Urban flood risk assessment under rapid urbanization in Zhengzhou City,China

With accelerated urbanization and climate change,urban flooding is becoming more and more serious.Flood risk assessment is an important task for flood management,so it is crucial to map the spatial and temporal distribution of flood risk.This paper proposed an urban flood risk assessment method that takes into account the influences of hazard,vulnerability,and exposure,by constructing a multi-index urban flood risk assessment framework based on Geographic Information System(GIS).To determine the weight values of urban flood risk index factors,we used the analytic hierarchy process(AHP).Also,we plotted the temporal and spatial distribution maps of flood risk in Zhengzhou City in 2000,2005,2010,2015,and 2020.The analysis results showed that,the proportion of very high and high flood risk zone in Zhengzhou City was 1.362%,5.270%,4.936%,12.151%,and 24.236%in 2000,2005,2010,2015,and 2020,respectively.It is observed that the area of high flood risk zones in Zhengzhou City showed a trend of increasing and expanding,of which Dengfeng City,Xinzheng City,Xinmi City,and Zhongmu County had the fastest growth rate and the most obvious increase.The flood risk of Zhengzhou City has been expanding with the development of urbanization.The method is adapted to Zhengzhou City and will have good adaptability in other research areas,and its risk assessment results can provide a scientific reference for urban flood management personnel.In the future,the accuracy of flood risk assessment can be further improved by promoting the accuracy of basic data and reasonably determining the weight values of index factors.The risk zoning map can better reflect the risk distribution and provide a scientific basis for early warning of flood prevention and drainage.

A spatiotemporal intelligent framework and experimental platform for urban digital twins

Backgrounds This work emphasizes the current research status of the urban Digital Twins to establish an intelligent spatiotemporal framework.A Geospatial Artificial Intelligent(GeoAI)system is developed based on the Geographic Information System and Artificial Intelligence.It integrates multi-video technology and Virtual City in urban Digital Twins.Methods Besides,an improved small object detection model is proposed:YOLOv5-Pyramid,and Siamese network video tracking models,namely MPSiam and FSSiamese,are established.Finally,an experimental platform is built to verify the georeferencing correction scheme of video images.Result The MultiplyAccumulate value of MPSiam is 0.5B,and that of ResNet50-Siam is 4.5B.Besides,the model is compressed by 4.8times.The inference speed has increased by 3.3 times,reaching 83 Frames Per Second.3%of the Average Expectation Overlap is lost.Therefore,the urban Digital Twins-oriented GeoAI framework established here has excellent performance for video georeferencing and target detection problems.

A GIS-based Spatial Analysis of Housing Price and Road Density in Proximity to Urban Lakes in Wuhan City, China

As one of the essential urban open spaces, lakes usually contribute immensely to the quality of residents′ daily lives. Different from hedonic approach employed in existing researches on urban open spaces in China, this paper integrates housing price surface with road density to analyze the spatial characteristics in proximity to urban lakes in Wuhan City, China. With the expansion of Wuhan City, urban lakes became polluted, they shrunk or even disappeared, leading to unfavorable conditions for sustainable development of the city. To better understand the spatial relationship between the city and lakes, we classify the urban lakes in Wuhan central area into ′lakes in the urban center′ and ′lakes in urban fringe′. Based on housing price surface we explore the spatial characteristics in proximity to different lakes and differences between the lakes. We also use Geographic Information System(GIS) tool to calculate road density as a supplementary indicator to reflect the accessibility in proximity to urban lakes. The results indicate that relative independence exists between different towns, and the spatial characteristics are different depending on scales and locations. In most of cases, the road density is lower where closer to the lakeshore while the housing price exhibits an opposite pattern. We conclude that city governments and urban planners should give more considerations to these spatial differences, somewhere should be better planned and protected as an important waterfront and somewhere the control of unreasonable real estate development nearby should be strengthened.

URBAN INVESTMENT ENVIRONMENT INFORMATION SYTEM FOR CHINA′S COASTAL PORT CITIES

The Paper mainly applies multi-disciplinary theory, methods and geographic information system (GIS) technology to study the investment environment for coastal port cities. The methods of studying urban investment environment using GIS prompted. In this peper, it is mentioned that the study of investment environment with GIS can be divided into 3 layers of macro scope, medium scope and micro scope in the paper. A powerful user-friendly UIEIS (Urban Investment Environment Information System) has been designed to study the urban investment environment. A series of application analysis models (including investment environment assessment models,investment site selection models, documental data management models, statistical data.graph display model, economic analysis and prediction models, network analysis models) are developed for investment environment studies in coastal port cities. Ningbo, a very important coastal port city, is chosen as a pilot study city.

基于多源信息融合的城市规划决策信息系统

多源信息融合通过将多源异构的数据进行集成处理和关联分析,从而实现多源信息的互补集成和综合利用。地理信息系统可实现矢量、栅格、三维模型、实时传感数据等多源异构信息服务的集成与融合,在此数据融合的基础之上进行功能开发,可进一步实现面向城市规划领域的决策级信息融合平台。文章结合章丘区多规合一及三维数字城市决策系统建设的具体实践,详细阐述了多源数据获取、处理、集成、关联融合及系统定制开发的实施过程,通过多源信息融合推动了章丘区城市规划手段升级,提高了规划决策水平。

地理信息系统在现代城市测绘中的应用分析

优化城市空间布局,全面提升城市品质和综合服务功能,以新的发展理念推动城市跨越式的发展,建设美好城市,科学规划要先行。然而,城市测绘是科学规划的重要基础,随着新型基础测绘体系及地理信息公共服务体系逐渐地完善,城市数字化建设正快速转向智慧化建设。在现代城市测绘中地理信息系统已成为城市测绘主要应用技术,利用地理信息系统的多种技术优势可为城市建设管理提供更可靠的数据和技术服务。该文从地理信息系统的技术优势出发,旨在进一步分析城市测绘中如何发挥地理信息系统技术应用的更大优势,加快提升城市测绘技术水平,更加科学统筹规划城市建设,着力构建城市新的发展格局。

基于地理信息系统的城市数字化地图的研究与设计

文章深入研究了基于地理信息系统(GIS)的城市数字化地图的设计与应用,首先探讨了数字化地图的数据采集方法,重点分析了遥感技术、实地调查和第三方数据源的应用和优势。随后,文中详细描述了数据预处理、格式化和标准化的流程,确保数据的准确性和可靠性。在此基础上进一步讨论了数字化地图在城市规划、交通管理、环境监测以及公共服务与应急管理等关键领域的具体应用,强调了GIS在现代城市发展中的核心作用,并为其未来的研究和应用提供了有益的启示和建议。

CIM在雄安新区建设管理中的创新应用

从国家、地方的相关政策文献,分析数字孪生城市对CIM技术发展的推动,介绍了雄安新区在住房和城乡建设部关于城市信息模型(CIM)试点的进展及成果;然后从建设管理需求、创新应用场景、碰撞检测算法等方面阐述数字建设协同管理平台的应用,并以雄安新区雄东片区A单元的工程项目建设为试点,开展数字化建设协同管理平台在工程建设上的示范应用,在实践中形成了线上线下一体化管理、碰撞分析、模地一致性检验的创新应用场景。最后总结了雄安CIM数字化建设协同管理平台的应用成效,有效减少施工返工成本,保障工程建设周期,助力新区高质量建设、高水平管理和高质量疏解发展,促进数字孪生城市的建设与发展。

信息生态链视角下城市治理模式解析研究

城市信息模型、城市体检、城市更新是当前城市治理的创新手段,本文以信息生态链的视角来分析三者的逻辑关系,构建以三者为主体的城市治理信息生态链,通过信息生态链运转实现信息增值,赋能城市建设。从信息流转、信息协同、信息增值三个方面来分析影响生态链运转的因素,提出信息生态链建设框架,探讨平台、数据治理、数字可视化等关键研究内容。

面向新型基础测绘的测绘地理信息档案数字化实践

在新型基础测绘和实景三维中国建设中,测绘地理信息档案不可或缺,测绘地理信息档案数字化是测绘档案信息的源头,已经超过了简单的档案整理和信息保存,成为新型基础测绘建设的重要一环。结合国家加快推进新型基础测绘体系建设的需求,提出了对新时期测绘地理信息档案数字化的新认识,给出了新思路,并进行了实践。建设方案有助于提高测绘地理信息档案的服务能力。

新时期数字城市和城市信息化建设中存在的问题及路径探索

随着信息技术和互联网技术的不断发展和普及,推动城市的数字化转型,进一步把万物互联、信息数据传输,整合、分析应用到城市建设、运行、管理的方方面面,已经成为改善城市治理体系,提升智能化城市管理水平必由之路和大势所趋。通过开展数字城市和城市信息化建设,有利于在交通运输、市政建设、政务服务、应急保障、便民服务、营商环境以及民生改善方面借助数字化的优势,推动城市基础能力和延伸保障水平得到飞跃式发展,但我国数字城市和城市信息化建设较晚,目前存在信息资源整合利用能力不足、建设规范和标准水平不高、创新意识和创新能力不强等问题。本文通过论述数字城市构建和城市信息化建设目标以及评价指标,结合建设现状,深入分析存在的问题,探讨推进数字城市建设的优化路径,更好地助推新型数字城市的打造,提升城市信息化建设的品质水平。

基于Urban DEM的3D GIS可视化分析

针对如何快速和精确地构建Urban DEM,以及如何基于Urban DEM进行3D可视化分析,利用南京旧城区1 500地形图和建筑规划图构建5 m分辨率的Urban DEM,在此基础上探讨3D可视化分析方法。实验结果证明,基于Urban DEM进行3D可视化分析具有可行性。

Two-and Three-Dimensional Urban Core Determinants of the Urban Heat Island： A Statistical Approach

There is no doubt that the UHI （urban heat island） is a mounting problem in built-up environments, due to the energy retention by surface dense building materials, leading to increased temperatures, air pollution, and energy consumption. Much of the earlier research on the UHI has used two-dimensional （2-D） information, such as land uses and the distribution of vegetation. In the case of homogeneous land uses, it is possible to predict surface temperatures with reasonable accuracy with 2-D information. However, three-dimensional （3-D） information is necessary to analyze more complex sites, including dense building clusters. In this research, 3-D building geometry information is combined with 2-D urban surface information to examine the relationship between urban characteristics and temperature. The research includes the following stages： （1） estimating urban temperature; （2） developing a 3-D city model; （3） generating geometric parameters; and （4） conducting statistical analyses using both linear and non-linear regression models. The implications of the results are discussed, providing guidelines for policies aiming to reduce the UHI.

基于CityEngine CGA规则的三维数字城市建模

针对当前数字三维城市建模工作量庞大、周期较长的问题,本文基于CityEngine提出了一种CGA规则建模方法,该法利用既有二维数据,通过建立规则,实现区域建筑物和构筑物批量建模。实验结果表明,CGA规则化建模可动态构建三维建筑模型,模型的编辑性较强。相似建筑物可重复使用同一规则,因此大大提高建模速度。同时,CGA规则化建模可减小数据获取成本,缩短建模周期,大幅提高建模效率。

Understanding the Urban Sprawl in the Mid-Size Latin American Cities through the Urban Form:Analysis of the Concepcion Metropolitan Area(Chile)

Latin American cities, like those from North America and Europe, experience problems of urban sprawl. However, few studies have dedicated exclusively to this phenomenon in specific cities, and this omission is particularly noticeable regarding cities not considered among the megalopolis of the continent. The present work analyzes urban sprawl through an urban form in the Concepción Metropolitan Area, Chile, between 1990 and 2009, considering local aspects that may have played a role in the process. The main empirical results obtained from this study reveal a metropolitan area that has expanded intensely over a 20-year period, growing from 9000 hectares to more than 17,000 ha for a 96% increment in the built-up area. The new urban surfaces consolidate a central conurbation that strengthens the role of the main downtowns, with less-intense occupation towards the sub-centers but in a structure that follows the transportation infrastructure. Over the last 20 years, the distance between the shapes has grown progressively by around 2 km, increasing the size of the ellipse by more than 1000 km2. In particular the complexity of the urbanized surfaces has grown, becoming more irregular in shape and less compact as they come to occupy larger areas. So our principal findings include: an increment of nearly 100% in the urban surface, the importance of a polycentric urban structure in the process of consolidation as a support for analyzing different spatial dynamics, and the growing morphological irregularity of the territory of the sprawl.

Procedural modeling applied to the 3D city model of Bogota:A case study

Background Computer Generated Animations(CGA),when applied to three-dimensional(3D)city models(3DCM),can be used as powerful tools to support urban decision-making.This leads to a new paradigm,based on procedural modeling,that allows the integration of known urban structures.Methods This paper introduces a new workflow for the development of high-quality approximations of urban models in a short time and enables facilities to be imported from other cities into a given city model,following specific generation rules.Results Thus,this workflow provides a very simple approach to observe,study,and simulate the implementation of models already developed in other cities,in a city where they are not yet adopted.Examples of these models include all types of mobility systems and urban infrastructure.Conclusions This allows us to perceive the environmental impact of certain decisions in the real world,as well as to carry out simple simulations to determine the changes that can occur in the flows of people,traffic,and other city activities.

基于路网中心性的近代南京城市寺庙选址特征

寺庙是重要的公共空间,探究选址特征可挖掘其在城市中的地位与功能变化,是社会变迁与城市发展的缩影。基于ArcGIS和GeoDa平台,研究近代南京城市寺庙选址与路网中心性的耦合特征,探讨城寺关系,结果如下。1)寺庙选址。清末,寺庙多集中于城南和城西,寺庵、祠庙均由城南向城北扩散;民国,寺庵在城北呈多点集聚,祠庙则向中华门外扩展。2)城寺互动。近代城市寺庙与路网之间的相关性逐渐降低,在城市中的区位逐渐边缘化。清末,寺庙毗邻城市中心,与商业空间互融,城寺互动紧密;民国,寺庵与路网相关性远大于祠庙,在城市中占据更加优良的区位,祠庙因政权的转型、城市建设的影响而走向衰落。系统构建了近代南京城市寺庙GIS数据库,可为城市史、风景园林历史与理论研究提供量化方法参考,对南京近代寺庙遗产活化及当代寺观园林的选址具有实践意义。

平台城市主义视角下数字化日常出行的社会文化地理分析:广州案例

2000—2020年,随着平台经济和智慧城市的快速发展,人文地理学开始关注数字技术如何在平台应用的情境下进行地理知识的生产。在此背景下,本研究基于平台城市主义的视角,以广州为案例地,探讨了出行者借助数字平台开展日常出行活动的社会文化特征及其塑造的“人−平台−空间”关系。研究发现,广州城市居民的日常出行活动已与数字平台高度融合。但对于不同的群体而言,其使用平台制定出行计划、进行出行活动的具体方式都存在一定的差异。此外,出行活动发生的具体情境也增强了数字化日常出行的复杂性,塑造了计划性出行、偶然性出行、灵活性出行等多种出行模式,并促使它们以不同的形式在现实实践中相互交织。归根结底,上述多样化的数字化日常出行是出行者、数字平台与城市空间共同作用的结果,以“指南”和“磨合”为代表的互动方式分别体现了平台对出行过程的影响以及个体主观能动性的作用。本研究丰富了数字化出行相关研究的分析视角,有助于为未来数字中国与智慧城市的建设提供更具人本主义的观点。

开封市城区公园对城市热岛效应的缓解效果研究

城市热岛效应是影响城市生态系统的重要因素,也是影响城市生态文明建设的重要因素。公园作为城市内生态系统的重要组成部分,具有较高的生态服务功能,其布局和质量反映了一个城市的生活质量,同时也对促进城市可持续发展、保障城市安全起着无可替代的作用。利用遥感影像反演技术获取地表温度,通过对比不同时期、不同地表地物构成所导致的地表温度分布情况,探讨了城区公园对开封市城区热岛效应的缓解效果。

基于数字城市地理空间框架的市县一体化地理信息公共服务平台建设——以湖南省郴州市为例

数字城市地理空间框架是通过采集、加工、分发、服务基础地理信息资源,以公共服务为导向的国家空间信息基础设施。该文以数字郴州市县一体化平台建设为例,通过市县一体化地理信息资源、市县一体化地理信息公共服务平台、市县一体化支撑环境、市县一体化标准规范、市县一体化应用示范5个方面进行分析,讨论数字城市市县一体化的可行性。