龙湖主湖区开挖及防渗方案优化研究

郑州市郑东新区龙湖这样大规模的城市人工湖建设在我国尚属首次。在平均湖深4.5 m的前提下以及已有研究成果的基础上,采用现场调研、室内外试验、水质分析及数值分析计算相结合的综合研究方法,结合实际工程经验对龙湖开挖及防渗方案进行研究,结果表明,龙湖主湖区开挖宜采用干法和湿法相结合的“综合开挖”方案;防渗宜采用水中抛土和碾压铺盖相结合的方案,这样既能保证成湖,又不会对周边地区地下水系统和地质环境造成大的影响,还能满足水质要求,从施工设备和工程投资角度来讲也是合理可行的。另外,在龙湖正式开挖之前,应先在现场进行试挖工程,对开挖、防渗设计进行优化。     

江汉平原江陵湖泊沉积物粒度特征及气候环境意义

以江汉平原江陵湖泊沉积物为研究对象,结合沉积物岩性、粒度组成、孢粉和有机碳同位素等,分析了江陵湖泊沉积物粒度组成特征及该区域近9 000 a来的气候环境变化。研究发现,江陵湖泊沉积物记录了该区湖泊水体逐渐减小直至消亡的过程,气候环境变化大致可分为以下5个阶段：（1）8 900～6 300 a B.P.为水体较深、面积较大的开阔湖阶段,气候暖湿;（2）6 300～4 700 a B.P.为面积较小、水体较浅的潴水湖阶段,气候干旱;（3）4 700～3 400 a B.P.为面积更小、水体更浅的洼地湖阶段,气候偏暖偏湿;（4）3 400～2 500 a B.P.为湖沼泥炭发育阶段,气候暖湿;（5）2 500 a B.P.以来,由湖泊及湖沼堆积转化为洪水漫滩堆积,古云梦泽开始萎缩,气候变干。江陵湖泊沉积物粒度所记录的区域气候干湿变化与国内邻近区域（特别是鄱阳-洞庭湖区）显示出较好的一致性,沉积物粒度研究是恢复区域古降水等气候环境变化的有效途径。     

中国盐湖钾盐50年回顾与展望

从中国盐湖钾盐 5 0年回顾 ,充分阐述了中国盐湖资源多、大、富、全等特点 ,及科学家们取得的科技成果。针对中国盐湖钾盐综合利用和高值化开发 ,提出了几点建议。     

东濮凹陷西洼南段老第三系岩相古地理特征

东濮凹陷西洼南段老第三系属地堑型湖盆沉积,主要发育河流相、三角洲相、冲积扇相、扇三角洲相以及湖泊相。两条边界断层,尤其是西侧长垣断层的活动性控制着该区的岩相古地理格局：断层活动强烈时,湖盆水域扩大,湖水加深,主要发育扇三角洲、三角洲及深湖－半深湖沉积;断层活动减弱时,水体变浅或干涸,湖盆被充填,主要发育冲积扇或河流相沉积。     

南极中山站及毗邻地区湖泊与冰雪CODMn研究

在 CHINARE- 1 5考察期间对中山站及毗邻地区的湖泊和冰雪进行了采样。它们的CODMn指数与中国《地面水环境质量标准》相比 ,可分为三类 :一类水质所占比重最大 ,大约为56% ,二类和三类分别为 37%、7%。各类水体的 CODMn指数主要为自然源所贡献 ,人为污染不明显。湖水的 CODMn指数是生物生长状况、有机质含量、盐度和水体氧化还原程度的综合体现 ,新鲜降雪样的 CODMn指数指示了该地区的大气洁净度。     

新疆艾比湖荒漠生态保护区建设条件评价及规划

艾比湖是新疆最大的咸水湖,地势低洼,荒漠地类多样,是一些珍稀的荒漠野生动植物的天然分布区,植物种群保存完整,在我国内陆荒漠自然生态系统中具有典型性和代表性。同时这里地处著名的阿拉山口大风通道,生态环境十分脆弱,艾比湖干缩引起的风沙灾害加剧了荒漠化进程,已危及北疆经济带社会、经济的可持续发展。尽快划定建立生态保护区,加强生态环境建设,保护生物多样性是十分紧迫的。作者着重论述了建立保护区的依据及条件,对保护区进行了区划并提出了规划意见。     

Cladoceran and chironomid assemblages as qualitative indicators of water depth in subarctic Fennoscandian lakes

The relationship between surface-sediment cladoceran and chironomid communities to lake depth was analysed in 53 lakes distributed across timberline in northern Fennoscandia using multivariate statistical approaches. The study sites are small and bathymerically simple, with water depth ranging from 0.85-27.0 m (mean 6.36 m). Maximum lake depth was the most important factor in explaining the cladoceran distributions and the second most important factor in explaining the chironomid distributions in these subarctic lakes, as assessed on the basis of a series of constrained RDAs, Monte Carlo permutation tests, and variance partitioning. Quantitative inference models for maximum lake depth were created for both groups of animals. Well-performing calibration functions for predicting lake depth were obtained in each case using linear partial least squares (PLS) regression and calibration, weighted averaging (WA) with an 'inverse' deshrinking regression, and weighted averaging partial least squares (WA-PLS). Quantitative reconstructions of lake level fluctuations should be possible from cladoceran and chironomid core data with a root mean squared error of prediction (RMSEP), as estimated by jack-knifing, of about 1.6-3.0 m.     

The magnetic properties of the recent sediments of Brothers Water, N W England

The magnetic properties of recent sediments from five short cores from Brothers Water in the English Lake District are compared with those from a set of catchment soil samples. From the comparison, it is concluded that bacterial magnetosomes have made a significant contribution to the magnetic properties of the sediments of the last five decades. This contribution is superimposed on a continuing erosive input of haematite-rich sediment from the parent materials of the catchment and may obscure any possible increase in surface soil input during recent times. The results highlight the difficulty of making sediment-source linkages where biogenic contributions to the magnetic properties of the sediment are important relative to the input of magnetic minerals from catchment erosion.     

Changes in fossil midge (Chironomidae) assemblages in response to cultural activities in a shallow, polymictic lake

Chironomid (Diptera: Chironomidae) head capsules were studied from a core of recent sediments from shallow, macrophyte-dominated Lake Opinicon, Ontario, Canada, to determine if assemblages have changed in response to lake-level changes and other watershed disturbances, including deforestation and agriculture. Our results indicate that the construction of the Rideau Canal in the early 1830s and subsequent flooding of Lake Opinicon has had the greatest impact on this system, but that even this disturbance did not greatly affect chironomid assemblages. Despite other significant cultural disturbances in the watershed, the lake sediments have recorded only minor changes in its recent history, providing support for the hypothesis of alternative lake equilibria. These results correspond well with diatom inferences of only minor changes in past lake trophic status.     

藏南沉错湖泊三角洲的沉积相及沉积环境

在西藏自治区沉错湖泊三角洲平原和湖内钻孔取芯 ,利用14 C和ESR测年方法建立了钻孔剖面的年代标尺。在岩芯描述、沉积物粒度分析和CaCO3含量分析基础上 ,对沉错湖泊三角洲的沉积环境和沉积相进行了解释分析。 36 7m长的岩芯大致记录了 5 5万年以来的沉积历史。全孔平均沉积速率约为 0 6 6 7mm/a。 16 92 0aBP以来三角洲的沉积速率较大 ,平均为 1 2 7mm/a。由于沉积物物质来源的多源性导致CaCO3在剖面上的无规律性变化。但是 ,沉积物粒度和沉积序列变化指示全套沉积由底部的冲积扇相向上过渡为水下扇亚相和三角洲沉积相。在大约 175 0 0aBP～ 14 0 0 0aBP时期 ,沉错存在高湖面阶段。沉积序列中记录了末次冰期最盛期 (LastGlacialMaximum )和新仙女木事件 (YoungerDryas)。沉积特征和沉积环境的变化主要受湖面涨缩变化所控制。而湖面升降变化的驱动因素主要为气候 ,尤其夏季风的强弱和冷事件