基于可达性测度的公园绿地服务公平性时空分析

由于城区土地资源的稀缺性,公园绿地的供给与人口对绿地的需求往往难以匹配,出现了公园绿地空间分布不均衡和服务不公平性的现象。本文以两步移动搜索法的可达性测度为基础,开展武汉市主城区公园绿地社会公平性的时空分析研究。研究表明:新一轮规划实施后,从服务的整体效益来看,武汉市主城区公园绿地资源分配向着更趋于公平的方向发展;从公园绿地服务的空间格局来看,绿地可达性提高较为显著,可达性极低区域面积减少。     

Biophysical factors of remote sensing approach in urban green analysis

Greenery in an urban environment is an important consideration when studying temperature, and such enquiry can benefit human health. The purpose of this paper is to investigate how ambient temperature in urban areas is affected by forests and parks. The focus is on biophysical parameters related to these green areas, such as impervious surface percentages, albedo, areal coverage, elevation, and leaf area index (LAI). Geographic information systems and remote sensing were used to quantify green spaces using a pixel-based method. It was found that coverage area has little correlation with temperature. Factor analysis was used to determine the minimum number of independent factors, which explained 63% of the variance of that temperature. Only elevation, LAI and albedo were significant biophysical factors. Guidelines for greenery programmes should include these significant data-sets to understand the influence of green areas on heat reduction.     

Ecotourism planning using multiple criteria evaluation with GIS

Hong Kong as an international metropolis is well known for its vibrant urban life, which attracts millions of mass conventional tourists for shopping and business. Recently, ecotourism has flourished and attracts ecotourists who visit the ecological and cultural resources of the rural landscape, country parks and marine parks. Yan Chau Tong, also known as ‘Double Haven’, is remote from the urban centre, which helps preserve its natural flavour and cultural heritages such as Hakka walled villages. It is noted as an important site for developing ecotourist activities. A symbiosis of humans and nature cannot be achieved without a sound planning and zoning scheme. This paper investigates the use of IKONOS imagery and a geographic information system for rational planning of ecotourist activities and conservation measures. Through image classification of IKONOS and integrated with ecological data, essential habitats can be mapped and a spatial database is established. Suitable sites for recreational activities (including camping, heritage visiting, hiking and snorkelling) and important ecological habitats can both be identified using multiple criteria evaluation techniques. The use of a multiple objective land allocation model helps resolve conflict between recreation and conservation. Sites are generally identified as (a) those where conservation or recreation should receive the highest priority; (b) those that can be treated as additional recreation or conservation sites; and (c) conflict areas that can serve both purposes. The result can assist in planning land resources for ecotourism to satisfy both objectives and attain sustainability in the area.     

A Comparative Analysis of Phenological Curves for Major Crops in Kansas

The goal of this research was to conduct an initial investigation into whether a time-series NDVI reference curve library for crops over a growing season for one year could be used to map crops for a different year. Time-series NDVI libraries of curves for 2001 and 2005 were investigated to ascertain whether or not the 2001 dataset could be used to map crops for 2005. The 2005 16-day composite MODIS 250 m NDVI data were used to extract NDVI values from 1,615 field sites representing alfalfa, corn, sorghum, soybeans, and winter wheat. A k-means cluster analysis of NDVI values from the field sites was performed to identify validation sites with time-series NDVI spectral profiles characteristic of the major crop types grown in Kansas. After completing the field site refinement process, there were 1,254 field sites retained for further analysis, referred to as "final" field sites. The methods employed to evaluate whether the MODIS-based NDVI profiles for major crops in Kansas are stable from year-to-year involved both graphical and statistical analyses. First, the time-series NDVI values for 2005 from the final field sites were aggregated by crop type and the crop NDVI profiles were then visually assessed and compared to the profiles of 2001 to ascertain if each crop's unique phenological pattern was consistent between the two years. Second, separability within each crop class in the time-series NDVI data between 2001 and 2005 was investigated numerically using the Jeffries-Matusita (JM) distance statistic. The results seem to suggest that time-series NDVI response curves for crops over a growing period for one year of valid ground reference data may be useful for mapping crops for a different year when minor temporal shifts in the NDVI values (resulting from inter-annual climate variations or changes in agricultural management practices) are taken into account.     

Requirements for Topology in 3D GIS

Topology and its various benefits are well understood within the context of 2D Geographical Information Systems. However, requirements in three‐dimensional (3D) applications have yet to be defined, with factors such as lack of users’ familiarity with the potential of such systems impeding this process. In this paper, we identify and review a number of requirements for topology in 3D applications. The review utilises existing topological frameworks and data models as a starting point. Three key areas were studied for the purposes of requirements identification, namely existing 2D topological systems, requirements for visualisation in 3D and requirements for 3D analysis supported by topology. This was followed by analysis of application areas such as earth sciences and urban modelling which are traditionally associated with GIS, as well as others including medical, biological and chemical science. Requirements for topological functionality in 3D were then grouped and categorised. The paper concludes by suggesting that these requirements can be used as a basis for the implementation of topology in 3D. It is the aim of this review to serve as a focus for further discussion and identification of additional applications that would benefit from 3D topology.     

基于细粒度人口数据的深圳公园绿地可达性评价

公园绿地是城市公共基础设施的重要组成部分,公园合理的空间布局有助于城市居民便捷和公平地享用其服务功能。根据深圳市建筑普查数据和细粒度的人口数据提取住房信息,结合公园绿地数据和土地利用情况,针对不同类型公园的服务能力分别采用合适的可达性计算方法,从住房、社区和街道三个尺度评价深圳公园绿地可达性,结果表明:社区公园可达性一般,仅57.62%的社区的居民步行500 m以内能到达最近的社区公园;城市公园可达性总体较好,95.87%的社区市民步行前往最近城市公园所需时间在20 min以内。然而,大鹏半岛无城市公园,且多为自然生态保护区,市民到达城市公园所需时间长。社区公园可达性好的区域呈带状分布于深圳南部各区,城市公园高可达性区域呈多核围绕在各区行政中心。     

The use of WorldView-2 satellite imagery to model urban drainage system with low impact development (LID) Techniques

Within a wide range of best management practices for stormwater management in urban areas, there has been an increasing interest in source control measures. Source controls such as low-impact development (LID) techniques are potentially attractive as retrofit options for older developed areas that lack available land to implement conventional measures such as stormwater management ponds. Hence, distributed urban drainage models requiring detailed representation of developed drainage areas should be developed to accurately estimate the benefits that LIDs may provide. This study (1) presents a two-stage classification process on a high-resolution WorldView-2 image, and (2) demonstrates how to use the extracted land cover information in the subsequent hydrologic modelling and assessment of different LIDs’ performance. The proposed two-stage classification method achieved an overall accuracy of 80.6%, whereas a traditional pixel-based achieved 68.4% in classifying the same urban area into six land cover classes. From the classification results, the hydrologic properties of micro-subcatchments were imported in the United States Environmental Protection Agency Storm Water Management Model to assess the performance of LIDs. A reduction of run-off volume 18.2% and 37.1% was found with the implementation of porous pavement and bioretention, respectively, in a typical low-rise residential area located in the city of San Clemente, California, US. The study demonstrates the use of high-resolution remote sensing image to aid in evaluating LID retrofit options, and thus benefits in situations where detailed drainage area information is not available.     

多尺度分割的高分辨率遥感影像变化检测

针对高空间分辨率的遥感影像,提出了一种基于多尺度分割的变化检测算法。采用Mean-Shift分割算法对影像进行多尺度分割,构建了不同尺度上的地理对象,以不同尺度上的地理对象灰度均值构建了变化检测的多尺度特征向量,采用变化矢量分析法获得最后的变化检测结果。以城镇区和农田区的Quick Bird影像对本文算法进行了检验,从精度评价的效果来看,无论城镇区还是农田区,采用面向对象的变化检测方法精度都高于基于单像素的检测方法,且当尺度层数固定时,多尺度组合的变化检测结果优于单一尺度的变化检测结果,对城镇、农田区域的变化检测的精度分别达到87.57%和81.55%。本文算法既可以顾及大面积同质区域变化,又可以反映小的地物目标及边缘部分的变化,能够很好地满足城镇、农田等不同环境背景下的变化检测需求,在国土资源监测中具有一定的应用价值。     

The need for psychiatric care in England: a spatial factor methodology

To ensure health resources are equitably distributed, composite indices of population morbidity or “health need” are often used. Measures of the dimensions of population morbidity (e.g. socioeconomic deprivation) relevant to health need are typically not directly available but indirectly measured through census or other sources. This paper considers measurement of latent population morbidity constructs using both health outcomes (e.g. hospital admissions, mortality) and observed area social and demographic indicators (e.g. census data). The constructs are allowed to be spatially correlated between areas, as well as correlated with one another within areas. The health outcomes may depend both on the latent constructs and on other relevant covariates (e.g. bed supply), with some covariates possibly measured only at higher (regional) scales. A case study considers variations in psychiatric admissions in 354 English local authority areas in relation to two latent constructs: area deprivation and social fragmentation.      

Investigating Grazing Intensity and Range Condition of Grasslands in Northeastern Kansas Using Landsat Thematic Mapper Data

Abstract

Grazing changes plant species composition of grassland ecosystems by selective removal and trampling. Grazing also alters soil physical and biogeochemical properties and can dramatically change hydrologic processes that can impact water budgets and quality. For these reasons, practical means are needed to assess grazing management practices and its impacts upon the land. This study examines whether a grazing intensity and range condition gradient can be detected in spectral reflectance characteristics of grasslands in northeastern Kansas. Multitemporal Landsat Thematic Mapper (TM) data, the normalized difference vegetation index (NDVI), and field data collected concurrent with the TM overpasses, were used in the analysis. Correlation analysis was used to examine relationships between spectral data and biophysical data. Next, the study sites within each grassland type were classified into three spectrally similar clusters. Grazing intensity, range condition, and biophysical characteristics were summarized for each spectral cluster and compared.

The results suggest that NDVI may be used as a surrogate for living biomass for both grassland types and may be useful for predicting grazing intensity in native warm season grasslands. And while there appeared to be relationships between total living and non‐living cover, and TM NIR and MIR bands, there were no direct relationships between spectral characteristics and grazing intensity or range condition.     

把基本农田纳入地理国情监测内容的思考

基本农田是“吃饭田”、“保命田”,保护基本农田关乎国计民生、社会稳定,把基本农田纳入地理国情监测内容符合国情需要,也能起到加强基本农田保护的实效性与时效性的作用.本文阐述了把基本农田纳入地理国情监测内容的必要性、可行性,并对监测的内容与方法提出了想法.     

基于GIS的城市空间结构研究进展

城市是包含社会、经济、文化等复杂活动且建立在自然系统基础之上的群体,是人类社会物质文明、精神文明最集中活跃的地方。城市空间结构已成为多学科领域研究的重点内容之一。本文对国内外城市空间结构研究进展进行了总结,并对下一步发展趋势进行了分析。     

Automated metric characterization of urban structure using building decomposition from very high resolution imagery

Classification approaches for urban areas are mostly of qualitative and semantic nature. They produce interpreted classes similar to those from land cover and land use classifications. As a complement to those classes, quantitative measures directly derived from the image could lead to a metric characterization of the urban area. While these metrics lack of qualitative interpretation they are able to provide objective measure of the urban structures.Such quantitative measures are especially important in rapidly growing cities since, beside of the growth in area, they can provide structural information for specific areas and detect changes. Rustenburg, which serves as test area for the present study, is amongst the fastest growing cities in South Africa. It reveals a heterogeneous face of housing and building structures reflecting social and/or economic differences often linked to the spatial distribution of industrial and local mining sites. Up to date coverage with aerial photographs is provided by aerial surveys in regular intervals. Also recent satellite systems provide imagery with suitable resolution. Using such set of very high resolution images a fully automated algorithm has been developed which outputs metric classes by systematically combining important measures of building structure. The measurements are gained by decomposition of buildings directly from the imagery and by using methods from mathematical morphology. The decomposed building objects serve as basis for the computation of grid statistics. Finally a systematic combination of the single features leads to combined metrical classes.For the dominant urban structures verification results indicate an overall accuracy of at least 80% on the single feature level and 70% for the combined classes.     

基于InSAR的城市地下轨道交通沉降与灾害监测

城市地铁建设会对邻域造成地质环境损伤,甚至发生灾变。传统基于点位测量的方法在实际应用过程中存在野外作业周期长、受天气影响及耗费大量人力物力等缺点。因此,本文基于城市地下轨道交通安全施工中的应用需求,以天津市地铁五号线为例,利用27景TerraSAR数据和PS-InSAR时序监测方法,对地下轨道交通地铁站和隧道施工影响进行了监测和评估。结果表明,PS-InSAR能在施工期间监测到地铁线及周边的形变,有利于城市轨道交通全生命健康监测。     

Analysis of human spatial behavior in a GIS environment: Recent developments and future prospects

In recent years, comprehensive geographic data sets of metropolitan areas and individual-level, georeferenced data are becoming more available to social scientists. At the same time, tools for performing spatial analysis in a GIS environment have also become more available. These developments provide many new opportunities for the analysis and theoretical understanding of disaggregate human spatial behavior. This paper examines how these developments may enable the researcher to represent complex urban and cognitive environments more realistically, and to overcome the limitations of aggregate spatial data framework. It explores their implications for the theoretical and methodological development in geography and other social science disciplines.     

基于GIS的安庆市应急避难场所空间布局特征分析与优化

随着城市发展步伐的加快,火灾、爆炸、公共卫生事故、工程事故等人为灾害性事件频发,洪水、地震、台风等自然灾害也给城市居民的生命和财产安全造成了极大损失。由于城市规模和人口数量将越来越大,城市应急避难场所在城市规划中就显得更加重要。本文以安庆城区为例,根据城市人口分布状况以及城市总体的空间布局,分析应急避难场所的特征及其与城市的适应程度。采用GIS的空间查询、网络分析、最佳路径分析等功能,检验该市应急避难场所的合理性。针对城市规划中应急避难场所空间布局上不合理的问题,进行方案优化。研究结果将给安庆市应急避难场所的空间布局带来一定的借鉴作用。     

Monitoring land surface and cover in urban and peri-urban environments using digital aerial photography

This paper describes the development of a system for decimetre-scale monitoring of land-surface and land-cover in urban and peri-urban environments. We describe our methodology that comprises the application of highly automated processing and analysis methods to digital aerial photography. The approach described in this paper addresses a monitoring need by providing the ability to generate change information at a spatial resolution suitable for urban, peri-urban and coastal areas, where an increasing percentage of the worlds’ population dwells. These areas are dynamic, with many environmental issues associated with planning, service provision, resource management and allocation, as well as monitoring regulatory compliance. We present a system based on standardised data and methods, which is able to track and communicate changes in features of interest in a way that has not been previously possible. We describe the methodology and then demonstrate its feasibility by applying it to geographic areas of planning and policy relevant size (the order of tens of thousands of square kilometres). We demonstrate the approach by applying it to the problem of urban forest assessment.     

一种基于地理探测器的城镇扩展影响机理分析法

城市化是全球范围内普遍存在的重要现象,尤其发展中国家和地区正经历着快速城市化的过程。快速城市化导致了城市地区的大规模扩张,从而加重了土地资源的压力,带来了一系列的环境和社会问题。定量分析城镇扩展的空间驱动力能更好地辅助城市规划与管理。本文提出了一种量化城镇扩展的指数——城镇扩展密度,并通过地理探测器方法分析了1990—2000年北京市城镇扩展的时空特征及形成机理。研究表明:北京市城镇扩展沿交通干线呈线性扩张,其城镇扩展受到社会经济和地理的共同影响和制约作用,城镇固定资产投资对城镇扩展影响力最大,区域条件次之。这些发现可以为城镇扩展模拟和预测提供更好的改进空间。     

Geometric methods for estimating representative sidewalk widths applied to Vienna’s streetscape surfaces database

Space, and in particular public space for movement and leisure, is a valuable and scarce resource, especially in today’s growing urban centres. The distribution and absolute amount of urban space—especially the provision of sufficient pedestrian areas, such as sidewalks—is considered crucial for shaping living and mobility options as well as transport choices. Ubiquitous urban data collection and today’s IT capabilities offer new possibilities for providing a relation-preserving overview and for keeping track of infrastructure changes. This paper presents three novel methods for estimating representative sidewalk widths and applies them to the official Viennese streetscape surface database. The first two methods use individual pedestrian area polygons and their geometrical representations of minimum circumscribing and maximum inscribing circles to derive a representative width of these individual surfaces. The third method utilizes aggregated pedestrian areas within the buffered street axis and results in a representative width for the corresponding road axis segment. Results are displayed as city-wide means in a 500 by 500 m grid and spatial autocorrelation based on Moran’s I is studied. We also compare the results between methods as well as to previous research, existing databases and guideline requirements on sidewalk widths. Finally, we discuss possible applications of these methods for monitoring and regression analysis and suggest future methodological improvements for increased accuracy.     

多源信息多尺度视角的南京市街道级人口模拟研究

人口是重要的社会和生态环境因素,掌握人口信息有利于资源配置和环境管理。本文以南京市的街道级行政区域作为基本对象单元,分别从市级、市郊级和城市化度3个尺度,人口总量和人口密度2个方面,使用NPP/VⅡRS夜间灯光数据、大数据中的关注点POI数据、Landsat 8卫星OLI影像的建筑用地指数IBI,进行了人口模拟研究。结果如下：①在市级层面,人口密度模拟效果优于人口总量的,POI数据模拟效果最佳,确定性系数为0.87,其次是建筑用地指数0.81,夜间灯光数0.77;②在市郊级层面,郊区的人口密度拟合效果优于市区的;③在城市化度方面,中度城市化的街道人口密度与NPP/VⅡRS的幂函数关系最佳,确定性系数为0.99,低度和高度城市化的街道人口密度与POI的对数关系拟合效果相对好些,确定性系数分别为0.65和0.44;中度和低度城市化街道的人口总量与3个因素数据的多元线性回归模型效果最佳,确定性系数分别为0.91和0.78。结果说明中度城市化街道的人口模拟效果最好。本文研究拓展了城市人口估算的广度和深度,可为相关工作提供思路上的借鉴。