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91.
以珠三角典型灰霾天气为例谈资料分析方法   总被引:2,自引:0,他引:2  
分析处理复杂问题需要抓住主流,以珠三角地区发生的一次典型灰霾天气过程为例讨论了抽丝剥茧的资料分析方法.这次灰霾过程同期20日左右,中亚、蒙古国与我国北方发生了当年沙尘天气影响范围最广的一次强沙尘暴过程,冷空气前锋22日凌晨到达穗港地区,但穗港两地空气质量发生了相反的变化,香港空气质量急剧恶化,气溶胶浓度超过700μg/...  相似文献   
92.
The impact of large-scale urban development on land resources has long been debated by urban planners and designers. This study investigated the extent to which different urban characteristics are associated with land-cover change. The Yangtze River Delta region in China, forming one of the largest sprawling urban landscapes among the regions around the world, was chosen for the study area. Spatial analysis and multiple regression methods were applied to empirically investigate the pattern of resource sites lost to urban development in the area between the 1950s and 2017. The results showed that contrary to the widespread notion that large-sized cities are predominantly responsible for a region’s environmental degradation, city size was not a significant factor in determining the rate of resource loss. Large-sized cities gained their populations with far lesser impacts on land than small-sized cities and towns if normalized to the same number of populations. One explanation for the diminishing effect of city size on land-cover change relates to the degree of spatial dispersion of urban development and local differences in social valuation of diversified lands by cities.  相似文献   
93.
Estimated anthropogenic Hg emission was 11.9 tons in Pearl River Delta for 2014. Quantifying contributions of emission sources helps to provide control strategies. More attentions should be paid to Hg deposition around the large point sources. Power plant, industrial source and waste incinerator were priorities for control. A coordinated regional Hg emission control was important for controlling pollution. We used CMAQ-Hg to simulate mercury pollution and identify main sources in the Pearl River Delta (PRD) with updated local emission inventory and latest regional and global emissions. The total anthropogenic mercury emissions in the PRD for 2014 were 11,939.6 kg. Power plants and industrial boilers were dominant sectors, responsible for 29.4 and 22.7%. We first compared model predictions and observations and the results showed a good performance. Then five scenarios with power plants (PP), municipal solid waste incineration (MSWI), industrial point sources (IP), natural sources (NAT), and boundary conditions (BCs) zeroed out separately were simulated and compared with the base case. BCs was responsible for over 30% of annual average mercury concentration and total deposition while NAT contributed around 15%. Among the anthropogenic sources, IP (22.9%) was dominant with a contribution over 20.0% and PP (18.9%) and MSWI (11.2%) ranked second and third. Results also showed that power plants were the most important emission sources in the central PRD, where the ultra-low emission for thermal power units need to be strengthened. In the northern and western PRD, cement and metal productions were priorities for mercury control. The fast growth of municipal solid waste incineration were also a key factor in the core areas. In addition, a coordinated regional mercury emission control was important for effectively controlling pollution. In the future, mercury emissions will decrease as control measures are strengthened, more attention should be paid to mercury deposition around the large point sources as high levels of pollution are observed.  相似文献   
94.
珠江三角洲经济区耕地锐减,水资源分布不均,工业和农业污染严重,农业生态环境日趋恶化。经济发展不平衡,农业趋于萎缩状态,本文针对这些问题,提出了珠江三角洲农业生态环境治理的指导思想、发展目标和基本措施。  相似文献   
95.
采用GC-ECD和GC-MS分析了珠江三角洲淡水养殖鱼塘沉积物及鱼体中DDTs、PAHs的质量分数。结果表明,珠江三角洲地区鱼塘积物中DDTs质量分数范围为2.87~8.25ng·g-1,PAHs质量分数分布在61.76~196.05ng·g-1(干物质量)之间;鳙鱼、草鱼等5种鱼肌肉样品中DDTs质量分数为5.47~125.27ng·g-(1湿质量),PAHs质量分数为30.94~410.06ng·g-1(湿质量),5个品种鱼体内DDTs质量分数均未超过国家食用卫生标准。部分鱼塘中含有o,p’-DDT和p,p'-DDT,表明近期曾受到DDT污染。生态风险分析表明,珠江三角洲部分地区DDTs污染生态风险较高。  相似文献   
96.
Arsenic in groundwaters of the Lower Mekong   总被引:1,自引:0,他引:1  
Increasing incidence and awareness of arsenic in many alluvial aquifers of South-east Asia has raised concern over possible arsenic in the Lower Mekong Basin. Here, we have undertaken new research and reviewed many previous small-scale studies to provide a comprehensive overview of the status of arsenic in aquifers of Cambodia and the Cuu Long Delta of Vietnam. In general natural arsenic originates from the Upper Mekong basin, rather than from the local geology, and is widespread in soils at typical concentrations of between 8 and 16 ppm; (dry weight). Industrial and agricultural arsenic is localised and relatively unimportant compared to the natural alluvial arsenic. Aquifers most typically contain groundwaters of no more than 10 μg L−1, although scattered anomalous areas of 10 to 30 μg L−1 are also quite common. The most serious, but possibly ephemeral arsenic anomalies, of up to 600 μg L−1, are associated with iron and organic-rich flood-plain sediments subject to very large flood-related fluctuations in water level, resulting in transient arsenopyrite dissolution under oxidizing conditions. In general, however, high-arsenic groundwaters result from the competing interaction between sorption and dissolution processes, in which arsenic is only released under reducing and slightly alkaline conditions. High arsenic groundwaters are found both in shallow water-tables, and in deeper aquifers of between 100 and 120 m depth. There is no evidence of widespread arsenicosis, but there are serious localised health-hazards, and some risk of low-level arsenic ingestion through indirect pathways, such as through contaminated rice and aquaculture. An almost ubiquitous presence of arsenic in soils, together with the likelihood of greatly increased groundwater extraction in the future, will require continuing caution in water resources development throughout the region.  相似文献   
97.
黄河三角洲及珠江三角洲生态足迹分析   总被引:3,自引:0,他引:3  
利用遥感解译数据,分析了解珠江三角洲及黄河三角洲自然资本的供需状况,通过分析两大三角洲地区的生态足迹,探讨在经济发展程度不同的情况下,人类对生态环境的影响程度。并借鉴珠江三角洲经济发展过程中出现的问题,对黄河三角洲今后发展可能出现的问题提出预防措施,以减少对资源的不合理需求,提出正确的功能定位,制定正确的发展方向。研究结果表明,(1)黄河三角洲和珠江三角洲的生态足迹需求均高于全国0.8hm2/人的平均水平,珠江三角洲地区生态足迹需求为1.5403hm2/人;黄河三角洲地区生态足迹需求为1.3514hm2/人。(2)化石燃料的供需状况是影响两大三角洲地区生态赤字的关键因素,珠江三角洲地区对化石燃料的需求占总生态足迹需求的72.67%,位居全国第一位;黄河三角洲地区对化石燃料的需求占总生态足迹需求的49.85%。(3)珠江三角洲除林地尚有少量生态盈余外,其他生态足迹需求均存在明显的生态赤字。受城市化及工业化进程的影响,黄河三角洲化石燃料用地和耕地资源已出现生态赤字。(4)与西方一些发达国家相比,两大三角洲的生态足迹均呈现“低需求,低供给”的特点。  相似文献   
98.
本文首次详细论述了赛都糜棱岩型金矿的矿石类型、矿石组构和金属矿物的特征,对金矿物特征和金的赋存状态作了详细描述,并在矿石矿物学分析基础上提出了该金矿的矿化阶段。  相似文献   
99.
珠江三角洲降水化学成分的区域特征研究   总被引:9,自引:0,他引:9  
通过对珠江三角洲地区降水(降雨)化学成分的分析表明,该区可能存在二条降水物质通道,一条是从陆到海通道,从肇庆和广州分别至佛山、顺德、江门、台山、中山,至珠海出海,基本与西江和江河谷走向一致,另一条是从海到陆通道,从深圳始,到东莞和惠州,珠江口水面成为此二条通道的天然分隔屏障。地面源污染是造成该区局部降水酸度差异的调节因素,而造成全区降水酸化的根本原因是存在于平流层的区域性酸化大气层。南海海洋对降水  相似文献   
100.
辽河三角洲的自然资源与区域开发   总被引:23,自引:0,他引:23  
辽河三角洲有丰富的地上和地下资源,是农业综合开发和油田建设的重点地区。其区域资源开发以油田、稻田、苇田和虾田开发为核心,在土地利用主要做到全面规划与统筹兼顾;对淡水资源不足的问题要从开源与节流两方面来进行解决;对河口湿地景观生态系统要注意保护,发挥业已建立的自然保护区的功能;对河口湾水产资源更要加强保护与培育。  相似文献   
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