Search results for "Megacity"

Overview: On the transport and transformation of pollutants in the outflow of major population centres - Observational data from the EMeRGe European …

2022

Megacities and other major population centres (MPCs) worldwide are major sources of air pollution, both locally as well as downwind. The overall assessment and prediction of the impact of MPC pollution on tropospheric chemistry are challenging. The present work provides an overview of the highlights of a major new contribution to the understanding of this issue based on the data and analysis of the EMeRGe (Effect of Megacities on the transport and transformation of pollutants on the Regional to Global scales) international project. EMeRGe focuses on atmospheric chemistry, dynamics, and transport of local and regional pollution originating in MPCs. Airborne measurements, taking advantage of …

2014

Abstract. For the investigation of megacity emission plume characteristics mobile aerosol and trace gas measurements were carried out in the greater Paris region in July 2009 and January–February 2010 within the EU FP7 MEGAPOLI project (Megacities: Emissions, urban, regional and Global Atmospheric POLlution and climate effects, and Integrated tools for assessment and mitigation). The deployed instruments measured physical and chemical properties of sub-micron aerosol particles, gas phase constituents of relevance for urban air pollution studies and meteorological parameters. The emission plume was identified based on fresh pollutant (e.g., particle-bound polycyclic aromatic hydrocarbons, bl…

Societal premises for sustainable development in large southern cities

2005

Abstract This article examines considerations related to the societal premises of a ‘sustainable city’ in the context of large southern cities. The article also reviews some alternative concepts to ‘sustainable city’ such as ‘eco-city’ and ‘ecological city’ and examines their suitability in the South. The article proposes that the greatest challenge of environmental urban development in the South is not necessarily the lack of environmental services and infrastructure, but the societal structures reproducing unequal distribution and malfunctioning of these services. The authors’ empirical evidence and personal experience from Lagos, New Delhi, Cairo and Manila is presented to elaborate the …

From COVID-19 to future electrification: Assessing traffic impacts on air quality by a machine-learning model

2021

The large fluctuations in traffic during the COVID-19 pandemic provide an unparalleled opportunity to assess vehicle emission control efficacy. Here we develop a random-forest regression model, based on the large volume of real-time observational data during COVID-19, to predict surface-level NO(2), O(3), and fine particle concentration in the Los Angeles megacity. Our model exhibits high fidelity in reproducing pollutant concentrations in the Los Angeles Basin and identifies major factors controlling each species. During the strictest lockdown period, traffic reduction led to decreases in NO(2) and particulate matter with aerodynamic diameters <2.5 μm by –30.1% and –17.5%, respectively, bu…

Managing Metro Manila

2017

Metro Manila residents are confronted everyday with the challenges of flooding, substandard housing and horrendous traffic. In this low altitude plain, any significant rainfall raises water levels in many small streams, and contributes to traffic jams. The rapid population growth of the metropolis has led to the proliferation of squatter areas, including alongside flood-prone rivers and railroad tracks. The lack of discipline and of decent garbage management contribute in turn to a worsening of floods when streams are covered with litter. The fast rise in motorization rates, coupled with the many imperfections of the public transport system, make Manila one of the most congested cities in t…

Environment in Megacities: Tehran Waterscapes

2021

Defining contemporary urban paradigms is the challenge of this time, especially when the urban dynamics are so fluid they spread uncontrollably in overextended and overpopulated territories. This is the case for megacities, metropolitan areas with more than 10 million inhabitants, which place the emphasis on how to manage energy consumption in such filled places. In this frame, the city of Tehran, the capital of the Islamic Republic of Iran, scene of political and cultural disputes, administrative and economic headquarter of the country, with its nearly 15 million residents and a daily traffic of more than 20 million people, is currently one of the most populous cities in the world and repr…

Corrigendum to "Impact of dust on tropospheric chemistry over polluted regions: a case study of the Beijing megacity" published in Atmos. Chem. Phys.…

2010

Moving around the Philippines

2012

International audience; Visitors to Manila are quickly aware of the traffic jams and impediments to efficient transport within the capital region of the Philippines. Hours seem to be lost in traffic, and public transportation is very crowded. What are the reasons for these difficulties? Poor planning, lack of enforcement of the rules of circulation, an excessive rate of motorization, an insufficient development of quality public transit? What should be the role of "informal" transport (trisikel, pedicab, jeepneys) in a system of mobilities that should remain fair to all, rich and poor alike? The same set of questions arises for the mobility across the country. As an archipelago, and a count…