Urban Structure Research Articles

A new approach for quantification of total above-ground heartwood and sapwood volume of trees

Key messageTerrestrial laser scanning data of trees combined with models of heartwood content proportion of woody disks can provideprecise characterization of total aboveground tree sapwood and heartwood volume.Quantifying sapwood and heartwood content of trees is challenging. Previous studies have primarily characterized main stem wood composition, while branches have rarely been studied. Terrestrial Laser Scanning (TLS) can provide precise representations of the entire above-ground tree structure, non-destructively, to help estimate total tree sapwood and heartwood volume. In this study, we used TLS to scan above-ground portions of twenty-four open-grown, urban Gleditsia triacanthos trees on Michigan State University campus. TLS data were used to generate quantitative structure models that provided comprehensive characterizations of the total tree woody surface area (WSA) and volume. A subsample of trees was harvested (after scanning) and main stem and branch woody disks were collected to build models of heartwood content proportion. Models were applied to measurements from TLS to quantify complete heartwood and sapwood volume of each tree, including main stem and branches. From the base to the top of the trees, the largest portion of stem vertical cumulative volume was heartwood, whereas vertical cumulative volume of branches showed the opposite pattern. Absolute heartwood volume declined monotonically toward zero from stem base to stem top, while absolute sapwood volume declined sharply from stem base up to near the crown base and then remained relatively constant within crown. We also found that tree WSA increased with sapwood volume for both branches and main stem. This study developed a novel, general method for quantifying total aboveground sapwood and heartwood volume of trees and provided new insights into urban tree growth and structure.

Assessing the impact of greenery on urban heat using opportunistic drive-by sensing

The urban heat island (UHI) phenomenon is recognized as a main urban sustainability problem in the face of a changing climate, affecting human health, energy consumption, and other socio-economic considerations. The UHI can be mitigated by urban greenery, but it needs further investigation of detailed impacts across the urban landscape. The aim was to study UHI and model the relation to greenery in combination with urban grey structures, at a high spatiotemporal resolution across the urban landscape, in Stockholm. Temperature data was collected through opportunistic drive-by sensors on electric three-wheeled taxis. Data on greenview and skyview factors were used to inform on greenery and building density along the roads. During night and morning hours, the surface temperature was in general higher than air temperature, indicating that some densely built-up environments stored heat overnight. Hot zones were unevenly distributed throughout the city, while greenery had a cooling effect, especially when combined with skyview as an inverse measure of building density. Our results provide information on the spatiotemporal distribution of heat that can be used to inform efforts to use greenery for mitigating impacts of UHI on urban residents.

Timber Biogenic Carbon Stock in the Urban Environment: Santiago City as a Second Forest

Urban environments significantly contribute to carbon emissions, both through operational processes and the embodied emissions of construction materials, thus exacerbating climate change. Nevertheless, urban timber structures offer a viable alternative by acting as carbon sinks, capable of sequestering carbon for decades or even centuries. This study develops and applies a methodology to quantify the biogenic carbon stored in Santiago City’s timber-based buildings, conceptualized as a “Second Forest” that transfers and preserves the carbon capture capacity of trees in the built environment. The analysis estimates that Santiago’s urban timber constructions have expanded their wood-built surface area by 192,831 m2 over the past eight years, reflecting the growing adoption of timber in urban construction. During the same period, biogenic carbon storage increased from 199.78 kt to 202.73 kt, equivalent to 10.84 kt of CO2 under average conditions. These findings highlight the potential of urban planning strategies, such as promoting taller timber buildings and adopting circular timber practices, to enhance carbon sequestration and reduce reliance on carbon-intensive materials. This research highlights the fundamental role that timber buildings play in urban climate change mitigation, positioning them as active contributors to global carbon management efforts.

Contributions to Architectural and Urban Resilience Through Vulnerability Assessment: The Case of Mozambique Island’s World Heritage

Mozambique Island, a UNESCO World Heritage property, faces significant challenges due to climate change and extreme weather events. This study proposes a comprehensive framework for assessing morphological vulnerabilities and enhancing urban resilience in this unique historical urban landscape. The research methodology involves a thorough analysis of historical cartography, urban evolution, topography, and vernacular architecture, combined with recent conservation assessments and case studies from other climate-vulnerable regions. This study reveals the island’s dual urban structure, comprising the Stone and Lime town and the Macuti town, each with distinct morphological characteristics and vulnerabilities. Historical maps and topographical analysis demonstrate how the island’s geography has shaped its urban development, with the Stone and Lime town built on higher ground and the Macuti town situated at or below sea level, increasing its flood risk. The research highlights the importance of integrating traditional knowledge with resilience strategies while respecting the authenticity and integrity of the World Heritage property. Key findings include the need for a GIS-based management tool for continuous conservation assessment, and the crucial role of community engagement in implementing resilience mechanisms. This study contributes to the broader discourse on cultural heritage as a contributor to architectural and urban resilience, offering valuable insights for other World Heritage properties facing similar climate challenges. The proposed framework emphasizes the importance of balancing heritage preservation with adaptive strategies, while enhancing the island’s resilience facing climate-related threats.

Value of Colonial Architectural Heritage for Sustainable Tourism Promotion in Center of Thakhek City

This research aims to study the value of the colonial architectural heritage in the center of the old town of Thakhek to promote sustainable tourism with an emphasis on historical, cultural and economic values. The research method is document survey and field survey to present information on the value of colonial architectural heritage in descriptive and analysis method. The results of the study found that 1) Historical, cultural and social values, 2) The value of urban planning and urban structure, 3) Architectural and scenic value, 4) Architectural heritage value and 5). The value of using and promoting heritage and cultural tourism. The research also proposes a way to promote sustainable tourism that involves the participation of all relevant parties including the local community, government agencies and tourism businesses, implementing environmental policies, promoting cultural preservation, supporting the local economy, create sustainability certification standards for tourism businesses, monitor and evaluate economic, social and environmental impacts and create awareness campaigns. The research highlighted the importance of preserving colonial buildings in order to promote tourism, increase cultural identity, and promote economic development. This study has contributed to the understanding of colonial architectural heritage preservation and the impact of sustainable development in the region.

Shade watch: Mapping citywide shade dynamics through ray tracing and LiDAR data in Hong Kong's complex 3-D built environment

The importance of urban shade in city planning has been underscored by its various associations with thermal comfort, living environment quality, human health and well-being. However, existing methods for urban shade mapping are often limited to street-level scopes or singular sampling observational times, leaving citywide shade mapping, its spatiotemporal patterns, and controlling factors largely unexplored. To fill these knowledge gaps, this study proposed a novel protocol that enables seamless mapping of spatiotemporal urban shade patterns over the entire city by fusing look-up-table (LUT)-based ray-tracing approach with Google Earth Engine cloud computing technology, as well as high-resolution digital surface model (DSM) derived from LiDAR data. This protocol was applied to Hong Kong, a city characterized by a complex 3-D built environment, and then delved into the spatiotemporal patterns of urban shade and the associated controlling factors. Validation results indicate that the proposed method can accurately quantify urban shade compared to ground-based photo references and high-resolution satellite imagery. The analysis uncovers that: (1) Shade exhibits spatial heterogeneity across different 3-D built environments while maintaining a consistent "U-shape" diurnal shade fraction during the day; (2) Solar geometry, regardless of solar zenith and azimuth angle, is positively associated with aggregated metrics of shade landscape and negatively associated with fragmented metrics. Moreover, solar zenith angles exert stronger controls over the citywide shade landscape patterns; and (3) Persistent shade significantly reduces the sunlight hours (i.e., the accumulated sunshine hours per day) across administrative districts, local climate zones (LCZs), and seasons. Due to shade effects originating from 3-D urban structures, Hong Kong typically experiences an average of 4-8 sunlight hours per day within a one-year cycle, which is substantially lower than the 11-14 hours of natural daylength. This study offers a practical protocol for large-scale urban shade mapping, enhancing our understanding of urban shade, its spatiotemporal dynamics, and benefits in a broader spatiotemporal context. The associated datasets and findings from this study can inform urban planners and policymakers in developing effective strategies to create healthier and sustainable urban environments in Hong Kong.

Mapping urban green structures using object-based analysis of satellite imagery: A review

Mapping urban green structures using object-based analysis of satellite imagery: A review

Spatiotemporal characteristics and influencing factors of non-CO2 greenhouse gas emission intensity from China's livestock sector.

The livestock sector is a major source of non-CO2 greenhouse gas (GHG). As China has the world's largest livestock production, analyzing factors influencing GHG emission intensity of livestock (GEIL) is crucial for guiding its emission reduction policies. Yet, most current studies on livestock GHG focus on emission amount (GEAL) over GEIL, neglecting comprehensive utilization of spatial econometric models. Furthermore, the influencing factors mainly focus on population, economic level, urbanization, and industrial structure, while the exploration of factors such as technological innovation, consumers' age structure, and industrial agglomeration remains insufficient. This study first applied the standard deviation ellipse (SDE) model to describe the spatiotemporal evolution of GEAL and GEIL across 31 Chinese provinces from 2006 to 2022. Then, using extended STIRPAT theory, we analyzed GEIL's influencing factors with exploratory spatial data analysis (ESDA) and the geographically and temporally weighted regression (GTWR) model. The results showed that: (1) GEAL was concentrated in resource-rich grassland pastoral and grain-producing areas. Provincial GEAL trends varied, while national GEAL declined rapidly and then fluctuated slightly. Cattle, pigs, and sheep/goats contributed the most to GEAL. (2) GEIL significantly decreased nationwide and provincially, with Tibet having the highest reduction rate but still leading in GEIL. (3) GEAL followed a northeast-southwest distribution, whereas GEIL exhibited an east (slightly north) to west (slightly south) pattern. (4) Spatial analysis revealed significant GEIL clustering, with higher values in western provinces and lower in central and eastern regions. (5) Population scale, urbanization, age structure, proportion of ruminant animal production value, location quotient of livestock, employment income per capita of agricultural personnel, patent-granted intensity, and educational level in rural areas had diverse spatiotemporal impacts on GEIL across provinces. Tailored emission reduction policies and regional collaborative governance are recommended.

Impact of Regional Structure and Topography on the Effectiveness of Public Transportation Services

This study investigates the impact of urban structure and topography on public transportation effectiveness in developing countries. Using structural equation modeling analysis of survey data from 500 public transit users across five diverse cities, we examine how these geographical factors influence accessibility, reliability, comfort, and user satisfaction. Results indicate that both urban structure and topography significantly affect transportation effectiveness, with urban structure having a slightly stronger influence. Polycentric urban designs and moderate topography were associated with higher public transit effectiveness. User perceptions highlighted the importance of integrated planning approaches. The findings suggest policymakers should consider geographical contexts when designing public transportation systems, potentially through adaptive infrastructure and context-specific service models. This research contributes to a more nuanced understanding of public transit planning in varied urban environments of developing nations.

Occupational diversity in Chinese cities: facts, evolution and policy implications

<div><p>Measuring the occupational diversity and trend of Chinese cities from the perspective of the distribution of urban occupational types, and discussing the impact of urban characteristics on urban occupational diversity can provide reference for guiding urban full and high-quality employment. By using the improved Herfindahl index, panel data fixed effect model and Oaxaca blinder decomposition, it is found that the occupational diversity in Chinese cities showed a trend of first decreasing and then increasing from 2002 to 2016, which was due to the adjustment of urban industrial structure and the emergence of new economy after the financial crisis; at the same time, the larger the city, the higher the administrative level and the more developed the economy, the higher the degree of occupational diversity. The conclusion of the study is helpful to intuitively understand the occupational distribution, industrial structure and division of labor in different cities, evaluate the human resource structure and economic development potential of cities, and then provide policy suggestions for different cities to formulate industrial development and human resource planning.</p></div>

Comparison of urban planning governance structures in London and Paris through case analysis

Comparison of urban planning governance structures in London and Paris through case analysis

Building Detection and Outlining in Multi-Modal Remote Sensor Data: A Stratified Approach

Exploitation of aerial sensor data for vectorized representation of urban structures is of great importance for urban modeling. Even if elevation data is available, extracting complex and irregular building shapes would become challenging. In this paper, we present a stratified approach for the extraction of building outlines consisting of two steps: Classification and vectorization. For classification, we use training data transfer to evaluate a dataset with no or little labeled data. Since the available reference data is also flawed, we use a self-developed interactive tool to adjust and improve the building shape before contrasting it with the classification results. Initial building polygons are slightly generalized and refined considering building shape characteristics. Hereby, Least-Squares adjustment is implemented to solve the best-fit problem of building edges with the input data by applying the Gauss-Helmert and Gauss-Markov Models. On the raster level, the resulting polygons achieved an accuracy of over 99% in the Potsdam dataset and almost 98% in the Munich dataset while on the vector level, the median building-wise deviations lie in sub-meter range. Although there were few mis-detections and, sometimes, considerable peak deviations for the Hausdorff distance, the compelling qualitative results attest to the robustness and validity of the proposed procedure.

A Study on Planting Techniques to Enhance the Function of Urban Wind Ventilation Forest: In the Case of Wind-Connecting Forest, Seocho-gu, Seoul

Background and objective: This study was conducted to develop Connecting Forest planting technique suitable for urban structure and target site conditions on Banpo-daero Street in Seocho-gu.Methods: Through simulation analysis of planting techniques by type (computer climate model: ENVI-met), the street types were classified into the following categories: bare ground type (1), currently planted with <i>Platanus occidentalis</i> (square pruning) (2), a type that can realistically create a strip green (3), and a type that grows the tree canopy and applies <i>Platanus occidentalis</i> and a strip green in the center of the road (4).Results: In the case of creating a 2-meter-wide band green on the existing street trees in the first row, and multi-layered vegetation using the step-by-step arrangement method of small tree + shrub + herbaceous plants, the temperature of up to 0.15°C rise in the roadway area and the temperature of up to 0.12°C went down in the sidewalk area, and PMV (Predicted Mean Vote) was reduced by up to 1.32 in the multi-layer trench planting area. Particulate matter was concentrated, resulting in an increase of about 40~80㎍/㎥in roadways and sidewalks. In the case of the ideal planting arrangement of the route applying the original tree tree tree street + the green belt 2m + the central green zone, the effect of reducing the maximum 1.6°C in the roadway area and 0.3°C in the sidewalk area was shown, and the result of lowering the temperature throughout the target area was derived. arise from street trees, trench planting and trees in Green Area at the Center Line the concentration of particulate matter in the roadway area increased to about 150<i>μ</i>g/㎥, and the concentration of particulate matter in sidewalks and residential areas decreased. Through simulation analysis, we planted street trees with large trunk widths that are favorable for shade formation (<i>Platanus occidentalis</i>) and maintained the unique tree shape, oval, rather than square pruning, and the composition of the strip greenery consisted of multi-layered plantings based on the terraced layout method by introducing tree species with excellent particulate matter reduction capabilities.Conclusion: This study is meaningful in analyzing the function of connecting forests, which play an important role in urban wind ventilation forests, which are created as a solution to improve the urban environment, such as reducing particulate matter in the city and mitigating heat waves, and suggesting planting techniques that can improve their function.

Key Aspects of Implementation of Participatory Budgeting Model in Georgian Municipalities

The article, based on the latest literary sources and factual materials, consistently studies such an important issue of financial theory and economic practice as the key aspects of implementing participatory budgeting in Georgian municipalities. The factors affecting the effectiveness of the implementation of the participatory budgeting model are discussed: the urban structure of the municipality, the size of the budget of the municipality, and the development of civil society. It is determined that any model of participatory budgeting should adhere to the following principles: model design and implementation procedures should be based on good management principles; The selected procedures should take into account the specific context of a particular municipality, including urban structure, budget size, and population participation; At the planning stage, active actors of the model, interested parties should be identified and their rights and duties defined; The model should fully comply with the legislation of Georgia and the established forms of citizen participation. Based on the international experience and the reality of Georgia, the factors affecting the effectiveness of the implementation of the participatory budgeting model are discussed: the urban structure of the municipality, the size of the municipality’s budget, and the development of civil society. It stands to reason that any participatory budgeting model should have, as a minimum, the following working procedures: population group meetings, information campaigns, development and submission of project proposals, voting, and final decision, and Evaluation of participatory budgeting process and work procedures.

Hierarchical accompanying and inhibiting patterns on the spatial arrangement of taxi local hotspots

ABSTRACT The spatial arrangement of taxi hotspots indicates their inherent distribution relationships, reflecting their spatial organization structure, and has received attention in urban studies. Previous studies have primarily explored large-scale hotspots through visual analysis or simple indices, which typically spans hundreds or even thousands of meters. However, the spatial arrangement patterns of small-scale hotspots representing specific popular pick-up and drop-off locations have been largely overlooked. In this study, we quantitatively examine the spatial arrangement of local hotspots in Wuhan and Beijing, China, using taxi trajectory data. Local hotspots are small-scale hotspots with the highest density near the center. Their optimal radius is adaptively calculated based on the data, which is 90 m × 90 m and 110 m × 110 m in Wuhan and Beijing, respectively. Popular hotspots are typically surrounded by less popular ones, although regions with many popular hotspots inhibit the presence of less popular ones. These configurations are termed as hierarchical accompanying and inhibiting patterns. Finally, inspired by both patterns, a KNN-based model is developed to describe these relationships and successfully reproduce the spatial distribution of less popular hotspots based on the most popular ones. These insights enhance our understanding of local urban structures and support urban planning.

Optimising Urban Spatial Structure: The Role of Settlement Systems, Socio-Economics, and Movement Actors in Palopo City, Indonesia

Optimising Urban Spatial Structure: The Role of Settlement Systems, Socio-Economics, and Movement Actors in Palopo City, Indonesia

Examining the Subjective Reasons Leading to Disparities in Academic Achievement among Students in the Architectural Design course at the University of Tripoli.

Architectural education plays a vital role in developing and advancing the urban structure and raising the level of performance of technical departments to achieve a better standard of living for the country’s people within international standards. Architectural design is considered one of the most important basic subjects in the crystallization and formation of an architect's personality. Therefore, the disparity and sometimes weakness of the scientific achievement of students in the Department of Architecture in this subject undoubtedly leads to the inability of graduates to contribute to the process of construction effectively in practical life. This research aims to find out the reasons for the disparity in educational achievement among students of the architectural design subject in the Department of Architecture and Urban Planning at the University of Tripoli. The Descriptive Analytical method was employed to identify key challenges hindering students' educational progress in architectural design courses AR 302 and AR 403. The study examined a sample that comprised over 25% of the students across the two courses. The results were that all reasons for lack of achievement related to the students themselves. They were represented in order and according to importance in the degree of intelligence; hobbies; method of reading; access to books and references and the extent of benefiting from them; and attention and concentration during lectures. The study found that students did not have the moral courage to answer questions due to shyness (91.7%) and fear of the professor (8.3%). The research resulted in a set of recommendations, the most important of which is that professors should invest in the first meeting with students when presenting the course program. The study also recommends professors provide students with advice and guidance in developing their IQ, aim to reduce or eradicate the effects of shyness, and encourage and motivate students to participate in discussions and ask questions. Implementation of these recommendations will increase the likelihood of fostering an integrated educational institution that is constructive and capable of graduating confident scientific cadres.

Spatiotemporal impacts of urban structure and socioeconomic factors on carbon dioxide emissions

Spatiotemporal impacts of urban structure and socioeconomic factors on carbon dioxide emissions

Re-examining Wage Disparities Across Segments of the Indian Labor Market

This article examines income disparities by considering both employer and employee perspectives of informality to scrutinize labor market segmentation in India. Additionally, the research investigates the impacts of varying degrees of urbanization, migration patterns, and industrial structures on formal and informal employment in the labor force. Utilizing data from the National Sample Survey Employment and Unemployment Survey rounds, specifically the 2004–2005 (61st) and 2011–2012 (68th) rounds, along with the Periodic Labour Force Survey 2018–2019 round, quantile regression models and the Recentred Influence Function decomposition method were employed to analyze wage inequality. A selection-corrected wage equation and its estimate were also presented by applying Bourguignon, Fournier, and Gurgand’s model-based selection correction. The study’s findings indicate that by 2019, the labor market had divided into two groups: organized formal workers and others. Further, the study reports wage convergence at lower quantiles and a widening gap at higher quantiles between organized formal and unorganized informal workers. Organized formal workers witness rising earnings, indicating positive wage growth, yet their share in overall employment remains small, which is significant given low job creation and high educated unemployment. At higher wage quantiles, there is a premium for being an informal worker in the organized sector compared to the unorganized sector, indicating a queue for formal employment opportunities in the organized sector. Despite the service sector’s significant role in Indian growth, it lags in creating formal job opportunities, unlike the manufacturing and construction sectors, which emphasize their substantial contribution to formal job generation. This study underlines that categorizing a firm as merely organized or a worker as formally employed is insufficient. Upgrades in these classifications should be accompanied by premiums, with wages being a key consideration. JEL Classification J31, J42, J62, J71

Re-mapping Zagreb‘s Urban Space

Areas with a higher concentration of queer population are a well-established feature of the spatial structure in major cities across the Global North. However, there is a conspicuous lack of research on queer population within post-socialist cities. This paper addresses this gap by exploring the possibility of a higher concentration of queer men population in the Croatia’s capital, Zagreb. Based on the analysis of various spatial datasets, we assumed the existence of a queer men’s residential core in Zagreb, described its position within the city’s spatial structure, and examined the spatial dynamics of its development. Our findings reveal that the urban geography of Zagreb is less heterosexual than is usually perceived. Additionally, we demonstrate how the global patterns of the queer community spatialization have adapted within the post-socialist context with all its local specificities that enabled the unique integration of queer man spaces into Zagreb’s post-socialist urban structure.