舟山海域溢油行为与归宿

研究舟山海域溢油污染的问题,选用"油粒子"追踪模式,在潮流计算的基础上模拟了海上溢油动态.将海上溢油油膜离散为大量油粒子,每个油粒子代表一定油量,在表层海流和风的作用下漂移,而油膜的扩展则通过油粒子的随机走动来实现.本文以柴油为溢油油种,选择静风高潮时、低潮时和不利风向情况下的低潮时作为溢油初始时间,对溢油漂移路径及扫海范围进行了预测.     

海上溢油油膜运动不同数值模拟方法的比较研究

为能够迅速响应突发的海上溢油事故,本文利用油粒子法建立了溢油应急模型,以预测油膜漂移轨迹和形状。为弥补油粒子法无法模拟溢油初期油膜扩展过程和无法响应溢油量变化的缺陷,本文设计实验,使用将油膜扩展与油粒子法结合的两阶段法,发现能够较好地模拟溢油扩展过程;并用分数布朗运动代替传统布朗运动模拟油粒子扩散过程,模拟结果能够响应溢油量变化,更好地模拟油膜分散破碎的过程。模型中还考虑了蒸发过程使油粒子数量减少。     

长江口宝钢码头溢油事故油膜漂移扩散数值模拟

溢油事故发生后, 油膜的漂移扩散会对周围水域和环境敏感目标造成污染。研究溢油事故后油膜漂移扩散, 可为溢油事故的处理提供理论指导。本文应用河口海岸三维水动力模式ECOM-si(semi-implicit estuarine, costal and ocean model), 耦合溢油漂移扩散模块, 模拟和分析长江口宝钢码头发生溢油事故后油膜的漂移扩散, 以及对环境敏感保护目标的影响。基于长江口崇明东滩气象站实测风速风向资料, 给出影响溢油漂移的主导风和不利风向。在冬季多年平均1月径流量11700m³·s^-1、主导风、3个不利风和潮汐作用下, 数值模拟并详细给出了宝钢码头溢油事故发生后油膜的平面分布、油膜到达和离开4个水库取水口和饮用水水源保护区以及其他环境敏感保护区的时间、持续影响时间和最大油膜厚度。长江口宝钢码头溢油事故发生后, 油膜随涨落潮流作上下游来回振荡, 径流使油膜向海输运, 风使油膜朝风向方向漂移。在主导风北风5.6m³·s^-1风速下, 油膜沿长江口南岸向下游漂移扩散, 小部分进入北槽南侧。在不利风向东南风4.0m³·s^-1风速下, 油膜西北方向漂移, 聚集于南支北岸, 受径流作用沿南支和北港的中北侧向下游输运。在不利风向西北风4.8m³·s^-1风速下, 西北风减轻了溢油事故点上游和北港、崇明东滩外侧敏感目标的影响, 加重了南港和南槽的环境敏感保护目标的影响。在不利风向西南风3.2m³·s^-1风速下, 大部分油膜在北港中北侧向下游漂移扩散, 小部分油膜聚集在北槽的中北侧。西南风减轻了溢油事故点上游和下游南港、南槽环境敏感目标受到的影响, 加重了对北港和崇明东滩外侧敏感目标的影响。不同风向作用下油膜的分布和对环境敏感保护目标影响显著不同, 风在油膜漂移扩散中起着十分重要的作用。     

乐清湾北港区溢油轨迹的分形模拟

在验证良好的区域二维潮流数学模型基础上,建立采用“油粒子”方法的溢油模型,包含油膜的拓展、漂移和扩 散等过程。模型采用四阶龙格库塔法求解粒子的平流过程,采用分数布朗运动产生non-Fickian 扩散来模拟油膜拓延。在 此基础上,对乐清湾北港区溢油风险进行预测模拟,分析在潮流和风不同作用情况下油膜的漂移轨迹和对周围敏感区的影 响。     

海上溢油SAR遥感监测及溢油漂移快速数值预报技术研究

为探讨海上溢油遥感监测与溢油漂移数值模拟技术的联合应用,采用凝聚层次聚类算法从SAR遥感影像中识别油膜,采用基于风、浪、流耦合三维水动力模型研发的中国近海溢油漂移快速预报模型,将遥感识别结果作为溢油漂移数值预报模式的初始输入,预测油膜的漂移,然后将溢油漂移预测油膜与下一时相SAR遥感识别油膜进行比对,发现二者吻合较好,表明SAR遥感监测技术与数值模拟技术结合应用,可优势互补,同时获取海面油膜位置、面积和动态漂移信息。     

徐圩港区邻近海域溢油模拟分析

利用MIKE21水动力模型对徐圩港区附近海域进行潮流数值模拟,并利用实测资料对模型计算的潮位、流速及流向进行验证。验证结果显示:数模结果与实测值吻合较好。该潮流数学模型可以反映研究海域水动力特性,并作为溢油模块的水动力基础数据。基于欧拉-拉格朗日"油粒子"理论考虑油膜运动过程中扩散、蒸发、乳化等过程,建立了徐圩港区邻近海域二维溢油扩散模型,模拟不同潮时情况下发生溢油,考虑不同风况(夏季常风向、冬季常风向和最不利风向),分析不同情况下的溢油油膜漂移路径、漂移路程及扫海面积。结果表明:72 h内油膜最大扫海面积及漂移路程均出现在落潮期最不利风时溢油,分别为28.2 km2和25.8 km。在夏季常风和最不利风的落潮期发生溢油,油膜会经过口门飘向西北侧海域,对该区域生态环境会造成一定影响。     

青岛港码头溢油风险分析研究

本文采用油粒子模式,在模拟潮流的基础上分别预测了青岛港溢油油膜在静风,冬、夏主频风和不利风向4种情况下的动态漂移过程.通过对油膜运动漂移过程的模拟,具体分析了溢油发生后对周边的敏感目标产生的影响,从而为应急计划的制定提供一定的导向作用.     

溢油在海洋中的迁移变化以及对生态环境的影响

溢油是突发性污染事件。油的比重比海水轻,溢油入海飘浮在水面之上,逐渐扩散成油膜,随着潮流和风漂移,因此溢油入海同时参与三种过程: 其一是挥发过程:油溢出后,油中的易挥发组分物质逐渐蒸发,使溢油的总量逐渐减少。随着溢油范围的扩大,挥发面积加大,挥发速度加     

事故性溢油对湄洲湾环境影响的预测

本文采用已建立的湄洲湾潮流场和水质点拉格朗日运动模型，利用概率预测模式，描述一旦发生事故性溢油，海上表面油膜的漂移和扩展过程，预测最大可能的污染海域范围；并建立海上溢油动力模式，探讨连续排放溢油的漂移和扩展过程，通过Mackay公式算出在油膜覆盖下水体的油含量。     

蓬莱19-3 油田事故溢油数值模拟

利用FVCOM(Finite-volume coastal ocean numerical model)数值模型和MM5风场预报模式,在对渤海海域水动力场进行数值模拟的基础上,基于"油粒子"的欧拉-拉格朗日跟踪法和随机走动原理,并考虑风对溢油油膜漂移扩散的直接作用,建立了海洋溢油油膜漂移轨迹和扩散的数值预测模型。利用建立的模型对2011年6月蓬莱19-3油田事故溢油进行了数值模拟,模拟结果与RADARSAT卫星遥感监测数据相吻合。研究结果表明:在渤海中部地区夏季事故溢油模拟预测中,风漂移因子取0.024最为合理,模型可用于渤海蓬莱19-3油田附近事故溢油轨迹和扩散的快速预报,从而为该区域的溢油事故应急响应提供科学依据。     

NOAA的GNOME溢油模型在湄洲湾的应用

在湄洲湾试用GNOME溢油模型模拟溢油扩散．先用EFDC建立潮流场,并选用主导风形成常风场,一并输入GNOME建立起溢油模型,模拟涨、落潮过程叠加不同风况下敏感海域的溢油扩散．模拟结果：初始溢油量为100t,扩散到第6小时,8种不同条件下挥发油量都为7．7t,附岸和漂浮油量和为92．3t,其中漂浮油量为6．4～92．0t,相应附岸油量为85．9～0．3t;溢油扩散最大范围为1．3～30．0km。,90％置信区间为2．0～56．0km。,最大距离为1．2～14．6km;与前人模拟溢油扩散结果相比基本一致．经分析,溢油扩散主要受3个方面影响：（1）岸线走向：当岸线靠近油膜漂移的路线时,大量油膜附着在岸上,扩散范围较小;（2）风况与流场关系：如果两者方向一致,油膜会扩散较远;（3）风区长度：风区越长,油膜扩散范围越大．总之,建立GNOME溢油模型较好地模拟了溢油扩散趋势,对溢油应急响应具有参考作用．     

Oil-Spill Monitoring in the Coastal Waters of Hong Kong and Vicinity

In this study, we applied the edge-detection method of oil-spill monitoring to extract oil-spill features observed by the ENVISAT Advanced Synthetic Aperture Radar (ASAR) images over the coastal waters of Hong Kong and vicinity in northern South China Sea. Two examples in 2007 and 2008 over the coastal waters of the study area show that oil spills can be successfully detected by ASAR images at wind speeds around 4～ 6 m/s independent of wind direction. The study also shows that it could be helpful for evaluating the potential impacts of oil spills on the coastal environment in Hong Kong and vicinity.     

基于MIKE SA模型的厦门西港海域溢油影响的数值模拟研究

基于MIKE SA溢油模块,以燃料油为油种,建立了厦门西港海域溢油模型,模拟静风、主导风向（东北东风）和不利风向（西南风）3种风场条件下,一个潮周期内涨急、高潮、落急和低潮4个时段发生10 t溢油后油膜的漂移路径和影响范围.结果显示,发生在厦门西港海域的溢油在海面的漂移过程主要受潮流和风的影响,其中潮流起着主导作用.不同风向条件下,24 h内油膜的影响范围不同,静风条件下溢油浓度超一类（或二类,≥0.05 mg/dm3）、超三类（≥0.30 mg/dm3）和超四类（≥0.50 mg/dm3）的总影响面积分别为31.33、19.63和11.74 km2;主导风向条件下溢油浓度超一类（或二类）、超三类和超四类的总影响面积分别为99.62、69.01和8.99 km2;不利风向溢油浓度超一类（或二类）、超三类和超四类的总影响面积分别为8.38、5.05和2.10 km2.该预测结果可给出溢油事故发生后的影响范围、影响程度和影响敏感目标的时间,可为溢油事故应急决策的制定及溢油损害评估提供科学决策和支持,提升厦门海域环境风险管理应急能力建设.     

Modelling surface drifting of buoys during a rapidly-moving weather front in the Gulf of Finland, Baltic Sea

The Gulf of Finland is an elongated estuary located in the north-eastern extremity of the Baltic Sea. This semi-enclosed sea-area is subject to heavy sea traffic, and is one of the main risk areas for oil accidents in the Baltic. The continuous development and validation of operational particle drift and oil-spill forecasting systems is thus seen to be essential for this sea-area.Here, the results of a three-day drift experiment in May 2003 are discussed. The field studies were performed using GPS-positioned surface floating buoys. The aim of this paper is to evaluate how well models can reproduce the drift of these buoys. Model simulations, both in forecast and hindcast modes, were carried out by three different 3D hydrodynamic models, the results of which are evaluated by comparing the calculated drifts with observations. These models were forced by HIRLAM (High Resolution Limited Area Model) and ECMWF (European Centre for Medium-Range Weather Forecasts) meteorological forecast fields.The simulated drift of the buoys showed a good agreement with observations even when, during the study period, a rapidly-changing wind situation was observed to affect the investigation area; in this situation the winds turned about 100 degrees in half an hour. In such a case it is a very complicated task to forecast the drifters' routes: there is a need to regularly update the meteorological forcing fields and to use these regularly-updated fields throughout the simulations. It is furthermore recommended that forecasts should be made using several circulation models and several meteorological forecasts, in order to get an overview of the accuracy of the forecasted drifts and related differences in between the forecasts.     

珠江口溢油数值模拟

对珠江口海域流场进行了数值模拟。考虑风场对海面溢油物理和化学过程的影响,建立了考虑油膜扩展的溢油漂移轨迹数学模型,并对珠江口海域“12.7”溢油事故进行了数值模拟,为较全面了解溢油事故给珠海海域环境带来污染的过程提供了科学依据。     

渤海湾海面溢油数值计算

采用不规则三角形网格的分布杂交法，建立渤海湾潮流数值模型，在此基础上建立溢油飘移模型，计算在不同风场和潮流场的共同作用下，溢油飘移的输移轨迹、可能抵岸的时间、地点及残留量等。     

A probabilistic description of the wind over Liverpool Bay with application to oil spill simulations

Surface winds from the UK Meteorological Office mesoscale (12 km grid) atmospheric model have been used to define the wind at a location in Liverpool Bay during 1997–2001. Winds from the SW (centred on 240°) with a speed of about 10 m/s (20 knots) were the most frequent, although weaker winds from the SE were also common. The wind spectra were red in character and showed no evidence for a peak at the synoptic (2–5 day) time scale; however, a zero-up-crossing analysis suggested a dominant periodicity at 3.1 days, and at this time scale the winds were spatially coherent over a distance of 300 km. A wind direction transition matrix was derived to quantify the probability with which the wind changed between two specified directions. This information was then used with an estimate of the mean duration of a wind event to compute a stochastic wind time series that contained a similar energy level, periodicity, and direction variability to the archived wind data. The archived and stochastic winds were then used in 1000 oil spill contingency simulations during which estimates of the mean and minimum times taken for oil to reach the coastline, and the percentage of the oil impacting selected sites were computed. The stochastic winds provided more realistic results, when compared against those derived using the wind archive, than those obtained using a wind rose representation of the winds. The derivation and use of a stochastic wind time series has application to a range of modelling studies.     

胶州湾溢油污染研究

青岛港黄岛油区建成投产后,在扩大石油进出口量的同时,也使事故溢油污染概率增大,对胶州湾海水环境造成了威胁。从已经发生的油污染事件看,溢油多数是由于油船海损,其次是港口机具或储油设备损坏造成的。由于溢油多数是突然发生,在短时间内将大量石油泄漏海中,造成大面积海面或海滩油污染。溢油污染不但造成直接经济损失,而且油污染较长时间内难以清除干净,对海洋生态环境、沿岸旅游环境和社会环境都产生恶劣的影响,因此溢油污染危害早已引起青岛市有关部门的重视,先后开展了油污染监测和预报工作。本文根据胶州湾及邻近海域事故溢油污染预警、预报的需要,给出预报模型和典型天气下黄岛油区溢油行为和污染范围的预测,对有效地预防溢油污染和制定抢救、回收措拖及方案提供了重要依据。