内陆浅层咸水成因机制与演化规律研究
发布时间：2018-11-11 16:03
【摘要】：淡水资源的短缺已成为制约我国经济发展的一个瓶颈。华北平原浅层咸~微咸水资源丰富,分布较广,而且具有埋深浅、补给快、易开采等特点。咸水资源作为非常规水源也应该得到重视。为了更科学合理的开发利用内陆浅层咸水,对于其成因机制及演化规律的研究显得尤为重要。本文以内陆平原浅层咸~微咸水为研究对象,从地下水动力场和水化学场两个方面,研究了内陆浅层咸水的动态变化特征,并分析其成因机制,进而揭示其演化规律。本文以内陆黄泛区济阳县典型咸水区为例,在查阅国内外相关文献的基础上,采用野外调研、钻探的方法手段,查明了研究区地质、水文地质条件;在野外试验如抽水试验、注水试验、示踪试验等与室内咸淡水驱替试验相结合的基础上,研究了内陆浅层咸水形成的水动力影响机制;根据浅层咸水水化学组分及水化学类型分布规律,运用数理统计、Piper三线图和离子比例系数等方法,系统地分析了济阳浅层地下水水化学场时空分布规律;在此基础上,探讨了浅层咸水的形成与地下水循环径流过程中各种水岩作用的内在联系;最后利用水文地球化学模拟软件PHREEQC,选取研究区三个典型地下水渗流路径进行反向水文地球化学模拟,并对模拟结果分析探讨,揭示了浅层咸水成因机制及演化规律。本文通过上述分析研究,得出以下结论:(1)内陆黄泛平原区浅层咸水位于古河道之间的径流滞缓区,埋深浅,地下水动态为典型的“气象-蒸发型”,野外试验揭示了研究区水力坡度较小,约为0.17‰,径流条件差,地下水循环交替强度较差的特点,粘土矿物含量高,有利于盐分的积累。地下水矿化作用显著,这对内陆咸水体的形成起到决定性作用。(2)室内咸淡水驱替试验说明,渗流液的盐度和pH对含水介质的渗透性具有明显的影响。随着盐度增加和pH的减小,渗流场的渗透系数呈减小的趋势,pH=7.4时渗透系数突降。渗透性能降低,进一步削弱了地下水的径流条件,有利于盐分的聚集。这与咸淡水驱替过程中复杂的水文地球化学作用息息相关。不同尺度的室内试验还揭示了尺度效应对水化学组分的影响,溶质迁移具有迟后效应。(3)6050组野外监测数据表明,降水和地下径流对咸水体的水平扩散影响较小,内陆咸水水质动态相对稳定,总体上符合地下水溶质含量从补给区-径流区-排泄区越来越高,水化学类型越来越复杂的分布特征,并呈现出明显的分带性。(4)内陆浅层地下水水化学类型复杂多样,既有溶滤成因,也有大陆盐化成因。济阳咸水主要是大陆盐化成因咸水。介于1.0~2.0的γNa/γCl比值以及大于4的γSO4/γHCO3比值揭示了研究区水化学类型的形成与溶滤作用、蒸发浓缩作用具有紧密联系。(5)根据112组水质测试资料结果表明,济阳地区浅层地下水水化学类型分为42类。不同地下水流动系统的地下水水位动态和水质的差异性,及其径流循环条件的差异性,导致其经历的水文地球化学作用类型和程度不同,这是形成复杂水化学类型根本原因。随地下水迳流途径的加长,浅层地下水的TDS增高,高矿化的Cl·SO4-Mg·Na·Ca型和Cl·SO4-Na·Mg型浅层咸水,呈点状零星分布于内陆地区。(6)内陆咸水的形成与演化受水动力交替强度、溶滤作用、蒸发浓缩作用、离子交替吸附作用及水-岩作用的影响。水文地球化学反向模拟表明,内陆浅层咸水演化过程中,沿不同的地下水渗流路径,影响其水化学组分形成的主导水化学作用不同,但并不是单一的某种水文地球化学作用促成的。总之,内陆浅层咸水的演化在径流途径上具有分带性,同时受径流条件影响,内陆浅层咸水演化缓慢且漫长。综上,内陆浅层咸水水化学特征变化取决于地形、气象、沉积环境、水动力条件、水文地球化学作用等多种原因。气象、地层岩性、地下水径流途径与循环深度、水文地球化学作用共同控制内陆浅层盐化咸水的形成及演化。
[Abstract]:The shortage of fresh water resources has become a bottleneck to the economic development of our country. The shallow and salty water in the shallow plain of the North China Plain is rich in water resources, wide in distribution, and has the characteristics of deep buried depth, fast supply, easy exploitation and the like. The salt water resources should also be paid attention to as a non-conventional water source. For the more scientific and reasonable exploitation and utilization of the inland shallow water, the study of its genetic mechanism and its evolution law is particularly important. In this paper, the dynamic characteristics of the saline water in the inland plain are studied from two aspects of the ground water power field and the water chemistry field, and the genetic mechanism of the saline water in the inland plain is analyzed, and the evolution rule is also revealed. In this paper, the typical salt water area in Jiyang County, inland, is an example. Based on the review of the domestic and foreign literature, the field investigation and the method of drilling are used to find out the geological and hydrogeologic conditions of the study area. In the field test such as pumping test and water injection test, On the basis of the combination of the tracer test and the indoor salty fresh water flooding test, the water dynamic effect mechanism of the water formation in the inland shallow water is studied. According to the chemical composition of the shallow water and the distribution of the water chemistry type, the mathematical statistics, the Piper three-line graph and the ion proportion coefficient are used. The temporal and spatial distribution of the water chemistry field in the shallow groundwater in Jiyang is analyzed in a systematic way. On the basis of this, the internal relationship between the formation of the shallow water and the role of various water rocks in the course of the groundwater circulation is discussed, and the hydrogeochemical simulation software, PHREEQC, is used. In this paper, the reverse hydrogeochemical simulation of three typical groundwater flow paths in the study area is carried out, and the simulation results are analyzed and discussed, and the mechanism and the evolution rule of the shallow salt water are revealed. Based on the above-mentioned analysis, the following conclusions are drawn: (1) The shallow salt water in the inland yellow pan-plain area is located in the flow-off zone, the depth of burial and the groundwater dynamic are typical 鈥渕eteorological-evaporation type鈥，
本文编号：2325379
[Abstract]:The shortage of fresh water resources has become a bottleneck to the economic development of our country. The shallow and salty water in the shallow plain of the North China Plain is rich in water resources, wide in distribution, and has the characteristics of deep buried depth, fast supply, easy exploitation and the like. The salt water resources should also be paid attention to as a non-conventional water source. For the more scientific and reasonable exploitation and utilization of the inland shallow water, the study of its genetic mechanism and its evolution law is particularly important. In this paper, the dynamic characteristics of the saline water in the inland plain are studied from two aspects of the ground water power field and the water chemistry field, and the genetic mechanism of the saline water in the inland plain is analyzed, and the evolution rule is also revealed. In this paper, the typical salt water area in Jiyang County, inland, is an example. Based on the review of the domestic and foreign literature, the field investigation and the method of drilling are used to find out the geological and hydrogeologic conditions of the study area. In the field test such as pumping test and water injection test, On the basis of the combination of the tracer test and the indoor salty fresh water flooding test, the water dynamic effect mechanism of the water formation in the inland shallow water is studied. According to the chemical composition of the shallow water and the distribution of the water chemistry type, the mathematical statistics, the Piper three-line graph and the ion proportion coefficient are used. The temporal and spatial distribution of the water chemistry field in the shallow groundwater in Jiyang is analyzed in a systematic way. On the basis of this, the internal relationship between the formation of the shallow water and the role of various water rocks in the course of the groundwater circulation is discussed, and the hydrogeochemical simulation software, PHREEQC, is used. In this paper, the reverse hydrogeochemical simulation of three typical groundwater flow paths in the study area is carried out, and the simulation results are analyzed and discussed, and the mechanism and the evolution rule of the shallow salt water are revealed. Based on the above-mentioned analysis, the following conclusions are drawn: (1) The shallow salt water in the inland yellow pan-plain area is located in the flow-off zone, the depth of burial and the groundwater dynamic are typical 鈥渕eteorological-evaporation type鈥，
本文编号：2325379
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