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1.
据1983年南京北郊等容球扩散试验资料,估算得该地区的大气扩散参数,并与国外其他示踪扩散试验得的结果、国内江苏仪征试验结果作比较分析。  相似文献   

2.
利用牙克石电厂野外平衡球观测资料分别计算了不同稳定度下的大气扩散参数,并与其他结果进行了比较,揭示了牙克石地区大气湍流扩散特征。试验结果仅适用于远距离的高架源排烟计算。  相似文献   

3.
本文根据宁波北仑地区的大气扩散试验研究,分别提出了适合本地区高架源扩散模式和低矮源或地面源扩散模式使用的大气湍流扩散参数。为该地区的大气环境影响评价及大气环境质量总量控制的数学模型的建立提供了实用参数。  相似文献   

4.
为研究机动车辆排出的污染物在大气中的扩散规律,在北京做了小风条件下的街谷示踪试验。当楼顶风速u接近或大于1米/秒时,街谷内可形成一稳定的原生涡;u<0.6米/秒时原生涡将消失。对于楼之间空间较小的街谷,背风面和迎风面的示踪剂浓度平均比值可达8。浓度值沿楼层高度无明显变化;由于快车路旁松墙的阻挡和抬升作用,可能造成沿高度方向楼层中段的浓度偏高。在街谷外,除下风方路面上有一按下风距离的负幂指数衰减的浓度分布外,上风方路面上也有一按较大负幂指数衰减的分布。根据上述试验,给出了用以预测街谷中机动车辆排出的惰性气体污染物的扩散模式;模式中,对原生涡和小尺度湍流,做了分别处理。  相似文献   

5.
姜平  史润选 《贵州气象》1994,18(2):39-44
1前言为开发贵州省六盘水地区丰富的煤炭资源发展地区经济,就地把资源优势转化为电能优势,提高贵州省西部地区供电的可靠性,水城电厂拟扩建2×200MW发电机组工程,烟囱高度180米.为了预测扩建工程排放大气污染物对该地区大气环境质量的影响,以便确定合理的烟气控制目标和制定综合的污染治理方案,需要根据该地区的地形、气象条件分析污染物在大气中的输送、扩散规把,进而对污染物的时空分布进行定量描述。水城电厂位于六盘水市境内钟山区北两,扩建工程建在东一西走向的狭长山谷之中,山谷南北两侧高山陡峻,山峦重叠,山谷内与南北…  相似文献   

6.
南京市大气NOx扩散规律与防治对策研究   总被引:6,自引:0,他引:6       下载免费PDF全文
以实用的多源大气扩散模型计算了南京市点源、面源及流动源等各类污染源对地面及不同高度的关心点上N0。年平均浓度分布状况及其各类源的平均浓度贡献率,分析了影响NO。在大气中扩散的主要因素,着重对交通源的排污扩散进行研究。发现2000年南京交通源对大气中NO。浓度的贡献率在市区绝大多数地区已超过70%。另外,还将美国的CAI.INE3模式引入南京。模拟了2000年交通源的排污扩散状况。结果表明,经过修正的CAuNE3模式基本上能合理地描述城市道路N0。的污染状况。根据城市管理部门给出的3种NO。减排方案,计算了实施这些方案后大气中NO。污染状况。结果表明。不能继续维持南京市的交通现状。而必须实施机动车车辆控制或排放因子的限制。  相似文献   

7.
利用离海岸约800 m的气象铁塔上获得的数据,对辽东湾地区大气扩散因子的特征进行了研究。结果表明:在核设施正常运行期间,主要以高架排放方式为主。当风速较大时,烟羽抬升高度低于30 m。  相似文献   

8.
9.
来宾冶炼厂区大气扩散规律探讨   总被引:1,自引:1,他引:1  
1987年元月和七月我们在来宾冶炼厂进行大气探测试验。获得了该地区大气扩散的有关气象资料,从而为该地区污染潜势预报提供了重要的气象参数。  相似文献   

10.
在进行大气环境质量的评价和预测时,对大气扩散规律的分析是十分重要的.目前普遍采用的方法之一是用观测平衡气球轨迹的方法计算扩散参数.本文对1989年冬季,在玛纳斯电厂用平衡气球轨迹法进行的大气湍流扩散试验资料作了分析计算,并与P-G(帕斯圭尔一吉福德)结果进行了比较,提出了厂区不同稳定度条件下的大气湍流扩散参数σ_y和σ_z,为研究和摸清该区大气污染物的扩散能力提供了依据.  相似文献   

11.
In analogy with two-dimensional turbulent layers, the surface layer (where wall similarity is fulfilled) and the region near the outer edge of the boundary layer (where the flow described by the velocity defect belongs to then-parameter family) may be postulated to exist for the atmospheric boundary layer over a wavy surface. The matching of the two regions yields a resistance law.  相似文献   

12.
本文采用数值方法求解平流扩散方程,对太原市的一次示踪物实验进行了大气扩散的数值模拟。模拟结果表明:采用数值方法准确地反映出了由于风的切变而导致的污染物烟羽的转向,能较好地模拟复杂地形下太原市污染物的输送扩散过程。  相似文献   

13.
The atmospheric heat budget in summer over Asia monsoon area   总被引:1,自引:0,他引:1  
For better understanding the mechanism of monsoon formation and designing the numerical simulation of the general atmospheric circulation, a new approach of calculating atmospheric radiation is proposed to investigate the distribution of the atmospheric heat source, and the budget of heat component is recalculated. The results show that there is a tremendous atmospheric heat source region over central India, northeast of the Bay of Bengal, east of the South China Sea and about 10 °N at the west Pacific, among which the heating center with a maximum heating rate of 8 ℃/day is located over the Bay of Bengal and the average rate in the Plateau is about 1 ℃/day.  相似文献   

14.
本文为一次沿海岸边翻越二维山丘的扩散实验.结果表明:在一定条件下,假若两层空气的湍流强度和尺度的比值不大,当烟羽从上层侵入到下层较强混合气层时,不一定产生燻烟型扩散,仅表现为扩散参数在一定水平距离上的跃变.本文同时介绍了两组风洞实验的结果,其目的在于说明扩散参数跃变存在的事实.  相似文献   

15.
16.
This paper is written to report observations of the structure of the atmospheric surface layer over a coastal industrialized equatorial area. The observations were recorded at Prai Industrial Park, Penang (5° 22′ N, 100° 23′ E) a relatively simple terrain area during the south-west monsoon season in the period of three months using slow response systems. The limitations of the instruments used and its effects on the results are discussed. Wind turbulence and temperature were measured on a 10 m tower and analyzed using eddy correlation method and Monin–Obukhov similarity relations to obtain the normalized standard deviation of longitudinal (σu/u), lateral (σv/u) and vertical wind velocity fluctuations (σw/u) with respect to stability parameter z/L. From the results of the analysis, we found that most of turbulence is generated by shear or mechanical force. It was found that the average neutral value of σu/u is 2.35, 1.98 for σv/u and 1.47 for σw/u with a significantly lower than the proportionality to the power of 1/3 during unstable atmospheric conditions, and thus do not obey Monin–Obukhov similarity theory. It was observed that σu/u and σv/u values increase linearly in the range of 0 < z/L < 2 and fairly well correlated while σw/u does not.  相似文献   

17.
Summary A dispersion modeling system consisting of a three-dimensional PBL model NHECM (non-hydrostaticE- closure model) and SLPTDM (seven-level puff transport and diffusion model) is developed to simulate the transport and dispersion of pollutant over coastal complex terrain. As an application of the system, the transport and dispersion of SO2 released from an elevated point source are simulated during typical sea-land breeze circulation in the Hongkong-Shenzhen area of China. The NHECM provides time-varying, three-dimensional distributions of wind and turbulence fields to the SLPTDM. The NHECM predictions compare well with observational data. Reflection of both the ground and the mixing layer top and penetration of the mixing layer top are improved in the SLPTDM. Results obtained from the system indicate that temporal variation and nonuniformity of airflow and turbulence obviously affect the concentration distributions, especially during the sea-land breeze transition period. A diurnal cycle of the GLC (ground-level concentration) is discussed. The results are compared with those estimated using a Gaussian model. The study's results illustrate the complexity of the dispersion patterns due to diurnal effects and mesoscale circulations, and demonstrate the potential of the mesoscale atmospheric dispersion modeling system for studies of air quality in complex terrain.With 8 Figures  相似文献   

18.
19.
Summary The impact of the changes on soil cover and land use brought about by the construction of the Sobradinho Dam in the semi-arid region of the S?o Francisco River Hydrographic Basin is analyzed by means of a numerical model RAMS. Disregarding the influence of a large scale flow, a set of factors were responsible for the creation of a rather complex circulation system that includes mountain-valley winds, lake breeze (LB) and non-conventional circulation all induced by the surface non-homogeneous aspect. Results have demonstrated that the implementation of works of such magnitude brings about environmental changes in an area that stretches far beyond the surroundings of the reservoir. The soil cover alterations due to the ever increasing development of the area with the presence of irrigated crops in a sparsely vegetated region (caatinga) does affect land surface characteristics, occasioning for that matter the splitting of the available energy into latent and sensible heat fluxes. LB behavior varies in accordance with atmospheric conditions and also in view of the type of vegetation found in the lake surrounding areas. Hydro availability in root zones, even under adverse atmospheric conditions (high temperature and low air humidity) brings up the high rates of evaporation and plant transpiration that contribute towards the increase of humidity and the fall of temperature in lower atmospheric layers.  相似文献   

20.
2009年石家庄地区大气气溶胶的飞机探测研究   总被引:2,自引:2,他引:2  
马梁臣  银燕 《气象科学》2014,34(1):47-53
利用2009年石家庄地区不同季节的3次机载粒子探测系统PMS(Particle Measurement System)的探测资料,结合地面天气形势、风场和探空资料对石家庄地区,晴空背景下大气气溶胶的统计特征、数浓度、平均粒径的垂直分布特征以及谱分布特征进行了分析。结果表明:晴天条件下气溶胶的数浓度随高度递减,粒径随高度变化不大;在数值上,4月16日气溶胶数浓度和粒径最大,其次是10月15日,最小的是6月10日,3次粒径变化幅度都不大;逆温层底层气溶胶明显积累,气溶胶浓度在1.5 km以下大气边界层内明显高于其他层次,逆温层的高度和厚度影响气溶胶的分布;3次不同季节晴天背景下石家庄地区气溶胶谱型基本一致呈单峰分布,小于0.3μm的细粒子对气溶胶的数浓度贡献最大。  相似文献   

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