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1.
黑河流域山区植被带草地蒸散发试验研究 总被引：26，自引：6，他引：20
利用Penman-Monteith(PM)、 ASCE-Penman-Monteith(ASCE-PM)和Priestley-Taylor(PT)公式以及两个小型蒸渗仪SW10与N6的实际观测,计算了黑河流域山区试验草地2002年夏季的蒸散发. PM与PT方法验证了其中的一个小型蒸渗仪SW10的蒸散量, 也能验证小型蒸渗仪N6的蒸散量. 研究表明, 这种小型蒸渗仪在测算内陆河山区草地蒸散量的适用性比较强. 热量平衡要素计算结果表明, 山区草地的热量主要消耗于蒸散发. 相似文献
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四个概念性水文模型在黑河流域上游的应用与比较分析 总被引：3，自引：1，他引：2
首先结合新安江模型、TopModel、HBV模型和Sacramento模型机理,从模型结构的土层划分、土壤水分计算、蒸散发计算、产流区不均匀性的考虑、产流机制、下渗机制等多个方面进行了理论上的比较,然后选择黑河流域上游为研究区,结合模拟结果对这四个概念性水文模型在黑河上游山区流域应用情况,从土壤水分、蒸散发、径流过程和各径流组分四个方面进行了分析比较。结果显示,概念性水文模型对黑河干流上游山区径流模拟有较好的模拟效果,但是对土壤水分、蒸散发等水文过程只能描述其变化趋势,难以定量,同时,我们还可以得出在所用四个模型中,HBV模型在黑河干流上游山区出山口的径流拟合中有和其他3个模型相当的Nash-Sutcliffe效率系数,并且在枯水期的表现也好,适用性最好。 相似文献
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为深入探索气候变化背景下更为精确的潜在蒸散发计算方法, 在淮北平原五道沟水文水资源实验站开展了3组小型蒸渗仪试验, 通过结合平流运动动力项并引入地表净辐射修正参数, 基于能量平衡原理提出一种新的潜在蒸散发模型。结果表明: ① 3组蒸渗仪实测数据中, 2组不同加水方式下的草地覆被蒸散发相关性较好(R=0.95);②新的潜在蒸散发模型在有草地覆被的2组试验中模拟结果的纳什效率系数(ENS=0.85)和均方根误差(ERMS=0.83)均优于现有Penman系列等经验方法; ③模型更适用于有草地覆被条件下的蒸散发估算, 在淮北平原地区具有较强的适用性与优势。该模型能够提高区域潜在蒸散发模拟精度, 为流域水循环过程模拟及水资源利用提供科学参考。 相似文献
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黑河流域山区植被生态水文功能的研究 总被引：21，自引：5，他引：16
依据土壤-植被-大气系统的结构特性,从林冠层、苔藓-枯枝落叶层、土壤层剖面结构分析了黑河流域山区水源涵养林在水文过程中的作用.观测试验表明,林冠截留大气降水的32.7%,使到达林地的水分相对减少而养分增加,而林冠遮荫使林内土壤蒸发仅为林外草地的34.2%.苔藓-枯枝落叶层疏松多孔,最大持水量可达12.5mm水层深,加上表层较高的体积含水量和较小的水分变差系数,使其在涵蓄一部分大气降水的同时具有良好的保水性能.林地土壤具有良好的渗透性和涵蓄大气降水的能力,从而减少了地表径流量.森林的蒸散发使林区空气湿度高于周边地区17%,形成山区独特的森林小气候,从而进一步影响着山区的水文过程. 相似文献
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内陆河流域分布式日出山径流模型——以黑河干流山区流域为例 总被引：13，自引：1，他引：12
应用常规的气象水文数据并结合GIS,建立了一个适合西北干旱区内陆河山区流域的以日为步长的分布式径流模型,并对黑河干流山区出山径流进行了模拟计算和讨论。模型以子流域作为最小的产流、汇流单元,根据植被覆盖将各子流域分为裸地区、乔木区、牧草区和冰川区,并根据实际调查将土壤分为 3层,各分区单独进行水量平衡计算。产流过程以土壤储水能力和储水量表征,而储水能力和储水量等则由土壤的孔隙度、干密度和厚度等表征。入渗原理基于土壤储水率平衡原理,并考虑重力势的作用。实际蒸散发与蒸发力和土壤体积含水量的乘积成正比,不同的土壤和植被具有不同的调节参数。模拟结果表明,模拟效果较差的原因是区域日降水过程具有较大的随机性,难以用有限的站点合理计算区域日降水量。寻找一个合适的区域日降水量计算方法是目前少资料大型流域分布式水文模型模拟成功的关键。 相似文献
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黑河上游土地利用动态变化及影响因素的定量分析 总被引：9，自引：4，他引：5
由于特殊的自然地理属性和人类活动方式, 西北干旱区黑河上游的土地利用方式有别于中下游地区, 土地利用格局演变过程对全流域水资源和生态环境的影响巨大.以黑河上游为研究对象, 以1987年, 1999年和2010年的遥感影像为基础数据, 运用转移矩阵法和主成分分析等方法定量分析了林地、 草地、 耕地3种主要土地利用类型的动态变化过程, 揭示了其变化的动力机制.结果表明: 1)黑河上游土地利用变化阶段明显, 林地、 草地和耕地3种土地利用类型在1987-1999年和1999-2010年两个阶段转化显著, 林地持续减少, 草地先减少后增加, 耕地持续增加; 2)单一土地类型分布格局差异大, 林地呈东多西少, 北多南少的分布格局; 草地呈东多西少, 南多北少格局; 耕地集中分布于河谷和城镇居民点周围及山前地带; 3)人为因素是影响黑河上游土地利用动态变化的关键因素. 相似文献
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“蒸发悖论”在黑河流域的探讨 总被引：4，自引：2，他引：2
利用黑河流域12个气象站点1960-2010年的气象资料,运用FAO Penman-Monteith模型计算潜在蒸散量,采用旋转经验正交函数、Mann-Kendall检验等方法系统分析了过去51 a间潜在蒸散量及气温的变化趋势,重点对"蒸发悖论"在黑河流域的规律进行分析.结果表明:根据潜在蒸散量的旋转经验正交函数分区结果,黑河流域可以划分为4个子区."蒸发悖论"仅于1960-1993年存在于黑河流域河西走廊区(Ⅱ区、Ⅲ区);其它各区无"蒸发悖论".1994-2010年由于潜在蒸散量的显著上升,河西走廊区"蒸发悖论"消失.1993年是黑河流域潜在蒸散量变化趋势的一个转折点,1994-2010年黑河流域的潜在蒸散量表现为统计显著的上升趋势.风速的变化是影响黑河流域河西走廊区"蒸发悖论"出现和消失的重要因素. 相似文献
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下渗强度的计算是干旱半干旱地区超渗产流计算的关键环节。河北雨洪模型中的流域下渗强度计算公式由两部分组成,一部分为由张力引起的下渗强度,另一部分为由重力引起的下渗强度(稳定下渗能力)。计算以上两部分下渗强度时,公式所用的雨量有重复,致使总下渗强度普遍偏大,从而导致模型模拟的洪水过程的洪量及洪峰偏小。提出一个改进的流域下渗强度计算公式,计算张力引起的下渗时所用雨强为总雨强与稳定下渗能力的差值。利用改进前后的计算公式,分别对2mm/h到10mm/h雨强及0mm到140mm表层土湿条件下的下渗强度进行计算,并对结果进行对比分析。大阁流域的实例应用结果表明,改进后的下渗强度计算公式,对模拟洪水过程的洪量和洪峰流量的增加效果明显,增加值分别为实测值的14.14%和10.08%。 相似文献
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东濮凹陷北部沙三中亚段广泛发育盐岩和烃源岩,这两个看似不能共存的物质却在这里互层共生。该时期研究区沉积特征为多盐韵律与多层烃源岩互层共生、连续沉积,单个盐韵律厚度从几米到十几米,烃源岩有机质丰度高、类型好。平面上,两者在湖盆沉积沉降中心共生;垂向上,高有机质丰度、好干酪根类型与高盐度地层具有较好的对应关系。因而成为恢复古气候和古环境的重要研究对象。通过岩石学、古生物学以及Sr/Ba、B/Ga、(V+Ni+Mn)、Fe/Mn、Sr/Cu、Mg/Ca、V/(V+Ni)、稀土元素含量和氯同位素等方法对凹陷北部沙三中亚段的沉积环境进行研究。结果表明,凹陷北部沙三中亚段为深水沉积的还原环境,古盐度较高,达到半咸水-咸水沉积;微量元素和孢粉化石特征表明研究区沙三中亚段为温暖潮湿的环境。 相似文献
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The Importance of the Precipitation and the Susceptibility of the Slopes for the Triggering of Landslides Along the Roads 总被引：3，自引：1，他引：2
Clemente Irigaray Francisco Lamas Rachid El Hamdouni Tomás Fernández José Chacón 《Natural Hazards》2000,21(1):65-81
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
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郯庐断裂南段研究进展与断裂性质讨论 总被引：13，自引：3，他引：13
据1：5万区域地质调查和专题研究资料，就郯庐断裂带是否南延与消失的原因，其与大别—苏鲁造山带交截形成的假位错效应，以及与中新生代沉积盆地形成演化的关系等作了新的阐述。在此基础上，讨论了郯庐断裂带是否为巨大的左行平移断层或转换断层。认为郯庐断裂带可能是在“古郯庐带”的基础上于早侏罗世重新活动、白垩纪强烈活动的地堑型枢纽断裂带。 相似文献
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Guboglo M. N. 《GeoJournal》1980,4(1):53-58
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
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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
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Jiayu Rong Michael Melchin S. Henry Williams Tatyana N. Koren Jacques Verniers 《《幕》》2008,31(3):315-318
The Global Stratotype Section and Point （GSSP） for the base of the Silurian System was defined in 1985. Since that time, a number of researchers have suggested that this section has serious deficiencies for use as a GSSP. As a result, in 2000, the Subcommission on Silurian Stratigraphy （SSS） proposed undertaking a formal restu@ of this GSSP, which was subsequently approved by the International Commission of Stratigraphy （ICS）. The result of this restudy was the formal proposal that the current GSSP, at 1.6 m above the base of the Birkhill Shale, at Dob＇s Linn, Scotland, should be maintained as the same locality and stratigraphic level, but the bios- tratigraphical definition of the boundary should be revised. The previously defined, basal Silurian grapto- lite zone, the Parakidograptus acuminatus Zone, should be subdivided into a lower Akidograptus ascensus Zone and a higher E acuminatus Zone. The base of the A. ascensus Zone, marked by the first appearance of A. ascensus, should be regarded as the biostratigraphic mark for the base of the Silurian. This proposal has now been formally approved by the SSS and ICS, and ratified by International Union of Geological Sciences. This is the first GSSP to undergo formal restudy and redefini- tion, and the proposal also included a recommended procedure for restudy of GSSPs. 相似文献
18.
Dean S. Oliver 《Mathematical Geology》1998,30(7):911-933
In reservoir characterization, the covariance is often used to describe the spatial correlation and variation in rock properties or the uncertainty in rock properties. The inverse of the covariance, on the other hand, is seldom discussed in geostatistics. In this paper, I show that the inverse is required for simulation and estimation of Gaussian random fields, and that it can be identified with the differential operator in regularized inverse theory. Unfortunately, because the covariance matrix for parameters in reservoir models can be extremely large, calculation of the inverse can be a problem. In this paper, I discuss four methods of calculating the inverse of the covariance, two of which are analytical, and two of which are purely numerical. By taking advantage of the assumed stationarity of the covariance, none of the methods require inversion of the full covariance matrix. 相似文献
19.
Deviation of the major axis of the inertia ellipsoid of the Moon from the direction toward the Earth
B. P. Kondratyev 《Astronomy Reports》2017,61(8):709-714
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
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正Artemia cysts are an extremely important component of aquaculture diets.It is well established that the cultivation of fish and shellfish derive substantial health and growth advantages when Artemia are included in the diets of the 相似文献