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利用NCEP/NCAR1980-1989年10年逐日00UTC、12UTC再分析资料及青藏高原降水、径流资料,研究了青藏高原雅鲁藏布江流域的水平衡特征,估算了雅鲁藏布江流域的蒸发、土壤和地下水含量。结果表明:雅鲁藏布江流域夏季是水汽辐合区,降水大于蒸发;秋末到次年春季是水汽通量辐散区,蒸发大于降水。降水主要集中在6～9月。径流的年际变化趋势同降水相近,径流主要是由降水补给的,径流峰值滞后降水峰值一个月。雅鲁藏布江流域土壤及地下含水量从1～6月逐渐减少,7月以后开始增加,10月是土壤及地下水最丰富的时段。20世纪80年代中期和后期降水、蒸发、径流等呈增长趋势,这同ENSO事件有关。 相似文献
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运用数值模拟建立青藏高原兹格塘错流域土壤、植被、气候等的空间和属性数据库;接着,借助分布式流域尺度水文模型（SWAT模型）,对兹格塘错1956—2006年间的流量进行模拟实验;最后,反演50年来兹格塘错流域水文过程,测试流域温度、降水和蒸发组合的敏感因子对湖泊水量变化的效应,探讨50年来湖泊水量对气候变化的响应。模拟实验的边界条件设置为自然地形、土壤、植被覆盖,其中土壤资料包括有机质含量、粒径等理化参数。模拟结果表明：兹格塘错的年平均流量为6.3m3/s,流量高峰集中在8月至10月,并且由于融雪补给的关系,3月出现另一个流量高峰;模拟结果与遥感解译所得到的结果吻合较好。敏感实验表明：兹格塘错流域内温度、降水和蒸发组合的敏感因子实验具有高原特征,即高原湖泊的水文过程和湖泊流量变化有着较为敏感的响应关系;兹格塘错流量受降水的影响最大,随着降水的增加,流量有所增加;在温度升高的情况下,流域蒸发量增加速度大,兹格塘错流量增加的效应不明显,而在冷湿模式下,流域蒸发量降低,兹格塘错流量增加显著。 相似文献
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《地下水》2020,(3)
柯克亚尔河流域地处中纬度欧亚大路腹地,远离海洋并受北部、西部天山屏障的阻隔,流域区域内气候差异明显。为全面研究流域的水文气象特征,选用部分邻近流域的水文站和气象站作为参证站,通过对柯克亚尔河流域降水、蒸发等典型气象特征进行分析,掌握了该区域降水的季节分布、降水量年际变化和流域河流水面蒸发的基本规律,结果可知:流域内形成降水水平分布不均,总趋势为水汽自西向东,自北向南减弱。多年平均降水量为180. 2 mm;变差系数Cv为0. 36,降水量年际变化不是很大,山区大于平原,垂直分布十分明显,而降水分布季节分配不均;流域河流水面蒸发规律年内变化不均,7月水面蒸发量最大月,约占年水面蒸发量的16. 7%,1月蒸发量最小,约占年水面蒸发量的0. 94%,水面蒸发主要集中在4-9月,约占年水面蒸发量的82. 5%。研究结果可以为进一步研究流域洪水发生规律,确保城市人民生命和财产安全,合理开发利用区域水资源,发展社会经济提供基础依据。 相似文献
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青藏高原中部地面蒸发量观测计算与特征分析 总被引：3，自引：1，他引：3
青藏高原中部地区地面蒸发过程主要发生于５－１０月，７月蒸发最为剧烈。与其它因子相比较，地面蒸发量与水面蒸发量相关关系最好，与潜在蒸发量相关关系次之。下垫面条件对地面蒸发量影响很大，冻结与冻结地表面蒸发量可相关２－３倍。与更为干旱的高原西部的天山地区的研究成果相比，该区稀量蒸发能力的指标的实际蒸发量均要高出许多。 相似文献
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耕层土壤含水量消长规律分析 总被引：4，自引：1，他引：4
利用濉溪县耕层土壤含水量和同期观测的降水量、蒸发量资料分析表明:耕层土壤含水量的消长与基期土壤含水量、期间降水量和蒸发量呈多元直线相关关系,其中耕层土壤含水量增加量主要取决于基期土壤含水量的高低和降水量的多少;土壤含水量减少量主要取决于蒸发量的多少和基期土壤含水量的高低。耕层土壤相对含水量在50%～65%之间,需降水或补充灌溉15.9～82.3mm的水量。降水效力与基期土壤含水量和降水量呈多元指数曲线关系,蒸发效力与基期土壤含水量呈指数曲线关系。耕层土壤含水量的消退呈“快—缓慢—滞缓”的变化过程。使耕层相对含水量达到80%以上的一次降水(过程)过后,连续9.2～39.6d无降水耕层相对含水量尚可维持在60%以上。 相似文献
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根据青藏高原中部那曲河流域1998年夏季测得的上下游中稳定同位素的日变化,并与同期观测的流域降水中稳定同位素比较,分析了河水中δ18O的变化特征,初步研究了该流域的稳定同位素水文循环过程.河水中δ18O的变化幅度远小于降水,它是降水中δ18O、降水量以及地表蒸发过程共同作用的结果.研究发现湖水对于稳定同位素变化起着显著的调节作用.河水中δ18O与流域降水中δ18O的差异可能反映了该流域强烈的地表和湖面蒸发作用. 相似文献
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1989年10月至1990年5月间的8个降水时段的对比测量表明,乌鲁木齐河源高山区空冰斗小流域内雨量器冬季测量的降雪量约为地面积雪测量所得实际降雪量的73%,二者的测量结果不具有一致性,因此,雨量器的测量值不能代表地面实际降雪量.在流域水量平衡和融雪径流计算中,必须首先修正降雪量测量的系统误差. 相似文献
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高寒草地植被覆盖变化对土壤水分循环影响研究 总被引：40，自引：8，他引：40
土地覆盖变化对流域水平衡的影响是流域水学和生态水学研究的关键问题之一。以黄河源区两个典型小流域为研究对象，通过对流域不同植被类型与植被覆盖土壤的水分含量、入渗过程、蒸散发特征的测定，研究了高寒草地植被覆盖变化对土壤水分循环的影响．结果表明：广泛分布于青藏高原河源区的高寒草甸草地，植被覆盖度与土壤水分之间具有显的相关关系，尤其是20cm深度范围内土壤水分随植被盖度呈二次抛物线性趋势增加；在保持其原有的植物建群和较高覆盖度时，土壤上层具有较高持水能力，降水通过表层向深层土壤的渗透速度缓慢，且具有较均匀的土壤水分空间分布，水源涵养功能明显；高寒草甸草地退化后的高山草甸土壤趋于干燥，持水能力减弱，即使进行人工改良以后，土壤水分含量与持水能力也不会有明显改善．保护河源区原有高寒草甸草地对于河源区水过程意义重大。 相似文献
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S. Viswanathan K. Surya Prakash Rao B. Mahabaleswar 《Journal of the Geological Society of India》2013,82(6):621-627
Komatiites are mantle-derived ultramafic volcanic rocks. Komatiites have been discovered in several States of India, notably in Karnataka. Studies on the distribution of trace-elements in the komatiites of India are very few. This paper proposes a simple, accurate, precise, rapid, and non-destructive wavelength-dispersive x-ray fluorescence (WDXRF) spectrometric technique for determining Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th in komatiites, and discusses the accuracy, precision, limits of detection, x-ray spectral-line interferences, inter-element effects, speed, advantages, and limitations of the technique. The accuracy of the technique is excellent (within 3%) for Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Zr, Nb, Ba, Pb, and Th and very good (within 4%) for Y. The precision is also excellent (within 3%) for Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th. The limits of detection are: 1 ppm for Sc and V; 2 ppm for Cr, Co, and Ni; 3 ppm for Cu, Zn, Rb, and Sr; 4 ppm for Y and Zr; 6 ppm for Nb; 10 ppm for Ba; 13 ppm for Pb; and 14 ppm for Th. The time taken for determining Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th in a batch of 24 samples of komatiites, for a replication of four analyses per sample, by one operator, using a manual WDXRF spectrometer, is only 60 hours. 相似文献
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E. M. Prasolov S. A. Sergeev B. V. Belyatsky E. S. Bogomolov K. A. Gruzdov I. N. Kapitonov R. Sh. Krymsky V. O. Khalenev 《Geochemistry International》2018,56(1):46-64
This paper reports the first results of a study of 11 isotope systems (3He/4He, 40Ar/36Ar, 34S/32S, 65Cu/63Cu, 62Ni/60Ni, 87Sr/86Sr, 143Nd/144Nd, 206–208Pb/204Pb, Hf–Nd, U–Pb, and Re–Os) in the rocks and ores of the Cu–Ni–PGE deposits of the Norilsk ore district. Almost all the results were obtained at the Center of Isotopic Research of the Karpinskii All-Russia Research Institute of Geology. The use of a number of independent genetic isotopic signatures and comprehensive isotopic knowledge provided a methodic basis for the interpretation of approximately 5000 isotopic analyses of various elements. The presence of materials from two sources, crust and mantle, was detected in the composition of the rocks and ores. The contribution of the crustal source is especially significant in the paleofluids (gas–liquid microinclusions) of the ore-forming medium. Crustal solutions were probably a transport medium during ore formation. Air argon is dominant in the ores, which indicates a connection between the paleofluids and the atmosphere. This suggests intense groundwater circulation during the crystallization of ore minerals. The age of the rocks and ores of the Norilsk deposits was determined. The stage of orebody formation is restricted to a narrow age interval of 250 ± 10 Ma. An isotopic criterion was proposed for the ore-bearing potential of mafic intrusions in the Norilsk–Taimyr region. It includes several interrelated isotopic ratios of various elements: He, Ar, S, and others. 相似文献
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奥地利安东帕有限公司 《岩矿测试》2009,28(3):306-306
最新的流行病学研究表明,空气中较高浓度的悬浮细颗粒可能对人类的健康有不利的影响。根据该项研究显示,由于心脏病、慢性呼吸问题和肺功能指标恶化而导致死亡率的升高与细尘粒子有关。这些研究结果已经促使欧盟于1999年4月出台了限制空气中二氧化硫、二氧化氮、氧化氮、铅和颗粒物含量的法案(1999/30/EC),对各项指标包括对可吸入PM10颗粒的浓度提出了新的限制性指标。PM10颗粒是指可以通过预分级器分离采集的气体动力学直径小于10μm的细颗粒。目前研究的兴趣重点逐步偏向PM2.5这些更细微颗粒物,PM2.5这种颗粒物对健康有明显的不利影响。在欧盟指令2008/50/EC中,对PM10和PM2.5都提 相似文献
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Mining induced subsidence can significantly affect mining costs where major surface facilities and natural environment need to be protected. Overburden grout injection is a technology used to control coal mine subsidence by injecting the mine waste material extracted from the coal back into the inter-burden rock during longwall mining. The flowing slurry is here categorised as a nonlinear viscous cohesive (Bingham plastic) fluid. During longwall mining the grout slurry is pumped into the separated beds of the rock mass through a central vertical borehole, which is drilled deep into the inter-burden rock strata above the coal seam. However, a blockage can occur in the injection system when the slurry velocity falls below a certain critical threshold velocity, indicating a material phase change from cohesive-viscous to cohesive-frictional. In situ field injection tests through boreholes have been simulated at a smaller scale at the CSIRO laboratory in Brisbane by pumping the slurry through a radial disk (gap = 4 mm) from its centre. Laboratory experiments indicate a general, nonlinear, cohesive, viscous, frictional model for shear behaviour of the slurry, in which the material shear parameters are functions of the disk radial distance. Complete dimensional and dimensionless analytical solutions have been developed based on an approach related to Bingham–Herschel–Bulkley fluid mechanics. The derived formulae include relations for minimum pump pressure, local pressure and pressure gradient, wall shear stress, volume rate, velocity and velocity gradient. The theoretical results match the experimental measurements. The experiments covered slurries with maximum particle sizes of 0.5 to 2 mm with about 50% being larger than 100 µm. The viscosities at the various solids concentrations were measured with a standard torsion viscometer. This study differs from the previous research in several distinct aspects, namely, consideration of the variable shear parameters rather than fixed values, inclusion of total nonlinear behaviour, and implementation of a friction function to mimic behaviour of the deposited and consolidating stiff slurry, which can cause a significant pressure rise as a result of the increased shear resistance. 相似文献
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Alexander E. C. Broberg J. S. Kehren A. R. Graziani M. M. Turri W. L. 《Environmental Geology》1993,22(4):353-361
Bellechester, Minnesota, is a small community of approximately 155 residents located on the county line between Goodhue and Wabasha counties in southeast Minnesota's karst region. Bellechester is served by a 21-year-old wastewater treatment facility (WWTF) consisting of three waste-stabilization ponds. On 28 April 1992 six sinkholes were discovered to have drained cell 2 of the WWTF resulting in the loss of approximately 8.7×106 1 of partially treated effluent and about 600 m3 of soil into previously undetected subsurface voids of unknown dimensions. In the week following the collapse, approximately 200 water wells located within a 5-km radius of the WWTF were sampled in an after-the-fact, emergency sampling program. Twelve samples with elevated fecal coliform levels, 18 samples with nitrate-nitrogen greater than the 10 mg/1 standard, and no samples with elevated chlorides were found. However, the elevated levels could not be unambiguously attributed to the WWTF collapse. This is the third WWTF to fail by sinkhole collapse in southeast Minnesota since 1974. All three collapsed lagoons have been located in similar geomorphic and stratigraphic settings. However, at least two lagoons have collapsed in the adjacent area in northeast Iowa, and these lagoons are located at different stratigraphic positions. Twenty-two WWTFs constructed in southeast Minnesota's karst region in the last 25 years have been identified as subject to potential sinkhole collapse. An unknown but significant number of manure storage lagoons, flood control structures, etc., have also been constructed in the karst region and are at risk. Public agencies are beginning to develop plans to deal with the risk associated with existing and future waste lagoons in this environment. The critical hydrogeologic parameters that can be used to prioritize the risk of collapse at existing facilities include: (1) the lithology of the first bedrock beneath each lagoon, (2) the thickness of surficial materials between the lagoon and the bedrock surface, (3) the presence and construction of liners (seepage rate), and (4) the proximity to existing sinkholes. 相似文献
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岩石密度和超高压岩石折返速率 总被引：1，自引：3，他引：1
在常温常压条件下对中国大陆科学钻CCSD主孔100-3000米岩心样品进行了密度测量,建立了密度连续剖面,并界定了不同超高压岩石的密度值。通过对比高温高压物性实验资料,岩石密度随着退变程度增强而降低,榴辉岩密度变化序列为3.52g/cm3→3.49g/cm3→3.07g/cm3→2.93g/cm3。超高压长英质岩石密度变化序列为3.00g/cm→2.80g/cm3→2.65g/cm3。上述实验资料是讨论不同折返阶段岩石所受浮力的基础,为研究折返速率大小提供了基本参数。本文通过折返板块运动平衡时,上浮力与粘滞力平衡这一关系式,定量研究了大陆俯冲板块的折返速率,认为密度差产生上浮力从而引起折返,温度对板块折返速率的影响最为显著;密度差大小、折返角度、折返板块大小对折返速率也有直接的影响。定量模拟分析表明,在温度高于850℃时,板块的折返速率可以超过100mm/a;当温度降至700℃时,折返速率则低于1.5mm/a。作者认为在折返早期,温度较高,板块快速折返至60-70km榴辉岩相深度;随着传导散热,温度降低,板块以较慢的速率折返至中下地壳。折返速率的估算表明,浮力是板块折返第一阶段(从>100km深部折返至<40km的中下地壳)的主要驱动力。 相似文献
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滇东南锡、银、铅、锌多金属矿床主要分布在个旧、白牛厂、都龙3个矿区,而滇东南较大的3个花岗岩体又分别出露在3个矿区或附近.花岗岩体均形成于燕山晚期,岩石化学、矿物成分相似,富含锡、银、铅、锌、钨、铜等成矿元素.矿床主金属元素组合与岩体之间的距离由远而近出现由锡、钨、(铍、铌、钽)→锡、钨、(铁)、铜、铟→锡、铅、锌、银、铟、(锑)有规律的变化.花岗岩浆是成矿物质来源和成矿热源.岩浆侵入初期使上覆地层隆起产生背斜(凹陷部位成向斜);同时使地层产生一系列裂隙、压性断层或层间断裂;岩浆侵入晚期,这些断层再次活动,表现为张性,岩浆产生的含矿热液沿由其活动所造成的断裂迁移、充填、交代、沉淀而形成矿床. 相似文献