崖19-1-1井晚第三纪浮游有孔虫深度分层及其古海洋学意义

依据ＧｅｒｔａＫｅｌｅｒ和Ｇａｓｐｅｒｉ，Ｋｅｎｎｅｔｔ有关中新世印度洋和太平洋浅层水、中层水和深层水浮游有孔虫深度分层组合的划分模式，对南海琼东南盆地崖１９－１－１井晚第三纪浮游有孔虫作了定量研究，并分析了陆架海区浮游有孔虫不同深度分层组合含量的变化与古地理环境变迁的关系。崖１９－１－１井以浅层水、中层水组合为主，深层水组合不发育，反映本区温跃层不发育，不利深层水浮游有孔虫的生存。滨海区，浮游有孔虫仅为少数几个浅层水的优势种，中层水浮游有孔虫不发育；内浅海区，浅层水浮游有孔虫占绝对优势，中层水浮游有孔虫处于次要地位，所含比例相对较小；外浅海区及陆坡半深海区，浅层水和中层水浮游有孔虫均较发育，中层水浮游有孔虫百分含量相对较高。崖１９－１－１井在上新世早中期曾出现外浅海至陆坡半深海区，为古水深最大时期     

富营养深水水库底栖动物群落与浮游生物相关性分析

底栖动物和浮游生物通过食物网发生复杂的交互作用,是水库生态系统物质循环的重要组分.南湾水库和汤浦水库均为存在富营养化现象的深水水库,具有较长时间的水温分层期.本文选取这两座供水水库为对象,比较其水体营养状态、底栖动物的群落结构、现存量和多样性.通过群落状态指数(IICS)定量评估底栖动物群落状态,并采用PLS模型、Spearman秩相关以及回归图探讨浮游生物各类群密度与IICS的关系.研究结果显示,南湾水库富营养程度高于汤浦水库,寡毛类在南湾水库占据优势地位,摇蚊类在汤浦水库数量上占优.南湾水库以收集者为主,其数量占比远高于汤浦水库.深水水库通常存在较强的热分层,富营养化会加重水库底部的缺氧或厌氧状态,导致底栖动物遭受周期性的缺氧扰动,影响种类多样性和现存量,改变浮游生物类群与底栖动物群落的相关性,因此底栖动物群落与浮游生物的相关性能够提供判断水库富营养化程度的重要信号,进而为水库管理方提供更多有价值的参考信息.     

涌浪对大气边界层风廓线的影响

以往研究表明, 涌浪存在时, 近海面大气边界层内Monin–Obukhov相似性理论(Monin–Obukhov Similar Theory, MOST)将会失效, 风廓线模型的建立需要考虑波致应力的影响。基于此, 本文首先研究了包含涌浪影响的Ekman模型和常通量层模型求解的风廓线。结果表明: 两种模型估算的风廓线均对涌浪的波衰减率系数c_β有较高的依赖性, 在c_β<–50时, 模型求解的风廓线均出现近海面风速极大值, 但科氏力对近海面风廓线的影响可以忽略。在不同的大气层结下, 分析发现海浪边界层(直接受波浪影响的区域)内风速明显小于海浪边界层之上MOST廓线在相同高度的外推值, 体现了涌浪引起明显的剪切增强。通过对比分析广东省茂名市附近海上观测平台的实测数据发现, 在涌浪存在时, MOST普遍无法描述风廓线; 统计分析表明常通量层模型估算的风廓线在8 m处的风速与实测数据高度一致。考虑以往研究基本局限于中性大气层结条件, 而涌浪经常显著影响着浮力作用明显的中低风速条件, 我们的研究将有助于理解不同大气层结条件下涌浪对风廓线的影响。     

Seasonal Stratification Characteristics of Vertical Profiles of Water Body in Lake Lugu

For the purpose of exploring seasonal stratification characteristics of water hydrochemistry, the seasonal dynamics and vertical thermal stratification of water temperature in Lake Lugu, the vertical profiles of water temperature (Temp), Electrical Conductivity (EC), Dissolved Oxygen (DO), pH and Chlorophyll-a (Chl-a) of Lake Lugu were monitored in January, April, July and October 2015, respectively. The results indicated that water body of Lake Lugu appeared thermal stratification in spring, summer and autumn, however, in winter, the water temperature in vertical direction was homogeneous. The thermocline was located between 10 and 25 m, nevertheless, it moved down to range from 20 to 30 m in autumn. In addition, water temperature in hypolimnion was maintained almost as a constant and consistent with annual temperature, indicating water body was stable all along. The results showed that the thermal stratification had some influences on vertical distributions of DO, EC, pH and Chl-a. The significant stratification of DO, EC and pH was found, especially in summer, DO and pH values in thermocline peaked due to greatly stable thermal stratification and temperature increase. In hypolimnion, DO concentration and pH value were very small. Moreover, Chl-a concentration was higher in the surface and lower in the bottom water, implying that human should be highly alter to prevent the emergence of a large area of algae in Lake Lugu. EC took on decreasing variation, besides, lower in the thermocline. While,Lugu Lake water salinity was lower and substantially constant (~ 0.10‰), without considering the effects of salinity, both in vertical sections and in epilimnion, thermocline and hypolimnion, there all existed a simple linear function of the relationship between EC andwater temperature, showing that Lugu Lake was affected by natural climate and keeps natural state.     

陕西省宝鸡市地质灾害发育特征

根据近7年来陕西省宝鸡市12区县地质灾害详细调查资料,总结宝鸡地区地质灾害主要类型、空间分布规律、发育特征及其危害性。研究结果显示,宝鸡市地质灾害发育类型主要包括滑坡、崩塌、泥石流及不稳定斜坡等4类,总体发育特征具有群发性、突发性、周期性和链生性。其中,滑坡和崩塌数量多、危害大,泥石流相对发育较少,不稳定斜坡多与崩塌相伴生,大多发展为崩塌灾害。每年汛期在强降雨作用下,都可能诱发表层小型滑坡和崩塌,特别是城镇居民房前屋后的小型黄土滑坡和崩塌,以及山区公路切坡导致的残坡积层滑坡崩塌频繁发生,是宝鸡市地质灾害群测群防和减灾防灾关注的重点。     

内宜高速K43+200～256段边坡治理措施

介绍了内宜高速公路K43＋200～256段边坡的治理方案、施工措施。该边坡的4个危岩体除了都采取预应力锚索外,还针对不同危岩体的特征采取了不同的治理措施：W 1预应力锚索＋裂隙封填;W 2预应力锚索＋岩腔封砌;W 3预应力锚索;W 4预应力锚索＋危岩体支撑。经过两年多时间的考验,证明该治理方案和措施是合理的。     

On the formation of couplet-style stratifications

Couplet-style stratifications refer to the sedimentary sequences that consist of alternating coarse-grain-dominated bed and fine-grain-dominated bed, with or without a sandwiched middle-sized bed. The formation mechanism is complicated due to the interplays of varying driving force （s）, sediment supply ＆ transport and topographic configurations. This paper presents a comprehensive overview of such characteristic bedforms, which emerge during the transport and deposition of non-uniform sediments. The leading formative models include water-stage variation, gravel-overpassing process, superimposition of bedload sheets and avalanching process （inverse grading）. Each process might produce similar or distinct sedimentological features with respect to grading, matrix content, grain attitude, bounding faces between beds and internal longitudinal/transverse geometry. The couplet-style stratified strata might play an active role in landscape evolution.     

基于分层假设的Green-Ampt模型改进

传统Green-Ampt入渗模型由于假设过于简化而限制了计算精度,针对这一问题,在分层假设的基础上对模型进行了改进:将均质入渗土壤分为饱和层、过渡层和干土层,采用Richards模型分析了不同入渗条件下各层的厚度以及各层内含水率和导水率的变化规律,结果表明,入渗条件一定时,过渡层占湿润层(包括饱和层和过渡层)比例会随湿润层厚度的增加线性减小,积水深度和土壤初始含水率分别会影响这一线性关系的纵轴截距和斜率,而土壤饱和导水率则对其没有明显影响;过渡层内土壤含水率分布为椭圆形曲线,而导水率随深度增加线性减小。在此基础上,通过引入湿润层的等效导水率并相应给出锋面吸力的计算方法,对传统Green-Ampt模型进行了改进。结果显示,改进后模型计算精度显著提高。     

三峡库区望霞危岩体孕灾地质环境条件分析

危岩体是一种典型的灾害地质体,其形成、变形与破坏受控于地质环境条件,地质基础要素在孕灾的过程中起着决定性作用,各基本地质要素与灾害形成的关系是研究危岩体变形规律和破坏机理的关键性问题。通过对三峡库区望霞危岩体区域地质构造作用分析,横石溪背斜构造解析,各类地质结构面发育特征统计和危岩体岩性组合方式及工程地质条件剖析,结合危岩体两次变形破坏过程,分析各因素对危岩体的形成及变形的关系。研究认为:孕育望霞危岩体的横石溪背斜雏形形成于印支期的隆升阶段,至燕山主期形成褶皱主体,后期则以继承性改造为主,危岩体的形成及孕育主要集中在背斜核部区域,枢纽位置尤为发育。控制危岩体变形的5条关键裂缝与顶部发育的"V"字形裂缝关系密切,其是在纵弯褶皱作用下背斜顶部脆性岩层受到强烈的拉裂影响,叠加台阶式层间滑动作用,形成与轴面近于平行的拉张裂缝。在望霞危岩体中发育多组地质结构面,其中原生结构面对各条关键裂缝及关键块体提供基础背景值,控制其规模、范围及变形强度。控制着变形关键部位特别是前缘软弱层变形位置、牵引区段及强烈程度。构造结构面主要控制关键裂缝的延伸方向、距离及样式,控制关键块体的变形方向,裂解范围及规模,掉块及崩裂位置,控制危岩体底部关键部位即压张裂缝的形成位置、张开度及位移方向。次生结构面主要控制后缘变形区,对各条关键裂缝控制其继承性变形,控制关键块体扩张,对岩体裂解破坏至关重要。同时,望霞危岩体在地层岩性上构成了典型的硬—软—硬岩性组合,为危岩体的变形提供了地质结构组合条件,其底部大面积的采空区控制着危岩体整体滑塌变形。     

南方水库季节性热分层消亡对沉积物铁和磷迁移的影响——以南宁市天雹水库为例

为了探究我国南方地区水库季节性热分层消亡前后沉积物铁和磷的迁移规律,于2019年11月-2020年1月对天雹水库多点位(浅水区和深水区)水体理化指标进行原位监测,并利用薄膜扩散梯度技术(DGT)高分辨率获取沉积物有效态铁和磷的浓度分布.结果 表明:(1)天雹水库沉积物有效态Fe和P浓度分别为4.67～18.72和0.0...