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61.
区域洪水灾害风险评估体系(Ⅰ)——原理与方法   总被引:2,自引:2,他引:2  
区域洪水灾害风险评估是一个新的研究领域。从洪水灾害系统的概念出发,首先阐述了洪水灾害风险管理系统、洪水风险评估及风险类型划分;然后从指标选取原则、指标层次结构、指标量化、风险等级、风险指数等方面构建了洪水灾害风险评估指标体系;接着分析了矢量面状及栅格点状的洪水灾害风险评估单元;最后,介绍了适合区域洪水灾害风险评估的层次分析法、模糊综合评价法及空间分析方法。  相似文献   
62.
The aim of this study was to investigate the pollution characteristics of typical veterinary antibiotics in manure and soil of livestock farms in Jiangsu province. This investigation employed solid-phase extraction (SPE) coupled with ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). A total of 53 manure and 50 amended soil samples from 16 livestock farms in Jiangsu province were collected for analysis. In the manure samples, the highest detected frequencies and concentrations were those of tetracyclines (TCs, 54.1 ± 5775.6 μgkg?1), followed by fluoroquinolones (FQs, 8.4 ± 435.6 μgkg?1), sulphonamides (SAs, 3.2 ± 5.2 μgkg?1) and macrolides (MACs, 0.4 ± 110.5 μgkg?1). Statistical analysis was used to illuminate the pollution characteristics of 23 veterinary antibiotics for various animal types and different regions in Jiangsu province. The results showed that the pollution level in cow manure was relatively lower compared with pig and chicken manure due to the relative restriction of medication. Furthermore, contamination was serious in amended soil from chicken farms. The pollution level in manure among different regions was higher to the south and north compared with the centre of the region. The same outcome was found for soil. Antibiotic residues in organic fertilizer were also investigated in this study. We found that although the detected concentration was lower in organic fertilizer than in fresh manure, detection frequencies (10–90%) were high, especially for roxithromycin (90%) in MACs (30–90%). This finding suggests attention should be paid to the pollution levels in organic fertilizer. This study is the first extensive investigation of the occurrence and distribution of many kinds of typical veterinary antibiotics in manure and soil from livestock farms of Jiangsu province. This investigation systematically assesses veterinary antibiotics usage and related emissions in southeast China.  相似文献   
63.
文章论述了二的化学成分及主要来源 ;二的毒性 ;日本、美国、德国等国二恶英污染状况及各国制定的标准  相似文献   
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Fecal contamination of water bodies causes a public health problem and economic loss. To control such contamination management actions need to be guided by sound science. From 2007–2009 a study was undertaken to determine the sources of fecal bacteria contamination to the marine waters adjoining the Town of Wrightsville Beach, North Carolina, USA. The research effort included sampling for fecal coliform and Enterococcus bacteria, sampling for optical brighteners, dye studies, and use of molecular bacterial source tracking techniques including polymerase chain reaction (PCR) and terminal restriction fragment polymorphism (T-RFLP) fingerprinting of the Bacteroides–Prevotella group. Of the 96 samples collected from nine locations during the study, the water contact standard for Enterococcus was exceeded on 13 occasions. The T-RFLP fingerprint analyses demonstrated that the most widespread source of fecal contamination was human, occurring in 38% of the samples, with secondary ruminant and avian sources also detected. Optical brightener concentrations were low, reflecting a lack of sewage line leakage or spills. A lack of sewer leaks and lack of septic systems in the town pointed toward discharge from boat heads into the marine waters as the major cause of fecal contamination; this was supported by dye studies. Based on these data, the Town initiated action to have the U.S. Environmental Protection Agency declare the coastal waters (out to 3 nautical miles), the nearby Atlantic Intracoastal Waterway and its tributaries a no-discharge zone (NDZ) to alleviate the human fecal pollution. The Town garnered supporting resolutions from other local communities who jointly petitioned the North Carolina Department of Environmental and Natural Resources. This State regulatory agency supported the local government resolutions and sent an application for an NDZ to the EPA in April 2009. The EPA concurred, and in February 2010 the coastal waters of New Hanover County, NC, became the first marine area on the U.S. eastern seaboard between Delaware and the Florida Keys to be declared a no-discharge zone.  相似文献   
67.
Residues from the imported wastes dismantling process create a great burden on the ambient environment. To develop appropriate strategies for the disposal of such residues, their characteristics were studied through background value analysis and toxicity leaching tests. Our results showed that the heavy metals concentrations in residues were high, particularly those of Cu (7180 mg kg?1), Zn (2783 mg kg?1), and Pb (1954 mg kg?1). Toxicity leaching tests revealed a high metal releasing risk of such residues if they are disposed of in a landfill. However, the residues of imported wastes were also found to have some intrinsic metal recycling value.  相似文献   
68.
Poultry litter generated on the Delmarva Peninsula is from phytase-modified bird diet and bisulfate amendment. To establish agronomic application rates in conservation tillage systems, bisulfate-amended phytase-diet poultry litter was investigated for its nutrient release kinetics and supply capacity under simulated weathering conditions. Delmarva poultry litter was packed in PVC columns (15 cm i.d. × 25 cm height) to a depth of 5 cm and leached intermittently with 600 mm of water for 190 days. Concentrations of various nutrients in leachate were analyzed and nutrient release kinetics were modelled. Poultry litter leachate contained high contents of dissolved organic carbon (DOC, 35–11,800 mg L?1), nitrogen (N 6–2690 mg L?1), phosphorus (P 45–225 mg L?1), potassium (K 20–6060 mg L?1), and other nutrients. Release of the nutrients occurred primarily in the starting 5 weeks and mostly followed a first order Exponential-Rise-to-Maximum model. Under the specified conditions, the poultry litter demonstrated a nutrient supply capacity of 11.7 kg N Mg?1, 5.4 kg P Mg?1, and 36.8 kg K Mg?1. Release of the potentially plant-available N and K was nearly finalized within 190 days of leaching/weathering, but it would require two years for full release of the leachable P. The results indicate that with consideration of field conditions, surface application of bisulfate-amended phytase-diet Delmarva poultry litter at recommended 6.6 Mg ha?1 to conservation tillage systems would largely provide P 25.0 kg ha?1, N 106.6 kg ha?1, and K 245.5 kg ha?1 to seasonal crops.  相似文献   
69.
在对美国水质标准经济分析研究的基础上,结合我国环境管理的实际情况,构建湖泊营养物标准的技术经济评估框架。计算标准建议值条件下的湖泊营养物容量及入量湖,得到削减量。通过不确定性优化模型对削减量进行分配,核算湖泊富营养化控制成本,并假设标准执行后,对流域经济造成的影响进行评估。将该方法应用于抚仙湖营养物标准的技术经济评估系统,结果表明,通过优化模型对削减量进行分配的削减成本较原规划低,通过构建的技术经济评估框架对该成本进行评估,标准执行后,对流域经济影响适中。  相似文献   
70.
邹晶 《世界环境》2006,(1):17-23
上世纪六七十年代,美国发生过不少环境重大事故,有的造成了较大的人员伤亡,有的还是发生在国外。但如今,美国在应对环境危机的各个方面,如立法、机构、人员培训、行政程序、信息披露等方面都走在了世界的前面。那么,过去的几十年,美国又是走过了一条什么样的路程?他们遇到了怎样的困境?社会对此又有什么反应?近日,我刊对美国环保协会中国项目首席经济学家杜丹德(Daniel J.Dudek)博士进行了采访。[编者按]  相似文献   
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