Relationship Between Urban Road Traffic Characteristics and Road Grade Based on a Time Series Clustering Model： A Case Study in Nanjing, China

With the increasing number of vehicles in large-and medium-sized cities challenges in urban traffic management, control, and road planning are being faced. Taxi GPS trajectory data is a novel data source that can be used to study the potential dynamic traffic characteristics of urban roads, and thus identify locations that show a notable lack of road planning. Considering that road traffic characteristics on their own are insufficient for a comprehensive understanding of urban traffic, we develop a road traffic characteristic time series clustering model to analyze the relationship between urban road traffic characteristics and road grade based on existing taxi trajectory data. We select the main urban area of Nanjing as our study area and use the taxi trajectory data of a single month for evaluating our method. The experiments show that the clustering model exhibit good performance and can be successfully used for road traffic characteristic classification. Moreover, we analyze the correlation between traffic characteristics and road grade to identify road segments with planning designs that do not match the actual traffic demands.

Urban Economic Cluster Template and Its Dynamics of Beijing,China

Economic clusters have been a central focus of current urban and regional research, policies and practices. However, a methodology to identify and analyze policy-relevant economic cluster dynamics is still not well developed. Based on input-output(I-O) data of 1987, 1992, 1997, 2002 and 2007 of Beijing, this article presents an adapted principle component analysis for identifying the evolution of local economic cluster patterns. This research addresses the changes of economic interaction of industries with complementary and common activities over time. The identified clusters provide an insight into the reality of economic development in a diversifying urban economy: the increasing importance of services and the growing interaction between service and manufacturing industries. Our method therefore provides the analysts with a better understanding of the emergence, disappearance and development of economic clusters citywide. The results could be used to assist monitoring urban economic development and designing more practical urban economic strategies.

Spatial pattern and drivers of urbanization in China's mid-level developing urban agglomeration:A case study of Chang-Zhu-Tan

Urban agglomeration has become the main form of regional spatial organization in China.While most of the existing studies of urban agglomeration in China have focused on the eastern coastal areas,urban agglomeration with mid-level development in the rest of the country has been overlooke1.To better understand the urbanization process of the mid-level developing urban agglomeration,this study investigated the clustering pattern and the drivers of both urban population and firm dynamics during 2005-2015 in the Changsha-Zhuzhou-Xiangtan(Chang-Zhu-Tan)urban agglomeration of China using the methods ofkernel density estimation and geographic detection.Our results show that centralization was obvious,although decentralization also occurred in Chang-Zhu-Tan,and that the spatial agglomeration was promoted by several factors,such as administrative resources,location advantage,labor cost,and consumption capacity.Some problems hindering the development of this region were also discovered:administrative resources played a critical role in urbanization because small towns and villages did not receive enough attention,and the effect of local policy was not as beneficial as expected.These findings partly explain the relatively slow development of mid-level developing urban agglomerations and have important implications for promoting healthier urbanization.

Cluster Development of Zhengzhou Urban Agriculture Based on Diamond Model

Based on basic theory of Diamond Model,this paper analyzes the competitive power of Zhengzhou urban agriculture from production factors,demand conditions,related and supporting industries,business strategies and structure,and horizontal competition.In line with these situations,it introduces that the cluster development is an effective approach to lifting competitive power of Zhengzhou urban agriculture.Finally,it presents following countermeasures and suggestions:optimize spatial distribution for cluster development of urban agriculture;cultivate leading enterprises and optimize organizational form of urban agriculture;energetically develop low-carbon agriculture to create favorable ecological environment for cluster development of urban agriculture.

Design Strategies of Urban Cluster Based on the Concept of Green Transportation

Taking the planning practice of green transportation in Sino-Singapore Tianjin Eco-city as an example,the key factors and design strategies for its healthy development were summarized from the aspects of the coordination of land use and traffic development,the development of the public transport plus slow traffic model,and the development of reasonable and humanized traffic management measures,through analyzing the connotation and scale of green cluster.In addition,the design strategies of the green transportation concept suitable for the development of urban clusters represented by Guangming New District in Shenzhen were proposed,so as to provide a reference for promoting better the coordinated development of green traffic and cities,and maximizing the economic,social and environmental benefits of green transportation development.

Method for Evaluating the Influence of Obstruction of Sea Breeze by Clusters of High-Rise Buildings on the Urban Heat Island Effect

This study aims to propose a method for quantitatively evaluating the influence which the obstruction of sea breezes by clusters of high-rise buildings has on the urban heat island effect using a weather simulation model and Geographic Information Systems (GIS). Specifically, a method of evaluating the influence of the obstruction of sea breeze by high-rise buildings on the urban heat island effect was proposed. In the method, two scenarios that imagine urban forms which differ with regard to whether or not they contain high-rise buildings are created and weather simulation is conducted, and the results of the simulations are comparatively analyzed focusing on temperature and wind speed. Evaluation was conducted in two stages, and Shiodome of Minato City in the Tokyo Metropolis was selected as the region for evaluation. In two stages of evaluation, a rise in temperature of approximately 0.3 K and a reduction in wind speed of approximately 1 m/s were observed in a region approximately five to ten kilometers square downwind of high-rise buildings in the period 6 PM to 9 PM, and a higher temperature caused by the obstruction of sea breeze by high-rise buildings was identified. The fact that such a higher temperature was confirmed in the time period from 6 PM onwards, in which the temperature decreases, reveals that obstruction of sea breeze by high-rise buildings dulls the decrease in temperature which occurs from evening onwards, and influences nighttime urban heat island formation.

Study on the Coexistence of Two Tourism Clusters in Shenyang City and Corresponding Suggestions

Shenyang is a tourist city in northeast China. There exist two industry clusters related to tourism in Shenyang. One cluster mainly provides services to foreign tourists, including tourists from other countries and those from other parts of China. The other cluster mainly meets the demand of local residents for recreation and relaxation. In the essence of travel experience, foreign tourists prefer to get to know the world of local people, gain insights into their living conditions and lifestyles, and gain more real experience and fun of the travel by consuming the same travelling and recreation services and facilities as the local residents. This essay explores causes of the incompatible co-existence of the two clusters mentioned above as well as suggestions to speed up the integration of the two clusters.

Spatial Pattern Evolution and Casual Analysis of County Level Economy in Changsha-Zhuzhou-Xiangtan Urban Agglomeration, China

In order to evaluate whether or not the county units′ economy in the Changsha-Zhuzhou-Xiangtan(Chang-Zhu-Tan) Urban Agglomeration was growing as expected, this study analyzed the spatial economy pattern at county-level by using the Exploratory Spatial Data Analysis(ESDA) method. In this process, the global Moran′s I and local Getis-Ord G*i indexes were employed to analyze indicators including per capita GDP and three industrials(i.e. primary, secondary and tertiary industry) from 2000 to 2010. The results show that: 1) the county units′ economy in the Chang-Zhu-Tan Urban Agglomeration has exhibited a strong spatial autocorrelation and an accelerated integration trend since 2008(Moran′ s I increased from 0.26 to 0.56); 2) there is a significant difference in economy development between the northern and southern county units in the Chang-Zhu-Tan Urban Agglomeration: the hotspot zone with high economic level was formed among the northern county units whereas the coldspot zone with low economic level was located in the southern areas. This difference was caused primarily by the increasingly prominent economic radiation effect of Changsha ′upheaval′; 3) town density, secondary industry, and the integration policy are the major contributors driving the evolution of the spatial economy pattern in the Chang-Zhu-Tan Urban Agglomeration.

What is the relationship between ecosystem services and urbanization? A case study of the mountainous areas in Southwest China

China is undergoing a rapid urbanization process,and urbanization will have a direct impact on regional ecosystems and affect regional ecosystem services.Considering the mountainous counties in Southwestern China as the research object,this study reveals the spatial clustering characteristics of four typical ecosystem services(food production,soil conservation,water yield and carbon sequestration)as well as the trade-offs and synergies among ecosystem services in different urbanized areas.At the same time,piecewise linear regression is used to determine the threshold of the influence of urbanization on ecosystem services.The results indicate that:1)There are spatial autocorrelations among the four typical ecosystem services;with strong clustering characteristics,the positive correlation types are"clustered"locally;and with significant spatial heterogeneity,the negative correlation types are scattered and mainly appear in the highly urbanized area.2)There are also remarkable differences in the relationship among various ecosystem services in different urbanized areas,and in particular,there are marked trade-offs between food production and carbon sequestration in the moderately urbanized area and the highly urbanized area.However,there are synergies between them in the lowly urbanized area.3)With an increase in the compounded night light index(CNLI),water yield,carbon sequestration,food production and overall ecosystem services values present an increasing-decreasing trend,the soil conservation function value shows a decreasing-increasing trend.The response of water yield,carbon sequestration,food production,and overall ecosystem services to the compounded night light index(CNLI)has a threshold of 1.2642,1.4833,1.3388,1.5146 and 1.2237,respectively.Based on the detected relationships between urbanization and ecosystem services,this study provides a theoretical reference for the selection of urbanization development models in key ecological functional areas.

Geochemical baseline determination and contamination of heavy metals in the urban topsoil of Fuxin City,China

Urban topsoil is the most frequent interface between human society and natural environment.The accumulation of heavy metals in the urban topsoil has a direct effect on residents'life and health.The geochemical baseline of heavy metals is an objective description of the general level of heavy metals in the urban topsoil.Meanwhile,the determination of geochemical baseline is necessary for regional environmental management,especially in coal cities prone to heavy metal pollution.Heavy metal pollution has become an environmental problem in Fuxin City,China for a long time.To establish the geochemical baseline of heavy metals in the topsoil of Fuxin City and to evaluate the ecological risk of the topsoil,we collected 75 topsoil samples(0–20 cm)and analyzed the concentrations of Cu,Ni,Zn,Pb,Cr,Cd,Hg and As through X-ray fluorescence spectrometry,atomic absorption spectrometry and inductively coupled plasma optical emission spectrometry.We determined the geochemical baseline of heavy metals in the topsoil of Fuxin City by using iteration removal,box-whisker plot,cumulative frequency curve and reference metal normalization;evaluated the contamination risk and ecological risk of the topsoil by using the baseline factor index,Nemerow index and Hakanson potential ecological risk index;and identified the source category of heavy metals in the topsoil by using a pedigree clustering heatmap.Results showed that the geochemical baseline values were 42.86,89.34,92.23,60.55,145.21,0.09,0.08 and 4.17 mg/kg for Cu,Ni,Zn,Pb,Cr,Cd,Hg and As,respectively.The results of Nemerow index and Hakanson potential ecological risk index indicated that the urban topsoil in the study area was slightly contaminated and suffering low potential ecological risk.The main contaminated areas dominated in the middle part and northeast part of the study area,especially in the western Haizhou Strip Mine.The result of baseline factor index indicated that Hg and Cd were the major pollution elements.Using a pedigree clustering heatmap,we divided the sources of these heavy metals into three types:type I for Ni and Cr,largely represented the enrichment of heavy metals from natural sources;type II for Cu,Pb,Zn,Cd and As,mainly represented the enrichment of heavy metals from anthropogenic sources;and type III for Hg,represented the form of both natural and anthropogenic inputs.

Evaluation of Urban Development Quality Based on the Connotation of High-Quality Development: A Case Study of Guangdong Province

In this paper, based on the interpretation of the connotation of high-quality development, an urban development quality evaluation index system was established from six aspects of economic strength, the level of science and education, government management, resources and environment, the level of openness, and infrastructure, the entropy method and cluster analysis were used to conduct an empirical analysis of the quality of urban development in Guangdong Province, and relevant suggestions were proposed accordingly. The results showed that:(1) the level of science and education was the most important factor affecting the quality of urban development in Guangdong Province;(2) the quality of urban development in Guangdong Province was extremely uncoordinated;(3) cities with stronger economic strength had lower resource and environment evaluation;(4) cities of Guangdong Province could be divided into three categories: cities in a quality optimization stage, cities in a quality improvement stage, and cities in a quality lagging stage that could be further divided into three categories.

Establishment and Application of Urbanization Strategic Environ-mental Assessment Integration Technology System

Urbanization strategic environmental assessment (SEA) is an effective instrument to enhance the harmo-nious development of urban complex system, integrating of environment and development in decision-making. Ur-banization strategic environmental assessment integration technology system (SEA-ITS) is composed of "3S" (RS, GIS and GPS), environmental expert system and environmental model system, coupling with appropriate SEA working process closely. In this paper, the structure and components of SEA-ITS are analyzed based on Chinese characteristics, meanwhile methods to fulfill the following system functions are discussed: urbanization SEA in-quiring, analysis, discrimination, assessment, prediction, decision-making and output. Moreover, methods and tech-nologies employed in different urbanization SEA hierarchies are summarized. As a case study, urbanization SEA-ITS is applied in Changchun City to solving complex real problems. Methods such as system dynamics and grey cluster are adopted to achieve the environmental impact assessment on the eco-industrial system planning. It is revealed that the system designed is capable of reflecting the dynamic behavior of eco-industrial system under different sce-narios, meanwhile accomplishing strategy optimization and supplying scientific reference. The 4th strategy, namely concerning on economy increase and its interaction with science, technology and environment progress, would have the best efficiency. Further, more attention should be paid to the secondary development of integration techniques and function modification system of urbanization SEA-ITS.

Empirical Analysis on the Rural Urbanization Development in Luoyang City,China

Development status of rural urbanization in Luoyang City is introduced.A total of 6 indices are selected,such as total households in townships,total population in townships,total grain output,financial budget income,balance of savings deposits at the end of the year,and per capita net income of farmers.According to the data in 2009 Luoyang Statistical Yearbook,cluster analysis of 53 designated towns is carried out.Result shows that 53 designated towns are divided into 4 types according to the economic strength.Problems in the development of rural urbanization in Luoyang City are analyzed,such as imperfect management system,lack of effective economic measures,irrational town layout,unbalanced regional development,inadequate urban infrastructure,limited population absorption,lack of main industry in small towns,insufficient development capital,serious environmental pollution,and great pressure on environmental protection of towns.Countermeasures for the development of rural urbanization in Luoyang City are put forward.For instance,judging from the dynamic mechanism,Luoyang City should gradually change its dynamic mechanism of urbanization into socialist market system.Judging from the scale of town,Luoyang City should actively develop the central city and cultivate strong counties and key towns.Judging from the function of town,Luoyang should select a special urban development mode with its own characteristics for its development of rural urbanization.

Analyzing the Urban Hierarchical Structure Based on Multiple Indicators of Economy and Industry: An Econometric Study in China

For a city,analyzing its advantages,disadvantages and the level of economic development in a country is important,especially for the cities in China developing at flying speed.The corresponding literatures for the cities in China have not considered the indicators of economy and industry in detail.In this paper,based on multiple indicators of economy and industry,the urban hierarchical structure of 285 cities above the prefecture level in China is investigated.The indicators from the economy,industry,infrastructure,medical care,population,education,culture,and employment levels are selected to establish a new indicator system for analyzing urban hierarchical structure.The factor analysis method is used to investigate the relationship between the variables of selected indicators and obtain the score of each common factor and comprehensive scores and rankings for 285 cities above the prefecture level in China.According to the comprehensive scores,285 cities above the prefecture level are clustered into 15 levels by using K-means clustering algorithm.Then,the hierarchical structure system of the cities above the prefecture level in China is obtained and corresponding policy implications are proposed.The results and implications can not only be applied to the urban planning and development in China but also offer a reference on other developing countries.The methodologies used in this paper can also be applied to study the urban hierarchical structure in other countries.

Estimating model for urban carrying capacity on bike-sharing

As the demand for bike-sharing has been increasing,the oversupply problem of bike-sharing has occurred,which leads to the waste of resources and disturbance of the urban environment.In order to regulate the supply volume of bike-sharing reasonably,an estimating model was proposed to quantify the urban carrying capacity(UCC)for bike-sharing through the demand data.In this way,the maximum supply volume of bike-sharing that a city can accommodate can be obtained.The UCC on bike-sharing is reflected in the road network carrying capacity(RNCC)and parking facilities’carrying capacity(PFCC).The space-time consumption method and density-based spatial clustering of application with noise(DBSCAN)algorithm were used to explore the RNCC and PFCC for bike-sharing.Combined with the users’demand,the urban load ratio on bike-sharing can be evaluated to judge whether the UCC can meet users’demand,so that the supply volume of bike-sharing and distribution of the related facilities can be adjusted accordingly.The application of the model was carried out by estimating the UCC and load ratio of each traffic analysis zone in Nanjing,China.Compared with the field survey data,the effect of the proposed algorithm was verified.

Towards Urban Resource Flow Estimates in Data Scarce Environments: The Case of African Cities

Data sourcing challenges in African nations have led many African urban infrastructure developments to be implemented with minimal scientific backing to support their success. In some cases this may directly impact a city’s ability to reach service delivery, economic growth and human development goals, let alone the city’s ability to protect ecosystem services upon which it relies. As an attempt to fill this gap, this paper describes an exploratory process used to determine city-level demographic, economic and resource flow data for African nations. The approach makes use of scaling and clustering techniques to form acceptable and utilizable representations of selected African cities. Variables that may serve as the strongest predictors for resource consumption intensity in African nations and cities were explored, in particular, the aspects of the Koppen Climate Zones, estimates of average urban income and GDP, and the influence of urban primacy. It is expected that the approach examined will provide a step towards estimating and understanding African cities and their resource profiles.

Applying the Hidden Markov Model to Analyze Urban Mobility Patterns: An Interdisciplinary Approach

With the emergence of the Internet of Things(IoT), there has been a proliferation of urban studies using big data. Yet, another type of urban research innovations that involve interdisciplinary thinking and methods remains underdeveloped. This paper represents an attempt to adopt a Hidden Markov Model(HMM) toolbox developed in Computer Science for the analysis of eye movement patterns in Psychology to answer urban mobility questions in Geography. The main idea is that both people’s eye movements and travel behavior follow the stop-travel-stop pattern, which can be summarized using HMM. Methodological challenges were addressed by adjusting the HMM to analyze territory-wide travel survey data in Hong Kong, China. By using the adjusted toolbox to identify the activitytravel patterns of working adults in Hong Kong, two distinctive groups of balanced(38.4%) and work-oriented(61.6%) lifestyles were identified. With some notable exceptions, working adults living in the urban core were having a more work-oriented lifestyle. Those with a balanced lifestyle were having a relatively compact zone of non-work activities around their homes but a relatively long commuting distance. Furthermore, working females tend to spend more time at home than their counterparts, regardless of their marital status and lifestyle. Overall, this interdisciplinary research demonstrates an attempt to integrate spatial, temporal, and sequential information for understanding people’s behavior in urban mobility research.

Anthropogenic disturbance of aquatic biodiversity and water quality of an urban river in Penang, Malaysia

Malaysia's rapid economic and demographic development have placed negative pressure on its water supplies and the quality of the Juru River, which is close to the nation's capital and its major source of water. Healthy aquatic ecosystems are supported by physicochemical properties and biological diversity. This study evaluated the anthropogenic impacts on aquatic biodiversity, especially plankton, fish, and macrobenthos, as well as the water quality of the Juru River in the Penang area. Aquatic biodiversity and river water parameters were collected from ten sampling stations along the Juru River. Seven variables were used to assess the physicochemical environment: pH, temperature, total suspended solids (TSS), salinity, dissolved oxygen (DO), biochemical oxygen demand (BOD), and chemical oxygen demand. At each sampling station, the total number of plankton, fish, and macrobenthic taxa were counted and analyzed. The relationships between the physicochemical parameters and aquatic biodiversity were investigated with biotypological analysis, principal component analysis, hierarchical cluster analysis, and linear regression analysis. These analyses showed that the richness and diversity indices were generally influenced by salinity, temperature, TSS, BOD, and pH. The data obtained in this study supported the bioindicator concept. The findings, as they related to scientifically informed conservation, could serve as a model for Juru River management, as well as for river management throughout Malaysia and other tropical Asian countries.

城市洪涝风险的多方法组合评估与应用

近年来,受全球气候变化与城镇化快速发展的双重影响,城市极端降水事件频发,由此引发的城市洪涝灾害常造成灾难性的生命和财产损失,给城市公共安全带来了严重威胁。由于不同评估方法中指标赋权不同,评价结果往往存在较大差异,给风险评估与区划工作带来了诸多困难。因此,通过融合不同方法的权重构建一套复合权重,进而解决不同评估方法中结论非一致性的问题,这对于提升风险评估的准确性是至关重要的。该文以湖北省为例,旨从危险性、暴露性、脆弱性和恢复性四个层面构建城市洪涝风险评估体系。首先,分别采用熵权法和层次分析法计算指标权重;之后,通过Kendall检验判断两套权重序列的一致性并给出相应的复合权重计算结果;最后以湖北省下辖8个城市的历史洪涝事件为例,对上述风险评价结果进行了验证。结果显示,与熵权法和层次分析法相比,基于复合权重的组合评价方法具有更高的准确率。

How to Improve Urban Competitiveness

Urban competitiveness has been the hot topic for researches and studies over years. The aim of this paper is to elaborate urban competitiveness. First, definition of competitiveness is discussed in detail and then the differences of competitiveness of nations and enterprises are presented. In Section 2, urban competitiveness is defined. Since the assessment of urban competitiveness is the focus of many studies, Section 3 elaborates four models or frameworks for assessing urbancompetitiveness. Last, but by no means the least, Chengdu has been discussed as a case on how to improve urban competitiveness. Three suggestions are put forward, which are clustering strategy, more efficient governance and urban marketing campaigns respectively.