THE EVOLUTION OF CHINESE DANWEI SYSTEM AND ITS INFLUENCE ON PLOT DEVELOPMENT: THE CASE OF NANJING

Proceedings of the XXV ISUF International Conference “Urban Form and Social Context: from Traditions to Newest Demands” (Krasnoyarsk, July 5–9, 2018)Social and economic policy has a profound influence on urban form development, besides urban planning, urban coding and site indicate. With different backgrounds of social and economic policies, the managements of urban development are discrepant, thus the outcomes of urban form are diverse. In New China after 1949, the state chose the Danwei System as a social organization form, and at the same time, the land utilization planning system was chosen as the land management policy. This made China’s urban construction management and urban form development proceeded on a unique road: instead of plot development, danwei actually acted as the carrier of urban development. Taking Workers’ Cultural Palace as a typical case, located in central district of Nanjing City, this paper illustrated its nine stages of plot development from 1946 till 2017. The transformation processes have revealed the intimacy with relevant social and economic managements in China. The detailed analysis has interpreted unique relationship between the danwei development and national guideline, national economic planning, land disposition system and urban planning. Through a profound and overall investigation, specific way of social influence on plot development in Nanjing can be proved. At the same time, this paper presents meaning transformation of some important elements, such as plot, in the process of urban form configuration in China, which eventually further deepen the understanding of present tangible form

A Tentative Approach to Mapping Street Space: A Case Study of Chinese Central Urban Districts

This paper focuses on exploring a quantitative approach to mapping street space. Characteristics of street space can hardly be described and explained using only the traditional architectural forms of street space. The difficulty arises because of the lack of relevance between these forms and people’s activities in them.This phenomenon presents a challenge to mapping methods. Expanding mapping elements is one viable and ongoing path. Which element could be an effective one and how it should be measured and mapped, are vital questions. Interface signs have been selected as the experimental elements, with an area of central Nanjing selected as the research sample.Database and statistics of interface signs and pedestrian flows have been established and inserted into the GIS (Geographical Information System) where a series of correlation analyses between basic mappings and pedestrian flows are carried out

Evaluation of Generating Mechanism of Residential Building Patterns in Contemporary Cities – Case Study on Xi’an and Nanjing

[EN] Residential area occupies a large portion of urban land, so it is very important to understand the characteristics of the residential building patterns and how such patterns, normally parallel multi-story and high-rise slab apartments in various cities of China, are formed. The residential building patterns are according to the living behavior, climate consideration, environmental requirement and market demands. Our previous studies have shown that sunshine regulation is by far the most important factor in the generation of the residential building pattern since 1980. This paper attempts to make a comprehensive evaluation to see the generating mechanism of the residential morphological patterns. Ten residential plots from two cities located in different climate zones of Xi’an and Nanjing are evaluated. Five factors, namely, the type of the apartment, plot FAR, land coverage, sunshine regulations and spatial characteristics of plot pattern, will be used as comprehensive evaluation indicators in the comparison. The study reveals how these factors interplay in the generation of the observed plot patterns and which factor is most important in this process. If the sunshine regulations were the key factor, how different the plot patterns in different climate zones and latitudes would have varied. Through evaluating generating mechanism we could find out the key generating factors, which is useful as the references for design.This study was financially supported by National Natural Science Foundation of China (No.51538005).Li, R.; Tang, L.; Ding, W. (2018). Evaluation of Generating Mechanism of Residential Building Patterns in Contemporary Cities – Case Study on Xi’an and Nanjing. En 24th ISUF International Conference. Book of Papers. Editorial Universitat Politècnica de València. 331-341. https://doi.org/10.4995/ISUF2017.2017.5920OCS33134

Ventilation Potential Assessments for Residential Building Arrangements Based on Exceedance Probability Analysis

In this study, the building ventilation potentials were assessed at building group level. Exceedance probability analysis was applied to estimate the uncertainties associated with the influence of climate on wind environment. The criterion was proposed based on building facade pressures. Tw o typical residential building arrangements were investigated. Simulation results show that facade pressure based exceedance probability are efficient in assessing the natural ventilation potentials of building groups and building height variations are important for improving building natural ventilation potentials

Identify Urban Spatial Patterns Based on the Plot Shapes and Building Setting in Downtown of Nanjing

[EN] he geometric characteristics of modern cities have been difficult to describe that is important for urban design, which deserve to be further interpreted. Taking advantage of Conzen’s methodology, the building is tightly related with its plot, which means the certain building pattern can be described by examining the generation of the building arrangement within the plot. Simultaneously, the building pattern is highly affected by the plot pattern it is located. In view of these, plot patterns together with land property and site coding could be taken as the clue for understanding both building patterns and urban spatial configuration. 35 commercial blocks in Nanjing downtown areas are chosen as research samples. Firstly, the internal structure of the blocks will be studied by analyzing the patterns, functions and land utilities of its plots. Focusing on the site coding and regulation, the building arrangement could be clarified and mapped. The results will identify the urban spatial patterns in downtown of Nanjing by mapping the characteristics of plot size, shape, properties and boundary lines. Therefore, the method on describing urban spatial configuration in modern cities could be developed.This research is funded by National Natural Science Foundation of China (No. 51538005).Gu, Y.; Tang, L.; Ding, W. (2018). Identify Urban Spatial Patterns Based on the Plot Shapes and Building Setting in Downtown of Nanjing. En 24th ISUF International Conference. Book of Papers. Editorial Universitat Politècnica de València. 1431-1437. https://doi.org/10.4995/ISUF2017.2017.5924OCS1431143

An investigation on the quantitative correlation between urban morphology parameters and outdoor ventilation efficiency indices

Urban outdoor ventilation and pollutant dispersion have important implications for the urban planning and design of urban morphology. In this paper, two urban morphology parameters including Floor area ratio (FAR) and Building site coverage (BSC) are attempted to investigate the quantitative correlation with urban ventilation indices. Firstly, we present an idealized model including nine basic units. The FAR of model is constant 5.0, and the BSC increases from 11% to 77%, which in consequence generates 101 non-repetitive asymmetric forms. Next, the Computational Fluid Dynamics (CFD) is employed to evaluate the ventilation efficiency of pedestrian level within each model’s central area. Six indicators including air flow rate (Q), mean age of air (τp), net escape velocity (NEV), purging flow rate (PFR), visitation frequency (VF) and resident time (TP) are used to assess the local ventilation performance. Results clearly show that when the FAR of the plot is specified, the local ventilation performance does not present an obvious linear relationship. As the BSC increases, the ventilation in the central area does not keep reducing. On the contrary, some forms with low BSC have poor ventilation and some particular forms with high BSC have better ventilation performance. This shows that for an urban, it not always exists poor local ventilation under the high-density conditions. The local ventilation performance can be effectively improved by rationally arranging the architectural arrangement within the plot. These findings suggest a preliminary way to build up the correlation between urban morphology parameters and ventilation efficiency. Even though the application of these results to the real cities require further research, but for this paper, it presents a feasible framework to the urban designers

Morphological analysis: to evaluate the pattern of Residential building based on wind performance

[EN] Residential morphological patterns are reflection of people's living habits and tradition, local climate and building regulations, so that one of those factors could be studied through in order to understand residential morphological patterns. Based upon our previous study, we do know that in China living habits and local climate mainly influence the shape of residential buildings and apartment patterns, but we do not know whether the pattern of residential plots determined by FAR and sunshine hours are suitable for wind environment related to residential environmental quality. Therefore, it is very significant to evaluate wind environment within residential plots based on the apartment pattern controlled by various building codes. Our study focuses on the pattern of Slab apartments in Nanjing, which are mainly used in China, and selects 40 residential slices with different plot shapes, plot FAR, building heights and sizes. Based upon MATLAB, we have got all geometrical data between buildings among these slices to identify the spatial pattern character of each residential plot. Through evaluating wind environment of these slices by simulation we can obtain wind speed, pressure and age of air and choose the pattern of age of air as the main evaluation factor of wind performance. Correlation analysis will be made between the apartment patterns and pattern of age of air, by doing so, each typical space between buildings will be evaluated. Our study will reveal the relevance of apartment pattern and wind environment, which can be used to support and improve design in the future.Yang, Y.; You, W.; Peng, Y.; Ding, W. (2018). Morphological analysis: to evaluate the pattern of Residential building based on wind performance. En 24th ISUF International Conference. Book of Papers. Editorial Universitat Politècnica de València. 1461-1469. https://doi.org/10.4995/ISUF2017.2017.5977OCS1461146

A quantitative study of urban form and its spatial character

Understanding urban morphological processes can help architects and urban designers in urban design, especially in urban renewal projects. Since urban form and urban space are closely integrated, the morphological changing process inevitably causes changes in the spatial characteristics that are of concern to urban designers. This study focuses on analysing the relationship between the building interface and the space between buildings. We have made a tool to quantify the characteristics of urban space by setting viewpoints in the urban space, which can measure the distances and height angles from the viewpoints to the surrounding building interfaces. To verify the effectiveness of the tool, two urban areas in Nanjing are selected for case studies. One is an area located in the centre of the city that has undergone tremendous changes and has many high-rise buildings. The other is an area located in the historic conservation area that has changed little and has many traditional houses. Comparing the two areas with quantitative indicators of spatial characteristics, it is found that different urban forms have different spatial characteristics. Based on an in-depth study of the morphological evolution process and social background, four morphological periods are selected for the morphological study of the two areas. By comparing urban morphological processes and spatial characteristics changing process of the areas on the same timeline, the impact of urban morphological change on urban spatial characteristics in different areas and the role of spatial characteristics indicators are analysed. Comparing the two areas with quantitative indicators of spatial characteristics, it is found that different urban forms have different spatial characteristics. In the measurement of the area in the historic conservation area, some spatial indicators that can be used to control the spatial characteristics are found, which are useful for the urban renewal of the historical area