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1.
黄河下游营养盐浓度、入海通量月变化及“人造洪峰”的影响 总被引：9，自引：3，他引：6
于2009年至2011年在黄河下游采集溶解及颗粒态营养盐样品,分析了黄河下游各形态营养盐的浓度变化及营养盐入海通量,结果表明各形态氮的浓度多呈丰水期低、枯水期高,溶解无机氮是溶解态氮的主要存在形式;受黄河高悬浮颗粒物含量的影响,磷以颗粒态占绝对优势,而溶解态磷以溶解无机磷为主要存在形态;生物硅的含量平均约占硅酸盐与生物硅之和的20％,硅的浓度丰水期高于枯水期.颗粒态磷与生物硅的含量与悬浮颗粒物含量呈正相关.营养盐的组成具有高氮磷比、高硅磷比、低硅氮比的特点.近年来黄河下游溶解无机氮浓度显著升高而溶解无机磷变化不大,硅酸盐的浓度有所下降.黄河下游水沙通量、营养盐入海通量有明显的季节变化,丰水期占全年总入海通量的42％～84％.调水调沙期间,各营养盐的浓度和组成均有明显变化,氮的浓度、DIN/PO4-P下降,磷与硅的浓度、SiO3-Si/DIN、SiO3-Si/PO4-P升高,颗粒态营养盐的比例明显增加.短期内大量水沙及营养盐入海通量对黄河口及渤海生态系统产生重要影响. 相似文献
2.
黄河下游溶解态营养盐季节变化及入海通量研究 总被引：1，自引：0，他引：1
《中国海洋大学学报(自然科学版)》2017,(3)
根据在2010-04—2011-03期间在黄河利津站进行的观测结果,分析了黄河下游营养盐的月际变化,估算了黄河营养盐的入海通量。结果表明:观测期间溶解无机氮(DIN)、硝酸盐(NO_3~--N)、亚硝酸盐(NO_2~--N)和氨氮(NH_4~+-N)浓度的变化范围分别为190.4~361.3、177.1~332.5、0.74~13.81和2.27~26.44μmol/L,平均浓度为277.5、269.3、4.90和5.26μmol/L;磷酸盐和硅酸盐浓度的变化范围为0.027~0.138和92.5~146.0μmol/L,平均浓度分别为0.094和118.1μmol/L。DIN的浓度表现为枯水期含量高、丰水期含量低,而磷酸盐的变化与其相反;硝酸盐是黄河下游水体中溶解无机氮的主要组成部分,且溶解无机氮的入海通量主要由NO_3~--N贡献;磷酸盐浓度与径流量显著正相关;丰水期黄河向渤海输送的溶解无机态营养盐是全年输送通量的主要贡献者,营养盐通量的主要控制因素是径流量。 相似文献
3.
2012年2月至2014年3月在黄河下游采集水样,分析黄河下游营养盐浓度与通量的月际、季节性以及在调水调沙期和暴雨期的变化情况,并估算了调水调沙期和洪水期输水量和营养盐入海通量对黄河年入海通量的贡献。结果表明NO3- 是TDN的主要存在形式,各形态氮营养盐枯水期高于丰水期;DIP是TDP的主要存在形式,PIP是TPP的主要存在形态,颗粒态磷和DSi丰水期高于枯水期。黄河水体中具有高DIN/DIP和DSi/DIP,低DSi/DIN,严重偏离Redfield比值。营养盐输送通量具有很强的月际变化,在径流量及输沙量最大月份也存在营养盐入海通量峰值。2002-2012年10年间调水调沙和暴雨在营养盐输送通量上占黄河下游营养盐输送通量的23%~68%和5%~59%,对营养盐年入海通量的平均贡献分别为 38%和24%,二者均在短期内导致水、沙和营养盐的大量输送,将对黄河口及其邻近海域的生态环境产生重要的影响。 相似文献
4.
黄河下游营养盐浓度季节变化及其入海通量研究 总被引：7，自引：0，他引：7
2001年3月～2002年2月期间在黄河下游采集溶解及颗粒态营养盐样品,分析了黄河径流中各形态的营养盐的浓度及其月动态,估算此时段内黄河的营养盐入海通量。研究发现,溶解无机氮是溶解总氮的主要存在形式,硝酸盐是黄河中氮的最主要存在形态,其季节变化与水量变化趋势相反,年平均含量为(260.6±84.0)μmol/L,显著高于世界其它河流,为世界背景值(7.14μmol/L)的20多倍;黄河中磷主要以颗粒态存在,颗粒态磷含量变化规律与SPM的分布一致,其年平均含量为(16.2±22.9)μmol/L,磷酸盐含量较低,年平均含量为(0.42±0.20)μmol/L,与世界河流的平均水平相当。硅酸盐年平均含量为(122.0±18.2)μmol/L。每年约有17 200 t的总氮和1 600 t的总磷输入渤海,氮通量表现出在春季3月较高;磷通量在9月出现最高值,春季3,4月也较高;硅酸盐通量在3月出现最高值。 相似文献
5.
依据改革开放40 a来胶州湾营养盐状况历史资料以及2018—2019年的现场调查,对胶州湾营养盐历史变化过程及其生态效应进行了系统分析。结果表明:营养盐的浓度变化大致以2008年为分界节点,在2008年前胶州湾溶解无机氮(DIN)浓度呈现持续上升趋势,而溶解无机磷(DIP)、活性硅酸盐(DSi)浓度则先略有减少后快速增加;2008年后胶州湾3种营养盐浓度均快速减少。营养盐限制状况由20世纪80年代初期的氮限制、20世纪90年代的硅限制转变为目前的磷限制。胶州湾Chl a年均质量浓度一直在3μg·L^-1上下波动但近年来则呈下降趋势,浮游动物生物量1994年后大幅度增加。分析发现,入湾营养盐通量的增加和海域面积缩小是2008年前胶州湾营养盐浓度增加的主要原因,而近十几年来胶州湾环境综合整治措施的大力实施则是氮、磷营养盐浓度减少的主要原因。2010年以前贝类养殖是控制胶州湾浮游植物生物量的主要因素,但近年来溶解无机磷浓度的减少和浮游动物生物量的增加是Chl a质量浓度呈下降趋势的主要原因。 相似文献
6.
镭、氡同位素示踪调水调沙对黄河口水体运移及营养盐分布特征的影响 总被引：2，自引：0，他引：2
为研究调水调沙影响下的镭、氡同位素和营养盐在黄河口的分布特征,于2013年7月调水调沙期间在黄河口及其邻近海域进行了多点的连续观测。研究发现:(1)黄河口海域镭、氡同位素分布呈现明显的“分区”现象,南北两区分别为“调水调沙影响非显著区域”和“调水调沙影响显著区域”,北部海域镭、氡同位素浓度高值主要来源于陆源输入(包括河流输入和海底地下水排放);(2)调查期间,北部海域水体年龄为(2.9±1.6)d,南部海域水体年龄为(5.0±2.1)d;水龄随潮汐变化表现出涨潮时水龄增大、落潮时水龄减小的波动趋势;(3)北部海域溶解无机氮(DIN)和溶解硅(DSi)含量明显高于南部海域,而溶解无机磷(DIP)在两个区域的含量相差不大。 相似文献
7.
黄河干流营养盐分布与变化趋势 总被引：4，自引：0，他引：4
河流是海洋获取陆源物质的主要途径,河流营养盐含量和结构的变化会对海洋生态环境产生重要影响。为了解黄河干流营养盐的基本情况及影响因素,于2012年7月(汛期)对黄河流域水体和土壤进行了综合调查,并结合历史资料分析了悬浮颗粒物和营养盐等的变化特征及对黄河物质输送的影响。结果表明:各参数受地势和人类活动的影响明显,表现出不同的分布特征。营养盐和悬浮颗粒物在上游浓度较低,在中游相对稳定,下游浓度有一定程度升高;相比于贵德而言,黄河利津段悬浮颗粒物、溶解硅和硝酸盐分别增加了近66%、60%和800%。磷限制是黄河营养盐限制的主要特征,且氮磷比呈升高趋势;与资料对比发现,黄河氮增加约1倍,硅下降60%后相对稳定,而磷略有下降。从目前分析看,支流与干流的氮营养盐构成有显著差异。在沿岸表层土壤营养盐含量较高的区域,河段内营养盐含量也较高。流域人类活动是黄河氮营养盐含量增加的重要因素;流域降水减少、水土保持等导致的物理侵蚀作用减弱是黄河硅和磷减少的重要因素;自1986年后,流域泥沙减少导致河流溶解硅降低了约34%,这值得进一步关注。 相似文献
8.
为研究调水调沙对黄河下游溶解铀浓度及其入海通量的影响，于2014年调水调沙期间在黄河小浪底站及利津站进行了连续同步观测。结果发现，调水调沙期间，小浪底站溶解铀浓度的平均值在调水阶段为（4.28±0.33）μg/L，调沙阶段为（4.19±0.29）μg/L；利津站溶解铀浓度的平均值在调水阶段为（4.55±0.22）μg/L，调沙阶段为（4.87±0.40）μg/L。无论是调水阶段还是调沙阶段，利津站溶解铀浓度的平均值均比小浪底站高，且调沙阶段溶解铀增加量显著高于调水阶段。进一步分析讨论得出调水调沙期间氧化还原条件的变化以及悬浮颗粒物粒径的变化是影响黄河下游溶解铀化学行为的主要因素。2014年调水调沙的运行使得黄河下游利津站的溶解铀入海通量比河流正常输运状态下增加了8.3×102 kg；而2015年在只进行了调水的情况下，从小浪底站到利津站溶解铀通量减少了4.1×103 kg，说明不同模式下的调水调沙对溶解态铀入海通量的影响是不同的。由于在黄河口咸淡水混合带存在着悬浮颗粒物向水体释放溶解铀的现象，根据调水调沙期间悬浮颗粒物的增加量及溶解铀的释放系数估算得到2010年、2012年、2013年、2014年调水调沙期间在河口混合带释放的溶解铀分别为1.57×104 kg、0.739×104 kg、0.690×104 kg和8.25×102 kg，分别占各自年份全年溶解铀入海通量的15%、7.7%、5.3%和1.3%。 相似文献
9.
山东近海溶解态无机营养盐的分布特征研究 总被引：1，自引：0，他引：1
根据2006年8月、12月和2007年4月、10月山东近海海区4个航次海水中溶解无机营养盐等的调查资料,分析了该海域5种溶解无机营养盐(包括PO4-P,NO3-N,NO2-N,NH4-N,SiO3-Si)的平面分布和时空变化特征.结果表明,5种营养盐在胶州湾内出现高值,平面分布整体上呈现沿岸浓度高、外海浓度低的趋势;根据绝对限制和相对限制法则,春季和夏季P为限制因子,秋冬季营养盐结构发生变化,由缺P向缺Si转变;SiO3-Si浓度随季节变化逐渐增加,其他营养盐浓度在春季和夏季较低,秋季达到最大值.秋冬季溶解无机营养盐周日变化受潮汐影响明显. 相似文献
10.
《海洋通报》2021,(5)
长江口外潮汐混合和低盐度羽流形成的泥沙锋和羽状锋对浮游植物与环境因子的空间分布具有重要控制作用。本研究依据2019年夏季长江口及邻近海域典型断面叶绿素a (Chl-a)浓度和环境因子的调查结果,以锋面为边界,探讨了不同区域Chl-a浓度与环境因子的分布特征及相互关系,以期深入了解锋面的生态效应。结果表明,在泥沙锋以内的近岸区域,水体垂直混合均匀;受长江径流输入和泥沙锋"屏障"作用影响,总悬浮物(TSM)和营养盐浓度最高,其中TSM为220.0±275.3 mg/L,溶解无机氮(DIN)、溶解无机磷(DIP)和溶解硅酸盐(DSi)分别可以达到94.7±21.2μmol/L、0.85±0.33μmol/L和95.3±22.6μmol/L;高浓度TSM引起显著的光限制效应,导致Chl-a浓度较低(1.7±0.5μg/L)。在羽状锋以外的区域,出现垂直层化现象;表层海水的TSM和营养盐显著降低,其中TSM为5.1 mg/L,DIN、DIP和DSi分别为1.0μmol/L、0.03μmol/L和2.4μmol/L;Chl-a浓度受到营养盐供应不足的影响,浓度仅为0.2μg/L。高浓度的Chl-a (7.5±4.1μg/L)主要出现在泥沙锋和羽状锋之间的过渡区域,该区域营养盐得到长江径流与上升流的补充;同时,由于大量TSM在泥沙锋快速沉降,缓解了水体的光限制效应,有利于浮游植物的生长和积累。研究结果验证了泥沙锋和羽状锋对TSM与营养盐的重要控制作用,这对于理解长江口及邻近海域藻类灾害高发区的成因具有科学参考价值。 相似文献
11.
Anukul Buranapratheprat Tetsuo Yanagi Thanomsak Boonphakdee Pichan Sawangwong 《Journal of Oceanography》2002,58(4):557-564
Seasonal variations in freshwater, salt, dissolved inorganic phosphorus (DIP) and dissolved inorganic nitrogen (DIN) in the
Bangpakong estuary, Thailand were investigated by employing the database obtained in the National Research Council of Thailand
(NRCT)-Japan Society for the Promotion of Science (JSPS) cooperative project from 1994 to 1997. The results showed that variation
in interaction between coastal sea and river discharge played an important role in controlling the characteristics of the
water in the estuary. Residence time of fresh water was short in wet season and dry season, but it was long in the transition
period from season to season. DIP and DIN load depended on river discharge, while high peak concentrations were related to
loading and the long residence time in the transition period between dry and wet seasons. A strong eutrophic condition could
possibly occur when the concentration of DIP and DIN were high during the onset of the wet season from April to July. The
annual average of inorganic nutrient budgets indicated that the Bangpakong estuary is the internal source of 38.2 tons/month
DIP and the internal sink of 4.9 tons/month DIN.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
12.
Seasonal changes in nitrogen and phosphorus transport in the lower Changjiang River before the construction of the Three Gorges Dam 总被引：1，自引：0，他引：1
Shuiwang Duan Tao Liang Shen Zhang Lijun Wang Xiumei Zhang Xibao Chen 《Estuarine, Coastal and Shelf Science》2008
Water and sediment samples were collected at Datong from June 1998 to March 1999 to examine seasonal changes in the transports of nitrogen (N) and phosphorus (P) from the Changjiang River (Yangtze River) to the East China Sea (ECS). Dissolved inorganic nitrogen (DIN; dominated by nitrate) concentration exhibited small seasonality, and DIN flux was largely controlled by water discharge. Dissolved inorganic phosphorus (DIP) concentration was inversely correlated with water discharge, and DIP was evenly delivered throughout a year. The transports of DIN and DIP from the Changjiang River were consistent with seasonal changes in nutrient distributions and P limitation in the Changjiang Estuary and the adjacent ECS. Dissolved organic and particulate N (DON and PN) and P (DOP and PP) varied parallel to water discharge, and were dominantly transported during a summer flood. The fluxes of DOP and particulate bioavailable P (PBAP) were 2.5 and 4 times that of DIP during this period, respectively. PBAP accounted for 12–16% of total particulate P (PP), and was positively correlated with the summation of adsorbed P, Al–P and Fe–P. Ca–P, the major fraction of PP, increased with increasing percent of CaCO3. The remobilization of riverine DOP and PBAP likely accounted for the summer elevated primary production in DIP-depleted waters in the Changjiang Estuary and the adjacent ECS. The Changjiang River delivered approximately 6% of DIN (1459 × 106 kg), 1% of DIP (12 × 106 kg), and 2% of dissolved organic and particulate N and P to the totals of global rivers. The construction of the Three Gorges Dam might have substantially reduced the particulate nutrient loads, thereby augmenting P limitation in the Changjiang Estuary and ECS. 相似文献
13.
The Zhujiang River Estuary is becoming eutrophic due to the impact of anthropogenic activities in the past decades. To understand nutrient dynamics and fluxes to the Lingdingyang water via four outlets(Humen,Jiaomen, Hongqimen and Hengmen), we investigated the spatial distribution and seasonal variation of dissolved nutrients in the Zhujiang River Estuary, based on fourteen cruises conducted from March 2015 to October 2017,covering both wet(April to September) and dry(October to March next year)... 相似文献
14.
We examined the contribution of submarine groundwater discharge (SGD) to nutrient budgets in Hwasun Bay, Jeju Island, Korea in August 2009, October 2014, and May 2015. The concentrations of dissolved inorganic nitrogen (DIN) and dissolved inorganic phosphorus (DIP) in fresh groundwater were in the range of 285?716 μM and 2.3?3.2 μM, respectively, which were each 1?2 orders of magnitude higher than those in the bay seawater. The outer-bay seawater flowing into the bay was oligotrophic (2.9 ± 1.9 μM for DIN and 0.2 ± 0.3 μM for DIP). Nutrient budget calculations were performed for each season by accounting for submarine fresh groundwater discharge (SFGD) and water residence times. In August 2009 (DIN = 1.8 μM and DIN:DIP ratio = 4.6 for the outerbay water), DIN inputs from SFGD accounted for approximately 40% of the DIN inventory in the bay seawater. In October 2014 (DIN = 1.1 μM and DIP < 0.05 μM for the outer-bay water), DIP from SFGD accounted for approximately 100% of the DIP inventory in the bay seawater. In May 2015, mean concentrations of DIN and DIP in the bay seawater were 8.6 ± 12 μM and 0.11 ± 0.04 μM, respectively, with conservative behaviors in the bay seawater in association with excessive groundwater inputs. These results imply that SGD plays a critical but different role in nutrient budgets and stoichiometry in coastal waters off a volcanic island depending on open-ocean nutrient conditions. 相似文献
15.
近30a来长江口海域生态环境状况变化趋势分析 总被引：2，自引：1，他引：1
在过去近30a监测结果基础上,对长江口海域生态环境变化趋势进行了分析。结果表明,近30a来,长江口海域水体中无机氮和活性磷酸盐呈现上升的趋势,重金属(铜、铅、镉和总汞)在一定范围内波动;浮游生物的种类数年际变化较大,浮游植物中硅藻比例有所下降,甲藻所占比例有所上升,浮游动物中桡足类的比例下降。讨论了长江径流输沙量与环境因子之间的相关性,发现硅酸盐的含量与输沙量呈显著正相关,且硅酸盐的减少与海域硅藻比例的减少具有一定相关性。长江口及其邻近海域环境与生态状况有所下降,特别是本世纪以来,海域的主要污染物仍为无机氮和活性磷酸盐,生物状态基本稳定在一个较低的水平上,近年来虽偶有波动,但没有明显改善的趋势。 相似文献
16.
Nutrients,light and phytoplankton production in the shallow,tropical coastal waters of Bandon Bay,Southern Thailand 
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下载免费PDF全文 Takashi Yoshikawa Kosuke Tomizawa Yuki Okamoto Kazuya Watanabe Jintana Salaenoi Kenichi Hayashizaki Hisashi Kurokura Satoshi Ishikawa 《Marine Ecology》2017,38(6)
Phytoplankton primary production and its regulation by light and nutrient availability were investigated in the shallow, tropical coastal waters of Bandon Bay, Southern Thailand. The bay was meso‐eutrophicated and highly turbid, receiving river water discharge. Water column stratification was consistently weak during both rainy and dry seasons. Dissolved inorganic nitrogen (DIN) was higher off the river mouth than in the other regions, suggesting that river water discharge was a main source of DIN. By contrast, dissolved inorganic phosphorus (DIP) showed a significant negative correlation with total water depth, implying that regeneration around the sea floor was an important source of DIP. Surface DIN and DIP showed positive correlations with surface primary production (PP) and water column primary productivity (ΣPP*), respectively. The combined correlation and model analyses indicate that total water depth had an ambivalent influence on water column primary production (ΣPP); shallower water depth induced more active regeneration of nutrients, but it also caused higher turbidity and lower light availability as a result of enhanced resuspension of sediments. Furthermore, there was a vertical constraint for phytoplankton during the rainy season: total water depth tended to be shallower than euphotic zone depth. In conclusion, light limitation and vertical constraint owing to shallow water depth appear to be more important than nutrient limitation for water column primary production in Bandon Bay. 相似文献
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The spatial distribution of physico-chemical parameters(sea surface temperature(SST), p H, sea surface salinity(SSS), dissolved oxygen(DO) and Secchi depth) along with filterable nutrients(dissolved inorganic nitrate(DIN),dissolved inorganic phosphate(DIP) and reactive silicate(DSi)) are measured in the winter months of November,December, January and February for four consecutive years from 2009–2010 to 2012–2013 on the shallow continental shelf(20 m bathymetry) of the coastal waters(up to 18 km away from shoreline) of the northern Bay of Bengal(n Bo B) during the highest high tide(HHT) and lowest low tide(LLT) hours for the first time. The variability of the coastal biogeochemical environment is assessed during the HHT and LLT hours and for this purpose, seawater samples are collected from seven different locations of a transect in the coastal region. Physicochemical parameters(except SST) show significant difference in magnitude during the HHT and LLT hours respectively. p H, SSS and DO are found to increase in the HHT hours and vice-versa. The data reveal that during the LLT hours, a relative increase of freshwater input in the n Bo B can have elevated the nutrient concentration compared with that observed during the HHT hours. The ratio of nutrient concentration is found to deviate significantly from the Redfield ratio. The abundance of DIP is much higher compared with that of DIN and DSi.The anthropogenic sources of DIP from the upstream flow(especially the domestic effluent of several metropolises) can be mainly attributed behind such an observation. In order to characterize and establish the trend of such variation in such an important bio-climatic region, long-term and systematic ecosystem monitoring in the coastal water of the n Bo B northern Bay of Bengal should be carried out throughout the year. 相似文献