scholarly journals Atmospheric Dispersion of PM10 in an Urban Area

2014 ◽  
Vol 8 (2) ◽  
pp. 91-99 ◽  
Author(s):  
Carmelia Mariana Dragomir ◽  
Daniel Eduard Constantin ◽  
Mirela Voiculescu ◽  
Lucian Puiu Georgescu Georgescu
Keyword(s):  
Environmental Protection Agency ◽  
Dispersion Model ◽  
Atmospheric Dispersion ◽  
City Centre ◽  
Anthropogenic Emissions ◽  
Dispersion Models ◽  
Protection Agency ◽  
Using Data ◽  
The City ◽  
Pm10 Emissions

Abstract One way of monitoring the atmospheric pollution is to estimate anthropogenic emissions. This paper presents a study of PM10 emissions in a city SE of Romania (Braila) for the period 2009-2012. PM10 emissions decrease from 304.75 t in 2009 to 78.01 t in 2012. Using data from the Environmental Protection Agency Braila and the METI-LIS dispersion model, four maps were produced in order to estimate the spatial distribution of PM10 emission in each year. Results of dispersion models show that the air quality can change abruptly between points at few meters away. Expectedly, PM10 emissions increase towards the centre of the city centre, are generally higher in the vicinity of busy streets and roads.

The Hornsby Bend Hyacinth Facility in Austin, Texas

1987 ◽  
Vol 19 (10) ◽  
pp. 41-49 ◽  
Author(s):  
Ray Dinges ◽  
Jim Doersam
Keyword(s):  
Environmental Protection ◽  
Environmental Protection Agency ◽  
Plant Material ◽  
Animal Species ◽  
Performance Data ◽  
Operational Performance ◽  
Fish Production ◽  
Protection Agency ◽  
Functional Characteristics ◽  
The City

The Hornsby Bend Hyacinth Facility, the first such system built under the U. S. Environmental Protection Agency “Construction Grants Program”, represents the culmination of over a decade of experience at the City of Austin with hyacinth treatment. The facility consists of three culture basins 265 m in length with an area of 1.6 ha. To permit year-round hyacinth culture, basins are covered with a 2.06 ha unitary greenhouse structure. Fenced exclusion areas at intervals along sides of basins serve as natural aerators and enhance fish production. The system, operated in an aerobic mode, was designed to daily treat about three million liters of sludge lagoon supernatant. Exclusion of large vertebrate predators and stocking of basins with selected animal species will provide a unique ecosystem. Basins were planted with hyacinth in late October, 1985 and discharge commenced on February 3, 1986. Functional characteristics and ecological considerations of the facility are discussed and operational performance data are presented. Maintenance harvesting of hyacinth and disposition of plant material are described. Application of greenhoused hyacinth treatment systems are addressed.

scholarly journals Understanding Spatial Variability of NO2 in Urban Areas Using Spatial Modelling and Data Fusion Approaches

Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 179
Author(s):  
Said Munir ◽  
Martin Mayfield ◽  
Daniel Coca
Keyword(s):  
Data Fusion ◽  
Spatial Variability ◽  
Urban Areas ◽  
Road Traffic ◽  
Dispersion Model ◽  
Low Cost ◽  
Spatial Modelling ◽  
City Centre ◽  
Small Scale ◽  
The City

Small-scale spatial variability in NO2 concentrations is analysed with the help of pollution maps. Maps of NO2 estimated by the Airviro dispersion model and land use regression (LUR) model are fused with measured NO2 concentrations from low-cost sensors (LCS), reference sensors and diffusion tubes. In this study, geostatistical universal kriging was employed for fusing (integrating) model estimations with measured NO2 concentrations. The results showed that the data fusion approach was capable of estimating realistic NO2 concentration maps that inherited spatial patterns of the pollutant from the model estimations and adjusted the modelled values using the measured concentrations. Maps produced by the fusion of NO2-LCS with NO2-LUR produced better results, with r-value 0.96 and RMSE 9.09. Data fusion adds value to both measured and estimated concentrations: the measured data are improved by predicting spatiotemporal gaps, whereas the modelled data are improved by constraining them with observed data. Hotspots of NO2 were shown in the city centre, eastern parts of the city towards the motorway (M1) and on some major roads. Air quality standards were exceeded at several locations in Sheffield, where annual mean NO2 levels were higher than 40 µg/m3. Road traffic was considered to be the dominant emission source of NO2 in Sheffield.

scholarly journals Potential impacts of mercury released from thawing permafrost

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Kevin Schaefer ◽  
Yasin Elshorbany ◽  
Elchin Jafarov ◽  
Paul F. Schuster ◽  
Robert G. Striegl ◽  
...  
Keyword(s):  
United States ◽  
Environmental Protection Agency ◽  
Mechanistic Model ◽  
Anthropogenic Emissions ◽  
Protection Agency ◽  
Yukon River ◽  
Naturally Occurring ◽  
Emissions Scenarios ◽  
Thawing Permafrost ◽  
Emissions Scenario

Abstract Mercury (Hg) is a naturally occurring element that bonds with organic matter and, when converted to methylmercury, is a potent neurotoxicant. Here we estimate potential future releases of Hg from thawing permafrost for low and high greenhouse gas emissions scenarios using a mechanistic model. By 2200, the high emissions scenario shows annual permafrost Hg emissions to the atmosphere comparable to current global anthropogenic emissions. By 2100, simulated Hg concentrations in the Yukon River increase by 14% for the low emissions scenario, but double for the high emissions scenario. Fish Hg concentrations do not exceed United States Environmental Protection Agency guidelines for the low emissions scenario by 2300, but for the high emissions scenario, fish in the Yukon River exceed EPA guidelines by 2050. Our results indicate minimal impacts to Hg concentrations in water and fish for the low emissions scenario and high impacts for the high emissions scenario.

Threats related to accidental release of LPG in rail transport

2020 ◽  
Vol 73 (1) ◽  
pp. 37-54
Author(s):  
Anna Dmochowska
Keyword(s):  
Mathematical Model ◽  
Environmental Protection Agency ◽  
Emergency Services ◽  
Rail Transport ◽  
Protection Agency ◽  
Software Suite ◽  
Accidental Release ◽  
Dangerous Substances ◽  
Emergency Scenarios ◽  
The City

The transport of dangerous substances is potentially hazardous to people and the environment. Failures of installations or equipment as well as errors of people who operate them may contribute to uncontrolled release of a dangerous substance, creating a chemical threat as a result of contamination, fire or explosion. The aim of the study was to analyse the extent and scale of threats to residents and emergency services in the event of an accidental release of LPG from a tank or a railway tank in built-up areas. The inspiration was a train disaster that happened in in Italy the city of Viareggio in 2009. The Aloha program was used for needs of the research. The presented hazard zones were generated on the basis of emergency scenarios for the release of LPG. During the modelling of danger zones, parameters of emergency release of 45 tons of gas from a railway tanker in the city were reproduced. Five scenarios were devised that could occur during the uncontrolled release of LPG into the atmosphere. For each of them, the effects are listed of failures that residents of the built-up area in which the event occurred may potentially encounter. In the summary of the work, reference was made to the discussed railway disaster and its effects, as well as to modelled emergency release scenarios. An evaluation was made of the application used. It provides an example of using a mathematical model. The application is developed by The Cameo Software Suite, in cooperation with the National Oceanic and Atmospheric Administration and the Environmental Protection Agency.

scholarly journals GEOSTATISTICS FOR AIR QUALITY MAPPING: CASE OF BAGUIO CITY, PHILIPPINES

2019 ◽  
Vol XLII-4/W19 ◽  
pp. 353-359
Author(s):  
R. V. Ramos ◽  
A. C. Blanco
Keyword(s):  
Air Quality ◽  
Dispersion Model ◽  
Atmospheric Dispersion ◽  
Spatial Variations ◽  
Dispersion Modeling ◽  
Dispersion Models ◽  
Night Time ◽  
Smoothing Factor ◽  
Pollutant Concentrations ◽  
Atmospheric Dispersion Models

Abstract. Mapping of air quality are often based on ground measurements using gravimetric and air portable sensors, remote sensing methods and atmospheric dispersion models. In this study, Geographic Information Systems (GIS) and geostatistical techniques are employed to evaluate coarse particulate matter (PM10) concentrations observed in the Central Business District of Baguio City, Philippines. Baguio City has been reported as one of the most polluted cities in the country and several studies have already been conducted in monitoring its air quality. The datasets utilized in this study are based on hourly simulations from a Gaussian-based atmospheric dispersion model that considers the impacts of vehicular emissions. Dispersion modeling results, i.e., PM10 concentrations at 20-meter interval, show that high values range from 135 to 422 μg/mm3. The pollutant concentrations are evident within 40 meters from the roads. Spatial variations and PM10 estimates at unsampled locations are determined using Ordinary Kriging. Geostatistical modeling estimates are evaluated based on recommended values for mean error (ME), root mean square error (RMSE) and standardized errors. Optimal predictors for pollutant concentrations at 5-meter interval include 2 to 5 search neighbors and variable smoothing factor for night-time datasets while 2 to 10 search neighbors and smoothing factors 0.3 to 0.5 were used for daytime datasets. Results from several interpolation tests indicate small ME (0.0003 to 0.0008 μg/m3) and average standardized errors (4.24 to 8.67 μg/m3). RMSE ranged from 2.95 to 5.43 μg/m3, which are approximately 2 to 3% of the maximum pollutant concentrations in the area. The methodology presented in this paper may be integrated with atmospheric dispersion models in refining estimates of pollutant concentrations, in generating surface representations, and in understanding the spatial variations of the outputs from the model simulations.

scholarly journals Specificities of suburbanisation in post-socialist context: New housing construction in metropolitan region of Prague 1997-2005

Geografie ◽  
2007 ◽  
Vol 112 (3) ◽  
pp. 334-356
Author(s):  
Luděk Sýkora ◽  
Darina Posová
Keyword(s):  
Metropolitan Area ◽  
Metropolitan Region ◽  
City Centre ◽  
Housing Construction ◽  
Compact City ◽  
Large Share ◽  
Suburban Areas ◽  
Using Data ◽  
The City

The article analyses residential suburbanisation in Prague metropolitan region using data about new housing construction in the period of 1997-2005. Findings show that despite suburban areas account for large share of newly constructed housing, its majority is built within the compact city. Large share of new housing construction in the compact city indicates the vitality and strength of urban alternatives to suburbanisation. In addition, the paper illustrates the strengthening position of Prague metropolitan area within the country and discuses characteristics of new housing construction in the relation to the increasing distance from the city centre.

scholarly journals Ranking uncertainties in atmospheric dispersion modelling following the accidental release of radioactive material

2020 ◽  
Vol 55 ◽  
pp. S51-S55 ◽  
Author(s):  
S.J. Leadbetter ◽  
S. Andronopoulos ◽  
P. Bedwell ◽  
K. Chevalier-Jabet ◽  
G. Geertsema ◽  
...  
Keyword(s):  
Early Phase ◽  
Source Term ◽  
Dispersion Model ◽  
Atmospheric Dispersion ◽  
Radioactive Material ◽  
Dispersion Modelling ◽  
Dispersion Models ◽  
Sources Of Uncertainty ◽  
Accidental Release ◽  
Modelling Uncertainty

During the pre-release and early phase of an accidental release of radionuclides into the atmosphere there are few or no measurements, and dispersion models are used to assess the consequences and assist in determining appropriate countermeasures. However, uncertainties are high during this early phase and it is important to characterise these uncertainties and, if possible, include them in any dispersion modelling. In this paper we examine three sources of uncertainty in dispersion modelling; uncertainty in the source term, uncertainty in the meteorological information used to drive the dispersion model and intrinsic uncertainty within the dispersion model. We also explore the possibility of ranking these uncertainties dependent on their impact on the dispersion model outputs.

Exploring forecast variability during volcanic ash cloud events 

2021 ◽  
Author(s):  
Frances Beckett ◽  
Ralph Burton ◽  
Fabio Dioguardi ◽  
Claire Witham ◽  
John Stevenson ◽  
...  
Keyword(s):  
Real Time ◽  
Volcanic Ash ◽  
Atmospheric Transport ◽  
Dispersion Model ◽  
Meteorological Data ◽  
Atmospheric Dispersion ◽  
Dispersion Models ◽  
British Geological Survey ◽  
Volcanic Ash Cloud ◽  
Ash Cloud

<p>Atmospheric transport and dispersion models are used by Volcanic Ash Advisory Centers (VAACs) to provide timely information on volcanic ash clouds to mitigate the risk of aircraft encounters. Inaccuracies in dispersion model forecasts can occur due to the uncertainties associated with source terms, meteorological data and model parametrizations. Real-time validation of model forecasts against observations is therefore essential to ensure their reliability. Forecasts can also benefit from comparison to model output from other groups; through understanding how different modelling approaches, variations in model setups, model physics, and driving meteorological data, impact the predicted extent and concentration of ash. The Met Office, the National Centre for Atmospheric Science (NCAS) and the British Geological Survey (BGS) are working together to consider how we might compare data (both qualitatively and quantitatively) from the atmospheric dispersion models NAME, FALL3D and HYSPLIT, using meteorological data from the Met Office Unified Model and the NOAA Global Forecast System (providing an effective multi-model ensemble). Results from the model inter-comparison will be used to provide advice to the London VAAC to aid forecasting decisions in near real time during a volcanic ash cloud event. In order to facilitate this comparison, we developed a Python package (ash-model-plotting) to read outputs from the different models into a consistent structure. Here we present our framework for generating comparable plots across the different partners, with a focus on total column mass loading products. These are directly comparable to satellite data retrievals and therefore important for model validation. We also present outcomes from a recent modelling exercise and discuss next steps for further improving our forecast validation.</p>

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