水文地质学-1-2电子教案.ppt

水文地质学-1-2,Preface,Groundwater is also called,undergroundwater,that is the water existing in the,pores of rocks and,soils,.The groundwater functions,include:resources,biological environment,disaster,geologic action and information,carrier,.Groundwater and its existing media are of other functions.Hydrogeologic actions in,national economy,are relative to groundwater and their functions of exiting media.,水文地质学,3.,水文地球化学,Hydrogeochemistry,1.,水文地质学基础,Sedimentary hydrogeology,4.,区域水文地质学,Regional Hydrogeology,5.,石油水文地质学,Petroleum,Hydrogeology,2.,地下水动力学,Groundwater dynamics,对于作为供水水源的地下水，必须评价其水质水量，查明其分布规律。这方面的工作形成了,供水水文地质学。,The quality and quantity of groundwater must be evaluated and its distribution must be investigated.These works form Hydrogeology for Water Supply,.,Preface,含有某些特殊组分，具有某些特殊性质，因而具有一定医疗与保健作用的地下水，称作矿水。矿水是建立矿泉疗养地与生产瓶装矿泉水的必要资源。勘查与评价工业矿水与医疗矿水，也形成了相应的学科分支,矿水水文地质学,Mineral Water Hydrogeology,。,Preface,第一章 地球上的水及其循环,Chapter 1 The water in,the earth and its cycle,第一章 地球上的水及其循环,1.1 The water in the earth,地球上的水,大气水,Meteoric water,地表水,Surface water,地下水,groundwater,1,2,自然界的水循环,Water cycle in nature,自大气圈到地幔的地球各个层圈中的水构成一个系统。这一系统内的水相互联系、相互转化的过程即是自然界的水循环。,The water in the spheres of the earth constitutes a system from atmosphere to mantle.The water in the system can interlink and inter-transform.The process is called water cycle in nature.,1.2,Water cycle in nature,自然界的水循环按其循环途径长短、循环速度的快慢以及涉及层圈的范围，可分为水文循环和地质循环两类。,The water cycle can be classified into two types:,hydrologic cycle and geologic cycle according to the cycle ways and cycle velocity and sphere scale.,1.2.1,水文循环,Hydrologic cycle,水文循环是发生于大气水、地表水和地壳岩石空隙中的地下水之间的水循环。水文循环的速度较快，途径较短，转换交替比较迅速。,1.2,Water cycle in nature,1.2.1,水文循环,Hydrocycle,水文循环分为小循环与大循环。海洋与大陆之间的水分交换为大循环。海洋或大陆内部的水分交换称为小循环。通过调节小循环条件，加强小循环的频率和强度，可以改善局部性的干旱气候。目前人力仍无法改变大循环条件。,Hydrologic cycle can be classified into small cycle and large cycle.,The moisture exchange between ocean and land is called large cycle.The moisture exchange in the ocean or on the land is called small cycle.The local dry climate can be improved by adjusting the conditions of small cycle and enhancing the frequency and strength.But now the conditions of large cycle cannot be changed.,地球浅层圈和深层圈之间水的相互转,化过程称为水的地质循环。,The interchanging process of water between shallow,sphere and deep sphere is called geologic cycle.,Chapter 1 The water in the earth and its cycle,1.2.1,地质循环,Geologic cycle,第一章 地球上的水及其循环,水文循环与地质循环是很不相同的自然界水循环。水文循环通常发生于地球浅层圈中，是,H20,分子态水的转换，通常更替较快。水文循环对地球的气候、水资源、生态环境等影响显著，与人类的生存环境有直接的密切联系。,第一章 地球上的水及其循环,水文循环与地质循环是很不相同的自然界水循环。水文循环通常发生于地球浅层圈中，是,H20,分子态水的转换，通常更替较快。水文循环对地球的气候、水资源、生态环境等影响显著，与人类的生存环境有直接的密切联系。,屈原,天问,柳宗元,天对,东穷归墟,又环西盈,脉穴土区,而浊浊清清,Chapter 1 The water in the earth and its cycle,水文循环与地质循环是很不相同的自然界水循环。水文循环通常发生于地球浅层圈中，通常更替较快。水文循环对地球的气候、水资源、生态环境等影响显著，与人类的生存环境有直接的密切联系。,Hydrologic cycle and geologic cycle are quite different water cycle.Hydrologic cycle usually produces in shallow sphere.Hydrologic cycle affects climate,water resources,bio-environment,heavily and is of close relation with,existing environment,of human being.,Chapter 1 The water in the earth and its cycle,水文循环,是水文学与水文地质学的研究重点。,地质循环,发生于地球浅层圈与深层圈之间，常伴有水分子的分解与合成，转换速度缓慢，过去常被人们所忽视。,Hydrologic cycle is the key point of hydrology and hydrogeology.Geologic cycle produces between shallow sphere and deep sphere,with,composition and decomposition,of water molecules and exchange slowly,and is always ignored.,Chapter 1 The water in the earth and its cycle,随着对各种成矿地质作用认识的深化，水参与各种地质作用过程的意义不断被人们所认识。研究水的地质循环，对于深入了解水的起源，水在各种地质作用过程乃至地球演化过程中的作用，都具有重要意义。,With the knowledge deepening of various,mineralization,the meaning of water participating in various geologic actions is recognized.Study on geologic cycle is of,significant,for researching the water role of various process of geologic action and the earth evolution.,(Geofluid),Chapter 1 The water in the earth and its cycle,1.3,与水文循环有关的气象、水文因素,1.3.1,气象因素,Climate factor,自然界中水循环的重要环节,蒸发、降水，都与大气的物理状态密切相关,;,气象和气候因素对水资源的形成与分布具有重要影响。,The key link of water cycle(evaporation and,precipitation,)are close relative with atmospheric physical state.Weather and climate are of significant for formation and distribution of water resources.,蒸发,在常温下水由液态变为气态进入大气的过程称为,蒸发,。空气中的水汽主要来自地表水、地下水、土壤和植物的蒸发。有了蒸发作用，水循环才得以不断进行。,Evaporation,In normal temperature water changes to vapor,the process is called evaporation.The vapor in the air is mainly from evaporation of surface water,groundwater,soil water and plant.Water cycle can carry out with evaporation.,Chapter 1 The water in the earth and its cycle,降水,当空气中水汽含量达饱和状态时，超过饱和限度的水汽便凝结，以液态或固态形式降落到地面，这就是降水。,Precipitation,When vapor content in the air reaches saturated,the vapor over saturated limit will be,condensed,and fall to ground in liquid or solid state.The process is called precipitation.,Chapter 1 The water in the earth and its cycle,径流,径流是水文循环的重要环节和水均衡的基本要素，系指降落到地表的降水在重力作用下沿地表或地下流动的水流。因此，径流可分为,地表径流和地下径流,，两者具有密切联系，并经常相互转化。,Runoff,Runoff is the important link of hydrologic cycle and the basic factor of water balance,which refers to flowing water along surface or ground under the gravity action.Therefore runoff can be classified into,surface runoff and ground runoff,.Both of them are of close relation and usually exchange each other.,Chapter 1 The water in the earth and its cycle,地表径流和地下径流,均有按系统分布的特点。汇注于某一干流的全部河流的总体构成一个地表径流系统，称为,水系,。,Surface runoff and ground runoff distribute in system.All the streams collect into a river and constitute a system of surface runoff,which is called a water system.,Chapter 1 The water in the earth and its cycle,一个水系的全部集水区域，称为该水系的,流域,。流域范围内的降水均通过各级支流汇注于干流。相邻两个流域之间地形最高点的连线即为,分水线,，又称,分水岭。,All the collecting area of a water system is called a,river basin,.The precipitation of the river basin is collected to,trunks,from its,branches.,The highest line is called,watershed.,Chapter 1 The water in the earth and its cycle,Spatial shape of the river,1.4 Outline of hydrocycle in our country,我国绝大部分地区均为,季风气候,，一年中,雨季,与,旱季,分明，降水的时空分布很有规律，这与我国特殊的地理格局有关。,Our country is mainly,monsoon,climate.The rain season and dry season are clear in a year.The space-time distribution of precipitation is regular,which is relative to special geographical location of our country.,Chapter 1 The water in the earth and its cycle,我国水文循环的另一重要特征就是降水在空间分布上的不均匀性。例如东南沿海地区年均降水量均在,1500mm,以上，最大可达2000,-,3000mm.,Another important feature of hydrologic cycle of our country is that the precipitation is not regular.For example,yearly precipitation in southeast area is over 1500mm,the maximum is 2000-3000mm.,Chapter 1 The water in the earth and its cycle,长江流域约,1200mm,，,华北地区一般在,600,-,800mm,；,而新疆塔里木盆地降水量仅在,50mm,以下，有的地方几乎终年无雨。这就导致水资源在空间分布上的不均匀性。,The precipitation in Yangtze river basin is above 1200mm,north China 600-800mm,but it is under 50mm in Tarim basin,Xinjiang.There is not almost any rain all the year in some places,which results in the irregular distribution of water resources.,Chapter 1 The water in the earth and its cycle,无论地表水或地下水，都是自然界水文循环中的一个环节，均以,大气降水为其补给来源,。因此，,一个地区水资源的丰富程度主要取决于降水量的多寡,。降水量大的地区，水资源较为丰富；反之，水资源贫乏。,(,焦作、贵州山区）,Whether surface water or groundwater are all a link of hydrologic cycle in nature.Their,recharge sources,are precipitation.Therefore the water resources in a district are mainly depend on precipitation.,Chapter 1 The water in the earth and its cycle,本章小结,自然界的水循环,水文循环（大循环、小循环）、地质循环,与水文循环有关的气象因素,气象因素：气温、气压、湿度、蒸发、降水,水文因素：径流（地表径流、地下径流）,我国水文循环：时空分布的不均衡,Chapter 1 The water in the earth and its cycle,第二章 岩石中的孔隙与水分,Chapter 2 Pores and moisture in rocks,Chapter 2 Pore and moisture in rocks,2.1,岩石中的,空,隙,Pores in rocks,地壳表层,十余千米,范围内，都或多或少存在着空隙，特别是地下一、两千米以内，空隙分布较为普遍。这就为地下水的赋存提供了必要的空间条件。,地 下 水 的 运 动 条 件,空隙,Moving conditions of groundwater,pore,空隙类型,松散沉积物,中的,孔隙,pore,坚硬岩石,中的,裂隙,crevice,可溶性岩石中,的,溶隙,、溶穴,cave,空隙度,一定体积岩石中空隙体积所占的比例,以,n,表示空隙度，,V,P,表示空隙体积，,V,表示岩石体积，则,n=V,P,/V,。,Chapter 2 Pore and moisture in rocks,2,2,岩石中水的存在形式,结合水,薄膜水,毛细水,重力水,靠静电和分,子引力吸附,于岩土颗粒,表面，不受,重力影响,吸着水表面,厚度超过几,百个水分子,直径的薄层,状水,受表面张力,作用保存于,毛细管中的,水，易被植,物吸收,受重力影响,可自由流动。,是地下水的,主要赋存状,态和水源,Chapter 2 Pore and moisture in rocks,2.3,与水的储容及运移有关的岩石性质,Rock properties relative to water volume and migration,岩石空隙大小、多少、连通程度及其分布的均匀程度，都对其储容及运移有关。,Chapter 2 Pore and moisture in rocks,2.3.1,容水度,容水度是指岩石完全饱水时所能容纳的最大的水体积与岩石总体积的比值。可用小数或百分数表示。一般说来容水度在数值上与孔隙度,(,裂隙率、岩溶率,),相当。但是对于具有膨胀性的粘土，充水后体积扩大，容水度可大于孔隙度。,Chapter 2 Pore and moisture in rocks,2.3.2,含水量,Water content,含水量说明松散岩石实际保留水分的状况。,松散岩石孔隙中所含水的重量与干燥岩石重量的比值。,Chapter 2 Pore and moisture in rocks,2.3.3,给水度（,）,若地下水面下降，则下降范围内饱水岩石及相应的支持毛细水带中的水，将因重力作用而下移并部分地从原先赋存的空隙中释出。我们把地下水位下降一个单位深度，从地下水位延伸到地表面的单位水平面积岩石柱体，,在重力作用下,释出的水的体积，称为,给水度,。,Chapter 2 Pore and moisture in rocks,2.3.4,持水度,(Sr),如前所述，地下水位下降时，一部分水由于毛细力,(,以及分子力,),的作用而仍旧反抗重力保持于空隙中。地下水位下降一个单位深度，单位水平面积岩石柱体中反抗重力而保持于岩石空隙中的水量，称作,持水度,(Sr),。,Chapter 2 Pore and moisture in rocks,2,3,4,持水度,给水度、持水度与孔隙度的关系,+Sr=n,Chapter 2 Pore and moisture in rocks,2,3,5,透水性,Permeability,岩石的透水性是指岩石允许水透过的能力。表征岩石透水性的定量指标是渗透系数。关于渗透系数将在第四章专门讨论。在此仅讨论影响岩石透水性的因素。,Rock permeability refers to the ability of water penetration.The permeable quantitative index is permeable coefficient.,Chapter 2 Pore and moisture in rocks,图,2,-,9,表示圆管状孔隙通道的纵断面，孔隙的边缘上分布着在寻常条件下不运动的结合水，其余部分是重力水。由于附着于隙壁的结合水层对于重力水，以及重力水质点之间存在着摩擦阻力，最近边缘的重力水流速趋于零，中心部分流速最大。由此可得出：孔隙直径愈小，结合水所占据的无效空间愈大，实际渗流断面就愈小；同时，孔隙直径愈小，可能达到的最大流速愈小。因此孔隙直径愈小，透水性就愈差。当孔隙直径小于两倍结合水层厚度时就不透水。,如果我们把松散岩石中的全部 孔隙通道概化为一束相互平行的等径圆管,(,图,2,10),，则不难推知：当孔隙度一定而孔隙直径愈大，则圆管通道的数量愈少，但有效渗流断面愈大，透水能力就愈强；反之，孔隙直径愈小，透水能力就愈弱。由此可见，决定透水性好坏的主要因素是孔隙大小；只有在孔隙大小达到一定程度，孔隙度才对岩石的透水性起作用，孔隙度愈大，透水性愈好。,然而，实际的孔隙通道并不是直径均一的圆管，而是直径变化、断面形状复杂的管道系统,(,图,a),。岩石的透水能力并不取决于平均孔隙直径,(,图,2b),，而在很大程度上取决于最小的孔隙直径,(,图,c),。此外，实际的孔隙通道也不是直线的，而是曲折的,(,图a),。孔隙通道愈弯曲，水质点实际流程就愈长，克服摩擦阻力所消耗的能量就愈大。颗粒分选性，除了影响孔隙大小，还决定着孔隙通道沿程直径的变化和曲折性,(,图,2a),，因此，分选程度对透水性的影响，往往要超过孔隙度。,2.4,有效应力原理与松散岩土压密,2.4.1,有效应力原理,Effective stress principle,太沙基,(Terzaghi,，,1925),所提出的有效应力原理可以帮助我们分析地下水位变动情况下岩石有效应力的变化以及由此引起的松散岩石压密问题,Effective stress principle that Terzaghi(1925)put out can help us to analyze the change of rock effective stress under the conditions of groundwater level,fluctuation,and the problems of loosen rock compressed.,Chapter 2 Pore and moisture in rocks,总应力等于孔隙水压力及有效应力之和,P,u+Pz (2,2),Pz=P-u (2,3),有效应力等于总应力减去孔隙水压力，这就是著名的,太沙基有效应力原理,。,Chapter 2 Pore and moisture in rocks,2.4.2,地下水位变动引起的岩土压密,为了简便起见，我们假设整个含水砂层充满水，且水位下降后其测压管高度仍高出饱水砂层顶面。这种情况下，当由于抽水而引起测压管高度降低时，可近似地认为总应力,P,不变，孔隙水压力降低，相应地有效应力增加。意即原先由水承受的应力由于水头降低，浮托力减少而部分地转由砂层骨架,(,颗粒本身,),承担。,Chapter 2 Pore and moisture in rocks,砂层是通过颗粒的接触点承受应力的。孔隙水压力降低，有效应力增加，颗粒发生位移，排列更为紧密，颗粒的接触面积增加，孔隙度降低，砂层受到压密。与此同时，砂层中的水则因减压而有少量膨胀。,Chapter 2 Pore and moisture in rocks,砂层因孔隙水压力下降而压密，待孔隙水压力恢复后，砂层大体上仍能恢复原状。砂砾类岩土基本上呈弹性变形。但是，如果同样的压密发生于粘性土中，则由于粘性土释水压密时结构发生了不可逆转的变化，即使孔隙水压力复原，粘性土基本上仍保持其压密状态。粘性土以塑性变形为主。（含水量,80%5%,）,Chapter 2 Pore and moisture in rocks,抽水引起地下水位下降，松散岩石将被压密，从而其孔隙度、给水度、渗透系数等参数均将变小。对于粘性土来说，这种参数值的降低是不可逆的。,Pumping,groundwater produces water level drawdown,loosen rocks are compressed,so as to decrease porosity and penetration coefficient and so on.All of these are,irreversible,for,clay,Chapter 2 Pore and moisture in rocks,1 The effective stress principle and emission consolidation process,1.1 The effective stress principle,The total stress(P)of saturated soil equals to effective stress(Pz)and pore water pressure(),P=Pz,This is called,effective stress principle,.The effective stress is also called the pressure among particles,and is the stress to control compress and shearing strength.,Chapter 2 Pore and moisture in rocks,1.2 Emission consolidation process,There are three kinds of reasons for the compress of saturated soil:(1)the compress of soil particles;(2)the compress of porous fluid;(3)the emission porous fluid.Owing to the compress of soil particles and fluid are little,the compress of soil are primarily resulted from fluid emission and porous compress.Under the pressure some free water in the pore of saturated soil will be emitted continuously with time passing.,Chapter 2 Pore and moisture in rocks,At the same time,the porous volume subtract and pore water pressure()are transformed into effective stress(Pz)which are undergone by particles.The compression of saturated soil is called emission consolidation process.The process is that pore water pressure disappears continuously and effective stress increases under the control of effective stress.,Chapter 2 Pore and moisture in rocks,2,Development mechanisms of,overpressure,in mudstone,It is well-known that the mudstone in a sedimentary basin always develops overpressure especially in the thick mudstone in the center of the basin.Why does the mudstone develop overpressure?This can be explained by effective stress principle and emitting water consolidation theory.,Chapter 2 Pore and moisture in rocks,Chapter 2 Pore and moisture in rocks,sandstone,Section,mudstone section closing sandstone,mudstone,section,overpressure section,mudstone section,Chapter 2 Pore and moisture in rocks,一、选择题,在括号内的三项选择中选择一项最佳答案。,岩石的给水度通常（,a.,大于、,b.,等于、,c.,小于）它的空隙度。,Summary,空隙：孔隙、裂隙、溶隙,水的存在形式,结合水、薄膜水、毛细水、重力水,几个重要概念,容水度、含水量、给水度、持水度,Chapter 2 Pore and moisture in rocks,此课件下载可自行编辑修改，仅供参考！感谢您的支持，我们努力做得更好！谢谢,