Urban Density Research Articles

Legal Perspectives on New Urban Quarters in Germany: Living the Dream of the Compact City?

The ‘leitmotif’ of the compact city has become a widely embraced template for sustainable urban development. Particularly infill and redevelopment areas, as well as many planned new settlements, have been built following the planning principles of urban compaction. Numerous positive effects are attributed to high-density settlements such as more efficient use of infrastructure and less reliance on automobile travel. Planning law and policies, in Germany as well as other countries around the world, regularly strive to advance high-density developments, but it is by no means clear whether the prescribed densities in planning policies actually lead to vibrant and healthy places which fulfill the expectations of their inhabitants with regards to their quality of life. The study aims to analyze the relation between binding land-use plans in Germany and individual perceptions of urban density through a case study-based survey. This paper contributes to providing new information on achieving compact urban form and quality of life in new urban quarters by analyzing the change of densities over the past three decades in ‘large’ urban developments across Germany, by an in-depth assessment of planned and built densities within an archetypal urban extension and finally by contrasting these ‘objective’ figures and findings with the ‘subjective’ feelings of inhabitants. For sources of information, this paper draws from literature, surveys and empirical analyses as well as desktop-studies.

Assessment of low impact development (LID) strategies under different land uses in an urban sub-catchment in the Philippines

Lack of studies in developing countries with tropical climate such as the Philippines limit local LID adoption. This study compared the performance of different LID scenarios across different urban land use types at the sub-catchment level using peak flow, runoff volume and flood reductions as performance criteria. Results showed that the most effective strategies for each land use are: 1) combined green roof and bioretention for low-density residential (reduction up to 10% peak flow, 11% runoff volume and 33% flood volume); 2) green roof for high-density residential (8% peak flow, 6% runoff volume and 18% flood volume); 3) combined rain barrel, bioretention and permeable pavement for industrial (23% peak flow, 41% runoff volume and 56% flood volume), and 4) combined vegetative swale and detention pond for urban open spaces (81% peak flow, 8% runoff volume and 84% flood volume). While effective for most low intensity storms, the observed sharp decrease in LID performance with increased rainfall intensity poses a major challenge, especially in the context of the Philippines frequented by high intensity storms. This study also examined how differences in land use characteristics influence LID performance, unlike most studies that focused on LID type comparisons. It showed that low urban density setting positively affected peak flow and flood reduction performance of rain barrels and green roofs, while good drainage infrastructure quality positively affected peak flow and flood reduction performance of rain barrels and bioretention. Decision-makers may use these findings to conduct rapid assessments on LID selection and siting, provided similarities between land use characteristics described in this study and those at their localities are justified. This can lead to increased LID adoption towards building water resilient, and sustainable cities.

How is urban agriculture practiced, institutionalized, implemented, and sustained? A literature review

Urban agriculture (UA) has emerged as a crucial strategy for ensuring sustainable food access in both developing and developed nations. However, the interplay between planning regulations and land availability significantly influences farmed land's scope and location, directly impacting UA activities' scale and intensity. The spatial mechanisms governing land use for UA stem from planning regulations, which may or may not align with food policies shaped by municipal actors—whose objectives often differ from those of civil actors. This review analyzes current urban agriculture practices in cities to explore how UA is practiced, institutionalized, implemented, and sustained, considering the influence of governance mechanisms and focusing on land-based forms of UA. By reviewing 51 peer-reviewed articles, consistent challenges impeding UA across various contexts were identified. Key factors include discord between civil and municipal actors, contextual elements affecting the enactment of supportive UA policies, and urban densification encroaching upon UA land. While these issues vary between developed and developing cities, they are primary drivers of informal or constrained UA practices and tenure insecurity. The review concludes that policies aimed at regulating UA to enhance food security should prioritize scaling up farming practices by ensuring access to larger plots with more secure tenure durations. Additionally, it emphasizes the need for flexible land-use and zoning ordinances that accommodate dual land uses, the establishment of UA protection zones to counter urban densification, and the active participation of civil actors in the process.

Effects of Nesting Material and Housing Parameters on Feed Wastage Behavior in Female Swiss Webster Mice.

Feed wastage in laboratory mice, also known as chewing or grinding behavior, is problematic for program management and animal welfare. The destruction of pelleted feed without consumption produces a powder accumulation on the cage floor called orts. Ort accumulation disrupts the cage microenvironment and can clog Lixits resulting in flooding. Moreover, added labor adds cost, and cage disruption increases animal stress. Published studies examining the behavior and ways to mitigate it have had inconsistent results, and the cause or causes have not yet been fully identified. The purpose of this study was to identify methods to reduce the development of chewing behavior in laboratory mice. Female Swiss Webster (Tac:SW) mice (n = 144) were randomly assigned to one of 8 groups (12 cages per group) with 2 housing densities (single and pair) and 4 nesting material paradigms. Mice were housed on clean bedding for 8 wk and then soiled bedding for the next 8 wk. Chewing behavior was evaluated by feed weight, cage weight, and feed scores. The addition of a Diamond Twist significantly increased ort production, while nest transfer decreased it but not significantly. Pair housing increased overall orts but not when adjusted for animal number. These results identified potential contributing factors to chewing behavior. However, further research is needed to elucidate the exact causes and solutions.

Enhancing Urban Livability with Vertical Gardens in Mexico City Strategies for Sustainable Urban Development

This thesis explores the implementation of vertical gardens in Mexico City as a strategic approach to enhance urban livability and promote sustainable development. Faced with environmental challenges such as severe air pollution and the urban heat island effect, coupled with limited availability of green space due to high urban density, Mexico City requires innovative solutions to improve its urban ecosystem. This research examines the role of vertical gardens in addressing these challenges by purifying air, reducing temperatures, and supporting urban biodiversity. Additionally, it investigates the socio-economic and psychological impacts of increased greenery on the community. The study draws on case studies from cities with similar challenges and proposes tailored implementation strategies for Mexico City, assessing the potential benefits and impacts of vertical gardens on property values, community well-being, and public health. This thesis contributes to the field by providing a comprehensive framework for integrating vertical gardens into urban landscapes, potentially transforming them into more sustainable and livable environments.

Compulsory acquisition of property for urban densification in South Africa: an answer to the chronic housing backlog?

ABSTRACT The cities are rapidly sprawling in South Africa, despite the city authorities’ attempts at containing the sprawl. This has signalled the need for strong urban densification policy which – if properly designed and implemented – promises to yield several benefits such as smart, inclusive, equitable and sustainable cities. Densification policy can also facilitate access to adequate housing which remains a challenge in South Africa where millions of people are inadequately housed, if not homeless. Using a qualitative investigation and literature review to analyse the relevant policies and case law, this article investigates whether a legally sound argument can be developed for compulsory acquisition of property to be deployed as a mechanism to facilitate enhanced access to housing for the poor and marginalised. Put differently, the article asks whether compulsory acquisition could be an ideal method of facilitating densification to ramp up housing provision across the country. The findings suggest that urban densification policy is a necessary intervention in that regard. Compulsory acquisition of property is advanced as an optimal method to achieve this endeavour.

Environmental implications of migration: Worldwide insights

This study investigates the impact of migrants’ skills, employment sectors, urban planning and energy sectors efficiency on carbon emissions. Utilizing the static and dynamic methods Dynamic GMM, Spatial methods on a panel dataset covering 156 nations from 2000 to 2022. Our findings reveal that heightened geopolitical risk leads to both short and long run increases in carbon emissions and the ecological footprint. The results indicate positive impact of international migration, travel services and urbanization on CO2 emissions. The results also investigate interaction effects, revealing the amplifying effect of urban population density on the association between international migration and CO2 emissions. The disaggregated analysis shows that migrants positively impact CO2 emissions in high income, Lower Income while there is complex association in upper middle-income economies. The findings provide policymakers with valuable insights for prioritizing the adoption of renewable energy, sustainable urban planning, energy efficiency measures, sustainable tourism practices, carbon pricing mechanisms, international cooperation, and sustainable economic growth strategies that are tailored to specific country contexts.

How did the diversity of woody plants in urban forests vary with the urban-rural gradient in Qingdao, China?

The distribution and diversity of woody vegetation are crucial for understanding the structure and ecology of urban forests. As urbanization accelerates, the construction and composition of urban forests vary significantly along the urban-rural gradient. Qingdao's urban forests offer an opportunity to test the relationship between the diversity of woody plants and the urban-rural gradient. We classified the urban-rural gradient using imperviousness and construction time, then investigated the diversity of woody plants in Qingdao's urban forests under different urban-rural gradients and tested the reasonableness of their allocation. Correlation analysis found that the diversity index of woody plants in urban forests was highly connected to the urban-rural gradient (by imperviousness: rMargalef Index = −0.589, rShannon-Wiener Index = -0.373, rPielouIndex = −0.170, rSimpson Index = 0.272/by construction time: rMargalef Index = −0.530, rShannon-Wiener Index = −0.360, rPielouIndex = −0.148, rSimpson Index = 0.272/0.174). With a decrease in urbanization density, the Margalef (H), Shannon-Wiener (H′), and Simpson (D) indices all decreased while the Pielou (E) index increased. The four diversity indices showed a substantial correlation with one another, but not with the Margalef and Pielou indices. The analysis utilizing the 10/20/30 rule of empirical demonstrates a clear irrationality in allocating shrub species in Qingdao's urban forests, and the distribution of tree species is reasonable. Based on the study results, strategies for optimizing and enhancing urban forests in Qingdao are proposed for different urban-rural gradients, respectively. This study can provide a scientific framework for urban biodiversity conservation and management in Qingdao and serve as a guide for urban forests and greening with comparable climates.

A GIS-Based Analysis of the Public Open Space Distribution and Accessibility in Gurugram City, India

The rapid pace of urbanization and increasing urban density in India has led to critical concern about the sustainability and livability of urban environments. In the city of Gurugram, public open spaces (POS) like parks and playgrounds are limited, highlighting the problem regarding their availability and accessibility. This study analyzes the current distribution of POS in the city of Gurugram at the ward level and compares the existing situation with national planning guidelines. It also aims to identify the population served by POS and the areas deficit in POS provision. The analysis reveals a deficit in per-capita POS at the city level, which stands at 3.14 m2 and shows high variability across different wards. A significant gap in the provision of housing area and neighborhood level POS was observed. The accessibility index calculated using Geographic Information System (GIS) based network analysis, reveals uneven access patterns across the city, with five wards lacking POS accessibility for residents, located primarily in central and southern-central areas. None of the wards of the city had all of its area serviced by POS, and only six wards had above 50 percent of the population residing in area serviced. These findings emphasize the need for strategic interventions to ensure universal access to POS, aligning with the sustainable development goals for urban areas.

Land use land cover change in the African Great Lakes Region: a spatial–temporal analysis and future predictions

The African Great Lakes Region has experienced substantial land use land cover change (LULCC) over the last decades, driven by a complex interplay of various factors. However, a comprehensive analysis exploring the relationships between LULCC, and its explanatory variables remains unexplored. This study focused on the Lake Kivu catchment in Rwanda, analysing LULCC from 1990 to 2020, identifying major variables, and predicting future LULC scenarios under different development trajectories. Image classification was conducted in Google Earth Engine using random forest classifier, by incorporating seasonal composites Landsat images, spectral indices, and topographic features, to enhance discrimination and capture seasonal variations. The results demonstrated an overall accuracy exceeding 83%. Historical analysis revealed significant changes, including forest loss (26.6 to 18.7%) and agricultural land expansion (27.7 to 43%) in the 1990–2000 decade, attributed to political conflicts and population movements. Forest recovery (24.8% by 2020) was observed in subsequent decades, driven by Rwanda’s sustainable development initiatives. A Multi-Layer Perceptron neural network from Land Change Modeler predicted distinct 2030 and 2050 LULC scenarios based on natural, socio-economic variables, and historical transitions. Analysis of explanatory variables highlighted the significant role of proximity to urban centers, population density, and terrain in LULCC. Predictions indicate distinct trajectories influenced by demographic and socio-economic trends. The study recommends adopting the Green Growth Economy scenario aligned with ongoing conservation measures. The findings contribute to identifying opportunities for land restoration and conservation efforts, promoting the preservation of Lake Kivu catchment’s ecological integrity, in alignment with national and global goals.Graphical

DEMOGRAPHIC DYNAMICS AND URBAN PROPERTY CRIME: A LINEAR REGRESSION ANALYSIS IN KUALA LUMPUR AND PUTRAJAYA (2015-2020)

In an era where urbanization is rapidly transforming the landscape of cities, this study provides a crucial overview of how demographic shifts influence property crime in metropolitan areas. The paper delves into the complex interplay between property crime rates and demographic characteristics in the urban settings of Kuala Lumpur and Putrajaya, Malaysia, over six years from 2015 to 2020. Employing linear regression analysis, the study meticulously examines the relationship between property crime and various demographic factors, including total population, male and female populations, and residential and household densities. The findings indicate a consistent positive correlation between total population and property crime, emphasizing urban density's role in crime propensity. Notably, the male population shows a stronger correlation with property crime than females. The study also highlights how residential and household densities influence property crime in these urban settings. These insights are invaluable for policymakers and urban planners, guiding targeted strategies to reduce property crime in growing cities.

A multi-sectional analysis of building height, layout, and urban density on seasonal energy consumption: A case study

This study aims to investigate the influence of building height and layout on energy consumption. It also analyzes methods for reducing energy consumption in these buildings. The EnergyPlus software performs simulations under local climatic conditions for all seasons. The city is divided into several sections based on cardinal directions, and energy consumption is calculated for each section, considering the city's distinct seasonal variations. Buildings in suburban areas with more sunlight exhibited higher overall energy consumption due to the reliance on heating and cooling systems, compared to the city center where denser urban areas moderated temperature extremes. Additionally, building design and insulation played significant roles. The analysis also revealed a west-to-east trend; higher consumption at the edges compared to the center. This is attributed to factors such as building density and shade from taller structures. The study further examined the impact of varying building heights. While most buildings were 20 meters tall, specific rows ranged from 21 to 25 meters. Changing these heights resulted in decreased cooling and increased heating demands in the north-south analysis, and reduced demands for both heating and cooling in the west-east analysis. This highlights the complex interplay between building layout, height, and energy consumption.

Exploring the paradox of densification and greening in China’ s old cities

Urban densification is widely regarded as a key strategy for curbing urban sprawl and optimizing resource efficiency. However, it still threatens urban greenspaces by altering the original land use. The imperative to preserve and restore urban greenspaces has gained increased attention, aligning with the global spotlight on urban resilience. This prompts the crucial question: How will urban densification impact urban greening? Focusing on the old city areas of 159 cities with over one million population in China, we depicted the dynamics of urban greenness using remote sensing data and explored greening trends under urban densification on both horizontal and vertical scales by generalized additive model (GAM). The findings are as follows: (1) As urban horizontal density increased from 68.4 % to 93.1 %, a significant U-shaped trend in urban greenness emerged within the old city areas over the past three decades. Notably, 80 % of these cities experienced turning points before 2010. (2) Almost half of the cities have recovered the urban greenness to 30 years ago, with a growth of 6.58 % on average. While urban densification led to a loss of greenness (-0.0197±0.0182), urban greenspaces countered this with a gain of 0.0049±0.0075, and the original built-up area contributed a gain of 0.0027±0.0284. (3) We decomposed urban densification into horizontal and vertical growth. The horizontal growth coincides with the greenness loss initially, but the rebound occurs when the horizontal density approaches 83 %. Vertical growth, on the other hand, is negatively correlated with urban greenness. Our study depicts the turning point of urban greening in old city areas unveiling the ecological effect of urban densification, which provides a reference for the sustainable development of future urbanization.

Assessing urbanization dynamics using a pixel-based nighttime light indicator

Nighttime light (NTL) is a reliable indicator for measuring urban development, population density, and economic activities. This study sets out to explain the spatio-temporal pattern of urbanization and population distribution using pixel-based NTL data. Changes in NTL intensity in Puglia (Italy) were evaluated from 2014 to 2023, and how NTL is affected by various spatial metrics was investigated. Summer–winter differences at the pixel level were monitored utilizing the Normalized Nighttime Light Index (NNLI), and the relationship between this indicator and tourism was assessed. A consistent increase in NTL across the region in both summer and winter was measured, with variations among provinces. Urban areas with high population density showed greater NTL values, while inland areas showed low NTL intensity. The study also revealed that proximity to urban areas was the most influential factor in predicting NTL intensity. The analysis revealed that differences between summer and winter correlated with tourist activity, especially in coastal municipalities. Leveraging NTL images can support decision-making across various sectors and aid in developing evidence-based urban strategies tailored to local needs and challenges.

Impact of different housing densities combined with Environmental enrichment on the production of Japanese quail

This study evaluated the zootechnical performance, egg quality, and behavior of Japanese quails in the laying phase housed in cages of different densities and with or without environmental enrichment. A total of 224 quail were used and distributed into two groups: one with a housing density of 122.7 cm2 bird-1 and one with a housing density of 157.8 cm2 bird-1, each with and without environmental enrichment. The results showed that environmental enrichment did not influence the zootechnical performance parameters of the quail. However, housing density independently affected performance, except for egg mass and bird viability. A lower density (157.8 cm2 bird-1) resulted in greater specific egg weight, albumen percentage, and shell thickness. The interaction between density and environmental enrichment revealed that eggs from quail housed at higher density without enrichment had a greater yolk percentage, while quails housed at lower density without enrichment had a greater shell percentage. The tonic immobility time of the quails was not affected by treatment with different densities or environmental enrichment agents. It can be concluded that a lower housing density, with seven quail per cage (157.8 cm2 bird-1), regardless of environmental enrichment, provides better zootechnical performance and egg quality.

Everyday urbanism in Beijing’s edge cities: on spatial and experience patterns

ABSTRACT The concentration of people in mega agglomerations in China has been challenging urban governance to reduce daily commuting by planning and investing in new edge cities. The main objective of this paper is to investigate everyday urbanism in two recently developed edge cities in Beijing by considering spatial conditions as well as resulting activity and experience patterns. The applied mapping surveys include land use distributions and density calculations via evaluating GIS data as well as field observations to investigate the typical experiences of 32 representative neighborhood walks. One of the main findings is the overall dependency of neighborhoods on rigid grid planning defining urbanism with large block sizes, resulting in walking experiences with a majority being dominated by compound walls along main roads and only 15% of walks being experienced along active frontages despite rather high urban densities with up to 300 residents per hectare.

Use of LCZs with urban canopy modeling to evaluate urban growth effects on meteorological conditions in the Salt Lake Valley

Urban Canopy Models (UCMs) can be used to represent urban characteristics on a mesoscale without accounting for effects of individual buildings. A WRF-based single-layer urban canopy model (SLUCM) was validated for the greater Salt Lake City area (GSLA) using measurements from two weather stations for a one-week period during summer 2019. A baseline model based on current GSLA properties developed using the Noah land surface model, SLUCM, and refined urban classifications based on WUDAPT Local Climate Zones (LCZs) produced acceptable predictions and computational times. The baseline model was validated using measured meteorological data and clearly showed diurnal heating patterns. Three scenarios representing multi-decade growth were defined by modifying LCZs in different parts of the GSLA. Compared to baseline values, results showed increased urban density increased local nighttime temperatures 5–10 °C depending on the extent of growth, but did not affect daytime temperatures. This was due to changes in LCZ anthropogenic heating rates and sky view factors which were most noticeable during early nighttime hours, consistent with atmospheric heat island behavior. Predicted 2-m relative humidity and 10-m wind speeds changed minimally.

Impacts of solid waste management strategies in urban high density suburbs: a case of Amaveni suburb, Kwekwe, Zimbabwe

Improper solid waste management is one of the causes of environmental and health problems in many cities worldwide. It is in this context that the study aimed to determine the solid waste management strategies used in Amaveni suburbs in Kwekwe, Zimbabwe and assess the health and environmental problems associated with the solid waste management strategies used in Amaveni. Researchers used a mixed method design in which quantitative and qualitative data was collected at the same time. Semi –structured interviews, field observations and questionnaires were used to collect data. The sample comprised 380 Amaveni residents, 3 Kwekwe City employees and one Environmental Management Agency (EMA) official. Qualitative data was analyzed thematically while quantitative data was analyzed using inferential statistics. Open dumping and open burning were the dominant solid waste management strategies in Amaveni. The main health problems identified were cholera and malaria. Air pollution, water pollution and loss of urban beauty were the main environmental problems identified. From the findings it can be concluded that solid waste management strategies used in Amaveni were associated with many health and environmental problems and as a result sustainable solid waste management was proposed.

Analyzing Thermal Environment Contributions and Driving Factors of LST Heterogeneity in Different Urban Development Zones

Analyzing the impacts of urban landscape patterns on the thermal environment has become one of the key research areas in addressing urban heat islands (UHIs) and improving the living environment. A case study was carried out in Fuzhou, Fujian Province of China, and bi-temporal Landsat imagery was selected to calculate land surface temperature (LST), percent impervious surface area (ISA), and fractional vegetation cover (FVC). The urban area was further divided into three concentric urban zones, ranging from the city center to the urban periphery, based on urban development densities. The spatial pattern of LST and its variance were analyzed and compared between different zones and different dates. The thermal environment contribution of different zones was also quantified to indicate the change in urban landscape patterns resulting from urban expansion in different zones. Furthermore, Geodetector was used to explore the single factors and interaction factors controlling the spatial patterns of LST in each zone. The results showed that (i) urban expansion primarily increased in Zone 2 and Zone 3, and the areal proportion of high and sub-high LST areas increased from 56.11% and 21.08% to 62.03% and 32.49% in Zone 2 and Zone 3, respectively, from 2004 to 2021; (ii) the heat effect contribution of Zones 2 and 3 reached from 75.16% in 2004 to 89.40% in 2021, indicating that the increase in ISA with >LSTmean was more pronounced in Zone 3 and Zone 2 during the period; (iii) the driving factors of LST spatial distribution were regionally different because of the different landscape patterns, and the explanatory power for the heterogeneity of LST in Zone 1 was weaker than in Zone 2 and Zone 3 in the study area; (iv) the interaction of different factors had a higher explanatory power in the spatial distribution of LST than a single factor in each zone because the distributions of land cover types are heterogeneous in urban areas. The results of this study can be used to improve urban planning for urban ecology and UHI mitigation.

Identifying the Drivers Related to Animal Reservoirs, Environment, and Socio-Demography of Human Leptospirosis in Different Community Types of Southern Chile: An Application of Machine Learning Algorithm in One Health Perspective.

Leptospirosis is a zoonosis with global public health impact, particularly in poor socio-economic settings in tropical regions. Transmitted through urine-contaminated water or soil from rodents, dogs, and livestock, leptospirosis causes over a million clinical cases annually. Risk factors include outdoor activities, livestock production, and substandard housing that foster high densities of animal reservoirs. This One Health study in southern Chile examined Leptospira serological evidence of exposure in people from urban slums, semi-rural settings, and farm settings, using the Extreme Gradient Boosting algorithm to identify key influencing factors. In urban slums, age, shrub terrain, distance to Leptospira-positive households, and neighborhood housing density were contributing factors. Human exposure in semi-rural communities was linked to environmental factors (trees, shrubs, and lower vegetation terrain) and animal variables (Leptospira-positive dogs and rodents and proximity to Leptospira-positive households). On farms, dog counts, animal Leptospira prevalence, and proximity to Leptospira-contaminated water samples were significant drivers. The study underscores that disease dynamics vary across landscapes, with distinct drivers in each community setting. This case study demonstrates how the integration of machine learning with comprehensive cross-sectional epidemiological and geospatial data provides valuable insights into leptospirosis eco-epidemiology. These insights are crucial for informing targeted public health strategies and generating hypotheses for future research.