【作者】 张静；

【导师】 林建国；

【作者基本信息】 大连海事大学 ， 环境科学， 2010， 博士

【摘要】 随着我国经济社会的快速发展,海洋开发规模与强度持续加大,近海海域遭到越来越严重的污染,海域环境质量日趋恶化。海洋环境质量评价和海洋环境容量研究是环境保护的一项基础性工作,也是进行环境管理的重要手段之一。开展海洋环境质量评价方法研究,建立准确、有效、可操作性强的环境质量评价方法可以使评价过程更加简便,评价结果更具合理性；在全面了解海洋污染现状、正确评价海洋环境质量的基础上,开展海域主要污染物的环境容量研究,对制订区域特征污染物减排计划、减轻海洋污染压力、改善海洋环境具有重要意义。深圳湾是深圳、香港两地的界湾,承纳着深港两地的主要污染物,湾内严重的水污染问题与深港两地的高速城市发展形成较大反差,已成为制约深港两地和谐发展的主要因素。本文以“深圳湾环境容量与污染总量控制”研究项目为依托,在深圳湾2008年调查实测的数据之上,开展了深圳湾水环境综合评价及主要污染物环境容量研究,以期为实施深圳湾水质目标管理、污染物总量控制、海湾环境保护、海域有偿使用和海岸带综合管理提供科学依据。主要研究内容及研究成果如下：1、根据2008年深圳湾环境现状调查各因子的统计结果,选取10个水质指标进行了时空变化特征分析。结果表明：夏季水温最高、盐度最低,冬季水温最低、盐度最高,CODMn浓度雨季高于旱季；温、盐、CODMn的空间分布形态皆为冬季由湾内向湾外分布而其它三季由西岸向东岸分布；雨季非点源污染是湾内CODMn含量增高的主要原因。营养盐DIN浓度雨季大于旱季,而DIP和硅酸盐浓度旱季大于雨季；各营养盐空间分布并不相同,但均为湾内浓度最高。陆源排污、海底沉积物营养盐交换和珠江口水系雨季带来的高氮低磷低硅的海水是导致整个深圳湾海水中氮、磷、硅营养盐时空分布不尽相同的主要原因。石油类浓度的最高值皆出现在湾内深圳河口、湾中大沙河口和蛇口渔港附近海域,表明陆源排污和港口排污是深圳湾石油类的主要来源。重金属Pb、Hg的浓度旱季低于雨季,而Zn的季节变化恰好相反。Pb、Zn、Hg四个季节的空间分布并无一定的规律。陆源排污、大气—海洋双向输入以及深圳湾外围水质重金属浓度变化是导致整个深圳湾海水中不同性质重金属浓度时空分布不尽相同的主要原因。2、根据三类海水水质标准,在单因子评价的基础上,对原始数据的初值化采用以水质评价标准为约束的极值化方法,构建了基于线性隶属函数初值化方法的灰色关联评价模型,对深圳湾海水环境质量进行了综合评价。评价结果表明：深圳湾海水环境质量均属于Ⅳ类水质标准,污染的总体趋势是湾内大于湾中大于湾口；河口、码头处污染最严重。与常用的灰色关联评价模型相比,改进的灰色关联评价模型结合了灰色评价和模糊评价的优点,评价结果更加真实可靠。3、将三维斜压流干湿网格技术引入到POM模型中,对深圳湾海域的三维潮流场进行了模拟。计算结果表明：深圳湾海域属不正规半日潮,水平潮流属典型的往复流性质,潮流受地形约束基本呈西南—东北走向；落潮流速略大于涨潮流速；湾口流速大于湾内流速；表、中、底三层流场在结构上类似,受底摩擦的影响,表层流速略大于中层流速大于底层流速,且在潮流转流时刻,湾口一带都会出现一个逆时针的环流。整个流场垂向流速较小,存在着湾内上升、湾外下降的上下环流过程。4、将带有衰减项的物质输运方程耦合到带有干湿网格的POM模型中,采用分担率法计算了深圳湾COD、DIN和DIP的环境容量,并提出了根据水动力模型计算的响应系数场和分担率来确定混合区距离的公式。结果表明：深圳河和大沙河是影响全海域各种污染物含量的主要污染源。对COD,除大沙河雨季无排放容量外,其余各季各污染源均有排放容量。整个海域雨、旱季DIN和DIP都已经严重超标,无剩余容量,在总量控制中应采取严格的削减措施。5、针对深圳湾COD、DIN和DIP三种污染物的不同污染状况,分别提出了符合各个污染物污染特征的减排方案。结果表明：为使各污染物达到三类水质标准,在现状条件下,COD需少量减排,DIP需大幅度减排；在开边界水质DIN浓度达标的前提下,DIN也需大幅度减排。更多还原

【Abstract】 As the rapid development of economy, the scale and intensity of ocean development increase continuously. Coastal waters have being suffered more and more serious pollution, and the marine environment quality is deteriorating. Marine environment quality assessment and environmental capacity study is a basic task for environmental protection, and is also an important means for environmental management. According to study on marine environment quality assessment method, an accurate, effective and workable environment quality assessment method can be established, which can make the evaluation process more simple, the evaluation result more reasonable. Based on a comprehensive understanding of marine pollution status and a correct evaluation of marine environment quality, environmental capacity study on the main pollutants is great important for designing a emission reduction scheme of regional pollutants, reducing the pressure on marine pollution and improving the marine environment quality. Shenzhen Bay is a boundary bay between Shenzhen and Hong Kong, and the major pollutants of the two areas are inpoured into the sea. A large contrast between the serious water pollution problems in the bay and the rapid urban development of Shenzhen and Hong Kong has been formed and has become a main factor which restricts the harmonious development of the two cities. In this paper, supported by the research project of "Environmental Capacity and Pollution Total Amount Control of Shenzhen Bay", comprehensive assessment of water environment and environmental capacity of main pollutants are researched based on the monitoring data of Shenzhen Bay in 2008. Main contents and conclusions are as follows:1.According to the statistical results of Shenzhen Bay in 2008, ten indicators are selected to analyze their spatial and temporal variations. The results show that:the water temperature in summer is higher than that in winter, and the salinity in summer is lower than that in winter. The CODMn in rainy season is higher than that in dry season. The spatial distribution patterns of temperature, salinity and CODMn contours are consilient that the distribution is from the inner bay to the outer bay in winter and from the west coastline to the east coastline in other seasons. The non-point sources pollution in rainy season is the main reason for the increased values of CODMn. The DIN in rainy season is higher than that in dry season and is adverse for the DIP and silicon. The spatial distribution of nutrients is varied, but the highest concentration always appears at the inner bay. This is mainly caused by the high nitrogen, low phosphorus and low silicon sea water from the Pearl River in summer besides the terrestrial runoff and sediment nutrient exchanges. The highest concentration of oil always appears at the estuary of Sham Chun River, Dashahe and snake port sea area which shows that the sewage from land-based sources and port are the main source of oil in the bay. The Pb and Hg in dry season are lower than that in rainy season, and is adverse for the Zn. There are no disciplinary changes to follow for the temporal distribution of heavy metals including Pb, Zn and Hg. These are mainly caused by the land-based sources of sewage, the two-way input from the atmosphere-sea and the concentration changes of the heavy metals in external sea area.2.According to the third class standard, a single-factor evaluation method is used to evaluate the water quality. To restrict the extremum with the water quality standard, a further comprehensive evaluation is done by constructing a grey correlation evaluation model based on the value initialized method by using a linear membership function. The results show that:the water quality in Shenzhen Bay is in the fourth class standard and the overall pollution trends indicate that the inner bay is more serious than the middle of the bay, the middle of the bay is more serious than the mouth of the bay, and the estuaries and piers are the most serious. Compared with the common grey correlation evaluation model, the model in this paper combines with the advantages of grey and fuzzy evaluations, and can truly reflects the comprehensive characteristics of water quality in the actual evaluation.3.A three-dimensional, baroclinic wetting and drying scheme is introduced into POM model to simulate the three-dimensional flow field of Shenzhen Bay. The simulation results show that:the tide in Shenzhen Bay is an irregular semidiurnal tide, the horizontal tidal current is a reciprocating current and mainly in southwest-northeast direction by the restriction of the terrain. The tidal current velocity of ebb tide is slightly larger than that of flood tide. A similar structure has been shown in the flow fields of surface, middle and bottom layers. Influenced by the bottom friction, the tidal current velocity in the surface layer is slightly larger than that in the middle layer, and velocity in middle layer larger than that in the bottom layer. At the tidal current turning moment, a counter-clockwise circulation current always appears in the mouth of the bay. The vertical velocity of the whole flow field is slower. There exists a circulation current process which is up in the inner bay and down in the outer bay in Shenzhen Bay.4.A material transport equation with an attenuation item is coupled into the POM model. The sharing rate method is used to calculate the environmental capacity of COD, DIN and DIP and a distance formula of mixing zone based on the response coefficient and the sharing rate attained from the hydrodynamic model is proposed. The simulation results show that the Sham Chun River and Dashahe are the main pollution sources that influence the whole sea area. There are discharge capacities of COD in all pollution sources in the whole year except that there is no discharge capacity of COD in Dashahe in rainy season. The DIN and DIP throughout the sea area are far excessive and there is no remaining capacity both in rainy season and in dry season. A strict emission reduction scheme should be taken in total amount control.5.Three different emission reduction schemes for COD, DIN and DIP are proposed according to their different contamination status. The simulation results indicate that in order to agree with the third class standard, a little reduction for COD and a large reduction for DIP should be performed based on the status quo, and a large reduction for DIN is also needed based on the precondition that the DIN concentration at the open boundary meets the third class standard.更多还原