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1.
Aulinger A Prange A Niedergesäss R Schmolke S Einax JW 《Journal of environmental monitoring : JEM》2002,4(6):942-949
Sediments and suspended particulate matter taken from about 100 sampling sites along the River Elbe from the source to the mouth during the period 1992 and 1998 have been analyzed for the concentrations of more than 60 elements in each sample. The analytical data were subsequently processed by means of multivariate statistics in order to characterize the charge of the River Elbe with inorganic pollutants to elucidate pollution trends. Using factor analysis 18 elements were found to be enriched by human activities. By means of cluster analysis--using the 18 anthropogenically influenced elements as variables--the sampling sites were aggregated into groups having similar element distributions. Thus, the entire stretch of the River Elbe was divided into three sections of characteristic elemental pollution. Finally, the trends in anthropogenic pollution within the characteristic regions since the early nineties were assessed. It turned out that most of the anthropogenically influenced elements showed a decrease in the upper and middle parts of the river, whereas no decrease could be verified in the estuary region. 相似文献
2.
Residues of organochlorine pesticides in water and suspended particulate matter from the Yangtze River catchment of Wuhan, China 总被引:6,自引:0,他引:6
The residues of 13 organochlorine pesticides (OCPs) in surface water and HCHs and DDTs in suspended particulate matter (SPM)
from rivers and lakes in Yangtze River catchment of Wuhan, China, were investigated. The concentration of total OCPs in surface
water varied from 1.01 to 46.49 ng l−1 (mean 10.55 ng l−1). The levels of total HCHs (ΣHCH) and total DDTs (ΣDDT) in surface water were in the range of 0.55–28.07 ng l−1 and lower than detection limit to 16.71 ng l−1, respectively, which was lower than Chinese standards on the whole. For OCPs residues in SPM, the mean levels varying from
0.20 to 34.72 ng l−1 and 0.46 to 2.72 ng l−1 for ΣHCH and ΣDDT, respectively, which ranked the relatively higher levels among Chinese studied rivers. Results from this
investigation showed that previous excessive usage of technical OCPs was the main reason for the residues of HCHs and DDTs
both in surface water and SPM, although some new sources were likely to occurred in the region. Apart from the OCPs in SPM
originated from upstream in flood season, one of the important sources of OCP residues both in water and SPM in Yangtze River
was supposed to be the inputs of its tributaries. Additionally, in situ water-SPM phase distributions of OCPs indicated that
HCHs tended totransport with water as well as DDTs was prone to combine with SPM in Yangtze River catchment of Wuhan. 相似文献
3.
Melisa Daiana Fernández-Severini Mónica Susana Hoffmeyer Jorge Eduardo Marcovecchio 《Environmental monitoring and assessment》2013,185(2):1495-1513
The present work includes part of the first studies of metals concentrations in the zooplankton from a heavily industrialized estuary of Argentina, the Bahía Blanca estuary. Cd, Cu, and Pb concentrations in the zooplankton (macro- and mesozooplankton) and the suspended particulate matter were measured at stations with different degree of pollution. Physicochemical variables and zooplankton composition and abundance were also analyzed. Thus, the aim of the present work was to analyze the spatial and temporal distribution of heavy metals in these two different fractions, and the possible relation among them due to their importance in the biogeochemical cycles of marine environments. Samplings were carried out during a year, from March 2005 to April 2006, every 2 months, at stations located near chemical and petrochemical industries, stations far from these points and one station in an intermediate location. In the mesozooplankton, the mean concentrations of Cd, Cu, and Pb were 3.63?±?1.46, 34.46?±?5.40, and 11.54?±?3.04 μg?g?1 dry weight (d.w.) respectively, while in the macrozooplankton, 3.20?±?2.28, 21.86?±?4.79, and 8.36?±?1.85 μg?g?1 d.w. On the other hand, particulate Cd, Cu, and Pb presented a mean concentration of 3.33?±?1.22, 12.75?±?2.67, and 12.53?±?3.20 μg?g?1 d.w., respectively. Metals’ levels in both the SPM and zooplankton fluctuated throughout the study time and were relatively high in the particulate phase especially for Cu and Pb. Moreover, zooplankton accumulated important concentrations of the three metals. The sources of them are probably the discharges of the industries and domestic sewages located near the estuary. 相似文献
4.
M. V. Maya Melena A. Soares Rajesh Agnihotri A. K. Pratihary Supriya Karapurkar Hema Naik S. W. A. Naqvi 《Environmental monitoring and assessment》2011,175(1-4):501-517
Chemical and isotopic (??13C and ??15N) investigation of the Mandovi estuary along the Indian west coast affected strongly by the seasonal monsoon cycle was carried out. The Mandovi estuary is a major waterway for Goa and extensively used for transportation of iron and manganese ore. In addition, with large population centers as well as agricultural fields located on its shores, the estuary is assumed to have been influenced by human activities. Measurements of chemical and isotopic parameters made in the lower part of the estuary during the southwest (SW) monsoon and post-monsoon seasons reveal distinct changes, and it is observed that despite considerable enrichment of macronutrients during the SW monsoon, productivity of the estuary (phytoplankton biomass), as inferred from the chlorophyll-a content, is not as high as expected. This is due to occurrences of high turbidity and cloud cover that limits photosynthetic productivity. The isotopic characterization (C and N isotopes) of suspended organic matter produced/transported during the monsoon and post-monsoon seasons of year 2007 provides a baseline dataset for future isotopic studies in such type of tropical estuaries. 相似文献
5.
Yongqiang Yang Zhuli Liu Fanrong Chen Shijun Wu Ling Zhang Mingliang Kang Jie Li 《Environmental monitoring and assessment》2014,186(12):8089-8107
Twenty-four major and trace elements and the mineralogical composition of four sediment cores along the Pearl River and estuary were analyzed using ICP-AES, ICP-MS, and X-ray diffraction (XRD) to evaluate contamination levels. The dominant minerals were quartz, kaolinite, and illite, followed by montmorillonite and feldspars, while small amounts of halite and calcite were also observed in a few samples. Cluster analysis (CA) and principal component analysis (PCA) were performed to identify the element sources. The highest metal concentrations were found at Huangpu, primarily due to wastewater treatment plant discharge and/or the surreptitious dumping of sludge, and these data differed from those of other sources. Excluding the data from Huangpu, the PCA showed that most elements could be considered as lithogenic; few elements are the combination of lithogenic and anthropogenic sources. An antagonistic relationship between the anthropogenic source metals (K, Ba, Zn, Pb, Cd, Ag, Tl, and U) and marine source metals (Na, Mg, Ti, V, and Ca) was observed. The resulting normalized Al enrichment factor (EF) indicated very high or significant pollution of Cd, Ag, Cu, Zn, Mo, and Pb at Huangpu, which may cause serious environmental effects. Conflicting results between the PCA and EF can be attributed to the background values used, indicating that background values must be selected carefully. 相似文献
6.
Retrieval of total suspended matter (TSM) and chlorophyll-a (Chl-a) concentration from remote-sensing data for drinking water resources 总被引:1,自引:0,他引:1
Song K Li L Wang Z Liu D Zhang B Xu J Du J Li L Li S Wang Y 《Environmental monitoring and assessment》2012,184(3):1449-1470
The concentrations of chlorophyll-a (Chl-a) and total suspended matter (TSM) are major water quality parameters that can be retrieved using remotely sensed data. Water
sampling works were conducted on 15 July 2007 and 13 September 2008 concurrent with the Indian Remote-Sensing Satellite (IRS-P6)
overpass of the Shitoukoumen Reservoir. Both empirical regression and back-propagation artificial neural network (ANN) models
were established to estimate Chl-a and TSM concentration with both in situ and satellite-received radiances signals. It was found that empirical models performed
well on the TSM concentration estimation with better accuracy (R
2 = 0.94, 0.91) than their performance on Chl-a concentration (R
2 = 0.62, 0.75) with IRS-P6 imagery data, and the models accuracy marginally improved with in situ spectra data. Our results
indicated that the ANN model performed better for both Chl-a (R
2 = 0.91, 0.82) and TSM (R
2 = 0.98, 0.94) concentration estimation through in situ collected spectra; the same trend followed for IRS-P6 imagery data
(R
2 = 0.75 and 0.90 for Chl-a; R
2 = 0.97 and 0.95 for TSM). The relative root mean square errors (RMSEs) from the empirical model for TSM (Chl-a) were less than 15% (respectively 27.2%) with both in situ and IRS-P6 imagery data, while the RMSEs were less than 7.5% (respectively
18.4%) from the ANN model. Future work still needs to be undertaken to derive the dynamic characteristic of Shitoukoumen Reservoir
water quality with remotely sensed IRS-P6 or Landsat-TM data. The algorithms developed in this study will also need to be
tested and refined with more imagery data acquisitions combined with in situ spectra data. 相似文献
7.
Some physicochemical parameters were determined for thirty field water samples collected from different water channels in the Pearl River Delta Economic Zone river system. The analytical results were compared with the environmental quality standards for surface water. Using the SPSS software, statistical analyses were performed to determine the main pollutants of the river water. The main purpose of the present research is to investigate the river water quality and to determine the main pollutants and pollution sources. Furthermore, the research provides some approaches for protecting and improving river water quality. The results indicate that the predominant pollutants are ammonium, phosphorus, and organic compounds. The wastewater discharged from households in urban and rural areas, industrial facilities, and non-point sources from agricultural areas are the main sources of pollution in river water in the Pearl River Delta Economic Zone. 相似文献
8.
Peng G Wang X Wu Z Wang Z Yang L Zhong L Chen D 《Journal of environmental monitoring : JEM》2011,13(7):1927-1934
Two-year monitoring data (2006 and 2009), collected at the sub-urban site (WQS) and the background site (TH), were used to study the characteristics of Particulate Matter (PM) pollution in the Pearl River Delta region, China. Similar levels of PM(2.5) concentration measured at both sites seem to confirm that the fine particles have emerged as a major regional pollution issue. The seasonal variation of PM(2.5) concentration is associated with the regional monsoon circulations while the diurnal variation is related to land-sea breeze, traffic emissions and boundary layer development. Negative correlation was found in PM(2.5)-wind speed and PM(2.5)-humidity. Analysis of radiation, temperature and ozone suggests the existence of secondary aerosol formation. Transport effect may be another contributing factor to high PM pollution in the region, such as occasional long-distance dust intrusion and trans-boundary effects from upwind areas. 相似文献
9.
Yang Yanhong Sheng Guoying Fu Jimo Min Yushun 《Environmental monitoring and assessment》1997,44(1-3):569-575
Samples of river water and sewage water were analysed for ten PCB congeners, chlorobenzenes and chlorinated pesticides (BHCs and DDT) in three cities (Guangzhou, Shenzhen and Zhaoqing) in the Pearl River Delta, The results showed that the sewage water in Shengzhen had the highest concentration of total PCBs at about 10ng/L, and Dasha River (Shengzhen), the lowest at about 1.0ng/L. In general, the sewage waters in the three cities had higher concentrations of PCBs than river waters. Chlorobenzenes were investigated in the water samples. The total concentrations of chlorobenzenes ranged from 0.02~0.13g/L, the Dasha River had the highest level of chlorobenzenes, and the sewage water in the city of Zhaoqing had the next highest. The result may be related to the discharges from paper production factories nearby the sampling sections of the Dasha River (Shenzhen) and sewage water in Zhaoqing. The concentrations of organochlorinated pesticides (-BHC, -BHC, -BHC, DDT and DDE) changed little in all water samples except for the sewage water in Guangzhou. It seemed that these pesticides are more a residual signal than a direct discharge from point sources. 相似文献
10.
Joseph P. Essien Stephen I. Eduok Abass Abiola Olajire 《Environmental monitoring and assessment》2011,176(1-4):99-107
The distribution of polycyclic aromatic hydrocarbons (PAHs) in epipelic and benthic sediments from Iko River estuary mangrove ecosystem has been investigated. Total PAHs ranged from 6.10 to 35.27 mg/kg dry weight. Quantitative difference between the total PAHs in epipelic and benthic sediments showed that the benthic sediment known for higher capability to serve as sink for chemical pollutants accumulated less PAHs. This implies that PAHs in the epipelic sediment may plausibly be from industrial sources via runoff and/or of biogenic origin. A strong pyrolytic source fingerprint has been detected with slight influence of petrogenic sources. Total organic carbon normalized PAHs (sum of 16 PAHs, 59.7 to 372.4 mg/kg OC) were under (except for ES3 and BS3) the threshold effects concentrations (TEC, 290 mg/kg OC). Total PAHs in Iko River estuary sediments were in the range between ERL and ERM. 相似文献
11.
Ribeiro C Pardal MA Martinho F Margalho R Tiritan ME Rocha E Rocha MJ 《Environmental monitoring and assessment》2009,149(1-4):183-193
Recent studies in the Mondego River estuary demonstrated signs of pollution in the area, but the nature of the contamination remains unexplored. Because there seems to be any studies in that zone checking for the simultaneous presence of xenoestrogenic endocrine disrupting compounds, either of animal (estradiol and estrone), vegetal (daidzein, genistein and biochanin A), pharmaceutical (17alpha-ethynylestradiol) or industrial (bisphenol A, 4-octylphenol, 4-nonylphenol) origins, the main objective of this study was to investigate their presence, in every year season and at eight points along the estuarine gradient. For this propose, water samples (2 L) were collected in high and low tides, preconcentrated in the Oasis HLB cartridges and cleaned in silica cartridges before their analysis by HPLC-DAD and GC-MS. The current data showed the absence of contamination by animal or pharmaceutical estrogens and by alkylphenols, but demonstrated the presence of high levels of phytoestrogens (up to 1.1 mug/L) and of bisphenol A (up to 880.0 ng/L). Because these two chemicals existed in high environmental concentrations in the most upstream sampling station, and taking in account that these pollutants may additively contribute to endocrine disruption, namely on fish, it was concluded that at least this particularly area of the Mondego estuary deserves continuous monitoring programmes. 相似文献
12.
Kontas A 《Environmental monitoring and assessment》2012,184(5):2605-2616
The concentrations of trace metals (Cu, Zn, Mn, Ni, and Fe) from suspended particulate matter (SPM) and biota in Izmir Bay
(Eastern Aegean Sea) were studied in order to evaluate the environmental impact of the anthropogenic metals before building
of Wastewater Treatment Plant. SPM samples were collected in wet and dry periods from Izmir Bay. Metal concentrations in SPM
(Cu, 0.36–2.19; Mn, 0.07–11.3; Ni, 0.43–7.81; Zn, 7.33–269; Fe, 1.00–266 μgdm − 3) were comparable to those reported for other moderately polluted bays. Maximum metal concentrations in SPM were observed
during summer season. SPM metal concentrations displayed a clear spatial trend with values increasing with proximity to urban
centers. Cu and Zn concentrations in SPM were especially high in the inner bay. SPM were found to be contaminated by Zn. The
vertical profile of Mn, Zn, and Ni concentrations in SPM had a maximal value at the upper layer and decreased to minimal value
at the bottom layer of the inner bay in summer, in contrast to the observed pattern of Fe and Cu. Maximum Cu concentrations
were obtained in Penaeus kerathurus. Also, maximum Zn and Fe concentrations were found in Mytilus galloprovincialis. Relatively high Cu levels were found in Sardina pilcardus and Mullus barbatus than other fish species. Besides, Cu levels were lower in Diplodus annularis and Merluccius merluccius. Finally, metal levels in biota tissues were lower than the limits of European Dietary Standards and Guidelines. 相似文献
13.
为评估抗生素在珠三角地表水中的生态及健康风险,在石岐河布设20个监测点位,分别采集丰水期和枯水期样品,用固相萃取/超高效液相色谱-质谱法对4大类共49种抗生素进行检测。结果显示,在丰水期和枯水期样品中共检出抗生素30种,检出种类和抗生素总浓度都呈现出枯水期明显大于丰水期的现象。从总量上看,喹诺酮类是影响石岐河生态环境安全的主要抗生素类别。石岐河抗生素浓度在枯水期主要受污水处理设施出水的影响,在丰水期主要受沿岸养殖业排水的影响。采用风险熵法对生态风险进行评估,发现枯水期生态风险高于丰水期,头孢匹啉、克林霉素、诺氟沙星3种抗生素处于高生态风险级别,罗红霉素、磺胺二甲异恶唑和奥索利酸3种抗生素处于中等生态风险级别,另有4种抗生素处于低生态风险级别,应引起重视。采用健康风险评价模型对人群健康风险进行评价,发现石岐河抗生素致癌风险和非致癌风险皆处于可接受的健康风险范围内。 相似文献
14.
Persistent organic pollutants (POPs) such as organochlorine (OCl) insecticides and polychlorinated biphenyls (PCB), together with the new generation of organophosphorus (OP) insecticides, are of global concern, due to their widespread occurrence, persistence, bioaccumulation and hormone disruption potential. This paper represents an attempt to study the source and transportation of such pollutants in estuarine and coastal environments as an integrated ecosystem, by determining the levels of 18 OCl insecticides, 21 PCB congeners, and 17 OP insecticides in the Pearl River Estuary and South China Sea. The total concentrations varied from 126-1198 ng l(-1) for OCl insecticides, 33.38-1064 ng l(-1) for PCB congeners, and 4.44-6356 ng l(-1) for OP insecticides in the Pearl River Estuary. In comparison, their levels in the South China Sea were significantly lower, varying from 57.09-202 ng l(-1) for OCl insecticides, 21.72-144 ng l(-1) for PCBs, and 1.27-122 ng l(-1) for OP insecticides, respectively. The predominance of beta-HCH in HCHs, and DDE in DDTs in all water samples was clearly observed, suggesting beta-HCH and DDE's resistance to further degradation. The PCBs were dominated by those with 3-6 chlorines. The distribution characteristic of OP insecticides shows that five compounds (methamidophos, dimethoate, malathion, dichlorvos and omethoate) accounted for 56% and 72% of the total OP insecticide concentration. The relationship between pollutant concentrations and salinity in the estuary showed that they were all removed during the mixing process, therefore behaving non-conservatively. 相似文献
15.
利用GC-ECD方法测定了珠江三角洲城市群及高海拔地区表层土壤中的有机氯农药。有机氯农药变幅为2.4~78.7 ng/g,平均15.9 ng/g。最高值出现在江门。总HCHs变幅为ND~19.2 ng/g,平均2.91 ng/g, 最高值出现在佛山。总DDTs变幅为ND~74.6 ng/g,平均值为9.91 ng/g。最高值出现在东莞。六氯苯在佛山较高。灭蚁灵在深圳的污染较其它地区严重。总体来说,HCHs污染程度较低,但部分地区有林丹的使用;有些采样点DDTs的污染程度超过了国家土壤环境质量标准的一级自然背景值,且有些区域可能有非三氯杀螨醇的DDTs外源输入。 相似文献
16.
2009年3月对珠江广州大桥到海印桥段底栖动物群落结构进行调查。共采集6种底栖动物样品,其中霍夫水丝蚓为研究区域优势类群,密度和生物量相对丰度分别为96.3%和71.9%。海印桥底栖动物密度和生物量最大,分别为305280ind/m2和664.72g/m2;中大码头次之,分别为54144ind/m2和129.27g/m2;广州大桥最小,分别为43200ind/m2和93.87g/m2。底栖动物群落结构极为不均匀,广州大桥、中大码头和海印桥Shannon-Wiener多样性指数分别为0.34、0.27、0.14;Margalef多样性指数分别为0.32、0.19、0.11,均匀度指数0.19、0.20、0.13,物种丰度分别为6、4和3,属严重污染水平。对理化指标进行分析表明,溶解氧过低是生物多样性低的直接原因,控磷、除磷对降低水体营养水平,恢复生物多样性意义重大。 相似文献
17.
Ahmet Demirak Hanife Ayd?n Y?lmaz Feyyaz Keskin Yal??n ?ahin O?uz Akpolat 《Environmental monitoring and assessment》2012,184(12):7113-7124
The Bay of Gokova in Southeastern Aegean Sea (Turkey) is important by the potential of agricultural, municipal, and tourism activities. In addition, there is no industrial plant within the area in the Aegean Sea. Kad?n Creek (Azmak) and Ak?ap?nar Creek (Azmak) flowing into the inner Gokova Bay are one of the important factors in determining the character of the inner Gokova Bay. In this study, nine stations were selected in the inner Gokova Bay, Kad?n Creek, and Akcap?nar Creek. The concentrations of Cd, Cu, Fe, Pb, and Zn were measured in suspended particulate matter (SPM) and sediments. The samples of sediments and SPM were collected in between February 2008 and September 2008. The aim of the study is searching the change of concentrations of Cd, Cu, Fe, Pb, and Zn in suspended particulate matter and sediments in the inner Gokova bay, Kad?n Creek, and Ak?ap?nar Creek. It has been identified that the metal concentrations in the creeks are higher than the metal concentrations in the marine environment. It has also been observed that the concentrations of Pb, Cd, and Cu in summer season have been higher than in the winter season, but the concentrations of Fe and Zn have not shown a significant difference between in summer and winter seasons. The obtained results show that the some heavy metals are caused by the agricultural, municipal, and tourism activities operating in the coastal areas and terrestrial environment, and they are transported from the creeks to the Gokova Bay by suspended particulate matter. 相似文献
18.
The accelerated industrialization and urbanization in the last three decades around the Pearl River Delta within Guangdong Province in China have led to serious concerns about the impacts on the aquatic environment. In the present study, the genotoxicity of the sediments collected from the Pearl River was evaluated by micronucleus (MN) assay with Vicia faba root tip cells, and the 16 EPA priority polycyclic aromatic hydrocarbons (PAHs) and heavy metals (HMs, including Cr, Cu, As, Se, Cd, Hg, and Pb) in the sediments were determined respectively by GC-MS, inductively coupled plasma mass spectrometry, and inductively coupled plasma atomic emission spectrometry. The results showed that there were significant increases of MN frequencies observed in the sediment-exposed groups, compared with the negative group (P?0.05, P?0.01), indicating that the sediments clearly had genotoxicity to the V. faba root cells. The total concentrations of the priority PAHs (250-13,656 ng g(-1), dry weight) and HMs (As, 22,770-36,639 μg kg(-1); Cr, 39,333-133,343 μg kg(-1); Cu, 36,145-159,270 μg kg(-1); Pb, 51,210-166,642 μg kg(-1); Cd, 475.4-1,818.9 μg kg(-1); Hg, 59.9-460.8 μg kg(-1); and Se, 331.7-1,250.4 μg kg(-1), dry weight) were close to those obtained from other urbanized and industrialized areas, which have been considered moderately polluted. There was a clear positive correlation between MN potency and the molar concentrations of Hg and Pb in the sediments (Hg, r?=?0.94; Pb, r?=?0.91), suggesting that Hg and Pb were the most important factors that posed the sediments higher genotoxicity to V. faba root cells. Our results suggested that both biological and chemical approaches are necessary to be included in a battery of tests to assess the eco-environmental risks of sediments. 相似文献
19.
Cláudia Ribeiro Miguel Ângelo Pardal Maria Elizabeth Tiritan Eduardo Rocha Rui Miguel Margalho Maria João Rocha 《Environmental monitoring and assessment》2009,159(1-4):415-427
The important Portuguese Sado River estuary has never been investigated for the presence of potentially endocrine-disrupting chemicals (EDCs), such as natural estrogens (estradiol, estrone), pharmaceutical estrogens (17α-ethynylestradiol), phytoestrogens (daidzein, genistein and biochanin A), or industrial chemicals (4-octylphenol, 4-nonylphenol, and bisphenol A). Thus, the main objective of this study was to evaluate their presence at 13 sampling points distributed between both the industrial and the natural reserve areas of the estuary, zones 1 and 2, respectively. For that, water samples collected in summer and winter were processed by solid phase extraction and analyzed by high-performance liquid chromatography with photodiode array detection and gas chromatography–mass spectroscopy. Results showed that estrone, ethynylestradiol, all the aforementioned phytoestrogens as well as bisphenol A and 4-octylphenol were found in zone 1. In zone 2, neither estrogens nor 4-OP were found. However, in the same zone, daidzein (500 ng/L) and genistein (320 ng/L) attained their highest levels in summer, whereas biochanin A peaked in winter (170 ng/L). Furthermore, bisphenol A was also found in some areas of zone 2, but showed similar concentrations in both surveys (about 220 ng/L). This study demonstrated that the Sado River estuary had low EDCs levels, suggesting that the Sado’s high hydrodynamic activity may be involved in the dilution of local pollution. It was suggested that at the current levels of concentrations, all assayed EDCs are unlikely to individually cause endocrine disruption in local animals. However, under a continuous exposure scenario, an additive and/or synergistic action of the estrogenic chemicals load can not be excluded, and so, continuous monitoring is advisable. 相似文献
20.
Simulation of Wind Circulation and Pollutant Diffusion Over the Pearl River Delta Region 总被引:1,自引:0,他引:1
Li-Ping Zeng Wen-Shi Lin Qi Fan Ye-Rong Feng 《Environmental Modeling and Assessment》2012,17(5):539-553
Changes in urban surface areas and population growth have significantly affected the weather and environment. Emissions of nitrogen oxides are increasing in the Pearl River Delta region. Nitrogen compounds emitted by factories and motor vehicles are the major sources of nitric pollution. To study the impacts of urbanization and the relationship between pollutant diffusion and the atmospheric environment, the nonhydrostatic mesoscale forecast model MM5 (v3.73), which was developed by Penn State University and the National Center of Atmospheric Research, and a mass continuity equation for air pollutants, were used in this study. Two experiments were designed. One experiment (BE) applied horizontal grid resolutions of 27, 9, 3, and 1?km in four nested domains. The other experiment adopted new land-use data (in domain 4) directly retrieved from Landsat Thematic Mapper imagery to replace the 1980s data of the United States Geological Survey in BE. A 48-h simulation (from 0000?UTC on 21 October to 0000?UTC on 23 October 2008) was conducted, with the first 12?h being the spin-up time and the remaining 36?h being the effective simulation, so as to capture the diurnal features of the thermally induced winds associated with the land–sea breeze and urban heat island circulations. The different results obtained from the two tests for wind circulation and air pollution dispersion and transportation in the Pearl River Delta region were analyzed. The simulated results show that the both experiments can well simulate land–sea breeze circulation and remarkable land–sea breeze evolution, comparing with observation data. The height of the PBL had a significant diurnal cycle. The structure of the wind field can obviously impact the dispersion of the NO x in three dimensions. Nitrogen oxides mainly diffused along the dominant wind direction (east or southeast wind), therefore the majority of the pollutants accumulated in the northwest region of the fine domain in both simulation experiments. However, it induced the pollutants concentration in an irregular pattern due to the fine-resolution grid spaces and complicated inland wind field in the northwest area of the inner domain. Moreover, increasing the proportion of urban surface caused sensible heat flux increase, latent heat flux decrease and humility reducing relatively in the region of urban surface characteristics apparently. Urbanization will cause pollution accumulated severely over the urban surface. 相似文献