疏勒河上游径流组分及其变化特征定量模拟

气候变化背景下,西北干旱区内陆河流域的水文过程发生显著变化,制约着地区经济社会和生态建设的稳定发展。定量分析和评估高寒山区径流的变化,有助于加强西北地区水资源的规划管理,实现水资源的可持续利用,保障区域水安全。选取位于青藏高原东北边缘、祁连山西段的疏勒河上游作为研究区,利用包含冰雪消融模块的寒区水文模型分布式SPHY模型（Spatial Processes inHydrology model）对流域的径流过程进行定量模拟,根据模拟结果分析了疏勒河上游近45 a径流组成及径流与各组分的变化特征。结果表明：（1）率定期日径流和月径流模拟的Nash效率系数分别为0.62和0.86,验证期达到0.79和0.95,模拟的月径流与实测月径流过程基本一致;（2）径流由四部分组成,冰川径流占总径流的年平均比例为30.5%,融雪径流的占比为12.9%,降雨径流的占比为13.5%,基流的占比为43.1%;（3）由于气温升高、降水增多,冰川径流与降雨径流均呈增加的趋势,平均增加幅度分别为4.66×10⁶ m³·a^-1和2.46×10⁶ m³·a^-1,融雪径流呈减少的趋势,平均减少幅度为1.01×10⁶ m³·a^-1;（4）近45 a年径流增加了69.6%,冰川融水对流域径流增加的贡献率达到48%,非冰川区降水增加的贡献率达到52%。     

气候变暖背景下极端气候对青海祁连山水文水资源的影响

利用青海祁连山区极端气候要素和青海湖、哈拉湖及主要河流的水文资料,研究表明：冷夜日数（10%）呈显著减少趋势,暖夜日数（90%）呈显著增加趋势;年大风日数显著减少;年降水量21世纪初增加趋势最为显著并发生突变,降水量增加幅度中西段大于东段;≥ 5 mm、≥ 10 mm、≥ 25 mm年降水日数呈显著增加趋势,进入21世纪后更为明显,而≥ 0.1 mm年降水日数呈减少趋势;年平均大风日数与湖泊水位、河流流量变化呈负相关,大风天气的减少,可以缓解湖面和土壤因蒸发而导致的水分损失,对植被的改善可增加径流的产生,流入湖泊的流量增加;降水量与湖泊水位、河流流量呈正相关,受21世纪降水量增加的影响青海湖水位逐年上升,共上升1.67 m,达到20世纪70年代末的水位,中西部主要河流流量近几年也达到最大值,而东段流量增加不明显;祁连山区≥ 5 mm、≥ 10 mm、≥ 25 mm年平均降水量与湖泊、河流流量变化呈正相关,各量级年降水量对湖泊水位、河流流量的增加贡献显著。     

济阳坳陷义和庄凸起东部燕山期构造负反转及层序地层样式响应

通过钻井、测井与地震数据,依据不整合面分析、断层活动速率分析与地层的"负向结构"分析,在义和庄凸起东部燕山期内识别出一期发生于中晚侏罗世之交的构造负反转,并据此将义和庄凸起燕山期划分为早期与晚期两个阶段.通过单井与连井层序地层分析,分别建立了燕山早期与晚期的层序地层样式,两者在层序结构及内部沉积充填等方面表现出巨大差异.早期层序地层不具有显著的沉积厚度分异,且格架内部充填河流相沉积;晚期因构造负反转而形成小型拉张断陷盆地,沉积厚度分异明显,内部以扇三角洲沉积充填为主,呈现出对构造负反转的显著响应.燕山期构造-层序地层学的研究可为中国东部其他具有相似构造背景盆地前新生代的油气勘探提供借鉴.     

阿尔金南缘阿克提山岩体锆石U- Pb定年、Hf同位素特征及构造意义

阿克提山花岗岩体位于阿尔金断裂南缘,其形成时代与区域内其他花岗岩体差异较大,该岩体走向明显地受阿尔金断裂带分支断裂控制。锆石LA-ICP-MS U-Pb年代学分析表明,该岩体结晶年龄约为262Ma,其形成可能与南阿尔金地区在华力西期-印支期发生的大规模线性构造运动有关。岩体的岩性主要为石英闪长岩、花岗闪长岩,其暗色矿物以角闪石、黑云母为主,岩石A/CNK值均小于1.1,显示准铝质—弱过铝质特征,属于高钾钙碱性系列;大离子亲石元素Rb、Th、K相对富集,高场强元素Nb、Ta、P、Sr、Ti明显呈负异常;稀土元素配分曲线具有中等负Eu异常,δEu的平均值为0.73,(La/Yb)_N平均值为14.57,说明该花岗岩体岩浆部分熔融程度较高。根据岩石学及地球化学特征可判断该岩体为I型花岗岩。锆石Lu-Hf同位素分析表明,锆石ε_(Hf)(t)值为+1.46～+9.14,均为正值,二阶段模式年龄的峰值平均为943Ma,表明其源岩主要为新元古代新生地壳物质的部分熔融。阿尔金断裂在印支期的走滑运动是从地壳深部的韧性变形开始的,随后在浅地表发生脆性断裂形成大规模走滑断裂带。阿克提山岩体的形成与地壳深部减压熔融有关。     

Progress of Long-Chain Alkyl Diols in Marine Environmental Reconstruction

Long-chain alkyl diols contain an alkyl chain with alcohol groups at C1 and at the middle position of carbon chain, which exist widely in seas, rivers and lakes. It has been proven that these compounds are relatively resistant to degradation and have an extended occurrence in the geological record. In addition, they are relatively easy to identify. Therefore, long-chain alkyl diols can be used as potential biomarkers to trace the past change in paleoenvironment and paleoclimate. Although the sources of long-chain alkyl diols are still uncertain, the studies indicate that 1, 13 and 1, 15-diols are mainly produced by eustigmatophytes, while 14-diols are mainly from diatom Proboscia. So far, some proxies based on long-chain alkyl diols have been established to indicate the change in diatom productivity, upwelling intensity, salinity, sea surface temperature, riverine organic matter input and surface seawater nutrient concentration, which are significant for paleoenvironmental reconstruction. Current research and application of long-chain alkyl diols proxies were summarized, which would be helpful for further studying the source of long-chain alkyl diols and the application of relevant proxies in China’s marginal sea.     

碱激发材料固化低液限粉黏土路用性能及抗冻融特性研究

以伊犁地区S315线蜂场至尼勒克段低液限粉黏土为研究对象,以碱激发材料为固化剂,对粉质黏土和其固化土开展了路用性能指标试验与冻融循环试验,并利用电镜扫描试验(SEM)与X射线衍射试验(XRD)研究了固化土的微观特征,探讨了碱激发材料对粉质黏土路用性能指标与抗冻融特性的影响.试验结果表明,固化土的无侧限抗压强度与抗剪强度...     

Did the “Autochthonous” European foreland of Corsica Island (France) experience Alpine subduction?

Despite the important role played by the Sardinia‐Corsica block in the reconstruction of the Western Mediterranean geodynamics, the extent of involvement of the “Autochthonous” European margin exposed in Corsica (France) (i.e., Hercynian Corsica) in the Alpine orogeny remains uncertain. Stratigraphic and sedimentological studies in the post‐Variscan deposits on the Hercynian Corsica are scarce and even scarcer are the structural and metamorphic constraints. To face these uncertainties, we present new stratigraphic, structural and metamorphic data from the area of Razzo Bianco, Central Corsica, where a complete sequence belonging to the European continental margin is exposed. Field and structural investigations demonstrate that the sequence represents the easternmost edge of the downgoing European plate. Metamorphic studies on the Eocene deposits indicate that the margin was buried at depth up to blueschist facies conditions and, subsequently, it was progressively exhumed mainly through the activation of oblique top‐to‐the NW shear zones.     

Rill flow resistance law under equilibrium bed‐load transport conditions

In this paper, a recently deduced flow resistance equation for open channel flow was tested under equilibrium bed‐load transport conditions in a rill. First, the flow resistance equation was deduced applying dimensional analysis and the incomplete self‐similarity condition for the flow velocity distribution. Then, the following steps were carried out for developing the analysis: (a) a relationship (Equation  13 ) between the Γ function of the velocity profile, the rill slope, and the Froude number was calibrated by the available measurements by Jiang et al.; (b) a relationship (Equation  17 ) between the Γ function, the rill slope, the Shields number, and the Froude number was calibrated by the same measurements; and (c) the Darcy–Weisbach friction factor values measured by Jiang et al. were compared with those calculated by the rill flow resistance equation with Γ estimated by Equations  13 and 17 . This last comparison demonstrated that the rill flow resistance equation, in which slope and Shields number, representative of sediment transport effects, are introduced, is characterized by the lowest values of the estimate errors.     

城市和城市群可持续发展指数研究进展

21世纪是城市的世纪,城市的高质量发展对区域和全球可持续发展至关重要。中国城市化发展迅速,城市化率从1978年的17.9%增加到2019年的60.6%,2030年将达到70%,大部分人口居住在城市。城市是中国经济发展的引擎,以全国近7%的土地面积生产了70%的国内生产总值(GDP),而城市群更是集聚了全国大部分城镇人口和GDP。因此,城市和城市群的健康与可持续性将决定中国未来发展的质量与进程。识别城市和城市群发展的程度、存在的问题以及国内外差距,亟需进行城市可持续发展的评价。本研究系统综述了城市可持续发展评价的思想与指标体系的发展历程,重点基于联合国可持续发展目标(SDG)框架考察了开展城市可持续发展评价的方法,提出了构建城市和城市群可持续发展指数的途径,并从平台构建、大数据基础、跟踪发布等方面提出了推进城市可持续发展指数评价建立城市发展“仪表盘”的思路。基于联合国SDG框架的城市和城市群可持续发展指数可为目标城市对标其他城市、开展不同区域城市的对比、找准发展目标与识别存在问题等方面提供重要支撑。     

中国东北地区冬季气温趋势及反相模态分析

利用1951—2010年我国东北地区共97个台站的逐月气温资料,应用trend-EOF和EOF分析方法研究了我国东北地区冬季气温的趋势模态和反相模态及其影响因子。trend-EOF的结果表明,东北地区均为一致型的趋势变化,trend-PC1有明显的年代际周期变化和更长期的上升趋势变化特征。去除全球变暖信号后的EOF分析结果表明:第一模态仍为全区一致型的空间分布,而第二模态的空间分布呈现南北反相型的分布特征,是东北冬季气温变化模态中极为重要的一部分,对应的时间序列有明显的年际周期变化,前两个模态可以解释总方差80%以上的变化。东北地区全区一致的上升趋势是在全球变暖大背景下发生的,既是对全球变暖的局地响应,同时全球变暖也使大气环流发生了变化,西伯利亚高压减弱,纬向环流增强,导致了东北地区冬季气温全区的上升趋势。赤道东太平洋的异常海温对第二模态的出现具有一定的预示意义,当太平洋出现典型的厄尔尼诺年海温距平场分布特征时,东北南部较常年偏暖,北部地区却较常年偏冷。