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1.
Computational Fluid Dynamics Modelling of the Pollution Dispersion and Comparison with Measurements in a Street Canyon in Helsinki 总被引:1,自引:0,他引:1
P. Neofytou M. Haakana A. Venetsanos A. Kousa J. Bartzis J. Kukkonen 《Environmental Modeling and Assessment》2008,13(3):439-448
A measuring campaign was conducted in a street canyon (Runeberg St.) in Helsinki in 2003–2004. The concentrations of NO
x
, NO2, PM10 and PM2.5 were measured at street level and at roof level at an urban background location. This study utilises the data measured from
1 Jan to 30 April, 2004, when wind speed and direction measurements were also conducted on-site at the roof level. The computational
fluid dynamics model ADREA-HF was used to compute the street concentrations, and the results were compared with the measurements.
The predictions for the selected cases agreed fairly well (within < 25 % for 15 min average values) with the measured data,
except for two cases: a windward flow in case of a low wind speed, and a moderate southerly flow parallel to the street canyon.
The main reasons for the differences of predictions and measurements are the negligence of traffic-induced turbulence in the
modelling and an under-prediction of ventilation of urban background air from a crossing street. Numerical results are presented
for various example cases; these illustrate the formation of the vortices in the canyon in terms of the wind direction and
speed and the influence of the characteristics of the flow fields on the concentration distributions. 相似文献
2.
A mixed-integer programming model that minimizes the social abatement cost is used to investigate whether a market equilibrium
condition could be reached in a newly proposed permit-trading market for nitrogen oxide control in Taiwan. Unlike in previous
studies, unit pollution abatement cost is determined endogenously by incorporating technology adoption as a binary decision
variable. The results show that when technologies are lumpy and irreversible, disequilibrium might occur due to firms’ inability
to manage their emission levels after installing equipment with fixed size and control capacity.
相似文献
Chao-ning LiaoEmail: |
3.
We derive conditions that must be satisfied by the primitives of the problem in order for an equilibrium in linear Markov
strategies to exist in some common property natural resource differential games. These conditions impose restrictions on the
admissible form of the natural growth function, given a benefit function, or on the admissible form of the benefit function,
given a natural growth function.
相似文献
Gérard GaudetEmail: |
4.
This paper offers an interpretation of the precautionary principle in terms of a safety target that a decision-maker has to
reach at a minimal cost in a robust way. A two-period model is used. The precautionary principle corresponds to a situation
in which the decision-maker, facing an ex ante indecision, is not able to reach a safe target from the initial condition in a worst-case framework. However, he can efficiently
succeed whenever the uncertainty at the second period is revealed to him. An example coping with the management of a renewable
resource illustrates the general results of the paper.
相似文献
Jean-Christophe PereauEmail: |
5.
Wen-Cheng Liu Jan-Tai Kuo Chih-Chieh Young Ming-Ching Wu 《Environmental Modeling and Assessment》2007,12(3):201-211
Numerical models are often used to evaluate the potential impact of human alternation of natural water bodies and to help
the design of the alternation to mitigate its impacts. In the past decade, three-dimensional hydrodynamic and reactive transport
modeling has matured from a research subject to a practical analysis technology. This paper presents a practical study in
which a three-dimensional hydrodynamic and water quality model [hydrodynamic eutrophication model (HEM-3D)] was applied to
determine the optimal location for treated wastewater discharged from marine outfall system in the Keelung harbor and the
adjacent coastal sea. First, model validation was conducted with respect to surface elevation, current, and water quality
variables measured in the Keelung harbor station and its coastal sea. The overall performance of the model was in qualitative
agreement with the available field data. The model was then used to evaluate several scenarios of the locations from marine
outfall system. Based on model simulation results, a location at the northeast of Ho-Ping Island was recommended for adoption
because the environmental impact is smaller than any other alternative.
相似文献
Wen-Cheng LiuEmail: |
6.
M. Kashir K. Zhang G. Achari R. G. Moore S. A. Mehta M. G. Ursenbach 《Environmental Modeling and Assessment》2008,13(2):265-274
A 2-D mathematical model to simulate the temperature distribution, coke formation, and change in residual extractable oil
during remediation by low-temperature oxidation (LTO) process was developed. Simulation results indicate that the spacing
between wells, pressure difference, and air-injection temperature and different well patterns influence the temperature distribution
and consequently the level of remediation in the soil. The model results for coke formation and residual extractable oil distribution
compared well with experimental results. The operating conditions—air-injection temperature of about 200°C, air-injection
pressure of 6 to 10 kPa, air-extraction pressure of −110 Pa, and wells spaced 1 m apart installed in a nine-spot pattern—provide
good remediation of hydrocarbons in soil by LTO process.
相似文献
G. AchariEmail: |
7.
This paper analyses the evolution of water consumption in Milan during the twentieth century. However, dealing with a century
time series raises some complicated statistic and econometric issues. To study the main research questions outlined by the
literature, as the presence of consumption habits and the link between consumption and price, we use a quite original approach
– based on intervention analysis and principal component analysis (PCA) – which seems to be more adequate than “regression-type”
approaches to study a so long time series. Results indicate (1) how some events have modified the normal evolution of per-capita
water consumption; (2) that per-capita water consumption is a very persistent series, namely, that water users should have
well-developed consumption habits; (3) that per-capita consumption and water price present a strong negative correlation.
相似文献
Mario NosvelliEmail: |
8.
This paper is concerned with the cost efficiency in achieving the Swedish national air quality objectives under uncertainty.
To realize an ecologically sustainable society, the parliament has approved a set of interim and long-term pollution reduction
targets. However, there are considerable quantification uncertainties on the effectiveness of the proposed pollution reduction
measures. In this paper, we develop a multivariate stochastic control framework to deal with the cost efficiency problem with
multiple pollutants. Based on the cost and technological data collected by several national authorities, we explore the implications
of alternative probabilistic constraints. It is found that a composite probabilistic constraint induces considerably lower
abatement cost than separable probabilistic restrictions. The trend is reinforced by the presence of positive correlations
between reductions in the multiple pollutants.
相似文献
Chuan-Zhong LiEmail: |
9.
I. V. Emelyanova G. E. Donald D. J. Miron D. A. Henry M. G. Garner 《Environmental Modeling and Assessment》2009,14(4):449-465
A probabilistic Bayesian method called weights of evidence (WofE) was used to develop a synthetic dataset of cattle farm locations at a national scale across Australia. The synthetic
dataset was required for the modelling of livestock movements with a view to assessing biosecurity implications. The WofE method is based on the analysis of spatial relationships between evidential patterns with respect to an event, such
as the actual location of a farm. The evidential patterns of cattle farms were derived from maps of land use, land tenure,
drainage systems, roads, settlements and long-term averaged rainfall. These evidential patterns were used for delineating
and ranking land areas suitable for cattle farming. For each evidential pattern statistics such as a positive weight, a negative weight and a contrast were calculated for estimating the degree of correlation between the evidential patterns and known farm locations. The integrated
evidential patterns of known farms were then used for estimating posterior probabilities and splitting land into five different
classes according to its suitability for farming.
相似文献
I. V. EmelyanovaEmail: |
10.
A Global Model Tracking Water, Nitrogen, and Land Inputs and Virtual Transfers from Industrialized Meat Production and Trade 总被引:1,自引:0,他引:1
Marshall Burke Kirsten Oleson Ellen McCullough Joanne Gaskell 《Environmental Modeling and Assessment》2009,14(2):179-193
Rising populations and incomes throughout the world have boosted meat demand by over 75% in the last 20years, intensifying
pressures on production systems and the natural resources to which they are linked. As a growing proportion of global meat
production is traded, the environmental impacts of production become increasingly separated from where the meat is consumed.
In this paper, we quantify the use of three important resources associated with industrial livestock production and trade—water,
land, and nitrogen—using a country-specific model that combines trade, agronomic, biogeochemical, and hydrological data. Our
model focuses on pigs and chickens, as these animals are raised predominantly in intensive systems using concentrated, compound
feeds. The results describe the geographical patterns of environmental resource use due to meat production, trade, and consumption.
We show that US feed, animal, and meat destined for export require almost as much nitrogen and land, and 20% more water, than
products destined for domestic consumption. Model results also demonstrate that among various production factors, improvements
in crop yields and animal feed conversion efficiencies result in the most significant reductions in environmental harm. By
explicitly tracking the externalities of meat production, we hope to bolster suppliers’ accountability and provide better
information to meat consumers.
相似文献
Kirsten OlesonEmail: |
11.
Kerstin Ronneberger Maria Berrittella Francesco Bosello Richard S. J. Tol 《Environmental Modeling and Assessment》2009,14(2):149-168
In this paper, the global agricultural land use model Kleines Land Use Model is coupled to an extended version of the computable general equilibrium model (CGE) Global Trade Analysis
Project in order to consistently assess the integrated impacts of climate change on global cropland allocation and its implication
for economic development. The methodology is innovative as it introduces dynamic economic land-use decisions based also on
the biophysical aspects of land into a state-of-the-art CGE; it further allows the projection of resulting changes in cropland
patterns on a spatially more explicit level. A convergence test and illustrative future simulations underpin the robustness
and potentials of the coupled system. Reference simulations with the uncoupled models emphasise the impact and relevance of
the coupling; the results of coupled and uncoupled simulations can differ by several hundred percent.
相似文献
Francesco BoselloEmail: Email: |
12.
The sensitivity of an integrated model to assess the potential for wind-borne spread of foot-and-mouth disease (FMD) to variations
in key parameters controlling different physical and biological processes was evaluated. The estimated number of farms at
risk is sensitive to the virus strain used and the accompanying effective contact rate. The C Noville strain increased the
estimated number of exposed farms ranked as high and medium risk of being infected by a factor of 5, compared to the baseline,
based on the O UKG 2001 strain. The inclusion of a model for biological ageing of the virus can also have a significant effect
on the concentration patterns arising from transport and dispersion of the virus. Its inclusion has the practical advantage
of markedly reducing the time required for the calculations. The estimated number of farms affected by exposure to high and
medium virus concentrations is not grossly sensitive to attenuation caused by temperature or relative humidity effects. Changes
in susceptibility to infection, as determined by the parameter θ in the exposure-risk model, does not change the configuration of the virus plumes, but it does change the distribution of
farms at risk by risk category. These findings suggest that a good understanding of characteristics (excretion rates from
infected animals, susceptibility of different species to infection, virus survival, etc.) of the virus strain involved in
an FMD outbreak is necessary to provide a reliable assessment of the risk of wind-borne spread. In the event of an incursion
of FMD, provision for laboratory studies on the virus will be an essential component of the disease response and should be
factored into contingency plans.
相似文献
X. YangEmail: |
13.
Global Warming Potential (GWP) is an index used to measure the cumulative radiative forcing of a tonne of greenhouse house
gas (GHG) relative to that of a ‘reference’ gas (CO2). Under the Kyoto Protocol, GWP can be used as a fixed index to govern the trade-off between different GHGs in a multi-gas approach to GHGs abatement. The use of fixed GWPs has
been criticized for not being very cost effective compared to the use of some flexible indices. To gain wider acceptance, however, a flexible index must also prove to be easy to use, and the economic gains from
its adoption must be significant. In this paper, we develop a flexible index based on the concept of marginal rather than cumulative or average global warming potentials. These marginal global warming potentials (MGWPs) can be endogenously
determined within a climate model given a particular climate objective based on radiative forcing level. The MGPWs are then
linked to the marginal abatement costs of the GHGs, which are also endogenously determined within an economic model. When
the two concepts are linked in this way, the result is a cost-effective way of achieving a particular climate change objective
with multigas abatement. We show that the savings in costs when using this flexible MGPWs can be significant, and more importantly,
they are not uniformly distributed across different regions.
相似文献
Claudia KemfertEmail: |
14.
Maggos T Plassais A Bartzis JG Vasilakos Ch Moussiopoulos N Bonafous L 《Environmental monitoring and assessment》2008,136(1-3):35-44
Titanium dioxide is the most important photocatalysts used for purifying applications. If a TiO2- containing material is left outdoors as a form of flat panels, it is activated by sunlight to remove harmful NOx gases during
the day. The photocatalytic efficiency of a TiO2-treated mortar for removal of NOx was investigated in the frame of this work. For this purpose a fully equipped monitoring
system was designed at a pilot site. This system allows the in situ evaluation of the de-polluting properties of a photocatalytic
material by taking into account the climatologic phenomena in street canyons, accurate measurements of pollution level and
full registration of meteorological data The pilot site involved three artificial canyon streets, a pollution source, continuous
NOx measurements inside the canyons and the source as well as background and meteorological measurements. Significant differences
on the NOx concentration level were observed between the TiO2 treated and the reference canyon. NOx values in TiO2 canyon were 36.7 to 82.0% lower than the ones observed in the reference one. Data arising from this study could be used to
assess the impact of the photocatalytic material on the purification of the urban environment. 相似文献
15.
Geological CO2 capture and storage (CCS) is among the main near-term contenders for addressing the problem of global climate change. Even
in a baseline scenario, with no comprehensive international climate policy, a moderate level of CCS technology is expected
to be deployed, given the economic benefits associated with enhanced oil and gas recovery. With stringent climate change control,
CCS technologies will probably be installed on an industrial scale. Geologically stored CO2, however, may leak back to the atmosphere, which could render CCS ineffective as climate change reduction option. This article
presents a long-term energy scenario study for Europe, in which we assess the significance for climate policy making of leakage
of CO2 artificially stored in underground geological formations. A detailed sensitivity analysis is performed for the CO2 leakage rate with the bottom-up energy systems model MARKAL, enriched for this purpose with a large set of CO2 capture technologies (in the power sector, industry, and for the production of hydrogen) and storage options (among which
enhanced oil and gas recovery, enhanced coal bed methane recovery, depleted fossil fuel fields, and aquifers). Through a series
of model runs, we confirm that a leakage rate of 0.1%/year seems acceptable for CCS to constitute a meaningful climate change
mitigation option, whereas one of 1%/year is not. CCS is essentially no option to achieve CO2 emission reductions when the leakage rate is as high as 1%/year, so more reductions need to be achieved through the use of
renewables or nuclear power, or in sectors like industry and transport. We calculate that under strict climate control policy,
the cumulative captured and geologically stored CO2 by 2100 in the electricity sector, when the leakage rate is 0.1%/year, amounts to about 45,000 MtCO2. Only a little over 10,000 MtCO2 cumulative power-generation-related emissions are captured and stored underground by the end of the century when the leakage
rate is 1%/year. Overall marginal CO2 abatement costs increase from a few €/tCO2 today to well over 150 €/tCO2 in 2100, under an atmospheric CO2 concentration constraint of 550 ppmv. Carbon costs in 2100 turn out to be about 40 €/tCO2 higher when the annual leakage rate is 1%/year in comparison to when there is no CO2 leakage. Irrespective of whether CCS deployment is affected by gradual CO2 seepage, the annual welfare loss in Europe induced by the implementation of policies preventing “dangerous anthropogenic
interference with the climate system” (under our assumption, implying a climate stabilisation target of 550 ppmv CO2 concentration) remains below 0.5% of GDP during the entire century.
相似文献
Koen SmekensEmail: |
16.
Pedrosa P 《Environmental monitoring and assessment》2007,129(1-3):137-150
This study investigates the inherent optical properties (IOP) of a Brazilian river during a non-natural, anthropogenically
mediated, toxic spill of a wood-pulping factory (the ‘Cataguazes accident’). The results indicated an outstanding transformation
in the river water chromophoric dissolved organic matter (CDOM) pools. For instance, increases in CDOM absorption coefficients,
a
CDOM
(λ), which were averaged at specific spectral intervals, , ranged from 58-fold at the UV-B and UV-A ranges to 95-fold at the PAR range. As a result, the water color expressed as CDOM
absorption at 440 nm, a
CDOM
(440), varied from 4.16 to 365.03 m-1. For S-coefficient, the variations ranged from ∼1.1 to 5.6-fold, respectively, at the 300–650 nm and UV-B range. The variability
of S as a proxy of dissolved chromophores was thus clearly influenced by the spectral range used. Optical proportions were also
investigated through the use of and S ratios at the UV-B, UV-A, and PAR ranges and, in the case of , also at the NIR range. This approach also showed clear variations between the water samples, likely reflecting changes in
the composition of optically active substances in the river system. As a whole, the findings obtained here indicated that
both the quantity and quality of the chromophoric material dissolved in the river water were greatly altered by the toxic
spill. The changes in the optical properties of the river water, although extreme and likely with no parallel in the literature,
were quite rapid as indicated by the optical resilience of the system. Overall, this study indicates that IOP might be thought,
and possibly used, as a metric tool for monitoring the state of waters and aquatic ecosystems. 相似文献
17.
This paper is based on the perception that the inertia of climate and socio-economic systems are key parameters in the climate
change issue. In a first part, it develops and implements a new approach based on a simple integrated model with a particular
focus on an innovative transient impact and adaptation modeling. In a second part, a climate–economy feedback is defined and characterized. The following results were found. 1) It has a long characteristic time, which lies between
50 and 100 years depending on the hypotheses; this time scale is long when compared to the system's other time scales, and
the feedback cannot act as a natural damping process of climate change. 2) Mitigation has to be anticipated since the feedback
of an emission reduction on the economy can be significant only after a 20-year delay and is really efficient only after at
least 50 years. 3) Even discounted, production changes due to an action on emissions are significant over more than one century.
4) The methodology of the Intergovernmental Panel on Climate Change (IPCC), which neglects the feedback from impacts to emissions,
is acceptable up to 2100, whatever is the level of impacts. This analysis allows also to define a climatic cost of growth as the additional climate change damages due to the additional emissions linked to economic growth.
相似文献
Stéphane HallegatteEmail: |
18.
Eighty-five measurement campaigns were performed repeatedly to compare the concentration variation profiles along two intra-urban
roads—one with open configuration and the other with street canyon effect. Fixed-effects panel data analysis was applied for
formulating a model to express the PM10 concentrations along intra-urban roads in terms of parameters like nearby central monitoring data, traffic counts and meteorological
conditions with an objective to analyze the PM10 concentration variation patterns along the two roads. Our findings reveal that traffic intensity and metrological conditions
exert influence on concentration variation for both types of road configurations while wind velocity only affect the pollutants
removal effectiveness of open road configuration. Further analysis unveils that the PM10 concentration distribution profiles within a compact city environment are not always uniform and are dependent on the road
configuration. Considerable PM10 concentration differences were observed along the street canyon, and 70% of their variations are attributed to variations
in their road aspect ratios. By contrast, no significant concentration difference is observed at open road configurations. 相似文献
19.
The goal of this study is to investigate numerically the wind flow and pollutant dispersion within an urban street canyon containing an elevated expressway and reveal the impacts of elevated expressway on the atmospheric environment in the canyon. A two-dimensional numerical model for simulating airflow and pollutant dispersion inside urban street canyons is first developed based on the Reynolds-averaged Navier–Stokes equations coupled with the standard k???ε turbulence model and the convection–diffusion equation for passive species transport, and then it is validated against a wind tunnel experiment. It was found that the model-predicted results agree well with the experimental data. Having established this, the wind fields and pollutant distributions in the canyon containing an elevated expressway are evaluated. The numerical results show that the expressway height above the street floor and the gap distance between the expressway and the building wall have considerable influence on airflow and pollutant level inside a canyon: (1) the vortical flow structure in the canyon varies with the expressway height for a constant gap distance, under certain expressway heights, only one main clockwise vortex is formed, while under others one main vortex as well as one or two secondary vortices above and below the expressway are created; (2) the pollutant level within the canyon increases when an expressway is placed in the canyon, especially when the expressway height equals the building height the flow velocities in the canyon are drastically reduced and air exchange in and above the canyon is seriously impeded by the expressway, which leads to a much higher pollution level in the canyon; and (3) the wider gap distance is favorable to pollutant removal from the canyon. 相似文献
20.
Jaakko Kukkonen Esko Valkonen Jari Walden Tarja Koskentalo Ari Karppinen Ruwim Berkowicz Raimo Kartastenpää 《Environmental monitoring and assessment》2000,65(1-2):371-379
A measuring campaign was conducted in the street canyon 'Runeberg street' in Helsinki in 1997. Hourly concentrations of carbon monoxide (CO), nitrogen oxides (NOX), nitrogen dioxide (NO2) and ozone (O3) were measured at the street and roof levels, and the relevant hourly meteorological parameters were measured at the roof level. The hourly street level measurements and on-site electronic traffic counts were conducted during the whole year 1997, and roof level measurements were conducted during approximately two months, from 3 March to 30 April in 1997. The Operational Street Pollution Model (OSPM) was used to calculate the street concentrations and the results were compared with the measurements. The overall agreement between measured and predicted concentrations was good for CO and NOx, but the model slightly overestimated the measured concentrations of NO2. The database, which contains all measured and predicted data, is available for a further testing of other street canyon dispersion models. 相似文献