太湖及其主要入湖河流沉积磷形态分布研究

选择了我国第三大浅水湖泊--太湖及其主要入湖河流进行沉积磷形态的连续提取研究.太湖湖区沉积磷中不稳态磷(LP)及铝结合态磷(Al-P)含量很低,其余形态磷为铁结合态磷(Fe-P)＜钙结合态磷(Ca-P)＜有机磷(Org-P).河流沉积物中有机磷的相对含量高于湖泊沉积物,绝对含量平均值约为湖泊沉积物的3.9倍,铁结合态磷的绝对含量约为湖泊沉积物的3/4,湖区沉积物Fe-P含量与水体中PO3-4-、Chla呈显著正相关关系,同时与间隙水的氧化性呈显著负相关关系.太湖各湖区沉积物的磷形态表现为空间差异较大,活性组分的差异性要大于活性较差的组分.总的来说北部湖区沉积物中Fe-P和Org-P含量高于其他湖区,这与太湖北部湖区水体高营养级和藻类爆发关系密切.湖区沉积磷的垂直分布规律较复杂,既有随深度增加的,也有随深度降低的,河流沉积物同样如此.这与太湖及河流生态条件、污染物排放以及沉积动力学条件不同有关.     

太湖入湖河道沉积物中生物利用磷和营养水平分析

为了解太湖入湖河道的营养状况,研究了太湖西部河流沉积物生物利用磷的组成与分布。研究结果显示,北部沉积物中营养元素较高,南部较低;沉积物中生物利用磷的含量次序为藻类可利用磷(AAP)>NaHCO3提取磷(OLP)>水溶性磷(WSP)>易解吸磷(RDP),其中AAP是重要的生物利用磷,AAP的比例越高,富营养化程度越高。AAP与营养元素的相关性在不同区域河道有所不同,北部河道与总氮(TN)、总磷(TP)相关性较好,中部和南部河道与沉积物有机质总量(TOM)相关性较好。沉积物的生物利用磷受不同污染源影响较大。对比河道沉积物与湖泊沉积物的特征,发现湖泊沉积物中生物利用磷(BAP)/总磷(TP)、藻类可利用磷(AAP)/总磷(TP)都高于河道沉积物,表明湖泊沉积物中的磷更容易被植物吸收。     

南四湖及主要入湖河流沉积物中磷的赋存形态研究

应用沉积物磷形态SMT提取方法,分析了南四湖及主要入湖河流丰水季节表层沉积物、独山湖及微山湖区沉积岩芯中磷的含量及形态组成变化,研究了磷的埋藏演化过程与人为污染特征.结果表明,老运河表层沉积物中磷的含量最高,为13068.3 mg/kg,以OP及NaOH-P为主,其富集系数分别为6.5和9.0,主要是与来自济宁市的废水污染有关.其余表层沉积物以HCl-P为主;受人为污染的影响,NaOH-P、OP产生一定程度的富集,其富集系数分别为1.0.3.7、1.3～6.0;部分沉积物中高含量的有机质加重了OP的富集.独山湖及微山湖沉积岩芯中以HCl-P和OP为主;20世纪60年代末期以来,随着湖泊生产力的提高及早期成岩过程中有机质的矿化分解,独山湖及微山湖沉积岩芯中TOC含量自下而上呈指数增加,这也导致了沉积物中OP的增加;独山湖及微山湖沉积岩芯6～0 cm和5～0 cm较高的OP及NaOH-P含量,指示了20世纪80年代中期以来磷的人为污染过程.     

Phosphorus fractions in sediment profiles and their potential contributions to eutrophication in Dianchi Lake

Dianchi Lake is a eutrophic lake in southwestern China. Sediment and the bottom water samples were taken from six sites in the east, west, south, north and center of the lake, respectively, in December 2002. Total phosphorus (TP) concentrations in sediments were high and reached a maximum value of 6.66 g/kg. There was a soluble reactive phosphorus (SRP) concentration gradient at the sediment–water interface. In the present study, sediment P was divided into loosely adsorbed P (NH₄Cl-P), redox-sensitive P (BD-P), metal oxides bound P (NaOH-P), calcium bound P (HCl-P), and organic P (Org-P). At three of the six sites selected, the concentrations of different P forms in sediments followed the order: NaOH-P, Org-P>HCl-P>BD-P>NH₄Cl-P in the profile, and in the southern lake the order was HCl-P>NaOH-P, Org-P>BD-P>NH₄Cl-P in the top 15 cm layers of the sediments. The sediment profiles showed that different forms of P had an increasing trend upward toward the sediment surface. There is a considerable potential for release from the sediment into the overlying water and sediment P could be the dominant factor determining the trophic status of the lake if the external load is reduced. An erratum to this article can be found at     

Geochemical records of the sediments and their significance in Dongping Lake Area,the lower reach of Yellow River,North China

Dongping Lake area, located in the lower reaches of Yellow River, is an ideal place to study the changes of modern river and lake sedimentary environment. The sediment samples of Dawen River, Yellow River, and Dongping Lake were collected, and the major elements, trace elements and organic matter geochemical composition of the samples were analyzed. Cluster analysis, characteristic element ratio method and graphic method were used to explore the geochemical characteristics of sediments and their environmental implication. The results show that the contents of SiO_2, Na_2O, TiO_2 and Zr in sediments of Dawen River and Yellow River are relatively high, and the contents of iron and manganese oxides, organic matter, CaO, P_2O_5 and Sr in lake sediments are relatively high. That reveals the differences of sedimentary environments between the rivers and the lake. The contents of Sr and Zr in Dawen River are affected by the rapid migration of clastic materials in the upstream carbonate source area during the flood season; the δCe,ΣREE and REE's ratios in the sediments of the Yellow River reflect the influence of the Loess source; and the distribution of elements changes along the flow direction during the flood season. The characteristics of p H, element composition and LREE HREE fractionation of the lake sediments indicate that the sediment source is complex, and the lake environment is affected by the flood season. The study shows that the geochemical content and its variation characteristics of sediments effectively reveal the sedimentary environment, material composition and characteristics of flood season of rivers and the lake in the study area.     

内蒙古岱海表层沉积物中孢粉的分布及来源

岱海位于半干旱区东部边缘及东亚夏季风的尾闾区，生态环境体系脆弱，气候和环境变化敏感，是研究环境变化的理想地区。65个湖泊表层及入湖河流冲积物样品的孢粉分析揭示了岱海表层孢粉沉积特征及孢粉来源。岱海表层孢粉主要来源于区域性植被的孢粉，其总体特征反映了区域植被的组成，但不同部位孢粉组合的差异反映了湖滨当地植被的变化。受沉积环境的影响，岱海湖区孢粉浓度总体上要低于入湖河流孢粉浓度，湖区中部孢粉浓度最高。岱海孢粉以河流携带的为主，同时受风力传播的影响。蒿、藜科、桦、虎榛子等花粉和蕨类孢子以河流搬运的为主，松、禾本科及莎草科花粉可能还受风力传播的影响。一些仅在个别样品中出现且百分比很低的花粉类型如豆科、十字花科等还有可能是昆虫、鸟类或人类活动携带而来。     

浅水湖泊沉积物中磷的地球化学特征

对太湖不同污染状况和生态系统状况的湖区沉积物中磷的地球化学形态及其分布进行了研究。结果发现,沉积物的理化性质和磷的化学形态一般都在表层下深5～15cm发生明显的转折;草型湖区、藻型湖区、开阔湖面的大湖区沉积物的理化性质、间隙水中的磷浓度及沉积物中磷的形态存在较大的差异。东太湖沉积物间隙水磷浓度和交换态磷含量都显著低于其他湖区;风浪扰动相对剧烈的开阔湖面湖区沉积物中磷的沉积规律也不同于梅梁湾藻型湖区和东太湖草型湖区。研究表明,浅水湖泊中水生生物状况、风浪扰动状况对沉积物中磷的地球化学行为有至关重要的影响。     

中国现代网状河流沉积特征和沉积模式

中国境内的许多河流发育有网状河段,从长江、黑龙江、珠江等这样的大型河流到嫩江、赣江等中小型河流都有。依据这些网状河的地理和构造背景的不同,可以把它们划分为:平原网状河流、山谷网状河流、入湖三角洲平原网状河流和入海三角洲平原网状河流四大类型。作者通过实地挖掘探槽、密集采样,对嫩江齐齐哈尔平原网状河段、赣江入湖三角洲平原网状河段、珠江入海三角洲平原网状河段沉积特征进行了详细描述和研究,并建立了网状河的沉积模式,探讨了网状河的成因。认为网状河流体系的发育不受气候和地理位置的限制,低坡降是形成网状河的必要条件,相对稳定的网状河道不同于曲流河和辫状河,湿地环境是网状河流体系中最发育的地貌单元,堤岸植被繁茂、粘结性高是河道稳定的重要因素,与曲流河和辫状河相比,网状河出现的几率较低。     

The research of phosphorus of Xiangxi River nearby the Three Gorges, China

The Xiangxi River is the first middling tributary of the Changjiang River near the Three Gorges Dam. The River is subject to phosphorus pollution mainly from industrial wastewater. As the water quality of the Xiangxi River could directly influence the water quality of the Three Gorges Reservoir, the research on phosphorus levels and its change in the sediment profile of the Xiangxi River could provide useful information in the dynamic changes in the system, thereby offering options for mitigative measures. Water and sediment samples from lower reaches of Xiangxi River were collected and the different forms of phosphorus in sediments of the Xiangxi River were studied. The concentrations of total phosphorus in sediment ranged from 757.67 to 1438.54 mg/kg. Inorganic phosphorus concentrations ranged from 684.63 to 1055.58 mg/kg. Phosphorus contamination was serious in some parts of the Xiangxi River. With an average concentration of 635.17 mg/kg, calcium-bound phosphorus is the main form among different inorganic phosphorus forms. Labile phosphorus and iron/aluminum-bound phosphorus measured 3.40, 0.05and 35.28 mg/kg, respectively. The mobilization potential of phosphorus of sediments was studied through adsorption and release experiments. The equilibrium concentration of phosphorus adsorption and release was around 0.1 mg/L. The initial concentrations of phosphorus in the overlying water and the sediments have obvious effect on phosphorus mobilization potential. In addition, the release rate of phosphorus in sediment increased with water depth.     

中国东部箕状断陷湖盆扇三角洲与辫状河三角洲对比研究

中国东部箕状断陷湖盆短轴方向,常常发育扇三角洲和辫状河三角洲,二者均可形成良好的油气储集体,但在岩芯以及地球物理资料的识别上常常容易混淆。通过对它们沉积特征、地球物理资料特征、含油气性和控制因素的对比研究和分析认为:扇三角洲是陡坡带冲积扇直接入湖形成,地震反射特征为楔形前积,沉积物成分成熟度和结构成熟度均低于辫状河三角洲,沉积特征反映重力流和牵引流双重作用;辫状河三角洲是缓坡带辫状河入湖形成的三角洲,向湖盆方向推进较远,地震反射特征为叠瓦前积,沉积特征反映牵引流作用。扇三角洲易形成构造-岩性油气藏和岩性油气藏,有利相带为扇三角洲前缘水下分流河道、席状砂以及前扇三角洲容易发育的滑塌浊积扇;辫状河三角洲易形成地层-岩性油气藏和岩性油气藏,有利相带为辫状河三角洲平原辫状分流河道,辫状河三角洲前缘水下分流河道、河口坝、席状砂以及半深湖中的浊积岩体。古气候变化、构造-古地貌以及湖平面变化速率三者共同作用于扇三角洲和辫状河三角洲的沉积特征,其中构造-古地貌是主控因素。结合二者沉积特征差异,建立了中国东部箕状断陷湖盆扇三角洲和辫状河三角洲沉积模式图,以期能对相似构造背景下扇三角洲和辫状河三角洲的分析与研究提供一定的指导作用。     

湖平面升降对浅水三角洲影响的沉积数值模拟实验

湖平面升降对三角洲沉积体的发育具有重要影响,前人对此做了相关研究,但对于其形成过程缺乏定量分析.利用水动力数值模拟的方法正演模拟了湖平面变化情况下浅水三角洲的形成过程并精确分析了其演化规律.根据现代河流三角洲的水动力特征,设计了水动力及泥沙条件,采用Delft3D模拟了湖平面上升和湖平面下降两种沉积过程.通过对浅水三角洲的模拟分析得到湖平面的升降对沉积体的形成与分布、河道的演化具有重要影响,结合平面和剖面分析发现沉积体的多期叠置现象.研究结果表明湖平面控制着沉积体的进退及其沉积特征,且利用水动力数值模拟方法可较好地揭示湖平面变化下浅水三角洲的演化过程.      

Importance of terrestrially-derived,particulate phosphorus to phosphorus dynamics in a west coast estuary

Allochthonous inputs of suspended particulate matter from freshwater environments to estuaries influence nutrient cycling and ecosystem metabolism. Contributions of different biogeochemical reactions to phosphorus dynamics in Tomales Bay, California, were determined by measuring dissolved inorganic phosphorus exchange between water and suspended particulate matter in response to changes in salinity, pH, and sediment redox. In serum bottle incubations of suspended particulate matter collected from the major tributary to the bay, dissolved inorganic phosphorus release increased with salinity during the initial 8 h; between 1–3 d, however, rates of release were similar among treatments of 0 psu, 16 psu, 24 psu, and 32 psu. Release was variable over the pH range 4–8.5, but dissolved inorganic phosphorus releases from sediments incubated for 24 h at the pH of fresh water (7.3) and seawater (8.1) were similarly small. Under oxidizing conditions, dissolved inorganic phosphorus release was small or dissolved inorganic phosphorus was taken up by particulate matter with total P content <50 μmoles P g^?1; release was greater from suspended particulate matter with total phosphorus content >50 μmoles P g^?1. In contrast, under reducing conditions maintained by addition of free sulfide (HS^?), dissolved inorganic phosphorus was released from particles at all concentrations of total phosphorus in suspended particulate matter, presumably from the reduction of iron oxides. Since extrapolated dissolved inorganic phosphorus release from this abiotic source can account for only 12.5% of the total dissolved inorganic phosphorus flux from Tomales Bay sediments, we conclude most release from particles is due to organic matter oxidation that occurs after estuarine deposition. The abiotic, sedimentary flux of dissolved inorganic phosphorus, however, could contribute up to 30% of the observed net export of dissolved inorganic phosphorus from the entire estuary.     

川西坳陷上侏罗统遂宁组洪水-漫湖沉积特征

利用岩芯、薄片鉴定、粒度分析、录井及测井解释等资料和手段,对四川盆地川西坳陷上侏罗统遂宁组沉积特征进行研究。结果表明,川西坳陷在遂宁组沉积时期处于稳定坳陷阶段,沉积作用明显受周期性洪水注入影响,形成“洪水-漫湖”沉积体系。“洪水-漫湖”沉积主要发育冲积扇、曲流河、曲流河三角洲和湖泊4个沉积相和若干个沉积微相,其沉积具有以下特征:①频繁的湖平面升降,形成砂泥互层的地层叠加样式;②缺乏大面积分布的半深湖-深湖沉积;③河流相为主要的沉积类型;④湖盆具有多物源、多期漫湖、满盆含砂的沉积特点。“洪水-漫湖”是川西坳陷遂宁组一种沉积充填新模式,对指导油气勘探具有重要的理论和实践意义。     

典型内陆湖泊沉积物氮、磷和重金属分布特征及生态风险评价——以武汉市武湖为例

城市内陆型湖泊湿地对城市生态系统具有重要的作用。以武汉市武湖为例,采用数理统计、营养盐指数、地累积指数和潜在生态风险指数等方法,对武湖表层沉积物中的氮、磷、有机质和重金属的平面分布特征、影响因素、富集污染程度、生态风险进行评价。结果表明: 武湖西北部表层沉积物中总氮、总磷和有机质的含量明显高于东南部,武湖周边地表径流和农田是营养元素的主要来源,旱地较水田有利于沉积物中总磷的富集; 武湖沉积物中有机质为内源水生植物和外源陆生植物的混合来源,与总氮具显著正相关关系; 沉积物中重金属含量总体较低,局部呈现高镉,平面上总体北部高于南部; 沉积物中重金属富集程度和潜在风险较低,局部地区镉和铅为轻微富集,镉和汞具中等潜在风险; 沉积物的潜在生态风险为低至中等,潜在生态风险与沉积物中镉的分布高度一致。     

Distribution and sources of phosphorus in tidal river sediments in the Washington, DC, Area

 Sediments in the rivers and basins around Washington, DC, have high concentrations of phosphorus, which, based on geographic distributions, is largely derived from urban runoff and municipal sewage. Dissolved-particulate phosphate exchange reactions and biological uptake of dissolved phosphorus from the water column may be an added source of phosphorus to the sediments. Concentrations of total sedimentary phosphorus ranged from 24 to 56 μm P/g-dw, and were highest in areas near combined sewer outfalls. As a part of this study, sedimentary phosphorus was fractionated into Fe-P, Ca-P, Al-P, and organic phases using a selective-sequential leaching procedure. The distribution of the phases in all sediments analyzed follow the order , Fe-P>Ca-P>Al-P. Spatial variations in the amounts of phosphorus in the different phases is related to the sources of phosphorus to the area. The proportions of occluded Al-P and organic P are 10–20% of the total P, respectively. This suggests that phosphorus from natural sources is small compared to anthropogenic inputs in this area. The high leachable Fe-P and Ca-P in these sediments might contribute a substantial amount of P to the water column under conditions of remobilization. Received: 20 February 1996 · Accepted: 2 April 1996     

鄂尔多斯盆地中南部中侏罗世延安期沉积体系及岩相古地理演化

依据新的地层划分方案及大量钻井、露头及岩芯资料，详细研究了鄂尔多斯中南部地区中侏罗世延安期沉积体系、岩相古地理特征及演化。认为延10期为冲积扇－河流沉积体系，低弯度砾砂质河道发育，盆地内存在多个古地貌高地，4条水系汇入甘陕主河；延9至延6期为多源河湖三角洲沉积体系，具大三角洲平原、中三角洲前缘和小前三角洲的特征，三角洲平原及前缘的位置不断向湖区推进；延4＋5期为网状河－残余湖泊沉积体系，湖泊淤塞，水体变浅。延9至延4＋5期网状砂质河道发育，西部地区广泛发育平原沼泽煤系沉积。     

Spatial characters of nutrients in Wujiangdu Reservoir in karst river,SW China

A preliminary assessment of the Wujiangdu Reservoir examined nutrient distribution and transport. Water samples were collected in the summer (July) of 2004, during the high-flow season. Inorganic nutrients (N, P, Si) and chlorophyll a (chl a) concentrations of the Wujiangdu Reservoir and its inflow rivers were analyzed. Other water parameters (dissolved oxygen, pH, temperature, and electrical conductivity) were measured as well. The results show gradually decreasing concentrations of NO₃ ^?-N and dissolved silicate in the surface water moving downstream to the dam of the Wujiangdu Reservoir. Additionally, soluble reactive phosphorus concentrations measured very low, with most falling below the sensitivity threshold of the method used in surface waters. Particulate phosphorus and NO₃ ^?-N were the predominant species of phosphorus and nitrogen in the reservoir, respectively. The concentration of nutrients in the Yeji River was the largest of all inflow rivers. The maximum concentration of chl a was found near the dam. These results reflect upstream conditions similar to that of a river, and reservoir conditions near the dam similar to that of a natural lake system.     

Sediment salt-load in the St Lucia Estuary during the severe drought of 2002–2006

The purpose of this study was to determine whether there was a sufficiently high residual salt load in the dry sediments of the St Lucia Estuary to cause salinity problems should it later fill up with either freshwater or seawater. The estuary lakes have suffered the effects of a severe drought since 2002 with the result that many areas were dry, and the salinity of the residual water varied between 4 psu and up to five times that of seawater. Measurements of the salts content in the sediments to a depth of 20 cm showed that more than 2 million tonnes of salt was held in this layer of the sediment in 2006. Recent management of the estuary (since 1970) has ensured that the mouth was not artificially opened. This was to prevent the inflow of seawater, with its salts, that would otherwise enter while the drought was in place. The results of the sediment salinity data showed that if the drought had been broken and the lake area filled with rain and river water, the resulting salinity would be about 6 psu. In March 2007, Cyclone Gamede in the Indian Ocean off the east coast of South Africa produced a wave climate at sea that resulted in the mouth breaching; thus introducing an estimated 12 million tonnes of salts. The high salinity in the system resulting from this breach is expected to have an adverse effect on the ecology of the system, whereas the residual salinity in the sediments would not have caused an environmental problem. If the estuary and lake system were to fill completely with seawater, the residual salts together with seawater will raise the salinity to an initial value higher than 40 psu, which will have the effect of suppressing much of the important submerged vegetation that is vital for sustaining juvenile fish in the system. Many of the large fauna will also suffer from a shortage of freshwater.     

湖芯沉积物揭示的末次冰消开始时期 普莫雍错湖区环境变化*

文章讨论了末次冰消开始时期青藏高原南部普莫雍错湖芯沉积反映的环境暖湿化以及原因。通过对现代湖泊和周边河流水文状况调查,发现流域内发育众多冰川,冰川融水构成维持湖面稳定的重要来源;湖面以及湖泊沉积环境的变化与冰川融水以及相应的温度改变具有密切的联系。利用湖泊沉积岩芯PM-1孔,通过加速器¹⁴ C测年和粒度、元素、碳酸盐含量、总有机碳以及有机碳同位素、总氮、分子标志化合物、孢粉等环境指标的分析,发现在16.4~15.4cal.kaB.P.有大量流水进入湖泊,使湖面扩大,湖水加深;流域地表产生大量有机碎屑,并被流水带入湖泊进行沉积;流域内的喜湿植被得以发展。该时段湖泊扩张、陆源植被发展的原因一方面得益于冰期过后气候向温暖湿润方向转化,另一方面温度上升带来大量冰川融水则可能具有更加重要的影响,对于深入理解当前青藏高原冰川普遍退缩和一些湖泊的水面上涨具有重要的参考价值。     

Spatial variations and distributions of phosphorus and nitrogen in bottom sediments from a typical north-temperate lake,China

Concentrations and vertical distributions of total nitrogen (TN), total phosphorus (TP) and their different forms in sediments obtained from nine locations of Lake Dalinouer in September 2008 were analyzed. The results demonstrated that TP in surface sediments ranged from 0.493 to 0.904 g/kg, and inorganic phosphorus was the main fraction of total phosphorus, ranging from 335 to 738 mg/kg. Simultaneously, the autogenetic calcium phosphorus (ACa-P) was the main fraction of inorganic phosphorus, ranging from 145.4 to 543.2 mg/kg. Vertical distribution of different phosphorus forms in different sediment cores was distinguishing, and most of them tended to increase toward the surface sediment, indicated that the phosphorus concentration was related to the humanity with a certain extent. The relationships between TP and occluded phosphorus and ACa-P were significant. Nitrogen in the sediment was composed mainly of organic nitrogen, accounting for grater than 80 % of TN. NO₃ ^?-N was the dominate fraction of inorganic nitrogen in the surface sediment, ranging between 51 and 346 mg/kg (151.1 ± 104.4 mg/kg), and accounting for between 2.2 and 17.7 % of total sediment nitrogen (6.2 ± 5.6 %). The ratio of organic carbon and TN in sediment was in range of 6.0–25.8 and presented a tendency of lake centre >lake sides, indicating that nitrogen accumulated in the sediments from lake sides came mainly from terrestrial source and nitrogen was mainly autogenetic in lake centre. Ratio of N:P in all sampling sites was below 14, indicated that N was the limiting nutrient for algal growth in this lake.