渭河下游"03"洪水对河道冲淤及河势变化的影响

2003年汛期渭河下游出现了自1981年以来的较大洪水,成阳、临潼、华县洪峰流量分别为5340、5100、3570 m3/s,其洪峰水位达历史最高,洪水过程首尾相接,六次洪水过程造成干支流堤防决口11处,洪灾损失极其严重.着重分析了"03"洪水对渭河下游河道冲淤及河势变化带来的影响.     

渭河流域甘肃段洪水动态变化规律特征研究

渭河是黄河最重要的一条支流之一,研究和分析渭河多年径流变化特征,有助于把握渭河多年径流情势,更有助于对黄河多年径流情势的把握。近年以来的研究主要集中在渭河径流分析过程和对渭河洪水过程的研究。通过对渭河甘肃段6个水文站近14年洪水资料进行分析,重点从渭河洪水的历时、洪水总量和洪峰流量等方面出发,得出渭河洪水的发生和变化规律,结果可知:渭河流域一般干流上洪水总量大,洪水历时较长,容易造成洪涝灾害;而河道支流洪量通常较小,对沿岸的危害较小,其中葫芦河秦安站由于地势特别,洪水总量大,历时短,需要加大沿岸的防洪力度。研究结果对渭河未来洪水防治提供了理论依据。     

渭河下游南山支流综合治理及防洪对策分析

渭河下游南山支流治理区位于陕西关中东部,西起临渭区尤河,东至潼关县东桐峪河,北至渭河,南至秦岭北麓分水岭,是渭河水量的主要补给源之一。同时也是陕西省重点防洪地区之一。受河南省三门峡水库泥沙淤积影响,南山支流"南高、北仰、中间低凹",上游洪水暴涨暴落,下游泥沙淤积使堤防临背差达2~4 m,"小水大灾"频繁发生,已成为严重制约当地经济发展和社会稳定的重大问题。本文对渭河南山支流治理中支流堤防工程、华县南山支流入渭口防御渭河洪水倒灌工程和应急分洪工程三大防护工程进行介绍,提出应坚持防御洪水、控制洪水、利用洪水的防洪、减灾、兴利的综合性治河理念,充分发挥已建水利工程效益,实行多种工程措施和非工程手段并举,重视和加强非工程措施,深入研究工程体系及上游水库防洪调度规律,充分挖掘潜力,配套建设调度设施,形成长期有效的调度运用机制,确保渭河下游南山支流防洪安全,保障沿渭人民群众生命安全。     

泾河洪水特性分析

泾河是渭河最大支流,灾害性洪水频发。通过收集泾河历史洪水资料,采用水文学方法,统计、分类、归纳,分析泾河洪水特点及洪水形成、组合、演变规律。分析得出泾河洪水主要发生在7、8、9月,洪水过程有单峰和复式峰,一次洪水历时5~7天,泾河洪水年际变化不稳定,上游河段年际变化幅度大于下游河段。洪水主要由夏季暴雨水形成,来自泾河杨家坪、马莲河雨落坪以上区域,可分为干流型洪水、支流型和混合型洪水。     

1904年7月黄河上游及川西北洪水

1904年7月11日至18日(清光绪三十年五月二十八日至六月六日)在青藏高原东侧——青海东部、甘肃东南部、四川西北部等地,降了一次持续5～7天的大雨和暴雨,使黄河流域的黄河上游、渭河上游,长江流域的嘉陵江支流西汉水和白龙江、岷江及其支流大渡河和青衣江以及雅砻江等江河发生了一场近百年来罕见的大洪水。这场降雨的主要特点是:西部高原降水、雨区     

1933年8月黄河中游洪水

一、概述 1933年8月上旬,黄河中游河口镇至陕县间,发生了一次陕县站自有水文记录以来的最大洪水。造成该次洪水的暴雨,面积广,强度大,雨区呈西南东北向分布,西自渭河上游,东至汾河上游,雨区还波及到黄河上游的庄浪河、大夏河和清水河等支流。     

渭河下游支流石川河及赤水河水文站网布设浅析

渭河下游特别是三门峡库区范围是陕西省的重点防汛地区之一,左右两岸支流较多,水文站网布设不完善,代表性差,洪水情况及水资源总量不能及时准确掌握。通过对石川河和赤水河流域已有水文站网存在的问题进行具体分析,并对渭河南山支流石川河和赤水河从设立水文站点的必要性、可行性等方面进行了探析。     

渭河干流典型断面非点源污染监测与负荷估算

渭河水质在较大程度上受非点源污染的影响,因此,有必要对其负荷和比重进行研究。2009年至2010年,对渭河干流关中段咸阳和临潼断面进行了洪水期和非洪水期水质水量同步监测。根据监测结果及水文站实测流量资料,分别采用改进的水文分割法和平均浓度法对两断面的非点源污染负荷进行了计算,分析了非点源污染的特点。结果表明:渭河干流关中段主要污染物为COD、NH₃-N和TN,两断面洪水期间各指标的平均浓度基本都小于平时的平均浓度;各指标非洪水期浓度变化总体上小于洪水期浓度变化幅度,量级较大的洪水水质变化幅度相对较小;改进的水文分割法和已被检验并被广泛采用的平均浓度法计算结果符合良好。2009年(枯水年,P=68%)渭河咸阳和临潼站各指标非点源污染所占比例基本在20%～30%左右;2009年渭河干流咸阳-临潼河段污染以点源污染为主,构成比例在80%以上。对比2006年(枯水年,P=69%),2009年临潼站COD、NH₃-N和TN年点源负荷分别减少11937t、791t和29t,渭河点源治理取得一定成效;此外,临潼站这两年的污染构成比例基本相同。非点源污染在渭河水污染中占较大比重,其对渭河水质的影响不容忽视。     

温德河流域“2010·07”暴雨洪水分析

2010年7月27～28日,第二松花江支流温德河流域普降特大暴雨,致使温德河干流发生了350年一遇超历史纪录的特大洪水。依据实测资料和暴雨洪水调查成果,分析了此次暴雨洪水的特性,以及水利工程在抵御洪水中的作用,并与历史最大暴雨、最大洪水进行了对比分析,为该流域暴雨洪水灾害及防治对策研究积累了经验。     

北洛河“2021.10”秋汛暴雨洪水分析

受强冷空气和西太平洋副热带高压外围西南暖湿气流共同影响,2021年10月3-6日北洛河流域出现一场历史罕见的高水位、大灾情的洪水过程。本文从暴雨洪水特性及渭河干流洪水影响等方面对北洛河“2021.10”秋汛暴雨洪水与历史典型“94.8”暴雨洪水进行了对比分析。研究结果表明,与“94.8”暴雨洪水相比,“2021.10”暴雨洪水的暴雨过程历时长、强度小、覆盖面积大;洪水过程洪水总量大、传播时间长、下游洪水水位高,并针对高水位、大灾情的洪水提出了防御建议,为水灾害防御工作提供参考。     

Unity of the national and the international in the socio-cultural development of the peoples of the USSR

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.     

Report of the restudy of the defined global stratotype of the base of the Silurian System

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.     

Deviation of the major axis of the inertia ellipsoid of the Moon from the direction toward the Earth

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″.     

The Tendencies of the Development of the Mineral-Resources Sector at the Turn of the Century

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.     

Causes of the famine among the rural population of the Sahelian zone of the Sudan

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.     

东濮凹陷北部沙河街组三段中亚段沉积环境分析

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。     

郯庐断裂南段研究进展与断裂性质讨论

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。     

The Importance of the Precipitation and the Susceptibility of the Slopes for the Triggering of Landslides Along the Roads

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.