Incorporating sprawl and adjacency measures in land‐use forecasting model: A case study of Collin County,TX

Sprawl measures have largely been neglected in land‐use forecasting models. The current approach for land‐use allocation using optimization mostly utilizes objective functions and constraints that are non‐spatial in nature. Application of spatial constraints could take care of the contiguity and compactness of land uses and can be utilized to address urban sprawl. Because a land‐use model is used as an input to transportation modeling, a better spatial allocation strategy for more compact land‐use projections will promote better transportation planning and sustainable development. This study formulates a scenario‐based approach to normative modeling of urban sprawl. In doing so, it seeks to improve the land‐use projections by employing a spatial optimization model with contiguity and compactness consideration. This study incorporates urban sprawl measures based on smart growth principles together with a mixed‐use factor, and adjacency consideration of nearby land uses. The objective function used in the study maximizes net suitability based on imposed constraints. These constraints are based on smart growth principles that enhance walkability in neighborhoods, promote better health for residents, and encourage mixed‐use development. The formulated model has been applied to Collin County, TX, a fast‐developing suburban county located to the north of the Dallas–Fort Worth metroplex. The suitability of land cells indicates the probability of conversion, which is calculated using spatial discrete choice analysis with Moran eigenvector spatial filtering for vacant cells at a resolution of 150 × 150 m employing factors of the built environment, and socioeconomic and demographic characteristics. This study demonstrates how spatial proximity between land uses, which has been ignored to date, can be used to control sprawl, resulting in better mixing of different land uses based on constraints imposed in a spatial optimization problem.     

基于中心点距离的居民地面要素聚类

空间聚类是将空间实体根据某些相似的特性聚类成为一个集合,这个集合称为簇。本文研究了一种基于中心点距离的居民地面要素聚类算法:通过获取面状要素的数据,运用基于其几何中心的距离计算方法,判断面要素之间距离的可达性,并将距离小于阈值的面要素进行聚类,最终以凸包的形式将该集合绘制出来。本文的算法是在VS2010以及ArcGIS Engine开发环境下通过编程实现,并进行多组实验,实验结果表明,该应用程序可以实现居民地面要素的自动聚类。     

出租车轨迹数据的南京人群出行模式挖掘

针对现有出租车轨迹数据挖掘中时间序列邻近度量方法存在的问题,提出一种基于DBSCAN算法和改进的DTW距离的时间序列聚类算法提取具有相似性出行特征的时空模式,进而研究城市人群出行行为的时空差异。以南京市为例,结合电子地图对出行模式的空间分布特征进行分析,证明了本文所提出的方法的有效性。实验结果表明:在空间分布上,工作日出租车出行模式按照平均出行频次由高到低排序,从城市中心向四周扩散,呈中心环状分布,出行模式区域界限较为明显,同类出行模式分布区域对应相似的功能。提出了一种基于DBSCAN算法和改进的DTW距离的时间序列聚类算法提取具有相似性出行特征的时空模式,有效地分析城市人群出行行为的时空差异。     

Socioeconomic Factors and Urban Tree Cover Policies in a Subtropical Urban Forest

Cities are increasingly promoting policies that increase and conserve urban forests based largely on biophysical and land use-cover metrics. This study demonstrates how socioeconomic factors need to be considered in geospatial analyses when formulating urban greening policies. Using remote sensing, geographical information systems, spatial field and census data, and policy analyses, we analyzed the effectiveness of urban forest cover policies that included socioeconomic factors when quantifying urban forest cover. We found that urban forest cover was heterogeneous across the study area and non-white residents younger than 19 and greater than 45 years old living in rentals were more likely to reside in areas with less urban forest cover than any other age cohort. Our analyses also indicated that urban forest cover was temporally variable and demographic factors unique to Miami-Dade County bring to light the complexity of establishing homogenous, county-wide "tree canopy" and urban greening policy goals. We present a localized socioeconomic and ecologically based geospatial approach for formulating urban forest cover goals.     

移动测量技术在城市绿化普查中的应用

在新时代的城市建设中,绿化建设对于美化城市面貌和提高市民居住舒适度显得十分重要,那么城市绿化普查工作则成为绿化建设工作中的重要一环。为了改进传统绿化普查工作,本文提供一整套基于移动测量技术的城市绿化普查方案,搭配自主研发的GIS采集软件和实景三维管理平台,采集绿化信息的效率和精度显著提高,更可以优化城市绿化管理方法。     

Revisiting the death of geography in the era of Big Data: the friction of distance in cyberspace and real space

Many scholars have argued that the importance of geographic proximity in human interactions has been diminished by the use of the Internet, while others disagree with this argument. Studies have noted the distance decay effect in both cyberspace and real space, showing that interactions occur with an inverse relationship between the number of interactions and the distance between the locations of the interactors. However, these studies rarely provide strong evidence to show the influence of distance on interactions in cyberspace, nor do they quantify the differences in the amount of friction of distance between cyberspace and real space. To fill this gap, this study used massive amounts of social media data (Twitter) to compare the influence of distance decay on human interactions between cyberspace and real space in a quantitative manner. To estimate the distance decay effect in both cyberspace and real space, the distance decay function of interactions in each space was modeled. Estimating the distance decay in cyberspace in this study can help predict the degree of information flow across space through social media. Measuring how far ideas can be diffused through social media is useful for users of location-based services, policy advocates, public health officials, and political campaigners.     

顾及地价空间分布规律的城市基准地价以价定级方法研究

提出了一种城市基准地价以价定级方法。该方法用矢栅混合模型划分评价单元,对地价样点进行趋势面分析筛选,使用最短路径距离代替欧氏距离对地价样点进行空间插值,叠加分析后得到各评估单元的指标地价,用其代替传统的因素综合得分对基准地价评估区域分等定级,同时测算出各级别基准地价。以上海市为例对该方法的实用性进行了验证。     

Routing of Road Network through Least Cost Pathway Algorithm to Minimize Impacts on Environment

In line with growth and sustainable development of the country and fundamental evolution of economic and social matters, the role of road networks becomes ever more significant. The network provides access to hot spots and movement of materials which are necessary for such a development. To address sustainable road development, GIS techniques were used to determine the optimum routes. All important parameters like slope, geology, landslide, etc. were selected, collated in a data base and used to create a cost layer. Then, using the Least Cost Pathway Algorithm, the four routes based on different cost layers were designed in GIS. These cost layers were calculated based on variable threshold values related to each criterion. Finally the optimum way was selected according to distance from landslide zone, fault lines, high slope areas and proximity to economical centres. As conclusion and in comparison, we found that currently designed road without regard to environmental factors may lead to selection of ways that will pass through inhibited zones increasing the likelihood of damage to the environment and economical costs.     

USE OF TRANSFORMED CARTOGRAPHIC IMAGES IN URBAN CONSTRUCTION STUDIES

The authors describe how maps compiled according to non-spatial “metrics” or systems of scaling can be used in the support of urban planning and construction efforts. In particular, maps scaled according to travel time instead of ordinary distance reveal inadequacies not only in urban mass transit, but permit assessment of the rationality of urban land use as a whole, by demonstrating the degree of effort that urban residents must expend to perform such basic activities as shopping, the journey to work, and access to essential services. A methodology for the compilation of such maps is described. Translated from: Izvestiya AN SSSR, seriya geograficheskaya, 1987, No. 1, pp. 100-105.     

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。     

Using Neural Nets to Model the Spatial Distribution of Seasonal Homes

Seasonal and second homes are important aspects of recreational tourism. Owning a summer cottage, time-share condominium, hunting cabin, or a part-time residence in a location away from home affects development patterns in significant ways. This paper presents the results of using an artificial neural network and a geographic information systems-based approach to identify and quantify the principal predictors of seasonal home distribution within the Lake States region of Minnesota, Wisconsin, and Michigan. Representative variables, such as proximity and spatial configuration of lakes, proximity to the Great Lakes shore, surrounding forest acreage, and public land access have been quantified using geographic information systems at the minor civil division (MCD) scale for the three states. The GIS data have then been fed into artificial neural networks to enable these pattern recognition tools to identify the principal predictors of seasonal home distribution in the Upper Great Lakes States.     

基于RS、GIS的杜蒙县土地利用结构变化研究

依据杜蒙县1990和2007年TM影像、土地利用变更统计数据,在土地利用结构数量、动态度指数及土地利用结构信息墒上,分析了该地区土地利用结构的变化.结果显示:杜蒙县土地利用类型分布较均匀,各类用地结构结构有一定差异.最后根据结果分析了杜蒙县土地利用结构变化的原因,并提出了土地利用的建议.     

基于复杂网络的国际农产品贸易分析

本文基于2001~2016年国际农产品贸易数据,采用复杂网络分析方法,评估各国在贸易网络中的地位,并借助QAP相关分析(Quadratic Assignment Procedure)探究国际农产品贸易网络结构的影响因素。研究结果表明:2001~2016年综合中心性排名前10的国家整体格局未发生剧烈变化,且大多为发达国家,美国、中国、德国位居前列;国家间的GDP、人口、国土面积、农业用地面积和外商直接投资的差异与全球农产品贸易显著正相关,而距离、收入差距对其有负向影响。     

Modeling relationships between the network distance and travel time dynamics for assessing equity of accessibility to urban parks

Static models of accessibility are usually based on the fixed distance or Average Travel Time (ATT) models. Because of ignoring the traffic as a dynamic process affecting the accessibility through the change of Travel Time (TT), these models lead to unperceived temporal inequities. In contrast to the consideration of the temporal Variation of TT (VTT) in the previous studies, the variation of traffic- related TT and its relations with network distance has not been considered. In this study, relations between VTT and network distance to access urban parks in Tehran megacity has been modeled. Traffic maps at five times of day are used to produce TT maps of Traffic Analysis Zones (TAZs) to their 3-closest parks. Comparison of the Gini coefficients of accessibility show significant inequities of accessibility at different times of day. Relations between the distance, ATT, and TTmax are modeled by statistical analysis. Results show both TT and TTmax have significant positive relations with distance and traffic and reach their maximum at 6 p.m. Observation of significant relations between distance, ATT, TTmax, and VTT provides interesting knowledge for the conversion of temporal measures of equity (TT) to a physical measure of equity (distance). A simple application of these findings for effective management of the spatiotemporal inequities is the definition of critical distances from public services. As an example, to decrease the TTmax of TAZs to less than 12 min, their maximum distance to the closest parks should be less than 4 km. The developed approach can be adopted for the accessibility evaluation of the other public services, particularly the health and education centers.     

显著空间同位模式的多尺度挖掘方法

空间同位模式挖掘对于揭示地理现象间的共生、依赖规律具有重要价值。然而,空间同位模式挖掘中参数阈值缺乏先验知识,若设置不合理,挖掘结果中会遗漏重要的模式或包含冗余的、甚至错误的模式。为此,本文提出了一种基于模式重建的显著空间同位模式多尺度挖掘方法。首先,定义了互邻近距离指标,该指标可用来确定距离阈值的有效取值范围。进而,以模式重建为基础构建零模型,借助统计检验的方法来发现显著的空间同位模式,从而避免了兴趣度阈值的设置。最后,对空间同位模式进行多尺度挖掘,并引入生存期的概念对同位模式多尺度挖掘结果进行有效性评价。试验结果表明:本文方法可有效降低算法参数设置的主观性,从而提升空间同位模式挖掘结果的准确性和稳健性。     

基于NDVI背景场的雪盖制图算法探索

NDSI算法提取MSS雪盖面积时,受到MSS影像缺少短波红外波段的局限。为充分精确提取MSS影像的雪盖面积,本文探索一种以NDVI为背景场的雪盖制图新思路。该方法首先在辐射校正时利用6S模型反演地表反射率,然后根据各地物的光谱特性差异和NDVI特性差异,在ENVI软件SPECTRAL模块中创建冰雪光谱阈值查找表。通过ETM＋和TM影像的三个例证,详细阐明该算法流程以及查找表的创建,并以NDSI对其雪盖制图进行精度验证。结果一致表明,与常规的分类方法（最大似然法）相比较,本文探索的NDVI背景场算法有更高的总体精度和Kappa系数。     

GIS软件在油气长输管道项目矿（产）权确认中的应用

通过在西气东输三线西段（二标段）管道工程项目运用,很好的解决了对矿（产）区、集体用地的矿（产）权确认,为管道经过矿（产）权区确定合理的补偿金额提供科学谈判依据;有效减少了补偿损失;为今后在长输管道穿越矿（产）区、集体用地的补偿提供了测算手段和方法,形成的补偿协议对管道运营单位确定管道权益和维护使用也具有现实意义。     

顾及功能语义特征的建筑物空间分布模式识别方法

本文从空间-语义双重约束角度,提出一种顾及空间邻近和功能语义相似的建筑物空间分布模式识别方法。首先,基于建筑物的空间位置邻近性(即建筑物间的最小距离)约束进行聚类,获得建筑物的空间分布模式和建筑物间的空间邻近关系;然后,根据建筑物的功能语义相似性约束进行分割,获得建筑物的初步聚类结果;最后,考虑簇内相似性与簇间差异性进行整体优化,获得最终聚类结果。试验验证表明,本文方法比现有方法能够更有效地识别空间邻近与功能语义一致的建筑物群,服务于智慧城市建设中对建筑物进行语义层次综合和对城市结构进行深入研究的需求。     

Jason-2卫星阈值重跟踪算法比较

选取Jason-2卫星在中国南海北纬15°~18.5°范围1 276个波形数据,依据Threshold算法和SeaIce算法对波形进行重跟踪,得到不同阈值水平下的距离改正结果。结果表明:当星下点轨迹靠近陆地时,距离改正值增大。然后,依据不同方法、不同阈值水平对应的距离改正值对卫星观测的海面高实施修正,得到相应的海面高结果。作为验证,选取法国国家太空研究中心(CNES)发布的海面高作为外部检核条件。将修正后的海面高与CNES公布的海面高进行较差比较,较差值的统计分析表明:SeaIce重跟踪算法在阈值水平为50%时,差值的标准差明显小于其他方法的计算结果。     

Quantifying determinants of cash crop expansion and their relative effects using logistic regression modeling and variance partitioning

Cash crop expansion has been a major land use change in tropical and subtropical regions worldwide. Quantifying the determinants of cash crop expansion should provide deeper spatial insights into the dynamics and ecological consequences of cash crop expansion. This paper investigated the process of cash crop expansion in Hangzhou region (China) from 1985 to 2009 using remotely sensed data. The corresponding determinants (neighborhood, physical, and proximity) and their relative effects during three periods (1985–1994, 1994–2003, and 2003–2009) were quantified by logistic regression modeling and variance partitioning. Results showed that the total area of cash crops increased from 58,874.1 ha in 1985 to 90,375.1 ha in 2009, with a net growth of 53.5%. Cash crops were more likely to grow in loam soils. Steep areas with higher elevation would experience less likelihood of cash crop expansion. A consistently higher probability of cash crop expansion was found on places with abundant farmland and forest cover in the three periods. Besides, distance to river and lake, distance to county center, and distance to provincial road were decisive determinants for farmers’ choice of cash crop plantation. Different categories of determinants and their combinations exerted different influences on cash crop expansion. The joint effects of neighborhood and proximity determinants were the strongest, and the unique effect of physical determinants decreased with time. Our study contributed to understanding of the proximate drivers of cash crop expansion in subtropical regions.