气候变暖对河南干旱气象灾害的影响及其对策

近年来,随着全球气候变暖,河南干旱灾害有"频发、加重、影响大"的趋势,在一定程度上影响了河南农业生产.本文分析了气候变暖对河南干旱灾害的影响,建议做好中长期天气预报,提高干旱预警水平;依靠科技与资金投入,提高抵御气象灾害的能力;建立农业救灾保险机制,合理安排种植布局.     

我国东南部地形对降水量分布的气候影响

利用１９５１－１９８０年地面测站网的年、月平均降水量资料，分析出我国东南部地区的地形对降水量分布存在着气候影响。其影响表现在浙闽山区的东西两侧山坡各有一条多雨带，南岭南北两侧山坡附近各有一个多雨区。从这些多雨带和多雨区出现的季节清楚地呈出出地形的向风坡在多雨带和多雨区形成中的作用。指出这些多雨带和多雨区是由地形对降水天气系统影响产生的向风坡多雨带。     

三维湖陆风的数值模式试验

利用地形坐标建立了一个三维湖陆风的预报模式，其中对边界层及模式层顶高度采用预报方程求解，对边界层参数作了较仔细的考虑。计算表明，模式运行十分稳定，对复杂地形条件下的湖陆风扰动系统有着很好的描述能力。     

Tracing mantle sources in the northern Lau back-arc basin by independent component analysis of basalt isotopic compositions

ABSTRACT

The northern Lau back-arc basin (NLB) lavas display a diverse geochemical nature caused by complex geological processes in this region. Independent component (IC) analysis was applied to investigate the nature of mantle sources in the NLB, based on a compiled geochemical data set from the NLB, central-southern Lau Basin (C-SLB), Pacific and Indian Ocean ridges, and Samoan islands. We identified three ICs in the five-dimensional space of Sr-Nd-Pb isotopic ratios, which can account for 96.5% of the isotopic variance. The correlations between the ICs and the incompatible trace elements ratios were further used to examine the origin of these ICs. The first IC (IC1) separates Samoan islands (IC1 < ?1) from the other groups, and shows negative correlation with (La/Sm)_N ratios. The second IC (IC2) discriminates mid-ocean ridge basalts (MORBs) from Pacific (IC2 > 0) and Indian (IC2 < 0) Ocean ridges as well as the C-SLB (IC2 > 0) and NLB (IC2 < 0) lavas. IC2 correlates positively with Ba/Th ratios. The third IC (IC3) distinguishes MORBs (IC3 > 0) and back-arc basin lavas (IC3 < 0), and displays a negative correlation with Th/Nb values. On a regional scale in the NLB, there is a broad increase in IC1, IC2, and IC3 from the north to the south. Only IC3 presents obvious decrease from the west to the east, i.e. with decreasing distance from the arc. The geochemical nature and the statistical properties of these ICs suggest that IC1 is related to an enriched mantle component most likely from the nearby Samoan plume, and the IC2 corresponds to a fluid-rich component from the subducting Pacific slab. The IC3 may represent partial melt of recycled subducted sediment or recycled continental crustal materials. The geographic distribution of three ICs supports that the relatively recent mixing of Samoan plume materials with the subduction-metasomatized back-arc mantle may be responsible for the observed geochemical diversity in NLB lavas.     

A study of the contribution of mass elevation effect to the altitudinal distribution of timberline in the Northern Hemisphere简

Alpine timberline, as the ＂ecologica tion of scientists in many fields, especially in transition zone,＂ has long attracted the atten- recent years. Many unitary and dibasic fitting models have been developed to explore the relationship between timberline elevation and latitude or temperature. However, these models are usually on regional scale and could not be applied to other regions; on the other hand, hemispherical-scale and continental-scale models are usually based on about 100 timberline data and are necessarily low in precision. The present article collects 516 data sites of timberline, and takes latitude, continentality and mass elevation effect （MEE） as independent variables and timberline elevation as dependent variable to develop a ternary linear regression meteorological data released by WorldClim and model. Continentality is calculated using the mountain base elevation （as a proxy of mass elevation effect） is extracted on the basis of SRTM 90-meter resolution elevation data. The results show that the coefficient of determination （R2） of the linear model is as high as 0.904, and that the contribution rate of latitude, continentality and MEE to timberline elevation is 45.02% （p=0.000）, 6.04% （p=0.000） and 48.94% （p=0.000）, respectively. This means that MEE is simply the primary factor contributing to the elevation distribution of timberline on the continental and hemispherical scales. The contribution rate of MEE to timberline altitude dif- fers in different regions, e.g., 50.49% （p=0.000） in North America, 48.73% （p=0.000） in the eastern Eurasia, and 43.6% （p=0.000） in the western Eurasia, but it is usually very high.     

冬季亚欧500hPa高度与下表面温度异常的大尺度相关型

使用NCEP／NCAR再分析资料，分析了冬季欧亚地区500hPa高度距平场与下表面温度距平场间的大尺度相关空间型，结果表明，两个场整体相关程度远高于随机水平，得到4对显著的耦合空间型，解释两场间协方差平方和的86％和各自方差的58％和38％，反映500hPa环流两种不同纬带的纬向环流异常和两种不同形态的经向环流异常，两个场距平之间的配合是受静力平衡关系支配的，秋季的表面温度异常能给出中低续500hPa高度距平符号的信息。     

准噶尔盆地玛湖凹陷夏子街扇区三叠系百口泉组沉积演化特征*

玛湖凹陷是准噶尔盆地最具规模的油气聚集带与勘探区,发育以砾岩为主、具有较强非均质性的粗粒沉积复杂地层。对粗粒沉积体的精细刻画有助于研究沉积体内部的非均质性特征。应用储层构型分析法,结合研究区岩心、测井、录井资料,对玛湖凹陷夏子街扇区三叠系百口泉组沉积体内部9个级次构型要素的几何形态、大小、方向以及相互之间的叠置关系进行了表征,识别出12种岩石相类型以及10种由岩石相组合而成的沉积微相类型。通过分析沉积微相在垂向、平面上的不同组合特征,扇体的类型受沉积环境影响发生变化,逐渐由冲积扇、河流扇转换为扇三角洲,整体反映了湖平面上升或沉积物供给量逐渐减小的沉积背景。分析夏子街扇区各期次的扇体特征,包括长轴、短轴距离、长轴短轴比、扇根与扇缘厚度变化、扇体坡度变化、扇体最大粒径变化等,认为扇体顺物源方向有以下变化趋势: 沉积物粒径大小随河道搬运逐渐减小,减小的幅度受扇体坡度影响,坡度越陡沉积物粒径减小的越快;河道数量减少,流量降低;河道沉积物在横向和纵向上的连通性逐渐降低;砂岩、砾岩厚度逐渐减小,泥岩厚度逐渐增加,湖相沉积变得较为发育。总结玛湖凹陷百口泉组的各期次扇体共可归纳出6种扇体模式: 冲积扇、冲积—河流扇、河流—末梢扇、河流扇—扇三角洲、扇三角洲、大型河流扇。     

松辽盆地徐深气田营城组火山岩储层三维地质建模技术

针对徐深气田投产的开发井产能较低、低效井较多、成本高、储量动用程度低和经济效益较差的实际,本文提出了地震、地质和测井等多学科综合精细地质建模技术研究的新思路,通过精细建立地震速度模型、构造模型、古地貌模型、火山岩相模型、储层参数随机预测模型、储层发育概率预测模型和裂缝模型等优选储层发育的有利部位,优化设计了6口水平井,初步形成-套深层火山岩气藏三维地质建模技术.研究成果在SS-H1井、XS1-H1井和XS1-H2井随钻地质导向中发挥了重要作用,取得了比较好的实际应用效果.     

渭河宝鸡峡全新世特大洪水水文学研究

通过深入的考察,在渭河宝鸡峡河段发现典型的全新世古洪水滞流沉积地层剖面,并进行了古洪水沉积学和水文学研究。对于采集的序列样品,进行粒度成分、磁化率、烧失量、CaCO3含量等分析,从沉积学角度证明了剖面上覆盖在古土壤S0顶部的沉积物为典型的古洪水滞流沉积层。根据其地层结构及其与流域内其他剖面的对比,结合其所含古文化层考古学年代和OSL断代数据等,确定渭河上游在3200～3000aB.P.发生了3次特大洪水事件。利用古水文学原理恢复其水位,并且利用水位-流量关系模型,计算出古洪水洪峰流量为22560～25960m3/s。 这个结果大大延长了洪水水文数据序列,从而能够建立渭河万年尺度洪水流量-频率关系,对于防洪减灾、水能源和水资源开发具有重要的应用价值。该成果揭示出万年尺度大暴雨洪水与气候变化的关系,丰富了全球变化的区域响应理论。     

甘肃南部又发现一处天然大溶洞——黄爷洞

黄爷洞（33°05′N,105°00′E）位于甘肃省陇南市武都县安化镇马家沟村东北2km处,洞口海拔约1650m。初步探测洞长约2000m,洞穴顶板覆盖层厚约150m。洞穴发育受到山体EW向断裂控制,洞身整体为EW走向。洞内宽约1～9m,一般在2～3m之间;洞内高约0.5～10.0m,一般在3～5m之间。该洞是继武都万象洞[1,2]之后发现的又一大型溶洞。