A comparison of three image-object methods for the multiscale analysis of landscape structure

Within the conceptual framework of Complex Systems, we discuss the importance and challenges in extracting and linking multiscale objects from high-resolution remote sensing imagery to improve the monitoring, modeling and management of complex landscapes. In particular, we emphasize that remote sensing data are a particular case of the modifiable areal unit problem (MAUP) and describe how image-objects provide a way to reduce this problem. We then hypothesize that multiscale analysis should be guided by the intrinsic scale of the dominant landscape objects composing a scene and describe three different multiscale image-processing techniques with the potential to achieve this. Each of these techniques, i.e., Fractal Net Evolution Approach (FNEA), Linear Scale-Space and Blob-Feature Detection (SS), and Multiscale Object-Specific Analysis (MOSA), facilitates the multiscale pattern analysis, exploration and hierarchical linking of image-objects based on methods that derive spatially explicit multiscale contextual information from a single resolution of remote sensing imagery. We then outline the weaknesses and strengths of each technique and provide strategies for their improvement.     

空间线群目标相似度计算模型研究

以空间线群目标的空间统计特征为基础,对线群目标的空间关系和几何特征进行了描述。利用拓扑关系概念邻域图定义线群之间的拓扑关系相似度,利用方向均值定义线群之间的方向关系相似度以及利用"环形方差"定义线群目标之间的距离相似度。结合线群的长度和平均长度、线群密度及线群曲折度,建立了线群目标相似度计算模型,对线群目标相似度进行了整体度量。实验结果表明,相似度计算结果与地物特征比较一致,符合人们的直观认知。     

基于矩阵论的空间相似变换分析

根据空间相似变换的线性化公式，利用矩阵论分析误差方程的系数矩阵，给出求解空间相似变换参数所需控制点的具体要求。     

Surface description for urban climate studies: A gis based methodology

In order to understand the nature of the urban climate, predict the effects of urbanization, or attempt to ameliorate some of the negative hydroclimatic effects of urbanization, it is necessary to have a good understanding of the role and significance of the urban surface. This paper presents a methodology which uses GIS to represent the characteristics and morphology of the urban surface, which can be used to describe a site objectively, model fluxes, or ensure spatial consistency between measured and modelled data, all of which can vary through time. The methodology is illustrated with respect to Chicago, Illinois. Surface data collected at three spatial scales were used to construct a georeferenced database which was linked to an objective, dynamic accessing system. Spatial variability of surface cover, derived hydroclimatic attributes, and modelled fluxes associated with changes in the urban environment are used to illustrate potential applications of the approach.     

A novel hybrid approach of Bayesian Logistic Regression and its ensembles for landslide susceptibility assessment

Abstract

A novel artificial intelligence approach of Bayesian Logistic Regression (BLR) and its ensembles [Random Subspace (RS), Adaboost (AB), Multiboost (MB) and Bagging] was introduced for landslide susceptibility mapping in a part of Kamyaran city in Kurdistan Province, Iran. A spatial database was generated which includes a total of 60 landslide locations and a set of conditioning factors tested by the Information Gain Ratio technique. Performance of these models was evaluated using the area under the ROC curve (AUROC) and statistical index-based methods. Results showed that the hybrid ensemble models could significantly improve the performance of the base classifier of BLR (AUROC?=?0.930). However, RS model (AUROC?=?0.975) had the highest performance in comparison to other landslide ensemble models, followed by Bagging (AUROC?=?0.972), MB (AUROC?=?0.970) and AB (AUROC?=?0.957) models, respectively.     

顾及空间自相关的地理国情信息统计格网尺度选择——以植被覆盖信息统计为例

统计格网尺度的不同会带来统计结果的差异,如何选择统计格网是地理国情信息统计的重要工作。本文提出了一种顾及空间自相关的地理国情信息统计格网尺度选择方法。采用地理国情普查数据,在50 m、60 m、70 m、80 m、90 m、100 m、250 m、500 m和1000 m几个尺度下,以植被覆盖信息统计为例,利用面积占优法和中心点归属法两种方法分别进行格网化,得到了不同尺度的植被格网数据;计算植被覆盖面积统计误差,分析不同尺度下植被覆盖信息的空间自相关的变化特征,并利用Moran’s I系数差值进行尺度选择,得到了植被覆盖信息统计格网的适宜尺度。以龙沙区和清涧县作为研究区域,结果表明,在地理国情植被覆盖信息统计时,不同地区的格网统计适宜尺度是不一样的,植被覆盖度中低的龙沙区的适宜尺度为100 m,而植被覆盖度高的清涧县的适宜尺度为250 m。     

专业认证背景下误差理论与测量平差基础课程建设探索

近年来,旨在与注册测绘师制度相衔接的测绘地理信息类专业认证开启了我国高校测绘教育改革的新思路。测绘类专业认证的核心是使毕业生的能力达成度目标必须符合专业认证标准的各项要求。课程作为整个教学体系的基本单元,对毕业生各项能力的达成起着基本的支撑作用。误差理论与测量平差基础课程作为测绘工程本科专业的主干课程之一,是培养学生有关工程测绘数据处理基本能力的根本保证。本文结合贵州大学办学实际,讨论了测绘专业认证背景下误差理论与测量平差基础课程的建设问题。     

面向统计应用的数据可视化系统设计

当今社会正处于一个信息爆炸的时代,随着企业信息化技术的发展,除了政府机构、媒体(传统媒体)、企业等提供越来越多的数据以外,新兴的社会化媒体、物联网技术等的应用普遍化、介入人类生活的深入化也是数据量急剧增长的主要原因.这些数据大多以表格的形式存放在数据库内,既枯燥又难于理解.如何才能将这些数据有效地展示出来,帮助用户理解数据,发现潜在的规律,是亟待解决的问题.数据可视化能够将抽象的数据表示成为可见的图形或图像,显示数据之间的关联、比较、走势关系,有效揭示出数据的变化趋势,从而为理解那些大量复杂的抽象数据信息,为企业决策支持提供帮助.本文把大数据时代作为背景,把统计数据作为一个整体研究对象,将可视化技术和可视化表现作为方法手段,对各自进行分类和研究探讨,从而全面地认识数据可视化.     

统计地理空间框架建设的国际经验及对中国的启示

为了更好地整合统计地理空间信息,联合国成立了统计和地理信息整合专家组,目标是推进全球统计地理空间框架的实施.全球统计地理空间框架为各国提供了通用的标准和方法,以促进统计和地理空间信息的整合,并提高了结合空间信息的统计数据的可用性,让统计更好地服务于决策.本文介绍了构成统计地理空间框架五项原则的具体内容和相关国际经验,并分析了国内实施框架的基础条件、有利因素和困难.建议国家统计局在今后的普查和统计调查中,参照全球统计地理空间框架原则,加强统计和地理信息的整合,并提出了具体措施.     

基于GIS空间统计分析的广电收视率评估研究——以北京市广电收视覆盖分析系统为例

本文将GIS空间信息统计分析手段应用于广播电视收视率的评估,以层次分析法为基础进行改进,采用抽样调查的方法确定权重,提出较为合理的基于空间信息统计方法的广电人口覆盖分布模型并加以软件实现。以北京市为研究区域,经导入多个版本人口数据实验,发现这种评估方式较好地修正了传统的仅仅按照面积评估覆盖率的评估模型,对于提高广电行业的信息化管理水平具有一定意义。