深基坑降水地下水渗流三维数值模拟

长江中下游地区第四系松散沉积层深基坑降水一般采用非完整井,且由于深基坑周围连续挡水墙难以深入含水层底板,所以其地下水渗流场变化极其复杂,具有明显的三维非稳定渗流特征。以南京地铁中和村站—元通站区间隧道修复工程深基坑降水为例,基于深基坑降水三维渗流数值模拟的理论与方法,在概化出水文地质模型的基础上,建立了研究区深基坑降水三维渗流数学模型,模拟了在潜水含水层,微承压含水层复合存在、含水层最深底板埋深达56.01m、基坑周围连续挡水墙埋深为44至47m、抽水井井深达40m、抽水井过滤器埋深为26至38m,基坑内地下水位降至埋深达26.00m情况下的地下水复杂流动状态,并据此确定出了最优降水方案。     

新疆阿瓦提绿洲灌区约束供水条件下地下水开采模式

针对干旱内陆河绿洲灌区地下水位上升及塔里木河源流区限额供水的现实条件,本文以新疆阿瓦提绿洲灌区为研究区域,通过MODFLOW建立地下水流数值模型,模拟了现状及限额供水后的预测结果,并根据灌区的实际情况提出合理的地下水开采方案,以达到有效调控地下水位的目的。此方案下地下水开采量为1.14×108m3/a,并在全区范围内合理控制地下水位,为防治土壤盐碱化、减少无效蒸发和区域水资源的优化配置提供了有益参考。     

地下水资源管理研究

在研究区水文地质条件概化的基础上 ,建立水文地质概念模型和地下水流数值模拟模型 ,并对地下水位进行预报。针对地下水资源开发利用中存在的主要问题 ,在地下水流数值模拟模型基础上 ,建立地下水资源管理模型 ,为新乡市地下水资源科学管理提供决策方案     

开采条件下海河流域平原区浅层地下水数值模拟研究

本文利用地下水数值模拟系统(GMS),建立了能反映海河流域平原区地下水含水层结构及其水流特性的大区域水文地质概念模型和地下水流模型,重点研究了在无开采井条件下地下水开采强度时空分布的特征,模拟了平原区1965~2005年41年间的地下水流场及漏斗的演变过程,综合分析了海河流域平原区浅层含水层长期开采条件下地下水系统的演变过程以及地下水开采带来的影响。同时,对所建立的地下水数值模型就流场、漏斗变化以及水文地质参数等多方面进行了识别和验证。采用经过率定和验证的模型,预测分析了水资源配置制定的地下水限采方案,为南水北调实施后对海河流域地下水的修复作用以及其它可能的影响提供了可靠的分析手段和措施。     

马池口应急水源地开采对区域地下水位影响分析

通过建立地下水系统数值模型,选择地下水模型软件FEFLOW求解,对马池口应急备用水源地启动后,经历两个枯水年,一个平水年后,区域地下水位下降情况进行了预测,水位下降小于3m的面积为174.77km2,下降3～7m的面积为81.86km2,下降7～9m的面积为28.24km2,下降大于9m的面积为15.35km2,预测结果与地下水位监测数据基本吻合。     

大庆长垣西部地区地下水溶解性总固体与含水层电性特征数值模拟研究

为了研究大庆长垣西部地区第四系白土山组含水层、第三系泰康组含水层的溶解性总固体(TDS)与含水层的电性特征之间的关系,利用研究区的电阻率(Rt)和自然电位(SP)测井资料,通过数值模拟方法建立TDS与Rt、SP之间的关系模型。当第四系白土山组含水层Rt>46Ω.m时,第三系泰康组含水层Rt>45Ω.m时,该层水质可达到TDS<1000mg/L;当第四系白土山组含水层及第三系泰康组含水层静自然电位(SSP)>17mV时,该层水质可达到TDS<1000mg/L;利用建立好的模型对研究区实际井的第四系白土山组含水层及第三系泰康组含水层TDS进行预测,结果误差均小于10%,预测效果较好。研究结果为评价大庆长垣西部地区的地下水水质和圈定具体的布井方位提供了依据,提高了地下饮用水的开采效率。     

基于Visual MODFLOW地下水位预测研究

地基基础设计中,地下水是最活跃、复杂且难把握的因素。地下水受季节、环境影响较大,在建筑物的使用年限内地下水位是波动的,较大的地下水位变化可能引起地基失稳、基础破坏,从而预测地下水位、了解地下水位变化情况对地基基础设计、保障建筑物的使用安全是十分必要的。Visual MODFLOW是国际上较为成熟的地下水数值模拟软件,通过其建立数值模型,输入相关数据可对地下水位进行预测,为研究地下水位对地基基础的影响提供了重要的工具。     

松散承压含水层地区深基坑降水三维渗流与地面沉降耦合模型

以上海环球金融中心基坑降水为例,根据基坑降水过程中有效应力和孔隙水压力的转化关系,建立了基坑降水与地面沉降的耦合模型,并采用有限差分数值模拟方法,模拟了在多层含水层复合存在、含水层最深底板埋深达145 m、基坑周围挡水连续墙埋深达34 m、抽水井埋深达55 m、抽水井过滤器埋深为34～55 m,单井抽水量为1420 m3/d的8口抽水井联合降水情况下,基坑中心下伏第Ⅰ承压含水层上部降压段水位降至埋深26 m时的地下水复杂流动状态及其地面沉降特征。经后续工程验证,该结果正确、可靠,该理论用于模拟预测此类地区深基坑降水引起的地下水流场变化及其地面沉降具有较高的可信度。     

西南喀斯特小流域地下水数值模拟

本文以位于西南典型喀斯特地区的贵州普定后寨河流域为研究对象,采用等效连续导水介质体概化方法建立喀斯特流域地下水数值计算模型.运用MODFLOW中的排水沟渠子程序包以及河流子程序包,构建考虑地表河与地下河系统与含水层地下水流交换水动力过程模拟方法,分析后寨河流域地下水流运动特征,估算含水层补排水量.模型计算的地下水位动态...     

基于 GIS 的地下水位预测管理信息系统

为了使北京市区域浅层地下水动态规律的数值模拟研究及地下水远期最高水位的预测模型预测成果更好地为城市规划、工程建设服务,将GIS技术与地下水位预测的专业模型相结合,研制开发了地下水位预测管理信息系统,使抽象的地下水位预测工作变得生动、直观和全面,使地下水位预测管理工作走向智能化和科学化,从而全面提升地下水位预测和管理水平.     

Influence of the South-North Water Diversion Project and the mitigation projects on the water quality of Han River

Situated in the central part of China, the Han River Basin is undergoing rapid social and economic development with some human interventions to be made soon which will profoundly influence the water environment of the basin. The integrated MIKE 11 model system comprising of a rainfall-runoff model (NAM), a non-point load evaluation model (LOAD), a hydrodynamic model (MIKE 11 HD) and a water quality model (ECOLab) was applied to investigate the impact of the Middle Route of the South-North Water Diversion Project on the Han River and the effectiveness of the 2 proposed mitigation projects, the 22 wastewater treatment plants (WWTPs) and the Yangtze-Han Water Diversion Project. The study concludes that business as usual will lead to a continuing rapid deterioration of the water quality of the Han River. Implementation of the Middle Route of the South-North Water Diversion Project in 2010 will bring disastrous consequence in the form of the remarkably elevated pollution level and high risk of algae bloom in the middle and lower reaches. The proposed WWTPs will merely lower the pollution level in the reach by around 10%, while the Yangtze-Han Water Diversion Project can significantly improve the water quality in the downstream 200-km reach. The results reveal that serious water quality problem will emerge in the middle reach between Xiangfan and Qianjiang in the future. Implementation of the South-North Water Diversion Project (phase II) in 2030 will further exacerbate the problem. In order to effectively improve the water quality of the Han River, it is suggested that nutrient removal processes should be adopted in the proposed WWTPs, and the pollution load from the non-point sources, especially the load from the upstream Henan Province, should be effectively controlled.     

Groundwater Resources in the Lagan Valley Sandstone Aquifer, Northern Ireland

Beneath Belfast and the Lagan Valley lies Northern Ireland's most important aquifer, the Triassic Sherwood Sandstone. Up to 300 m in thickness and with a total abstraction of around 31 000 m³/d, it is a modest aquifer by UK and world standards; nonetheless, it is an important local water source. The use of this aquifer system as a water supply will undoubtedly increase as growth of industry and population continues in the Belfast metropolitan area. Even with the mesic climate of Ireland, groundwater mining of this aquifer system is already occurring, and thus there is a need for detailed aquifer planning and protection to be implemented in order to preserve this resource for the future.     

格尔木河冲洪积扇地下水系统及水资源潜力

格尔木河冲洪积扇区有着巨厚的第四系砂卵砾石层,形成了良好的储水空间,研究其含水层系统特征、地下水循环演化及资源开采潜力对水资源合理开发利用具有重要指导意义。本文基于地质调查、水文地质钻探、动态长观等资料,将含水层系统进行了划分,并对地下水的循环演化进行了阐述。运用补给量总和法、排泄量总和法以及断面径流量法对研究区地下水天然资源量和开采潜力进行了计算。结果表明:研究区河水与地下水经历三次转换,主要模式分为:中高山区模式、冲洪积扇区模式、冲湖积平原区模式;含水层系统可分为:局部循环系统、中间循环系统和区域循环系统三个子系统。研究区地下水天然资源量为206.75×10⁴ m³/d,开采潜力达103.38×10⁴ m³/d,可为下游的盐湖产业基地提供水源保障。     

南水北调东线洪泽湖抬高蓄水位工程效益分析

南水北调东线工程为国家大型调水工程,可有效解决黄淮海平原和山东半岛的缺水问题,可更有效地利用淮河水资源,拟将洪泽湖蓄水位由现在的13.0m抬高至13.5m,增加洪泽湖的蓄水量,减少抽江水量,但抬高蓄水不可避免地会带来负面影响,本文分析了洪泽湖抬高蓄水位的影响和效益,从经济上分析论证抬高蓄水位是可行的.     

下辽河平原南部咸水入侵的数值模拟

建立了地下水水流与溶质的耦合模型,应用FEFLOW软件,对研究区的水位与水质进行了模拟预测.预测结果表明,区内大部分地区明化镇组含水层地下水C1ˉ质量浓度为50～120mg/L,馆陶组为20 ～50 mg,/L.地下水开采15年后咸水界面明显向内陆运移,咸水区北部运移距离大,速度快;咸水区两侧运移距离小,速度慢.模拟预...     

Simulation modelling for groundwater safety in an overexploitation situation: the Maggiore Valley context (Piedmont,Italy)

The Maggiore Valley well field plays a fundamental role in supplying drinking water to a large territory of the Piedmont (north-western Italy). However, an increasing demand for water has led to the overexploitation of the groundwater resources. This situation has caused a progressive drawdown of the piezometric level (locally, up to 0.8 m/year), a spatial reduction in the artesian zone, localised land subsidence and damage to wells. The main purpose of this study was the development of a groundwater flow model of the area for analysing the aquifer response to various pumping strategies. Initially, the groundwater flow simulation (achieved by the application of the MODFLOW code) was calibrated satisfactorily. Then, the groundwater response to four scenarios was simulated to explore the best option to mitigate the problem. In three of the scenarios, a withdrawal reduction of 110 l/s was simulated, whilst considering various relocation options for extraction within the well field. The fourth scenario simulated a withdrawal reduction of 150 l/s; this option also assumed a supplementary water supply from the Monferrato Aqueduct, located north of the study area. All the simulations provided an increase in the piezometric level; in some instances, up to 30 m. Based on these simulations, the most promising management strategy for the Maggiore Valley well field would seem to be the option using a supplementary feed from the Monferrato Aqueduct. In this instance, the predicted piezometric level rise would be up to 25 m; this option also precludes the need for drilling additional wells.     

长江三峡水库回水对洛碛镇浸没的预测

三峡工程正常蓄水水位175 m时,洛碛镇水位达175.5 m,5年一遇洪水位为176.5 m,20年一遇洪水位为180.7 m,百年一遇洪水位为184.9 m。洛碛镇长江高漫滩地表高程低于183 m,属三峡工程浸没区,库区回水形成的浸没现象普遍。本文通过对洛碛镇地层结构和水文地质条件进行分析,结合历史监测资料,建立回归方程和三维非稳定流地下水流系统,采用常规方法和三维数值模型预测回水后洛碛镇地下水雍高,确定浸没范围及相应程度,为地质环境保护策略提供依据。研究表明,研究区为上下两层地下水位的二元结构,上层水位高于下层水位;库水位保持在175.5 m的时间为41 d,上层地下水从175.5 m壅高的总时间为58 d;数值模拟计算结果能较好的匹配地下水壅高实测值;库水位175.5 m时,浸没区面积为0.386 8 km²。     

Evaluation of arsenic contamination potential using indicator kriging in the Yun-Lin aquifer (Taiwan)

Data on the quality of groundwater obtained from several multi-level monitoring wells indicated that arsenic (As) concentration far exceeds the drinking water supply standard in the coastal aquifer of the Yun-Lin, Taiwan. In this study, an estimated As probability risk was computed using indicator kriging to assess the As contamination potential of exceeding the drinking water supply standard in the Yun-Lin county. A three-dimensional (3D) spatial variability model was presented to analyze anisotropically the variation of As concentration using a multi-level threshold indicator variable. This 3D estimator overcomes the scarcity of the data and establishes a vertical correlation of measured As data. The results indicate high As pollution probability in the coastal area and in the Pei-Kang river basin. The highest probability, 0.92, of the As pollution is in the shallow aquifer of the Kou-Hu. The contamination potential of As is primarily within an aquifer depth of 180 m. The contaminated aquifer (<180 m) is not suitable for supplying drinking water. The contamination potential of As is low at the depths of more than 190 m. However, the probabilities associated with the As pollution still exceed 0.2 in the deep aquifer of four coastal townships of the Yun-Lin, and may pose risks to human health if the groundwater is used for drinking.     

南水北调西线一期工程区水文地质条件评价

针对南水北调西线一期工程区地形、地质、地貌和气候条件复杂,及工作条件差、工期短、基础资料缺乏等特点,建立了以遥感水文地质判释为主,结合野外地面调查、现场钻孔地下水流速流向测试、现场钻孔压水试验资料分析、水化学分析、环境同位素测试分析等多手段多方法的水文地质条件综合评价方法,研究了该工程区的地下水类型、地下水化学特征及其形成条件、主要含水层的分布,主要水文地质单元及其地下水运动和补径排条件。结合水利工程勘探的特点,充分利用钻孔压水试验成果,分析探讨水文地质参数及其变化特征,对沿线隧洞涌水量进行初步估算。探讨了主要的水文地质问题。为高山覆盖地区的水文地质条件研究提供了一种新思路。