Groundwater flow model of the Pipiripau watershed, Federal District of Brazil

In order to understand the groundwater dynamics and to improve the management of water resources in the Federal District of Brazil, this research proposes a 3D groundwater flow model to represent the groundwater level and flow system. The selected test site was the Pipiripau catchment. The development of the model was based on available geological, hydrogeological, geomorphological, climatological and pedological data. Geological and hydrogeological data were used to generate the 3D groundwater flow model. The 3D mesh elements of the domain were generated through the Groundwater Modeling System software, based on the logs of the well materials. The numerical simulation of the finite element method was implemented in the framework of the scientific software OpenGeoSys. With the 3D mesh-appropriated boundary conditions, annual average infiltration data and hydrogeological parameters were incorporated. Afterwards, the steady-state model was calibrated by the PEST software using available data of the water level from wells. The results showed the distribution of the steady-state hydraulic heads in the model domain, where the highest values occurred in the east and west recharge areas and the lowest values were found in the southwest of the basin. The results of this study can be a used as initial condition for the transient groundwater flow simulation and to provide a scientific basis for water resource management.     

泸西喀斯特断陷盆地地表水与地下水流域边界与水动力性质

在详细调查基础上,采用系统科学及水文地质分析方法,依据地形地貌、地层岩性、地质构造、示踪试验、地下水排泄基准面、喀斯特发育条件及发育规律等剖析论证流域边界,并通过钻探及示踪试验进行验证。研究结果:（1）对泸西喀斯特断陷盆地南东部的水系统边界向北移进行了修正,证实了三塘一带深部不发育的喀斯特是地下水分水岭边界,使得泸西喀斯特断陷盆地流域的径流系统和边界圈化更加准确;（2）泸西喀斯特断陷盆地流域地表水、地下水转化频繁,地表水径流特征主要以小江河在水库、河流、伏流间的径流转化过程为体现,地下水在侵溶山区接受大气降水补给后,上层径流以泉、暗河的形式在泸西盆地底面排泄后转化成地表水,最终汇集于盆地南部、通过工农隧洞及落水洞排向小江,而下层径流则以小江水面为基准,通过深层径流排泄。      

Climate and irrigation scenario analyses using three-dimensional numerical modelling: a case study of the Nasia sub-basin in the White Volta Basin,Ghana

A groundwater resource characterisation and assessment model was developed for Nasia river sub-basin in the White Volta Basin, Ghana. The model is useful to policymakers for planning and sustainable management of groundwater resources in the basin for domestic and irrigation purposes. A conceptual model was constructed that characterized boundary conditions and hydrostratigraphy, and estimated recharge rates and hydraulic and storage parameters. From current understanding of the hydrogeological dynamics, three hydrostratigraphic layers were delineated. The conceptual model was converted to a three-dimensional steady-state groundwater flow model using MODFLOW. Recharge rates estimated from the base model indicate a minimum of 1.1% and maximum of 6.2% of the total rainfall. The hydraulic conductivity ranged between 0.20 and 15 m/day. Four possible scenarios were simulated: (1) increased population, (2) climate variations (reduced recharge), (3) increased abstraction for irrigation, and (4) worst-case scenario which is a combination of the first three scenarios. Results from scenarios 1 and 2 indicated that, under such conditions, the groundwater resources could be sustained and no significant effect on any of the water budget indicators was observed. For scenario 3, there was significant drop in hydraulic head in the central portions of the study area. The scenario 4 simulation indicated that there was significant reduction in groundwater levels and groundwater discharge into streams under these stressors. Such reduction can affect stream levels in the basin and, subsequently, the ecosystem. These findings are valid within the limits of uncertainty in the hydrogeological data that were used in this study.

     

王河煤矿矿井涌水量数值模拟及预测

针对岩溶充水矿井涌水量数值模拟中边界条件概化和非均质性刻画难题,采用分别建立区域模型和局部模型的方法解决边界概化问题,运用信息复合技术刻画岩溶介质的非均质性.以具有完整水文地质边界的荥巩矿区为计算区建立区域模型,以区域模型计算出的流量作为边界条件建立王河煤矿矿井涌水量模拟模型(局部模型).在充分分析钻孔、构造、突水、物探等资料的基础上,运用信息复合技术对煤矿充水含水层进行垂向和平面参数分区.在此基础上,利用GMS建立了精细的王河煤矿涌水量模拟模型.利用该模型预测了不同开采工作面的矿井正常涌水量和最大涌水量.结果表明,开采111070、113090、113110、113120工作面时,正常涌水量分别为490、350、560、590 m3/h,最大涌水量分别为690、490、790、830 m3/h.预测结果可为矿山设计部门确定开采方案、布置排水设备和制定防治水措施提供科学依据.      

干旱区高山-盆地系统深部水资源的赋存和估算——以河西走廊西段为例

现行西北地区水资源评价，是基于下列水文地质概念模型：（1）作为主要补给源地的山区，其与盆地之间存在“阻水屏障”；（2）山区形成的地下水基本上已全部汇入出山河谷，流向盆地绿洲，经实地勘探水化学同位素分析与资料研究，认为现行“模型”不符合地质实际。在引用国外高山区产流数值模拟成果的基础上，采用比拟法估算出研究区，由山区通过基岩向盆地绿洲作侧向补给的大致数量。新概念模型的建立，意味着西北高山－盆地系统的绿洲基岩不深处，赋存有相当数量以前未被计入的、可供开发的水资源。     

砚山县平远干旱盆地地质构造赋水性探论

平远盆地属地质构造和水文地质条件特别复杂的高原裸露型岩溶盆地,洞穴资源十分丰富,但找水十分困难。盆地大水量的水文井与地质构造有关,特别是与断裂构造关系密切。富水块段都处在特殊地质构造位置和水文地质单元上,这些规律性对探索平远盆地找水方向和选择供水井位置大有益处。     

乌鲁木齐河流域北部平原地下水流模拟

本文运用数字水文地质概念模型的方法建立了乌鲁木齐河流域北部平原的地下水流模型,并用流量边界与柴窝堡盆地和河谷区的地下水流模型相接,构成一个统一的流域地下水模型,为乌鲁木齐河流域水资源整体规划利用提供了模拟分析工具。北部平原的南部倾斜平原为砂卵砾石组成的大厚度潜水含水层,北部细土平原为多层结构。地下水总体上由南向北径流,天然状态下在交界地带溢出成泉或流入沙漠。目前,地下水循环基本上由人为控制。农田灌溉回归补给量与河流和山前侧向补给量持平;而开采量已是绝对的排泄量。季节性开采造成地下水位季节性大幅度变化。水位的下降使蒸发蒸腾量减少,减轻了由于灌溉造成的土壤盐碱化问题。     

基岩岛屿地下水流场数值模拟研究

岛屿是我国领土的重要组成部分,对国家安全和国防军事意义非凡。岛屿的地下水资源尤为珍贵,地下水流场模拟是研究地下水分布规律的重要手段。水文地质条件复杂、可利用的观测井较少等原因,造成了基岩岛屿水文地质模型概化精度不高、初始条件难以获取等问题。为克服基岩岛屿地下水流场模拟的诸多困难,将珠海外伶仃岛作为研究区,利用数字高程模型数据开展地质地貌建模; 利用探地雷达法、直流电法与地质分析对岛屿进行探测,获取了地层数据; 采用地下水遥感评估法,利用实测井位数据,确定了地下水的初始水位,进而对基岩岛屿地下水流场进行建模; 最终,通过对外伶仃岛地下水流场的数值模拟得出地下水模拟流场图。岛上多个测点的探测水位值与模拟水位相关性较好,其拟合优度R²为0.872 2。由此可见,综合遥感、物探、水文地质手段等技术方法获取的数据,采用地下水模拟软件或程序实现基岩岛屿地下水流场的数值模拟,是基岩岛屿地下水资源研究的一个有效方法。     

Assessment of aquifer vulnerability based on GIS and DRASTIC methods: a case study of the Senirkent-Uluborlu Basin (Isparta, Turkey)

Aquifer vulnerability has been assessed in the Senirkent-Uluborlu Basin within the Egirdir Lake catchment (Turkey) using the DRASTIC method, based on a geographic information system (GIS). There is widespread agriculture in the basin, and fertilizer (nitrate) and pesticide applications have caused groundwater contamination as a result of leaching. According to hydrogeological data from the study area, surface water and groundwater flow are towards Egirdir Lake. Hence, aquifer vulnerability in the basin should be determined by water quality in Egirdir Lake. DRASTIC layers were prepared using data such as rainfall, groundwater level, aquifer type, and hydraulic conductivity. These data were obtained from hydrogeological investigations and literature. A regional-scale aquifer-vulnerability map of the basin was prepared using overlay analysis with the aid of GIS. A DRASTIC vulnerability map, verified by nitrate in groundwater data, shows that the defined areas are compatible with land-use data. It is concluded that 20.8% of the basin area is highly vulnerable and urgent pollution-preventions measures should be taken for every kind of relevant activity within the whole basin.     

Groundwater flow modelling in the central zone of Hanoi, Vietnam

On the basis of a review of the Quaternary sedimentary architecture in the area of Hanoi city (Vietnam), a numerical, deterministic and three-dimensional groundwater flow model has been built for a simulation between 1995 and 2004. The sedimentary architecture has been constructed on the basis of the data from 32 drillings covering the entire Quaternary sequence (but with little sedimentological detail), as well as hydrographical and hydrogeological data. Both steady- and transient-state conditions were tested. Results calculated by the model seem to indicate that the conceptual hypotheses adopted are reasonable for the modelled domain and period. The simulation allows for calculation of the regional groundwater flow trends. It is also used for assessing the relative importance of the various recharge sources of the shallow aquifer system in Hanoi, and for estimating the interactions between groundwater and the Red River.     

山东淄博市地下水资源评价及其合理开发利用研究

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。     

庄里水库建设对地下水水位的影响

庄里水库位于羊庄盆地水文地质单元内,水库建设将使地下水补径排条件和流场发生改变,根据羊庄盆地水文地质条件、地下水开发利用状况,采用Visual Madflow4．1软件,建立地下水水流模型,模拟庄里水库建成后对地下水水位和流场的影响,提出地下水水源保护措施。     

Hydrological and hydrogeological characteristics of Wadi el Mujib catchment area,Jordan

Hydrological and hydrogeological data in the area have been verified to evaluate the availability and the potentiality of the water resources for the proposed damsites in the Wadi el Mujib catchment area, which is considered a semiarid to arid region. The quantity of the surface waters is very small compared with the surface area of the basin, however, due to the shortage of precipitation in the country and the necessity to attain socioeconomic objectives, the investigation of these waters has become more vital. The most reliable exploitation can be essentially achieved by constructing small storage dams on the suitable sites in order to benefit from the flood waters coming from the main wadis. For the above purpose, the hydrogeological and hydrological study of Wadi el Mujib catchment area was carried out, where the Wadi Mujib dam site will be constructed. The hydrogeological investigation of the groundwater was performed by constructing a groundwater contour map of the Amman-Wadi Es Sir aquifer (B2/A7) so as to verify the groundwater flow system and to determine the potentiality of the aquifer from the hydraulic parameters obtained from the pumping test analysis. The hydrological feasibility study of the dam was carried out by evaluating the water balance for a long-term period (1970 to 1990) in order to obtain reliable data that can be used to estimate the recharge to B2/A7 aquifer. In addition, a frequency analysis was performed to estimate the flood design of the reservoir area as well as the spillway at the proposed dam site.     

新疆三塘湖盆地水文地质条件及铀成矿前景分析

新疆三塘湖盆地是具有正向水文地质和水文地球化学分带的渗入型坳陷盆地,区内含水层发育良好,具有较好的泥-砂-泥结构模式,盆地铀源丰富,地下水中铀元素的分布规律有利于其在氧化还原过渡带中沉积富集,具有较好的铀成矿前景。     

黄河数字流域模型的建立和应用

黄河数字流域模型是“数字黄河”的重要组成部分,在数字流域模型框架下,以坡面为基本单元,建立了包括植被截留、融雪、地表蓄滞、表层土蓄滞、中层土蓄滞和深层土蓄滞共6层的产流模型.模型在垂向上考虑3层出流:地表超渗产流、表层土侧向渗流和中层土侧向渗流,既反映当前的降水过程,又体现前期降水过程和土壤前期含水量的影响,比较适合黄河流域的产流特点.在坡面产流的基础上,还给出了坡面单元侵蚀产沙公式,用于建立流域产沙数学模型.应用建立的模型,给出了3个计算实例:黄河全流域水量计算、小花区间汛期洪水模拟和多沙粗沙区产沙计算.实践表明:建立的模型基本具备了在黄河全流域进行降雨-径流模拟、侵蚀产沙计算的功能,辅以降雨预报模块则可进行洪水预报.     

Numerical modeling of the transient hydrogeological response produced by tunnel construction in fractured bedrocks

Groundwater inflows into tunnels constructed in fractured bedrocks not only constitute an important factor controlling the rate of advancement in driving the tunnel but may pose potential hazards. Drawdowns caused by tunnel construction may also induce geotechnical and environmental impacts. Here we present a numerical methodology for the dynamic simulation of the hydrogeological transient conditions induced by the tunnel front advance. The methodology is based on the use of a Cauchy boundary condition at the points lying along the tunnel according to which water discharge, Q, is computed as the product of a leakage coefficient, , and the head difference, (H−h), where H is the prescribed head at the tunnel wall and h is the hydraulic head in the fractured rock in the close vicinity of the tunnel. At a given position of the tunnel, is zero until the tunnel reaches such position when it is assigned a positive value. The use of step-wise time functions for allows an efficient and accurate simulation of the transient hydrogeological conditions at and around the tunnel during the excavation process. The methodology has been implemented in TRANMEF-3, a finite element computer code for groundwater flow in 3D fractured media developed at the University of A Coruña, Spain, and has been used to simulate the impact of a tunnel on the groundwater system at the Äspö island (Sweden). This tunnel was constructed to access an underground laboratory for research on radioactive waste disposal. The large amount of available data at this site provides a unique opportunity to test the performance of the numerical model and the proposed methodology for tunnel advance. With just minor calibration, the numerical model is able to reproduce accurately the measurements of inflows into the tunnel at several reaches and hydraulic heads at surface-drilled boreholes. These results obtained at the Äspö site lead us to conclude that accurate predictions of the transient hydrogeological responses induced by tunneling works in fractured bedrocks, can be achieved provided that a sound hydrogeological characterization of large-scale fracture zones is available.     

基于GMS的傍河应急水源地地下水资源评价

依据铜陵太平－钟仓应急水源地水文地质条件构建水文地质概念模型.在此基础上,利用三维可视化软件GMS建立水源地地下水流数值模拟模型,并对模型进行了识别和验证.模型模拟期为一个应急供水周期180 d（2017－01～2017－06）,水源地开采层位为承压水.模拟结果表明：在采用均匀布井方案和限定开采井水位降深不超过承压含水层顶板的条件下,水源地允许开采量为11.94×10⁴ m³/d,达大型水源地规模（5×10⁴ m³/d<允许开采量<15×10⁴ m³/d）;水源地承压水在应急开采条件下,激发了长江侧渗补给量,袭夺量占水源地开采总量的27.82%.同时,通过模型模拟数据对傍河水源地地下水与地表水转换规律进行了初步探讨.     

陇东盆地白垩系含水层水文地质参数求解

陇东盆地水资源短缺,严重制约着经济发展,近年来探明白垩系洛河组地层赋存巨厚深层地下淡水。含水层水文地质参数的求解是深层地下水资源评价的关键,用抽水试验确定深层承压含水层水文地质参数是水文地质勘查研究的一项重要的内容。根据单孔、多孔、干扰抽水试验资料,采用稳定流、非稳定流多种方法求解陇东盆地深层含水层水文地质参数,避免了单一方法的偶然性、随意性,计算结果可信。最后探讨了抽水试验场地水文地质条件与所选取公式理论条件的差异对计算结果的影响。      

Groundwater in Nigeria – a millennium experience – distribution,practice, problems and solutions

Lack of appropriate hydrogeological base maps, poor knowledge of the geology of the Nigerian terrain, lack of infrastructural facilities and absence of a working legislature beset the practice of hydrogeology causing problems in exploration, exploitation, operation, control and management of the abundant groundwater resources of Nigeria. This study shows that Nigeria has about 224 trillion l/year of surface water and about 50 million trillion l/year of groundwater for a population of about 128 million. Domestic consumption need was about 6.0 billion l/year in 2001, indicating that there is an abundant water resource potential. A hydrostratigraphic basin delineation is attempted with ten hydrogeological basins as hydrogeological units, which bring to light the intrinsic causes and solutions to the problems of borehole failures, dam collapses, brine-salt water intrusions, and insufficient water delivery to millions of Nigerians. Electronic Publication     

山东荣成沽河流域水资源系统分析

流域水资源系统由降水产流，以及通过水文下垫面的转换，形成的地表径流和地下水流流组成。本文将复杂的沽河流域水 资源系统分解成多个子系统，利用频谱分析方法对各个水资源子系统的转换功能进行定量的分析刻画，并利用地下含水介质子系统的转换特征函数－频率响应函数求取水文地质参数，丰富了水文地质参数的获取途径。