共查询到20条相似文献，搜索用时 78 毫秒
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在分析研究区地质及水文地质条件的基础上,根据对各类水样资料的研究,发现在洛河下游,对于相对惰性的组分,河水的化学成分由河水与地下水混合形成,并且从水化学的角度验证了在该区段补给河水的那部分地下水主要来自洛河以南的地下水;但对于易发生化学反应的组分,河水在向下游运动的过程中,其化学成分明显受到了化学反应的影响。论文使用Cl^-质量平衡方法,计算出洛河上游河水中地下水的补给比例在20～30％左右,下游地下水补给比例约占70％左右;并且根据研究区的具体条件及矿物饱和指数的计算结果,确定了石膏、方解石的溶解和白云石的沉淀以及碳酸平衡是河水化学成分形成的主要化学作用,通过对化学反应量的计算,恢复了河水与地下水仅发生了简单混合作用的混合水的成分。 相似文献
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在对研究区地质及水文地质条件进行分析的基础上,根据对各类水样水质资料的分析,得出与补给水相比,布隆湖水中各组分含量普遍升高、TDS显著增大、水化学类型由HCO3.Cl型变为Cl.SO4.HCO3型、水质由良好的饮用水变为多种组分含量超标的不可饮水;认为布隆湖水的化学成分是在补给水化学成分的基础上,经过蒸发浓缩作用、溶解/沉淀及阳离子交替吸附作用而形成的。使用离子比值分析方法,估算出河水进入布隆湖后,蒸发比例高达71.43%,使各组分含量增大了约3.5倍;质量平衡模拟结果表明,形成湖水化学成分的主要化学作用是岩盐、石膏的溶解、方解石的沉淀以及CO2的逸出,此外还发生了少量的阳离子交替吸附作用。 相似文献
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《地下水》2021,(3)
河南省永城市日月湖生态景区治理工程在给永城市人民带来一个优美生态环境的同时,治理区地形、微地貌、水文及水文地质等条件也发生了变化,尤其是开挖后浅层地下水直接出露地表形成湖水,其水质相比之前埋藏于地下会发生改变。论文在阐述永城市日月湖景区水文地质条件的基础上,重点分析了治理区湖水、河水和浅层地下水的水化学和氘氧同位素特征。分析结果表明,湖水的水化学类型为HCO_3-SO_4-Na(Mg)型;河水水化学类型以SO_4-HCO_3-Na型为主;浅层地下水的水化学类型为HCO_3-Na-Mg型或HCO_3-Mg-Na型,个别水样中Cl-含量较高,水化学类型为HCO_3-Cl-Na(Mg,Ca)。湖水和地下水的水化学类型更接近,说明浅层地下水是湖水的重要补给来源。河水的TDS最高,浅层地下水TDS其次,湖水的TDS相对最低。研究区不同水体的氘氧同位素的分析结果说明,湖水受蒸发作用影响同位素富集;河水氘氧同位素与降水和地下水比较接近,其补给来源为大气降水和地下水;地下水除接受大气降水补给及雨季受河水补给外,还接受区域较高处的侧向径流补给,既有近源补给,也有远源补给。 相似文献
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河水入渗路径和范围对确定地下水补给条件,以及水资源调控和合理利用有着重要意义。针对2015年以来怀柔地区地下水水位回升现象,开展了地下水动态影响因素研究,采集了河水和地下水样品,测试了水化学和氢氧稳定同位素组成。δD-δ18 O数据表明该区有河水入渗补给地下水,河流附近地下水为地下水与入渗河水的混合物。利用地下水δ18O值以及二元混合模型计算了地下水中入渗河水的比例,揭示出地下水中河水占比减小方向与地下水水力梯度下降方向一致;局部河段附近地下水Cl-含量增加,表明河水入渗会引起地下水水质变化。入渗河水影响范围的圈定为评价入渗河水对地下水的影响提供了重要数据。该项工作对理解研究区地下水水文过程、控制因素以及水资源管理具有指导意义。 相似文献
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开展河流和地下水转换关系研究对于区域水资源合理开发利用具有重要意义。文章以大西沟河水与地下水转换关系为目标,在分析地下水动力场的基础上,通过水化学类型、溶解性总固体(TDS)、氯离子（Cl-）等水化学以及环境同位素18O、D、T等指标作为示踪剂,分析大西沟河和地下水的转换关系和转化强度。结果表明:研究区河流和地下水化学类型主要为HCO3—Ca,水化学类型空间分布特征相似;TDS和Cl-浓度表现为先增加后下降,但地下水的变化幅度大于河水。通过对大西沟河水和地下水中的水化学和环境同位素指标对比分析,发现研究区河流与地下水之间补给排泄关系具有明显的分段性;从河流出山口到下游地区,河水和地下水之间发生了三次转化关系:在山前倾斜砾质平原区以河水入渗补给地下水为主,补给量占该段潜水径流量的56%;到了细土平原区出现地下水补给河水地段,补给源为承压水越流补给潜水后的混合水体,潜水和承压水补给比例占该段河水径流量的20.4%与58.4%;风成沙漠区河水沿途渗漏补给地下水直至河流断流。本次研究结果为建立研究区水循环演化模式和水资源合理开发利用提供了理论和技术支持。 相似文献
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河水入渗补给是傍河水源地的主要补给来源,确定河水补给强度对于促进水源地长期安全的开采具有十分重要的意义。以沈阳黄家水源地为研究区,通过对比研究区河水、地下水的水化学及氢氧稳定同位素特征,分析了水源地地下水的补给来源及强度。结果表明:傍河水源地地下水主要接受河水的入渗补给和区域地下水的侧向补给;受河床沉积物和含水介质的岩性及结构在空间上的差异影响,河水入渗补给后在向地下水位漏斗中心流动的过程中具有浅层和深层两条地下水流路径,深层地下水与河水的水力联系更为紧密;河水对地下水的补给强度具有明显的时空变化特点,表现为雨季河水入渗强度明显大于旱季,并且随着与辽河距离的增加,水源地地下水获得的河水补给量呈逐渐减小的趋势。 相似文献
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高寒山区的地表水与地下水相互作用的定量研究对水资源的评价及管理等具有重要意义,而目前在高寒山区开展的地表水与地下水相互作用的定量研究相对较少.以黑河上游葫芦沟流域为研究区域,采用温度示踪方法对高寒山区河水与地下水的相互作用进行了研究,并对温度示踪方法在高寒山区的适用性进行了讨论.监测了研究区两个时段的地温、河水水位、地下水水位以及河床沉积物底部不同深度处的温度,并对温度系列数据进行定量分析,计算了不同位置处河水入渗流速.结果表明:研究区河水水位普遍高于地下水水位;河床底部温度在9月份整体低于7月;流速计算结果表明监测时段内主要为河水入渗补给地下水,入渗速率整体介于2×10-6~5×10-5 m/s.温度示踪法在高寒山区的适用性分析表明:在地下水受多途径补给时,温度示踪法仅指示河水对地下水的补给,而其他水源对地下水的补给还要通过同位素方法和数值模拟等其他手段进行计算.影响高寒山区河水对地下水补给的因素主要有:河水与地下水水位、河床沉积物的水力传导系数与热容. 相似文献
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入海河口中河水与海水的混合是海洋学中一个重要的界面过程,两者混合尺度和混合速率关系到河流携带物质的扩散范围和归宿,采用天然示踪剂224Ra和226Ra计算河水与海水的混合速率。2010年8月28日,采集了闽江河口区地下水样20个、河水样13个、河水与海水的混合水样12个,分别测量了每个水样的盐度、224Ra活度和226Ra活度。结果表明：地下水中224Ra、226Ra活度普遍高于河水;所有水体中的224Ra活度普遍都高于226Ra活度;河水遇到海水后,224Ra活度出现较大幅度的增加,而226Ra活度的增加并不明显。基于224Ra与226Ra半衰期的差异,在只有河水与海水发生涡流混合的情况下,计算获得河水与海水的混合速率为140.2~142.5 m/h。 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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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
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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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Important tendencies in development of the world mineral-resources sector at the beginning of the 21st century were an increase in production and consumption of mineral materials differentiated by types of metals and nonmetallic mineral raw materials, by countries and regions, as well as the concentration of the production of mineral raw materials in a small number of countries, and a reduction in industrial reserves of minerals in the world economy, even at the current stage of their extraction. These tendencies should be taken into account in working out a strategy for development of the Russian mineral raw-material base. 相似文献
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Fouad N. Ibrahim Dr. 《GeoJournal》1988,17(1):133-141
Taking the example of W Sudan, an analysis of the climatic incidents leading to the two recent famine disasters is made. On this natural background, the human side is investigated. Focus is directed towards the fragile economic structure of the famine-prone population groups. An early-warning system for famine in the Sahelian Zone is proposed taking grain production and storage, livestock development and the relationship between the prices of livestock and grain as major indicators. 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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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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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