Predicting the aquatic risk of realistic pesticide mixtures to species assemblages in Portuguese river basins

Although pesticide regulatory tools are mainly based on individual substances, aquatic ecosystems are usually exposed to multiple pesticides from their use on the variety of crops within the catchment of a river. This study estimated the impact of measured pesticide mixtures in surface waters from 2002 and 2008 within three important Portuguese river basins(‘Mondego', ‘Sado' and ‘Tejo') on primary producers, arthropods and fish by toxic pressure calculation. Species sensitivity distributions(SSDs), in combination with mixture toxicity models, were applied. Considering the differences in the responses of the taxonomic groups as well as in the pesticide exposures that these organisms experience, variable acute multi-substance potentially affected fractions(ms PAFs) were obtained. The median msP AF for primary producers and arthropods in surface waters of all river basins exceeded 5%, the cut-off value used in the prospective SSD approach for deriving individual environmental quality standards. A ranking procedure identified various photosystem II inhibiting herbicides, with oxadiazon having the relatively largest toxic effects on primary producers, while the organophosphorus insecticides, chlorfenvinphos and chlorpyrifos, and the organochloride endosulfan had the largest effects on arthropods and fish, respectively. These results ensure compliance with European legislation with regard to ecological risk assessment and management of pesticides in surface waters.     

合肥市区典型景观水体氮磷污染特征及富营养化评价

为掌握合肥市环城河水系水环境状况,于2012年9月~2013年7月,在城区选取6个典型景观水体测定水体理化指标和叶绿素浓度,开展水体氮磷污染特征分析及富营养化评价,结果表明:①各水体氮、磷污染较为严重,TN和TP月平均浓度均远超过国际认可的发生水体富营养化临界值;②南淝河、黑池坝和雨花塘水体氮浓度表现出显著的逐月变化性,南淝河水体TP和PO3-4-P一直在较高浓度状态下波动,而银河公园水体则呈现显著的上升趋势;③雨花塘与黑池坝水体TN/TP比平均值分别为104.7和158.3,包河公园、银河公园、逍遥津公园和南淝河水体分别为16.8、18.7、6.4和16.8,表明雨花塘、黑池坝水体处于磷限制性状态,逍遥津公园为氮限制性状态;④聚类分析将6个景观水体聚为两大类,即污染严重的黑池坝和南淝河归为一类,其余4个相对封闭的水体为另一类;⑤营养状态指数评价结果表明,所有水体均处于富营养化状态,且富营养化程度排序为:银河公园>黑池坝>南淝河>逍遥津公园>雨花塘>包河公园.     

浙闽沿岸海域总溶解态无机锑的分布及影响因素研究

作为一种具有潜在致癌性的有毒稀有元素,锑已经广泛地存在于水体中并显现出较为严重的环境问题,引起科学界的广泛关注.利用氢化物发生原子荧光光谱法测定2008年5月浙闽沿岸海域水样中总溶解态无机锑(TDISb)的含量.结果表明,浙闽沿岸海域表、底层TDISb浓度的变化范围分别是0.68~5.64 nmol·L-1和0.71~5.25 nmol·L-1,平均含量分别为2.25、1.79 nmol·L-1,低于我国地表水环境质量标准和世界卫生组织规定的饮用水水质标准(约41.08 nmol·L-1).总溶解态无机锑表现出由沿岸向中央海区递减、表层高于底层的分布特征.影响浙闽沿岸海域溶解态无机锑分布的主要因素有水团混合,生物活动及悬浮颗粒物吸附解吸过程等.     

气候变化视角下的我国沿海地区防潮设计标准研究 ——以福州滨海新城为例

分析了福州滨海新城所面临的洪潮灾害风险和海堤建设规划情况.从全球气候变化导致福建沿海海平面上升的影响出发,介绍了国外沿海城市在考虑气候变化背景下如何确定海堤设计标准和我国防潮堤设计标准确定方法,分析了我国防潮堤现行设计标准存在的问题和风险,并对未来福州滨海新城防潮堤设计标准改进提出了建议,可供我国沿海地区相关问题参考.     

纳污海域水环境容量计算与总量分配方法研究——以钦州湾为例

经过比较,明确了选用多源线性迭加的方法来计算纳污海域环境容量更加便利和有效,确定了纳污海域水环境容量计算中的几个重要条件,在对“背景浓度”的处理上引入了最大日均值的概念,使得计算结果更加安全可靠。在此基础上,以广西钦州湾为例,用多元线性迭加法计算出纳污海域两个规划排污口联合排放的无机氮、COD、石油类的最大允许排放量。优化了污染物排放方法,为钦州湾污染物排放提供了科学依据。     

Establishing Eco-compensation Mechanism in Bohai Sea Waters under Framework of Ecosystem Approach

Ecosystem approach, a new comprehensive approach to the conservation and management of natural resources, has received universal concern and approval in the world, and it requires the application of the eco-compensation mechanism. Some basic ideas for establishing the marine eco-compensation mechanism are: payers and payees can be identified through analyzing marine ecosystem service changes and impacts on the stakeholders; financial transfer payment and environmental taxes and fees can be used as the main channels for compensation; payment standard can be set up by following the principle of a compromise between calculated theoretic results and “price bargaining”. Focusing on the key human impact on marine ecosystem in Bohai Sea, some preliminary ides on eco-compensation application are given: reform the ongoing charge system of pollutant discharge and enhance its incentives to reduce land pollutants; implement eco-compensation for freshwater demand between Bohai Sea and the river basins for the purpose of increasing freshwater inflow; popularize and strengthen the existing eco-compensation on fishery resources management, and implement the charge system of eco-compensation on reclamation from the sea for land construction.     

ESTIMATION OF COASTAL WATER CONTAMINATION LONG-TERM TREND USING SEASONAL LINEAR MODELS1

ABSTRACT: Bivalves are used as bioindicators to assess trends of the chemical quality of coastal and marine environments due to their ability to concentrate chemicals. These shellfish are subject to seasonal physiological changes influencing the chemical concentration. Using quarterly data, we model concentration via linear regression with a biologically based seasonal component. This was applied to cadmium concentration measured in the blue mussel (Mytilus edulis) at three sites in the Seine estuary (Normandy, France). In this case we have a high concentration season from January to June and a “low concentration” season from July to December. This season definition was checked a posteriori, using box-and-whisker plots and a statistical test of comparison of pair-wise adjusted least-squares mean differences, and it appears to be very reasonable. We averaged data by season and across sites. Our final model (R²= 0.846 with N= 27 observations) includes highly significant terms: a season effect, which accounts for 45% of the total variability, a linear and a quadratic time term. Outliers were identified by high Studentized residual values and attributed to bias in the temporal sampling schemes. The methodology developed will further be used with other shellfish and/or other trace elements and organic chemicals.     

COMPARATIVE STUDY OF FRESH-SALT WATER INTERFACES USING FINITE ELEMENT AND SIMPLE APPROACHES

ABSTRACT: The fresh-salt water interface in artesian aquifers has been investigated by various techniques on the basis of its analogy to the free surface in earth dams or cores of dams. Although various approximations are used, some more or less exact solutions exist. One of the simple methods, that would appeal to practical workers, was developed by the analysis of hydraulic forces. However, this method has not been checked thoroughly due to the lack of wide ranges of coverage by the more or less exact solutions. In this paper a suggested finite element method is used for the purpose of comparing with the method of hydraulic forces. The presented procedure eliminates some of the difficulties and uncertainties in current finite element procedures. Both methods proved to be in close agreement. Moreover, the hydraulic heads along the upper boundary of the artesian aquifer were found to be in close agreement with Dupuit's equation. The results of this investigation would greatly simplify the more complex management problems when the effects of discharge and/or recharge wells are added to the natural flow effects.     

上海市主要园林景观水体富营养化调查与评价

2004年8月,调查了上海市游人量超过200万人/年的7个公园中8个小型景观水体,调查结果表明,所有被调查的公园均已经达到富营养化状态,但是水体中营养盐的贡献度随景观水体的功能和管理而有一定的差异.因此科学的分析水体污染状况,采取相应措施加强对景观水体的管理,控制水体的进一步恶化已经到了刻不容缓的地步.     

粤东沿海地区的区域发展

在分析粤东沿海地区的概况、区域发展的优劣势条件基础上,结合粤东沿海地区的发展机遇,提出了区域发展的构思:扩大区域开放与协调、进行产业调整和升级、优化城镇体系和空间格局及人口发展对策.