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1.
Daily zenith scattered light intensity observations were carried out in the morning twilight hours using home-made UV-visible spectrometer over the tropical station Pune (18‡31′, 73‡51′) for the years 2000–2003. These observations are obtained in the spectral range 462–498 nm for the solar zenith angles (SZAs) varying from 87‡ to 91.5‡. An algorithm has been developed to retrieve vertical profiles of ozone (O3) and nitrogen dioxide (NO2) from ground-based measurements using the Chahine iteration method. This retrieval method has been checked using measured and recalculated slant column densities (SCDs) and they are found to be well matching. O3 and NO2 vertical profiles have been retrieved using a set of their air mass factors (AMFs) and SCDs measured over a range of 87–91.5‡ SZA during the morning. The vertical profiles obtained by this method are compared with Umkehr profiles and ozonesondes and they are found to be in good agreement. The bulk of the column density is found near layer 20–25 km. Daily total column densities (TCDs) of O3 and NO2 along with their stratospheric and tropospheric counterparts are derived using their vertical profiles for the period 2000–2003. The total column, stratospheric column and tropospheric column amounts of both trace gases are found to be maximum in summer and minimum in the winter season. Increasing trend is found in column density of NO2 in stratospheric, tropospheric and surface layers, but no trend is observed in O3 columns for above layers during the period 2000–2003  相似文献   

2.
The structure and kinematics of the ISM in an extended vicinity of the star WR 139 is analyzed using the results of original Hα interferometric observations together with radio and infrared data. A CO cavity with a size of up to 40′ has been detected around the star at velocities of V LSR ∼ 2.5–10 km/s; the cavity is bounded to the North by a shell radiating in the optical. Ionized hydrogen emits at the systematic velocities V LSR ∼ 6–14 km/s toward the CO cavity, and at V LSR ≃ 4–11 km/s toward the shell. High-velocity motions of ionized hydrogen inside the cavity testify to the probable expansion of gas that has been swept out by the stellar wind of WR 139 at velocities of up to 60–80 km/s.  相似文献   

3.
Summary We review recently obtained results about the velocity structure of the Somma-Vesuvius (Southern Italy) volcanic complex and present an interpretation of structural features, both at local and regional scale, and of the local seismicity. The local structure of Somma-Vesuvius is reviewed, referring to three depth ranges; i.e. shallow (0–5 km), intermediate (5–15 km) and deep (from 15 km to the upper mantle). The shallow velocity structure is inferred by the joint inversion of shot and local earthquake arrival time data. The main feature pointed out by this inversion is a high-velocity anomaly at the crater axis extending down to a depth of about 5 km. This anomaly can be explained with the presence of residual magma crystallised in the shallow conduits, which accumulated during the last eruptive cycles. The local seismicity is strongly clustered around this anomaly, due to the focusing effect of the rigidity contrast. The space-time seismicity pattern at Somma-Vesuvius is the result of the superposition of background seismicity, mainly due to gravitational instability of the volcanic edifice and to small external stress perturbations, with intense episodic earthquake swarms possibly due to magmatic or hydrothermal activity into the shallow system. The velocity structure in the 10–15 km depth range is characterized by the presence of a low-velocity layer, which has been independently confirmed by multi-channel seismic reflection data and P-Sv conversions from teleseismic waveforms. The study of the deep structure was performed by regional tomography with teleseisms; it confirmed the presence of a low-velocity anomaly underneath the volcano, which appears to have roots at greater depths. The regional structure between the Thyrrenian and the Adriatic sea has been inferred by tomographic inversion of teleseismic arrival times. The main result from this study which is very important for geodynamic interpretations is the first evidence for a continuous subducting slab under the Apennines, in an area where previous models hypothesized a slab window. Received March 3, 2000 revised version accepted July 4, 2001  相似文献   

4.
Coal fires are serious problem in Raniganj coalfield as it is the case for some of the other coalfields of India like Jharia coalfield. Earlier efforts were made to map the coal fires of this coal-field based on satellite observation. But the restricted distribution of major coal fires in the particular portion of the coalfield makes the basis for finding the geological control if responsible for coal fire distribution. In present study, night time thermal data of ASTER (Advance spaceborne thermal emission and reflection radiometer) is used to map the latest distribution (December, 2006) of coal fires in the Raniganj coalfield. Coal fire map shows that most significant zone affected by fire is at the north-western portion of the coalfield; where NE-trending open cast mines are affected by fire. This fire zone is associated with high grade coal of the Barakar Formation. Coal fires are also mapped in open cast pits of Jambad-Mangalpur area occurring over rocks of the Raniganj Formation. By integrating geological map and satellite-derived coal fire map of Raniganj coal field, it is observed that the coal fires detected by remote sensing study are spatially associated with intraformational faults. These faults may have played significant role in supplying oxygen to these coal-fires and allowing them to propagate down the depth along the trends of the faults.  相似文献   

5.
In the Damodar Valley Basin, coalfields containing coal bearing Barakar Formation are Raniganj, Jharia, Bokaro, Ramgarh, and Karanpura. The Barakar Formation is composed of conglomerate, sandstone, siltstone, shale, fireclay, and coal. The lower part of Barakar Formation represents a braided channel deposit, and also in few places glacio-fluvial deposit which changes to meandering channel system with the formation of some ox-bow lake, and cut-off channel in the middle part. In a few places deltaic/brackish water condition possibly existed along with this meandering channel system. In the upper part of Barakar Formation, marine signatures are more prominant. Marine signatures/influences have been reported from Barakar Formation of Ramgarh, South Karanpura, and West Bokaro coalfields on the basis of trace fossil assemblage, sedimentation character, and trace element content. Although, definite marine signatures have not been observed from Jharia, and Raniganj coalfields, high concentration of boron, vanadium, and chromium, and presence of skolithos, and thalassinoides burrows possibly suggest a brackish water condition. The upper part clearly suggest that the sediments were deposited in a geographic setting very close to the sea or at the edge of the sea possibly in a peritidal setting where storm activity played a vital role during sedimentation which in turn suggests the presence of a broad shallow sea (epeiric/epicontinental sea) that develop during times of high sea level. The sea water possibly entered from the northeastern side as vast seaways or as embayment through the Damodar Valley which acted as a channel.  相似文献   

6.
The objective of the present study was to delineate temporal and spatial changes in the coal fire and land use/cover within Bastacolla area of Jharia coal field. Studying this variation helped to decipher interconnection among the dynamics of the coal fire and concomitant changes in land use/cover. The detection of coal fires during a span of 14 years along with transitioning land use/cover was cost-effective and enabled planning for management of coal resources and environment. Landsat series of satellite data of 2002, 2009, 2013, and 2016 were processed for generating land surface temperature profiles vis-a-vis classified land use/cover of the study area. A single cut-off temperature was derived for mapping of coal fires using land surface temperature profile from 2002 to 2016. The satellite images were classified using support vector machines, and for depicting land use/cover change, post-classification change detection was done. Classification accuracy obtained was excellent with kappa coefficient ranging from 0.897 for classified image of 2002 to 0.799 for classified image of 2016. Results revealed that coal fires had shifted to the central west part of the area. Furthermore, pockets of coal fire from northern and eastern part of the study area have diminished. OB dumps and coal quarry/coal dump may be attributed towards the spatial change in coal fire while; OB dumps showed connotation with the highest temperature zones. Ground verifications for temperature profiles and coal fires were carried out using thermal camera which enunciated good agreement with results.  相似文献   

7.
Assessing pollutions of soil and plant by municipal waste dump   总被引：1，自引：0，他引：1  
Research is few in the literature regarding the investigation and assessment of pollutions of soil and plant by municipal waste dumps. Based upon previous work in seven waste dumping sites (nonsanitary landfills) in Beijing, Shanghai and Shijiazhuang, this study expounds the investigation and assessment method and report major pollutants. Using relative background values, this study assesses soil pollution degree in the seven dumping sites. Preliminary conclusions are: (1) pollution degrees are moderate or heavy; (2) pollution distance by domestic waste that is dumped on a plane ground is 85 m; (3) the horizontal transport distance of pollutants might be up to 120 m if waste leachates are directly connected with water in saturated soils; (4) vertical transport depth is about 3 m in unsaturated silty clayey soils. Furthermore, using relative background values and hygiene standards of food and vegetable this study assesses the pollutions of different parts of reed, sorghum, watermelon and sweet-melon. It is found: (1) in comparison with the relative background values in a large distance to the waste dumping sites, domestic wastes have polluted the roots and stems of reed and sorghum, whereas fine coal ash has polluted the leaves, rattans and fruits of watermelon and sweet-melon; (2) domestic wastes and fine coal ash have heavily polluted the edible parts of sorghum, water melon and sweet-melon. As, Hg, Pb and F have far exceeded standard values, e.g., Hg has exceeded the standard value by up to 650–1,700 times and Cd by 120–275 times, and the comprehensive pollution index is up to 192.9–369.7; (3) the polluted sorghum, watermelon and sweet-melon are inedible.  相似文献   

8.
A long mining history and unscientific exploitation of Jharia coalfield caused many environmental problems including water resource depletion and contamination. A geochemical study of mine water in the Jharia coalfield has been undertaken to assess its quality and suitability for domestic, industrial and irrigation uses. For this purpose, 92 mine water samples collected from different mining areas of Jharia coalfield were analysed for pH, electrical conductivity (EC), major cations (Ca2+, Mg2+, Na+, K+), anions (F−, Cl−, HCO3 −, SO4 2−, NO3 −), dissolved silica (H4SiO4) and trace metals. The pH of the analysed mine water samples varied from 6.2 to 8.6, indicating mildly acidic to alkaline nature. Concentration of TDS varied from 437 to 1,593 mg L−1 and spatial differences in TDS values reflect the variation in lithology, surface activities and hydrological regime prevailing in the region. SO4 2− and HCO3 − are dominant in the anion and Mg2+ and Ca2+ in the cation chemistry of mine water. High concentrations of SO4 2− in the mine water of the area are attributed to the oxidative weathering of pyrites. Ca–Mg–SO4 and Ca–Mg–HCO3 are the dominant hydrochemical facies. The drinking water quality assessment indicates that number of mine water samples have high TDS, total hardness and SO4 2− concentrations and needs treatment before its utilization. Concentrations of some trace metals (Fe, Mn, Ni, Pb) were also found to be above the desirable levels recommended for drinking water. The mine water is good to permissible quality and suitable for irrigation in most cases. However, higher salinity, residual sodium carbonate and Mg-ratio restrict its suitability for irrigation at some sites.  相似文献   

9.
The deep crustal structure of eastern Dharwar craton has been investigated through τ-p extremal inversion of P-wave travel times from a network of seismographs recording quarry blasts. Travel times have been observed in the distance range 30–250 km in a laterally homogeneous lithospheric segment Main features of the inferred velocity-depth relationship include: (a) 29 km thick combined upper and middle crust velocity varying from 6 km/s to 7 km/s, with no observable velocity discontinuity in this depth range; (b) a lower crust (∼ 29–41 km) with velocity increasing from 7.0 to 7.3 km/s; (c) an average upper mantle velocity of 8.1 km/s; and (d) presence of a 12 km thick high velocity crustal layer (7.4 – 7.8 km/s) in the depth range 41–53 km, with a distinct velocity gradient marking a velocity increase of 0.4 km/s. The anomalous 53 km thick crust is viewed as a consequence of magmatic underplating at the base of the crust in the process of cratonization of the eastern Dharwar craton during late Archaean. The underplated material reflects here with the velocity of 7–3 to 7–8 km/s below the depth of 40 km. Our proposition of magmatic underplating is also supported by the presence of large scale I-granitoid, a product of partial melting of the upper mantle material.  相似文献   

10.
A rocket-borne solar middle ultraviolet photometer has been developed at the Physical Research Laboratory, Ahmedabad for the measurement of ozone concentrations at stratospheric and mesospheric heights. The instrument has now been flown successfully several times from thumba and ozone concentrations determined over an altitude range of 15 to 80 km. This paper describes the instrumentation, data analysis technique as well as the laboratory calibration procedures. Also presented are the results from four successful rocket experiments conducted during equinoctial months under an Indo-USSR collaborative programme for strato-mesospheric studies. The results show that at Thumba peak ozone concentrations vary between 2·2 and 3·1×1012 molecules per cc and the peak altitude varies from 25 to 29 km from flight to flight. In the altitude region above about 40 km the ozone concentrations over Thumba are lower than the standard mid-latitude model values, by a factor lying between 1·5 and 2·5.  相似文献   

11.
Using the results of our Hα interferometric observations and observational data on the 21 cm and CO lines, we have analyzed the structure and kinematics of the interstellar medium in the extended vicinity of the star WR 137 and the supernova remnants CTB 87 and G73.9+0.9. A shell structure with a radius of up to 40′ observable in optical lines has been discovered around WR 137. The high-velocity motions of ionized hydrogen inside this shell can be interpreted as expansion of the gas swept out by the wind of WR 137 at velocities of up to 60 km/s. The ionized hydrogen near WR 137 emits at the systematic velocity V LSR ∼ 6–18 km/s. The expansion ofG73.9+0.9 at a velocity of up to 55 km/s has been confirmed. The systematic velocities of the ionized hydrogen toward this supernova remnant are V LSR ≃ −14…+14 km/s. An HI shell around G73.9+0.9 has been detected at velocities V LSR≃−14…−8 km/s. A very faint optical shell of CTB 87 with a size of about 20′ has also been detected. Evidence that CTB 87 is located in the Cygnus Arm is presented.  相似文献   

12.
Acid mine drainage (AMD) is a common pollution in mining areas due to the oxidation of pyrite and associated sulfide minerals at mines, tailings and mine dumps. Elevated metals (Fe, Mn, Al) and metalloids (As, Hg) in AMD would deteriorate the local aquatic environment and influence the water supply. A carbonate basin with deposits of high-arsenic coal in Xingren County, southwestern China, was chosen to study the behavior of As and other chemical constituents along a river receiving AMD. Heavy metals (Fe, Mn) and major ions such as (Ca2+, Mg2+, Cl−, SO4 2−) in surface water, and As in sediment and surface water were analyzed. It was found that high concentrations of SO4 2− (1,324–7,560 mg/L) and Fe (369–1,472 mg/L) in surface water were mainly controlled by the interactions between water and rocks such as the oxidation of pyrite in the local coal seams, precipitation and adsorption of iron minerals. Although ubiquitous carbonate minerals in the bedrock and the riverbeds, low pH (<3) water was maintained until 2 km downstream from the AMD source due to the Fe(hydro)oxide minerals coating on the surface of carbonate minerals to restrain the neutralization of acidic water. Moreover, the formation of Fe(hydro)oxide precipitations absorbed As was dominated the attenuation of As from water to sediment. Whereas, the dilution also played an important role in decrease of As in river water.  相似文献   

13.
Accurate prediction of in-situ stress directions plays a key role in any Coal Bed Methane (CBM) exploration and exploitation project in order to estimate the production potential of the CBM reservoirs. Permeability is one of the most important factors for determination of CBM productivity. The coal seams in Jharia coalfield generally show low permeability in the range of 0.5 md to 3 md. To estimate the in-situ stress direction in the study area, an attempt has been made to undertake the cleat orientation mapping of four regional coal seams of two underground coal mines located at south-eastern part of Jharia coalfield, India. Cleat orientation mapping is critical to determine the maximum principal compressive horizontal stress (SH) direction for CBM exploration and exploitation, which in turn controls the direction of maximum gas or water flow though coal beds. From the field study it is found that the average face and butt cleat azimuths are towards N15°W and N75°E respectively. Average permeability of the four above-mentioned major coal seams has been calculated from well logs of nine CBM wells distributing over an area of 7.5 km2, adjacent to the underground mines. The cleat orientations are congruous with the regional lineament pattern and fits well with the average permeability contour map of the study area to infer the orientation of in-situ maximum horizontal stress. Goodness of fit for the exponential regressions between vertical stress and permeability for individual coal seams varies between 0.6 and 0.84. The cleat orientation is further validated from the previous fracture analysis using FMI well log in Parbatpur area located southern part of the Jharia coalfield. The major coal seams under the study area exhibit directional permeability, with the maximum permeability, oriented parallel to the direction of face cleat orientation.  相似文献   

14.
Summary ?The NW–SE-trending Yulong porphyry Cu–Mo ore belt, situated in the Sanjiang0 area of eastern Tibet, is approximately 400 km long and 35 to 70 km wide. Complex tectonic and magmatic processes during the Himalayan epoch have given rise to favorable conditions for porphyry-type Cu–Mo mineralization. Porphyry masses of the Himalayan epoch in the Yulong ore belt are distributed in groups along regional NW–SE striking tectonic lineaments. They were emplaced mainly into Triassic and Lower Permian sedimentary-volcanic rocks. K–Ar und U–Pb isotopic datings give an intrusion age range of 57–26 Ma. The porphyries are mainly of biotite monzogranitic and biotite syenogranitic compositions. Geological and geochemical data indicate that the various porphyritic intrusions in the belt had a common or similar magma source, are metaluminous to peraluminous, Nb–Y–Ba-depleted, I-type granitoids, and belong to the high-K calc-alkaline series. Within the Yulong subvolcanic belt a number of porphyry stocks bear typical porphyry type Cu–Mo alteration and mineralization. The most prominent porphyry Co–Mo deposits include Yulong, Malasongduo, Duoxiasongduo, Mangzong and Zhanaga, of which Yulong is one of the largest porphyry Cu (Mo) deposits in China with approximately 8 × 106 tons of contained Cu metal. Hydrothermal alteration at Yulong developed around a biotite–monzogranitic porphyry stock that was emplaced within Upper Triassic limestone, siltstone and mudstone. The earliest alteration was due to the effects of contact metamorphism of the country rocks and alkali metasomatism (potassic alteration) within and around the porphyry body. The alteration of this stage was accompanied by a small amount of disseminated and veinlet Cu–Mo sulfide mineralization. Later alteration–mineralization zones form more or less concentric shells around the potassic zone, around which are distributed a phyllic or quartz–sericite–pyrite zone, a silicification and argillic zone, and a propylitic zone. Fluid inclusion data indicate that three types of fluids were involved in the alteration–mineralization processes: (1) early high temperature (660–420 °C) and high salinity (30–51 wt% NaCl equiv) fluids responsible for the potassic alteration and the earliest disseminated and/or veinlet Cu–Mo sulfide mineralization; (2) intermediate unmixed fluids corresponding to phyllic alteration and most Cu–Mo sulfide mineralization, with salinities of 30–50 wt% NaCl equiv and homogenization temperatures of 460–280 °C; and (3) late low to moderate temperature (300–160 °C) and low salinity (6–13 wt% NaCl equiv) fluids responsible for argillic and propylitic alteration. Hydrogen and oxygen isotopic studies show that the early hydrothermal fluids are of magmatic origin and were succeeded by increasing amounts of meteoric-derived convective waters. Sulfur isotopes also indicate a magmatic source for the sulfur in the early sulfide mineralization, with the increasing addition of sedimentary sulfur outward from the porphyry stock. Received August 29, 2001; revised version accepted May 1, 2002 Published online: November 29, 2002  相似文献   

15.
This article provides an overview of the various satellite instruments, which have been used to observe stratospheric ozone and other chemical compounds playing a key role in stratospheric chemistry. It describes the various instruments that have been launched since the late 1970s for the measurement of total ozone column and ozone vertical profile, as well as the major satellite missions designed for the study of stratospheric chemistry. Since the discovery of the ozone hole in the early 1980s, spatial ozone measurements have been widely used to evaluate and quantify the spatial extension of polar ozone depletion and global ozone decreasing trends as a function of latitude and height. Validation and evaluation of satellite ozone data have been the subject of intense scientific activity, which was reported in the various ozone assessments of the state of the ozone layer published after the signature of the Montreal protocol. Major results, based on satellite observations for the study of ozone depletion at the global scale and chemical polar ozone loss, are provided. The use of satellite observations for the validation of chemistry climate models that simulate the recovery of the ozone layer and in data assimilation is also described.  相似文献   

16.
《Comptes Rendus Geoscience》2018,350(7):368-375
Thanks to the Montreal Protocol, the stratospheric concentrations of ozone-depleting chlorine and bromine have been declining since their peak in the late 1990s. Global ozone has responded: The substantial ozone decline observed since the 1960s ended in the late 1990s. Since then, ozone levels have remained low, but have not declined further. Now general ozone increases and a slow recovery of the ozone layer is expected. The clearest signs of increasing ozone, so far, are seen in the upper stratosphere and for total ozone columns above Antarctica in spring. These two regions had also seen the largest ozone depletions in the past. Total column ozone at most latitudes, however, does not show clear increases yet. This is not unexpected, because the removal of chlorine and bromine from the stratosphere is three to four times slower than their previous increase. Detecting significant increases in total column ozone, therefore, will require much more time than the detection of its previous decline. The search is complicated by variations in ozone that are not caused by declining chlorine or bromine, but are due, e.g., to transport changes in the global Brewer–Dobson circulation. Also, very accurate observations are necessary to detect the expected small increases. Nevertheless, observations and model simulations indicate that the stratosphere is on the path to ozone recovery. This recovery process will take many decades. As chlorine and bromine decline, other factors will become more important. These include climate change and its effects on stratospheric temperatures, changes in the Brewer–Dobson circulation (both due to increasing CO2), increasing emissions of trace gases like N2O, CH4, possibly large future increases of short-lived substances (like CCl2H2) from both natural and anthropogenic sources, and changes in tropospheric ozone.  相似文献   

17.
The Hamamboğazi spa in western Turkey was built around natural hot springs with discharge temperatures in the range of 30–54°C; the waters have near neutral pH values of 6.50–7.10 and a TDS content between 2,694 and 2,982 mg/l. Thermal water with a temperature of 47.5–73°C has been produced at 325 l/s from five wells since 1994, causing some springs to go dry. A management plan is required in the study area to maximize the benefits of this resource, for which currently proposed direct uses include heating in the district and greenhouses, as well as balneology in new spas in the area. The best use for the water from each spring or well will depend on its temperature, chemistry and location. The thermal waters are mixed Na–Mg–HCO3–SO4 fluids that contain a significant amount of CO2 gas. The chemical geothermometers applied to the Hamamboğazi thermal waters yield a maximum reservoir temperature of 130°C. Isotope results (18O, 2H, 3H) indicate that the thermal waters have a meteoric origin: rainwater percolates downward along fractures and faults, is heated at depth, and then rises to the surface along fractures and faults that act as a hydrothermal conduit. The basement around the Banaz Hamamboğazi resort is comprised of Paleozoic metamorphic schist and marbles exposed 8 km south and 15 km north of Banaz. Mesozoic marble, limestone and ophiolitic complex are observed a few km west and in the northern part of Banaz. These units were cut at a depth of 350–480 m in boreholes drilled in the area. Overlying lacustrine deposits are composed of fine clastic units that alternate with gypsum, tuff and tuffites of 200–350 m thickness. The marble and limestones form the thermal water aquifer, while lacustrine deposits form the impermeable cap.  相似文献   

18.
The Piedmont Zone of the Indo-Gangetic Plain contains numerous, laterally coalescing small alluvial fans. The Latest Pleistocene–Holocene 30 km long Gaula Fan can be divided into gravelly proximal fan (0–14 km down-stream), gravel-sand rich mid fan (14–22 km) and sand–mud dominated distal fan (22–30 km). The fan succession is composed of two fan expansion cycles A and B. Separated by an undulatory erosional contact of regional extent, cycle A is characterized by river borne clast-supported gravelly deposits, and the overlying fan expansion cycle B by matrix-supported gravely debris flows. The main process behind fan development has been lateral migration of channels over the fan surface probably due to rapid sedimentation caused by increased sediment supply, and the fluctuating water budget in response to changing climate. The water laid expansion cycle A represents a humid phase. The debris flow deposits of expansion cycle B suggest a dry phase. Approximately between 8 and 3 Ka, cycle B also indicates a phase of tectonic instability in the Siwalik Hills forming the mountain front. The tectonic activity caused incision of rivers into the fan surface, and in turn resulted in reduced fan-building activity. At present the fan surface is accreting by sheet flow processes.  相似文献   

19.
The present study deals with the characterization of subsurface coal fires of East Basuria colliery in Jharia coal field, India using tilt derivative and downward continuation of magnetic data. Magnetic data processing methods such as diurnal correction, noise removal, reduction to pole, tilt derivative and downward continuation have been used to process the data and for the interpretation of results on the basis of magnetic properties of overlying materials which change with the temperature variation above or below the Curie temperature. Most of the magnetic anomalies are associated with coal fire and non-coal fire regions which are correlated with tilt-derivative anomaly and corresponding downward-continued anomaly at different depths. The subsequent surface and subsurface characteristics are explained with good agreement. Approximate source depth of principal anomaly inferred from tilt derivatives method are corroborated with multi-seam occurrences, mine working levels and surface manifestation which are also correlated well with 3D model of downward continued anomaly distribution.  相似文献   

20.
During very considerable progress in industry and industrial centres development in late 20th and early 21st century, air pollution has become one of the most significant problems of mega cities. Thus, air pollution survey to exert abatement methods has a very important role. Various methods are available for air pollution monitoring which are very costly. Air pollution monitoring by susceptible plants as biological indicators are not only economic but also simple. In this paper, vast studies were done on the plants of around each Queensland Environmental Protection Agency (QEPA) monitoring sites. Around these sites susceptible plants to air pollution were neither available nor exist in all monitoring sites. Therefore, it seemed the best method is the portable exposure benches application with automatic watering system in five sites among all studied locations. In this research different varieties of tobacco like Weather fleck, Bel-B, Bel-W3, Dynes, ZZ100 were used to measure the impact of ozone as a pollutant on them. Parsley cv. Frizz and Leek cv. Vertina were selected as nitogen oxides indicators. In general, the above-mentioned plants were exposed to the ambient air in five sites around Brisbane from April 1997 to May 1998. The susceptible variety leaves of Bel-W3 showed injuries just in two sites. The reason for this is the high level of ozone and the effects of climatic factors in production and dispersion of it during the experiments. The survey results represent that ozone with elevated concentrations is available as far as 30km radius from Brisbane city centre. Within this area only the most susceptible plants’ leaves would be liable to suffer injury.  相似文献   

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