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1.
喀喇昆仑公路沿线地表水理化特征分析   总被引:2,自引:0,他引:2  
研究喀喇昆仑公路沿线地表水环境基本特征,为公路改扩建施工中开展水环境保护提供支持.2008年9月-2009年10月在喀喇昆仑公路沿线的印度河、洪扎河和红其拉甫河采集地表径流样,分析了样品中pH值和悬移质浓度,现场监测了水体透明度.结果表明:所有样品的pH值介于6.7~7.5之间,悬移质浓度分布在0~1 841 mg.L-1之间,水体透明度在2~107 cm.公路沿线地表径流的pH值基本呈中性,pH值的变化受补给的冰川融水pH值的时空变化规律影响;地表径流中悬移质是影响水体透明度的主要因素.监测数据还显示,气温影响下的冰川融水径流形成的水文过程是悬移质时间变化的主要控制因素,3条河流中悬移质浓度存在明显的空间分布规律,其中红其拉甫河中上游河段水中悬移质浓度含量较低,是喀喇昆仑公路改扩建工程施工中水环境保护的重点河段.  相似文献   

2.
天山乌鲁木齐河源1号冰川融水径流水化学特征研究   总被引:3,自引:2,他引:1  
冯芳  冯起  刘贤德  李忠勤  刘蔚  金爽 《冰川冻土》2014,36(1):183-191
2006年和2007年的整个消融期内,在天山乌鲁木齐河源1号冰川末端水文控制点逐日定时采集融水径流样品,对样品的主要可溶离子、pH、电导率EC、总溶解固体TDS和悬移质颗粒物SPM进行了分析. 结果表明:天山乌鲁木齐河源1号冰川融水径流离子类型为Ca2+-HCO3--SO42-,呈弱碱性. 融水径流中TDS变化受日径流量调节显著,表现为消融初期和末期浓度较高,消融强烈时浓度较低;SPM以细颗粒物质为主,各粒度组分含量变化幅度较大,且质量浓度SSC年内变化与TDS呈相反的变化趋势. 融水径流中离子组成主要受岩石风化作用影响,离子摩尔比值和Piper图分析表明,控制冰川径流离子组成的主要过程是碳酸盐、黄铁矿和长石类矿物风化作用.  相似文献   

3.
基于2012年消融期6~9月在祁连山老虎沟12号冰川采集冰川融水径流样品,分析探讨冰川融水中粉尘颗粒物对融水理化性质的影响。结果表明,粉尘特征在消融期的变化很好地反映了冰川消融过程,融水中粉尘浓度和粒径众数在冰川强烈消融期的7月份表现为最高。粉尘体积粒径分布主要包括大气气溶胶超细颗粒(0~3.0μm,主要为PM 2.5),大气粉尘颗粒(3.0~20μm),以及局地源的粗颗粒(20~100μm);对雪冰消融释放的粉尘部分(3.0~20μm)粒径分布正态拟合结果说明,融水中粉尘颗粒物有很大部分来源于积雪中的粉尘运移所致。同时,融水中化学离子相对组成及其浓度消融期变化都与粉尘有较好的一致性,意味着粉尘对融水化学要素有重要影响。此外,pH值和电导率(EC)消融期的变化也反映了粉尘对融水物理指标的影响。在粉尘浓度较高时,融水pH值和电导率也表现出高值;融水径流中的悬移质颗粒物(SPM)浓度和溶解质固体(TDS)浓度具有较为一致的变化过程,反映了粉尘对于融水中溶解质含量也有较大影响。  相似文献   

4.
基于2012年消融期6~9月在祁连山老虎沟12号冰川采集冰川融水径流样品,分析探讨冰川融水中粉尘颗粒物对融水理化性质的影响。结果表明,粉尘特征在消融期的变化很好地反映了冰川消融过程,融水中粉尘浓度和粒径众数在冰川强烈消融期的7月份表现为最高。粉尘体积粒径分布主要包括大气气溶胶超细颗粒(0~3.0 μm,主要为PM 2.5),大气粉尘颗粒(3.0~20 μm),以及局地源的粗颗粒(20~100 μm);对雪冰消融释放的粉尘部分(3.0~20 μm)粒径分布正态拟合结果说明,融水中粉尘颗粒物有很大部分来源于积雪中的粉尘运移所致。同时,融水中化学离子相对组成及其浓度消融期变化都与粉尘有较好的一致性,意味着粉尘对融水化学要素有重要影响。此外,pH值和电导率(EC)消融期的变化也反映了粉尘对融水物理指标的影响。在粉尘浓度较高时,融水pH值和电导率也表现出高值;融水径流中的悬移质颗粒物(SPM)浓度和溶解质固体(TDS)浓度具有较为一致的变化过程,反映了粉尘对于融水中溶解质含量也有较大影响。  相似文献   

5.
慕士塔格卡尔塔马克冰川作用区的水文与水化学特征   总被引:7,自引:2,他引:7  
利用2003年6月1日~8月25日实测的水文数据,分析了慕士塔格峰卡尔塔马克冰川融水径流的变化特征.卡尔塔马克冰川融水径流主要集中在6~8月,其存在着明显的日变化过程,融水径流受控于温度及降水要素.同时,对8月10~23日采集的冰川径流样品及部分降水样品的pH、EC(电导率)和主要离子(Na+,K+,Ca2+,Mg2+,Cl-,NO3-,SO42-,未检测降水样品的离子含量)的测定结果进行了分析讨论.径流样品略偏碱性,pH和EC呈正相关关系.SO42-和Ca2+是所测离子中主导的阴阳离子.除NO3-外,样品中各离子含量具有一致的变化特征;各离子浓度与流量或水位具有相反的变化趋势.初步讨论了离子的来源,结果表明冰川融水中化学物质组分主要来源于地表.  相似文献   

6.
祁连山北坡流域冰川物质平衡波动及其对河西水资源的影响   总被引:16,自引:27,他引:16  
祁连山北坡各流域发育有现代冰川 2 166条 ,总面积 13 0 8km2 ,冰储量 60km3,冰川融水补给河流约 8× 10 8m3·a-1,占河西地表总径流量的 11% .近 4 0a来 ,东段石羊河流域冰川物质平衡 (Bn)呈较大负平衡 ,Bn在 - 80~ - 12 0mm间 ;西段的讨勒河、疏勒河和党河流域冰川具正物质平衡 ,Bn在+ 5 0~ + 90mm ;黑河流域的冰川处于过渡区 ,其冰川物质平衡多年平均在 - 4 0~ + 4 0mm间 .冰川物质平衡的变化直接影响着河流径流的变化 ,洪水坝河、党河和昌马河的冰川融水补给率达 3 0~ 4 0 %以上 ,东大河、大渚马河、马营河和讨勒河的补给率在 12 %~ 14 %之间 ,而西营河和梨园河仅有 7%左右 .冰川物质平衡逐年变化显示 ,2 0世纪 5 0~ 70年代冰川以负物质平衡为主 ,80年代开始向正的平衡开始转化 ,90年代以正平衡为主 ,主要是冬季气温上升引起的降雪量增加的结果 .在全球气温变暖情景下 ,东段冰川物质平衡将呈增加的趋势 ,西段冰川物质平衡将呈下降的趋势 ,将使西段以冰川融水补给的河流径流增加 ,而东段石羊河流域径流下降明显 .  相似文献   

7.
塔什库尔干河流域是叶尔羌河中上游的主要支流之一,流域主要为高中山区,平均海拔4 630 m,高山区终年积雪,冰川发育.降水量的年内分配不均匀,暖季汛期降水量大而集中.塔什库尔干河流域发育有现代冰川862.45 km2,流域冰川覆盖率为8.64%.河流径流过程一般为双峰型,由春季的融雪径流和夏季的冰川融水径流形成,冰川融水占年径流的45%~55%,为典型的冰雪融水河流.塔什库尔干河的水能资源非常丰富,河道末段81 km的河道干流上有天然落差达1 020 m,在此河段上共规划了7个梯级水电站,总装机55.8×104 kW,目前尚有40.8×104 kW水电装机待开发.开展塔什库尔干河水能资源的开发利用,对增加能源供应安全、改善能源结构、保障能源安全具有非常重要的意义.  相似文献   

8.
何元庆  姚檀栋 《冰川冻土》2000,22(4):391-393
应用稳定同位素指示方法研究大气降水、冰雪和地表径流变化过程,是冰川学家、气候学家和水文学家共同感兴趣的课题之一[1~6]. 90年代开始,我国学者较详细地研究了青藏高原内陆大气降水中稳定同位素的分布和水文循环特征[7, 8],认为水汽来源是影响青藏高原降水中δ18O值的重要因素. 在大陆气团的影响下,青藏高原降水中δ18O与温度变化同步,即所谓“温度效应”. 但在源于海洋的暖湿气流影响下,特别在季风气候区,降水中δ18O与降水量和温度存在着负相关关系,即所谓“降水量效应”. 在我国西部的广大冰川分布区,占总面积的22%为南亚季风控制的温冰川(即海洋型冰川),过去由于种种原因对季风温冰川区稳定同位素的研究报道较少. 为填补这方面的科学研究空白,我们曾于1999年6月赴欧亚大陆最南的温冰川分布区玉龙山,首次开展了本区的冰芯研究[9]. 在钻取冰芯的同时,还全面采集了冰川区不同水体, 即表面积雪、夏季降水、冰川融水和冰川补给径流的样品,进行了δ18O的测定[10]. 结果表明,雪线以上积雪中的δ18O值比雪线以下积雪内的δ18O值为高,低海拔冰川补给径流比高海拔冰川融水的δ18O浓度为低,夏季降雨中δ18O值最低. 这种分布特征说明本区局部大气环流状况随时间和高度而变化,存在着季风气候区所特有的“降水量效应”. 为进一步证实该结果,我们于2000年7月又在玉龙山进行了更为详细的工作:在白水1号冰川积累区海拔5 000 m, 4 900 m和4 700 m处开挖了3个深度分别为3.1 m, 2.6 m和2.0 m的雪坑,采样77个; 沿海拔5 000~4 500 m采集了18个表面积雪样品; 雪线以下采集了数十个冰川融水样品; 分不同高度和日期采集了数十个夏季雨水样品; 此外,还沿冰川融水补给为主的白水河分段采集了水样数十个. 所采样品在中国科学院寒区旱区环境与工程研究所冰芯与寒区环境开放研究实验室用Delta Plus气体稳定同位素比质谱仪进行了δ18O的测定(表1),现将初步成果进行报道.  相似文献   

9.
《冰川冻土》2000,22(4)
应用稳定同位素指示方法研究大气降水、冰雪和地表径流变化过程,是冰川学家、气候学家和水文学家共同感兴趣的课题之一[1~6]. 90年代开始,我国学者较详细地研究了青藏高原内陆大气降水中稳定同位素的分布和水文循环特征[7, 8],认为水汽来源是影响青藏高原降水中δ18O值的重要因素. 在大陆气团的影响下,青藏高原降水中δ18O与温度变化同步,即所谓“温度效应”. 但在源于海洋的暖湿气流影响下,特别在季风气候区,降水中δ18O与降水量和温度存在着负相关关系,即所谓“降水量效应”. 在我国西部的广大冰川分布区,占总面积的22%为南亚季风控制的温冰川(即海洋型冰川),过去由于种种原因对季风温冰川区稳定同位素的研究报道较少. 为填补这方面的科学研究空白,我们曾于1999年6月赴欧亚大陆最南的温冰川分布区玉龙山,首次开展了本区的冰芯研究[9]. 在钻取冰芯的同时,还全面采集了冰川区不同水体, 即表面积雪、夏季降水、冰川融水和冰川补给径流的样品,进行了δ18O的测定[10]. 结果表明,雪线以上积雪中的δ18O值比雪线以下积雪内的δ18O值为高,低海拔冰川补给径流比高海拔冰川融水的δ18O浓度为低,夏季降雨中δ18O值最低. 这种分布特征说明本区局部大气环流状况随时间和高度而变化,存在着季风气候区所特有的“降水量效应”. 为进一步证实该结果,我们于2000年7月又在玉龙山进行了更为详细的工作:在白水1号冰川积累区海拔5 000 m, 4 900 m和4 700 m处开挖了3个深度分别为3.1 m, 2.6 m和2.0 m的雪坑,采样77个; 沿海拔5 000~4 500 m采集了18个表面积雪样品; 雪线以下采集了数十个冰川融水样品; 分不同高度和日期采集了数十个夏季雨水样品; 此外,还沿冰川融水补给为主的白水河分段采集了水样数十个. 所采样品在中国科学院寒区旱区环境与工程研究所冰芯与寒区环境开放研究实验室用Delta Plus气体稳定同位素比质谱仪进行了δ18O的测定(表1),现将初步成果进行报道.  相似文献   

10.
乌鲁木齐河源区水体和大气气溶胶化学成分研究   总被引:7,自引:6,他引:7  
对天山乌鲁木齐河源区采集的大气气溶胶、大气降水、积雪和径流样品中的主要离子(Cl-, NO+-3, SO+2-4, Ca2+, Mg2+, Na+, K+, NH++4, 其中降水中未测定NH++4)的测定结果进行分析和讨论. 结果表明, 所测阳离子当量浓度总和为所测阴离子当量浓度总和的2~8倍,认为缺失阴离子主要为HCO+-3,因此, HCO+-3, Ca2+是各种水体及气溶胶的主导阴、阳离子. 在采样时段各种水体中的离子浓度顺序为乌鲁木齐河源1号冰川径流>总控径流>空冰斗径流>降水>积雪, 积雪和降水样品的pH值接近中性,径流样品明显偏碱性. 通过比较不同水体中的离子浓度,了解到干、湿沉积、积雪淋溶对不同水体中离子浓度的改变及影响.  相似文献   

11.
International unity is becoming ever stronger in this country owing to an increasing similarity in the development of the cultural environment. This comprises the provision of all the country's republics with a sufficient number of schools, theatres, and other institutions and cultural information media in accordance with the needs of the population. An important part is played by the rise in ‘the general educational level, as well as the level of professional qualifications and skills. Among all the Soviet nations and nationalities, this rise being more rapid among formerly backward peoples. Prominent among the factors of internationalization is the progressive development of the nationalities’ cultural resources, while professional culture is being increasingly brought within the reach of the masses.The implementation of the nationalities policy promotes the all-round development of all Soviet nations and nationalities, their drawing together, the upsurge of the individual capabilities of every Soviet citizen.  相似文献   

12.
13.
Chronological analyses of correlations between certain global repeating events (mass extinctions of marine organisms, meteorite impacts, and flashes in the frequency of geomagnetic reversals) during the Phanerozoic Eon and the motion of the solar system in the Galaxy are presented for five rotationally symmetrical models for the regular Galactic gravitational field. Thirteen of sixteen mass-extinction events can be described by a repetition interval of 183±3 million years. This is in agreement with the anomalistic period (interval between two subsequent passages of the Sun through the apocenter of its Galactic orbit) in the model of Allen and Martos. The positions of the minima and maxima in Gaussian functions approximating the frequency distribution for geomagnetic reversals also agree with the times of passage of the Sun through the apocenter and pericenter, respectively, of its Galactic orbit in this model. The maximum in the distribution of the deviations of the dates of mass extinctions from the nearest dates of impacts of large, crater-forming bodies is close to zero, providing evidence that many such events are correlated. As a rule, extinctions follow impact events. The impacts of large bodies have occurred most often when the solar system passes through the Galactic plane, while mass extinctions occur more often at some distance from the Galactic plane (about 40 pc). As a rule, intervals of increases in the frequency of geomagnetic reversals coincide with dates of impacts of large bodies. At the same time, these intervals do not show a clear correlation with the dates of mass extinctions. The intensity of mass extinctions, like the energy released by impacts, is consistently higher in periods when the Sun is moving from the apocenter toward the pericenter of its orbit, than when it is moving from the pericenter toward the apocenter. Thus, there is evidence for a variety of relationships between repeating global events in the Phanerozoic and the motion of the Sun in the Galaxy. Long-period variations in the frequency of geomagnetic reversals are correlated with the orbital motion of the Sun, and increases in the frequency of geomagnetic reversals are correlated with impacts. Mass extinctions are correlated with the impacts of large bodies, whose motions may have been perturbed by clouds of interstellar material concentrated toward the Galactic plane and by the shock front associated with the Perseus spiral arm, through which the solar system passes. The velocity of the Sun relative to the spiral pattern is estimated.  相似文献   

14.
It is known from observations that the center of mass of the Moon does not coincide with the geometric center of its figure, and the line connecting these two centers is not aligned with the direction toward the center of the Earth, instead deviating toward the Southeast. This stationary deviation of the axis of the inertia ellipsoid of the Moon to the South of the direction toward the Earth is analyzed. A system of five linear differential equations describing the physical libration of the Moon in latitude is considered, and these equations are derived using a new vector method taking into account perturbations from the Earth and partly from the Sun. The characteristic equation of this system is obtained, and all five oscillation frequencies are found. Special attention is paid to the fifth (zero) frequency, for which the solution of the latitude libration equations are stationary and represents a previously unknown additional motion of the rotational axis of theMoon in a cone with a small opening angle. In contrast to the astronomical precession of the Earth, the rotation of the angular-velocity vector is in the positive direction (counter-clockwise), with the period T 3 = 27.32 days. On this basis, this phenomenon has been named “quasi-precession.” This quasi-precession leads to a stationary inclination of the major axis of the inertia ellipsoid of theMoon to the South (for an observer on Earth), making it possible to explain one component of the observed deviation of the center of mass of the Moon from the direction toward the Earth. The opening angle of the quasiprecession cone is approximately 0.834″.  相似文献   

15.
从榴辉岩与围岩的关系论苏鲁榴辉岩的形成与折返   总被引:4,自引:1,他引:4       下载免费PDF全文
位于华北和扬子两板块碰撞带中的苏鲁榴辉岩形成的温压条件不但是超高压,而且是高温。榴辉岩的PTt轨迹表明其为陆-陆磁撞俯冲带的产物。榴辉岩的区域性围岩花岗质片麻岩为新元古代同碰撞期花岗岩,榴辉岩及其他直接围岩皆呈包体存在于其中,并见新元古代花岗岩呈脉状侵入榴辉岩包体中。区域性围岩新元古代花岗岩的锆石中发现有柯石英、绿辉石等包裹体,表明新元古代花岗岩的组成物质也经受过超高压变质作用,且榴辉岩与围岩新元古代花岗岩的锆石U-Pb体系同位素年龄基本相同。但新元古代花岗岩所记录的变质作用和变形作用期次(或阶段)却少于榴辉岩。椐上述可得如下推断:超高压榴辉岩与新元古代花岗岩岩浆是同时在碰撞带底部(俯冲板块前部)形成的;榴辉岩的第一折返阶段是由新元古代花岗岩岩浆携带上升的,其第二折返阶段是和新元古代花岗岩一起由逆冲及区域性隆起而上升,遭受剥蚀。  相似文献   

16.
某高速公路下伏煤矿采空区稳定性分析   总被引:10,自引:0,他引:10  
在论述某高速公路下伏砦脖煤矿采空区地质、采矿和工程地质特征的基础上, 进行了稳定性数值模拟分析, 定性与定量地分析与评价了该煤矿采空区的地表变形特征及稳定性。研究结果表明: 该煤矿采空区的变形尚未完成, 对拟建的高速公路将产生很大的危害, 必须采取相应的工程治理措施。   相似文献   

17.
摩擦桩基桩土间极限摩阻力取值问题探讨   总被引:1,自引:0,他引:1  
陈银生 《世界地质》1999,18(1):54-59
通过对广珠东线高速公路横沥大桥的试桩及土体的工程地质条件分析,总结出影响摩擦桩基桩土间极限摩阻力取值的一般问题以及解决问题的方法和措施。  相似文献   

18.
19.
In order to characterise the influence of the heavyrains on the observed landslides during the 1996–1997hydrological cycle, rainfall records for the last 100years are analysed from 104 stations in easternAndalusia. Regarding the amounts of rain recordedbetween October 1996 and March 1997 in the 104stations studied, 31 presented new all-time records;15 presented values that were 80–100% of thepre-1995 record; 49 stations, 80–50%; and 9stations, < 50%. A map has been devised of thesusceptibility of the materials through which thesouth-eastern Andalusian road network crosses,together with an inventory of the damage caused byinstability phenomena on banks and cuttings of theroad network during the winter of 1996–1997. Therelationships between the rainfall during the studyperiod, the damage caused to the road network and thesusceptibility of the materials affected are analysed.The results indicate that there is a clearcorrespondence between the rainfall recorded and thesusceptibility of the materials with the inventorieddamage. It is concluded that the widespread seriousdamage caused in early 1997 to the roads andsurrounding areas in the Alpujarra region and thecoast of the Province of Granada was mainly caused bythe extraordinarily heavy rains. However, considerablyless damage was observed where the susceptibility ofthe terrain is low, thus highlighting the extremeusefulness of terrain-susceptibility maps for riskprevention and territorial planning.  相似文献   

20.
We first re-examined the apparent polar wander curves for stable Eurasia and Africa since the Triassic. These curves were then combined together with curves of North and South America according to the kinematics of the Atlantic ocean and a synthetic polar wander curve was given. Then, most of the paleomagnetic results from the Tethys mobile belt, from the Atlantic to the Pamirs, were analysed.Several groups of plates, microplates and blocks can be seen. First, relatively stable regions like Maghreb and Sicily, which have not moved much. Then we have a group formed by Iberia, Sardinia, Italy and, to a lesser extent, Corsica and the Western and Central Alps. For these blocks, movements are anticlockwise rotations chiefly driven by the anticlockwise rotation of Africa, but they are sometimes stronger.To the east, a major change takes place. The north of the Aegean Sea and the Ionian zone are clockwise rotated and these rotations are recent: Oligocene-Miocene for the first part, Pliocene to the present for the second part.A major problem arises in Turkey, Caucasus and Iran. Paleomagnetic results indicate a position far to the south of Eurasia, and, at the same time, geological evidence is in favour of a position close to Eurasia. We discuss these discrepancies.  相似文献   

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