scholarly journals Discovering Urban Functional Polycentricity: A Traffic Flow-Embedded and Topic Modeling-Based Methodology Framework

2020 ◽  
Vol 12 (5) ◽  
pp. 1897
Author(s):  
Shaodong Wang ◽  
Yanbin Liu ◽  
Wei Zhi ◽  
Xihua Wen ◽  
Weihua Zhou
Keyword(s):  
Urban Planning ◽  
Traffic Flow ◽  
Urban Area ◽  
Traffic Control ◽  
Urban Areas ◽  
Topic Modeling ◽  
Spatial Organization ◽  
Rapid Development ◽  
Trajectory Data ◽  
Function Distribution

With the rapid development of communication and transportation technologies, the urban area is increasingly becoming an ever more dynamic, comprehensive, and complex system. Meanwhile, functional polycentricity as a distinctive feature has been characterizing urban areas around the world. However, the spatial structure of the urban area has yet to be fully comprehended from a dynamic perspective, and understanding the spatial organization of polycentric urban regions (PUR) is crucial for issues related to urban planning, traffic control, and urban risk management. The analysis of polycentricity strongly depends on the spatial scale. In order to identify functional polycentricity at the intra-unban scale, this paper presents a traffic flow-embedded and topic modeling-based methodology framework. This framework was evaluated on real-world datasets from the Wujiang district, Suzhou, China, which contains 151,419 records of taxi trajectory data and 86,036 records of points of interest (POI) data. This paper provides a novel approach to examining urban functional polycentricity via combining urban function distribution and spatial interactions. This proposed methodology can help urban authorities better understand urban dynamics in terms of function distribution and internal connectedness and facilitate urban development in terms of urban planning and traffic control.

scholarly journals Spectral Analysis of Traffic Functions in Urban Areas

2015 ◽  
Vol 27 (6) ◽  
pp. 477-484 ◽  
Author(s):  
Florin Nemtanu ◽  
Ilona Madalina Costea ◽  
Catalin Dumitrescu
Keyword(s):  
Spectral Analysis ◽  
Fourier Transform ◽  
Fourier Analysis ◽  
Traffic Flow ◽  
Traffic Control ◽  
Urban Areas ◽  
Urban Traffic ◽  
The Fourier Transform ◽  
The City ◽  
Different Time Scales

The paper is focused on the Fourier transform application in urban traffic analysis and the use of said transform in traffic decomposition. The traffic function is defined as traffic flow generated by different categories of traffic participants. A Fourier analysis was elaborated in terms of identifying the main traffic function components, called traffic sub-functions. This paper presents the results of the method being applied in a real case situation, that is, an intersection in the city of Bucharest where the effect of a bus line was analysed. The analysis was done using different time scales, while three different traffic functions were defined to demonstrate the theoretical effect of the proposed method of analysis. An extension of the method is proposed to be applied in urban areas, especially in the areas covered by predictive traffic control.

scholarly journals URBAN GROWTH AND WATER QUALITY IN THIMPHU, BHUTAN

2013 ◽  
pp. 82-95 ◽  
Author(s):  
Nandu Giri ◽  
O. P. Singh
Keyword(s):  
Water Quality ◽  
Urban Area ◽  
Water Samples ◽  
Urban Areas ◽  
Forest Cover ◽  
Rapid Development ◽  
Oxygen Demand ◽  
Capital City ◽  
Quality Data ◽  
Water Quality Data

Detailed study was undertaken in 2008 and 2009 on assessment of water quality of River Wang Chhu which flows through Thimphu urban area, the capital city of Bhutan. The water samples were examined at upstream of urban area, within the urban area and its downstream. The water samples were analyzed by studying the physico-chemical, biological and benthic macro-invertebrates. The water quality data obtained during present study are discussed in relation to land use/land cover changes(LULC) and various ongoing human activities at upstream, within the each activity areas and it’s downstream. Analyses of satellite imagery of 1990 and 2008 using GIS revealed that over a period of eighteen years the forest, scrub and agricultural areas have decreased whereas urban area and road network have increased considerably. The forest cover, agriculture area and scrub decreased from 43.3% to 42.57%, 6.88% to 5.33% and 42.55% to 29.42%, respectively. The LULC changes effect water quality in many ways. The water temperature, pH, conductivity, total dissolved solids, turbidity, nitrate, phosphate, chloride, total coliform, and biological oxygen demand were lower at upstream and higher in urban area. On the other hand dissolved oxygen was found higher at upstream and lower in urban area. The pollution sensitive benthic macro-invertebrates population were dominant at upstream sampling sites whereas pollution tolerant benthic macro-invertebrates were found abundant in urban area and its immediate downstream. The rapid development of urban infrastructure in Thimphu city may be posing serious threats to water regime in terms of its quality. Though the deterioration of water quality is restricted to a few localized areas, the trend is serious and needs proper attention of policy planners and decision makers. Proper treatment of effluents from urban areas is urgently needed to reduce water pollution in such affected areas to check further deterioration of water quality. This present study which is based on upstream, within urban area and downstream of Thimphu city can be considered as an eye opener.

Finding the right tree for future urban planning – Meso- to microscale model coupling in urban areas

2020 ◽  
Author(s):  
Joachim Fallmann ◽  
Helge Simon ◽  
Tim Sinsel ◽  
Marc Barra ◽  
Holger Tost
Keyword(s):  
Air Pollution ◽  
Urban Planning ◽  
Urban Area ◽  
Ozone Concentration ◽  
Tree Species ◽  
Urban Areas ◽  
Street Canyon ◽  
Model Systems ◽  
Traffic Load ◽  
Microscale Model

<p><span>It has been long understood that green infrastructure helps to mitigate urban heat island formation and therefore should be a key strategy in future urban planning practices. Due to its high level of heat resilience, the sycamore tree (Platanus) dominates the appearance of urban landscapes in central Europe. Under extreme climate conditions however, these species tend to emit high levels of biogenic volatile organic compounds (BVOCs) which in turn can act as precursors for tropospheric ozone, especially in highly NOx polluted environments such as urban areas. </span></p><p><span>Assessing the ozone air quality of a large urban area in Germany we use the state-of-the art regional chemical transport model MECO(n), with chemistry coming from the Modular Earth Submodel System (MESSy) and meteorology being calculated by COSMO. Including the latest version of TERRA_URB, the model is configured for the Rhine-Main urban area. In a second step, we implement parts of the regional atmospheric chemistry mechanism in the ENVI-met model framework in order to investigate the impact of isoprene emissions on ozone concentration at street level for the urban area of Mainz, Germany. </span></p><p><span>Whereas mesoscale model results only show moderate mean ozone pollution over the model area, at micro-scale level on selected hot spots we find a clear relationship between urban layout, proximity to NOx emitters, tree-species-dependent isoprene emission capacity and increase in ozone concentration. The ENVI-met study reveals, that next to tree species, its location is a key factor for its micro-climatic UHI and air pollution mitigation potential. We could show, that isoprene related ozone concentration is highly sensitive to leaf temperature, photosynthetic active radiation as well as to the proximity to NO2 pollution sources. In a street canyon with high traffic load we find significant correlations between diurnal boundary layer dynamics, morning and evening rush hour and ambient ozone levels. For a hot summer day in particular, we simulate ozone concentrations rising up to 500% within a weakly ventilated street canyon with a high amount of strong isoprene emitters being present.</span></p><p><span>We summarize that combining findings from meso- and microscale model systems can be an important asset for science tools for cities in the framework of climate change adaption and mitigation </span><span>and air pollution abatement</span><span> strategies.</span></p>

scholarly journals INTELLIGENT TRAFFIC CONTROL DEVICE MODEL USING AD HOC NETWORK

2019 ◽  
Vol 01 (02) ◽  
pp. 68-76
Author(s):  
Robert Bestak
Keyword(s):  
Traffic Flow ◽  
Automobile Industry ◽  
Traffic Control ◽  
Traffic Congestion ◽  
Urban Areas ◽  
Communication Systems ◽  
Ad Hoc ◽  
Road Traffic ◽  
Control Device ◽  
Device Model

The advancements in the technologies related to the wireless communication systems has made the vehicular adhoc networks prominent area of research in the automobile industry. The absolute volume of road traffic affects the safety, convenience and the efficiency of the traffic flow in the urban areas. So the paper scopes in developing an intelligent traffic control device model using the adhoc network to ameliorate the traffic flow. The proposed system enhances the convenience in travel by gathering the information of the vehicles along with the density of the vehicles and the movement of the vehicles on road. The device is modelled using the MATLAB and examined over the traffic flow on the peak hours as well as the normal hours and the holidays to understand its intelligent traffic control. The results obtained shows that the performance improvement in optimizing the traffic congestion through the proposed method is better compared to the existing methodologies used in traffic controlling.

scholarly journals Research on the Coupling Coordination Relationships between Urban Function Mixing Degree and Urbanization Development Level Based on Information Entropy

2020 ◽  
Vol 18 (1) ◽  
pp. 242
Author(s):  
Xuanxuan Xia ◽  
Kexin Lin ◽  
Yang Ding ◽  
Xianlei Dong ◽  
Huijun Sun ◽  
...  
Keyword(s):  
Urban Area ◽  
Information Entropy ◽  
Rapid Development ◽  
Trajectory Data ◽  
Spatial Entropy ◽  
Development Level ◽  
Urbanization Development ◽  
Urban Function ◽  
Degree Of Coupling ◽  
Coordination Degree

With the rapid development of urbanization, the blind expansion of urban space has led to a series of social problems. In this process, the degree of urban function mixing affects the urbanization development level, making it particularly important to study the degree of coupling coordination between the two aspects. In this paper, taking Beijing as an example, we use urban point of interest (POI) data and taxi GPS trajectory data to calculate the urban POIs’ spatial entropy and taxis’ temporal entropy, based on the information entropy. We use the POIs’ spatial entropy and taxis’ temporal entropy to measure the urban function mixing degree. Also, the model of coupling coordination degree is used to measure the degree of coupling coordination between the urban function mixing degree and the urbanization development level. The results indicate the following: First, the POIs’ spatial entropy and taxis’ temporal entropy have significant regional imbalances. On the whole, both show a declining pattern when moving from the central urban area to the outer suburbs. The urban function mixing degree and urbanization development level are also higher in the central urban area than in the outer suburbs. Second, the coupling coordination among the urbanization development level, POIs’ spatial entropy, and taxis’ temporal entropy is distributed unevenly across various regions, which means that the three types of coupling coordination are in balanced development in the central urban area, but in unbalanced development in the outer suburbs. Third, from the perspective of spatial correlation characteristics, the higher is the degree of spatial agglomeration, the higher are the urban function mixing degree and urbanization development level, and the higher is the coupling coordination degree among the urbanization development level, POIs’ spatial entropy, and taxis’ temporal entropy. Therefore, relevant departments should plan the construction of urban functional areas reasonably, according to the degree of coupling coordination between the urban function mixing degree and the urbanization development level in different regions, so as to realize the healthy and sustainable development of a city.

scholarly journals Urban Planning and Natural Hazard Governance

2019 ◽  
Author(s):  
Ricardo Marten ◽  
Theresa Abrassart ◽  
Camillo Boano
Keyword(s):  
Urban Planning ◽  
Urban Space ◽  
Urban Areas ◽  
Spatial Organization ◽  
Natural Hazard ◽  
Disaster Risk ◽  
Population Characteristics ◽  
Community Groups ◽  
Managing Risk ◽  
Inclusive Governance

The establishment of effective linkages between institutional urban planning and disaster risk strategies remains a challenge for formal governance structures. For governments at all administrative scales, disaster resilience planning has required systemic capacities that rely on structures of governance, humanitarian frameworks, and budgetary capacities. However, with growing urbanization trends, humanitarian responses and Disaster Risk Management (DRM) frameworks have had to adapt their operations in contexts with high population density, complex infrastructure systems, informal dynamics, and a broader range of actors. Urban areas concentrate an array of different groups with the capability of contributing to urban responses and strategies to cope with disaster effects, including community groups, government agencies, international organizations and humanitarian practitioners. In addition, cities have running planning structures that support their administration and spatial organization, with instruments that supply constant information about population characteristics, infrastructure capacity and potential weaknesses. Processes and data ascribed to urban planning can provide vital knowledge to natural hazard governance frameworks, from technical resources to conceptual approaches towards spatial analysis. Authorities managing risk could improve their strategic objectives if they could access and integrate urban planning information. Furthermore, a collaborative hazard governance can provide equity to multiple urban actors that are usually left out of institutional DRM, including nongovernmental organizations, academia, and community groups. Traditional top-down models can operate in parallel with horizontal arrangements, giving voice to groups with limited access to political platforms but who are knowledgeable on urban space and social codes. Their still limited recognition is evidence that there is still a disconnect between the intentions of global frameworks for inclusive governance, and the co-production of an urban planning designed for inclusive resilience.

scholarly journals MANAGING PHYSICAL DEVELOPMENT IN PERI-URBAN AREAS OF KUMASI, GHANA: A CASE OF ABUAKWA

2013 ◽  
pp. 96-109 ◽  
Author(s):  
Paul Amoateng ◽  
Patrick Brandful Cobbinah ◽  
Kwasi Owusu-Adade
Keyword(s):  
Urban Area ◽  
Urban Areas ◽  
Rapid Development ◽  
Growth Management ◽  
Physical Development ◽  
Urban Morphology ◽  
High Rate ◽  
Physical Growth ◽  
Secondary Sources ◽  
Study Approach

A remarkable trait of the 21st century has been the high rate of urbanization which has characterized the growth and development of cities especially in developing countries. This situation has fuelled the rapid and unguided development and expansion of peri-urban areas as urban dwellers relocate to cities’ peripheries. Focusing on Abuakwa a peri-urban area in Kumasi, the second largest city in Ghana, this paper assesses the nature and extent of physical development in peri-urban areas, and identifies the factors contributing to the rapid development of peri-urban areas. The paper further examines the effects of the increasing physical growth on the development of peri-urban Abuakwa. Using a case study approach, both primary and secondary sources of data were collected from decentralized government institutions of Kumasi Metropolitan Assembly (KMA) and Atwima Nwabiagya District Assembly (ANDA), as well as the indigenous residents and relocated urban dwellers in Abuakwa. The paper reveals that the outward drift has manifested itself in an increased scramble for land for residential and commercial purposes in the peri-urban area. The resultant effect has been the fast and spontaneous physical development in the urban periphery which has significantly altered the peri-urban morphology. The paper recommends the establishment of Customary Land Secretariat (CLS) and the application of settlement growth management approaches to ensure the creation of functional city and liveable peri-urban areas.

Traffic Control in Separation Schemes

1983 ◽  
Vol 36 (3) ◽  
pp. 445-453
Author(s):  
Włodzimierz Filipowicz
Keyword(s):  
Traffic Flow ◽  
Branch And Bound ◽  
Traffic Control ◽  
Rapid Development ◽  
Heavy Traffic ◽  
Optimal Solution ◽  
Separation Scheme ◽  
Computational Process ◽  
The World ◽  
Submerged Obstacles

The paper deals with the formulation and analysis of the problem of ship's traffic control in separation schemes. The branch and bound procedure has been used for optimal solution of the problem. The proof for a possible computational process is given together with the results of a numerical example.In view of the rapid development of the world merchant fleet the problem of safety at sea appears now as neither fully defined nor sufficiently analysed. Some measures and partial solutions to improve the safety of sea traffic have been suggested and implemented, e.g. in papers by Ciletti and Glas. As examples of such implementation one can mention traffic lanes, the calculation of separation-scheme optimal crossing angles, etc. In areas with heavy traffic where either natural constraints such as islands, submerged obstacles or traditional routes exist, all the separation lanes create sophisticated systems called traffic separation schemes. Many steps now being taken to improve safety of navigation are based essentially on traffic separation. Some innovations and improvements in designing the structures of the separation schemes must be taken into account. It seems that all such passive measures will be efficient up to natural limits connected with the magnitude of the traffic flow. In heavy traffic the author believes active control should be established.

scholarly journals EXPLORING THE POTENTIALS OF SMALL URBAN STREAMS IN CREATING BLUE-GREEN INFRASTRUCTURE IN THE CITY OF NIŠ, SERBIA

2020 ◽  
Vol 14 (1) ◽  
Author(s):  
Milena Dinić Branković ◽  
Milica Igić ◽  
Petar Mitković ◽  
Jelena Đekić ◽  
Ivana Bogdanović Protić
Keyword(s):  
Urban Planning ◽  
Urban Area ◽  
Natural Resource ◽  
Green Infrastructure ◽  
Urban Areas ◽  
Stormwater Management ◽  
Natural Capital ◽  
Cost Effective ◽  
Urban Streams ◽  
The City

“Blue-Green Infrastructure” (BGI) is a simple and cost-effective natural resource that enhances theappeal, resilience and sustainability of urban areas. Small urban streams are an important BGIcomponent that is often underused, especially regarding stormwater management. The aim of thisresearch is to explore small urban streams and their integration into BGI in the urban area of Niš,and to point out the benefits that their restoration would bring in functional, social and environmentalterms. Results of this study show that Niš urban area has significant “Blue” natural capital in smallstreams, and that standing planning documents support the creation of BGI to some extent. Theseare good grounds for the implementation of BGI in urban planning practice.

scholarly journals Análise da taxa de impermeabilização e tempo de concentração nas sub-bacias da área urbana de Barra do Garças – MT, Pontal do Araguaia – MT e Aragarças – GO

2015 ◽  
Vol 10 (1) ◽  
pp. 27
Author(s):  
G. B. M. Rezende ◽  
S. M. S. Araujo
Keyword(s):  
Land Use ◽  
Urban Planning ◽  
Urban Area ◽  
Urban Areas ◽  
Urban Expansion ◽  
Urban Drainage ◽  
Time Of Concentration ◽  
Relationship Of ◽  
The Relationship ◽  
Alternative Solutions

<p>A presente pesquisa objetivou verificar as taxas de impermeabilização e tempo de concentração das sub-bacias presentes na área urbana de Barra do Garças – MT, Pontal do Araguaia – MT e Aragarças – GO. Tais variáveis podem auxiliar no ordenamento territorial da expansão urbana, bem como no planejamento urbano dessas cidades. Os resultados demonstraram que nas áreas já urbanizadas, o grau de impermeabilização e tempo de concentração das sub-bacias apresentaram  níveis considerados “médios e altos”, o que é preocupante, devido a relação dessas variáreis ao crescimento das vazões e volume escoado, e, consequentemente, aumento da frequência de inundações. Medidas não-estruturais, como legislação de uso do solo, com regras e incentivo para aumento de áreas permeáveis em lotes, bem como implantação de soluções alternativas de drenagem urbana que promovam o retardamento das águas pluviais, são soluções que podem ser implementadas na área em estudo.</p><p align="center"><strong><em>Analysis of the waterproofing rate and time of concentration in urban sub-basins of Barra do Garças – MT, Pontal do Araguaia – MT e Aragarças – GO</em></strong></p><p><strong>Abstract</strong><strong>: </strong>This study aimed to verify the waterproofing rates and time of concentration of these sub-basins present in the urban area of Barra do Garças – MT, Pontal do Araguaia – MT e Aragarças – GO. Such variables can assist in land use of urban expansion and the urban planning of these cities. The results demonstrated that in urban areas already, the degree of waterproofing and time of concentration of the sub-basins presented levels considered "medium and high", which is worrying, because the relationship of these variables to the growth of flows and runoff, and, consequently, increased frequency of floods. Non-structural measures such as land use legislation, with rules and incentive to increase permeable areas on lots, and implementation of alternative solutions to urban drainage that promote the slowing of rainwater, are solutions that can be implemented in the study area.</p>

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