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1.
地下水流数值模拟是高放废物处置库选址中水文地质评价的重要内容.水文地质概念模型是地下水流数值模拟的基础和前提.在北山预选区水文地质分析基础上,利用DEM数据生成了研究区地表水系,据此确定了模拟范围;借助GMS软件,建立了研究区三维水文地质结构模型;再通过边界条件、流场特征、地下水均衡项和水文地质参数的分析和描述,建立了北山地区水文地质概念模型. 相似文献
2.
Groundwater flow and the associated surface water flow are potential negative factors on underground tunnels. Early detection of environmental impacts on water resources is of significant importance to planning, design and construction of tunnel projects, as early detection can minimize accidents and project delays during construction. The groundwater modeling software package Groundwater Modeling System (GMS), which supports the groundwater numerical codes MODFLOW and FEMWATER, was utilized to determine the impact of tunneling excavation on the hydrogeological environment in a regional area around the tunnel and a local hot springs area, at the “Tseng-Wen Reservoir Transbasin Diversion Project”, in Taiwan. A hydrogeological conceptual model was first developed to simplify structures related to the site topography, geology and geological structure. The MODFLOW code was then applied to simulate groundwater flow pattern for the hydrogeological conceptual model in the tunnel area. The automated parameter estimation method was applied to calibrate groundwater level fluctuation and hydrogeological parameters in the region. Calibration of the model demonstrated that errors between simulated and monitored results are smaller than allowable errors. The study also observed that tunneling excavation caused groundwater to flow toward the tunnel. No obvious changes in the groundwater flow field due to tunnel construction were observed far away in the surrounding regions. Furthermore, the FEMWATER code for solving 3-D groundwater flow problems, in which hydrogeological characteristics are integrated into a geographic information system (GIS), is applied to evaluate the impact of tunnel construction on an adjacent hot spring. Simulation results indicated that the groundwater drawdown rate is less than the groundwater recharge rate, and the change to the groundwater table after tunnel construction was insignificant for the hot spring area. Finally, the groundwater flow obtained via the GMS indicated that the hydrogeological conceptual model can estimate the possible quantity of tunnel inflow and the impact of tunnel construction on the regional and local groundwater resources regime of the transbasin diversion project. 相似文献
3.
在分析大区域地下水流数值模型构建缘起的前提下,系统论述了近年来地下水流数值模拟在大区域地下水资源评价、水文地质参数确定、地面沉降、溶质运移、海水入侵、盐渍化、风险评估、地下水管理及地表水与地下水的联合开发利用等方面的国内外研究应用现状;归纳、总结了目前大区域地下水流数值模型在灵敏度分析、裂隙和岩溶介质中模型建立、基于地下水流数值模拟的溶质运移模型建立、地下水流数值模型构建所需工作量等理论和方法研究及实际建模过程中存在的一些问题;展望了今后大区域地下水流数值拟在研究范围、模拟技术与方法以及与其它模型耦合等方面的发展趋势。 相似文献
4.
Modelling groundwater over-extraction in the southern Jordan Valley with scarce data 总被引：1，自引：0，他引：1
To deal with the challenge of groundwater over-extraction in arid and semi-arid environments, it is necessary to establish management strategies based on the knowledge of hydrogeological conditions, which can be difficult in places where hydrogeological data are dispersed, scarce or present potential misinformation. Groundwater levels in the southern Jordan Valley (Jordan) have decreased drastically in the last three decades, caused by over-extraction of groundwater for irrigation purposes. This study presents a local, two-dimensional and transient numerical groundwater model, using MODFLOW, to characterise the groundwater system and the water balance in the southern Jordan Valley. Furthermore, scenarios are simulated regarding hydrological conditions and management options, like extension of arable land and closure of illegal wells, influencing the projection of groundwater extraction. A limited dataset, literature values, field surveys, and the ‘crop water-requirement method’ are combined to determine boundary conditions, aquifer parameters, and sources and sinks. The model results show good agreement between predicted and observed values; groundwater-level contours agree with the conceptual model and expected flow direction, and, in terms of water balance, flow volumes are in accordance with literature values. Average annual water consumption for irrigation is estimated to be 29 million m3 and simulation results show that a reduction of groundwater pumping by 40% could recover groundwater heads, reducing the water taken from storage. This study presents an example of how to develop a local numerical groundwater model to support management strategies under the condition of data scarcity. 相似文献
5.
构建合理的水文地质概念模型对于地下水数值模拟至关重要,概念模型如果确定不合理,整个数值模拟将毫无意义。通常水文地质调查可以大致确定水文地质概念模型,然而对于一些不易被发现的补给源,通过水文地质调查也无法确定。水化学和同位素特征对地下水的补给源及水流路径有很好的指示作用,可以根据这些信息对水文地质概念模型进行细化。文章通过对研究区地下水取样,分析地下水水化学和同位素特征,确定出研究区内不易识别的地下水补给源及顶层黏土-粉质黏土的透水性,最终细化了水文地质概念模型边界条件。这对于后期得到正确的地下水流和溶质运移模拟结果具有重要意义。 相似文献
6.
在分析水文地质条件的基础上,采用遥感技术准确确定了北京市平原区地下水系统边界,并建立了地下水系统概念模型。采用基于有限元原理的FEFLOW软件建立了相应的地下水数值模拟模型,以2000年到2003年连续4个枯水年的地下水位动态资料对模型进行了验证和识别。运用识别后的模型进行了现状地下水水均衡、各典型水文年的补给量和开采潜力分析,并提出了地下水合理开发利用对策。研究表明识别后的模型置信程度较高,反映了实际的水文地质条件;2000年至2003年地下水系统均衡分别为-7.73亿m3、-6.02亿m3、-5.95亿m3和-4.38亿m3,补给总量分别为16.98亿m3、18.68亿m3、18.75亿m3和20.32亿m3;多年平均地下水补给资源量为22.98亿m3。平谷和昌平地区地下水还有开采潜力,密怀顺平原和城近郊区地下水已过量开采。地下水的合理开发利用应致力于开源节流、地表水地下水联合调蓄和中水回用。 相似文献
7.
Gropius M. Dahabiyeh M. Al Hyari M. Brückner F. Lindenmaier F. Vassolo S. 《Hydrogeology Journal》2022,30(6):1769-1787
Jordan suffers from water scarcity and groundwater covers the majority of Jordan’s water supply. Therefore, there is an urgent need to manage this resource conscientiously. A regional numerical groundwater flow model, developed as part of a decision support system for the country of Jordan, allows for quantification of the overexploitation of groundwater resources and enables determination of the extent of unrecorded agricultural groundwater abstraction. Groundwater in Jordan is abstracted from three main aquifers partly separated by aquitards. With updated geological, structural, and hydrogeological data available in the country, a regional numerical groundwater flow model for the whole of Jordan and the southernmost part of Syria was developed using MODFLOW. It was first calibrated for a steady-state condition using data from the 1960s, when groundwater abstraction was negligible. After transient calibration using groundwater level measurements from all aquifers, model results reproduce the large groundwater-level declines experienced in the last decades, which have led to the drying out of numerous springs. They show a reversal of groundwater flow directions in some regions, due to over-abstraction, and demonstrate that documented abstractions are not sufficient to cause the observed groundwater-level decline. Only after considering irrigation water demand derived from remote sensing data, the model is able to simulate these declines. Illegal abstractions can be quantified and predictive scenarios show the potential impact of different management strategies on future groundwater resources.
相似文献8.
地下水流系统理论和数值模拟技术分别是水文地质学的基本理论和技术方法,含水岩组的概化是地下水流系统分析和地下水数值模拟的重要基础,直接影响着数值模拟和水流系统分析的精度和可信度.为提高含水岩组概化的精度和可信度,提出一种含水岩组概化的新方法,即累积导水系数法.依据岩层厚度与渗透系数乘积累积值随深度的变化,以及水文地质剖面岩性分布的整体特征,概化含水介质结构.以玛纳斯河流域为例,应用该方法概化流域内的岩性剖面,结合GMS软件中TINS模块构建水文地质结构模型.结果表明,应用该方法概化后的含水层结构具有较好的合理性和仿真性,建立的三维模型很好地显示了研究区含水介质的空间展布特征,为建立地下水流模型奠定了良好的基础. 相似文献
9.
大兴迭隆起隐伏岩溶水资源评价及开采方案预测 总被引：2，自引：2，他引：0
大兴迭隆起地区隐伏岩溶地下水是北京市的重要水源,为保障水源地能持续为大兴、通州地区提供优质的城镇生活用水,需对研究区岩溶地下水进行水资源评价和开采规划预测分析。利用数值模拟法,应用GMS模拟软件对研究区岩溶水系统进行地下水流数值模拟及水位变化预测。建立的岩溶水系统模型分为5层,模拟验证期为12年9个月。由模型评价的岩溶水系统补给资源量为14 425.74×10^4m3/a,可开采资源量为14 310.52×10^4m3/a,其中岩溶含水层可开采量为2 309.36×10^4m3/a。在模型识别验证后,分4种开采方案对水源地进行开采预测,通过对典型观测孔水位过程线拟合和研究区水均衡分析可知,按2020年之前维持现状开采,2020年后停采念坛水源地,2025年后全区按可开采量进行开采的开采方案最为合理,可分批逐次实现水源地的采补平衡。 相似文献
10.
山东淄博市地下水资源评价及其合理开发利用研究 总被引：12，自引：4，他引：8
本文采用有限单元法进行地下水资源评价以解决评价区供水面积大、精度要求高的矛盾。首先根据实际的开采量和长期观测孔的水位资料,校正数学模型,反求有关参数;然后给定开采方案进行未来水头的预测;最后研究地下水资源的合理开发利用问题。利用有限单元法进行水源地或单一含水层的地下水资源评价已被证明是先进的、有效的。本文是对水文地质条件非常复杂的大面积的区域,用有限单元法进行地下水资源评价的一种尝试,可供类似地区参考。 相似文献
11.
In order to simulate the recovery of groundwater funnels under the condition of reducing groundwater abstraction, hydrogeological conditions of recoverability construction of Shijiazhuang groundwater funnel were analyzed, and a numerical simulation method was used based on the change of various parameters. The results show that the groundwater flow model can accurately reflect groundwater hydrogeological characteristics, and can guarantee the reliability of groundwater restoration prediction. The research has set up four schemes for rural water-saving, planting structure adjustment, urban reducing abstraction and integrated method. The effect of four restoration schemes on the restoration of groundwater funnels was compared with water table variations of two observation well. Comparison results show that the level changes of plan Three and Four are different from the other two kinds of exploitation and the drop trend of water table in the funnel area is flat. So we can conclude that Plan Three and Four have significant effect on the groundwater funnel restoration of Shijiazhuang. 相似文献
12.
Development of a 3D groundwater model based on scarce data: the Wadi Kafrein catchment/Jordan 总被引：2，自引：2，他引：0
Yajie Wu Wenqing Wang Mathias Toll William Alkhoury Martin Sauter Olaf Kolditz 《Environmental Earth Sciences》2011,64(3):771-785
In this work, a 3D groundwater flow model integrating all important geological features of the hydrogeological system is developed
to investigate hydrological processes in the Wadi Kafrein area of Jordan. A large amount of available geological and hydrological
data is integrated to construct a 3D groundwater flow model for the Wadi Kafrein area. Using the newly developed mapping approach,
the translation of the highly detailed geological formations to an unstructured finite element grids, can be accomplished
with high precision. The existing data set for model calibration is scarce, which is a typical situation for many hydrogeological
case studies. At first, the steady state calibration of the groundwater model is carried out based on the observation wells.
Then, the time and space-dependent recharge from precipitation are applied at the top surface of the finite element model.
The transient simulation is conducted during the period of 1996–2008 considering the abstraction rates of the production wells
and discharge of the springs. The calculated water levels are close to the observed values. The difference is partly caused
by return flows from irrigation and the groundwater inflow from the adjacent aquifers which are not taken into consideration
so far. Since the Wadi Kafrein area is an important agricultural area in the semiarid region of the Lower Jordan Valley, the
model developed in this study can be regarded as a useful tool for analyzing the hydrological processes and improving groundwater
management practices elsewhere affected by similar geological and hydrogeological conditions. 相似文献
13.
在第二松花江傍河开采适宜性评价的基础上,根据研究区的地质和水文地质条件,建立了水文地质概念模型及相应的数学模型,建立了基于Visual MODFlow的地下水流数值模型;以地下水水位降深不大于含水砂层厚度的1/3为准则,通过使预测流场与允许降深条件下的流场尽量接近,给出了第二松花江干流傍河开采条件下的地下水允许开采量。结果表明:现状年条件下区域地下水资源开采强度较小,而傍河开采条件下各适宜区地下水开采潜力巨大,在多年平均降水保证率条件下,地下水允许开采量可达140×104 m3/d;适度规模傍河开采可引起地表水与地下水转化关系的变化,但不会对河流生态功能产生不利影响。 相似文献
14.
The impact of groundwater withdrawals on the interaction between multi-layered aquifers with different water qualities in the Viterbo geothermal area (central Italy) was studied. In this area, deep thermal waters are used to supply thermal spas and public pools. A shallow overlying aquifer carries cold and fresh water, used for irrigation and the local drinking-water supply. Starting with a conceptual hydrogeological model, two simplified numerical models were implemented: a steady-state flow model of the entire groundwater system, and a steady-state flow and heat transport model of a representative area, which included complex interactions between the aquifers. The impact of increased withdrawals associated with potential future development of the thermal aquifer must be considered in terms of the water temperature of the existing thermal sources. However, withdrawals from the shallow aquifer might also influence the discharge of thermal sources and quality of the water withdrawn from the shallow wells. The exploitation of the two aquifers is dependent on the hydraulic conductivity and thickness of the intervening aquitard, which maintains the delicate hydrogeological equilibrium. Effective methods to control this equilibrium include monitoring the vertical gradient between the two aquifers and the residual discharge of natural thermal springs. 相似文献
15.
This study examines the groundwater characteristics in the Silver Bell Mountains, Arizona, USA, using a numerical model. Groundwater modeling is developed to describe the flow pattern in the study area and subsequently explores the possible interaction with regional porphyry copper deposits. A conceptual model is developed for the study area and regional hydrogeological conditions are simulated using the finite-difference groundwater flow model, MODFLOW-2005. The model results show that groundwater flow in the Silver Bell Mountains is strongly influenced by topography and its velocity varies with depth. In addition, the numerical model supports the idea of a continuous sustained interaction between groundwater flow and porphyry copper deposits in the Silver Bell Mountains. This interaction may result in continuing leaching of trace elements from the ore deposit, an important implication for continuing supergene alteration and enrichment of the porphyry copper deposit. 相似文献
16.
为了揭示华北型煤田松散承压含水层水文地质参数及其对地下水流数值模拟的意义,以安徽淮北煤田宿南矿区祁东煤矿松散层承压第四含水层(简称“四含”)为研究示范,对多个影响因素综合分析,采用层次分析-模糊综合评价法,对研究区四含水文地质参数进行分区,合理确定各分区的水文地质参数,并用于采煤情景下地下水流动态数值模拟。数值模拟结果表明：祁东煤矿2008-2012年浅部煤层开采过程中四含地下水流场没有明显改变,但南北分区水头差逐年增大,地下水流向始终从南向北,而且在井田北部水力梯度逐渐减小,在井田南部水力梯度逐渐增大,南北区以倾角为60°~70°、断距为10~320 m的魏庙断层为分界线,基岩中大倾角与大落差断层的出现是引起上覆松散承压含水层水力梯度异常的根本原因。 相似文献
17.
煤系水矿化度是影响低煤阶煤层气生成、运移和成藏的重要因素之一。以新疆准噶尔盆地南缘地区为研究区,把研究区划分为8个水文地质单元,分析了研究区煤系水矿化度的分布特征及其对产甲烷菌生存的影响。以1 000 m埋深为例,估算了各个水文地质单元内煤系水的甲烷溶解度,据此分析评价了各水文地质单元溶解运移甲烷的能力。通过煤系水的矿化度分布、氯离子浓度和区域地质构造形态分析,综合判断区域内煤系水的大致流向。以准南地区硫磺沟水文地质单元为例,探讨了矿化度与煤层气富集成藏的关系。研究结果表明,研究区矿化度分布具有南北分带、东西分段的特征。后峡水文地质单元、玛纳斯河-呼图壁河水文地质单元的南部、硫磺沟水文地质单元的南端和阜康水文地质单元的西部地区矿化度有利于产甲烷菌的生存和产气。后峡水文地质单元溶解运移甲烷能力最强。地下水的流向大致由南向北,地表水的径流会使地下水流向发生偏转。指出了硫磺沟水文地质单元内高矿化度中心和低水位的汇水洼地是低煤阶煤层气富集成藏的地区。 相似文献
18.
19.
天津市地下水流-地面沉降耦合模型 总被引：6，自引：0，他引：6
天津市平原区地面沉降主要由地下水大量开采引起,影响范围广、危害大,已成为天津市主要的环境地质问题。分析了研究区的水文地质条件,结合地下水开发利用状况,将研究区概化为6个含水层组,地下水流考虑三维非稳定流,地面沉降选用一维固结压缩模型,运用地下水流模型Modflow 2005和地面沉降模拟模块 Sub,建立了天津市平原区地下水流-地面沉降数值耦合模型,模型面积为1.1×104 km2,利用1998-2008年地下水位等值线、过程线、地面沉降过程线等资料对模型进行了识别。模拟期的地下水均衡分析表明,在多年开采条件下,越流补给、压缩释水、侧向边界流入分别占深层含水层补给量的41.84％、32.15％和24.17％。将调试后的模型应用于南水北调实施后地下水控采条件下的地面沉降趋势预测,显示出停采或减少地下水的开采,有利于减缓地面沉降下降速度,且表现出开采层位越往下,地面沉降恢复难度越大的变化趋势。 相似文献
20.
地下水资源是北京供水系统的支柱,设立地下水水源地保护区,是保护水源地最大可能免受人类活动影响、保证水质安全的重要措施。论文以北京市某典型水源地为例,在收集相关水文地质勘查、长期动态观测、水源地开采现状、规划及周边污染源调查等成果资料的基础上,建立了地下水系统水文地质概念模型,模拟出地下水流场。通过质点追踪技术,计算水源地水力捕获带范围。综合考虑水源地周边地形、地物和潜在风险污染源等因素,确定了水源地保护区的范围。结果表明,数值模拟法能客观详细地刻画实际地下水含水层的结构与水文地质条件,划分结果可靠、准确,能为地下水管理部门提供有效合理的保护依据。 相似文献