地下水流模型的建立——以华北平原为例

地下水流模型是辅助地下水资源量评价的一种工具,采用的建模方法主要是有限元法、有限差分法和边界元法。基于有限元法的地下水流模型包括地下水概念模型、数学模型、数值模拟模型3部分。概念模型建立包括含水层结构概化、研究区边界概化及水力特性确定3个步骤;数学模型和数值模拟模型建立包括数学方程式描述、区域剖分、定解条件处理、源汇项、水文地质参数确定、模型识别与检验及水量均衡分析7个步骤。以华北平原地下水流模型为例,阐述建模过程。     

海河流域华北平原浅层地下水模型研究

由于对海河流域平原区地下水资源缺乏有效的管理,致使其严重超采,进而产生了一系列地质灾害,制约着经济社会的可持续发展.通过分析区域水文地质条件、含水层空间分布规律、水文地质参数、地下水流场、地下水观测资料等,概化研究区地质体,进而建立地下水模型,同时率定模型和标定大型漏斗.该模型首次全面认知和模拟了研究区地下水超采起始时间、超采量、漏斗发展过程,并预测了发展趋势.     

基于非均质强弱程度评价GMS求参模块适用性

GMS软件中MF2K PES Process和PEST模块都是参数估算程序,两模块在参数运算过程中交替调用、反复迭代,得到最优的参数值。对于精度要求高、水文地质条件复杂的地下水流模型,GMS反求参数模块的适用性需进行有效验证。以地下含水岩层的非均质性为唯一变量,采用高斯模拟法生成非均质程度不同的渗透系数场,建立给定水文地质参数的理想地下水流模型,进行模型识别,得到等效渗透系数。分析可得,GMS软件反求参数模块的计算精度与水文地质条件有一定的相关性,均质含水层参数估算结果与给定值基本吻合。而含水层非均质性越弱,估算结果精度越高,误差越小,反之计算结果误差越大,为水文地质参数的计算提供借鉴及依据。     

桦南县地下水数值模拟研究

在分析桦南县城区地质及水文地质条件的基础上,运用GMS软件建立了三维地质结构模型。根据研究区的实际条件建立了水文地质概念模型,据此建立地下水流三维数学模型,并运用Visual MODFLOW软件进行求解。模型识别和验证的结果表明,模型对于含水层结构、含水层边界条件概化及水文地质参数选取较为合理,能够真实反映研究区水文地质条件。在多年平均降水量和现状开采量下,对研究区地下水位动态进行了预报,并提出了水资源合理开发利用的建议。     

河北省某扩建煤矿地下水流场变化数值模拟

为了分析河北某扩建煤矿地下水流场的变化特征,在调查分析研究区水文地质条件的基础上,采用数值模拟技术,利用Visual Modflow软件建立地下水数值模拟模型,基于实测数据对模型进行识别和验证。利用识别后的模型预报未来矿山开采过程中不同含水层水位的变化特征,分析矿山排水对各个含水层的影响。结果表明:矿山扩建后,矿山附近各含水层地下水水位均出现下降,但不同含水层下降幅度不同,其中第3和第4含水层受疏干排水影响较明显,水位下降幅度大;随着矿山长期抽水,第3和第4含水层中地下水降落漏斗范围逐步扩大。     

母猪河地下水库初步规划方案介绍

母猪河地下水库位于威海市文登区母猪河流域,库区为一个独立的水文地质单元,有一定的含水层厚度,有较丰富的潜流,地层富水性和透水性强。该文根据补给水源条件、水文地质条件、环境地质条件、地下水开采条件论述母猪河地下水库建库可行性,通过"一截一蓄",兴建地表橡胶坝及地下截渗墙等工程体系,人为干预地下水流的天然调蓄能力,扩大地下含水层蓄水能力,可增加当地雨洪资源利用量。     

GMS在地下水流场预测中的应用研究

文中以内蒙古某地地下水含水层为例,建立了地下水含水层水文地质概念模型及数学模型,采用GMS软件MODFLOW模块对模型识别验证求解,对不同开采条件下的地下水流场变化情况进行模拟发现,在现状开采强度每年增长2％的基础上,研究区地下水位较为平稳,能够较大地发挥地下水开采潜力,对该区未来地下水资源开发利用提供技术支持.     

基于FEFLOW傍河水源地地下水数值模拟

文章根据研究区的水文地质特征,建立了水文地质概念模型和地下水流数值模拟模型,对该模型进行了识别和验证.对新的开采方案下的地下水状况进行模拟.     

锡林浩特市地下水数值模拟模型建立

以锡林浩特市为研究区,在详细分析研究区的区域地质、水文地质、水资源开发利用动态等的基础上,通过水文地质补充调查与勘查,全面系统地掌握研究区的水文地质条件,划分含水层,确定模型边界条件,应用Rock Works16构建研究区水文地质概念模型。在此基础上,应用Visual MODFLOW软件建立起锡林浩特市地下水三维数值模拟模型,通过流场拟合和单井地下位过程线拟合进行模型的参数识别和验证,以检验所建立模型的适用性和准确性。     

青海省格尔木市某地水文地质调查研究

通过对青海省格尔木市某地进行水文地质调查研究,查明该地及其所处区域水文地质和环境地质条件,主要包括含(隔)水层结构及分布特征、地下水补径排条件、地下水流场、地下水动态变化特征、各含水层之间及地表水与地下水之间的水力联系,通过分析评价,该地目前水资源相对比较丰富,但天然包气带防污性能弱;提出要合理开发利用水资源优化管理,避免对地下水污染,实现可持续发展;建议建立格尔木流域地下监测网,掌握地下水动态,为科学管理提供依据。     

Conjunctive Management of Large-Scale Pressurized Water Distribution and Groundwater Systems in Semi-Arid Area with Parallel Genetic Algorithm

This study develops a production well management model for the conjunctive management of water resources in semi-arid areas. The management model integrates a large-scale pressurized water distribution system and a three-dimensional groundwater model under an optimization framework. The well pump operations optimization problem is formulated as a Boolean integer nonlinear programming (BINLP) problem to optimize the periodic 24-h pump on/off operations over a 1-week operation horizon. The management model considers multiple objectives and is solved by a parallel genetic algorithm (PGA) to overcome the difficulty of solving the BINLP problem. The PGA significantly reduces computation time for a case study in Chandler, Arizona. The Chandler water distribution model is built based on EPANET, and the Chandler three-dimension groundwater model is developed using MODFLOW. The high performance computing (HPC) of the genetic algorithm makes it possible to obtain 24-h real-time operations in the 7-day forecast model. The tank reliability, resilience, and vulnerability (R-R-V) are evaluated to infer the system reliability. The Pareto curve provides compromise solutions between the two competing objectives of energy reduction and pressure violation reduction.     

Regional management modeling of a complex groundwater system for land subsidence control

The three-dimensional groundwater flow model MODFLOW and the one-dimensional consolidation model are coupled and calibrated to simulate the piezometric levels and land subsidence in the complex multi-aquifer system of the lower Central Plain of Thailand. The mathematical models are calibrated against historical data for the period 1955–1990 by considerably updating the system conditions used by previous studies. The aquifer system responses to different pumping schemes are then predicted for the period 1991–2010. The modeling procedure is carried out in close consultation with the Department of Mineral Resources (DMR), Royal Thai Government. The conclusions of the study will allow the DMR to develop and implement updated groundwater management policies, land subsidence control strategies and action programs in the Bangkok Metropolitan Area.     

Groundwater Allocation Using a Groundwater Level Response Management Method—Gnangara Groundwater System, Western Australia

The Gnangara groundwater system (Gnangara system) is an important source of groundwater for Perth, Western Australia: in the order of 350 GL of groundwater is abstracted annually. The Gnangara system also sustains groundwater dependent ecosystems (GDEs), mostly wetlands and native vegetation. Declining groundwater levels across the system have led to impacts on a number of key GDEs. Western Australia’s Department of Water recently prepared a Water Management Plan for the Gnangara system. Allocation limits were reviewed as part of the plan preparation. To assist in reviewing allocation limits, an adaptive Groundwater Level Response Management (GWLRM) methodology was developed and implemented. This paper describes the methodology and its application to the Gnangara system. The methodology was developed to be used as a corrective tool for the short- and medium-term, to assist in achieving long-term sustainability of groundwater management in the context of changing climate and declining groundwater levels. The GWLRM methodology is based on groundwater storage depletion and can be applied to existing allocation limits as an interim tool to assist in making management decisions aimed at recovering groundwater resources. The key to the GWRLM correction is that it will direct water allocation towards sustainable levels on the basis of measured trends. Allocations corrected through application of the GWRLM would therefore represent interim and improved water allocation figures. GWLRM can also identify potential problem areas where the principles or calculations used for long-term sustainable groundwater allocation would need to be reviewed. For the Gnangara system, the calculated storage changes or GWLRM corrections were considered together with results of predictive modelling as part of an expert panel process to derive a more sustainable interim groundwater allocation regime while further research is being completed.     

五常镇地下水水文地质特征分析

五常镇以农耕为主,为稻米之乡。五常镇70km2范围内区域的水文地质条件,受区域第四纪地质、地貌、水文和气象等因素的控制,形成了区域地下水系统的基本格局。研究地下水水文地质条件,包括地下水的赋存条件、补径排条件、类型和动态规律等,从而得出移动规律,为地下水量的计算提供基础资料,为五常镇地下水资源的评价提供水文地质依据。     

Groundwater management and development by integrated remote sensing and geographic information systems: prospects and constraints

Groundwater is one of the most valuable natural resources, which supports human health, economic development and ecological diversity. Overexploitation and unabated pollution of this vital resource is threatening our ecosystems and even the life of future generations. With the advent of powerful personal computers and the advances in space technology, efficient techniques for land and water management have evolved of which RS (remote sensing) and GIS (geographic information system) are of great significance. These techniques have fundamentally changed our thoughts and ways to manage natural resources in general and water resources in particular. The main intent of the present paper is to highlight RS and GIS technologies and to present a comprehensive review on their applications to groundwater hydrology. A detailed survey of literature revealed six major areas of RS and GIS applications in groundwater hydrology: (i) exploration and assessment of groundwater resources, (ii) selection of artificial recharge sites, (iii) GIS-based subsurface flow and pollution modeling, (iv) groundwater-pollution hazard assessment and protection planning, (v) estimation of natural recharge distribution, and (vi) hydrogeologic data analysis and process monitoring. Although the use of these techniques in groundwater studies has rapidly increased since early nineties, the success rate is very limited and most applications are still in their infancy. Based on this review, salient areas in need of further research and development are discussed, together with the constraints for RS and GIS applications in developing nations. More and more RS- and GIS-based groundwater studies are recommended to be carried out in conjunction with field investigations to effectively exploit the expanding potential of RS and GIS technologies, which will perfect and standardize current applications as well as evolve new approaches and applications. It is concluded that both the RS and GIS technologies have great potential to revolutionize the monitoring and management of vital groundwater resources in the future, though some challenges are daunting before hydrogeologists/hydrologists.     

Integrated Biophysical and Economic ModellingFramework to Assess Impacts of Alternative Groundwater Management Options

We developed an integrated biophysical and economic modeling framework to assess impact of various groundwater management options on seawater intrusion and waterlogging and ultimate impact on sugarcane profitability in a coastal region of North Queensland, Australia. The modelling framework used the output of a groundwater management flow model (waterlogged and seawater intruded areas) and a crop simulation model (simulated crop yield) and maximised the net revenue in a mathematical programming (optimisation) model. The framework determined the economically optimal level of water use on different soil types and in different management regimes and estimated impact of seawater intrusion and waterlogging on net revenue of growing sugarcane in two neighbouring water board areas (North Burdekin Water Board – NBWB and South Burdekin Water Board – SBWB). In NBWB, the predicted aggregate net revenue was highest ($19.95 million) when groundwater use was also highest (70%) while predicted aggregate net revenue was lowest when groundwater use was also lowest. In SBWB, the predicted aggregate net revenue was highest ($23 million) when groundwater use was relatively low (61%). The predicted aggregate net revenues of all the management options were higher in SBWB than NBWB.     

潜水蒸发与埋深关系模型研究

本文是通过多年野外对潜水蒸发的模拟，分析了潜水蒸发与埋深之间的关系。发现潜水蒸发与埋深关系曲线呈双曲线形，提出了潜水蒸发与埋深关系模型，模型的应用将为地下水资源计算、盐碱地改良提供科学依据．     

Estimating Regional Groundwater Recharge Using a Hydrological Budget Method

Estimating groundwater recharge is a key component in determining the sustainable yield of groundwater resources in arid and semi-arid areas such as southern California. Estimating groundwater recharge on a regional scale requires developing a water budget that incorporates data on boundary conditions, aquifer properties, groundwater levels, and groundwater production. The hydrological budget method proposed herein is simple, cost-effective, and easy to apply. It utilizes matched pairs of groundwater level measurements, groundwater extraction data, and distributed specific yield information for estimating groundwater recharge. In this method, ARCGIS 9.0 Geostatistical and Spatial Analyst applications are used for interpolating/extrapolating and creating grids for specific yield, bedrock elevation, and raw groundwater data. The annual average groundwater recharge for the Hemet subbasin in western Riverside County, California, from 1997 to 2005 is estimated at 12.5 MCM, with wet and dry periods ranging between 14.9 MCM and 11.7 MCM, respectively. The proposed method utilizes information commonly available to most groundwater management entities, such as groundwater production data, groundwater level measurements, and lithologic information.     

Prediction and simulation of monthly groundwater levels by genetic programming

Groundwater level is an effective parameter in the determination of accuracy in groundwater modeling. Thus, application of simple tools to predict future groundwater levels and fill-in gaps in data sets are important issues in groundwater hydrology. Prediction and simulation are two approaches that use previous and previous-current data sets to complete time series. Artificial intelligence is a computing method that is capable to predict and simulate different system states without using complex relations. This paper investigates the capability of an adaptive neural fuzzy inference system (ANFIS) and genetic programming (GP) as two artificial intelligence tools to predict and simulate groundwater levels in three observation wells in the Karaj plain of Iran. Precipitation and evaporation from a surface water body and water levels in observation wells penetrating an aquifer system are used to fill-in gaps in data sets and estimate monthly groundwater level series. Results show that GP decreases the average value of root mean squared error (RMSE) as the error criterion for the observation wells in the training and testing data sets 8.35 and 11.33 percent, respectively, compared to the average of RMSE by ANFIS in prediction. Similarly, the average value of RMSE for different observation wells used in simulation improves the accuracy of prediction 9.89 and 8.40 percent in the training and testing data sets, respectively. These results indicate that the proposed prediction and simulation approach, based on GP, is an effective tool in determining groundwater levels.     

GIS-Based Groundwater Management Model for Western Nile Delta

The limited availability of renewable fresh water is a major constraint on future agriculture and urban development in Egypt. The main water resource that Egypt has been depending on is the River Nile. Nowadays, the role of groundwater is steadily increasing and will cover 20% of the total water supply in the coming decades especially in the reclaimed areas along the desert fringes of the Nile Delta and Valley. Abstraction from groundwater in Egypt is dynamic in nature as it grows rapidly with the expansion of irrigation activities, industrialization, and urbanization. One of these areas is the Western Nile Delta in which the groundwater is exploited in many localities. To avoid the deterioration of the aquifer system in this area, an efficient integrated and sustainable management plan for groundwater resources is needed. Efficient integrated and sustainable management of water resources relies on a comprehensive database that represents the characteristics of the aquifer system and modeling tools to achieve the impacts of decision alternatives. In this paper, a GIS-based model has been developed for the aquifer system of the Western Nile Delta. The GIS provides the utilization of analytical tools and visualization capabilities for pre-and post-processing information involved in groundwater modeling for the study area. The developed model was calibrated for steady state and transient conditions against the historical groundwater heads observed during the last 20 yr. The calibrated model was used to evaluate groundwater potentiality and to test two alternative management scenarios for conserving the aquifer system in Western Nile Delta. In the first scenario, reducing the surface water inflow while increasing the annual abstraction from groundwater by about 450 million m³ and improving the irrigation system could increase the net aquifer recharge by about 5.7% and reduce the aquifer potentiality by about 91%. Constructing a new canal as a second management scenario could increase the annual aquifer potentiality by about 23%. The GIS-based model has been proven to be an efficient tool for formulating integrated and sustainable management plan.