其理论基础、模型算法、时空尺度效应、样本数据属性等因素的综合影响。通过对国际主要插值研究成果进行分析 ,文章认为各类模型插值精度的差异缘于模型对插值要素空间变异性与空间相关性的反映 ,具体应用中 ,只有对已知样本数据进行变异性与相关性分析才能选出适当的插值方法。  相似文献   

2.
用传统统计学方法模拟和解释土地利用变化的前提条件是研究分析的数据在统计上必须独立且均匀分布。但是空间数据相互之间通常具有依赖性 (即空间自相关),某一变量的值随着测定距离的缩小而变得更相似或更为不同。由于经典线性回归方法未能抓住数据的空间自相关特征,而空间自相关包含一些有用的信息,为了克服这一缺点,利用Moran的I系数自相关图来描述研究区土地利用变化的空间自相关,并且建立了不仅考虑回归而且又考虑空间自相关的混合回归-空间自相关回归模型 (即空间滞后模型)。研究得到:① 研究区土地利用变化模型中不但自变量之间而且因变量之间存在空间正自相关,这表明土地利用变化数据的空间自相关很强;② Moran的I系数随着尺度的变粗而减小,这是由于数据平均时的滤波特性和Moran的I系数对距离的非线性特征造成的;③ 经典线性回归模型的残差也表现出正相关,这表明标准的多元线性回归模型未能考虑土地利用数据所存在的空间依赖性;④ 混合回归-空间自相关回归模型 (即空间滞后模型) 的残差未存在空间自相关,并且有更好的拟合度;⑤ 相对于经典线性回归模型,混合回归-空间自相关回归模型 (即空间滞后模型) 对于存在空间自相关性的数据来说有着统计上的合理性,而经典线性回归模型未能考虑这些因素。  相似文献   

3.
This study empirically investigates the potential of auditory displays for spatial data exploration, as an additional means to broaden the accessibility and dissemination of geographic information for a diverse body of users. In a mixed factorial experiment, three parameter mapping sonification methods are empirically evaluated to interactively explore discrete and continuous digital elevation models by auditory means. Contrasting prior sonification research, this study’s unique empirical evidence suggests that participants can indeed successfully interpret sonified displays containing continuous spatial data. Specifically, the auditory variable pitch leads to significantly better response accuracy, compared to the sound variable duration. Background and training has a weak effect on data interpretation performance with the auditory display. The more immersive the experienced soundscape, the better participants can interpret the sonified terrain. These encouraging empirical results indeed suggest that interactive auditory displays might offer additional means to disseminate spatial information, and to increase the accessibility to spatial data, beyond the currently dominant visual paradigm.  相似文献   

4.
Spatial variance is an important characteristic of spatial random variables. It describes local deviations from average global conditions and is thus a proxy for spatial heterogeneity. Investigating instability in spatial variance is a useful way of detecting spatial boundaries, analysing the internal structure of spatial clusters and revealing simultaneously acting geographic phenomena. Recently, a corresponding test statistic called ‘Local Spatial Heteroscedasticity’ (LOSH) has been proposed. This test allows locally heterogeneous regions to be mapped and investigated by comparing them with the global average mean deviation in a data set. While this test is useful in stationary conditions, its value is limited in a global heterogeneous state. There is a risk that local structures might be overlooked and wrong inferences drawn. In this paper, we introduce a test that takes account of global spatial heterogeneity in assessing local spatial effects. The proposed measure, which we call ‘Local Spatial Dispersion’ (LSD), adapts LOSH to local conditions by omitting global information beyond the range of the local neighbourhood and by keeping the related inferential procedure at a local level. Thereby, the local neighbourhoods might be small and cause small-sample issues. In the view of this, we recommend an empirical Bayesian technique to increase the data that is available for resampling by employing empirical prior knowledge. The usefulness of this approach is demonstrated by applying it to a Light Detection and Ranging-derived data set with height differences and by making a comparison with LOSH. Our results show that LSD is uncorrelated with non-spatial variance as well as local spatial autocorrelation. It thus discloses patterns that would be missed by LOSH or indicators of spatial autocorrelation. Furthermore, the empirical outcomes suggest that interpreting LOSH and LSD together is of greater value than interpreting each of the measures individually. In the given example, local interactions can be statistically detected between variance and spatial patterns in the presence of global structuring, and thus reveal details that might otherwise be overlooked.  相似文献   

5.
This article develops an innovative and flexible Bayesian spatial multilevel model to examine the sociospatial variations in perceived neighborhood satisfaction, using a large-scale household satisfaction survey in Beijing. In particular, we investigate the impact of a variety of housing tenure types on neighborhood satisfaction, controlling for household and individual sociodemographic attributes and geographical contextual effects. The proposed methodology offers a flexible framework for modeling spatially clustered survey data widely used in social science research by explicitly accounting for spatial dependence and heterogeneity effects. The results show that neighborhood satisfaction is influenced by individual, locational, and contextual factors. Homeowners, except those of resettlement housing, tend to be more satisfied with their neighborhood environment than renters. Moreover, the impacts of housing tenure types on satisfaction vary significantly in different neighborhood contexts and spatial locations.  相似文献   

6.
There exist many facets of error and uncertainty in digital spatial information. As error or uncertainty will not likely ever be completely eliminated, a better understanding of its impacts is necessary. Spatial analytical approaches, in particular, must somehow address data-quality issues. This can range from evaluating impacts of potential data uncertainty in planning processes that make use of methods to devising methods that explicitly account for error/uncertainty. To date, little has been done to structure methods accounting for error. This article develops an integrated approach to address data uncertainty in spatial optimization. We demonstrate that it is possible to characterize uncertainty impacts by constructing and solving a new multi-objective model that explicitly incorporates facets of data uncertainty. Empirical findings indicate that the proposed approaches can be applied to evaluate the impacts of data uncertainty with statistical confidence, which moves beyond popular practices of simulating errors in data.  相似文献   

7.
针对传统空间数据关联规则挖掘缺乏不确定性处理及度量的局限性,将空间数据的不确定性和空间数据挖掘的不确定性有机结合,初步建立了空间数据关联规则挖掘的不确定性处理模型及度量指标,包括空间数据不确定性的Monte Carlo模拟、基于不确定性空间数据的空间自相关度量和关联规则不确定性度量等,并以我国某地区环境调查数据为例进行验证。  相似文献   

8.
Spatial association rule mining (SARM) is an important data mining task for understanding implicit and sophisticated interactions in spatial data. The usefulness of SARM results, represented as sets of rules, depends on their reliability: the abundance of rules, control over the risk of spurious rules, and accuracy of rule interestingness measure (RIM) values. This study presents crisp-fuzzy SARM, a novel SARM method that can enhance the reliability of resultant rules. The method firstly prunes dubious rules using statistically sound tests and crisp supports for the patterns involved, and then evaluates RIMs of accepted rules using fuzzy supports. For the RIM evaluation stage, the study also proposes a Gaussian-curve-based fuzzy data discretization model for SARM with improved design for spatial semantics. The proposed techniques were evaluated by both synthetic and real-world data. The synthetic data was generated with predesigned rules and RIM values, thus the reliability of SARM results could be confidently and quantitatively evaluated. The proposed techniques showed high efficacy in enhancing the reliability of SARM results in all three aspects. The abundance of resultant rules was improved by 50% or more compared with using conventional fuzzy SARM. Minimal risk of spurious rules was guaranteed by statistically sound tests. The probability that the entire result contained any spurious rules was below 1%. The RIM values also avoided large positive errors committed by crisp SARM, which typically exceeded 50% for representative RIMs. The real-world case study on New York City points of interest reconfirms the improved reliability of crisp-fuzzy SARM results, and demonstrates that such improvement is critical for practical spatial data analytics and decision support.  相似文献   

9.
Since the launch of the U.S. Department of Homeland Security in 2002, research needs have been established in the areas of disaster preparedness and critical infrastructure protection. Disaster preparedness seeks to lessen the adverse effects of catastrophes by planning in advance and instituting a proper response. Critical infrastructures are those entities deemed necessary for society to function correctly and thus require protection. Recent studies have used location models to aid in the management of many of these crucial establishments, but few efforts have modeled where to geographically site a future critical supply facility. Furthermore, no research has explored a multihazards approach for siting critical supply facilities and the explicitly spatial factors that make a potential target vulnerable to attack. In this article, we propose a strategic multiobjective modeling framework for siting critical supply facilities that incorporates explicitly spatial disaster preparedness directives and critical infrastructure protection demands. We detail the spatial data requirements and modeling assumptions and present results from an application involving the placement of critical vaccine stores in Orlando, Florida.  相似文献   

10.
空间数据分析技术在公共卫生领域的应用   总被引:19,自引:0,他引:19  
空间数据分析技术是分析具有空间属性的事物之间相互关系,对空间信息进行认知、解释、预测及调控等,而公共卫生研究领域集中在疾病时空规律的认识、成因分析以及干预和防御等领域。本文从公共卫生研究的方向出发,论述了空间数据分析技术在公共卫生领域的应用,以及现阶段空间数据分析软件的发展状况,并对空间数据分析技术在公共卫生领域的应用前景作了展望。  相似文献   

11.
基于市场潜能的城市经济增长空间格局及溢出效应   总被引:4,自引:4,他引:0  
王雪辉  谷国锋 《地理科学》2017,37(11):1617-1623
基于新经济地理学理论,定量分析中国285个地级市的市场潜能及其空间格局,并根据其强度划分为3个等级市场潜能区,运用探索性空间数据分析工具,揭示其空间相关性随地理距离的变化规律。引入市场潜能变量作为测度经济增长溢出效应的指标,建立空间计量模型测度中国经济增长的空间溢出效应及其范围,结果显示:中国市场潜能空间分布呈“中心-外围”结构,具有从沿海向内陆阶梯状递减的趋势;市场潜能的空间自相关性随距离增加先上升后下降,市场潜能的强度不同,其空间自相关范围也有所差异;经济增长溢出效应强度随距离增加呈“∽”型趋势变化,中国地级市经济增长的有效溢出范围为200 km以内,市场潜能越高,经济活动空间集聚性越强,溢出范围越大。  相似文献   

12.
京津冀都市圈经济增长收敛机制的空间分析   总被引:16,自引:4,他引:12  
马国霞  徐勇  田玉军 《地理研究》2007,26(3):590-598
区域经济增长收敛机制研究是近年来区域经济学者关注的热点问题之一。本文采用探索性空间数据分析方法,利用空间自相关模型,从新的视角探讨了京津冀都市圈经济增长的空间依赖关系;基于空间计量经济学方法,通过对传统收敛模型加入空间项构建了空间滞后模型和空间误差模型,进而对京津冀都市圈的区域经济收敛机制进行了实证分析。研究结果表明:京津冀都市圈在1992~2003年经济增长存在收敛趋势,但由于强集聚效应,收敛率较低,内部差异仍很显著。  相似文献   

13.
In a pilot classification of 282 10-km squares in Great Britain, data on physiography, climate and geology were extracted. Parallel classifications were run using these variables and also using spatial location. Two classification methods were compared: minimum within-group variance and indicator species analysis. Similarities between the resulting classifications were considered, and the groups were assessed for geographic coherence. Their validity for use as stratifications were tested using analysis of variance and also by matching the classifications with known distributions of a number of bird and plant species.Classifications using spatial variables were geographically more coherent than those without. The different methods resulted in different groupings of the squares which were partly a result of the differences in weightings applied to the four types of variable. However, the analysis of variance showed that either classification method provided a good stratification of the country, in particular with respect to altitude and rainfall. Some bird and plant species distributions correlated well with the classifications, but others did not, dependent on the factors limiting those distributions.  相似文献   

14.
人口分布影响因素研究有利于揭示人口分布规律,预判人口分布趋势。基于陕西省区县级人口、经济社会、自然地理等数据,通过因子分析方法和空间计量建模解析人口分布的影响因素。研究发现,人口地域别比率不仅取决于一个特定区县内可观测的经济社会、历史基础、自然地理等外在特征,还取决于该区县不可观测的、模型遗漏的其他共有特征,其中经济与公共服务因子、人口基底因子对人口分布具有最显著的正向解释力,其他因素影响较弱或统计不显著;城市等级可显著强化产业结构、人均收入和地形因素对人口分布的影响。研究认为,经济与公共服务因素是优化人口分布的关键,同时需考虑自然地理因素的限制作用。研究对人口分布优化政策的制定具有参考价值。  相似文献   

15.
1.IntrodctionEnvirorun~lehassionsarebyproduCtsofeconoAncadivihes.ThelevelofedrissionsgenerallyincreasesastheleveIOfeconondcaCtivitiesincreases.AsameasureofpollutioninimsihescausedbyeconoAncaedvihes,aneAnssionfaCtorgenerallytakesthefOrmofarati0bforantOtalpollutantquantityandtotaleconohacaCtivity[l],orThenumerator,totalwaSteorpollthentqUantitymaybemeasuredinwegh,orvoIumeor,somedmes,nuybemulhpliedbyahealthriskfaCtor(tokicityindex)0fthepollutant.Thedenondnator,totaleconothecaCtivities,canbe…  相似文献   

16.
珠三角县域城市潜力的空间集聚演化及影响因素   总被引:1,自引:0,他引:1  
运用因子分析、扩展的潜力模型、ESDA和空间计量经济学模型,基于五个时间断面的数据,探讨了1990-2009年珠三角县域潜力的空间集聚格局演变特征及其影响因素。研究发现:总体上珠三角县域潜力具正空间集聚特征,但集聚程度不高且趋于减弱;大多数县域潜力的局部空间集聚特征保持相对稳定且规律性明显,高潜力县域集中在广-佛都市区并呈向深-莞-惠都市区发展态势,低潜力县域进一步向研究区西部集聚,并在西部形成面状连续分布区;局部空间集聚格局也发生了一些变化:HH和LL集聚区位有所变化,局部集聚类型间有一定的转化,县域潜力的空间集聚的不均衡性在西部与中东部地带间有进一步扩大倾向。从县域潜力集聚演化的影响因素上看,县域间相互作用、地理区位、消费者购买力、人力资本、劳动力成本、信息化水平有显著正向影响;企业数量、城市化水平有显著负向影响;交通运输条件、固定资本投入和两个经济政策因素的影响不显著。  相似文献   

17.
叙述了面向“数字城市”多源数据的空间数据立方体空间度量的基本定义;描述了空间度量的聚集概念,并结合具体的图例阐述了点状、线状、面状空间度量的聚集过程;解释了空间数据立方体维上钻、维下翻、维层次上钻、维层次下翻的空间度量聚集操作基本原理。  相似文献   

18.
地理探测器:原理与展望   总被引:261,自引:30,他引:231  
王劲峰  徐成东 《地理学报》2017,72(1):116-134
空间分异是自然和社会经济过程的空间表现,也是自亚里士多德以来人类认识自然的重要途径。地理探测器是探测空间分异性,以及揭示其背后驱动因子的一种新的统计学方法,此方法无线性假设,具有优雅的形式和明确的物理含义。基本思想是:假设研究区分为若干子区域,如果子区域的方差之和小于区域总方差,则存在空间分异性;如果两变量的空间分布趋于一致,则两者存在统计关联性。地理探测器q统计量,可用以度量空间分异性、探测解释因子、分析变量之间交互关系,已经在自然和社会科学多领域应用。本文阐述地理探测器的原理,并对其特点及应用进行了归纳总结,以利于读者方便灵活地使用地理探测器来认识、挖掘和利用空间分异性。  相似文献   

19.
焦方谦  赵新生  陈川 《干旱区地理》2013,36(6):1111-1124
利用空间统计方法进行泥石流易发性定量评价的本质是度量影响因子(地形、地貌、岩性等)和响应因子(泥石流)之间的空间关系,最后给出所有影响因子综合作用结果,得到泥石流易发性评价结果。选取高程、坡度、坡向、地形起伏度、岩性、降雨量与水系距离7个因素作为泥石流影响因子,采用证据权模型,对研究区内泥石流进行灾害易发性评价,使用自然间断法将研究区内泥石流易发程度分级,得到研究区泥石流易发后概率图,获得了较高的置信度,方法简单易行,可以在其它灾害易发性评价中推广。  相似文献   

20.
土地利用/ 土地覆被变化(LUCC) 是当前研究全球变化的重要内容, 而区域土地利用 格局模拟是LUCC 研究的核心内容之一。以张家界市永定区为研究单元, 根据由2005 年土地 利用现状图和数字高程模型数据源得到的土地利用、地形、河流以及道路等空间数据, 对区 域土地利用类型空间格局的空间自相关性特征进行了建模研究, 并通过在传统Logistic 模型 中引入描述空间自相关性的成份, 实现了能够考虑自相关性因素的回归分析模型 (AutoLogistic 模型), 同时应用该模型对区域土地利用格局进行了模拟和分析。结果显示, 通 过与没有考虑空间自相关性的回归模型(传统Logistic 模型) 相比较, 该模型显示了更好的拟 合优度和更高的拟合准确率(耕地、林地、建设用地及未利用地的ROC 值分别从0.851、 0.913、0.877 和0.852 提高到0.893、0.940、0.907 和0.863)。研究结果说明了基于 AutoLogistic 方法的土地利用格局的相关性建模在一定意义上是合理的。同时研究结果也可以 为永定区及其相似地区的土地利用规划决策提供更为科学的依据。  相似文献   

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