青藏高原水文模拟的现状及未来

介绍了青藏高原水文模拟的研究现状和发展趋势。水文模拟是研究水文过程的主要手段,可为流域水资源管理及防灾减灾提供理论和决策支持。国际上第一代水文模型为"集总式",第二代水文模型为"分布式",但它们大都以描述降水—产流的水分输移为主("水圈"),未仔细考虑陆—气水热交换中植被的调节作用("生物圈—大气圈")。近10年来,在气候变化的背景下,随着大气科学以及生态学的蓬勃发展,分布式水文模型开始描述生物圈—大气圈相互作用;通过改进陆—气间的水热交换过程以及植被的生理过程,实现了对流域水圈—生物圈—大气圈的综合模拟。然而,针对显著受冰冻圈过程影响的青藏高原,需要深入研究冰冻圈与其他圈层(水圈/生物圈/大气圈)的相互作用机理,并实现其在水文模拟中的参数化,以提升区域水资源和水灾害的预测能力。     

POSITIVE INVERSION STRUCTURE OF THE CENTRAL STRUCTURE BELT IN TURPAN-HAMI BASIN

The central structure belt in Turpan-Hami basin is composed of the Huoyanshan structure and Qiketai structure formed in late Triassic-early Jurassic, and is characterized by extensional tectonics. The thickness of strata in the hanging wall of the growth fault is obviously larger than that in the footwall, and a deposition center was evolved in the Taibei sag where the hanging wall of the fault is located. In late Jurassic the collision between Lhasa block and Eurasia continent resulted in the transformation of the Turpan-Hami basin from an extensional structure into a compressional structure, and consequently in the tectonic inversion of the central structure belt of the Turpan-Hami basin from the extensional normal fault in the earlier stage to the compressive thrust fault in the later stage. The Tertiary collision between the Indian plate and the Eurasian plate occurred around 55Ma, and this Himalayan orogenic event has played a profound role in shaping the Tianshan area, only the effect of the collision to this area was delayed since it culminated here approximately in late Oligocene-early Miocene. The central structure belt was strongly deformed and thrusted above the ground as a result of this tectonic event.     

软土地基桥台位移病害分析及防治措施

软土地基桥台存在三方面的主要隐患:桥头与路堤具有较大的沉降差;桥台倾斜或桥台底部出现垂直裂缝;桥台向河心移动。软土层地质结构及物理地学性质、桥台形式、勘探与施工质量是影响桥台位移的主要原因。淮安市高等级公路建设的桥梁建设实践表明,应从设计施工、养护方面采取综合防治措施,使损失减到最低限度。     

江西省大地热流与铀矿关系的初步研究

本文根据江西省大地构造、铀矿分布和大地热流实测资料,证明大地热流异常和铀矿均受深大断裂和深部构造变异带的控制,铀矿化能在一定程度上引起热流异常,并据此初步探讨了根据大地热流异常寻找铀矿床的可能性。     

南京下蜀土的地球化学特征及其物源指示意义

风尘堆积的物源研究对于揭示物源区的环境演化状况、重建古风场强度和古大气环流格局等都具有重要的意义。目前长江下游地区下蜀土的物质来源问题仍然存在争议。为了解决这一争议问题,本文以南京泰山新村下蜀土剖面为研究对象,开展了系统的地球化学研究。通过对南京下蜀土的常量元素、微量元素、Nd同位素进行测试,并与黄土高原同期黄土进行对比分析,探讨其对长江下游下蜀土的物源指示意义。南京下蜀土与北方黄土具有相似的常、微量元素UCC标准化曲线和稀土元素球粒陨石标准化曲线,但是它的Zr、Hf含量较高,Tl、Pb含量较低,且具有较高的SiO2/Al2O3、TiO2/Al2O3、Nb/Ta和GdN/YbN,较低的SiO2/TiO2、Zr/Hf、Y/Ho、Lu/Hf和εNd(0)值,说明南京下蜀土的物质来源明显有别于黄土高原黄土。南京下蜀土与长江中游下蜀土在地球化学特征方面有较多的相似性,指示其物质来源与中游下蜀土的物质来源相似,主要来源于长江中下游地区的松散沉积物。     

土壤酸化研究进展

环境酸化是全球变化中的一个重要内容，土壤酸化是环境酸化的一个重要方面。综述了土壤酸化研究的进展，主要有土壤酸化的概念、表示方法、研究方法、土壤酸化敏感性、土壤酸化与元素淋失的关系等方面。最后提出了进一步研究的方向     

柴达木盆地深层钾盐察ZK02孔施工工艺

柴达木盆地察汗斯拉图矿区蕴藏着极为丰富的钾盐类矿产资源。钾盐察ZK02孔设计1500 m,钻遇地层为新近系盐湖相沉积地层。在钻进过程中易产生缩径、造浆、掉块、坍塌等现象,钻遇盐岩层或含钙、镁离子盐水入侵时,钻井液性能易发生变化,给钻探施工带了困难。根据盐矿钻孔地质条件和技术要求,设计3级口径的钻孔结构。在施工中,针对巨厚层砂砾碎屑岩的特点,选择加重卤水钻井液护壁,起到了安全护壁效果,并采用研制的卤水钻井液混合搅拌器,提高了配浆速度,保证了钻井液性能和质量。卤水钻井液和卤水钻井液混合搅拌器的使用,为柴达木盆地深层卤水钾盐矿区的钻探施工探索出了快速配制钻井液提供了借鉴。     

云南羊拉铜矿床成矿流体特征及成矿过程

云南羊拉铜矿床位于金沙江构造带中部,是中-晚三叠世金沙江洋盆向西俯冲闭合碰撞造山过程中形成的一个大型铜矿床。矿体多呈层状、似层状顺层产出,但明显受层间破碎带和滑脱带控制。从流体包裹体研究入手,讨论了该矿床成矿流体的特征、演化以及流体不混溶(沸腾)作用与成矿的关系。流体包裹体研究表明,干夕卡岩阶段(Ⅰ)、湿夕卡岩磁铁矿阶段(Ⅱ)、石英硫化物阶段(Ⅲ)以及方解石硫化物阶段(Ⅳ)中发育多种类型的包裹体,主要为气液水两相包裹体和含子矿物多相包裹体,纯液相水包裹体次之,少见纯气相有机质包裹体。其中,含子矿物多相包裹体发育于Ⅰ阶段石榴石、Ⅱ阶段绿帘石,尤其是Ⅲ阶段石英中。Ⅰ、Ⅱ阶段成矿流体具有高温、高盐度特征,均一温度分别为413~593 ℃和336~498 ℃,盐度分别为19.1%~49.7% NaCleq和15.7%~53.3% NaCleq;Ⅲ阶段成矿流体均一温度为148~398 ℃,并具有低盐度(2.1%~9.6% NaCleq)与高盐度(35.5%~65.3% NaCleq)共存的特征;Ⅳ阶段成矿流体具有低温(132~179 ℃)、低盐度(3.4%~10.4% NaCleq)特征。根据流体包裹体的微观特征并结合矿区的宏观地质特征,认为流体不混溶(沸腾)是导致本矿区金属沉淀成矿的主要机制。     

The streamflow trend in Tangwang River basin in northeast China and its difference response to climate and land use change in sub-basins

In this study, the hydro-climatic trends (1964–2006) of Tangwang River basin (TRB) were examined using the Kendall’s test. Moreover, the impacts of climate variability and land use change on streamflow in each sub-basin were assessed using the Soil and Water Assessment Tools (SWAT) model. The results indicated that annual mean flow and peak flow showed insignificant decreasing trends (?0.14 m³ s^?1 year^?1, 1 %; ?8.67 m³ s^?1 year^?1, 40 %), while annual low flow exhibited a slightly increasing trend (0.02 m³ s^?1 year^?1, 11 %). Correspondingly, the annual precipitation for the entire basin decreased by 0.02 mm year^?2, while the annual means of daily mean, maximum and minimum temperature increased significantly by 0.07, 0.10 and 0.02 °C year^?1, respectively. On the other hand, with the implementation of “Natural Forest Protection Project” and “Grain for Green Project”, the forests in TRB totally increased by 744.5 km² (4.00 %) from 1980 to 2000. Meanwhile, the grasslands and the farmlands decreased by 378.0 km² (?1.98 %) and 311.9 km² (?1.63 %), respectively. Overall, land use changes played a more important role for the streamflow reduction than climate change for SUB1, SUB2 and SUB3, in which the primary conversions were from grassland, farmland and bare land to forests. Conversely, in SUB4, the influence of climate variability was predominant. The results obtained could be a reference for water resources planning and management under changing environment.