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1.
本文采用频数分布法和压力-响应模型法分别推导小清河口营养物基准,其中频数分布法根据河口所有监测站位营养物浓度的下第5个百分点作为基准值;压力-响应模型法选取小清河口三种常见赤潮藻中肋骨条藻(Skeletonema costatum)、赤潮异弯藻(Heterosigma akashiwo)和微型原甲藻(Prorocent...  相似文献   

2.
海湾营养物基准是指对海湾地区没有不利或有害影响的环境营养物参数的最大剂量或浓度,能够为富营养化风险评估和水质目标管理提供参照条件。本研究根据2014—2017年的胶州湾现场监测数据,采用频数分布法、分类回归树模型以及非参数拐点分析等统计分析法,推导营养物基准候选值,并基于赤潮敏感藻生态响应,通过室内多藻种实验开展营养物基准校验。结果表明:不同方法得到的营养物基准值存在一定差异,多藻种实验得到的生态响应值普遍高于统计分析法得到的基准候选值。综合考虑胶州湾目前的水质状况及富营养化水平,胶州湾水体溶解无机氮、总氮、活性磷酸盐和总磷的营养物基准推荐值分别为0.152、0.394、0.003 2和0.008 9 mg/L。研究结果有望为青岛胶州湾水体富营养化控制和营养物标准制定提供科学支撑。  相似文献   

3.
大辽河口溶解态重金属的变化特征及影响因素研究   总被引:4,自引:0,他引:4  
分别于2009年7月和2010年4月在大辽河口采集表层水样,测定了水体中溶解态Cu、Pb、Zn、Cd和Cr的含量,并对其分布特征及影响因素进行探讨。结果表明:除2010年4月Cu,及个别站位Pb、Zn含量较高外,表层水重金属含量均达到国家一类海水水质标准。2010年4月表层水中Cu、Pb、Zn、Cr的浓度大于2009年7月,2航次Cu、Cd、Cr的含量由河向海呈逐渐上升趋势,2010年4月Pb、Zn的含量表现为河口段高于口外海滨。重金属的含量和分布主要受径流量、潮汐作用以及风浪扰动的影响。  相似文献   

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辽河口水域夏季营养盐分布与变化特征   总被引:5,自引:0,他引:5  
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6.
河口营养物基准是河口营养状态参数对生态环境不产生不良或有害影响的最大阈值。本文首先基于2015—2018年长江口环境现场调查数据开展河口内部分区,再通过主成分分析、相关性分析和线性回归分析等方法,筛选长江口营养物基准关键指标,之后采用频数分布法和压力-响应模型法得出基准推荐值,最后将赤潮优势藻培养实验得到的生态响应值作为参考。结果表明:根据盐度分布与地形特征,长江口可分为口门区和口外区两个生态区。可溶性无机氮(dissolved inorganic nitrogen,DIN)和可溶性活性磷酸盐(soluble reactive phosphorus,SRP)是制定长江口营养物基准的关键指标。口门区DIN和SRP的基准推荐值分别为0.614和0.029mg/L,口外区基准推荐值分别为0.295和0.008 mg/L。该结果有望为长江口富营养化评估和营养物标准制定等环境管理工作提供科学依据。  相似文献   

7.
辽河口海岸线近百年来的变迁   总被引:6,自引:0,他引:6  
运用遥感和GIS技术,对1979年的Landsat MSS、1988年的Landsat TM和2003年的SPOT-53种卫星影像进行了多源多时相遥感数据的分析和处理,并结合1909、1945和1990年3个时期的地形图等历史文献资料和野外实际调查工作成果,解译提取了辽河口5期的海岸线,分析、探讨了辽河口海岸线近百年来的变迁,结果表明:(1)1909~1945年,辽河水系的变迁和流域生态环境的破坏,导致盘锦湾海岸线迅速向海湾的中心外推,变迁面积达434 km2,盘锦湾面积急剧缩小;1945~1979年,由于辽河口附近滩槽的自然冲淤变化,盘锦湾逐渐变小直至消失,海岸淤积变迁面积达331 km2;1979年以来,辽河口区增建虾池、围海造田及新建油井平台等人类活动,对海岸线变迁的影响逐渐凸显,变迁面积达253 km2,完全改变了河口地区的景观格局。(2)与传统的地形图数据相比,卫星遥感方法极大地提高了获取所需信息的速度,具有更高的光谱分辨率、空间分辨率等技术上的优势,对及时调整应对海岸线变化的措施也有很大帮助,因此是海岸带动态监测研究的现代化的重要方法。  相似文献   

8.
辽河口三角洲前缘岸滩演变分析   总被引:1,自引:0,他引:1  
研究了辽河口三角洲前缘岸滩近50a来的演变特征,结果表明,在流域来水来沙减少的背景下,海域浅滩迎浪面普遍侵蚀后退,双台子河口拦门沙北偏东移,向口内发展,西滩滩外坡持续侵蚀,海域-2m、-5m等深线附近海床整体呈弱冲刷态势,近岸潮间带岸滩整体变化不大,相对平衡。结果可以为辽河口近岸工程建设和资源开发提供决策依据。  相似文献   

9.
辽河口水域溶解氧与营养盐调查与分类   总被引:6,自引:0,他引:6  
根据2003年9月辽河口水域营养盐和溶解氧的调查结果,讨论了辽河口水体中的溶解性无机氮(NO3-N、NO2-N、NH3-N)、活性磷酸盐(PO4-P)和溶解氧(DO)的含量、分布与变化特征以及相关关系。结果表明:辽河口溶解态无机氮含量范围为3.26~59.67μmol/L,活性磷酸盐含量范围为0.05~0.95μmol/L,溶解氧范围为0.086~0.208mmol/L。溶解氧、营养盐关系的统计分析结果表明:DIN与AOU(表观耗氧量),PO4-P与AOU之间显著或高度显著相关,营养盐之间也存在相关性,并对调查区域水质进行评价分类。  相似文献   

10.
辽河口海区悬浮体运移扩散动力特征   总被引:1,自引:0,他引:1  
控制着辽河口海区悬浮体运移的主要动力是河流迳流、潮流和余流.它们对最大浑浊带中河水与海水的混合,密度流循环以及悬浮物的沉降和运移共同起作用.悬浮物向海运移与河口区最大浑浊带有关,即与河流迳流、潮流和余流作用所控制的悬浮物数量有关。悬浮物向海运移似乎遵循两个周期:1.小潮—大湖周期;2.河流迳流丰枯周期.最大运移发生在大潮期和河流迳流丰水期。  相似文献   

11.
长江口上升流区营养盐的分布及其通量的初步估算   总被引:1,自引:0,他引:1  
根据2004年5月份长江口调查资料,分析了春季长江口上升流现象及其对营养盐分布的影响;初步估算了春季上升流的营养盐通量。结果表明:在春季,低温、高盐、低溶解氧的上升流稳定存在于122°20′~123°00′E,31°00′~32°00′N海区的10m 层和底层之间,并可以涌升到10m 层以上海区。上升流为上层海区输入了丰富的 PO_4-P 和相对低浓度的 NO_3-N 和 SiO_3-si。对上升流营养盐通量的计算表明,春季上升流中磷酸盐输送通量远高于长江径流输入,可能会成为影响该海区磷酸盐分布以及浮游植物生长的一个值得关注的因素:而氮和硅营养盐则不如长江径流输入量大。  相似文献   

12.
One of the key concerns in estuarine and coastal environments is eutrophication, which is known to be closely connected to nutrient enrichment. To control and improve surface water quality, nutrient criteria are recommended in order to provide reference conditions for the environment. However, the current datasets of nutrient criteria in China are either designed for surface water or sea water, and as such these are not suitable for assessing estuarine water quality, especially given the unique ecosystem and dynamic properties of estuaries. To address this issue in current estuarine water management, nutrient criteria have been developed for a local estuary in the southeast of China. Segmentation of the Jiulong River Estuary, China was firstly analysed through field investigations carried out during 2013–2014, which resulted in the delineation of three segments characterized by their distinct properties in relation to salinity, hydrology, ecosystems, etc. Historical records from 1997 to 2014 were then analysed using statistical modelling to develop candidate nutrient criteria for the estuary.This stage of the analysis was undertaken in combination with the study of nutrient status records from the 1980s,which were used to establish a baseline reference condition. The recommended criteria values of dissolved inorganic nitrogen(DIN) in Segments Ⅰ, Ⅱ and Ⅲ of the Jiulong River Estuary are 64, 21 and 14 μmol/L,respectively, and the corresponding values for soluble reactive phosphorus(SRP) are 0.89, 0.76 and 0.89 μmol/L,respectively. It should be emphasised that these values are site-dependent, and that different results may be achieved at other locations depending on the physical and biogeochemical characteristics of an estuary, or even a single site within a catchment. It is hoped that by demonstrating a possible methodological approach and methods of nutrient criteria derivation in the Jiulong River Estuary, the current study will offer researchers some fundamental basis from which to begin to develop more complete nutrient criteria indices for the study of nutrient conditions in other estuaries throughout China.  相似文献   

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为了明确大辽河流域范围内主要的生态环境问题、生态环境脆弱区和对流域生态安全非常重要的区域,根据流域湿地景观格局的变化及驱动机制分析、流域生态环境敏感性评价和水生态系统服务功能重要性评价,运用定性分区与定量分区相结合的方法和自下而上的划分方法得到大辽河流域水生态系统功能分区图,将大辽河流域划分成5个一级区和13个生态亚区。按照"水体类型+干扰类型+功能类型"对每个生态功能区进行命名,明确了每一个生态功能区的特征,为大辽河流域产业布局、生态环境保护与规划建设提供了科学依据。  相似文献   

15.
长江口最大浑浊带及邻近水域营养盐的分布特征   总被引:11,自引:0,他引:11  
根据2003年11月~2004年8月4个航次的调查数据,探讨了长江口最大浑浊带及邻近水域营养盐的分布特征。结果表明,营养盐浓度一般随盐度的增加而减小,不同营养盐表现出不同的平面分布和季节变化特点。最大浑浊带所处地理位置、水动力状况、高悬浮体含量以及生物活动等决定了营养盐分布不同于整个调查水域。与整个调查水域相比,最大浑浊带营养盐浓度更高;无机N的硝化作用进行得更为充分;高的DIN/PO4-P和SiO3-Si/PO4-P比(远高于Redfield比),相对低的SiO3-Si/DIN比等。透明度是最大混浊带浮游植物生长的主要限制因素。营养盐在河口的转移除了海水稀释作用外,还有部分的生物转移以及受悬浮体-沉积物系统的影响,特别是PO4-P。在最大浑浊带,富营养化现象更为严重。  相似文献   

16.
长江口湿地沉积物中的氮、磷与重金属   总被引:7,自引:0,他引:7  
研究了总氮NT、总磷Pt、重金属Cu,Zn,Pb和Cd在崇明东滩湿地沉积物中的分布与累积特征。结果表明,NT和重金属表现为:芦苇带〉互花米草带〉海三棱镳草带〉光滩,即从光滩至芦苇带,从南部至北部,NT和重金属的质量分数呈现逐步增加的趋势。由于高潮带以细颗粒为主,有机质含量较高,因此NT和重金属表现出相应的富集;而沉积物PT在各个湖带呈均匀分布,这主要与沉积物中磷的化学形态组成有关。与上海南岸潮滩湿地和世界其他河口湿地相比,东滩湿地沉积物中重金属的质量分数相对较低,表明它是一块保存较为完好未受到污染的天然湿地,这主要与长江径流对污染物的稀释作用有关。  相似文献   

17.
Identification of the limiting nutrient(s) is a requirement for the rational management of eutrophication. Here, we present the first experimental analysis of nutrient limitation of phytoplankton growth and its seasonal variation in the Guadiana estuary (SE Portugal-SW Spain). Ten microcosm experiments were performed during 2005 and 2008, using water samples collected in the freshwater tidal zone of the Guadiana estuary. Nitrate, phosphate and silicate were added in a single pulse, alone and in combinations. Experimental treatments were incubated for 4 days under controlled laboratory conditions. Phytoplankton response to nutrient enrichment was evaluated through changes in biomass (Chla), and abundance of specific phytoplankton groups.  相似文献   

18.
Tidal marsh exchange studies are relatively simple tools to investigate the interaction between tidal marshes and estuaries. They have mostly been confined to only a few elements and to saltwater or brackish systems. This study presents mass-balance results of an integrated one year campaign in a freshwater tidal marsh along the Scheldt estuary (Belgium), covering oxygen, nutrients (N, P and Si), carbon, chlorophyll, suspended matter, chloride and sulfate. The role of seepage from the marsh was also investigated. A ranking between the parameters revealed that oxygenation was the strongest effect of the marsh on the estuarine water. Particulate parameters showed overall import. Export of dissolved silica (DSi) was more important than exchange of any other nutrient form. Export of DSi and import of total dissolved nitrogen (DIN) nevertheless contributed about equally to the increase of the Si:N ratio in the seepage water. The marsh had a counteracting effect on the long term trend of nutrient ratios in the estuary.  相似文献   

19.
Although mitigation programmes have been implemented in huge eutrophied estuarine systems, satisfactory results are not always immediately achieved. External loadings are reduced but the nutrient pools still existing in the sediments (due to decades of external supply) start to deplete only slowly, to reach the lower steady state level related to the new external loading. In the Mondego Estuary, this situation could be seen from the mass balance calculations including different nutrient fractions (dissolved, SPM and bound in vegetation). Different nutrient fractions quantified over the year showed the retention capacity and supplying capacity of these estuarine systems, and also the seasonal dynamics those fractions can present. External loading of nitrogen was largely dominated by DIN, but after its incorporation by benthic primary producers nitrogen export occurred essentially as SPM-N. Phosphorus loading was dominated by SPM-P, but during warmer periods P-efflux increased DIP concentration inside the system and was afterwards exported through the outer boundary. Although nutrients bound in vegetation were not significant to total mass balance, depending on the occurrence of occasional macroalgal blooms, the vegetation fraction can significantly increase its contribution to the overall balance.  相似文献   

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