Evolution of the“Golden Royal City”:Analytical study on urban forms of ancient capital cities in Myanmar

The historical cities in Southeast Asia with distinct characteristics are an important part of Asia’s cultural heritage system and the ancient capitals of Myanmar are as an example of these civilizational achievements.Their urban forms through history are essential spatial carriers reflecting the traditional local planning thinking.However,the overall understanding has yet to form due to a lack of systematic research.This study aims to complement it by studying the urban forms of almost all Myanmar’s ancient capitals based on verifiable spatial elements,works of literature,archaeology documents and field survey.The location,boundary and layout elements are analyzed to classify and characterize these urban forms,and their evolution rules are then summarized.Furthermore,the urban planning characteristics are discussed,indicating that the regulated structure and distinctive image gradually formed,accompanied by increasingly mature planning thinking and methods.The study reveals that the urban form and the planning thinking of Myanmar’s ancient capital cities had undergone an evolution with its own characteristics and that the“Golden Royal City”is of unique value in the genealogy of Asian capitals.The findings will contribute to the mutual learning between civilizations and provide a scientific foundation for the heritage conservation.

Urban Dynamics and Emergence of New Centers in the Dakar Region (Senegal)

Due to the status of the Dakar region as the former capital of AOF (French West Africa) and current capital of the Republic of Senegal, it is home to a very large part of the population and most of the socio-economic, administrative and cultural activities on a very small area of the country (0.28%). This situation makes it a very attractive region and subject to strong land pressure. The objective of this article is to study past and current urban dynamics as well as changes in natural spaces, in order to identify new urban centers. The methodological approach consists in analyzing satellite images to understand the evolution of different forms of spatial occupation in the Dakar region, and to study population movement flows and urban forms in order to reveal new urban centers. The results of the study show that the Dakar urban space is characterized by diverse forms which express a heterogeneous set of spaces. They also revealed the emergence of new clusters between 1986 and 2016, notably Ngor, Grand Yoff, Parcelles Assainies in the North-West, and Keur Massar and the North of the communes of Rufisque in the eastern part of the Dakar region.

Spatiotemporal Differentiation of Urban Spatial Form and Carbon Emissions in Poyang Lake City Group

In response to the inherent requirements of low-carbon land spatial planning in Jiangxi Province and the lack of existing research,this paper explored the mechanism of spatial form elements of Poyang Lake urban agglomeration on urban carbon emissions.Based on generalized linear regression and geographically weighted regression models,this paper analyzed the spatiotemporal distribution characteristics of carbon emissions,the spatiotemporal relationship between urban form index and carbon emissions,and the spatial differentiation of the intensity of dominant factors from 63 county-level administrative units in the Poyang Lake city group from 2005 to 2020.The results showed that:①The carbon emissions of urban agglomerations around Poyang Lake are generally increasing,and the spatial distribution of carbon emissions is characterized by high-value concentration in the middle and low-value agglomeration in pieces;②The main driving factor for the spatial heterogeneity of carbon emissions was the expansion of built-up area;③Improving urban compactness and optimizing urban form could effectively reduce urban carbon emissions.The results showcased the correlation between urban spatial landscape pattern and the spatiotemporal distribution of carbon emissions,which could make the low-carbon land spatial planning in the Poyang Lake city group more reasonable and practical.

Urban Spatial Form Optimization Strategies Based on the Principle of Climate Adaptability of Regional Architecture: A Case Study of Traditional Cave Dwelling Villages in Northern Shaanxi Province

A multitude of climate-adaptive design approaches are embedded in regional architecture,which have a positive impact on addressing the deformed development of urban spatial patterns and the dual challenges of climate and resources.This paper examines the principles of climate adaptability embedded in the site layout and spatial organization characteristics of traditional cave dwelling villages in northern Shaanxi Province.The extracted climate adaptability principles are summarized,and the resulting design strategies that are well-suited to the contemporary urban space form are presented.Through analysis,it can be observed that traditional cave dwelling villages in northern Shaanxi are predominantly situated on south-facing slopes in proximity to water at low altitudes.These villages are characterized by compact building groups and east-west development,which is constrained by the elements of mountains and rivers.A two-level street system is generated,comprising streets parallel to the contour line and roadways perpendicular to the contour line.This results in the formation of a courtyard form enclosed by mountains.Such site layout and spatial organization exhibit excellent climate adaptability with regard to heat,ventilation,and wind storage.In light of the aforementioned considerations,the following urban spatial form design strategies are put forth:①the topographic height difference can be exploited to obtain sufficient sunshine;②the group shape can be optimized in order to reduce building energy consumption;③the best orientation of the building can be chosen to take account of both winter and summer conditions;④the height and length can be combined in order to form natural masking;⑤the D/H ratio of streets and roadways should be controlled to achieve a balance between heat gain and cooling of groups;⑥vents should be set appropriately to optimize group ventilation;⑦climate buffers should be established to increase the level of climate response.

Construction of a refined population analysis unit based on urban forms and population aggregation patterns

The population analysis unit(PAU)is the basic unit employed in studies of urban populations.The commonly used PAUs are mostly administrative divisions,regular geographic grids.However,these units are different from urban forms,and cannot be used to consider the characteristics of population distributions and flow changes.In this study,we proposed a method for constructing a fine population analysis zone(FPAZ)based on the population aggregation pattern and urban form elements.First,considering the spatial structure of a city and the fine-grained demands of population analysis,the basic analysis unit was divided according to the functional heterogeneity of the population activity region at the micro-scale by combining urban form elements.Next,a population aggregation preference model was established by considering the spatial distribution characteristics of the local aggregation of the urban population flow and long-term stability characteristics depending on the dynamic changes in entrances and exits.Finally,we divided the FPAZ combined with the microstructural elements.Experimental results showed that compared with other types of PAUs,the FPAZ was more consistent with the urban morphology and was an appropriate and general spatial unit for expressing the accurate characteristics of population distributions and changes at the micro-scale.

Urban growth dynamics and expansion forms in 11 Tanzanian cities from 1990 to 2020

With rapid urban expansion across Tanzania,there is a need to institute steps to address factors and forms as well as impacts and challenges associated with the observed trend.This study’s aim is to use spatial urban landscape indices to analyze the spatial changes in urban forms,patterns,and rates across 11 urban centers in Tanzania over a 30-year study period(1990–2020).During the past three decades,urban lands of 11 cities and town in Tanzania have grown by a total of 480 km2.Leapfrog growth was found as the most dominant form of urban expansion in Tanzania while Dodoma,the capital city of Tanzania,had the highest rate of urban expansion when compared to all other individual cities.The most robust and significant interaction of the AWMLEI and MLEI was found in Kigoma,Arusha,Mtwara,Mafinga,and Tunduma cities.In contrast,Mbeya agricultural city,Arusha the tourist city,Tabora,and Geita Lake zone areas did show their own peculiarities revealing an interesting spatial temporal variation in rate and form of expansion.The outcome of this study reveals that the influence and management of economic and socio-cultural opportunities will be an effective tool for the determination of the rapidly expanding cities and towns of Tanzania.

Building Height Trends and Their Influencing Factors under China’s Rapid Urbanization:A Case Study of Guangzhou,1960–2017

Understanding the spatiotemporal patterns of three-dimensional urban forms,especially building height,can have important implications for improving urban air quality and mitigating the urban heat island effect by optimizing urban planning and management policies.This study investigated building height evolution and its influencing factors over approximately half a century(1960–2017)in Guangzhou,China.The results indicated that the logarithmic declines in height,quantity,and area of urban buildings followed Zapf’s law,which restricts the three-dimensional shape of the urban form.The urban building height decreased from the center to the periphery of the city and decreased with decreasing altitude and increasing distance from main roads.These characteristics constituted the three main spatial differentiation rules of building height in the central district of Guangzhou,and all exhibited a logarithmic decrease,which gradually strengthened over time.The development of a double-layered height structure of low-rise and high-rise buildings between 1990 and 2017 was a notable manifestation of the increase in vertical urban height over time.The three factors of city center,altitude,and accessibility,which represent centrality,low relief,proximity to water,and proximity to road networks,highlighted the roles of traffic accessibility and commercial attraction in building height evolution.The importance of location macroscopically depends on the combined effect of the geographical pattern,urban planning,and market forces of cities located on a plain near hill or by a river.The principle of profit orientation restricted spatiotemporal building height patterns.

Toward forest ‘‘sprawl'':monitoring and planning a changing landscape for urban sustainability

The present study analyzes the structure and dynamics of the forest landscape in a peri-urban area （Rome, Italy） during the city＇s expansion from 1949 to 2008 using landscape metrics and change detection anal- ysis of digital maps of the area （1500 km2）. While urban settlements increased continuously from 6.5 to 27.5 % of the study area, woodlands changed less clearly, with a moderate increase （from 11.2 to 11.9 % of the total area） and a higher fragmentation as a consequence of Rome＇s expansion. The structure of forest landscape changed along the urban-to-rural gradient with patch size increasing with the distance to the inner city in 1949 and substantial landscape homogeneity in 2008. The indicators proposed in this study inform dedicated measures for conserving forest and maintaining landscape diversity. Measures adopted in Rome＇s forestation plan to counteract woodlandfragmentation were analyzed and discussed. Based on the complex landscape dynamics found for Rome, an inte- grated multiscale planning approach targeting forest con- servation is considered a key contribution to urban sustainability.

Renewal of Urban Industrial Zone and Spatial Game in China:A Case Study of Chengdu Eastern Suburb Industrial Zone

The change of system constantly reshapes the urban form of China after 1949,among which the renewal and transformation of industrial zones is a typical phenomenon in the changing process of urban landscape in recent years,which centrally refl ects the development characteristics of contemporary Chinese cities under new social background.From the perspective of spatial game,this paper takes Chengdu Eastern Suburb Industrial Zone as an example,studies and interprets the changes of urban form and the causes of these changes in the renewal process of the industrial zone on the basis of the existing morphological frame and material landscapes,so then shows the particularity and complexity of the process of urban spatial reconstruction with current Chinese characteristics.

Urban Sprawl and Fertile Agricultural Lands in Iranian Cities Case Study： Tehran and Karaj

The phenomenon of disproportional expansion of urbanized areas into undeveloped area or ＂urban sprawl＂ has become a very a remarkable characteristic of urban development worldwide in the last decades. Urban sprawl is the popular media as the source of numerous social, environmental, and economic ills. One of the most evident consequences of urban sprawl is destroying agricultural lands around cities. One of the extreme expanded cities in Iran is Tehran megalopolis and cities around it. Tehran is expanding in all dimensions especially toward western side where Karaj city is located. The area of study for this research is Tehran and Karaj cities where the event of urban sprawl is happening. Materials used for achieving goal are aerial photographs, satellite images, thematic map of degree of soil and GIS software. The result of analysis shows that Tehran area has expanded from 10000 in 1956 to 80835 hectares in 2006. Area of Karaj city increased from 125 to 26000 hectare in the same period and the population density of two cities together decreased from 116 to 43 people per hectare. Sixty five percent of areas of these two cities are consisted of good fertile agricultural lands with irrigation potential. Twenty four percent of this land （14900 hectares） is classified as rank or class 1, 38.1 percent （23725 hectares） has rank 2, and 37.9 percent （23605） has rank 3 in terms of fertile land. Based on soil class and potential of production of wheat, it is estimated that if urban sprawl and expansion of these cities decreased or the direction of expansion changed to unfertile lands （class 4, 5 and 6）, and the cultivation of land had continued, 270,000,000 kilos of wheat could be produced yearly. So, urban sprawl is seen as one of the potential challenge to urban sustainable development and cannot be urban sustainable form.

Nonlinear relationship between urban form and transport CO_(2)emissions:Evidence from Chinese cities based on machine learning

Reducing carbon emissions from the transport sector is essential for realizing the carbon neutrality goal in China.Despite substantial studies on the influence of urban form on transport cO_(2)emissions,most of them have treated the effects as a linear process,and few have studied their nonlinear relationships.This research focused on 274 Chinese cities in 2019 and applied the gradient-boosting decision tree(GBDT)model to investigate the nonlinear effects of four aspects of urban form,including compactness,complexity,scale,and fragmentation,on urban transport CO_(2)emissions.It was found that urban form contributed 20.48%to per capita transport CO_(2)emissions(PTCEs),which is less than the contribution of socioeconomic development but more than that of transport infrastructure.The contribution of urban form to total transport CO_(2)emissions(TCEs)was the lowest,at 14.3%.In particular,the effect of compactness on TCEs was negative within a threshold,while its effect on PTCEs showed an inverted U-shaped relationship.The effect of complexity on PTCEs was positive,and its effect on TCEs was nonlinear.The effect of scale on TCEs and PTCEs was positive within a threshold and negative beyond that threshold.The effect of fragmentation on TCEs was also nonlinear,while its effect on PTCEs was positively linear.These results show the complex effects of the urban form on transport CO_(2)emissions.Thus,strategies for optimizing urban form and reducing urban transport carbon emissions are recommended for the future.

Exploring impact of street layout on urban flood risk of people and vehicles under extreme rainfall based on numerical experiments

Urban street layout is an important factor in the formation process, characteristics, and risk level of urban flooding;therefore, this study numerically investigates the impact of street layout on urban flood risk to people and vehicles. Four typical street-layout scenarios with areas of 3 km × 3 km are established based on a block-scale investigation. The layout types are regular grid,irregular grid, radial, and annular. Urban inundation models are then constructed for these typical street layouts based on the twodimensional(2D) hydrodynamic method. Two historic, extreme rainfall events, which occurred in Beijing on July 21, 2012 and in Zhengzhou on July 20, 2021, are used as rainstorm scenarios for urban inundation modelling. The flood risks to people and vehicles are then calculated. Results show that, for an extreme rainstorm on the block scale, the street layout impacts the spatial and temporal distributions of the inundation variables, which include the water depth, flow velocity, flood volume, and inundated area. Moreover, for the same extreme-rainfall scenario, the greatest differences in the total flood volume, maximum street-water depth, and maximum street-flow velocity caused by street-layout differences are 17.22%, 60.25%, and 61.50%, respectively.Among the four street layouts considered in this study, the annular street layout exhibits the lowest degrees of inundation and flood risk. For the same extreme-rainfall scenario, the proportions of high-risk road sections for adults and children in this layout are 58.89% and 62.28% smaller than those for the layout with the largest proportion of high-risk road sections, respectively;the proportions of high-risk road sections for the Honda Accord and Audi Q7 were 55.31% and 53.04% smaller, respectively. The findings of this study may aid scientific understanding and development of “flood-sensitive” block-scale street layouts and urban planning in the context of the changing environment.

Exploring the factors affecting urban ecological risk:A case from an Indian mega metropolitan region

Assessment of ecological risk(ER)is a key approach to adapting and mitigating ecological deterioration in cities of developing countries.In developing countries,the ecological landscapes such as vegetation cover,water bodies,and wetlands are highly vulnerable due to rapid urban expansion.Therefore,urban ER(UER)assessment and its drivers are crucial to guide ecological protection as well as restoration.This study aims to explore the spatiotemporal pattern of UER and the impact of urban spatial form on UER in the Kolkata Megacity Region(KMR),India.This study developed a UER index and used spatial regression models across the urban centres.The ER has been assessed at city scale as well as grid-scale(2 km x 2 km and 5 km x 5 km)from 2000 to 2020.The results showed that ER has substantially increased over the last 20 years.The urban centres with very high and high ER substantially increased,i.e.from 21.95%in 2000 to 31.70%in 2020.Kolkata and its surrounding urban centres were mostly characterized by very high and high ER.ER was influenced by spatial variables(such as land use and landscapes pattern).However,remote sensing parameters were weakly related to ER.The spatial lag model(SLM)(R^(2)=0.8686)was found to be better fit model than spatial error model(SEM)(R^(2)=0.8661)and ordinary linear regression model(OLS)(R^(2)=0.8641).Thus,the findings of the study can improve research and a comprehensive framework for urban ecological resources and provide a scientific basis for urban ecosystem planning and restoration.In addition to this,it will guarantee the sustainable utilization of urban ecosystems.

Joining Paths and Dividing Paths： Juiz de Fora, Brazil

The aim of this paper is to present the urban history of Juiz de Fora, a city with some 500,000 inhabitants in southeastern Brazil, and discuss how strategic decisions about the planning and construction of roads and highways can determine ways of life in a city. While paths may integrate landholdings and territories, they may also segregate communities and environments, causing deep rifts in the fabric of urban and land areas. The growth of Juiz de Fora is particularly marked by the construction of paths. This article reviews the local urban history from the establishment of paths in the city, to an analysis of the major impact and benefits they have had, notably on the local economy and demographics, as well as on the conservation of the local environment： Issues that are frequently relegated to a secondary role in the cost-benefit analysis of the city＇s planning decisions. After analysis of the case study, the authors concluded that citizens should be included on the agenda of the city, from spectators to actors of daily urban life.

Optimization Design of Open Spaces Based on Wind Tunnel and CFD Simulation： Case Study of a Street Canyon in Northern China

Airflow in open spaces can significantly affect spatial quality. Therefore, according to the type of building structures, the airflow also has different forms. Studies have been conducted on the relation between airflow and pedestrian comfort; however, only few of them have focused on comprehensive urban planning that considers different weather conditions and people＇s ability to adapt. This research focuses on the differences in wind conditions caused by different spatial forms in different seasons. On the basis of a field survey in both summer and winter in a public open space, evaluation standards developed from environmental meteorological data and public feedback were used to evaluate simulation results. Next, several assumptions about canyon orientation and building types were proposed. Wind tunnel and CFD （computational fluid dynamics） simulations were conducted to evaluate the assumptions. The results showed that the canyon orientation significantly affected overall wind conditions and different building structures affected airflow. This research also provides a method to evaluate urban areas that have complicated wind environments.

Rediscovering a Forgotten City： The Case Study of Laranjeiras

The term ＂forgotten city＂ was mentioned by researchers to denominate some colonial Brazilian settlements and cities which seem to have the same characteristics that demonstrate they were hidden along the years and that have the same atmosphere as they used to in their past life, i.e., they have the same traditional type of urban configuration produced at the origin of the city. This paper brings into discussion this character of this city, using as an example the city of Laranjeiras, one of the oldest cities of the State of Sergipe, which had a great and rich trade of sugar, besides significant cultural and political activities, being known as ＂Brazilian Athens＂ in the 19th century. Then, Laranjeiras decayed and stopped growing along the 20th century. However, it has had a good perspective to develop again with insertion of new different activities recently. The initial Portuguese planning to villages in Brazil followed specific rules and had a systematic assistance, what discards the myth that many Brazilian cities were born and grown up as a spontaneous form without planning. Studying some factors deeply, as spatial configuration, settlement localization and urban grid, it can be possible to point some recognizable elements which demonstrate that some cities were built to be forgotten. The methodology used for the analysis of Laranjeiras presents many historic, economic and cultural aspects related to the spatial-syntactic studies （Space Syntax Theory）, bringing to light some interesting thoughts about urban form and social life.

Assessing outdoor air quality vertically in an urban street canyon and its response to microclimatic factors

The vertical distribution of air pollutants in urban street canyons is closely related to residents’health.However,the vertical air quality in urban street canyons has rarely been assessed using field observations obtained throughout the year.Therefore,this study investigated the seasonal and annual concentrations of particulate matter(PM2.5 and PM10),CO,NO_(2),SO_(2),O_(3),air quality index,and their responses to microclimatic factors at three height levels(1.5,27,and 69 m above street level)in an urban street canyon.The PM concentration was higher at 27 m than at 1.5 m in winter,whereas the situation was reversed in other seasons.It was found that photochemical pollutants such as NO_(2) and O_(3) were the primary pollutants in the urban street canyon.The days on which O3 was the primary pollutant at the height of 1.5 m accounted for 81.07% of the entire year.The days on which NO_(2) was the primary pollutant at the height of 27 and 69 m accounted for 82.49% and 72.33%of the entire year,respectively.Substantially higher concentrations of NO2 and O_(3) were found at the height of 27 m than at 69 m.In-canyon concentrations of NO_(2) and O_(3) were strongly correlated with air temperature,wind speed,and wind direction,which played important roles in photochemical reactions and pollutant dispersion.

Street network patterns for mitigating urban heat islands in arid climates

This study explores the impact of street pattern measurements on urban heat islands(UHI)in the arid climate of Mashhad,Iran.The Landsat-8 top-of-the-atmosphere(TOA)brightness images from 2013 to 2021,average values of normalized difference vegetation index(NDvI)and land surface temperature(LST)were calculated.Street pattern measurements,including closeness-centrality,straightness,and street orientation,were employed to analyse the patterns in each district.The results indicated that districts with higher straightness and lower closeness-centrality exhibit,cooler surface temperatures.Strong correlations were observed between LST and NDVl,straightness,and local closeness-centrality.The research highlighted the importance of considering street network measurements in long-term urban planning and design to mitigate the UHI effect in arid regions.A moderate grid street pattern with a reasonable distribution of green spaces throughout the region is suggested to reduce surface temperatures sustainably.Street pattern indexes,such as straightness and local closeness-centrality,are identified as significant factors in urban design to mitigate UHl.These findings have implications for urban planners,who can use this information to create street network patterns with lower UHI effects by reducing local closeness-centrality and increasing straightness.

Beijing Urban Development Model:Urban Growth Analysis and Simulation

Urban growth analysis and simulation have been recently conducted by cellular automata （CA） models based on self-organizing theory which differs from system dynamics models. This paper describes the Beijing urban development model （BUDEM） which adopts the CA approach to support urban planning and policy evaluation. BUDEM, as a spatio-temporal dynamic model for simulating urban growth in the Beijing metropolitan area, is based on the urban growth theory and integrates logistic regression and MonoLoop to obtain the weights for the transition rule with multi-criteria evaluation configuration. Local sensitivity analysis for all the parameters of BUDEM is also carried out to assess the model＇s performances. The model is used to identify urban growth mechanisms in the various historical phases since 1986, to retrieve urban growth policies needed to implement the desired （planned） urban form in 2020, and to simulate urban growth scenarios until 2049 based on the urban form and parameter set in 2020. The model has been proved to be capable of analyzing historical urban growth mechanisms and predicting future urban growth for metropolitan areas in China.

Realizing the Box-counting Method for Calculating Fractal Dimension of Urban Form Based on Remote Sensing Image

In the research of fractal cities, the fractal dimension is very important. It is used to describe the fractal character of the city. The authors have designed two approaches to calculate the fractal dimension by the box-counting method through an example of Beijing, which are called the vector method and the grid method, respectively. The former calculates the fractal dimension through an intersecting analysis in ArcView; and the latter is carried out by programming in Matlab. They are compared from three aspects： the calculating process, the limits in use, and the results. As a result, the conclusion is made that there are merits and faults on both methods, and they should be chosen to use properly in practical situation.