Proximity,subjectivity, and space: Rethinking distance in human geography

This paper critically reviews the current status of the concept of distance in human geography in order to argue that recent experimentally-driven work in construal-level theory offers ample opportunities for recasting distance as a key geographical trope. After analysing the four entangled dimensions of distance revealed by construal-level theory (spatial distance; temporal distance; social distance; and hypothetical distance), the paper articulates this research program from experimental psychology with geographical work on non-representational theory, geographical imaginations/imaginative geographies, learning as a geographical process, TimeSpace theorising, and ontogenetic understandings of space. It is argued that the subjective understanding of distance afforded by construal-level theory can rescue distance from its entrenched association with positivistic geography and spatial analysis.     

The clustered nucleation and growth processes of garnet in regional metamorphic rocks from north-west Connecticut,USA

Serial sectioning and imaging with a flatbed scanner yielded the three-dimensional size and spatial distribution of garnet porphyroblasts in two garnet schists and one staurolite-bearing schist from the Everett Formation, north-west Connecticut. The dominant garnet-producing reaction in all samples was chlorite+quartz=garnet+H₂O. The appearance of staurolite, and additional garnet growth in the staurolite-bearing sample, was due to the reaction chloritoid=garnet+staurolite+chlorite. Statistical measures of garnet spatial distributions, using the pair correlation function (PCF), indicate that garnet crystals are weakly to strongly clustered at length scales between 2 and 10 mm. Such clustered nucleation may reflect minor bulk compositional variations. Covariance measures between garnet size and nearest-neighbour distance, using the mark covariance function (MCF), suggest a very weak correlation between crystal size and nearest-neighbour distance for length scales of 2 mm or less. These statistical data suggest that if diffusional gradients were present around growing garnet crystals, they did not influence nucleation and growth patterns at length scales greater than c. 2 mm. Compositional maps, through the garnet centres, show that the smaller crystals have lower Mn core compositions relative to larger crystals, consistent with progressive nucleation during pro-grade metamorphism. Radius-rate plots calculated from compositional X-ray maps show similar growth rates for garnet crystals of different size, consistent with an interface-controlled growth model for garnet. The presence of minor diffusional gradients around growing garnet cannot be entirely dismissed, but the lack of observable reaction rims, the clustered spatial distribution and the radius-rate data are most consistent with an interface-controlled garnet growth model.     

硅酸盐结构中四面体层立体结构式的表述法

本文创造一个用立体结构式表述四面体层的方法。首先用四面体Ｕ、Ｄ、Ｖ、Ｈ定向符号组合成结构基元或结构单元。其次把它们在二维空间平移交换（包括平移、滑移、旋转—平移、反伸—平移），得出四面体层的基本符号格式。最后在其固定的位置上标出平移变换的距离和方向、四面体层的厚度和层间连接方式，完成四面体层的立体结构式。由于某些架状硅酸盐结构，可看成是四面体层的叠加，因此，用立体结构式也可表述。     

基于多重近似索引的空间距离半连接

为了更有效地解决基于外部近似索引空间距离半连接效率较低问题,提出一种基于多重近似索引的空间距离半连接处理方法.该方法在充分利用多重近似索引结构特征基础上,推导出在半连接处理中的距离和空间对象数量约束关系,并在距离半连接算法中利用这些约束关系进行连接处理,从而减少了进行精过滤处理空间对象的数量.通过实验分析表明,基于多重近似索引的距离半连接算法有效,并且基于多重近似索引比基于外部近似索引的距离半连接效率要高.      

Distance-gradient-based variogram and Kriging to evaluate cobalt-rich crust deposits on seamounts

The spatial distribution of cobalt-rich crust thicknesses on seamounts is partly controlled by water depth and slope gradients. Conventional distance–direction-based variogram have not effectively expressed the spatial self-correlation or anisotropy of the thicknesses of cobalt-rich crusts. To estimate resources in cobalt-rich crusts on seamounts using geostatistics, we constructed a new variogram model to adapt to the spatial distribution of the thicknesses of the cobalt-rich crusts. In this model, we defined the data related to cobalt-rich crusts on seamounts as three-dimensional surface random variables, presented an experimental variogram process based on the distance–gradient or distance–“relative water depth,” and provided a theoretical variogram model that follows this process. This method was demonstrated by the spatial estimation of the thicknesses of cobalt-rich crusts on a seamount, and the results indicated that the new variogram model reflects the spatial self-correlation of the thicknesses of cobalt-rich crusts well. Substituted into the Kriging equation, the new variogram model successfully estimated the spatial thickness distribution of these cobalt-rich crusts.     

基于微博平台的中国城市网络信息不对称关系研究

网络信息空间的空间关系及信息流研究为信息化影响下的地理空间演变研究奠定基础。借助微博这一新兴网络信息传播平台获取中国城市间网络信息联系数据,采用流分析方法呈现城市间网络信息联系的空间格局。研究发现:中国城市网络信息关系呈现出"一超多强"的空间极化不对称格局。网络空间不对称格局与地理距离、经济社会发展水平存在密切关联性,表现为:城市对外网络信息总不对称度与其经济社会发展水平的相对一致性;经济社会发展差距对城市间网络信息不对称程度影响的距离衰减性;城市间网络信息不对称程度与经济社会发展差距的相对一致性;东、中、西部三大地区间网络信息不对称关系与经济发展梯度的相对一致性。     

甘肃定西地区地质灾害危险性评价

识别地质灾害聚集的热点区及驱动力对于区域灾害预警具有重要意义。以甘肃定西地区为研究区,选取坡度、坡向、土地利用等7个评价因子,利用确定系数与逻辑回归耦合模型、空间自相关方法分析地质灾害的空间集聚特征及驱动因素。结果表明:定西地区地质灾害危险性呈现中部高,南北两侧低的特征,其主要受降水、坡向、工程岩组等因子的影响;地质灾害与降水、坡向和工程岩组的空间关系为高高聚集;地质灾害危险性存在较强的空间自相关性,在3 km的空间尺度上呈显著正相关,且随距离阈值增加而降低;距离阈值为5 km时,正相关高高聚集与低低聚集以团块的形式存在,而高低聚集与低高聚集多以零星状分布。研究可为区域地质灾害监测与防控提供参考。     

基于微结构模拟的土体自相关距离分析

土体具有显著的空间变异性,描述土体空间变异性的重要指标是自相关距离。提出基于土体微结构模拟的方法来求解土体的自相关距离。在生成土体的微结构数值模型时,对四参数随机生长法（QSGS法）进行改进,考虑土体的粒径分布信息,使得生成的土体微结构更加合理。改进的四参数随机生长法（MQSGS法）所需的输入参数可以结合土体的扫描电镜试验及粒径分析试验获取。基于生成的土体微结构数值模型,即可计算土体的2点自相关函数,再通过曲线拟合即可求解土体的自相关距离。研究表明：与QSGS法相比,采用MQSGS法生成的土体微结构更加符合自然界的真实土体;基于MQSGS法生成的微结构数值模型计算得到的土体自相关距离略小于QSGS法得出的自相关距离。     

空间关系及其应用

GIS中的空间关系主要描述空间对象之间的各种关系,为GIS的分析提供基本的理论和方法支持。空间关系主要包括距离关系、方向关系、拓扑关系及空间关系相似性等。从空间关系的内涵来讲,空间关系模型应该能够反映目标尺度、人类认知、目标层次、现象的不确定以及随时间变化等特性对空间关系的影响;从数学角度来看,空间关系模型必须是可形式化和可推理的,以方便操作和实现;空间关系从人们认知的角度对空间现象和目标间的关系进行建模,因而在空间数据查询、检索、空间数据挖掘、空间场景相似性评价以及图像理解等应用领域得到了广泛应用。现有GIS模型主要针对二维平面的简单对象、确定的现象进行建模,因而大多数空间关系模型只描述和推理二维平面对象和确定现象的空间关系,三维空间关系、不确定空间关系、复杂目标间的多层次空间关系推理、遥感图像空间关系的抽取、描述与推理将是未来空间关系研究和发展的重要方向。     

基于遥感夜间灯光数据的大连城市用地扩张的空间特征分析

为揭示大连城市用地扩张的空间分布特征,基于DSMP/OLS夜间灯光数据提取1998—2013年大连地域边界,并得到各地区的灯光阈值及地域边界分区统计面积。通过计算不同时期不同区域的城市用地增长景观格局指数,研究该市16年来的城市用地扩张方向、强度和空间景观格局变化,以揭示大连20年来城市用地扩张的空间分布特征。结果表明,城市用地扩张主要集中在沙河口区、中山区和西岗区,并以其为中心向甘井子区、旅顺口区、金州区等区域扩张。城市用地空间格局总体基本稳定,受地理条件、空间距离、经济发展和政策指引等因素的影响,城市用地扩张在不同方向上差异化显著。研究成果可作为大连城市规划的依据。     

干旱区内陆河流域农户生态补偿支付意愿的空间异质性分析

深入开展支付意愿的空间差异和空间效应分析, 对于分区定策、 精准实施生态治理工程、 提高生态补偿实践绩效、 提升治理与保护效果等方面, 有着重要的现实指导意义。在确定影响流域农户支付意愿的主要因素的基础上, 借助多分类Logistic模型分析各因素对农户支付意愿的影响作用, 并通过引入通达距离、 距河道距离分别比较流域农户支付意愿的空间效应, 得到的主要结论包括： 在不考虑距离因素的情况下, 教育程度、 农户类型对于农户支付意愿的影响显著; 在考虑距离因素的情况下, 受教育程度对支付意愿的影响存在“脱钩”现象, 模型3模拟结果显示, 高中群体处于更高支付意愿的发生比为1.044, 而大专群体处于更高支付意愿水平的发生比仅为0.363, 即支付意愿并不会伴随受教育程度的提高而增强; 通达距离与支付意愿表现为先负相关（“距离衰减”现象）、 之后呈正相关（“距离递增”现象）的关系; 距河道距离远近对流域农户的支付意愿呈现明显的“距离衰减”规律。     

Spatial and temporal variability of soil moisture based on multifractal analysis

Based on the experimental data collected from 2002 to 2010 in Jilin province, we performed multifractal analysis to investigate the spatial variability of soil moisture during 9 years from 2002 to 2010 and about 60 days from April 21 to June 21 in 2010, and analyzed the relationship between soil moisture and precipitation. The results showed that the soil moisture was multifractal. It was intermediate variability in the soil sample. From 2002 to 2010, the spatial variation of soil moisture was charactered by long distance in 2004, 2006, and 2009 and short distance in 2002, 2003, and 2008. The spatial variation of soil moisture was charactered by long distance from April 21 to May 11 and late June. It was charactered by short distance from May 11 to June 21. From April 11 to July 1, 2010, the spatial variation of soil moisture was mainly affected by the spatial variation of precipitation. From 2002 to 2010, the spatial variation of soil moisture was mainly affected by precipitation in 2006, 2009, and 2010. The spatial variation of precipitation had little effect on soil moisture during 2002 to 2005 and 2007 to 2008. This study analyzed the multifractal characteristic of soil moisture from the perspective of water resources divisions, which can provide references for soil water resources evaluation and water resources allocation.     

元素空间分布插值方法的对比研究:以铜陵地区土壤中的重金属元素为例

文中以铜陵地区As、Cd、Cu、Pb、Tl、Zn等6种土壤污染元素为例,选取常用且具有代表性的反距离加权法、径向基函数法、普通克里格法、多维分形法4种空间插值方法,进行土壤元素空间插值,并对其结果进行验证分析和评价。各方法均选取最优参数进行插值对比,土壤样本数共372个,其中337个用于插值计算,35个不参与插值计算而用于验证插值结果。对比研究显示,普通克里格法对刻画区域土壤元素的空间分布趋势效果最佳,但其半变异函数模型及参数的优选仍有待进一步研究;多维分形法对刻画土壤元素局部异常和污染效果最佳,但其对土壤元素分布普遍特征的反映仍需深入研究;反距离加权法和径向基函数法对土壤元素分布的空间插值精度一般,但其简单易用、插值最优参数易于选择。     

On counting the number of data pairs for semivariogram estimation

In planning spatial sampling studies for the purpose of estimating the semivariogram, the number of data pairs separated by a given distance is sometimes used as a comparative index of the precision which can be expected from a given sampling design. Because spatial data are correlated, this index can be unreliable. An alternative index which partially corrects for this correlation, themaximum equivalent uncorrelated pairs, is proposed for comparing spatial designs. The index is developed under the assumption that the underlying stochastic process is Gaussian and is appropriate when the (population) semivariogram is to be estimated by the sample semivariogram.     

考虑土参数自相关距离影响的单桩可靠性设计方法

在岩土工程设计中,准确地衡量土层参数的空间变异性决定了设计结构的可靠性和经济性,土参数的自相关距离是反映其空间变异性的一个重要指标。目前对于自相关距离与结构可靠性之间的关系的研究还很不完善。本文以单桩可靠性设计为例,选取工程场地的静力触探试验数据,引入随机场理论描述侧摩阻力和锥尖阻力的分布特征,利用递推平均法计算各地基土层侧摩阻力和锥尖阻力的自相关距离,在描述土层侧摩阻力和锥尖阻力的分布特征时考虑了自相关距离的影响,进一步结合蒙特卡洛法计算单桩的可靠指标。结果表明土参数取值考虑自相关距离的影响后,降低了土参数分布的离散程度,计算的单桩可靠指标更高。在保证桩基安全度的前提下,设计结果能够降低工程成本。     

基于地形分区IDW的复垦排土场土壤养分空间分布

准确掌握土壤养分的空间分布，对于评价复垦排土场土壤质量，并制定相应的复垦措施具有重要意义，但是排土场的复杂地形导致一般插值方法的预测效果较差。以内蒙古锡林浩特盟胜利一号露天矿北排土场为例，采用基于地形分区的反距离权重法对土壤养分（速效氮、速效钾、有效磷和有机质）进行空间插值并与常规反距离权重法和克里金插值法进行比较。结果表明，使用分区反距离权重法插值得到的交叉验证精度均高于克里金插值法与反距离权重法，除此之外，有效磷的R2值为0.22，速效氮的R2值为0.37，速效钾以及有机质的R2值分别为0.34与0.14，同样高于克里金插值法与反距离权重法。插值结果显示，排土场速效氮含量整体由北至南逐渐减少；有效磷含量仅在中心地区稍高；速效钾在研究区东北部含量偏高；土壤有机质在中心地区含量相对偏低。研究成果为露天矿排土场土壤养分评价提供借鉴。      

Modeling 2-D spatial variation in slope reliability analysis using interpolated autocorrelations

This paper deals with slope reliability analysis incorporating two-dimensional spatial variation. Two methods, namely the method of autocorrelated slices and the method of interpolated autocorrelations, are proposed for this purpose. Investigations are carried out based on the limit equilibrium method of slices. First-order-reliability-method (FORM) is coupled with deterministic slope stability analysis using the constrained optimization approach. Systematic search for the probabilistic critical slip surface has been carried out in this study. It is shown that both methods work well in modeling 2-D spatial variation. The results of slope reliability analysis are validated by Monte Carlo simulations. Failure probabilities obtained by FORM agree well with simulation results. It is found that 2-D spatial variation significantly influences the reliability analysis, and that the reliability index is more sensitive to vertical autocorrelation distance than to horizontal autocorrelation distance. Based on this study, failure probability is found significantly overestimated when spatial variation is ignored. Finally, the possible use of the method of interpolated autocorrelations in a probabilistic finite element analysis is suggested.     

Characterizing Fracture Spatial Patterns by Using Semivariograms

Semivariogram is applied to fracture data obtained from detailed scanline surveys of nine field sites in western New York, USA in order to investigate the spatial patterns of natural fractures. The length of the scanline is up to 36 m. How both fracture spacing and fracture length vary with distance is determined through semivariogram calculations. In this study, the authors developed a FORTRAN program to resample the fracture data from the scanline survey. By calculating experimental semivariogram, the authors found five different types of spatial patterns that can be described by linear, spherical, reversed spherical, polynomial I (for a<0) and polynomial II (for a>0) models, of which the last three are newly proposed in this study. The well-structured semivariograms of fracture spacing and length indicate that both the location of the fractures and the length distribution within their structure domains are not random. The results of this study also suggest that semivariograms can provide useful infor     

Observed correlations between aftershock spatial distribution and earthquake fault lengths

We observe the spatial distributions of the magnitude of aftershocks following the six earthquakes of focal depth shallower than 20 km with magnitude more than 5.0 from 1983 to 1987 in Japan. The upper limit of the aftershock magnitude is examined as a function of the distance from mainshock hypocentre. The observed spatial distributions of the upper limit are bimodal, with a tendency of the upper limit to decrease as the distance from mainshock hypocentre increases. Moreover, we observe the correlations between the aftershock spatial distribution and earthquake fault length. We focus on the largest aftershocks in each of two aftershock sequences constituting the bimodal distribution. The distances of the two largest aftershocks from the mainshock hypocentre are equal to the fault lengths of shallow earthquakes in Japan and to the maximum earthquake fault lengths.     

Topographic controls on vegetation index in a hilly landscape: a case study in the Jiaodong Peninsula, eastern China

This study examined topographic influence on spatial and temporal variability in the normalized difference vegetation index (NDVI) derived from the Satellite Pour l’Observation de la Terre-Vegetation at the regional and landscape scales in the Jiaodong Peninsula. The generalized additive models were used to quantify the spatial variation of NDVI attributable to local terrain and topographically related variables including altitude, exposure to incoming solar radiation, topographic wetness index, distance to the nearest stream and distance from the coast. NDVI distribution shows significant dependence on topography. The variables explained 38.3 % of variance in NDVI at the peninsula, and 30–45.3 % of variance in NDVI at the woodland, cropland, and grassland landscapes. At the Jiaodong Peninsula scale, NDVI is influenced primarily by distance from the coast. However, topographic wetness index has the most explanatory power for NDVI at the woodland, cropland, and grassland landscapes. Through a statistical nonparametric correlation analysis (Spearman’s r), the study indicates that spatial distribution of NDVI changes during the period 1998–2009 and future change trend of persistence determined by Hurst exponent is closely associated with topography and topography-based attribution. These results highlight the importance of topographic changes at landscape and regional scales as an important control factor on NDVI patterns.