孔隙承压水盆地超采评价与限采规划

为客观评价孔隙承压含水层的超采程度，以地下水资源的可循环再生能力作为可持续开采的约束，通过对各项补给的来源、途径和性质的分析，确定可持续开采量的构成。文中以安徽淮北平原西部孔隙承压水盆地超采评价为例，对上述过程进行阐述，结合承压水流系统的数值模型，评价研究区的可持续开采量和超采程度，并在此基础上，提出限采规划方案。     

人类开采活动影响下的衡水地区地下水水质特征及演化

衡水地区地下水普遍存在"上咸下淡"的水质格局,受深部淡水持续超采影响,浅层咸水有逐年下移而使淡水咸化的趋势。选择衡水地区典型剖面,通过水质长期监测,结合地下水开采情况,分析2011至2014年该剖面上地下水水位与水质监测资料,总结了衡水地区地下水水化学特征及其演化规律。研究结果表明,浅层含水层中水平径流微弱,地下水水质由西向东逐渐好转,其中西部地下水离子浓度变化较大;深部含水层中水平径流明显,地下水水质整体良好,但有逐年恶化的趋势;人类开采活动一定程度上增强了浅层和深层含水层间的水力联系,使二者中离子浓度随时间的波动呈现出一定的相关性。     

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.     

Aquifer Management with Logistic Recharge

Abstract

Theoretical principles of sustainable aquifer management are laid out in this work. The premise of our treatment is that groundwater is a renewable, although exhaustible, natural resource. The theory of this work is aimed at aquifers with a relatively homogeneous recharge that can be approximated by a logistic growth function. Sustainable aquifer exploitation occurs when the rate of ground-water extraction is equal to or less than the natural rate of groundwater replenishment for any level of aquifer storage. There can be many levels of sustainable aquifer exploitation depending on the level of aquifer storage, but there may be only one that maximizes economic returns under a variety of economic and aquifer conditions. Different strategies for sustainable exploitation are derived depending on whether or not the analysis considers tradeoffs among: (i) current and future exploitation; (ii) constant and dynamic aquifer storage conditions; and (iii) regulated and unregulated aquifer exploitation. Key factors affecting sustainable exploitation strategies include: (1) the market price of groundwater; (2) the cost of groundwater extraction; (3) the aquifer storage and natural replenishment characteristics; (4) institutional and environmental regulations on groundwater extraction; and (5) the real discount rate. An example of sustainable groundwater exploitation in Santa Barbara, California, illustrates the methods of this article.     

信息融合型页岩气开采区含水层富水性预测——以凤冈区块为例

页岩气在开采过程中不但容易污染地下水资源,而且还需要大量的水资源来保障水力压裂技术的用水量,因此预测页岩气开采区的地下水富水性对于合理保护和利用页岩气开采区的地下水资源具有重要的意义。在总结岩溶地区含水层富水性主要控制因素的基础上,利用层次分析方法(AHP)建立了融合多源信息的含水层富水性评价模型,确定了因素权重,然后利用地理信息系统(GIS)技术的信息处理和空间展示功能制作了各富水性影响因素专题图,并对各专题图进行了信息融合叠加,最终完成了凤冈页岩气开采区的含水层富水性评价预测。基于GIS技术的信息融合型含水层富水性评价方法可以有效地反映含水层富水性这一受控于多因素影响且具有非常复杂形成机理的非线性动力现象,可为页岩气开采区的地下水资源利用与保护提供依据。     

我国地下水地球物理勘查中的问题及对策

针对我国地下水地球物理勘查目前面临的成淡水地区寻找淡水体、基岩山区裂隙水勘查、深层含水体勘查、岩溶石山地区岩溶水勘查、红层地区浅层地下水勘查等主要问题，从水文地质问题、采用的物探技术方法及其结合实例解决上述问题的对策等角度进行综述，同时对地球物理勘查地下水发展趋势予以分析。     

Optimizing Safe Yield Policy Implementation

The presented method enhances groundwater-mandated safe yield management. It is useful for settings that prevent sustained yield or integrated management. To protect hydraulically connected surface water rights, the Utah government’s Cache Valley groundwater management plan proposes that total pumping increase not exceed 84,431 m³/day. To determine how best to spatially distribute additional allowable pumping, stakeholders quantified limits defining acceptable impacts on selected water resource indicators. A new simulation–optimization (S–O) algorithm used these limits while computing optimal spatially distributed perennial yield or safe yield groundwater pumping extraction strategies. The limits prevent unacceptable decreases in: head and net flow between aquifer and surface waters (rivers, surface/subsurface drains, springs, lakes). The optimization objective function maximizes weighted pumping to provide water for 18 growing municipalities. For 16 perennial yield scenarios, computed optimal pumping increases differ in protectiveness toward senior water rights, and range from 16% to 103% of the state plan-proposed increase. Implementing a protective strategy would achieve 90% of the storage changes needed to reach equilibrium within 23 years. Indicator potentiometric heads would reach equilibrium within 10–40 years. At equilibrium, an optimal Cache Valley perennial yield strategy acceptably minimizes net annual non-pumping discharges. By comparison, multi-period 20-year transient groundwater mining optimizations allow more pumping in early years. Pumping then must decline to satisfy seepage and head constraints through year 20. Adverse seepage impact would increase for years thereafter. For situations governed by safe or perennial yield policy, equilibrium-based (steady-state) optimization is very useful. It effectively develops optimal perennial yield strategies.     

Management of High Groundwater Level Aquifer in the Taipei Basin

Groundwater pumpings have been prohibited by the government since 1970 due to the overexploitation and severe land subsidence in the Taipei Basin. Declining water levels were gradually recovered back. Nowadays, high groundwater levels are developed in the Taipei Basin. This may cause safety problems such as seepage of underground facility, and liquefaction by the strong earthquake jeopardizing millions of people’s lives and properties in the metropolitan area of Taipei. To reduce the associated risks, the study aims to formulate a management strategy to rationally reduce the groundwater level declining trend and sustainable utilization of groundwater resources in the Taipei Basin. A hydrogeologic model of Taipei Basin using MODFLOW-96 was setup to evaluate water budget and safe yield of the aquifer. The simulated water budget indicates that the groundwater annual storage increases about 17 million cubic meters in the main (Jingmei) aquifer. The average groundwater safe yield of the Taipei Basin estimated by the Hill method is about 54 million cubic meters per year. Moreover, with consideration of the reduction of liquefaction risks the revised average safe yield is about 126 million cubic meters per year. To effectively use and manage groundwater resources, restriction order on the use of groundwater resources in the Taipei Basin need to be revised. The implementation of groundwater management index coupled with an upper limit of the average groundwater level set as −7.5 m below the surface for avoiding earthquake caused liquefaction is suggested to manage the groundwater level for safe-use of groundwater resources in the Taipei Basin.     

太行山前丘陵区基岩裂隙水赋存的非均一性和易疏干性特性

根据碧流河流域生态特征,分析了适合该流域的河道生态需水计算方法,应用于碧流河水库兴利调度,并以生态目标为基础,确定下游河道的生态需水量。结果表明:碧流河水库下游河道生态环境基本供水量及改善供水量分别需要2 765万m3和4 250万m3。为了保护和改善河流生态环境,促进流域水资源可持续利用,需要采取最严格的用水管理制度,加大非常规水源的开发利用力度,并结合调水工程以及河库连通工程等相关措施。     

建立在水动力关系基础上桃河阳泉段河道渗漏补给量的计算

阳泉市桃河上游河谷冲洪积层孔隙地下水，以其涌水量大、开采成本低成为当地的重要供水水源。其资源量除受河流径流量的大小影响外，更与河水与地下水的动力关系密切相关，本文根据两者间的水动力关系分为顶托渗漏和自由渗漏两个过程，并根据实测渗漏量计算出含水层参数，进而结合当地的水井工程布置情况，对河流渗漏量进行了计算。     

Groundwater Risk Assessment of the Third Aquifer in Tianjin City, China

More than 70 % of Tianjin city’s water supply comes from groundwater. As water demand increases, this reliance on groundwater has caused serious geological problems, such as seawater intrusion. The third aquifer is the main water supply aquifer for Tianjin city. According to supply conditions, water abundance, exploitation conditions, and water quality of the third aquifer, the type of ecological environment system, protection targets and requirements, the present situation of groundwater exploitation and utilization, the groundwater exploitation demand, and utilization for regional water resources allocation as well as national overall scheme about reasonable exploitation, utilization and protection of groundwater resource, groundwater in Tianjin has been divided into seven function areas. After analysis of influencing factors, like water abundance, exploitation intensity and well density, risk factors have been classified using AHP and GIS. Then the comprehensive evaluation model of groundwater exploitation and utilization risks was built. Using this model, the exploitation and utilization risks of the third aquifer in years 2015, 2020, and 2030 have been forecasted. The results show that the risk grade of this aquifer in 2015 is higher than now, while lower in 2020 and 2030. But the risk grade of the 3rd and 4th aquifer increases, since the water yield of this aquifer must still meet a certain amount to support the basic demand of this city.     

徐州城市供水水源地降落漏斗演变及成因分析

徐州市岩溶水强烈开采形成明显的水位降落漏斗,引发了岩溶地面塌陷、地裂缝、地下水污染等一系列环境地质问题。通过对水源地水位降落漏斗形成演化的分析,得出研究区水位漏斗演化的3个阶段:增采阶段-水位下降(20世纪80年代)、控采阶段-水位平稳(20世纪90年代)、压/禁采阶段-水位回升(2000年以来);地表水资源缺乏、城市生活及工业发展过度依赖岩溶水,城市化面积增大、有效入渗补给量减小,矿坑疏干排水、增大岩溶水排泄量等为水位降落漏斗形成演化的主要影响因素;通过对岩溶水开采量、年平均降水量、土地硬化面积与漏斗水位进行多元相关分析,得出岩溶水开采量为岩溶水水位持续下降及漏斗形成与演变的主导因素。提出岩溶水超采情况下的水资源保障对策:控采岩溶水,制定不同管理目标下的地下水水位控制红线;修建水库、植树造林,扩大岩溶水水源涵养区;利用采空区修建地下水库等,实现地表水、地下水、矿井水及城市雨水的优化分配。     

Current Practice and Future Challenges in Coastal Aquifer Management: Flux-Based and Trigger-Level Approaches with Application to an Australian Case Study

The control of groundwater abstraction from coastal aquifers is typically aimed at minimizing the risk of seawater intrusion, excessive storage depletion and adverse impacts on groundwater-dependent ecosystems. Published approaches to the operational management of groundwater abstraction from regulated coastal aquifers comprise elements of “trigger-level management” and “flux-based management”. Trigger-level management relies on measured groundwater levels, groundwater salinities and/or ecosystem health indicators, which are compared to objective values (trigger levels), thereby invoking management responses (e.g. pumping cut-backs). Flux-based management apportions groundwater abstraction rates based on estimates of aquifer recharge and discharge (including environmental water requirements). This paper offers a critical evaluation of coastal aquifer management paradigms using published coastal aquifer case studies combined with a simple evaluation of the Uley South coastal aquifer, South Australia. There is evidence that trigger-level management offers advantages over flux-based approaches through the evaluation of real-time resource conditions and trends, allowing for management responses aimed at protecting against water quality deterioration and excessive storage depletion. However, flux-based approaches are critical for planning purposes, and are required to predict aquifer responses to climatic and pumping stresses. A simplified modelling analysis of the Uley South basin responses to different management strategies demonstrates the advantages of considering a hybrid management approach that includes both trigger-level and flux-based controls. It is recommended that where possible, trigger-level and flux-based approaches be adopted conjunctively to minimize the risk of coastal groundwater degradation and to underpin strategies for future aquifer management and well-field operation.     

Quantitative Assessment of Regional Rock Aquifers, South-Western Quebec, Canada

The population of the St. Lawrence Lowlands platform in south-western Quebec, Canada, is heavily dependent on groundwater. The present study summarizes the quantity, quality and sustainability estimations of the groundwater resources found mainly in sedimentary rock aquifers. Results show that the regional groundwater flow in the considered domain of 1,500 km² is 97.7 Mm³/y with: 86.6% infiltration from precipitation, 9.6% inflow from neighboring aquifers, and 3.8% induced recharge. The regional sustainability is defined with simulated drawdowns from uniform withdrawal scenarios. The current withdrawal rate of 18 Mm³/y results in median drawdown of 0.6 m, compared to pre-development conditions. This drawdown is situated well in the sustainable range, an indication that regional aquifers are not overexploited. Hypothetical pumping rate of 24 Mm³/y resulting in an average drawdown of 2.2 m is estimated as sustainable limit. Increasing exploitation from 24 to 51 Mm³/y would need tight control and planning. Pumping rates beyond 51 Mm³/y are judged not sustainable as regional drawdowns become high, ∼8 m. The water levels in recharge areas are the most sensitive to groundwater extraction. Combining drawdown maps, groundwater quality zones, and aquifer vulnerability to surface contamination delineated the areas most suitable for future groundwater developments.     

Natural recharge to sustainable yield from the barind aquifer: a tool in preparing effective management plan of groundwater resources.

This paper presents the results of water balance study and aquifer simulation modeling for preliminary estimation of the recharge rate and sustainable yield for the semi arid Barind Tract region of Bangladesh. The outcomes of the study are likely to be useful for planning purposes. It is found from detailed water balance study for the area that natural recharge rates in the Barind Tract vary widely year to year. It may have resulted from the method used for the calculation. If the considered time interval had been smaller than the monthly rainfall, the results could have been different. Aquifer Simulation Modeling (ASM) for the Barind aquifer is used to estimate long-term sustainable yield of the groundwater considering limiting drawdown from the standpoint of economic pumping cost. In managing a groundwater basin efficiently and effectively, evaluation of the maximum annual groundwater yield of the basin that can be withdrawn and used without producing any undesirable effect is one of the most important issues. In investigating such recharge rate, introduction of certain terms such as sustainable yield and safe yield has been accompanied. Development of this area involves proper utilization of this vast land, which is possible only through ensured irrigation for agriculture. The Government of Bangladesh has a plan to develop irrigation facilities by optimum utilization of available ground and surface water. It is believed that the groundwater table is lowering rapidly and the whole region is in an acute state of deforestation. Indiscriminate groundwater development may accelerate deforestation trend. In this context estimation of actual natural recharge rate to the aquifer and determination of sustainable yield will assist in proper management and planning of environmentally viable abstraction schemes. It is revealed from the study that the sustainable yield of ground water (204 mm/y) is somewhat higher than the long-term annual average recharge (152.7 mm) to the groundwater reservoir. The reason behind this is that the rivers within and around the Barind Tract might have played the role of influent rivers.     

淮北采煤塌陷蓄水区地下水流场分布特征分析

为了解淮北采煤塌陷蓄水区地下水分布规律,在充分收集研究区已有相关成果资料的基础上,从研究采煤塌陷区域含水层结构变异入手,运用Visual Modflow软件对研究区地下水流场变化特征进行模拟、分析。结果表明：1）煤层完全开采情况下矿坑不再排水,因采煤矿坑排水而下降的松散层孔隙水水位在降雨补给和河流补给的作用下将逐渐回升,但基本无法恢复至采前水平;2）裂隙岩溶水接受塌陷区湖泊地表水和松散层孔隙水通过垂向网络型导水裂隙带不断入渗补给,导致研究区域裂隙岩溶水水位上升和溢出而形成多个局部水丘。闭坑后采煤塌陷蓄水区地下水流场分布规律研究成果可以为类似采煤塌陷蓄水区地下水资源综合利用提供参考。     

浅层地下水功能评价指标体系——以河南省平原岗区为例

河南省平原岗区因地下水开采出现了水位下降,严重超采地区形成局部降落漏斗,一些地区出现不同程度的地面沉降,咸水入侵淡水含水层以及地下水被污染。对此地区进行浅层地下水系统功能区划,自上而下构建了由系统层、功能层、属性层、指标层组成的评价指标体系,有19个评价指标。区划结果反映了研究区地下水功能状况。     

Artificial Neural Network Modeling for Groundwater Level Forecasting in a River Island of Eastern India

Forecasting of groundwater levels is very useful for planning integrated management of groundwater and surface water resources in a basin. In the present study, artificial neural network models have been developed for groundwater level forecasting in a river island of tropical humid region, eastern India. ANN modeling was carried out to predict groundwater levels 1 week ahead at 18 sites over the study area. The inputs to the ANN models consisted of weekly rainfall, pan evaporation, river stage, water level in the drain, pumping rate and groundwater level in the previous week, which led to 40 input nodes and 18 output nodes. Three different ANN training algorithms, viz., gradient descent with momentum and adaptive learning rate backpropagation (GDX) algorithm, Levenberg–Marquardt (LM) algorithm and Bayesian regularization (BR) algorithm were employed and their performance was evaluated. As the neural network became very large with 40 input nodes and 18 output nodes, the LM and BR algorithms took too much time to complete a single iteration. Consequently, the study area was divided into three clusters and the performance evaluation of the three ANN training algorithms was done separately for all the clusters. The performance of all the three ANN training algorithms in predicting groundwater levels over the study area was found to be almost equally good. However, the performance of the BR algorithm was found slightly superior to that of the GDX and LM algorithms. The ANN model trained with BR algorithm was further used for predicting groundwater levels 2, 3 and 4 weeks ahead in the tubewells of one cluster using the same inputs. It was found that though the accuracy of predicted groundwater levels generally decreases with an increase in the lead time, the predicted groundwater levels are reasonable for the larger lead times as well.     

Hydrologic and Hydrogeologic Characterization of a Deltaic Aquifer System in Orissa, Eastern India

The present study focuses on the in-depth hydrologic and hydrogeologic analyses of Kathajodi-Surua Inter-basin within the Mahanadi deltaic system of Orissa, eastern India to explore the possibility of enhanced and sustainable groundwater supply. The results of 6 years (2001–2006) streamflow analysis indicated that the river flow is highly seasonal and it reduces to almost no flow during summer seasons. Land use map of the study area for the monsoon (Kharif) and post-monsoon (Rabi) seasons was developed by remote sensing technique and runoff estimation was done by curve number method. The runoff estimated for the 20-year period (1990–2009) varied from a minimum of 10.2% of the total monsoon rainfall in 1995 to a maximum of 43.3% in 2003. The stratigraphy analysis indicated that a leaky confined aquifer comprising medium to coarse sand exists at depths of 15 to 50 m and has a thickness of 20 to 55 m. The analysis of pumping test data at 9 sites by Aquifer-Test software indicated that the aquifer hydraulic conductivity ranges from 11.3 to 96.8 m/day, suggesting significant aquifer heterogeneity. Overall groundwater flow is from north-west to south-east direction. There is a 5 to 6 m temporal variation and 3 to 4 m spatial variation of groundwater levels over the basin. The rainfall-groundwater dynamics and stream-aquifer interaction in the river basin were studied by correlation analysis of groundwater level with weekly rainfall and river stage. The correlation between the weekly rainfall and weekly groundwater level was found to vary from ‘poor’ to ‘fair’ (r = 0.333 to 0.659). In contrast, the weekly groundwater level was found to be strongly correlated with the weekly river stage (r = 0.686 to 0.891). The groundwater quality was found suitable for both irrigation and drinking purposes. It is recommended that a simulation-cum-optimization modeling following an integrated approach is essential for efficient utilization of groundwater resources in the study area.     

基于EMD-LSTM耦合模型的趵突泉岩溶地下水水位预测应用

由于岩溶地下水具有强烈的非线性及非平稳波动特征,水位预测结果容易产生较大误差。针对岩溶地下水水位预测精度较差的问题,提出一种EMD-LSTM耦合模型,首先采用经验模态分解（EMD）将趵突泉岩溶地下水水位分解为5个分量（4个本征模函数项和1个残余项）,以此消除水位数据的非平稳波动性;同时构建长短期记忆（LSTM）神经网络模型,并将与地下水水位动态变化密切相关的降水量（表征含水层补给项）和月平均气温值、月最高气温值、月最低气温值、水汽压值（表征含水层排泄项）作为输入项分别对5个分量进行预测,最终将分量预测结果累加获得地下水水位预测值。结果表明：EMD能够显著消除岩溶地下水水位的非平稳波动特征;EMD-LSTM耦合模型可有效提高岩溶地下水水位的预测精度,其均方根误差相比于LSTM神经网络模型、ARIMA模型分别减小了27.86%和59.94%。总体来说,本文所提出的EMD-LSTM耦合模型具有较强的可靠性和稳定性,可为岩溶地下水水位的精确预测提供借鉴。