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1.
Air pollution represents a significant fraction of the total mortality estimated by the World Health Organization (WHO) global burden of disease projec?t (GBD). The present paper discusses the characteristics of trace gases (O3, NO, NO2, and CO) and particulate matter (PM10 and PM2.5) in two Asian megacities, Delhi (India) and Beijing (China). A continuous measurement of trace gases and particulate matter are considered from 12 measuring sites in Beijing and 8 sites in Delhi. Over Beijing, the annual average of PM2.5, PM10, O3, NO2, and CO is, respectively, 85.3, 112.8, 58.7, and 53.4 μg/m3 and 1.4 mg/m3, and, respectively, over Delhi 146.5, 264.3, 24.7,and 19.8 μg/m3 and 1.73 mg/m3. From the spatial variations of pollutants, the concentrations of particulate matter and trace gases are observed to be much higher in the urban areas compared to the suburban areas. The higher average concentrations of PM10 and PM2.5 over Delhi and Beijing are observed during winter season compared with other seasons. The maximum diurnal variation of PM10 concentration is observed during winter season over Beijing and Delhi. The comparison of trace gases shows that the O3 concentrations during daytime are obviously higher compared with nighttime, and the highest diurnal variation of O3 is observed during summer. The concentrations of CO are highest during winter season, and higher concentrations are observed during nighttime compared to daytime. The O3 and CO show negative correlation over Beijing and Delhi. The negative correlation between O3 and NO2 is merely observed over Beijing, while CO and NO2 concentrations, in contrast, show positive correlation over Beijing.  相似文献   

2.
侯学煜 《土壤学报》1950,1(2):107-121
1945年10月中旬,作者留印三月另一周,曾作三次野外调查,计包括印缅边区、恒河平原及喜马拉雅山东南麓等三区,茲先将大吉岭区调查结果,草成此文  相似文献   

3.
Recently, specific air quality problems have been detected in the northern region of Portugal. The nitrogen oxide (NO2) annual limit value has been surpassed at several air quality monitoring stations in the northern region, and according to European legislation, air quality plans must be designed and implemented to reduce those levels. The analysis of the air quality data from the stations concerning NO2 exceedances indicates that traffic is responsible for an increase of more than 40?% compared with the urban background value. Specific measures to reduce NOx emissions have been selected and are related not only mainly to the traffic sector but also to the industrial and residential combustion sectors. The main objective of this study is to investigate the impact of the selected measures on the ambient levels of NO2 in northern Portugal using a numerical modelling tool??The Air Pollution Model (TAPM). TAPM was applied over the study region using a 120?×?120-km2 simulation domain and a spatial resolution of 4.8?×?4.8?km2. The entire year of 2010 was simulated and was set as the base year to analyse the impact of the selected measures. Two scenarios have been defined and simulated: the base situation, which considers current NOx emissions, and the reduction scenario for which NOx emissions were re-estimated considering the implementation of the measures. The modelling results demonstrate a decrease of 4?C5???g?m?3 in the annual NO2 levels in the study region. Moreover, the implementation of the selected measures will allow compliance with the NO2 annual limit values in three of the five air quality stations that measured levels surpassing those established by legislation. This situation demands additional measures that should be implemented at the local level and that particularly focus on the traffic sector.  相似文献   

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5.
The study aimed to evaluate the impact of shifting cultivation on soil quality, in Wokha district of Nagaland, using weighted soil quality index (SQIw). Four forest sites and three sites under shifting cultivation were selected and physical (texture and bulk density) and chemical (pH, electrical conductivity, cation exchange capacity, organic carbon, available N, P, K, exchangeable cations) parameters were analyzed. The SQIw was calculated on a minimum data set selected by principal component analysis, followed by varimax rotation algorithm and through subsequent normalization of the parameters using the linear scoring function. Significant (P < 0.05) variations in SQIw were found across the depth of the soil and land use according to severity of factors associated with land use. Three different classes of soil quality were also identified: high quality (SQIw > 0.70) for two forest soils (FS1 and FS2) and land under shifting cultivation (JH1), low quality (SQIw < 0.50), only to FS3, and intermediate quality (0.50 < SQI < 0.70) in all other soils. The approach used in this study proved to be sensitive to evaluate the soil quality, however further research is required to better understand the sustainability of shifting cultivation by including more physical, biological and chemical indicators.  相似文献   

6.
7.
Soils are the third biggest sink of carbon on the earth. Hence, suitable land uses for a climatic condition are expected to sequester optimum atmospheric carbon in soils. But, information on how climatic conditions and land uses influence carbon accumulation in the soils on the Himalayan Mountains is not known. This study reports the impact of four climatic conditions (sub-tropical, altitude: 500–1200 m; temperate 1200–2000 m; lower alpine 2000–3000 m; upper alpine, 3000–3500 m) and four land uses (forest, grassland, horticulture, agriculture) on the concentrations and stocks of soil organic carbon (SOC) in upper (0–30 cm) and deeper (30–100 cm) soil depths on the western Himalayan Mountains of India. The study also explored the drivers which influenced the SOC stock build up on the mountains. Rainfall and soil moisture showed quadratic relations, whereas temperature declined linearly with the altitude. SOC stock as well as concentration was the highest (101.8 Mg ha− 1 in 0–30 cm, 227.97 Mg ha− 1 in 0–100 cm) in temperate and the lowest in sub-tropical climate (37 Mg ha− 1 in 0–30 cm, 107.04 Mg ha− 1 in 0–100 cm). Pattern of SOC stock build up across the altitude was: temperate > lower alpine > upper alpine > sub-tropical. SOC stocks in all land uses across the climatic conditions, except agriculture in lower alpine, was higher (0.7 to 41.6%) in the deeper than upper soil depth. SOC stocks in both the depths showed quadratic relations with soil temperature and soil moisture. Other factors like fine soil particles, land-use factor and altitude influenced positively whereas slope and pH, negatively to the SOC stocks. In all climatic conditions, other than temperate, SOC stocks were greater in natural ecosystems like forests and pastures (112.5 to 247.5 Mg ha− 1) than agriculture (63 to 120.4 Mg ha− 1). In temperate climate, SOC stock in agriculture (253.6 Mg ha− 1) on well formed terraces was a little higher than forest (231.3 Mg ha− 1) on natural slope. These observations, suggest that land uses on temperate climate may be treated as potential sinks for sequestration of the atmospheric carbon. However, agriculture in subtropical climate need to be pursued with due SOC protection measures like the temperate climate for greater sequestration of the atmospheric carbon.  相似文献   

8.
Journal of Soils and Sediments - Soil is the prime source of radon and thoron concentrations in the household dwellings. The presence of radioactive gases in the environment is mainly due to the...  相似文献   

9.
Effect of selective logging on vascular epiphyte diversity was investigated in a moist lowland forest of Eastern Himalaya. Three epiphytic groups viz. orchids, pteridophytes and non-orchid angiosperm epiphytes were specifically studied in closed, selectively logged and in unlogged forests with treefall gaps. Logging reduced the structural complexity of the forests and altered their microclimate. With logging, there was a general decline in richness and abundance of epiphytes except orchids. The abundance and species composition of pteridophytes and non-orchid angiosperm epiphytes were related to microclimate and substrate features while their richness were correlated only with canopy cover. In contrast, orchid species composition was related to forest structure. A combination of management strategies is required for conservation of all epiphyte groups. A mosaic of logged and unlogged forest patches with undisturbed forests in proximity would maintain the diversity of pteridophytes and other angiosperms. However, for full representation of orchids, it is necessary to maintain the structural diversity of the tree forms.  相似文献   

10.
Rice (Oryza sativa L.) is one of the three major food crops of the world and India is the largest rice growing country accounting for about one-third of the world average under the crop. Rice is being cultivated in Northern India since ca 2000 BC as evident from archaeological studies. A total of 103 traditional varieties of rice collected from interior parts, during the study period. The present study was designed with the aim to document the rice diversity and its socio-economic and cultural importance for local farming communities of Garhwal Himalaya in Central Himalayan Region. For collection of information 324 households from 116 villages in the study area were sampled. The study revealed different agro-eco-niches of the study area, traditional processing pathways, socio-economic and cultural development, diversity available, factors responsible for erosion/replacement of diversity, aesthetic values and specialized food quality of local rice varieties etc. The number of rice varieties grown and available for cultivation in ten valleys of Garhwal Himalaya were documented so as these can be utilized and conserved for research and development in the future.  相似文献   

11.
Genetic Resources and Crop Evolution - The collection and characterization of apricot germplasm is an important step for its utilization, conservation, and breeding programs. In the present study,...  相似文献   

12.
Abstract

Although lead in gasoline represents only 2.2% of total global lead use, this fuel remains by far the single largest source of this heavy metal in urban areas. In developing countries like India approximately 90% of all lead emissions into the atmosphere are due to the use of leaded gasoline. In many countries in Southeast Asia, unleaded gasoline is scarce, and the maximum allowed lead content might reach or exceed 0.8 ppm per liter. Emissions from the metallurgical operations and the waste incineration are also responsible for the rising levels of lead in the environment. Battery recycling, lead‐glazed pottery, and lead pigments industries are other sources of lead in the environment. In the present work, lead pollution in soil samples from Raipur (capital city) and Bhilai, Chhattisgarh State, India, has been investigated. The lead concentration in the surface soil of Raipur and Bhilai was found in the range of 7.2–84.0 and 9.5–79.7 ppm, respectively. The seasonal and temporal variations in the concentration of metal, its distribution pattern, and trend are discussed as well as the mobility, deposition, and sources of lead in the area. The enrichment factor of lead in the urban soil was found to be very high, depending on the nature of sources.  相似文献   

13.
Air pollution is a major contributor to several respiratory problems, it affects the whole population in general but children are more susceptible. Exposure to automobile exhaust is associated with increased respiratory symptoms and may impair lung function in children. In view of this, the study was conducted among the children of Delhi, the capital city of India, where ambient air quality was much above the National Ambient Air Quality Standards. The study was conducted in children aged 9–17 years. Pulmonary function test was carried out following the guideline of American Thoracic Society using a portable, electronic spirometer. Air quality data was collected from Central and State Pollution Control Boards. In addition, the level of particulate matter in indoor air was measured by portable laser photometer. Lung function was reduced in 43.5% schoolchildren of the urban area compared with 25.7% of control group. The urban children had increased prevalence of restrictive, obstructive, as well as combined type of lung functions deficits. Besides higher prevalence, the magnitude of lung function deficits was also much more in them. After controlling potential confounders like season, socioeconomic conditions and ETS, PM10 level in ambient air was found to be associated with restrictive (OR?=?1.35, 95% CI 1.07–1.58), obstructive (OR?=?1.45, 95% CI 1.16–1.82), and combined type of lung function deficits (OR?=?1.74, 95% CI 1.37–2.71) in children. Spearman's rank correlation test reaffirmed the association. The study confirms that the level of air pollution is affecting the children.  相似文献   

14.
Bull  K.R.  Achermann  B.  Bashkin  V.  Chrast  R.  Fenech  G.  Forsius  M.  Gregor  H.-D.  Guardans  R.  Haubmann  T.  Hayes  F.  Hettelingh  J.-P.  Johannessen  T.  Krzyzanowski  M.  Kucera  V.  Kvaeven  B.  Lorenz  M.  Lundin  L.  Mills  G.  Posch  M.  Skjelkvåle  B. L.  Ulstein  M. J. 《Water, air, and soil pollution》2001,130(1-4):119-130
For 20 years the Convention on Long-range Transboundary Air Pollution has worked to control air pollutant emissions in Europe and North America. Its Working Group on Effects (WGE) has been responsible for much of the underpinning science. The WGE's six International Cooperative Programmes (ICPs) on Waters, Natural Vegetation and Crops, Forests, Materials and Cultural Heritage, Integrated Monitoring, and Modelling and Mapping, together with a Joint Task Force on Human Health with WHO, quantify air pollution effects on the environment through monitoring, modelling and scientific review. Early work found evidence to support the need for decreases in emissions of sulphur and nitrogen pollutants. More recently, monitoring results and models have provided the scientific basis, e.g. critical loads and levels, for effects-based Protocols and for evaluating their effectiveness. ICP studies on trends show recovery from acidification effects in keeping with the fall in sulphur emissions. Steady-state models provide an indication of long-term improvements. Recent increased emphasis on developing dynamic models will enable better links between recovery rates and abatement strategies. The scientific network of the ICPs and the monitoring and modelling results have been key to the development of the Convention and are an essential component for its success in the future.  相似文献   

15.
16.
The aim of present study was to know about past cultivation of pseudocereals and millets in Kashmir province of Indian state of Jammu and Kashmir. These crops which were cultivated throughout Kashmir in plains as well as in hilly areas are buckwheat species, Fagopyrum esculentum and Fagopyrum tataricum; amaranth and minor millets, Setaria italica and Panicum miliaceum. In Kashmir these are now forgotten crops. Few plants of amaranth (Amaranthus caudatus) are still grown in almost every kitchen garden in Kashmir. The crop is however not cultivated commercially neither in Kashmir nor in Ladakh or Jammu provinces of the state. Our study has revealed that cultivation of all these crops has been abandoned some five or six decades back throughout Kashmir excepting in few farflung hilly areas in north Kashmir. Currently these crops are also cultivated in Ladakh, but here also their cultivation is dwindling rapidly. The reasons as to why farmers have abandoned these crops and are increasingly losing interest in these biological assets in the areas of their present cultivation have been discussed. There is a need to rescue these threatened crops which have many advantages besides, being nowadays categorized as quality health foods. During our survey in Ladakh province we have collected 30 germplasm accessions of these crops from various locations. These have been deposited in National Seed Gene Bank at NBPGR, New Delhi for conservation and evaluation. The improvement and revival of these lost crops has the potential to diversify agriculture, food system and income of the poor farmers and have the ability to ensure food security and livelihood of the people in this Himalayan state under future adverse climatic conditions.  相似文献   

17.
Water, Air, & Soil Pollution -  相似文献   

18.
汉江中下游土壤侵蚀及颗粒态非点源磷负荷研究   总被引:3,自引:0,他引:3  
以汉江中下游为研究区,考虑流域内部地理要素和时空过程的异质性,划分子流域作为基本的响应单元,利用2007年Landsat TM影像、DEM、土壤、气象和社会经济数据等,建立了流域基础数据库.在此基础上运用ArcGIS 9.2和Erdas 9.2计算得到流域降雨侵蚀力因子R,土壤可蚀性因子K,坡度坡长因子LS,经营管理因子C,水土保持因子P等.采用USLE和颗粒态非点源负荷经验方程,分别探讨了汉江中下游土壤侵蚀及非点源磷负荷的空间分布特征.结果表明:汉江中下游土壤的侵蚀模数为867.55 t/(km2·a),属于轻度侵蚀,但依然有5.69%的区域侵蚀模数大于2 500 t/(km2·a).流域内由于土壤侵蚀导致的颗粒态非点源磷负荷流失量达8 496.79 t/a,其中南河、唐白河、蛮河等支流的非点源流失状况最为严重,最高单位负荷量可达8.42 kg/(hm2·a).非点源负荷产生的关键源区主要分布在神农架林区、房县、保康等山地丘陵以及南阳盆地等农业生产区,因此增加植被郁闭度,控制坡地耕作,科学施肥,防止水土流失对于控制非点源污染有着重要意义.  相似文献   

19.
A bloom of Euglena was observed at the surface of Dal Lake, Kashmir, in the last week of June, 1991. The species exhibited a circadian colour change, from green at dawn to blood-red during the day and again green at dusk. The present new species is, therefore, named Euglena shafiqii. It is distinguished from the cogenus by the structure and occurrence of Z-tubules, chromatophores, nucleus shape and by a coloured pulsating structure at the posterior end. A stress induced transformation from an elongated egg to a round shape is also peculiar. The light absorption spectra of the pigment showed λ maxima at 416, 441, 467 and 485 nm. The red bloom was found in the part of the lake basins which receives waste effluents.  相似文献   

20.
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