基于水污染物通量的小流域生态补水研究     

石成春 《地质灾害与环境保护》2011,22(2):99-102

为改善水质环境,对福建省龙江中下流进行补水效果实验.根据控制断面测得的水质浓度和流量数据,计算水污染物通量.使用该通量评估污染负荷,计算生态补水量.所得污染物通量良好地反映出流域污染状况,实验效果显著,河流水质达到了国家规定标准.  相似文献   

A primary study of the correlation between the net air-sea heat flux and the interannual variation of western North Pacific tropical cyclone track and intensity   总被引：3，自引：0，他引：3  

WU Liang  WEN Zhiping  HUANG Ronghui 《海洋学报(英文版)》2011,30(6):27-35

A singular value decomposition (SVD) analysis is carried out to reveal the relationship between the interannual variation of track and intensity of the western North Pacific tropical cyclones (WNPTCs) in the tropical cyclone (TC) active season (July-November) and the global net air-sea heat flux (Q net ) in the preceding season (April-June). For this purpose, a tropical cyclone track and intensity function (TIF) is defined by a combination of accumulated cyclone energy (ACE) index and a cyclone track densit...  相似文献   

Numerical study of M₂ internal tide generation and propagation in the Luzon Strait   总被引：1，自引：1，他引：0  

LI Huan  SONG Dan  CHEN Xueen  QIAN Hongbao  MU Lin  SONG Jun 《海洋学报(英文版)》2011,30(5):23-32

Based on the z-coordinate ocean model HAMSOM,we introduced the internal-tide viscosity term and applied the model to numerically investigate the M2 internal tide generation and propagation in the Luzon Strait (LS).The results show that (1) in the upper 250 m depth,at the thermocline,the maximum amplitude of the generated internal tides in the LS can reach 40 m;(2) the major internal tides are generated to the northwest of Itbayat Island,the southwest of Batan Island and the northwest of the Babuyan Islands;(3) during the propagation the baroclinic energy scattering and reflection is obvious,which exists under the effect of the specific topography in the South China Sea (SCS);(4) the westward-propagating internal tides are divided into two branches entering the SCS.While passing through 118 E,the major branch is divided into two branches again.The strongest internal tides in the LS are generated to the northwest of Itbayat Island and propagate northeastward to the Pacific.However,to the east of 122 E,most of the internal tides propagate southeastward to the Pacific as a beam.  相似文献   

Growth and grazing rate dynamics of major phytoplankton groups in an oligotrophic coastal site   总被引：1，自引：0，他引：1  

Andrés Gutiérrez-Rodríguez  Mikel Latasa  Renate Scharek  Ramon Massana  Gemma Vila  Josep M. Gasol 《Estuarine, Coastal and Shelf Science》2011

There has been more attention to phytoplankton dynamics in nutrient-rich waters than in oligotrophic ones thus requiring the need to study the dynamics and responses in oligotrophic waters. Accordingly, phytoplankton community in Blanes Bay was overall dominated by Prymnesiophyceae, remarkably constant throughout the year (31 ± 13% Total chlorophyll a, Tchl a) and Bacillariophyta with a more episodic appearance (20 ± 23% Tchl a). Prasinophyceae and Synechococcus contribution became substantial in winter (Prasinophyceae = 30% Tchl a) and summer (Synechococcus = 35% Tchl a). Phytoplankton growth and grazing mortality rates for major groups were estimated by dilution experiments in combination with high pressure liquid chromatography and flow cytometry carried out monthly over two years. Growth rates of total phytoplankton (range = 0.30–1.91 d⁻¹) were significantly higher in spring and summer (μ > 1.3 d⁻¹) than in autumn and winter (μ ∼ 0.65 d⁻¹) and showed a weak dependence on temperature but a significant positive correlation with day length. Microzooplankton grazing (range = 0.03–1.4 d⁻¹) was closely coupled to phytoplankton growth. Grazing represented the main process for loss of phytoplankton, removing 60 ± 34% (±SD) of daily primary production and 70 ± 48% of Tchl a stock. Chla synthesis was highest during the Bacillarophyceae-dominated spring bloom (Chl a_synt = 2.3 ± 1.6 μg Chl a L⁻¹ d⁻¹) and lowest during the following post-bloom conditions dominated by Prymnesiophyceae (Chl a_synt = 0.23 ± 0.08 μg Chl a L⁻¹ d⁻¹). This variability was smoothed when expressed in carbon equivalents mainly due to the opposite dynamics of C:chl a (range = 11–135) and chl a concentration (range = 0.07–2.0 μg chl a L⁻¹). Bacillariophyta and Synechococcus contribution to C fluxes was higher than to biomass because of their fast-growth rate. The opposite was true for Prymnesiophyceae.  相似文献   

大洋海区海-气CO_2通量单参数遥感算法的适用性检验   总被引：1，自引：0，他引：1  

王郝京 《台湾海峡》2011,30(2):286-291

利用卫星遥感技术的优势,基于LDEO数据库的全球海表二氧化碳分压（PCO2）及海表温度（SST）等实测数据,初步建立东太平洋海区PCO2与SST的单参数经验算法,并采用相同区域的独立实测数据检验.结果表明,单参数算法在寡营养大洋海区具有良好的适用性,反演值与实测值之间的均方根误差（RMS）为0.51 Pa（1 Pa=9.869μatm）,由此估算出2003年6月该海域CO2通量为-1.4 mmol/（m2.d）,与实测估算的碳通量基本相符,能够很好地反映出海区CO2源汇特征.将该遥感算法运用到西大西洋海域（15°~25°N,60°~75°W）,反演值与实测值之间均方根误差（RMS）为0.69 Pa.检验结果表明,在寡营养大洋海区,单参数遥感算法具有一定的适用性,在受相似因子调控的同纬度海区可以使用同一遥感算法.  相似文献   

Interannual variability in vertical export in the Ross Sea: Magnitude, composition, and environmental correlates     

Walker O. Smith Jr  Amy R. Shields  Jennifer C. Dreyer  Vernon Asper 《Deep Sea Research Part I: Oceanographic Research Papers》2011,58(2):147-159

The vertical flux of particulate matter from the surface of the Ross Sea, Antarctica, has been suggested as being large, with substantial seasonal and spatial variations. We conducted a study in which vertical flux was quantified using sediment traps deployed at 200 m and compared to estimates calculated from one-dimensional budgets of nutrients (nitrogen and silicon). Estimates of flux were collected at two locations in the southern Ross Sea from late December to early February during four years: 2001-2002, 2003-2004, 2004-2005, and 2005-2006. Phytoplankton biomass and vertical flux varied substantially seasonally and spatially between the two sites, and among years. The greatest flux was observed in 2001-2002, with a short-term maximum organic carbon flux of 3.13 mmol m⁻² d⁻¹, and the summer mean organic carbon flux equal to 0.93 mmol m⁻² d⁻¹. In contrast, the mean carbon flux at the same site in 2003-2004 was over an order of magnitude less, averaging 0.19 mmol m⁻² d⁻¹, despite the fact that productivity in that year was substantially greater. In 2005-206 the contribution of fecal pellets to flux was smallest among all years, and the pellet contribution ranged from <1 to more than 50% of organic flux. As the moorings also had surface layer fluorometers, the relationship between surface biomass and sediment trap flux was compared. Temporal lags between surface fluorescence and flux at 200 m maxima in 2003-2004 and 2004-2005 ranged from two to six days; however, in 2005-2006 the temporal offset between biomass and flux was much longer, ranging from 11 to 27 days, suggesting that fecal pellet production appeared to increase the coupling between flux and surface production. Estimates of export from the upper 200 m based on one-dimensional nutrient budgets were greater than those recorded by the sediment traps. Nutrient budgets also indicated that siliceous production averaged ca. 40% of the total annual production. The variations observed in the flux of biogenic matter to depth in the Ross Sea are large, appear to reflect different forcing among years, and at present are not adequately understood. However, such variability needs to be both understood and represented in biogeochemical models to accurately assess and predict the effects of climate change on biogeochemical cycles.  相似文献   

First observations of jelly-falls at the seafloor in a deep-sea fjord     

Andrew K. Sweetman  Annelise Chapman 《Deep Sea Research Part I: Oceanographic Research Papers》2011,58(12):1206-1211

Faunal communities at the deep-sea floor mainly rely on the downward transport of particulate organic material for energy, which can come in many forms, ranging from phytodetritus to whale carcasses. Recently, studies have shown that the deep-sea floor may also be subsidized by fluxes of gelatinous material to the benthos. The deep-sea scyphozoan medusa Periphylla periphylla is common in many deep-sea fjords in Norway and recent investigations in Lurefjorden in western Norway suggest that the biomass of this jellyfish currently exceeds 50000 t here. To quantify the presence of dead P. periphylla jellyfish falls (hereafter termed jelly-falls) at the deep seafloor and the standing stock of carbon (C) and nitrogen (N) deposited on the seafloor by this species, we made photographic transects of the seafloor, using a ‘Yo-Yo’ camera system during an opportunistic sampling campaign in March 2011. Of 218 seafloor photographs taken, jelly-falls were present in five, which resulted in a total jelly-fall abundance of 1×10^-2 jelly-falls m⁻² over the entire area surveyed. Summed over the entire area of seafloor photographed, 1×10^-2 jelly-falls m⁻² was equivalent to a C- and N-biomass of 13 mg C m⁻² and 2 mg N m⁻². The contribution of each jelly-fall to the C- and N-amount of the sediment in the immediate vicinity of each fall (i.e. to sediment in each 3.02 m² image in which jelly-falls were observed) was estimated to be 568±84 mg C m⁻² and 88±13 mg N m⁻². The only megafaunal taxon observed around or on top of the jelly-falls was caridean shrimp (14±5 individuals jelly-fall⁻¹), and shrimp abundance was significantly greater in photographs in which a jelly-fall was found (14±5 individuals image⁻¹) compared to photographs in which no jelly-falls were observed (1.4±0.7 individuals image⁻¹). These observations indicate that jelly-falls in this fjord can enhance the sedimentary C- and N-amount at the deep-sea floor and may provide nutrition to benthic and demersal faunas in this environment. However, organic enrichment from the jelly-falls found in this single sampling event and associated disturbance was highly localized.  相似文献   

单点高频地波雷达资料估算潮能耗散的方法   总被引：1，自引：0，他引：1  

毛华斌  陈举  邱春华  练树民 《热带海洋学报》2011,(6)

使用嵊泗站所布设的地波雷达观测获取的径向流数据,以及嵊泗、芦潮港、岱山3个潮汐观测站水位资料,采用两点近似投影方法反演流场全矢量流速,并用T-Tide程序计算调和常数,分别计算O1、K1、M2、S2各分潮流速场及迟角场,并计算各点上的潮能通量及潮能耗散,得到嵊泗岛以西杭州湾口区域潮能耗散同地形存在良好对应关系,充分证明了采用地波雷达观测数据进行潮能耗散计算这一方法的可行性,供相关工作者作进一步研究和讨论.  相似文献   

2005-2006年大亚湾大鹏澳养殖区甲藻孢囊通量的沉积捕捉器研究     

王朝晖  曹宇  张玉娟 《热带海洋学报》2011,30(1)

于2005年3月至2006年4月在大亚湾的大鹏澳养殖区采用沉积物捕捉器,对甲藻孢囊形成和水温、盐度、营养盐含量等环境因子进行了周年调查,探索该区孢囊形成特征及其与环境因子的关系.在一年的沉积物捕捉器研究中,共分析鉴定出27种甲藻孢囊类型,锥状斯氏藻Scrippsiella trochoidea孢囊为该区最优势孢囊类群,从孢囊的组成显示了该区的污染是以养殖和生活污染为主.孢囊形成没有明显的季节分布特征,两个站年平均为1.07×10<'5>cysts·(m<'2>·d)<'-1>.高、低温都能在一定程度上促进孢囊的生成,氮限制对孢囊的形成具有明显促进作用.首次发现亚历山大藻Alexandrium孢囊在冬季形成的高峰,最高值达4.26×10<'5>cysts·(m<'2>·d)<'-1>.这说明核电站温排水冬季高水温对大亚湾生态环境有较大的影响.  相似文献   

Response and recovery of the Comanche carbonate platform surrounding multiple Cretaceous oceanic anoxic events,northern Gulf of Mexico     

《Cretaceous Research》2015

The ubiquity of carbonate platforms throughout the Cretaceous Period is recognized as a product of high eustatic sea-level and a distinct climatic optimum induced by rapid sea-floor spreading and elevated levels of atmospheric carbon-dioxide. Notably, a series of global oceanic anoxic events (OAEs) punctuate this time-interval and mark periods of significantly reduced free oxygen in the world's oceans. The best records of these events are often from one-dimensional shelf or basin sections where only abrupt shifts between oxygenated carbonates and anoxic shales are recorded. The Comanche Platform of central Texas provides a unique opportunity to study these events within a well-constrained stratigraphic framework in which their up-dip and down-dip sedimentologic effects can be observed and the recovery of the platform to equilibrium states can be timed and understood. Stable isotope data from whole cores in middle Hauterivian through lower Campanian mixed carbonate-siliciclastic strata are used to construct a 52-myr carbon isotope reference profile for the northern Gulf of Mexico. Correlation of this composite curve to numerous global reference profiles permits identification of several anoxic events and allows their impact on platform architecture and facies distribution to be documented. Oceanic anoxic events 1a, 1b, 1d, and 2 occurred immediately before, after, or during shale deposition in the Pine Island Member, Bexar Member, Del Rio Formation, and Eagle Ford Group, respectively. Oceanic anoxic event 3 corresponds to deposition of the Austin Chalk Group. Platform drowning on three occasions more closely coincided with globally recognized anoxic sub-events such as the Fallot, Albian-Cenomanian, and Mid-Cenomanian events. This illustrates that the specific anoxic event most affecting a given carbonate platform varied globally as a function of regional oceanographic circumstances.Using chemo- and sequence-stratigraphic observations, a four-stage model is proposed to describe the changing facies patterns, fauna, sedimentation accumulation rates, platform architectures, and relative sea-level trends of transgressive-regressive composite sequences that developed in response to global carbon-cycle perturbations. The four phases of platform evolution include the equilibrium, crisis, anoxic, and recovery stages. The equilibrium stage is characterized by progradational shelf geometries and coral-rudist phototrophic faunal assemblages. Similar phototrophic fauna typify the crisis stage; however, incipient biocalcification crises of this phase led to retrogradational shelf morphologies, transgressive facies patterns, and increased clay mineral proportions. Anoxic stages of the Comanche Platform were coincident with back-ground deposition of organic-rich shale on drowned shelves and heterotrophic fauna dominated by oysters or coccolithophorids. Eustatic peaks of this stage were of moderate amplitude (∼30 m), yet relative sea-level rises were greatly enhanced by reduced sedimentation rates. In the recovery stage, heterotrophic carbonate factories re-established at the shoreline as progradational ramp systems and sediment accumulation rates slowly increased as dysoxia diminished. Full recovery to equilibrium conditions may or may not have followed. Geochemical and stratigraphic trends present in the four stages are consistent with increased volcanism along mid-ocean ridges and in large-igneous provinces as primary drivers of Cretaceous OAEs and the resulting transgressive-regressive composite sequences.  相似文献