Urban Morphological Characteristics Research Articles

Analysis of the Spatial Distribution Pattern of the Urban Landscape in the Central Plains under the Influence of Multiscale and Multilevel Morphological Geomorphology

This paper presents an in-depth analysis and research on the spatial distribution pattern of the urban landscape in the Central Plains digital landscape form and proposes an optimization scheme. Based on the basic theories of systematics and complexity, this paper analyzes the self-similar characteristics of urban morphology, establishes the concept of schema, and constructs a multiscale and multilevel morphological map research framework by drawing on the “planar pattern” morphological analysis method of the school and the “matrix, patch, and corridor” spatial expression model of landscape ecology. The framework of morphological map research at multiple scales has been established, and the theory and method of describing, understanding, judging, and analyzing morphological evolution have been formed. Cities have self-similarity at different scales, and urban evolution is a process of recursion from small-scale hierarchy to large-scale hierarchy, and hierarchy is a phenomenon presented by the natural evolution of cities. After any morphological process is completed, it can only be transformed into the other two ways, so the static morphological description can be transformed into dynamic morphological process analysis.

Effects of neighbourhood morphological characteristics on outdoor daylight and insights for sustainable urban design

ABSTRACT Urban daylight significantly affects the physical and mental health of urban residents. Many previous studies focused on how outdoor daylight conditions affect indoor daylighting of buildings, whereas the design of outdoor daylighting conditions, which also exerted an equally significant part, was relatively overlooked. There are also few studies empirically explored the outdoor daylight in various forms of mature urban neighbourhoods. Through investigating the outdoor pedestrian daylight performances of 11 representative open urban neighbourhood units in inner-city Shenzhen, this study aims to identify the influence of urban design factors. Through field investigation, mapping and on-site measurement, this study explored and analysed the horizontal illuminance level and site illuminance uniformity of 84 outdoor spaces. As the results revealed, urban morphological characteristics significantly affected the daytime pedestrian illumination. Specifically, the high-density mid-rise urban villages and the urban park demonstrated the best daytime outdoor visual comfort conditions. The multivariate regression test demonstrated that sky view factor exerted the greatest influence on the daytime outdoor illumination, followed by the mean building height, ground surface albedo and vertical uniformity. Hence, urban morphological patterns have great potential in optimizing urban design for outdoor daylighting behaviours and energy use, which is of great reference value in setting specific standards to achieve the goals of the initiatives of “Healthy Cities.”

Influence of urban morphological parameters on the distribution and diffusion of air pollutants: A case study in China

Air pollution has a serious fallout on human health, and the influences of the different urban morphological characteristics on air pollutants cannot be ignored. In this study, the relationship between urban morphology and air quality (wind speed, CO, and PM2.5) in residential neighborhoods at the meso-microscale was investigated. The changes in the microclimate and pollutant diffusion distribution in the neighborhood under diverse weather conditions were simulated by Computational Fluid Dynamics (CFD). This study identified five key urban morphological parameters (Building Density, Average Building Height, Standard Deviation of Building Height, Mean Building Volume, and Degree of Enclosure) which significantly impacted the diffusion and distribution of pollutants in the neighborhood. The findings of this study suggested that three specific strategies (e.g. volume of a single building should be reduced, DE should be increased) and one comprehensive strategy (the width and height of the single building should be reduced while the number of single buildings should be increased) could be illustrated as an optimized approach of urban planning to relief the air pollution. The result of the combined effects could provide a reference for mitigating air pollution in sustainable urban environments.

Impacts of urban morphological characteristics on nocturnal outdoor lighting environment in cities: An empirical investigation in Shenzhen

Lighting is a vital environmental element that affects people's outdoor activities and the creation of liveable neighbourhoods in cities. The use of appropriate lighting at night in public spaces can benefit people's social well-being. This research examined the effects of urban morphological characteristics on outdoor night-time lighting behaviours by analysing 11 urban neighbourhoods that reflect the variety of the prevailing urban morphological patterns in the city centres of Shenzhen. A set of urban morphological descriptors were analysed and two lighting parameters were evaluated by on-site measurement. The results revealed that the low-density high-rise modern neighbourhoods presented very high outdoor illuminance levels, but extremely low occupant use at night, and consequently, remain significant potential of light pollution and energy waste. By contrast, urban villages with high-density mid-rise patterns possess limited outdoor lighting facilities but exhibited very high nocturnal neighbourhood vitality. This type of neighbourhood presents a “demand-oriented and energy-saving” lighting behaviour during the night-time through the use of light spill from the nearby indoor light sources. Multivariable linear regression indicated that morphological characteristics significantly contribute to the illumination distribution within urban spaces. Together, building coverage ratio, floor area ratio, tree coverage ratio and ground surface albedo explain 88% of the variability of night-time site illuminance uniformity. With adding the dimension of urban morphology, this research tries to extend the scope of urban nocturnal lighting studies and provides insights into the setting of more specific criteria for urban design, so as to contribute to healthy city initiatives.

The effect of urban morphological characteristics on the spatial variation of PM2.5 air quality in downtown Nanjing.

The effects of the urban morphological characteristics on the spatial variation of near-surface PM2.5 air quality were examined. Unlike previous studies, we performed the analyses in real urban environments using continuous observations covering the whole scale of urban densities typically found in cities. We included data from 31 measurement stations divided into 8 different wind sectors with individually defined morphological characteristics leading to highly varying urban characteristics. The urban morphological characteristics explained up to 73% of the variance in normalized PM2.5 concentrations in street canyons, indicating that the spatial variation of the near-surface PM2.5 air quality was mostly defined by the characteristics studied. The fraction of urban trees nearby the stations was found to be the most important urban morphological characteristic in explaining the PM2.5 air quality, followed by the height-normalized roughness length as the second important parameter. An increase in the fraction of trees within 50 m of the stations from 25 percentile to 75 percentile (i.e. by the interquartile range, IQR) increased the normalized PM2.5 concentration by up to 24% in the street canyons. In open areas, an increase in the trees by the IQR actually decreased the normalized PM2.5 by 6% during the pre-COVID period. An increase in the height-normalized roughness length by the IQR increased the normalized PM2.5 by 9% in the street canyons. The results obtained in this study can help urban planners to identify the key urban characteristics affecting the near-surface PM2.5 air quality and also help researchers to evaluate how representative the existing measurement stations are compared to other parts of the cities.

Estudos de morfologia como subsídio para a qualificação do espaço edificado

O estudo da morfologia pré-existente permite identificar padrões que se apresentam como insumos à formulação de regras volumétricas para as edificações. Sendo assim, propusemos uma metodologia de análise e classificação dos quarteirões por formato e dimensão, assim como do padrão de lotes e sistema viário subsequentes. O estudo permitiu identificar, a partir da aplicação ao estudo de caso de Passo Fundo, Brasil, 12 espaços morfológicos distintos e, assim, passíveis de serem adotados como base para regras urbanas: Quadrícula, Retangular tipo A, Retangular tipo B e Retangular tipo C; que se apresentam em superfícies pequenas, médias e grandes. Os resultados apontaram que: (a) quarteirões quadrados condicionam fortemente o formato e dimensão dos lotes subsequentes; (b) quarteirões retangulares não condicionam o formato dos lotes; (c) existe uma correlação entre frequência de redes viárias e disposição central do loteamento e uma correlação inversa entre dimensão do quarteirão e frequência de redes viárias.

Urban Tissue of Traditional Chinese and Southeast Asian Port Cities: The Influence of Maritime Trade

In the process of urban development and regeneration, a city always gradually derives multiple morphological characteristics from its original single form. The transformation of urban form can be viewed as representation of consequence of overlapping of cultural attributes, an urban quality which is often ignored by property developments. This paper addresses that culture is a starting point to analyze traditional urban forms of Chinese and Southeast Asian traditional port cities. On the one hand, it analyzes their urban morphological characteristics focusing on the urban tissue level, which can reflect a process of urban evolution based on multi-culture brought by the ancient maritime trade. On the other hand, four port cities with similar cultural attributes including Quanzhou and Guangzhou in China, Hanoi in Vietnam and Malacca in Malaysia are analyzed comparatively to demonstrate their morphological differences and similarities. Based on the analysis of the two aspects, the paper recovers the relationship between cultural attributes and urban morphology, as well as some universal and special rules of urban development.

Evaluating the performance of a novel WUDAPT averaging technique to define urban morphology with mesoscale models

The definition of accurate input datasets, appropriately representing urban morphology characteristics, has been identified as a crucial point for improving the simulation of urban boundary layer (UBL) dynamics by means of mesoscale numerical weather prediction (NWP) models. However, the scarcity of suitable data to adequately describe urban morphology is in many cases a significant obstacle to overcome. For this purpose, the World Urban Database Portal Tool (WUDAPT) framework was developed in order to obtain a standard classification of urban morphology, even in the absence of ad-hoc data for any city.In the present work, a modified WUDAPT method to define urban morphology is proposed and compared with two state-of-the-art methods, i.e. the standard WUDAPT method and a urban morphology parameters obtained from LIDAR data. In particular, here morphological features of Local Climate Zones (LCZs), resulting from a 30-m resolution WUDAPT classification, are interpolated to NWP cells, providing averaged features of the urban morphology. In this way, the method produces a unique value of the different urban morphology parameters for each model cell. This technique is tested by means of simulations with the Weather Research and Forecasting (WRF) model at 500 m resolution for the city of Bologna (Italy), located in the Po Plain. Simulation output is compared with measurements from weather stations. Results show that simulations using the modified WUDAPT method reproduce better atmospheric dynamics with respect to those implementing the standard WUDAPT method, and are comparable with simulations using the urban morphology defined with LIDAR data, considered as reference. In particular, the most relevant improvements are found in areas where LCZs are more heterogeneous and where the boundary between rural and urban areas is not clearly defined. It follows that the use of this method improves the classic WUDAPT method for small and scattered cities with respect to large and clustered urban areas, and can be particularly useful for urban areas where detailed LIDAR data are not available.

A Methodological Analysis Approach to Assess Solar Energy Potential at the Neighborhood Scale

Rapid and uncontrolled urbanization is continuously increasing buildings’ energy consumption and greenhouse gas emissions into the atmosphere. In this scenario, solar energy integrated into the built environment can play an important role in optimizing the use of renewable energy sources on urban surfaces. Preliminary solar analyses to map the solar accessibility and solar potential of building surfaces (roofs and façades) should become a common practice among urban planners, architects, and public authorities. This paper presents an approach to support urban actors to assess solar energy potential at the neighborhood scale and to address the use of solar energy by considering overshadowing effects and solar inter-building reflections in accordance with urban morphology and building characteristics. The approach starts with urban analysis and solar irradiation analysis to elaborate solar mapping of façades and roofs. Data processing allows assessment of the solar potential of the whole case study neighborhood of Sluppen in Trondheim (Norway) by localizing the most radiated parts of buildings’ surfaces. Reduction factors defined by a new method are used to estimate the final solar potential considering shadowing caused by the presence of buildings’ architectural elements (e.g., glazed surfaces, balconies, external staircases, projections) and self-shading. Finally, rough estimation of solar energy generation is assessed by providing preliminary recommendations for solar photovoltaic (PV) systems suited to local conditions. Results show that depending on urban morphology and buildings’ shapes, PV systems can cover more than 40% of the total buildings’ energy needs in Trondheim.

Using the waste Kuznet's curve to explore regional variation in the decoupling of waste generation and socioeconomic indicators

Decoupling of resource consumption from economic growth is a key principle in the transition towards a circular economy. This study explores regional variation in the decoupling of waste generation from mean income in the Australian state of New South Wales (NSW), following the Waste Kuznet's curve (WKC) hypothesis. The WKC hypothesis tests for the existence of a relationship between waste and economic indicators conforming to an inverted-U shape that may indicate decoupling. A geographically and temporally weighted regression (GTWR) model is used to test the WKC hypothesis for municipal waste from 2011 to 2015. We identify municipalities conforming to the WKC hypothesis, and examine the socioeconomic and urban morphological characteristics of these municipalities. Results show that waste policy must be targeted to consider local variability in socioeconomics. Municipalities across rural NSW were found to conform to the WKC over the time frame. WKC-conforming municipalities had higher per-capita rates of waste generation, and lower mean incomes compared to non-conforming municipalities. Ratios of tipping point (global maximum) to mean income for WKC conforming municipalities were estimated between 0.8 and 2, indicating that these municipalities are in stages of relative, rather than absolute, decoupling. This study demonstrates the application of the WKC for examining decoupling, and highlights the importance of considering variations in regional characteristics when assessing the decoupling of waste generation from income. Findings also broadly suggest regionally specific policy making is required for circular economy transitions in NSW.

The effect of building height and façade area ratio on pedestrian wind comfort of London

The evaluation of wind environment has been receiving increasing attention as it has been associated with issues related to the quality of the urban climate, such as heat island intensity and air pollution, affecting health and wellbeing in large metropolitan areas. Focusing on the context of London, this study aims to associate pedestrian level wind comfort with the characteristics of urban morphology that incorporate information about the height variability and the vertical dimensions of buildings. More than 20 case studies of different configurations and dimensions 500 × 500 m were examined through CFD simulations. For each case study, eight wind directions were tested and the BRE wind comfort criteria were implemented for the different outdoor human activities. The results reveal a strong connection between the ground level mean wind speed ratio and the development of acceptable or tolerable wind conditions for pedestrians. From the morphological indicators examined, façade area ratio was the most dominant on mean wind speed ratio and on the percentage of outdoor space which is comfortable for certain activities, especially for increasing values of plan area ratio. The results of the study indicate that façade area ratio should be taken into consideration for assessing pedestrian level wind environment.

Allometric Relations of Sycamore Maple (Acer pseudoplatanus) and its Red Leaf Cultivar (A. pseudoplatanus“Atropurpureum”) in Street and Park Habitats of Novi Sad (Serbia, Europe)

Adaptability and allometric relations of Acer pseudoplatanus and A. pseudoplatanus “Atropurpureum” at different urban sites are investigated in this work via the diameter at breast height (dbh), tree height, and crown width measurements, which served as ordinary least-squares regression model inputs. Differences between A. pseudoplatanus and A. pseudoplatanus “Atropurpureum,” as well as intraurban variations of trees growing at different urban site categories (park and street) and location in the same urban site category with different urban morphology characteristics, were noted. The strongest allometric relations were noted for crown width/tree height and tree height/dbh. Higher uniformity and better linear model fit were obtained for A. pseudoplatanus “Atropurpureum.” Based on allometric relations with dbh as the predictor variable, trees growing in parks were shorter and had a wider crown than street trees, whereas the same tree proportions were observed in A. pseudoplatanus.

Analysis of spatial and seasonal distributions of air pollutants by incorporating urban morphological characteristics

Due to the worldwide trend of industrialization and urbanization, air pollutants were emitted heavily on a global scale particularly in developing countries, which produces adverse effects on human health by causing health problems such as respiratory and lung diseases. Many regression models based on land use types and urban fabrics have been built to analyze the spatiotemporal distribution of air pollutants, however, few of them examined the relationship between urban morphological characteristics and the distribution of air pollutants in a megacity. This study investigates such relationships for six types of air pollutants (PM2.5, PM10, SO2, NO2, O3, and CO) and a composite AQI (Air Quality Index) based on hourly data at 35 monitoring stations in Beijing in 2016, with morphological characteristics (Morphological building index), meteorological factors (Land Surface Temperature, LST), land use (vegetation, road length, gas station and industry point data), and population distribution data. We also analyzed the results with spatiotemporal regression and SSH (Spatial Stratified Heterogeneity) models respectively. According to the spatiotemporal regression model, the morphological building index (MBI) shows a strong correlation with the dispersion of PM2.5 (R2 = 0.81) and AQI (R2 = 0.80) in the warm season and this finding was reinforced through the Leave-one-out-cross-validation (LOOCV) analysis. From the SSH analysis, the road length in a large proximal region impacts air pollutants the most, especially for O3; and population density significantly affects PM 2.5, AQI, SO2, and NO2 in the cold season. From an integrated interpretation, distance to nearest industry impacts the spatial distribution of NO2 in cold season, while it impacts that of PM2.5 and AQI in both warm and cold seasons. The research finds that these two models supplement each other well and together help to give us a better understanding of how air quality is affected in the urban landscape.

Hierarchical Merging & Generalization Method of Three-Dimension City Model Group Based on the Theory of Spatial Visual Cognition

In order to simplify the three-dimensional building group model, this paper proposes a clustering generalization method based on visual cognitive theory. The method uses road elements to roughly divide scenes, and then uses spatial cognitive elements such as direction, area, height and their topological constraints to classify them precisely, so as to make them conform to the urban morphological characteristics. Delaunay triangulation network and boundary tracking synthesis algorithm are used to merge and summarize the models, and the models are stored hierarchically. The proposed algorithm should be verified experimentally with a typical urban complex model. The experimental results show that the efficiency of the method used in this paper is at least 20% higher than that of previous one, and with the growth of test data, the higher efficiency is improved. The classification results conform to human cognitive habits, and the generalization levels of different models can be relatively unified by adaptive control of each threshold in the clustering generalization process.

Evaluating retrofit options in a historical city center: Relevance of bio-based insulation and the need to consider complex urban form in decision-making

Historical dwellings make up a significant fraction of the French building stock and require substantial retrofitting to reduce their energy consumption and improve their thermal comfort. In the city center of Cahors, France, the old medieval dwellings are considered as valuable cultural heritage and internal insulation is often the only insulation technique that can be used when the architectural value of the exterior façade is to be preserved. However, internal insulation may have an impact upon the hygrothermal performance of the wall, leading to lowered drying capacity, with possible interstitial condensation and mold growth. Hygrothermal models may be used to assess the risk of failure, but the accuracy of the results depends on how reliable the input data is, including external boundary conditions, which may vary significantly in dense medieval cities such as Cahors. In this study, a Geographical Information System model of Cahors is used to develop EnergyPlus models of individual dwellings. The boundary conditions output by these models are, in turn, used to model the hygrothermal performance of façades with different internal insulations, using the hygrothermal tool Delphin. The Delphin outputs are then analyzed with the VTT model, a mold growth assessment model. Results highlight a quantitative correlation between some urban morphology characteristics and the hygrothermal performance of refurbished walls, with some configurations raising the risk of damage patterns. We find that bio-based insulation presents a better hygrothermal performance than mineral wool in most of the configurations.

High-resolution dataset of urban canopy parameters for Beijing and its application to the integrated WRF/Urban modelling system

The Weather Research and Forecasting (WRF) model with urban canopy model has been widely used to study atmospheric boundary layer processes and urbanization-related environmental issues. One of the most daunting challenges faced by the integrated WRF/urban modelling system is constraining the uncertainties in urban canopy parameters (UCPs) that represent the urban morphological characteristics. In this paper, we develop a dataset of three-dimensional (3-D) UCPs for Beijing by using vector-format building information in a Geographic Information System (GIS) environment and apply it to the integrated WRF/urban modelling system to investigate the effects of UCPs on the simulated meteorological variables against observations in clear-sky days. Moreover, the role of spatially-varying UCPs involved in the Building Effect Parameterization (BEP) in capturing the heterogeneous characteristics of 2-m surface air temperature and 10-m wind field in the urban areas are evaluated. In general, high-resolution dataset of UCPs improves the model skill in simulating the diurnal variations and spatial distributions of 2-m surface air temperature and 10-m wind speed in the urban canopy, especially for the BEP. WRF/BEP with gridded UCPs dataset shows a better performance in densely built-up areas, where the morphological and physical characteristics of urban surface are complex. It also performs better in capturing the characteristics of urban heat islands (UHIs) and weak wind zones (WWZs) in urban areas. Results show that introducing the 3-D UCPs dataset into the integrated WRF/urban modelling system is a simple and yet efficient way to enhance the modelling capabilities in urban areas and assist urban planners to deal with urban environmental issues.

Local climate zone classification with different source data in Xi’an, China

The city’s local climate zone (LCZ) has been considered as a useful guiding tool for urban climate mapping and classification of urban canopy in cities. However, the LCZ classification methods and results are different in different cities in different countries and regions. Therefore, it is necessary to conduct a targeted research that would take into account local urban morphology and canopy characteristics. In the current work, a LCZ classification method is proposed. This would provide a useful guide for city planning and operation. In the newly proposed method, the LCZ types were first adjusted, according to the characteristics and urban morphology of Chinese cities, in relation to existence of high- and low-rise buildings and high density residential population and land cover of greeneries. Based on investigations of two LCZ classifications of the City of Xi’an, a coupling method was proposed. This method couples the World Urban Database and Access Portal Tools method based on remote sensing data with the classification method based on road network divided by land parcels. The proposed method was validated in this study against the actual land use and construction data that were surveyed in Xi’an, which showed acceptable accuracy. Our results have illustrated the feasibility of our proposed classification for urban LCZ mapping in China.

The potential of local climate zones maps as a heat stress assessment tool, supported by simulated air temperature data

High population densities in cities and rapid urban growth increase the vulnerability of the urban environment to extreme weather events. Urban planning should account for these extreme events as efficiently as possible. One way is to locate hot spots in an urban environment by mapping cities into local climate zones (LCZ) and evaluate heat stress related to these zones. LCZs are likely to become a standard in urban climate modelling as they capture important urban morphological characteristics. For instance, temperature regimes linked to spatially explicit LCZ maps should be assessed for all LCZ zones derived from these maps. This study assesses the thermal behavior of mapped LCZs using simulated temperature data from the UrbClim model. Prior to temperature analysis, the model was validated with observational data. To evaluate the robustness of the analysis, we ran the model in three cities in Belgium: Antwerp, Brussels, and Ghent. The results show that temperature regimes are significantly different for all the built zones in the urban environment independent of the city. Second, the susceptibility to heat stress can differ greatly depending on the zone. The unique thermal behavior of the different LCZs provides indispensable information on the urban environment and its climatic conditions. This study shows that the LCZ scheme has a potential to help urban planners globally tackle adverse effects of extreme weather events.

Neighborhood Variation of Sustainable Urban Morphological Characteristics.

Compact cities and their urban forms have implications on sustainable city development because of high density urban settlement, increased accessibility, and a balanced land use mix. This paper uses quantitative means of understanding urban morphological characteristics with reference to the differing qualities of the urban form (i.e., street patterns, building volumes, land uses and greenery). The results, based on 89 neighborhood communities of Hong Kong, show varying degrees of regional differences in the urban built form supported by numerical statistics and graphical illustrations. This paper offers empirical evidence on some morphological characteristics that can be estimated objectively using modern geospatial technologies and applied universally to inform urban planning. However, more studies linking these quantifiable measures of the physical form with sustainable urban living are needed to account for human comfort in the totality of environmental, social, and economic responsibilities.

城市空间形态离散度指数NDIS构建与应用

PDF HTML阅读 XML下载 导出引用 引用提醒 城市空间形态离散度指数NDIS构建与应用 DOI: 10.5846/stxb201711031967 作者: 作者单位: 中国科学院城市环境研究所, 中国科学院大学,中国科学院城市环境研究所,中国科学院上海分院 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金面上项目（41471137）；国家自然科学基金重点项目（71533003） Study on the formulation and application of the urban spatial form dispersion index (NDIS) Author: Affiliation: Institute of Urban Environment,Institute of Urban Environment, Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:中国土地资源有限，需要可持续的、紧凑的城市空间形态与布局，因此，全面度量城市空间形态的紧凑性具有重要意义。通过6个情境分析了离散度指数DIS的优缺点，识别出DIS值在反映城市形态紧凑程度方面的不足，进而提出了一种新的城市空间形态紧凑度指数，即标准化离散度指数NDIS。NDIS不受城市面积规模的影响，且具有唯一性，利于城市紧凑度的横向和纵向比较，能更好地指示城市空间形态。NDIS值越大，城市越离散。进一步将NDIS与成熟使用的标准化紧凑度指数NCI结合，用于分析中国35座城市的空间形态紧凑性，研究结果表明：（1）NDIS最大值是兰州市的1.64，最小值是石家庄市的1.14，均值1.29±0.12（SE）；NCI最大值是郑州市0.39，最小值是宁波市的0.1，均值0.24±0.07（SE）；（2）NDIS与NCI虽然具有中等程度的相关性（r=-0.44，P < 0.01），但是NDIS把城市斑块间的距离关系表达得更为准确；（3）将NDIS与NCI结合，能够更加全面地指示城市空间形态的紧凑程度。准确、全面的衡量中国城市的空间形态，则需要与更多的景观格局指数结合使用。 Abstract:Chinese cities need a sustainable, compact spatial layout. Therefore, comprehensive measurement of the urban spatial form is of great significance. This paper introduces the degree of dispersion (DIS), assesses the advantages and disadvantages of DIS through 6 situations, and identifies the deficiency of DIS value in reflecting the compactness of urban morphology, and then put forward a new compact index to assess urban spatial form, that is, the normalized dispersion index NDIS. NDIS is not affected by the size of the urban area, and the city has a unique value, which is conducive to the horizontal and vertical comparison of urban compactness. The greater the NDIS value, the more discrete the city is. Furthermore, NDIS is combined with the normalized compactness index NCI to analyze the compactness of 35 cities in China. The results show that:(1) The maximum NDIS value for the investigated 35 cities is 1.64, the minimum is 1.14, and the average is 1.29 ±0.12 (SE). (2) Values of NCI ranges between 0.1-0.39, with an average of 0.24 ±0.07 (SE). (3) NDIS and NCI have a moderate degree of correlation (r=-0.44, P < 0.01), but NDIS is more accurate in expressing the distance between urban patches. (4) The correlation shows that the two indices have partially overlapping information, but the difference can better highlight the urban morphological characteristics. Of course, NDIS is not a perfect index to measure the urban spatial morphology. A more accurate and comprehensive measurement of the spatial patterns of Chinese cities requires the combination of more landscape metrics. The next step in research would be to focus on combining compactness indices with urban structure and environmental factors to find out the suitable ranges for Chinese cities and provide a guideline for the construction of the compact city, sustainable city, and low carbon city. 参考文献 相似文献 引证文献