scholarly journals Graz Lagrangian Model (GRAL) for Pollutants Tracking and Estimating Sources Partial Contributions to Atmospheric Pollution in Highly Urbanized Areas

Atmosphere ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1375
Author(s):  
Aleksey A. Romanov ◽  
Boris A. Gusev ◽  
Egor V. Leonenko ◽  
Anastasia N. Tamarovskaya ◽  
Alexander S. Vasiliev ◽  
...  
Keyword(s):  
Air Quality ◽  
Urban Landscape ◽  
Weather Conditions ◽  
Lagrangian Model ◽  
Emission Sources ◽  
Computational Domain ◽  
Surface Atmospheric Layer ◽  
Wind Speeds ◽  
High Rise ◽  
Heterogeneous Landscape

Computational modeling allows studying the air quality problems in depth and provides the best solution reducing the population risks. This research demonstrates the Graz Lagrangian model effectiveness for assessing emission sources contributions to the air pollution: particles tracking and accumulation estimate. The article describes model setting up parameters and datasets preparation for the analysis. The experiment simulated the dispersion from the main groups of emission sources for real weather conditions during 96 h of December 2018, when significant excess of NO2, CO, SO2, PM10, and benzo(a)pyrene concentrations were observed in the Krasnoyarsk surface atmospheric layer. The computational domain was a parallelepiped of 40 × 30 × 2.5 km, which was located deep inside the Eurasian continent on a heterogeneous landscape exaggerated by high-rise buildings, with various pollutions sources and the ice-free Yenisei River. The results demonstrated an excellent applicability of the Lagrange model for hourly tracking of particle trajectories, taking into account the urban landscape. For values <1 MPC (maximum permissible concentration) of peak pollutants concentrations, the coincidences were 93 cases, and for values < 0.1 shares of MPC, there were 36 cases out of the total number of 97. The same was found for the average daily concentration for values <1 MPC—31, and for values <0.1 MPC—5 matches out of 44. Wind speeds COR—65.3%, wind directions COR—68.6%. The Graz Lagrangian model showed the ability to simulate air quality problems in the Krasnoyarsk greater area conditions.

scholarly journals A Comparative Study on Air Pollution Characteristics in Four Key Cities during 2013 in Guangxi Province, China

2021 ◽  
Vol 13 (4) ◽  
pp. 1612
Author(s):  
Jing-Ying Mao ◽  
Zhi-Ming Chen ◽  
Zong-Kai Jiang ◽  
Zhao-Yu Mo ◽  
Hong-Jiao Li ◽  
...  
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
Weather Conditions ◽  
Ambient Air ◽  
The Other ◽  
Emission Sources ◽  
Ambient Air Quality ◽  
Long Distance ◽  
Local Emission ◽  
Pollution Episodes

Based on ambient air quality data of the four key cities (Nanning, Liuzhou, Guilin, and Beihai) in Guangxi, China, along with an analysis of the main emission sources, topographic features, weather conditions, and backward trajectories, the variation of main air pollutants and pollution episodes in the four cities were studied. Results showed that air pollution was most serious in Liuzhou and Guilin, followed by Nanning and Beihai. PM2.5 was the dominant pollutant in each city, followed by O3, PM10, and NO2. Concentrations of SO2 and CO did not exceed their National Ambient Air Quality Standard Grade II limit values. In the cities, the concentrations of PM2.5, PM10, NO2, and SO2 were high during fall and winter and low during spring and summer, while the concentrations of O3 were high during fall and low during the other seasons. Concentrations of CO were low during summer and high during the other seasons in Nanning and Liuzhou, while they were high during spring and winter and low during summer and fall in Guilin and Beihai. In these cities, pollution episodes resulted mainly from stagnant accumulation and showed characteristics of regional pollution. However, pollution levels and durations for each city were different due to differences in main pollution sources, local geography, and weather conditions. The influences of air masses on the four cities were similar. They were mainly influenced by local emission sources in the spring, while during autumn, long-distance transportation from Hunan and Hubei was significant. In winter, air pollution in Nanning and Beihai was mostly affected by local emission sources, and that in Liuzhou and Guilin was mainly affected by long-distance transportation from the south and northeast of Guangxi.

scholarly journals Assessment of Emission Reduction and Meteorological Change in PM2.5 and Transport Flux in Typical Cities Cluster during 2013–2017

2021 ◽  
Vol 13 (10) ◽  
pp. 5685
Author(s):  
Panbo Guan ◽  
Hanyu Zhang ◽  
Zhida Zhang ◽  
Haoyuan Chen ◽  
Weichao Bai ◽  
...  
Keyword(s):  
Air Quality ◽  
Action Plan ◽  
Influence Factors ◽  
Pollution Prevention ◽  
Weather Conditions ◽  
Yangtze River Delta ◽  
Control Measures ◽  
Joint Control ◽  
Air Quality Model ◽  
Quality Model

Under the Air Pollution Prevention and Control Action Plan (APPCAP) implemented, China has witnessed an air quality change during the past five years, yet the main influence factors remain relatively unexplored. Taking the Beijing-Tianjin-Hebei (BTH) and Yangtze River Delta (YRD) regions as typical cluster cities, the Weather Research Forecasting (WRF) and Comprehensive Air Quality Model with Extension (CAMx) were introduced to demonstrate the meteorological and emission contribution and PM2.5 flux distribution. The results showed that the PM2.5 concentration in BTH and YRD significantly declined with a descend ratio of −39.6% and −28.1%, respectively. For the meteorological contribution, those regions had a similar tendency with unfavorable conditions in 2013–2015 (contribution concentration 1.6–3.8 μg/m3 and 1.1–3.6 μg/m3) and favorable in 2016 (contribution concentration −1.5 μg/m3 and −0.2 μg/m3). Further, the absolute value of the net flux’s intensity was positively correlated with the degree of the favorable/unfavorable weather conditions. When it came to emission intensity, the total net inflow flux increased, and the outflow flux decreased significantly across the border with the emission increasing. In short: the aforementioned results confirmed the effectiveness of the regional joint emission control and provided scientific support for the proposed effective joint control measures.

Retrofit of Aerodynamic Cable Instability on a Cable-Stayed Bridge: Case Study

2000 ◽  
Vol 1740 (1) ◽  
pp. 61-67 ◽  
Author(s):  
Niket M. Telang ◽  
Charles M. Minervino ◽  
Paul G. Norton
Keyword(s):  
Large Amplitude ◽  
Weather Conditions ◽  
Mitigation Measures ◽  
Mobile Bay ◽  
Department Of Transportation ◽  
Light Rain ◽  
Wind Speeds ◽  
Cable Stays ◽  
Large Amplitude Vibrations

Elegantly poised over the Mobile River, the twin pylons and the semi-harped cable stays of the Cochrane Bridge subtly complement the vast and undulating landscape of the Mobile Bay as the bridge carries US Route 90 over the Mobile River in Alabama. In February 1998, light rain drizzled on the bridge, and a weather station nearby recorded wind speeds of about 48 km/h (30 mph). Under these seemingly mild weather conditions, the normally immobile cable stays started to vibrate, and within moments, these nascent vibrations reached amplitudes of more than 1.2 m (4 ft). Alarmed by this event, the Alabama Department of Transportation (ALDOT) took immediate action to ensure the continued safety and serviceability of the bridge. A team of consultants was selected by ALDOT to investigate mitigation measures for the large-amplitude cable-stay vibrations. The fast-tracked comprehensive program planned and implemented to inspect, test, document, and evaluate the effects of the large-amplitude vibrations and the recommendation of retrofit measures that would limit future occurrences of such cable-stay vibrations on the Cochrane Bridge are described in detail.

scholarly journals Indoor Air Quality (IAQ): Accuracy of Natural Ventilation for Temperature, Air Flow Rate and Relative Humidity (RH) in School Building Classrooms

2018 ◽  
Vol 7 (3.9) ◽  
pp. 42
Author(s):  
Norsafiah Norazman ◽  
Adi Irfan Che Ani ◽  
Nor Haslina Ja’afar ◽  
Muhamad Azry Khoiry
Keyword(s):  
Air Quality ◽  
Relative Humidity ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Natural Ventilation ◽  
Air Flow ◽  
Weather Conditions ◽  
Potential Health ◽  
The Hours ◽  
Hot Weather

Indoor Air Quality (IAQ) is an essential matter in achieving students’ satisfaction for the learning process. Building’s orientation is a factor that may encourage sufficient natural ventilation for the classroom occupants. Inadequate ventilation is an issue for most existing classrooms. The purpose of this paper is to analyze the accuracy of natural ventilation in classrooms. Therefore, experimental on 20 classrooms has been conducted by using Multipurpose Meter at secondary school buildings in Malaysia. The findings indicated that the accuracy of natural ventilation testing was below the permissible limits throughout the hours monitored, thus this may cause potential health hazards to the students. Temperature and air flow rates were lower than 23 °C and 0.15 m/s respectively, it fulfilled the basic requirements as a standard learning environment. However, measurements taken showed the overall relative humidity (RH) in the classrooms can be categorized as acceptable with 40% to 70% range. On the basis of these findings, it is evident that naturally ventilated classrooms are important especially due to energy efficiency, whereas mechanical ventilation should only be installed as an alternative under extremely hot weather conditions.   

scholarly journals Sensitivity of local air quality to the interplay between small- and large-scale circulations: a large-eddy simulation study

2017 ◽  
Vol 17 (11) ◽  
pp. 7261-7276 ◽  
Author(s):  
Tobias Wolf-Grosse ◽  
Igor Esau ◽  
Joachim Reuder
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
Large Eddy Simulation ◽  
Air Pollutants ◽  
Large Scale ◽  
Wind Speeds ◽  
Street Level ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Air Pockets

Abstract. Street-level urban air pollution is a challenging concern for modern urban societies. Pollution dispersion models assume that the concentrations decrease monotonically with raising wind speed. This convenient assumption breaks down when applied to flows with local recirculations such as those found in topographically complex coastal areas. This study looks at a practically important and sufficiently common case of air pollution in a coastal valley city. Here, the observed concentrations are determined by the interaction between large-scale topographically forced and local-scale breeze-like recirculations. Analysis of a long observational dataset in Bergen, Norway, revealed that the most extreme cases of recurring wintertime air pollution episodes were accompanied by increased large-scale wind speeds above the valley. Contrary to the theoretical assumption and intuitive expectations, the maximum NO2 concentrations were not found for the lowest 10 m ERA-Interim wind speeds but in situations with wind speeds of 3 m s−1. To explain this phenomenon, we investigated empirical relationships between the large-scale forcing and the local wind and air quality parameters. We conducted 16 large-eddy simulation (LES) experiments with the Parallelised Large-Eddy Simulation Model (PALM) for atmospheric and oceanic flows. The LES accounted for the realistic relief and coastal configuration as well as for the large-scale forcing and local surface condition heterogeneity in Bergen. They revealed that emerging local breeze-like circulations strongly enhance the urban ventilation and dispersion of the air pollutants in situations with weak large-scale winds. Slightly stronger large-scale winds, however, can counteract these local recirculations, leading to enhanced surface air stagnation. Furthermore, this study looks at the concrete impact of the relative configuration of warmer water bodies in the city and the major transport corridor. We found that a relatively small local water body acted as a barrier for the horizontal transport of air pollutants from the largest street in the valley and along the valley bottom, transporting them vertically instead and hence diluting them. We found that the stable stratification accumulates the street-level pollution from the transport corridor in shallow air pockets near the surface. The polluted air pockets are transported by the local recirculations to other less polluted areas with only slow dilution. This combination of relatively long distance and complex transport paths together with weak dispersion is not sufficiently resolved in classical air pollution models. The findings have important implications for the air quality predictions over urban areas. Any prediction not resolving these, or similar local dynamic features, might not be able to correctly simulate the dispersion of pollutants in cities.

scholarly journals The visual-landscape analysis during the integration of high-rise buildings within the historic urban environment

2018 ◽  
Vol 33 ◽  
pp. 01044
Author(s):  
Vera A. Akristiniy ◽  
Elena A. Dikova
Keyword(s):  
Urban Development ◽  
Urban Environment ◽  
Urban Landscape ◽  
Landscape Analysis ◽  
High Rise ◽  
Visual Landscape ◽  
Key Aspects ◽  
Typological Structure ◽  
The City ◽  
Information Database

The article is devoted to one of the types of urban planning studies - the visual-landscape analysis during the integration of high-rise buildings within the historic urban environment for the purposes of providing pre-design and design studies in terms of preserving the historical urban environment and the implementation of the reconstructional resource of the area. In the article formed and systematized the stages and methods of conducting the visual-landscape analysis taking into account the influence of high-rise buildings on objects of cultural heritage and valuable historical buildings of the city. Practical application of the visual-landscape analysis provides an opportunity to assess the influence of hypothetical location of high-rise buildings on the perception of a historically developed environment and optimal building parameters. The contents of the main stages in the conduct of the visual - landscape analysis and their key aspects, concerning the construction of predicted zones of visibility of the significant historically valuable urban development objects and hypothetically planned of the high-rise buildings are revealed. The obtained data are oriented to the successive development of the planning and typological structure of the city territory and preservation of the compositional influence of valuable fragments of the historical environment in the structure of the urban landscape. On their basis, an information database is formed to determine the permissible urban development parameters of the high-rise buildings for the preservation of the compositional integrity of the urban area.

scholarly journals Aesthetic Preferences for Visual Quality of Urban Landscape in Derak High-Rise Buildings (Shiraz)

2017 ◽  
Vol 10 (5) ◽  
pp. 94 ◽  
Author(s):  
Reza Keshtkaran ◽  
Amin Habibi ◽  
Hamidreza Sharif
Keyword(s):  
Urban Landscape ◽  
Grid Method ◽  
Visual Quality ◽  
Landscape Design ◽  
High Rise ◽  
Q Sort ◽  
Aesthetic Preferences ◽  
Psychophysical Approach

The purpose of this study is to extract the indices of Aesthetic preferences for visual quality of urban landscape in high-rise buildings which contribute designers to make better decisions for designing urban landscape. As the research focuses on the high-rise buildings, this study goal address the question as follows: ‘What are aesthetic preferences in high-rise buildings? How can these preferences be developed and categorized?’ To achieve this objective, the Derak district of Shiraz city was selected as a case study area using Photo grid method and then all high-rise buildings in this area were identified and analyzed. Aesthetic preferences data were evaluated by Q-SORT method with the psychophysical approach. Eventually, aesthetic factors have been presented in two main categories: 'primary and distinctive'. Findings lead to the development of APPD model which suggests that when the landscape design of a building moves toward distinctive factors, the degree of its aesthetic preferences increases.

Meteorological study for Gangotri Glacier and its comparison with other high altitude meteorological stations in central Himalayan region

2007 ◽  
Vol 38 (1) ◽  
pp. 59-77 ◽  
Author(s):  
Pratap Singh ◽  
Umesh K. Haritashya ◽  
Naresh Kumar
Keyword(s):  
High Altitude ◽  
Meteorological Data ◽  
Weather Conditions ◽  
Meteorological Station ◽  
Himalayan Region ◽  
Valley Wind ◽  
Maximum Rainfall ◽  
Garhwal Himalayas ◽  
Wind Speeds ◽  
Gangotri Glacier

In spite of the vital role of high altitude climatology in melting of snow and glaciers, retreat or advancement of glaciers, flash floods, erosion and sediment transport, etc., weather conditions are not much studied for the high altitude regions of Himalayas. In this study, a comprehensive meteorological analysis has been made for the Gangotri Meteorological Station (Bhagirathi Valley, Garhwal Himalayas) using data observed for four consecutive melt seasons (2000–2003) covering a period from May to October for each year. The collected meteorological data includes rainfall, temperature, wind speed and direction, relative humidity, sunshine hours and evaporation. The results and their distribution over the different melt seasons were compared with available meteorological records for Dokriani Meteorological Station (Dingad Valley, Garhwal Himalayas) and Pyramid Meteorological Station (Khumbu Valley, Nepal Himalayas). The magnitude and distribution of temperature were found to be similar for different Himalayan regions, while rainfall varied from region to region. The influence of the monsoon was meagre on the rainfall in these areas. July was recorded to be the warmest month for all the regions and, in general, August had the maximum rainfall. For all the stations, daytime up-valley wind speeds were 3 to 4 times stronger than the nighttime down-valley wind speeds. It was found that the Gangotri Glacier area experienced relatively low humidity and high evaporation rates as compared to other parts of the Himalayas. Such analysis reveals the broad meteorological characteristics of the high altitude areas of the Central Himalayan region.

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