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1.
为全面了解广西北部湾近岸海域营养盐与富营养化程度,于2021年8月和2022年1月在珍珠湾、钦州湾、廉州湾、铁山港和涠洲岛海域共27个站位采集表层水,分析营养盐浓度,并运用营养盐限制因素评价方法和富营养化指数法分析营养盐结构特征和富营养化状况。结果表明:广西北部湾近岸海域夏季表层水体溶解态无机氮(DIN)、磷酸盐(PO43--P)和硅酸盐(SiO32--Si)均值分别为0.177 mg/L、0.019 mg/L和0.578 mg/L,冬季三者分别为0.162 mg/L、0.021 mg/L和0.324 mg/L,营养盐浓度均为SiO32--Si>DIN>PO43--P;其中DIN和SiO32--Si平均值在夏季高于冬季,而PO43--P为夏季略低于冬季。各海湾营养盐浓度大小依次为铁山港和钦州湾>廉州湾>珍珠湾>涠洲岛,且在4个海湾均呈湾内向湾外递减的空间变化趋势。夏季氮磷摩尔比(N/P)、硅氮摩尔比(Si/N)和硅磷摩尔比(Si/P)分别为4.3-35.2,0.5-6.5和12.0-139.9,对应均值分别为19.6,2.0和35.5,以潜在磷(P)限制为主,占所有站位的29.6%;氮(N)限制占14.8%,其余站位无营养盐限制的情况。冬季N/P、Si/N和Si/P分别为4.3-36.2,0.8-2.0和8.4-37.1,对应均值分别为20.4,1.1和21.5,以潜在P限制为主,占所有站位的36.4%;N限制占9.1%。夏季富营养化指数E为0.04-3.92,平均值为1.13;冬季富营养化指数E为0.03-3.68,平均值为1.08,夏季富营养化程度略高于冬季。总的来说,北部湾近岸铁山港富营养化程度最高,其次为钦州湾,两者绝大部分海域均已达到中度富营养,廉州湾30.0%海域达到轻度富营养,而珍珠湾和涠洲岛均属于贫营养。本研究结果可为北部湾海洋环境保护和海水养殖提供基础数据。  相似文献   

2.
2021年10月(秋季)对廉州湾近岸海域进行现场调查,分析廉州湾营养盐的分布特征,并利用富营养化指数和有机污染指数对该海域海水水质进行等级划分与评价。结果显示:秋季廉州湾海域的溶解态无机氮(DIN)浓度为0.149-1.587 mg/L,均值为0.493 mg/L;溶解态无机磷(DIP)浓度为0.010-0.084 mg/L,均值为0.033 mg/L;化学需氧量(COD)浓度为0.89-3.27 mg/L,均值为1.47 mg/L。DIN呈现近岸高、中部低的分布;DIP由湾内至湾外呈递减趋势,梯度分布明显,受河流输入影响显著。调查区域的富营养化指数为0.48-76.25,均值为12.23,大多数站位的水质状况属于轻度至中度富营养水平,严重富营养化主要出现在南流江口附近的站位;有机污染指数为-0.15-7.20,均值为1.80,研究区域50%的水质受到不同程度污染,南流江水质污染最严重,属于严重污染水域。总体来看,河流输入的陆源污染和人类对廉州湾海域的开发利用,是廉州湾海域富营养化和有机污染程度高的主要原因。  相似文献   

3.
陶晓娉  吴淼  刘熊  雷富  何喜林 《广西科学》2022,29(3):532-540
为全面了解广西北部湾海域水质污染状况,根据广西北部湾海域2021年8月(夏季)和2022年1月(冬季)表层海水调查数据,利用单因子污染指数法、有机污染指数法和综合污染指数法对广西北部湾海域进行水质污染分析和评价。研究表明:广西北部湾海域表层海水夏季和冬季pH、溶解态无机氮(DIN)、溶解态无机磷(DIP)和溶解氧(DO)存在不同程度超标,主要污染物为DIN和DIP,钦州湾和铁山港是各单因子主要超标海域。有机污染方面,仅夏季钦州湾湾内存在1个重度污染站位,在钦州湾和铁山港湾内出现中度污染,夏和冬两季分别占18.5%和13.6%,其余受污染海域同时出现在钦州湾、廉州湾和铁山港,夏和冬两季良好水质仅占3.7%和22.7%,均位于涠洲岛海域。综合污染方面,未发现严重污染水域,仅钦州湾在夏季出现中度污染,轻度污染在夏和冬两季分别占40.7%和31.8%,夏季除涠洲岛外其他海域均受到综合污染,冬季仅钦州湾和铁山港受到综合污染。整体而言,单因子超标率、水体有机污染和综合污染程度在夏季高于冬季,在湾内高于湾外。  相似文献   

4.
2003~2010年铁山港湾营养盐的变化特征   总被引:1,自引:0,他引:1       下载免费PDF全文
蓝文陆  彭小燕 《广西科学》2011,18(4):380-384,391
2003~2010年对广西铁山港湾进行22个航次的调查,采集海水样品分析该港湾硝酸盐氮、亚硝酸盐氮、氨氮、无机氮、活性磷酸盐和活性硅酸盐8年的浓度变化特征和季节变化特征,并结合文献资料,比较该期间铁山港湾与钦州湾海水营养盐浓度变化的异同.结果,2003~2010年间铁山港附近海域无机氮浓度为0.21~47.86μmol...  相似文献   

5.
【目的】调查及评价钦州湾近岸海域夏季海水富营养化水平状况。【方法】2010年6月采集钦州湾近岸海域15个站位的海水样品,测定海水中化学需氧量(COD)、无机氮(DIN)、活性磷酸盐(PO4-P)等的浓度;采用单因子污染指数法对污染程度进行评价,采用海水富营养化指数法以及潜在富营养化程度评价模式对海水富营养化水平进行评价。【结果】钦州湾近岸海域夏季海水中COD平均浓度为1.00mg/L,DIN平均浓度为0.12mg/L、PO4-P平均浓度为0.01mg/L。单因子污染指数法评价结果显示,钦州湾近岸海域海水中COD浓度符合国家一类海水水质标准;DIN浓度超标率为20%;PO4-P浓度超标率为20%。海水富营养化指数法评价结果显示,钦州湾海域海水富营养化指数平均值为0.47;海水潜在富营养化程度评价模式评价结果显示,钦州湾海域海水营养级别为Ⅱ级。【结论】钦州湾近岸海域海水受无机氮及活性磷酸盐污染;海水富营养化水平为贫营养;钦州湾近岸海域海水富营养化程度主要受陆源污染物及海水养殖影响。  相似文献   

6.
钦州三娘湾营养盐的分布及其化学特性   总被引:1,自引:0,他引:1       下载免费PDF全文
为了解广西钦州三娘湾营养盐的化学特征及其分布规律,2000年3月15日对钦州三娘湾3条断面、9个测站进行表层水样采集,分析水样中的硝酸盐(NO3-N)、亚硝酸盐(NO2-N)、氨氮(NH3-N)和无机磷(PO4-P)。结果表明,三娘湾水域的营养水平不高,无机氮的含量(2.85μmol/L)分别比北海湾(26.06μmol/L)和钦州湾(42.54μmol/L)和10.9%和6.7%。但比铁山港(0.99umol/L)高1.88倍;而其无机磷含量(0.14μmol/L)与其他3个海湾的差异不大。三娘湾无机氮的含量分布由东北向西南呈规律性递减趋势;无机磷则以东南远岸测站含量较高。向西北沿岸呈递减趋势。该水域大部分测站N/P均在21.00以上,处于磷相对缺乏状态,氨态氮与盐度、pH值、COD、SS的相关系数分别为-0.845,-0.962,0.407和0.535。NO3-N与NO2-N和NH3-N的相关系数分别为0.736和0.769。  相似文献   

7.
为了解近海工程疏浚对海湾生态环境的影响,2015年7月,分别在不同工期(施工期、非施工期)和潮时(高潮、低潮),对广西钦州湾疏浚工程进行共4个航次的现场跟踪监测,比较不同施工状态下疏浚工程对海湾生态环境的影响。结果显示,疏浚工程的施工扰动使水体中悬浮物、溶解无机氮(Dissolved Inorganic Nitrogen,DIN)和溶解无机磷(Dissolved Inorganic Phosphorus,DIP)浓度显著增加。疏浚工程附近站点DIN和DIP浓度比对照站点大幅增加,最大增幅分别为151.7%和580.0%,DIP增加幅度大于DIN增加幅度。疏浚活动导致沉积物营养盐释放,明显改变了局部海区营养盐浓度的分布格局。在钦州湾外湾,疏浚工程引起的内源磷元素释放强于氮元素,改变了海湾的营养盐结构特征(cN/cP值)及浮游植物磷胁迫/限制状态,可能引发水华或赤潮,需要加以关注。  相似文献   

8.
文章根据2016年3月、5月、8月和10月四个航次对防城港珍珠湾养殖区表层海水的调查资料,分析该海域海水中COD、DIP、DIN的空间分布特征和时间变化规律,同时,采用富营养化指数法对该海域的富营养化现状进行分析评价。结果表明:COD、DIP、DIN的均呈现出近岸高于远岸、湾底高于湾口的空间分布特征;其中,COD、DIP均于夏季达到最高值,DIN于秋季达到最高值;调查海域全年均未呈现出富营养化状态,富营养化指数在夏季达到最高值。  相似文献   

9.
广西沿岸主要海湾潮流的数值计算   总被引:1,自引:0,他引:1       下载免费PDF全文
广西沿岸的铁山港、廉州湾、钦州湾、防城港湾的潮流数值计算结果显示,4个海湾的落潮流均大于涨潮流,最大落潮流速120cm/s,最大涨潮流速100cm/s,潮流为往复流型式,落潮由北向南,涨潮由南向北,流向具有明显的规律性,这与实测结果较为吻合,但在钦州较为杂乱,存在2个互反方向的回旋式流动,究其原因,可能是与该湾的地理环境条件有关。  相似文献   

10.
廉州湾近岸的海水理化要素含量的变化特征   总被引:1,自引:0,他引:1       下载免费PDF全文
根据2003年7月至2004年6月廉州湾近岸水质监测资料,以DIN、PO4-P、COD为富营养化评价指标,分析廉州湾近岸海水理化要素测值的变化特征。结果表明,廉州湾内河口区海水富营养化程度分布较高,湾口区相对较低;水温季节变化不大,盐度春夏季低秋冬高,pH值季节变化不明显,COD夏季明显高于春季,活性硅酸盐冬季较低,DIN春季高于冬季,PO4-P春季大于冬季,廉州湾沿岸水质变化的主要原因与河口径流、沿岸河水、水产养殖排放物有关。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

13.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

14.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

15.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

17.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

18.
本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。  相似文献   

19.
In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.  相似文献   

20.
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