Estimation of Annual Energy Output from BCM Tidal Barrage and the Corresponding Marine Environmental Impact

Based on the finite-volume coastal ocean model(FVCOM),a three-dimensional numerical model FVCOM was built to simulate the ocean dynamics in pre-dam and post-dam conditions in Bachimen(BCM).The domain decomposition method,which is effective in describing the conservation of volume and non-conservation of mechanical energy in the utilization of tidal energy,was employed to estimate the theoretical tidal energy resources and developable energy resources,and to analyze the hydrodynamic effect of the tidal power station.This innovative approach has the advantage of linking physical oceanography with engineering problems.The results indicate that the theoretical annual tidal energy resources is about 2×10~8 k Wh under the influence of tidal power station;Optimized power installation is confirmed according to power generation curve from numerical analysis;the developable resources is about 38.2% of theoretical tidal energy resources with the employment of one-way electricity generation.The electricity generation time and power are 3479 hours and 2.55×10~4 KW,respectively.The power station has no effect on the tide pattern which is semi-diurnal tide in both two conditions,but the amplitudes of main constituents apparently decrease in the area near the dam,with the M_2 decreasing the most,about 62.92 cm.The tidal prism shrinks to 2.28×10~7 m^3,but can still meet the flow requirement for tidal power generation.The existence of station increases the flow rate along the waterway and enhances the residual current.There are two opposite vortexes formed on the east side beside the dam of the station,which leads to pollutants gathering.

Changes in Sedimentation Rate of Tidal Flat and Environmental Significance at Qidong Foreland of the Yangtze Estuary

The sedimentation rate is an important environmental parameter to understand the evolution of coastal geomorphology. The tidal flat around Qidong foreland is located in the junction between Yangtze Estuary and Jiangsu coast,where the land-ocean interactions are strong and highly sensitive to environmental changes. The QDZ-1 core sediments collected at Qidong foreland was analyzed for137 Cs dating and grain size.The results showed that silt is the main sedimentary type with a trend of gradually fining from the bottom to the top,conforming to the sedimentation characteristic of the silt muddy tidal flat. The sedimentation rate could be divided into three distinct stages: 1963 to 1986 was 2. 61 cm/yr,1963 to 2011 was 1. 82 cm/yr,and 1986 to 2011 was 1. 10 cm/yr. Based on these,further explanation was made for the significance of environmental changes. According to the estimation of sedimentation rate,the impact of extreme environmental change was reflected by the sudden increase in sand proportion at the depth of 172. 5 cm. Since the introduction of Spartina alterniflora in the 1970 s,it has played an important role in tidal flat development. The tidal flat has a high sedimentary rate during this time. With continuous accretion of the tidal flat,low tidal flat turns to high tidal flat,the sedimentation rate gradually declines,and tidal flat sedimentation appears.

浙江海岸带泥质滩涂物源示踪研究:来自矿物包裹体中磁性矿物的证据

土地资源是浙江沿海地区发展的重要限制性因素。丰富的滩涂资源一直被视为当地最重要的后备土地资源。准确示踪其物质来源,是科学管理滩涂的重要基础。由于在海水中的长期浸泡,矿物被部分溶解,进而影响沉积物的地球化学和矿物学性质,增加示踪结果的不确定性。通过矿物包裹体的磁学特征研究浙江沿海滩涂的物质来源,由于不受海水溶蚀影响,其结果更可靠。对浙江滩涂沉积物中矿物包裹体的环境磁学研究发现:(1)样品的主要载磁矿物依然是磁铁矿;(2)磁铁矿的含量明显降低,饱和等温剩磁(SIRM)值为9.1×10^(-5)—28.6×10^(-5)A·m^(2)·kg^(-1),仅是原样的2%—8%;(3)样品的赤铁矿与磁铁矿比重较原样明显降低。酸处理后样品的磁化率值(χ)仅为1.0×10^(-8)—2.3×10^(-8)m^(3)·kg^(-1),极易受到测量误差的影响,因此无法准确反映样品中磁铁矿含量的空间分布特征,而在强磁场下获得的磁学参数更适合于矿物包裹体的环境磁学研究。基于非磁滞剩磁磁化率(χ_(ARM))、SIRM及饱和等温剩磁退磁参数的散点图和模糊聚类方法可以区分长江和浙江当地河流的物质,是可信赖的物源示踪手段。根据矿物包裹体的磁学特征,提出浙江滩涂沉积物主要来源于当地河流的悬浮颗粒物。

Sedimentary facies and textural characteristics of Cretaceous sandstones in the southern Bida Basin,Nigeria:Implication for reservoir potential and depositional environment

A study of sedimentary facies,mineral and textural characteristics of sections of conglomerates/pebbles and sandstone facies found within the Lokoja and Patti Formations in southern Bida Basin,Nigeria,is carried out to evaluate the paleo-environment and reservoir quality of the sandstones of the formations through field observations and textural and mineralogical(using X-Ray Diffractogram)analyses.Nine lithofacies are identified and grouped into three main facies associations.These sedimentary facies suggest deposition in both foreshore and estuaries.The mineral analysis(XRD)shows that the quartz content in sandstone facies of the Lokoja Formation ranges between 49%and 67%,and that of the Patti Sandstone between 43%and 56%,indicating a quartz dominance.The granulometric studies reveal that the Lokoja Formation comprises coarse-to medium-grained(-0.63 to 1.30φ)sandstone with moderatepoor sorting of 0.72e1.824.On the other hand,medium to fine-grained sandstones dominate the Patti Formation,which is averagely poorly sorted(1.29-1.54φ).The sandstones are coarsely skewed to finely skewed,with the kurtosis ranging from very platykurtic to leptokurtic.Morphological results of the pebbles from both Lokoja and Patti Formations indicate that the study areas are mainly characterized by the interplay of both wave and fluvial processes,which suggests that the environment of deposition of sandstone facies is predominantly of the fluvial to the shallow marine environment with the indication of tidal influence.Integrating sedimentary facies and textural results suggests subtidal sand ridge/foreshore,estuarine mudflat,and estuarine delta environments with fluvial influences.Evidence from the textural and mineral characteristics indicate that the sandstone facies of the Lokoja and Patti Formations are fairly matured and can act as potential hydrocarbon reservoirs in the formations.The facies,XRD mineral,and textural results have revealed potential hydrocarbon reservoir areas and paleo-depositional features of the Lokoja and Patti Formations.

基于一维河网模型的崇明岛水环境容量计算

平原河网地区的水环境治理修复是一项艰巨复杂的综合系统工程,合理计算水体的水环境容量,对于确定水环境综合治理工程的规模尤为重要。以上海市崇明岛为研究区,通过构建一维水动力水质模型,基于模型模拟结果计算了研究区内各河段不同时期的水环境容量,分析了各河段水环境容量的时间变化趋势,结果表明,不同污染因子水环境容量差异较大,其中COD的水环境容量比相应水文期NH_(3)^(-)N和TP的水环境容量大;不同水文期水环境容量差异也较大,即各指标在丰水期的水环境容量均大于枯水期。另外,由于水环境容量受河段长度、水质降解系数的影响,河段长度越长,水质降解系数越大的河段水环境容量越大。

感潮河网中围区内河道水环境容量研究

水环境容量是水资源规划管理的一个重要依据,为研究感潮河网中围区内河道水环境容量,分析了现有的水环境容量计算方法,根据感潮河网中围区内河道水文水动力特征,在感潮河网四典型流模式的水环境容量模型基础上,提出了基于一维动态水质模型解析解的单围区整体模式的水环境容量计算方法,并且成功应用于容桂联围内河涌水环境容量的计算。结果表明,该方法对于感潮河网中围区内河道水环境容量计算简便且有效。

Assessment of Soil Quality of Tidal Marshes in Shanghai City

We take three types of tidal marshes in Shanghai City as the study object:tidal marshes in mainland,tidal marshes in the rim of islands,and shoal in Yangtze estuary.On the basis of assessing nutrient quality and environmental quality,respectively,we use soil quality index(SQI)to assess the soil quality of tidal flats,meanwhile formulate the quality grading standards,and analyze the current situation and characteristics of it.The results show that except the north of Hangzhou Bay,Nanhui and Jiuduansha with low soil nutrient quality,there are not obvious differences in soil nutrient quality between other regions;the heavy metal pollution of tidal marshes in mainland is more serious than that of tidal marshes in the rim of islands;in terms of the comprehensive soil quality index,the regions are sequenced as follows:Jiuduansha wetland>Chongming Dongtan wetland>Nanhui tidal flat>tidal flat on the periphery of Chongming Island>tidal flat on the periphery of Hengsha Island>Pudong tidal flat>Baoshan tidal flat>tidal flat on the periphery of Changxing Island>tidal flat in the north of Hangzhou Bay.Among them,Jiuduansha wetland and Chongming Dongtan wetland have the best soil quality,belonging to class III,followed by Nanhui tidal flat,tidal flat on the periphery of Chongming Island and tidal flat on the periphery of Hengsha Island,belonging to class IV;tidal flat on the periphery of Changxing Island,Pudong tidal flat,Baoshan tidal flat and tidal flat in the north of Hangzhou Bay belong to class V.

江苏省车轴河感潮河段建闸调水减淤方案优化研究

针对感潮河段挡潮闸闸下淤积问题,通过实施挡潮闸调水可以达到减淤目的。为了满足河床不淤和生态环境需水要求,通过构建江苏省连云港市车轴河闸二维水沙数学模型,研究了不同调水方案对于闸下淤积的影响,并进行方案比选。结果表明:保持车轴河河床不淤的日均下泄流量为1.28 m^(3)/s,车轴河生态环境需水量为0.88 m^(3)/s,因此保持车轴河不淤的流量可满足生态流量要求。在洪季水量充足的情况下,可采取全天闸门常开方案,流量为3.0 m^(3)/s时对下游河床的减淤效果提升显著。在枯季水量较少时,可采取在涨急时段开闸方案,流量取8.0~18.0 m^(3)/s,相对落急时段开闸方案,涨急时开闸对闸门稳定的影响较小且减淤范围较大。

潮滩湿地硝化螺菌的代谢潜力和环境适应机制

为了揭示硝化螺菌(Nitrospira)在潮滩湿地中的代谢潜力和环境适应机制,本研究使用宏基因组学拼接与组装的方法,从中国沿岸的5个潮滩湿地构建了14个较高质量的Nitrospira基因组.系统发育分析结果表明,在这些基因组中,3个属于全程氨氧化细菌(complete ammonia oxidizer,Comammox);9个为硝化螺菌世系Ⅱ和Ⅳ;2个属于至今未见报道的世系Ⅲ型.这表明,潮滩湿地富含多样化的硝化螺菌类群.代谢分析表明,潮滩湿地Comammox和典型的Nitrospira含有氰酸酶、脲酶以及参与腈类、酰胺类化合物分解的酶,暗示着它们能够与氨氧化微生物耦合利用有机氮作为能源.此外,Nitrospira有着多重压力抵抗、病毒防御和渗透压调控策略.这些结果深化了对Nitrospira在潮滩湿地的多样性、生态功能潜力和环境适应机制上的认识.

渤海湾南部滩涂贝类群落结构特征及其环境因子相关性研究

本研究以渤海湾南部(滨州)滩涂为研究区域,设置6个断面共36个采样站位,覆盖潮间带(高潮带-中潮带-低潮带)和潮下带,研究该区域贝类资源群落结构特征及其环境因子相关性。结果表明:整个调查区域常见贝类总共有30种。潮间带共有23种常见贝类,优势种为光滑篮蛤(Potamocorbula laevis Hinds 1843)、四角蛤蜊(Mactra quadrangularis Reeve 1854)、短文蛤(Meretrix petechialis Lamarck 1799);潮下带共有26种常见贝类,优势种为中国蛤蜊(Mactra chinensisi Philippi 1846)、等边浅蛤(Gomphina aequilatera Sowerby 1825)、朝鲜笋螺(Terebra koreana Yoo 1976)、红带织纹螺(Nassarius succinctus A.Adams 1852)、纵肋织纹螺(Nassarius variciferus A.Adams 1851);潮间带贝类多样性指数(H')和均匀度指数(J')显著高于潮下带,而丰富度指数(D)则相反;潮间带贝类生物量(710.16 g/m^(2))和栖息密度(4523个/m^(2))远高于潮下带(17.10 g/m^(2),35个/m^(2))。群落结构多元统计分析将贝类按照站位划分为5个组群,包括东侧潮下带、西侧潮下带、西侧潮间带、东侧潮间带以及D4站位。冗余分析(RDA)结果表明,对潮间带贝类影响较大的环境因子主要为沉积物的粒径以及砂、粉砂含量,而对潮下带贝类影响较大的主要为浮游植物密度、沉积物的粒径以及砂、粉砂和黏土含量。渤海湾南部(滨州)滩涂贝类资源较为丰富,但应从不同滩涂区域生态特性的角度出发,加强贝类的保护和资源修复,本研究可为该区域贝类的资源养护和可持续利用提供数据基础。

MIKE11水质模型在流域水环境中的应用综述

MIKE 11水质模型是应用于水体进行情景模拟预测的数学模型,是研究水体环境的重要工具。本文简要介绍了MIKE 11水质模型,总结MIKE 11模型在流域水环境的污染治理、感潮河网治理、水环境容量计算、流域安全预警等方面的应用。

设施西瓜土壤养分投入与累积及环境风险分析

为明确河北省设施西瓜主产区养分投入、累积与氮素淋失风险,选取81个设施西瓜大棚与27个对照农田,进行实地调研与土壤样品采集,评价土壤养分丰缺状况与累积量,预测硝态氮淋失风险。结果表明:设施西瓜田有机肥和化肥平均用量分别为47550和1301.48 kg/hm^(2),是农田的1.10倍和1.27倍,土壤中氮、磷、钾养分表观盈余量分别是携出量的5.00、7.21和2.96倍。0~20 cm土层中,硝态氮、有效磷、速效钾和有机质处于丰富水平,分别占比70.37%、33.33%、100%和40.74%,且各养分含量随着土层加深而逐渐降低。设施西瓜田0~60 cm土层硝态氮、有效磷和速效钾的平均累积量分别是农田土壤的1.43、1.53和1.69倍。并且设施西瓜田土壤硝态氮向下层迁移明显,分别在60~80 cm和120~140 cm出现累积峰;模型预测在150~400 cm土层有均有较高累积量,是农田的8.33~9.55倍。因此,河北省设施西瓜田养分投入量过高,易造成土壤养分的高累积与硝态氮向深层淋失,对地下水存在氮污染的风险。

长江口潮滩环境信息系统功能设计研究

该文在对长江口潮滩环境信息系统研究紧迫性分析的基础上,总结了长江口潮滩环境信息系统实现的总体目标、技术路线,同时阐述基于组件技术实现长江口潮滩环境信息系统的总体思路。

崇明东滩湿地芦苇和互花米草种群的分布格局及其与生境的相关性

应用GIS技术与实地调查相结合的方法,对上海崇明东滩湿地芦苇〔Phragmites australis(Cav.)Trin.exSteud.〕和互花米草(Spartina alterniflora Loisel.)种群斑块的分布格局和沿潮位梯度的分布特征及其与部分环境参数的相关性进行了研究。结果显示:在1 500 m×100 m尺度内共有42个斑块;其中,互花米草种群斑块数量较少(13个)但面积和周长均较大,呈集中化分布特征;芦苇种群斑块数量最多(25个)但面积和周长均较小,呈现破碎化特征;芦苇种群的斑块密度和边缘密度均大于互花米草种群,但二者的聚集度指数及连通度指数均较高。沿潮位降低,芦苇种群数量减少,互花米草种群数量增多;中、低潮位以互花米草种群为主,中、高潮位以芦苇种群为主。不同潮位二者活体与立枯体株数有明显差异且具有不同程度的相关性,其中,互花米草总株数与芦苇活体株数、互花米草立枯体株数与芦苇立枯体株数均呈显著负相关(P<0.05)。该区域内各景观和斑块类型格局指数数值均较高,Shannon多样性和均匀性指数均较大。不同潮位的环境参数差异明显且与距堤坝的距离有不同程度的相关性;中潮位相对高程最高(9.2 m),低潮位土壤盐度最高(37.17 ng.L-1);随潮位降低土壤总氮和总磷含量总体上下降,但中高潮位土壤总磷含量最高、高潮位土壤总氮含量最高。芦苇活体株数与距堤坝的距离及土壤盐度、互花米草活体株数与相对高程及土壤总磷含量、互花米草总株数与相对高程均呈显著负相关(P<0.05)。研究结果揭示:该区域景观已出现破碎化现象;互花米草种群规模逐年增大,与芦苇种群有明显的竞争,二者呈明显的镶嵌分布格局。高潮位的相对高程低而土壤盐度高,这种微生境有利于互花米草生长却能抑制芦苇生长,对二者的扩散和分布格局产生复杂的局部性影响。

江苏中部粉砂淤泥质滩岸大剖面所揭示的滩岸发育过程与环境演变

通过对39个钻孔组成的长约10km的江苏中部粉砂淤泥质滩岸大剖面地层与沉积物的多项指标分析发现,江苏大丰一带现代潮滩及潮下带的位置上,40～20KaBp之间曾为潮滩环境,20～10Ka沉积间断、地层缺失,10Ka以来曾一度发育古潮流沙脊群,现代潮滩仅仅是近几百年来在潮流沙脊群之上发育而成的。

突发水污染事故中污染物输移主导水动力识别——以深圳湾为例

河口地区感潮河段水动力过程复杂,为在突发水污染事故中合理制定精细化应急方案,基于环境流体水动力模型(EFDC)从水动力学角度对不同水文条件下深圳河口水域突发水污染事故的影响范围、时间及程度进行了数值模拟分析,提出了一种判断河口海湾地区主导水动力因素的分析方法。采用基于傅里叶变换的频谱分析法对事故中污染物输移扩散的主要影响因子进行了准确识别,并采用单因变量多因素方差分析法进行了印证。结果表明,潮流是感潮河段水动力过程的主要驱动因素,但在突发水污染事故中,深圳河各断面特征污染物浓度变化与陆地径流关系密切,径流是感潮河段内突发事故中特征污染物输移的主导动力因素。

温州鳌江近海建设工程环境影响潮汐潮流数值模拟

收集了近年来鳌江口附近海域多个工程不同阶段5个潮位站的3-5年潮位实测数据和部分海流实测资料，通过对鳌江口附近海域的不同年份的水位资料进行潮汐调和常数分析，鳌江近海海域主要为半日潮区，其中 M2分潮的振幅在170-193 cm；迟角在260°-280°之间，这些站的2007年、2010年、2011年调和常数分析结果相比，主要的半日分潮 M2、S2、N2，全日分潮 K1、O1及浅水分潮 M4、MS4、及 M6等分潮振幅、迟角的最大变化分别在1.8-4.4 cm 和3°-7°之间。在初步掌握了鳌江口潮汐潮流特征的基础上，采用无结构的三角形网格和有限体积法的 FVCOM 海洋数值模型，进行模拟结果验证，计算结果与实测数据符合良好。构建重点年份建设工程合拢产生新的岸线水深的潮汐潮流场，刻画鳌江口建设工程的叠加影响。

乳山口潮汐能电站环境收益评估

进入21世纪,能源安全和环境问题已成为全球化的问题。改善能源结构、发展可再生能源,已经成为我国能源建设的主要任务。潮汐能作为清洁的可再生能源,除了替代传统不可再生能源,还具有减少污染损害和温室气体排放的环境收益。因此,本文针对潮汐电站的环境收益,以拟建乳山口4万kW级潮汐电站为例,同时使用替代市场法和条件价值法,对比评估了该潮汐电站的环境收益价值范围,讨论了替代市场法和条件价值法在评估潮汐电站环境收益的应用可行性。由替代市场法估算的环境收益为5191.30万元/a;在条件价值法下,运用Tobit模型估算结果为1184.19万元/a,因而乳山口4万kW级潮汐电站的环境收益区间为1184.19-5191.30万元/a。该评估结果为判断可再生能源项目投资的经济可行性提供科学依据。

中国沿海滩涂的环境管理体制及其改革

我国沿海滩涂的生态环境恶化严重。其环境管理体制不畅是重要原因之一。我国当前沿海滩涂环境管理体制结症体现在三个方面:是一种分散管理体制;是一种地方为主、中央为辅的管理体制;是一种环境保护从属于经济开发的管理体制。概括而言,目前的沿海滩涂管理体制是"分散管理、资源管理、入口管理"。要破解当前沿海滩涂环境管理体制结症,关键是设置职责明确的沿海滩涂管理委员会,从而实现沿海滩涂的"综合管理、生态管理、过程管理"。

基于EFDC模型研究文昌清澜潮汐汊道人类活动对水交换速率的影响

文中利用水龄浓度概念,结合计算水交换时间的水质模型公式,在 EFDC（环境流体动力学模型）水动力基础上,分别计算了1965年和2006年清澜潮汐汊道的海湾水交换时间。研究结果表明,2006年的平均水交换时间为107d,1965年的平均水交换时间为114d,发生变化的主要原因是清澜港航道被浚深至7-8m,潮汐动力显著增强,纳潮量增加了4.3%所致。