刘家峡水库西南部水域表层沉积物重金属污染评价

为了研究刘家峡水库西南部水域表层沉积物中重金属的污染状况,对采集的55个表层沉积物样品中的6种重金属元素Cr、Cd、Ni、Cu、Zn和Pb的含量进行测试,其平均含量分别为77.03μg/g、0.16μg/g、33.53μg/g、32.09μg/g、291.77μg/g、22.44μg/g。在研究表层沉积物重金属含量空间分布的基础上,运用单因子污染指数法、内梅罗综合污染指数法、地累积指数法、潜在生态风险指数法,综合判断水库的受污染程度并对其潜在生态风险进行评估。6种元素的地累积指数排序依次为：Zn > Cu > Cd > Ni > Pb > Cr;潜在生态风险系数排序依次为：Cd > Cu > Pb > Zn > Ni > Cr;各区域重金属污染程度或潜在生态风险水平依次为黄河主河道 > 大夏河河口 > 黄河横剖面。综合4种方法的评价结果,认为对刘家峡水库西南部表层沉积物重金属污染及潜在生态风险评价贡献率较高的重金属污染因子是Zn、Cu和Cd;综合相关性分析与主成分分析,认为研究区沉积物重金属污染主要来源于两个方面：（1） Zn、Cu主要来源于生活污染或工业污染;（2） Cd主要来源于工农业活动产生的污染。     

Reservoir rehabilitation: The new methodological approach of Economic Environmental Defence

This paper proposes a new methodological approach to silted reservoir management and defence, which combines the reservoir rehabilitation process and the utilization of the recovered water volumes and sediments. This approach, strategic from both the economical and environmental points of view, is here defined as Economic Environmental Defence (EED) of a reservoir. The EED approach is applied to the case study of Guardialfiera reservoir, where the available experimental data allowed the estimation of silta-tion up to date, the analysis of the distribution of sediment particle size along the reservoir bottom and the possibility to propose a feasible utilization of water and sediments resulting from the reservoir rehabilitation.     

三峡库区山地灾害基本特征及滑坡与降水关系

连阴雨是滑坡、崩塌等地质灾害的重要诱发因素,也是三峡水库安全的潜在威胁。利用三峡库区39个站1960—2015年春季逐日降水观测资料,分别分析了总的连阴雨和各类连阴雨的时空分布特征和变化趋势。结果表明：（1）从空间上看,连阴雨过程频次、总天数和总降水量均呈现自北向南逐渐增多的分布特征;从时间上看,在近56 a连阴雨过程的频次、总天数和总降水量呈明显减少趋势,1979年以来过程降水强度显著增强且年际变率明显。（2）从分类来看,持续时间5~6 d的短期过程频次、总天数以及总降水量均呈弱增加趋势,降水强度在整个库区均较强,持续时间7~10 d的中期过程和持续时间10 d以上的长期过程频次、总天数和总降水量呈减少趋势,且长期过程的减少趋势更明显,在2000年以后很少出现。（3）从连阴雨过程总降水量对春季总降水量的贡献占比趋势来看,连阴雨的贡献减弱,而小于5 d的非连阴雨过程增多。（4）就不同类型连阴雨而言,库区以南的区域主要以长期过程为主,而以北的地区主要以短、中期过程为主。（5）连阴雨过程总降水量的变化主要由过程总天数的变化引起。值得关注的是,在连阴雨长时间减少的背景下,在最近10 a来却表现出一些新的特征,连阴雨过程发生频次、总天数和总降水量增多且年际变率增大,特别在三峡库区的东南部,应重点关注库区东南部地质灾害。

     

Experimental study on the effect of bottomless structure in front of a bottom outlet on a sediment flushing cone

One of the main problems in reservoirs is sedimentation which reduces the operating life of dams if a proper plan and analysis method are not in place.The techniques to manage sediment in reservoirs include several sustainable management techniques that route sediment through or around the reservoir.One of the main economical methods in arid and semi-arid regions is pressurized flushing using moderate drawdown of the water level of the reservoir to evacuate sediment deposited behind dams.In the current study,the effect of a new structure called a dendritic bottomless extended(DBE)outlet structure at three angles of 30°,45°,and 60°
on pressurized flushing efficiency was investigated.Consequently,45 experiments were designed for three discharge rates (Qo),three sediment levels(Hs),four types of structure,and a no-structure condition(reference test).The results indicated that the DBE structure with a 30°angle between the branches,a sedimentary dimensionless index of Hs/Do=4.59,and a flow dimensionless index of Qo=/√gD05=1:43(where g is the acceleration of gravity and Do is the diameter of the bottom outlet)lead to 10-fold increase in the sediment flushing cone dimensions and sediment removal efficiency compared to the results of the reference test.Finally,according to a statistical analysis of the results,a dimensionless equation for calculating the sediment flushing cone dimensions was developed for the tested sediment characteristics.     

Integrated Interpretation of Interwell Connectivity Using Injection and Production Fluctuations

A method to characterize reservoirs, based on matching temporal fluctuations in injection and production rates, has recently been developed. The method produces two coefficients for each injector–producer pair; one parameter, λ, quantifies the connectivity and the other, τ, quantifies the fluid storage in the vicinity of the pair. Previous analyses used λ and τ separately to infer the presence of transmissibility barriers and conduits in the reservoir, but several common conditions could not be easily distinguished. This paper describes how λ and τ can be jointly interpreted to enhance inference about preferential transmissibility trends and barriers. Two different combinations are useful: one is a plot of log (λ) versus log (τ) for a producer and nearby injectors, and the second is a Lorenz-style flow capacity (F) versus storativity (C) plot. These techniques were tested against the results of a numerical simulator and applied to data from the North Buck Draw field. Using the simulated data, we find that the F–C plots and the λ–τ plots are capable of identifying whether the connectivity of an injector–producer well pair is through fractures, a high-permeability layer, multiple-layers or through partially completed wells. Analysis of data from the North Buck Draw field shows a reasonable correspondence between τ and the tracer breakthrough times. Of two possible geological models for Buck Draw, the F–C and λ–τ plots support the model that has less connectivity in the field. The wells in fluvial deposits show better communication than those wells in more estuarine-dominated regions.     

于桥水库流域农业非点源磷污染控制区划研究

以于桥水库流域28个次级小流域作为区划对象,以影响该区域农业非点源磷污染的6个主要因子,包括降雨侵蚀力因子(R),土壤可蚀性因子(K),地形因子(LS),植被覆盖因子(C)以及土壤有效磷含量(SAP)和化肥磷施用量(FP),作为区划因子,采用系统聚类法进行区划,将于桥水库流域分为4类磷污染控制类型区,分析了各个类型区的生态环境特征、农业非点源磷污染特征和主要影响因子,提出相应的控制措施。为进一步进行更深入的研究提供科学依据。     

大桥水库MS4.6级诱发地震的初步研究

2002年3月3日大桥水库诱发了Ms4．6级水库地震，其发震构造是安宁河东支断裂近傍具有正断层性质的一个分支断裂。据大桥台网7年多库区地震观测事件记录，地震空间分布上水体附近有一个明显的活跃过程，大坝上游发生小震群，大坝下游发生主震序列。地震的震源深度在蓄水前后有明显变化。4．6级地震的震源机制解的主压应力轴方位和倾角与大多数活动断裂上的地震有明显的差别，主压应力轴的倾角与其它的水库地震相比也存在较大差别。     

水库设计的三维可视化研究

为了提高水库设计的自动化水平,实现模型的三维可视化,本文研究了三维地形的建模方法及其在水库设计中的应用。采用了地性特征点和地性线参与三维建模的方法,提高了数字高程模型DEM的地形逼真度。在此基础上通过一种综合了水平线和覆盖消隐算法的合成消隐算法实现了彻底的消隐以及图像的快速生成。通过三维水库模型,不仅可以得到水库的容量、库水的淹没边界和淹没面积,而且还可以生成地形剖面图。如果地形剖面图与地质图、水文图、构造图等进行叠加,可以形成综合剖面图。文章最后采用三维可视化方法模拟了某水库的部分设计工作,结果表明,通过水库的三维地形模型可以简单直观的完成坝址的选择、水库容量以及蓄水的水位线的确定等方面的工作。     

准噶尔盆地玛湖凹陷风城组页岩油储层岩相划分与类型评价

准噶尔盆地玛湖凹陷风城组页岩油藏是继吉木萨尔凹陷芦草沟组页岩油藏之后的又一重大发现,风城组沉积期玛湖凹陷具有近陆源供给、火山活动频发、气候干旱炎热的特点,为独具特色的盐碱化湖泊沉积环境创造了条件,也是风城组岩性复杂多变的重要原因。火山岩、内源岩、陆源碎屑岩以及多源混积岩纵向频繁叠置,形成米级到厘米级页岩油储层。结合岩性变化特征,以构造样式作为突破口,厘米级尺度岩心观察为基础,高频沉积构造分析为辅助,利用亚离子抛光电镜、能谱测试、荧光分析等多种技术手段对准噶尔盆地玛湖凹陷风城组页岩油储层进行岩性岩相分析,认为玛湖凹陷风城组页岩油储层可划分为4大类（砂砾岩类、火山岩类、混积岩类与内源岩类）、8小类储层。4大类储层储集性能逐渐减弱,其中混积岩类储层因其构造与成分差异可进一步划分为混积页岩、纹层–似纹层状混积泥岩、树根状–网状混积泥岩、雪花–星点状混积泥岩;页理发育情况、云质含量以及其产出样式成为混积岩类储层储集物性差异的重要控制因素。     

诱发因素影响下的滑坡参数优化预测模型研究

本文结合三峡库区地质灾害监测预警建设历程、地质灾害监测分析现状及面临的问题,从地质灾害监测分析概念和内涵、发展趋势等方面进行了探讨,获得了以下认识：(1)探讨了地质灾害监测分析的内涵,提出了地质灾害监测分析的定义,即围绕着监测目的、监测内容和监测方法,对地质灾害监测数据及相关成果资料开展综合性分析的工作,针对预警预报、防控决策、施工安全、工程效果等不同监测目的,总结了地质灾害监测分析的主要内容;(2)面对多源、异构、实时、海量的地质灾害监测及相关数据,发展地质灾害智能化监测分析系统,实现地质灾害监测数据、分析技术方法、应用服务以及监测分析工作流程化等方面有效集成,是破解监测分析困境和问题的关键。