Atmospheric Correction of SeaWiFS Data for the Retrieval of Suspended Sediment in East China Coastal Waters     

廖迎娣  张玮P．Y．Deschamps 《中国海洋工程》2005,19(2):225-234

The data of SeaWiFS (Sea-Viewing Wide Field-of-View Sensor), installed on SeaStar, has been used to generate SSC (suspended sediment concentration) of complex and turbid coastal waters in China. In view of the problems of the SeaDAS (SeaWiFS Data Analysis System) algorithm applied to China coastal waters, a new atmospheric correction algorithm is discussed, developed, and used for the SSC of East China coastal waters. The advantages of the new algorithm are described through the comparison of the restdts from different algorithms.  相似文献   

福建近海主要经济渔业生物营养级和有机碳含量研究   总被引：2，自引：0，他引：2  

卢振彬  黄美珍 《台湾海峡》2004,23(2):153-158

本文研究了福建近海52种鱼类、6种虾类、4种蟹类、1种虾蛄和4种头足类的食性和营养级及其有机碳含量。结果表明：营养级以鱼类最高，为2．1～3．7级，平均2．65级；头足类为2．04～2．88级，平均2．60级；蟹类2．38～2．73级，平均2．58级；虾类最低，为1．64～2．21级，平均1．96级．干样有机碳含量百分率也以鱼类最高，为33．0％～76．2％(m／m)，平均46．25％(m／m)；头足类为27．80％～46．16％(m／m),平均40．24％(m／m)；虾类为30．60％～38．40％(m／m),平均34．90％(m/m)；蟹类最低,为25．00％～30．78％(m/m)，平均28．24％(m／m),鲜样有机碳含量百分率还是以鱼类最高,为4．80％～29．55％(m／m),平均13．75％(m／m)；蟹类为8．90％～12．68％(m／m),平均10．74％(m/m)；虾类为6．97％～11．53％(m/m)，平均9．55％(m/m)；头足类最低仅为7．38％～8．52％(m／m),平均7．95％(m/m),干样有机碳含量百分率和鲜样有机碳含量百分率与营养级均成正相关，但前者的相关性高于后者。  相似文献   

Comparison of two three-dimensional hydrodynamic modeling systems for coastal tidal motion     

Q.Y. Zhang   《Ocean Engineering》2006,33(2):137-151

A comparison of two three-dimensional numerical modeling systems for tidal elevations and velocities in the coastal waters is presented. The two modeling systems are: (1) the Princeton Ocean Model (POM) and (2) the MIKE 3 flow model. The model performance results for Singapore's coastal waters show that the predicted tidal elevations from the two hydrodynamic modeling systems are almost identical and are in very good agreement with field measurement data. The simulated tidal current velocities match well with field measurement data at the selected stations, but it seems that the POM provides the slightly better simulation, compared to the MIKE 3 flow model. The depth profiles of the velocities obtained from the two modeling systems may be greatly different at some time, due to the vertical diffusion coefficient calculated from different turbulent sub-models in the two modeling systems. The POM generally predicts larger peak tidal velocities. The maximum speed differences for the model results from the two modeling systems occur in the top and differ from time to time and from location to location, reaching up to 20%.  相似文献   

The Effect of the Introduction of the American Species Marenzelleria viridis (Polychaeta; Spionidae) on the Benthic Ecosystem of Vistula Lagoon   总被引：1，自引：0，他引：1  

Ludwik  &#;mudzi&#;ski 《Marine Ecology》1996,17(1-3):221-226

Abstract. In the late 1980s, a radical change in the macrozoobenthos composition occurred in the Vistula Lagoon, an oligohaline and silted water basin. This structural change is a result of the mass appearance of the very strongly euryhaline spionid polychaete Marenzelleria viridis Verrill, a newcomer from North American estuaries. It considerably reduced the previous bottom macrofauna, which was composed mainly of Chironornidae larvae and oligochaetes.
The penetration depth of the macrozoobenthos into the sediments and its total biomass increased in the last years, which enhanced the organic matter displacement in sediment layers of a greater thickness. The previous bottom dwellers inhabited mainly the most superficial sediment layer, whereas the new polychaete immigrant can penetrate down to a depth of 20–40 cm.  相似文献   

厄尔尼诺现象和浙江近海鲐鲹鱼渔获量变化关系──长江口ENSO渔场学问题之二   总被引：12，自引：0，他引：12  

洪华生  何发祥  杨圣云 《海洋湖沼通报》1997,(4)

本文研究浙江近海1970年到1992年鲐鱼渔获量变化与Elnino现象的关系，结合捕捞强度，长江中下游汛期（4—9月）降水量距平年际变化综合分析，探讨浙江近海鲐鱼渔获量变动规律，为合理开发渔业资源提供科学依据。  相似文献   

Primary productivity in the western tropical Pacific and equatorial warm waters   总被引：1，自引：0，他引：1  

Chen Xingqun  Zhang Ming  Chen Qihuan 《海洋学报(英文版)》2001,20(1):117-129

ＩＮＴＲＯＤＵＣＴＩＯＮＢｙｓｔｕｄｙｉｎｇｃｈｌｏｒｏｐｈｙｌｌａｎｄｐｒｉｍａｒｙｐｒｏｄｕｃｔｉｖｉｔｙｉｎｏｃｅａｎ ,ｅｉｔｈｅｒｉｎｔｈｅｂｉｇ ｓｃａｌｅｏｒｉｎｔｈｅｓｍａｌｌｓｃａｌｅ ,ｔｈｅｐｒｏｄｕｃｔｉｖｉｔｙｄｉｓｔｒｉｂｕｔｉｏｎａｎｄｖａｒｉａｔｉｏｎｏｆｍａｒｉｎｅｏｒｇａｎｉｃｍａｔｅｒｉａｌｉｎｔｈｅｔｅｍｐｏ ｒａｌａｎｄｓｐａｔｉａｌｃａｎｂｅｕｎｄｅｒｓｔｏｏｄ .Ｔｈｅｓｅａａｒｅａｓ ,ｓｉｔｕａｔｉｎｇｉｎｔｈｅｗｅｓｔｅｒｎｔｒｏｐｉｃａｌＰａｃｉｆｉｃ…  相似文献   

Springs of Great Britain     

J. B. W. Day 《Environmental Geology》1996,27(2):77-78

Predictably, in a country such as Britain, with its preponderance of consolidated, sedimentary, mainly fissure-flow aquifers, there is a very large number of springs, many of which are, or have been, used for public supply. Migratory springs are a feature of the British (Ur. Cretaceous) Chalk, the most important British aquifer. The Chalk's low specific yield and high capillary moisture retention together give rise to very considerable fluctuations (more than 33 m in some areas) of the unconfined water table. Along the gentle dip slopes of the Chalk (North and South Downs of southern and southeastern England) springs may migrate laterally for several miles, giving rise to seasonal streams locally known as bournes or lavants. However, springs such as at Duncton, West Sussex, at the base of the much steeper scarp slopes of the Chalk, form point sources, the flows from which tend to be relatively steady; such springs commonly supply and are the original reason for the existence of many of the small towns and villages which nestle along the bases of the chalk scarps of Sussex and Kent.Where the Chalk forms coastal cliffs, a number of springs break out at the base of the cliff between high and low tide levels; there are major chalk coastal springs, for instance, at St. Margaret's Bay (Kent) and at Arish Mells, east of Lulworth Cove, Dorset. Such springs are not used for direct supply (their salinity is usually too high) but are indicators of the presence of local reserves of groundwater for possible future development.  相似文献   

Trace metals in suspended particulate matter and in sediment trap material from a permanently anoxic fjord — Framvaren, South Norway     

Jens M. Skei  Douglas H. Loring  Reijo T. T. Rantala 《Aquatic Geochemistry》1996,2(2):131-147

Geochemical studies of the trace metal concentrations in suspended particulate matter (SPM) and sediment trap material from a permanently anoxic fjord, Framvaren, South Norway in 1989 and 1993 indicate that extremely high concentrations of zinc (max = 183920 mg/kg), copper (max = 4130 mg/kg), lead (max = 2752 mg/kg), and cadmium (max= 8.1 mg/kg) sometimes (1993) occur in the SPM collected in the anoxic water layer. The highest concentrations of Zn occur just below the redoxcline at 22 m water depth (in 1993), and copper, lead and cadmium have maximum concentrations between 30 and 80 m depth, where the amount of total SPM is at a minimum (about 0.3 mg/L). On a mass per volume (g/L) basis, the maximum concentrations of Cd, Cu and Fe occur at the interface (21m) and those of Zn occur just below the redoxcline (22 m depth). The SPM and sediment trap data suggest that the metals are precipitated as sulfide minerals in the anoxic water. The presence of particulate sulfides was confirmed by SEM studies that show the occurrence of discrete metal (Cu, Fe, Pb, and Zn) sulfide particles in size from 10–20 m as well as framboidal pyrites (1–5 m in size). Higher levels of metal sulfides at intermediate depths rather than in the deep water of Framvaren (> 100 m), may be due to input of trace metals by water exchange over the sill in the upper part of the water column. In the deep water, less metal sulfide precipitation takes place due to depletion of trace metals, and the dilution of particulate metal concentrations by organic matter and by the chemogenic formation of calcite.  相似文献   

江西省安福地区地热水化学特征研究     

余廷溪  刘凯  孙军亮  王路瑶  王书训 《地球学报》2024,45(1):99-111

为研究江西安福地区水文地球化学特征及控制因素, 本文采集了15组样品, 采用水化学、同位素分析等方法进行研究。结果表明: 研究区地热水以Na-HCO3型水为主, 地下水以HCO3-Na·Ca型为主, 地表水由西南向东北从HCO3-Na·Ca向HCO3-Ca型水演化。水化学组分演化过程主要受岩石风化作用控制, 地层封闭性较差, 水中的Na+、HCO– 3、Sr2+来源于硅酸岩风化溶解。由稳定同位素特征可知, 研究区地热水补给来源为大气降水。研究区热储温度为49.8~101.4 ℃, 地热水循环深度为1 502.6~1 513.6 m。热水在沿断裂带上升过程中与浅层冷水发生混合, 其混合比例为76.1%~87.5%。研究成果为安福地区水循环演化提供依据, 有利于地热资源的合理开采与保护。  相似文献   

Geochemistry of recent hydrothermal systems of Mendeleev Volcano （Kuril Islands） and surrounding waters     

Oleg Chudaev Valentina Chudaeva Kenji Sugimori Akihito Kuno Motoyuki Matsuo 《中国地球化学学报》2006,25(B08):211-211

On the Kuril Islands there are 85 volcanoes, 39 of which are active. Hot springs and mud pots are wide spread in this area and have significant inputs on the chemical composition of the surrounding surface waters and environment. We present results of trace elements as well as data on H, O, S, and He isotope ratios for hydrothermal systems of the Mendeleev Volcano （Kunashir Island） and surrounding surface waters. Water and gas samples were taken from springs and holes as well as creeks and the Lesnaya River. Among the thermal water types, three main groups can be distinguished. The first group includes the waters, in which SO4^- ion predominant. The water temperature on the surface reaches 97℃, and TDS varies from a few g/L to 7 g/L. These waters are acid to superacid with pH values ranging 0.6 to 2.3. The second group is sodium-chloride waters. A maximum TDS is 14.2 g/L. The waters are neutral or alkaline; pH varies from 6.9 to 8.2. The third group is the sodium-chloride-sulfate-bicarbonate water. The Stolbovskie springs, located in the periphery of the Mendeleev Volcano are representative of this type. The pH of these waters is close to neutral. TDS is 1.9 g/L. They are rather the derivatives of sodium-chloride waters arisen from dilution of them by subsurface waters. The Kuslyi Creek and Lesnaya River are located near the Mendeleev Volcano. The most acid springs discharge into the Kislyi Creek as a result pH of this creek being 2.5, and contents of most elements rather high. For example, the contents of dissolved solids of Si, Fe, Al, Mn, Zn, in waters of the Kislaya Creek are 22.1, 8.1, 6.2, 1.29, and 0.28 mg/L, and correspondently. The water of the Lesnaya River, （Before the Kislyi Creek, pH is about 8 with TDS 102 mg/L, but after the Kuslyi Creek, pH decreases and the concentrations of chemical elements increase. Debit of the Kislayi Creek in summer season is about 370 L/sec. It means that every day only this small creek inputs in the Lesnay River about 706 kg of Si;  相似文献