南黄海海相中—古生界储集条件分析与预测

南黄海位于下扬子地块的东部,是我国海相中、古生界发育最齐全,现今保存相对较完整的地区之一。在对该区构造背景、构造演化、地层发育特征等分析的基础上,充分利用现有的钻井、测井、地震等资料,初步分析、预测了该区海相中古生界的储集条件。综合分析南黄海地区的地层展布、沉积、断裂发育等特征,结合邻区资料的对比,初步预测了研究区有利的储集区带。     

金沙江水网及其地震地下水前兆监测能力的讨论

A groundwater observational network for monitoring seismic precursors has been established at the reservoirs on the lower reaches of the Jinsha River in southwestern China, where a series of hydropower stations are under construction. It is the second network in China that is operated by enterprises with the purpose to observe and study earthquake precursors in reservoir areas. This paper presents the layout and technical constitution of the network, features of its observational wells and aquifers and the preliminary result of its experimental operation. Its capability to monitor seismic precursor is evaluated based on an analysis of the well-aquifer system as well as the multiple-monthly, monthly, daily and hourly variations of water levels and water temperatures observed by this network.     

Hydropower – A Green Energy? Tropical Reservoirs and Greenhouse Gas Emissions

Reservoirs are man‐made lakes that severely impact on river ecosystems, and in addition, the new lake ecosystem can be damaged by several processes. Thus, the benefits of a reservoir, including energy production and flood control, must be measured against their impact on nature. New investigations point out that shallow and tropical reservoirs have high emission rates of the greenhouse gases CO₂ and CH₄. The methane emissions contribute strongly to climate change because CH₄ has a 25 times higher global warming potential than CO₂. The pathways for its production include ebullition, diffuse emission via the water‐air interface, and degassing in turbines and downstream of the reservoir in the spillway and the initial river stretch. Greenhouse gas emissions are promoted by a eutrophic state of the reservoir, and, with higher trophic levels, anaerobic conditions occur with the emission of CH₄. This means that a qualitative and quantitative jump in greenhouse gas emissions takes place. Available data from Petit Saut, French Guinea, provides a first quantification of these pathways. A simple evaluation of the global warming potential of a reservoir can be undertaken using the energy density, the ratio of the reservoir surface and the hydropower capacity; this parameter is mainly determined by the reservoir's morphometry but not by the hydropower capacity. Energy densities of some reservoirs are given and it is clearly seen that some reservoirs have a global warming potential higher than that of coal use for energy production.     

福建省水库底栖动物及渔业利用前景

１９８９年４月至１９９０年１月对福建省３３座不同类型水库底林动物的调查,获各类底栖动物８科３０属４９种,并对底栖动物的种类组成、密度,生物量分布特点及水库水关系进行了初步揭示,根据底栖动物的种群密度和生物量,对调查水库进行了营养分类,提出了合理的渔业利用建议。     

Development of a diatom-based model for inferring total phosphorus in southeastern Australian water storages

Diatom-based transfer functions for inferring epilimnetic total phosphorus (TP) have been developed from a data set of 33 southeastern Australian water storages. Regular institutional monitoring of these sites has allowed comparison of models developed from TP data covering different time periods. A model based on mean annual TP performs better than models derived from winter maximum TP, spring minimum TP or TP nearest the time of diatom sampling. A mean annual TP model (WA-PLS 2 component) has a jack-knifed diatom-inferred versus measured TP correlation coefficient (r ² _jack) of 0.69 and a root-mean-square-error of prediction (RMSEP) of 0.246 log₁₀g TP l^–1, while alternative models have RMSEP > 0.27. Deletion of two samples with uncharacteristic species composition and environmental conditions improved performance of the mean annual TP model (r ² _jack= 0.74; RMSEP = 0.233 log₁₀g TP l^–1). Comparison with other published diatom-TP calibration models indicates that this model performs relatively well, with possible contributing factors including the extensive characterisation of TP (with an average 15 determinations making up the annual mean) and the dominance of planktonic diatoms in most sites. Downcore application of the model will allow the reconstruction of reservoir nutrient histories since commissioning, and thus provide a basis for understanding and management of reservoirs.     

羌塘盆地侏罗系低渗透碎屑岩储集层特征

羌塘盆地侏罗系碎屑岩主要包括三角洲相、滨海相和河流相砂体,岩性以细砂岩和粉砂岩为主。储层经历了较强的压实作用和胶结作用,颗粒间线—凹凸接触,胶结物主要为钙质和硅质,储集空间以次生溶孔为主,包括颗粒溶孔、粒间溶孔等,溶孔以中孔和小孔为主,喉道为细喉和微喉,构造裂缝的发育对改善储层的渗透性有重要作用。物性统计表明:孔隙度大多小于5%,渗透率小于1mD,为低孔、低渗储层。结合低渗储层分类标准,将碎屑岩储集层分为3类进行了评价,认为上侏罗统雪山组储层最好,其次为中侏罗统雀莫错组,而夏里组相对较差;最有利储集层发育区主要位于北羌塘坳陷西部中央隆起带北缘和盆地东部雀莫错地区,较有利储层发育区位于北羌塘坳陷中部和东部地区,南羌塘坳陷储集层较差。压实作用和胶结作用较强,后期溶蚀作用相对较弱,是造成目前低孔低渗储层的主要因素。     

长江河口咸潮入侵规律及淡水资源利用

长江河口系多级分汉潮汐河口,其盐水入侵有外海入侵、倒灌、浅滩通道水体交换及漫归槽等４种形式,时间上有周日、朔望、洪枯季、年际等变化特点,南支－南港河希纵向上存在３条盐度梯度急剧春特有的盐度时空变化规律。研究成果对宝钢水源长江引水方案的形成超了重要作用,并为陈行水库的选址、库容设计提供了基础数据。在长江河口建库,研究工作的重点是推算最长连续取不到合格水的天数,它是确定库容的关键数据。     

埋藏方式控制储层压实效应的定量表征——以库车坳陷白垩系砂岩储层为例

埋藏方式对于储层压实作用的制约效应非常明显,但其定性描述无法精确反映其所涵盖的诸多因素。由此引入时—深指数(TDI指数),是对储层埋藏历史中时间、温度和埋藏压力三者的综合表征,并以定量形式揭示埋藏方式的差异。以库车坳陷白垩系砂岩储层为例,探讨TDI指数对于储层粒间体积的制约效应,两者呈现明显的相关性,表明TDI指数不仅可以较好地表征储层埋藏方式的差异,也对于储层储集物性有着特殊的预测效果。     

Hydroclimatic influence of large‐scale circulation on the variability of reservoir inflow

In this study, the nature of basin‐scale hydroclimatic association for Indian subcontinent is investigated. It is found that, the large‐scale circulation information from Indian Ocean is also equally important in addition to the El Niño‐Southern Oscillation (ENSO), owing to the geographical location of Indian subcontinent. The hydroclimatic association of the variation of monsoon inflow into the Hirakud reservoir in India is investigated using ENSO and EQUatorial INdian Ocean Oscillation (EQUINOO, the atmospheric part of Indian Ocean Dipole mode) as the large‐scale circulation information from tropical Pacific Ocean and Indian Ocean regions respectively. Individual associations of ENSO & EQUINOO indices with inflow into Hirakud reservoir are also assessed and found to be weak. However, the association of inflows into Hirakud reservoir with the composite index (CI) of ENSO and EQUINOO is quite strong. Thus, the large‐scale circulation information from Indian Ocean is also important apart form the ENSO. The potential of the combined information of ENSO and EQUINOO for predicting the inflows during monsoon is also investigated with promising results. The results of this study will be helpful to water resources managers due to fact that the nature of monsoon inflow is becoming available as an early prediction. Copyright © 2009 John Wiley & Sons, Ltd.     

Temporal Change of Runoff and Sediment Load and their Differential Response to Human Activities：A Case Study for a Well-vegetated Mountain Watershed of Southern China

This study examined the temporal trends of runoff and sediment load and their differential response to human activities in the Lishui river,a tributary of the Yangtze river in southern China.The long-term observation data at four gauging stations,generally involving two periods from 1954 to 1985 and from 2007 to 2011,were used.We detected no significant temporal trend for both the annual runoff volume（Q） and the annual suspended Sediment Load（SL） over more than 30 years before 1985.The flow duration curves and the Suspended Sediment Concentration（SSC） also hold constant before 1985.Compared with the period before 1985,SL has decreased by about 80% though Q remains unchanged for the period after 2007.Detailed examination shows that the flow duration curves after 2007 have changed with a significant decrease in the high-flow component,which acts as a major cause for the decreasing SL.In addition,SSC has decreased by several times,which also contributes to the decrease in SL after 2007.Both decreases in high-flow discharges and in SSC can be linked with recent human activities,mainly including vegetation establishment and dam constructions.The constant Q and the decreasing SL are also reported for the main stream of the Yangtze River and other major rivers in southern China,although they are orders of magnitude larger than our study area in drainage area size.The present study highlights the importance of high-flow discharges on SL and suggests that the use of SL is more appropriate to reflect environmental change than Q.