Hasil untuk "City planning"

Kanchane Gunawardena, M. Wells, Tristan Kershaw

It has long been recognised that cities exhibit their own microclimate and are typically warmer than the surrounding rural areas. This 'mesoscale' influence is known as the urban heat island (UHI) effect and results largely from modification of surface properties leading to greater absorption of solar radiation, reduced convective cooling and lower water evaporation rates. Cities typically contain less vegetation and bodies of water than rural areas, and existing green and bluespace is often under threat from increasing population densities. This paper presents a meta-analysis of the key ways in which green and bluespace affect both urban canopy- and boundary-layer temperatures, examined from the perspectives of city-planning, urban climatology and climate science. The analysis suggests that the evapotranspiration-based cooling influence of both green and bluespace is primarily relevant for urban canopy-layer conditions, and that tree-dominated greenspace offers the greatest heat stress relief when it is most needed. However, the magnitude and transport of cooling experienced depends on size, spread, and geometry of greenspaces, with some solitary large parks found to offer minimal boundary-layer cooling. Contribution to cooling at the scale of the urban boundary-layer climate is attributed mainly to greenspace increasing surface roughness and thereby improving convection efficiency rather than evaporation. Although bluespace cooling and transport during the day can be substantial, nocturnal warming is highlighted as likely when conditions are most oppressive. However, when both features are employed together they can offer many synergistic ecosystem benefits including cooling. The ways in which green and bluespace infrastructure is applied in future urban growth strategies, particularly in countries expected to experience rapid urbanisation, warrants greater consideration in urban planning policy to mitigate the adverse effects of the UHI and enhance climate resilience.

S. Bibri, J. Krogstie

Yu Zheng, L. Capra, O. Wolfson et al.

M. Batty

J. Jacobs

R. Sutton, Doina Precup, Satinder Singh

D. Shepard

P. Bolund, Sven Hunhammar

M. Antrop

M. Southworth

A. Scott

V. Watson

Urban planning in many parts of the world reflects an increasing gap between current approaches and growing problems of poverty, inequality, informality, rapid urbanisation and spatial fragmentation, particularly (but not only) in cities of the global South. Given past dominance of the global North in shaping planning theory and practice, this article argues that a perspective from the global South can be useful in unsettling taken-for-granted assumptions about how planning addresses these issues. The article takes a first step in this direction by proposing a ‘clash of rationalities’, between techno-managerial and marketised systems of government administration, service provision and planning (in those parts of the world where these apply) and increasingly marginalised urban populations surviving largely under conditions of informality. It draws together theoretical resources beyond the boundaries of conventional planning theory to understand the nature of this conflict, and the nature of the ‘interface’ between those involved, where unpredictable encounter and contestation also open the possibility for exploring alternative approaches to planning.

R. Madlener, Y. Sunak

K. Liao

River cities require a management approach based on resilience to floods rather than on resistance. Resisting floods by means of levees, dams, and channelization neglects inherent uncertainties arising from human-nature couplings and fails to address the extreme events that are expected to increase with climate change, and is thereby not a reliable approach to long-term flood safety. By applying resilience theory to address system persistence through changes, I develop a theory on "urban resilience to floods" as an alternative framework for urban flood hazard management. Urban resilience to floods is defined as a city's capacity to tolerate flooding and to reorganize should physical damage and socioeconomic disruption occur, so as to prevent deaths and injuries and maintain current socioeconomic identity. It derives from living with periodic floods as learning opportunities to prepare the city for extreme ones. The theory of urban resilience to floods challenges the conventional wisdom that cities cannot live without flood control, which in effect erodes resilience. To operationalize the theory for planning practice, a surrogate measure—the percent floodable area—is developed for assessing urban resilience to floods. To enable natural floodplain functions to build urban resilience to floods, flood adaptation is advocated in order to replace flood control for mitigating flood hazards.

Ramil R. Zagidullin, Ivan A. Bannikov

A traffic accident is a phenomenon that has already become an integral part of human life, and although it is often taken for granted, accidents have serious consequences for people, resulting in physical injury, emotional stress, financial loss, and death. In addition, accidents can cause traffic jams, which leads to delays, creating inconveniences for movement. Therefore, the fight against road accidents is an important task around the world. This requires effective measures to prevent and reduce the risk of accidents. First of all, proper planning of the road network contributes to safety, and in order to assess them, it is necessary to substantiate the effectiveness of the proposed measures. One of the methods of substantiating the possibilities of optimizing intersections is computer simulation, which allows not only analyzing, but also predicting the behavior of transport processes. The purpose of the study is to develop practical tools for improving road safety. Methodology. Theoretical and practical research methods were used: system analysis, information synthesis, observations, measurements, experiments and comparisons. Results. The possibilities of practical tools in the formation and development of transport infrastructure are presented. Scenarios for solving the problem of road safety at one of the intersections of the Kazan city road network have been developed. Practical implications. When optimizing intersections, when assessing the risks of deterioration in case of incorrect design, or when evaluating effectiveness, use computer modeling methods. EDN: UKYLKH

Yongsheng Liu, Neng Wang, Tao Kuang et al.

As a core component of the lock filling and emptying system, the operational performance of the valve significantly influences the efficiency and safety of navigation locks. To elucidate the mechanical mechanisms during valve operation, this study investigates the valve structure of the Hongjiang hub under high head conditions. A combined approach of numerical simulation and scale experiment was employed to examine both the mechanical response and hydrodynamic behaviors of the valve. (1) Numerical results indicate the stress concentration is easy to occur in the center of the bottom panel of the valve, which causes the structural displacement. Structural checks confirm that both stress and displacement remain within the allowable design limits, demonstrating the structural adequacy of the valve. The valve’s natural frequency is substantially higher than the dominant energy range of flow-induced excitations, suggesting a low likelihood of severe vibration. (2) Experimental investigations were conducted to evaluate the valve’s hydrodynamic characteristics. Pressure fluctuations on the valve surface were found to be strongly correlated with the valve opening. At small openings, the valve body lies within a high-velocity jet zone formed by the gap between the valve and the sill, resulting in pronounced pressure fluctuations. As the opening increases, the valve body shifts into the valve chamber, and measured pressures become more stable, with reduced fluctuation amplitudes. (3) During the opening process, the opening force initially increases and then decreases, with a peak value of approximately 200 kN. In contrast, the closing force during valve closure follows a “decrease–increase–decrease” trend, reaching a minimum of around −150 kN. (4) Un-der emergency closure conditions at an opening ratio of n = 0.3, the hydrodynamic load coefficient peaks at approximately 1.22. The effect of the valve opening speed on the dynamic load is found to be negligible. The findings provide theoretical insights and practical guidance for the design and manufacture of lock valves operating under high head conditions.

Delores Springs

This article explores how smart leadership contributes to developing inclusive, equitable, and sustainable smart cities amidst the backdrop of rapid urbanization and technological advancement. Smart leadership, as articulated in this article, embodies a holistic and forward-looking approach that prioritizes the well-being and inclusion of residents as a primary concern. In line with this approach, technological innovation is harmoniously embodied alongside an unwavering commitment to social justice, sustainability, and long-term planning, enabling cities that are not only technologically advanced, but also more sustainable, equitable and enriched for all residents. Central to this visionary leadership is a profound recognition of equality and representation in city governance. The principles of inclusive leadership require a leadership structure that reflects the diversity of the population, ensuring that the voices of all communities are integral to decision-making processes. Smart leaders actively advocate for the problems and aspirations of each segment of society, promoting a sense of belonging and empowerment among residents, thereby strengthening the city’s commitment to the principles of social cohesion and equal opportunities. In addition, sound leadership recognizes the key challenge of the digital divide, which can exacerbate disparities in urban landscapes. This article highlights the fundamental importance of digital access in ensuring all residents’ full participation in modern society, economics, and governance. Smart leaders introduce policies and initiatives to bridge the digital divide and ensure equal access to digital tools and information for every resident, regardless of socioeconomic background. This proactive approach promotes digital inclusion and lays the foundation for seamless smart technology integration in the city, ultimately improving its residents’ overall quality of life. Through a systematic analysis of articles, this inquiry observes the metamorphosis of cities into centers of advanced technological implementation and economic dynamism. The article proposes the author’s Smart City Leadership Activity Model, which contains several key principles of smart leadership in the context of equitable, sensible, and strategic smart city growth, development, and innovation.

C. Wamsler, Ebba Brink, C. Rivera

Barre Douglas E., Mizier-Barre Kazimiera A., Griscti Odette et al.

Objective. The intent of the present study was to test two hypotheses. The primary hypothesis was that there would be differences between blood serum individual free fatty acids (SIFFA) and serum individual total fatty acids (SITFA) in terms of their different relationships (correlations) to each of homeostatic model assessment-individual insulin resistance (HOMA-IR) and homeostatic model assessment-individual insulin resistance-percentage β-cell function (HOMA-% β) remaining in human type 2 diabetic patients with pre-flaxseed oil (FXO) and pre-safflower oil (SFO) administration. The secondary hypothesis was that FXO (rich in alpha-linolenic acid, ALA) supplementation would alter these correlations differently in the SIFFA and STIFFA pools in comparison with the placebo SFO (poor in ALA).

Tan Yigitcanlar, Suharto Teriman