Study on Water Resources Regulation and Reservoir Operating Prediction for Suppression of Salt Water Intrusion in the Pearl River Estuary

Salt water intrusion occurred frequently during dry season in Modaomen waterway of the Pearl River Estuary. With the development of region's economy and urbanization, the salt tides affect the region's water supply more and more seriously in recent years. Regulation and allocation of freshwater resources of the upper rivers of the estuary to suppress the salt tides is becoming important measures for ensuring the water supply security of the region in dry season. The observation data analysis showed that the flow value at the Wuzhou hydrometric station on the upper Xijiang river had a good correlation with the salinity in Modaomen estuary. Thus the flow rate of Wuzhou has been used as a control variable for suppression of salt tides in Modaomen estuary. However, the runoff at Wuzhou mainly comes from the discharge of Longtan reservoir on the upper reaches of Xijiang river and the runoff in the interval open valley between Longtan and Wuzhou sections. As the long distance and many tributaries as well as the large non-controlled watershed between this two sections, the reservoir water scheduling has a need for reasonable considering of interaction between the reservoir regulating discharge and the runoff process of the interval open watershed while the deployment of suppression flow at Wuzhou requires longer lasting time and high precision for the salt tide cycles. For this purpose, this study established a runoff model for Longtan - Wuzhou interval drainage area and by model calculations and observation data analysis, helped to understand the response patterns of the flow rate at Wuzhou to the water discharge of Longtan under the interval water basin runoff participating conditions. On this basis, further discussions were taken on prediction methods of Longtan reservoir discharge scheduling scheme for saline intrusion suppression and provided scientific and typical implementation programs for effective suppression flow process at the Wuzhou section.

Spatial variability in water quality and surface sediment diatom assemblages in a complex lake basin,lake of the woods,ontario,canada

Lake of the Woods (LOW) is an international waterbody spanning the Canadian provinces of Ontario and Manitoba, and the U.S. state of Minnesota. In recent years, there has been a perception that water quality has deteriorated in northern regions of the lake, with all increase in the frequency and intensity of toxin-producing cyanobacterial blooms. However, given the lack of long-term data these trends are difficult to verify. As a first step, we examine spatial and seasonal patterns in water quality in this highly complex lake on the Canadian Shield. Further, we examine surface sediment diatom assemblages across multiple sites to determine if they track within-take differences in environmental conditions. Our results show that there are significant spatial patterns in water quality in LOW. Principal Component Analysis divides the lake into three geographic zones based primarily on algal nutrients (i.e., total phosphorus, TP), with the highest concentrations at sites proximal to Rainy River. This variation is closely tracked by sedimentary diatom assemblages, with [TP] explaining 43% of the variation in diatom assemblages across sites. The close correlation between water quality and the surface sediment diatom record indicate that paleoecological models could be used to provide data on the relative importance of natural and anthropogenic sources of nutrients to the lake.

Model analysis of dissolved inorganic phosphorus exports from the Yangtze river to the estuary

In this paper, we estimate the inputs of phosphorus (P) to the Yangtze River Basin and exports of dissolved inorganic phosphorus (DIP) from the river to the estuary for the period 1970-2003, by using the global NEWS-DIP model. Modeled DIP yields range from 2.5 kg P km(-2) yr(-1) in 1970 to 4.6 kg P km(-2) yr(-1) in 1985, and then dramatically increase to 14.1 kg P km(-2) yr(-1) in 2003. No significant difference between the modeled and measured values at the level of P = 0.05 is observed. The study also demonstrates variable source contributions of P to the modeled DIP during the period 1970-2003. Point sewage P input accounted for approximately 100% in the period 1970-1985 and substantially decreased to 24.8% in 2003. Chemical fertilizer contributed 25.4% of DIP yields in 1986 and increased continuously to 50.3% in 2003, while a stable trend in manure P contribution averaging 22.9% of DIP yields was shown in the same period. The study concludes that P inputs to the Yangtze River Basin and the river DIP export to the estuary have substantially increased during the study period consequence to human pressure.

Fine-grained Pleistocene deepwater turbidite channel system on the slope of Qiongdongnan Basin, northern South China Sea

Recently, as oil exploitation has become focused on deepwater slope areas. more multi-channel high resolution 2D and 3D seismic data were acquired in the deepwater part of the Qiongdongnan Basin, northern South China Sea. Based on 3D seismic data and coherence time slice, RMS and 3D visualization, a series of deepwater channels were recognized on the slope that probably developed in the late Quaternary period. These channels trend SW-NE to W-E and show bifurcations, levees, meander loops and avulsions. High Amplitude Reflections (HARs), typical for channel-levee complexes, are of only minor importance and were observed in one of the channel systems. Most of the detected channels are characterized by low-amplitude reflections, and so are different from the typical coarse-grained turbidite channels that had been discovered worldwide. The absence of well data in the study area made it difficult to determine the age and lithology of these channels. Using a neighboring drill hole and published data about such depositional systems worldwide, the lithology of these channels is likely to be dominated by mudstones with interbedded thin sandstones. These channels are formed by turbidity currents originated from the little scale mountain river of mid-Vietnam in SW direction and were probably accompanied by a relative sea level drop in the last glacial age. These channels discovered on the northern South China Sea slope are likely to be fine-grained, mud-dominant and low N:G deposits in a deepwater paleogeographic setting. (C) 2009 Elsevier Ltd. All rights reserved.

Summertime ciliate and copepod nauplii distributions and micro-zooplankton herbivorous activity in the Laizhou Bay, Bohai Sea, China

The abundance and biomass of ciliated protozoa and copepod nauplii were investigated at 21 grid stations and two anchored stations in the Laizhou Bay, Bohai Sea, China in June 1998. Dilution incubations were carried out to investigate micro-zooplankton grazing pressure at the anchored stations during spring tide and neap tide. The dominant species were Tintinnopsis amoyensis, T. chinglanensis, T. pallida and aloricate ciliates. A total of 13 species of tintinnids were found. The total abundance of ciliates and nauplii ranged from 30 to 2390 ind l(-1) at grid stations. Tintinnopsis amoyensis was the only ciliate found at the anchored stations and in concentrations which varied from 0 to 6700 ind l(-1). The spatial distribution of ciliates was patchy. Tintinnopsis amoyensis and T. pallida were distributed in the Weihe River mouth and Xiaoqinghe River mouth respectively. The aloricate ciliates, T. chinglanensis and Codonellopsis ostenfeldi dominated offshore in sequence. The water mixing process may affect the spatial pattern of the dominant ciliate species. The abundance and biomass of copepod nauplii were in the range of 0-140 ind l(-1) and 0-7 mu g C l(-1) respectively, with the peak appearing at grid station 15. The total biomass of ciliates and copepod nauplii was in the range of 1(.)5-25 mu g C l(-1). Water column biomass of ciliates and nauplii varied from 2(.)37 to 52(.)3 mg C m(-2). At the anchored stations, the phytoplankton growth rates ranged from undetectable to 0 21 d(-1) and micro-zooplankton grazing rates from 0 13 to 0(.)57 d(-1). The grazing pressure of micro-zooplankton were 12 to 43% of the chlorophyll standing stock and 84 to 267% of the chlorophyll (C) 2000 Academic Press.

冀东油田柳南地区新近系油藏剩余油形成及分布规律研究

This thesis is based on the research project of Study on the Geological Characteristics and Remaining Oil Distribution Law of Neogene Reservoirs in Liunan Area, which is one of the key research projects set by PetroChina Jidong Oilfield Company in 2006. The determination of remaining oil distribution and its saturation changes are the most important research contents for the development and production modification of oilfields in high water-cut phases. Liunan oilfield, located in Tangshan of Hebei Province geographically and in Gaoliu structural belt of Nanpu sag in Bohai Bay Basin structurally, is one of the earliest fields put into production of Jidong oilfield. Focusing on the development problems encountered during the production of the field, this thesis establishes the fine geological reservoir model through the study of reservoir properties such as fine beds correlation, sedimentary facies, micro structures, micro reservoir architecture, flow units and fluid properties. Using routine method of reservoir engineering and technology of reservoir numerical modeling, remaining oil distribution in the target beds of Liunan area is predicted successfully, while the controling factors of remaining oil distribution are illustrated, and the model of remaining oil distribution for fault-block structure reservoirs is established. Using staged-subdivision reservoir correlation and FZI study, the Strata in Liunan Area is subdivided step by step; oil sand body data-list is recompiled; diagram databases are established; plane and section configuration of monolayer sandstone body, and combination pattern of sandstone bodys are summarized. The study of multi-level staged subdivision for sedimentary micro-facies shows that the Lower member of Minghuazhen formation and the whole Guantao formation in Liunan Area belong to meandering river and braided river sedimentary facies respectively, including 8 micro facies such as after point bar, channel bar, channel, natural levee, crevasse splay, abandoned channel, flood plain and flood basin. Fine 3D geological modeling is performed through the application of advanced software and integration of geological, seismic logging and reservoir engineering data. High resolution numerical simulation is performed with a reserve fitting error less than 3%, an average pressure fitting fluctuation range lower than 2Mpa and an accumulate water cut fitting error less than 5%. In this way, the distribution law of the target reservoir in the study area is basically recognized. Eight major remaining oil distribution models are established after analysis of production status and production features in different blocks and different layers. In addition, fuzzy mathematics method is used to the integreted evaluation and prediction of abundant remaining oil accumulation area in major production beds and key sedimentary time units of the shallow strata in Liunan Area and corresponding modification comments are put forward. In summary, the establishment of fine reservoir geological model, reservoir numerical simulation and distribution prediction of remaining oil make a sound foundation for further stimulation of oilfield development performance.

柴西南区下干柴沟组下段层序地层格架内沉积相展布及有利储集砂体分布研究

Lower member of the lower Ganchaigou Formation in the southwestern of Qaidam Basin is one of the main targeted exploration zones. With the advancement of exploration, the targets are gradually switching into the lithologic reservoirs and it is urgent to gain the more precise research results in distribution of sedimentary facies and sandstones. Guided by the theory of sequence stratigraphy and sedimentology as well as on the basis of many logging data, drillings, seismic data and chemical tests, the paper comprehensively analyzes the sedimentary facies and sandstones in the lower member of lower Ganchaigou Formation in the southern of Chaixi. According to the identification marks of the key interface in sequence stratigraphy, the key interfaces in lower member of lower Ganchaigou Formation in the southwestern of Qaidam Basin are identified as two third-order sequences SQ1、SQ2. By calibrating the synthetic seismogram, the seismic sequence, well drilling and logging sequences are united. Based on the works above, this paper chooses seven primary cross-sections and builds connecting-well stratigraphic correlation of seven main connecting-well sections. Ultimately, the high-resolution sequence stratigraphic frameworks in the lower member of the lower Ganchaigou Formation, which are uniform to logging and seismic data, are figured out. In terms of study on each sequence features, the main style of the base-level cycle overlay which forms the third-order sequence is confirmed. It contains asymmetric “becoming deep upward” style and symmetry style. Researching on the spreading characters of sequence stratigraphy indicates that SQ1 and SQ2 are rather thicker near northwest well Shashen 20 and Shaxin1 while they are quite thiner near Hongcan 1, Yuejin, Qie 4 and Dong8-Wu3, and the thickness of SQ1 is thicker than SQ2.Based on the deep analysis of the marks for depositional facies, it is proposed that the lake facies and braid river deltas facies mainly occurred in study areas. Besides, the sorts of sub-facies and micro-facies model are divided and described. Under the control of high-resolution sequence stratigraphic framework, three source directions from Arlarer Mountain、Qimantage Mountain and Dongchai Mountain are identified by using the features of heavy mineral assemblage and paleogeomorphy. In addition, regularities of distribution sedimentary facies in sequence stratigraphic framework are studied in accordance with research thinking of the "point" (single well) "line" (section) "face" (plane). In the stage of lower member in the lower Ganchaigou Formation in the southwestern of Qaidam Basin, it is at the early phrase of evolution of the lake basin with the gradual outspread and the rise of the lake level. Combined with physical analysis of reservoir sands formed in different sedimentary environment, the paper studies the style of favorable sandstone bodies that are underwater distributary channel of braided rive delta front, coarse sand in mouth bar and the sand body in sand flat of shore-shallow lacustrine facies. Finally, this article comprehensively analyzes the distribution relationship between sedimentary facies and favorable sandstone body and proposes the ideas that sequence SQ1 Yuejin area, well east 8-wu3 area, well qie4-qie1 area and well hongcan2 area are distributed areas of favorable sandstone.

A Quantitative Study on Paleo—River Environment During Late Jurassic on yaojie Region,Minhe Basin

Fluvial Sedimentation of alluvial facies prevailed during the Late Jrassic in the Minhe Basin.On the basis of the study of sedimentary facies of the Upper Jurassic series.this paper focuses on the river types suing the "Architecture Element" analysis method proposed by Miall,and calculated all the quantitative parameters to reflect the characteristics of the stream channel geometry and hydrodynamic conditions of paleo-rivers with the equations of ethrideg,schumm et al.Finally,we discussed the characteristics of environmental evolution of palsorivers on the quantitative basis.Our conclusion indicates that the evolution of paleo-rivers during the Late Jurassic,from early to late,shows such a tendency as alluvial fan river→ braid river→alluvial fan river→mid-sinuoisty river→ high-sinuosity river.

乌江流域不同演化阶段水库汞的输入输出通量研究

北欧和北美的研究发现水库是典型的汞敏感生态系统，新建水库而引起的鱼体甲基汞污染问题已受到科学家的高度重视，而我国在这方面的研究比较薄弱。本论文选择乌江流域的6个水库作为研究对象，并根据年龄把这些水库划分为3个演化阶段，洪家渡、引子渡、索风营水库为初级演化阶段，普定、东风水库为中级演化阶段，乌江渡水库为高级演化阶段。对这6个水库总汞和甲基汞的输入和输出通量进行了研究，探讨了不同演化阶段的水库对总汞和甲基汞的“源/汇”作用，主要研究内容有以下三个方面：(1)各水库入出库河流中汞的分布特征；(2)大气降水中汞浓度及沉降通量的分布；(3)乌江流域不同水库汞的输入输出通量。通过本论文的研究，得出以下主要结论： 1. 乌江流域河流中总汞、颗粒态汞、溶解态汞、活性汞、总甲基汞、溶解态甲基汞的年均浓度分别为3.41±1.98、2.05±1.73、1.36±0.44、0.24±0.11、0.15±0.06、0.08±0.03 ng•L-1。与国内外其它河流的比较发现，总汞的浓度明显低于国外受污染的河流，略高于国外未受污染的河流。溶解态汞、活性汞、甲基汞的浓度略低于受污染的河流，与未受污染的河流基本相当。与同处在贵州喀斯特地区的阿哈湖、红枫湖、百花湖的入出库河流相比，总汞、溶解态汞、活性汞、甲基汞、溶解态甲基汞的浓度均明显偏低。 2. 水库的修建显著降低了出库河流中总汞、颗粒态汞的浓度，使总甲基汞和溶解态甲基汞的浓度升高，而且增加了出库河流中溶解态汞、活性汞、总甲基汞占总汞的比例。不同形态汞的沿程分布显示，梯级水库的修建改变了河流原有的汞的生物地球化学过程，使乌江多个河段的甲基汞升高，并且随着水库生态系统的不断演化，水库输出的甲基汞将增加，下游河流水体中甲基汞有继续升高的趋势。 3. 大气降雨中总汞、溶解态汞、颗粒态汞、活性汞、总甲基汞的浓度分别为7.49~149 ng•L-1、1.23~10.0 ng•L-1、5.76~142 ng•L-1、0.56~2.94 ng•L-1、0.08~0.82 ng•L-1，且以颗粒态汞为主，约占总汞比例的87%。总汞、溶解态汞、颗粒态汞、甲基汞的浓度有明显的季节变化趋势，冬春季高于夏秋季，而空间分布特征不明显。2006年总汞、甲基汞的年湿沉降通量为34.7±5.80 µg•m-2•yr-1、0.18±0.03 µg•m-2•yr-1，且主要受降雨量的影响。乌江流域降雨中总汞的浓度及其湿沉降通量远高于北美和日本，低于中国的一些城市地区（如长春和北京），而甲基汞的浓度和通量与其它地区相当。 4. 在乌江流域的不同水库中，降雨输入总汞和甲基汞的通量主要受降雨量和水库面积的影响，而与降雨的汞浓度间没有相关性。河流向水库输入总汞的量主要受河流流量的控制，而输入甲基汞和颗粒物的量受河流流量和浓度的影响。下泄水输出总汞、甲基汞、颗粒物的通量受浓度和流量的影响。由于流域面积/水面面积的比值较大，水库水量、总汞、甲基汞、颗粒物的输入以河流为主，分别占总输入的87%、80%、85%、86%。输出以下泄输出为主，下泄水输出的水量、总汞、甲基汞、颗粒物分别占总输出的80%、77%、86%、79%。 5. 从输入-输出通量的结果发现，各水库均表现为河流颗粒物输送的“汇”；除乌江渡水库外，其它水库均表现为总汞的“汇”；对甲基汞而言，引子渡、洪家渡、索风营水库表现为“汇”，而普定、东风、乌江渡水库则表现为“源”。 6. 普定和洪家渡水库中总汞的贮存率为56%和57%，明显高于其它水库，说明在上游有水库存在的情况下，水库对总汞“汇”的作用将降低。普定、东风、乌江渡水库中甲基汞的净通量分别为+69.4 g•yr-1、+368 g•yr-1、+857 g•yr-1，转化率为13%、73%、84%，说明甲基汞的净通量和转化率与水库的演化阶段有关，随着水库演化阶段的升高而增加，并且随着水库的不断演化，甲基汞将从“汇”变成“源”。