共查询到17条相似文献，搜索用时 203 毫秒
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河流与地下水的脱节现象广泛存在于干旱及半干旱地区,二者间的相互作用已成为目前的研究热点。在简要分析河流与地下水关系的基础上,综述了河流与含水层之间由饱和连接,经过渡脱节,演化为完全脱节系统的物理过程及机理和脱节系统形成的必要条件。总结分析了最大渗漏量法、临界地下水位法、水位波动法等河流与地下水关系判别方法以及优缺点。讨论了非稳定演化过程中河水的入渗规律以及介质时空非均质性对脱节系统的影响。分析认为目前脱节形成机理仍不完全明晰;简便有效的判别方法还需进一步研究;介质时空非均质性对河水渗漏的影响是未来研究的重要方向。 相似文献
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本文应用竖管测定法对黄河中游龙门—潼关段的河床沉积物的渗透性进行了试验研究,测得了黄河河床沉积物的垂向渗透系数和水平渗透系数;应用地下水模拟软件,研究了河水与地下水的相互作用,为研究黄河水与地下水相互关系奠定了基础。 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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弱透水层饱和粘性土中水分渗透规律研究 总被引：1，自引：0，他引：1
本文利用渗压仪,对弱透水层一饱和粘性土类的原状土样,进行不同水头差作用下的渗透试验,获得水在弱透水层不同孔隙类型中的渗透规律:V—I关系曲线及V—I关系方程等,为地下水资源评价提供了理论依据,具有重要的理论与实际意义。 相似文献
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河床沉积物的渗透系数是水文地质关键参数之一,其大小直接影响河水与地下水之间的转换关系。采用水头下降竖管试验法对滦河下游3个不同断面,共32个测试点河床垂向渗透系数Kv进行研究。结果表明:滦河床沉积物Kv值总体在0.17~2.93m/d之间变化,近似服从正态分布;沿不同地貌单元(冲积平原-海积平原-入海口)、不同河床断面以及在较小的1m×1m范围内沉积物Kv值均存在明显差异,变异程度由冲积平原向入海口处递增,表明河床沉积物的渗透性在空间上具有较强的变异性;河床两岸沉积物的Kv值明显小于河流中心,而在较短的流程内Kv值沿河流流线方向基本不变。颗粒分析结果显示沉积物颗粒的大小与分布是造成渗透系数差异性的主要原因。此外,河床中的淤泥质层会极大地降低沉积物的渗透能力,减弱河水与地下水之间的水量交换能力。研究结果对滦河流域河水和地下水转换关系研究提供了理论和数据支持。 相似文献
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在傍河水源地地下水资源评价中，如何确定河流的补给量是最重要的问题之一，本文利用室内试验，探讨了河流渗漏补给量与排泄水位，介质渗透性的关系，分析了在河流与地下水脱节前后，地下水位随河水位，排泄水位而变化的规律，建立了河流补给地下水的非线性渗透模型。 相似文献
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污染河水中氨氮对浅层地下水的影响 总被引：14，自引：2，他引：12
氨氮是目前地表水和地下水的一个重要污染源.室内试验选用3种天然砂土作为渗透介质, 以生活污水模拟污染河水, 经过近1 0个月的土柱试验, 发现氨氮在粗砂中第1 7天达吸附饱和, 第1 8— 1 4 0天去除率小于1 0 %, 在中砂中第1 30—1 4 0天吸附饱和, 以后均发生解吸出水浓度大于进水浓度.野外实验凉水河的氨氮浓度为4 6.86mg/L和2 6.95mg/L时, 地下水的氨氮浓度均小于1.1 0mg/L, 表明凉水河对地下水的实际影响不如室内大, 原因是底泥、河床下部渗透介质的厚度和岩性以及河水渗漏量的影响.排污河还清试验表明, 排污河清淤、灌入清水后, 会很明显地把排污河下部渗透介质中的氨氮带到地下水中, 造成地下水的二次污染. 相似文献
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Gennaro A. Stefania Marco Rotiroti Letizia Fumagalli Fulvio Simonetto Pietro Capodaglio Chiara Zanotti Tullia Bonomi 《Hydrogeology Journal》2018,26(1):147-162
A groundwater flow model of the Alpine valley aquifer in the Aosta Plain (NW Italy) showed that well pumping can induce river streamflow depletions as a function of well location. Analysis of the water budget showed that ～80% of the water pumped during 2 years by a selected well in the downstream area comes from the baseflow of the main river discharge. Alluvial aquifers hosted in Alpine valleys fall within a particular hydrogeological context where groundwater/surface-water relationships change from upstream to downstream as well as seasonally. A transient groundwater model using MODFLOW2005 and the Streamflow-Routing (SFR2) Package is here presented, aimed at investigating water exchanges between the main regional river (Dora Baltea River, a left-hand tributary of the Po River), its tributaries and the underlying shallow aquifer, which is affected by seasonal oscillations. The three-dimensional distribution of the hydraulic conductivity of the aquifer was obtained by means of a specific coding system within the database TANGRAM. Both head and flux targets were used to perform the model calibration using PEST. Results showed that the fluctuations of the water table play an important role in groundwater/surface-water interconnections. In upstream areas, groundwater is recharged by water leaking through the riverbed and the well abstraction component of the water budget changes as a function of the hydraulic conditions of the aquifer. In downstream areas, groundwater is drained by the river and most of the water pumped by wells comes from the base flow component of the river discharge. 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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河流与地下水关系的演化及若干科学问题 总被引：7，自引：1，他引：6
河流和地下水之间存在着密切的水力联系和频繁的转化关系。近几十年来,受自然因素和人类活动的影响,河流与地下水之间的转化关系趋于复杂化,引起水循环的变化,诱发了一系列生态环境负效益,使水资源及生态问题突显,其中河流与地下水关系及其演化是河流与地下水相互作用中重要问题之一,是属于河流维持机理与地下水可再生能力的基础研究内容。笔者在对河流与地下水转化关系类型划分的基础上,依据室内和野外试验资料,结合地质、水文地质条件,分析了各类型的渗流特征和影响河流与地下水关系演化的因素;从国内外研究现状出发,分析了当前该领域存在的不足和急待解决的有关科学问题,为定量模拟和评价河流与地下水的演化关系提供了科学依据。 相似文献
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The Mahoning River is one of the five most contaminated rivers in the U.S. This study characterized the contaminated sediments in the river banks and investigated the hydraulic interconnection between shallow aquifer in the banks with the river water. The study was conducted along the most polluted section of the river, which is 50-km long, using over 50 monitoring wells. The characterization part of the study investigated the sedimentology, hydraulic conductivity, and spatial distribution of the contaminated sediments. Results of the characterization revealed that the contaminated sediments consist of fine-grained sand, silt, mud, and clay. The spatial distribution of the contaminated sediment is heterogeneous and positively correlates with the hydraulic conductivity values, i.e., the greatest contamination occurs in high conductivity areas. Hydraulic conductivity was determined by the Hazen formula using 82 sediment samples. Bioremediation, which is one of the remedial options considered for the banks, is found to be hydraulically feasible because of sufficient hydraulic conductivity values (≥10?4 cm/s) that ensure reasonable rates of nutrient delivery. Monitoring of water levels in the river and groundwater for a 10-month period shows that flow occurs from the river to groundwater and vice versa. The exchange of flow is influenced by rainfall. Flow of groundwater to the river will continually transport the dissolved contaminants in groundwater to the river. Therefore, findings of this study show that one of the remedial options that proposes dredging of channel sediments and permits no action for bank sediments cannot be chosen due to river water–groundwater interactions. 相似文献
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为提高地下水与地表水交换量计算结果的准确性,本文利用水力联系、水头差、水温、氡-222、氢氧稳定同位素构建综合识别方法（HHTRO）,对新汴河宿州段地下水与地表水水量交换进行识别,并计算交换量。计算结果表明:研究河段单位河长地表水补给地下水的水量变化范围为8.69~366.82 m3/（d·m）,地下水补给地表水的水量变化范围为0.72~120.90 m3/（d·m）;研究河段左岸为地下水补给地表水,单位河长净补给量为45.26 m3/（d·m）;河段右岸为地表水补给地下水,单位河长净补给量为214.33 m3/（d·m）;研究河段地下水与地表水水量交换以地表水补给地下水为主,地表水补给地下水的比例为55.14%。本研究可推动地下水与地表水交换量计算方法的发展,为流域或区域水资源评价提供必要的理论方法。 相似文献
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Channel sediment and alluvial aquifer hydraulic properties exert a major control on river–groundwater interactions. Channels and floodplains are often asymmetrical, resulting in differences in sediment hydraulic properties across the river. Floodplain asymmetry is common along Coastal Plain rivers in South Carolina and North Carolina, USA. The Tar River, North Carolina, has an asymmetrical valley. The study objective was to characterize the effects of floodplain asymmetry and geological controls on river–groundwater interactions. Floodplain and river channel sediments adjacent to the river were characterized with split spoon cores and hand auger samples along a 22-km reach. Hydrogeology was characterized with 38 piezometers and water level recorders in and adjacent to the river. Ground penetrating radar was used to define the shallow stratigraphy. Channel sediments were significantly different between the north and south sides of the river. Hydraulic conductivity and groundwater inputs were greater on the side of the river (north) that contained more permeable fluvial deposits. Groundwater chemistry (δ18O, specific conductance) data also suggested greater exchange between surface water and groundwater on the north side of the river channel. A conceptual hydrogeological model illustrates that groundwater movement and contaminant transport to the river differs across the channel due to asymmetrical geology. 相似文献
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David J. Allen W. George Darling Daren C. Gooddy Daniel J. Lapworth Andrew J. Newell Ann T. Williams Debbie Allen Corinna Abesser 《Hydrogeology Journal》2010,18(5):1125-1141
Understanding the processes controlling groundwater/surface-water interaction is essential for effective resource management and for protecting sensitive ecosystems. Through intensive monitoring of Chalk groundwater, shallow gravel groundwater and surface water in the River Lambourn, UK, using a combination of hydrochemical and hydrophysical techniques, a complex pattern of interactions has been elucidated. The river is broadly in hydraulic contact with the streambed sediments and adjacent gravels and sands, but these deposits are mainly hydraulically separate from the underlying Chalk at the site. The hydraulic relationship between the river and underlying alluvium is variable, involving components of groundwater flow both parallel and transverse to the river and with both effluent and influent behaviour seen. While the gravel aquifer is significant in controlling groundwater/surface-water interaction, its importance as a route for flow down the catchment is likely to be modest compared with river discharge. The hydrological complexity revealed in a geological setting typical of lowland UK Chalk streams has implications both for investigation methods and for management such as in the setting of environmental objectives in the European Water Framework Directive. 相似文献