极端海况下海洋石油结构的风险评估

根据中国海上石油工业缺乏独立的风险评价体系的现状 ,笔者对极端海况进行了环境荷载的联合概率分析 ,利用随机模拟技术 ,求解结构的失效概率 ,提出结构失效分析的新方法 ,并利用DNV提供的历史数据 ,对结构失效的后果做了适当分析。以埕北 12 C井组平台作为实例 ,对平台甲板高程 (AirGap)失效分析进行了实例计算。结果表明 ,使用多维联合极值分布理论及相应的求解方法 ,是离岸工程结构物风险评估的重要手段。     

SUWANNEE RIVER LONG RANGE STREAMFLOW FORECASTS BASED ON SEASONAL CLIMATE PREDICTORS1

ABSTRACT: A study of the influence of climate variability on streamflow in the southeastern United States is presented. Using a methodology previously applied to watersheds in Australia and the United States, a long range streamflow forecast (0 to 9 months in advance) is developed. Persistence (i.e., the previous season's streamflow) and climate predictors of the previous season are used to forecast the following season's (winter and spring) streamflow of the Suwannee River located in northern Florida. The winter and spring streamflow is historically the most likely to have severe flood events due to large scale cyclonic (frontal) storms. Results of the analysis indicated that a strong El Nino‐Southern Oscillation (ENSO) signal exists at various lead times to the winter and spring streamflow of the Suwannee River. These results are based on the high correlation values of two commonly used measurements of ENSO strength, the Multivariate ENSO Index (MEI) and Sea Surface Temperature Range 1. Using the relationships developed between climate and streamflow, a continuous exceedance probability forecast was developed for two Suwannee River stations. The forecast system provided an improved forecast for ENSO years. The ability to predict above normal (flood) or below normal (drought) years can provide communities the necessary lead time to protect life, property, sensitive wetlands, and endangered and threatened species.     

海上溢油事故应急反应系统的框架研究

一旦发生海上溢油事故,溢油事故应急反应系统将有效地组织溢油事故的各种应急处理,以确保海洋生态系统的安全和减少经济损失。文章对海上溢油事故应急反应系统的总体框架进行了分析,并详细介绍了以溢油信息收集子系统、溢油模拟子系统、环境与资源信息数据库、溢油应急指挥中心及溢油应急处理系统五大部分为主体的框架及其主要功能。该框架可作为建立海上溢油事故应急反应系统的基础。     

Water sharing agreements sustainable to reduced flows

By signing a water sharing agreement (WSA), countries agree to release an amount of river water in exchange for a negotiated compensation. We examine the vulnerability of such agreements to reduced water flows. Among all WSAs that are acceptable to riparian countries, we find out the one which is self-enforced under the most severe drought scenarios. The so-called upstream incremental WSA assigns to each country its marginal contribution to its followers in the river. Its mirror image, the downstream incremental WSA, is not sustainable to reduced flow at the source. Self-enforcement problems can be solved by setting water releases and compensations contingent to water flow. We apply our analysis to the Aral Sea Basin. We compute the upstream incremental compensations for the Bishkek agreement and asses its vulnerability with historical flows.     

Recent Changes in the Hydrobiology of the Aral Sea

Since 1992 attempts have been made to isolate and conserve the northern part of the Aral Sea of means of a dam. Changes in the main aquatic communities between 1985 and 1994 based on field work, laboratory investigations and literature surveys are described and the future prospects for the region are discussed.     

基于陆海统筹的海洋生态环境管理体系研究

经过近60年的探索和实践,我国海洋生态环境管理机制体制不断完善,海洋生态环境综合管理能力显著提升。本文立足我国海洋生态环境管理现状,重点从强化制度约束性、机制协同性和政策指导性等角度分析了存在的主要问题,阐述了陆海统筹的海洋生态环境管理体系框架,并提出了构建以生物多样性保护为核心的海洋生态环境管理分区、建立以氮磷污染物为重点的陆海协同排放管控制度、完善以监测评估为核心的海洋生态监管制度、建立以入海河流和海湾为重点的区域联防联控机制和完善以海洋生态补偿和赔偿为核心的财政政策等重点任务,可为建立陆海统筹的生态环境治理制度提供参考。     

十二烷基苯磺酸钠(SDBS)及消油剂对刺参幼参的急性毒性

为探究表面活性剂对海洋棘皮动物的影响,测定了十二烷基苯磺酸钠(SDBS)和消油剂对刺参(Stichopus japonicas )幼参的急性毒性。结果显示,SDBS对刺参幼参的72 h-LC₅₀和96 h-LC₅₀分别为2.50和1.71 mg·L^-1;消油剂对刺参幼参的96 h-LC₅₀为7 498.94 mg·L^-1。刺参幼参相对于多刺裸腹溞(Moina macrocopa )和脊尾白虾仔虾(Palaemon carincauda )对SDBS的敏感性较高,相对于安氏伪镖水蚤(Pseudodiaptomus annandalei )对SDBS的敏感性则较低,SDBS对刺参幼参的毒性明显大于十二烷基磺酸钠(SDS),消油剂的96 h-LC₅₀ 远远大于SDBS和SDS,毒性非常小,但这仅是对刺参幼参而言,大多数研究忽视了消油剂自身对生物体存在的影响,因此这方面的研究工作还需要继续开展。     

The rise of thermophilic sea urchins and the expansion of barren grounds in the Mediterranean Sea

Recent ecological studies have shown a strong relation between temperature, echinoids and their grazing effects on macro-algal communities. In this study, we speculate that climate warming may result in an increasingly favourable environment for the reproduction and development of the sea urchin Arbacia lixula. The relationship between increased A. lixula density and the extent of barren grounds in the Mediterranean Sea is also discussed.     

Polycyclic aromatic hydrocarbons in red mullet (Mullus bavbatus) and sediments from the Eastern Aegean Sea

The distribution of polycyclic aromatic hydrocarbons (PAHs) was investigated in red mullet (Mullus barbatus) and sediment samples in the eastern Aegean Sea. The data were collected during cruises in July and November 1994, in the framework of National Marine Measurement and Monitoring Programme in the Aegean Sea. PAHs were detected in the tissue of Mullus barbatus of different sex and size from nine sampling sites throughout the study area ranging from 0.03 to 0.46 ug/g (fresh weight). The observations show the high levels of PAHs were found in tissues of females. The average concentration of PAHs in Aegean Sea sediments ranged from 0.20 to 1.8 ug/g (dry weight). No significant correlation was observed between PAH and sedimentary organic carbon.