煤矿开采导水裂隙带发育对潜水水位影响研究

为定量阐述采煤导水裂隙带发育对潜水含水层的影响,在分析采煤导水裂隙带发育形成机理的基础上,依据采煤导水裂隙带发育对潜水含水层的影响进行分类研究,按照对潜水水位影响的程度分为两类模式。基于这两种分类模式,以锦界矿区为研究对象,建立考虑导水裂隙带发育的地下水数值模拟模型,利用大量实测水位反演出导水裂隙带影响下各分区垂向渗透系数值变化序列,以此反映导水裂隙带发育对潜水含水层的影响。通过构建的地下水数值模型计算表明,在分类模式二条件下,由于导水裂隙带导通潜水关键隔水层构成垂向渗漏通道,隔水层垂向渗透系数显著增大,潜水水位形成大范围地下水降落漏斗。开采前10年最大降深值28 m,降深大于20 m的影响严重区域面积约为2.56 km~2,开采后20年,潜水位最大降深达到32 m。     

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.     

Modeling Groundwater Flow and Seawater Intrusion in the Coastal Aquifer of Wadi Ham,UAE

Groundwater pumping from Kalbha and Fujairah coastal aquifer of the United Arab Emirates (UAE) has increased significantly during the last two decades to meet the agriculture water demands. Due to the lack of natural replenishment from rainfall and the excessive pumping, groundwater levels have declined significantly causing an intrusion of seawater in the coastal aquifer of Wadi Ham. As a result, many pumping wells in the coastal zone have been terminated and a number of farms have been abandoned. In this paper, MODFLOW was used to simulate the groundwater flow and assess the seawater intrusion in the coastal aquifer of Wadi Ham. The model was calibrated against a five-year dataset of historical groundwater levels and validated against another eleven-year dataset. The effects of pumping on groundwater levels and seawater intrusion were investigated. Results showed that reducing the pumping from Khalbha well field will help to reduce the seawater intrusion into the southeastern part of the aquifer. Under the current groundwater pumping rates, the seawater will continue to migrate inland.     

Analysis and Assessment of Hydrochemical Characteristics of Maragheh-Bonab Plain Aquifer,Northwest of Iran

The present study aims at assessing the hydrochemistry of the groundwater system of the Maragheh-Bonab Plain located in the East Azarbaijan Province, northwest of Iran. The groundwater is used mainly for drinking, agriculture and industry. The study also discusses the issue of the industrial untreated wastewater discharge to the Plain aquifer that is a high Ca-Cl water type with TDS value of about 150 g/L. The hydrogeochemical study is conducted by collecting and analyzing the groundwater samples from July and September of 2013. The studied system contains three major groundwater types, namely Ca–Mg–HCO₃, Na–Cl, and non-dominant water, based on the analysis of the major ions. The main processes contributing to chemical compositions in the groundwater are the dissolution along the flow path, dedolomitisation, ion exchange reactions, and the mixing with wastewater. According to the computed water quality index (WQI) ranging from 25.45 to 194.35, the groundwater in the plain can be categorized into “excellent water”, “good water”, and “poor water”. There is a resemblance between the spatial distribution of the WQI and hydrochemical water types in the Piper diagram. The “excellent” quality water broadly coincides with the Ca-Mg-HCO₃ water type. The “poor” water matches with the Na–Cl water type, and the “good” quality water coincides with blended water. The results indicate that this aquifer suffers from intense human activities which are forcing the aquifer into a critical condition.     

基于GMS的云南德厚水库下游废弃砒霜厂地下水溶质运移模拟

地下水溶质运移模拟是找出污染物迁移规律、确定污染范围及污染物浓度分布的重要手段,可以为合理开发地下水资源、优化设计地下水开采方案及地下水污染修复提供定量依据。在分析德厚水库咪哩河流域裂隙岩溶含水层的水力性质和污染物运移特征的基础上,运用GMS软件建立地下水流场模型和溶质运移模型,对裂隙岩溶水的流场和污染物进行了数值研究,判断出了污染源分布及污染羽扩展范围,分析了砒霜厂污染物运移对水库建设的影响。     

Groundwater Resources and Human Impacts in a Quaternary Intramontane Basin (L'Aquila Plain,Central Italy)

Abstract

An aquifer vulnerability study was carried out in the L'Aquila Plain of Central Italy for evaluating changes in groundwater quantity and quality induced by human activities. The L'Aquila Plain, filled with Quaternary clastic deposits, is an intramontane basin encircled by karst massifs characterized by regional groundwater, which is connected with the porous multilayer aquifer of L'Aquila Plain. The study was organized into different steps: (1) geo-lithological characterization; (2) sampling of hydrogeological data and water budget evaluation; and (3) hydrochemical and microbiological monitoring of springs and wells. The latter step made it possible to identify water-rock interaction, groundwater mixing and recharge, and to recognize the different sources of groundwater pollution. The plain aquifer, mainly recharged by the surrounding carbonate massifs, shows centripetal groundwater flowpaths. The hydrochemical features show two groundwater end-members, coming from carbonate aquifers or circulating only in the plain, with intermediate mixed groundwater. The observed ground-water pollution is negligible, but it will probably increase if the strong development of the human activities continues without groundwater protection planning.     

A GIS-based DRASTIC Model for Assessing Aquifer Vulnerability in Kherran Plain, Khuzestan, Iran

The Kherran plain is located in the northeast of Ahwaz in Khuzestan Province, Iran. The state of groundwater pollution is a critical issue with increasing population and agricultural development in Iran. For this reason, vulnerability assessment is an important factor in any policy making decision in any part of country. Focusing on this issue, the article attempts to presents a groundwater vulnerability map for the Kherran plain. The map designed to show areas of highest potential for groundwater pollution based on hydro-geological condition and human impacts. Seven major hydro-geological factors (Depth to water table, net Recharge, Aquifer media, Soil media, Topography, Impact of vadose zone and hydraulic Conductivity) were incorporated into DRASTIC model and geographical information system (GIS) was used to create a groundwater vulnerability map by overlaying the available hydro-geological data. The output map shows that the west and southwest of the aquifer are under medium vulnerability while small areas on northwest and east of the study area have no risk to pollution. Other parts of aquifer have low vulnerability. For testing of the vulnerability assessment, 27 groundwater samples were collected from the different vulnerability zones of the study area. The chemical analysis results show that the southwest and west parts of aquifer (moderate vulnerability zones) have higher nitrate concentration relative to the rest of aquifer, that are located in low vulnerability zone.     

A Suitable Tool for Sustainable Groundwater Management

Artificial recharge is used to increase the availability of groundwater storage and reduce saltwater intrusion in coastal aquifers, where pumping and droughts have severely impaired groundwater quality. The implementation of optimal recharge methods requires knowledge of physical, chemical, and biological phenomena involving water and wastewater filtration in the subsoil, together with engineering aspects related to plant design and maintenance operations. This study uses a novel Decision Support System (DSS), which includes soil aquifer treatment (SAT) evaluation, to design an artificial recharge plant. The DSS helps users make strategic decisions on selecting the most appropriate recharge methods and water treatment technologies at specific sites. This will enable the recovery of safe water using managed aquifer recharge (MAR) practices, and result in reduced recharge costs. The DSS was built using an artificial intelligence technique and knowledge-based technology, related to both quantitative and qualitative aspects of water supply for artificial recharge. The DSS software was implemented using rules based on the cumulative experience of wastewater treatment plant engineers and groundwater modeling. Appropriate model flow simulations were performed in porous and fractured coastal aquifers to evaluate the suitability of this technique for enhancing the integrated water resources management approach. Results obtained from the AQUASTRESS integrated project and DRINKADRIA IPA CBC suggest the most effective strategies for wastewater treatments prior to recharge at specific sites.     

陡河流域地表水与地下水转化关系

通过对陡河流域地表水-地下水水样的氢氧同位素分布特征进行分析,发现研究区河岸带第Ⅰ含水层除了受大气降水、灌溉回归水入渗补给外,还接受河水早期的渗漏补给,第Ⅱ含水层对第Ⅲ含水层有越流补给,第Ⅱ含水层同时也受大气降水和灌溉回归水的影响,而远离河岸带的第Ⅳ含水层与上覆各含水层稳定同位素组成显著不同,河岸带水库附近的第Ⅳ含水层可能受地表水库渗漏影响。河岸带地下水与地表水水力联系的变迁严格受河岸带地下水水位变化控制,如景庄子剖面的地下水埋深为5m,雨季时河水补给地下水,旱季时地下水补给河水,而靠近地下水漏斗中心的越河乡剖面地下水水位埋深达25m,其常年受地表水补给。     

Groundwater Quality Zonation Assessment using GIS, EOFs and Hierarchical Clustering

Three methods are utilized in this paper to assist in the groundwater clustering, in an arid region aquifer, into similar zones according to its quality. A multiple regression is first applied in order to assess the importance of the different chemical constituents in the amount of total dissolved salt, which shows the dominance of chlorine and sodium. A multivariate analysis based on empirical orthogonal functions and hierarchical clustering (EOFs) is applied to assist in water quality clustering in the studied aquifer. The clustering has produced five distinguished categories of groundwater quality, which agree well with World Health Organisation criteria and limits for water usage. Based on these categories, spatial distribution maps of groundwater quality are produced by Kriging and GIS software.     

Brackish groundwater resources in Bahrain: Current exploitation,numerical evaluation and prospect for utilization

In Bahrain, where water resources available for direct use are finite and the best of its quality has a salinity of over 2.5 g L^–1, utilization of brackish groundwater is an essential part in the management of the country's water resources. Bahrain's brackish water occurs in the Rus-Umm Er Radhuma formations in the form of a lens of a finite lateral extent, with a salinity ranges between 8 and 15 g L^–1. Planning for utilization of brackish groundwater for desalination purposes in Bahrain was based on simulation modeling of the aquifer system using a mixing cell model developed originally in 1983. The model was used to predict the aquifer response to pumping from the proposed wellfield in terms of changes of TDS over a period of 20 years. Construction and operation of the wellfield in 1984 was based on the predicted salinity changes. Over the past 9 uears of wellfield operation (1984–1993), and through continuous monitoring of the aquifer response to pumping, the collected data is used to post-audit the original model by history matching. The calibration process adopted has resulted in a statisfactory agreement between the model output and the observed data. The model is then used to predict the wellfield salinity changes and the aquifer potentiometric levels. The expected life span for the brackish groundwater utilization by the wellfield is redefined through constrained utilization that takes into account salinity deterioration coupled with the effect of head decline on hydraulic interaction between the brackish water and the upper fresh water aquifer. The results suggest that the operation of the wellfield should cease by the year 2007. Construction of a new model that enables testing and evaluating different development scenarios is recommended to aid future management decisions regarding the utilization of brackish groundwater.     

潮汐波动对秦山三期核电工程场地裂隙含水层的影响

杭州湾潮汐的波动在临近的含水层中产生的压力波，由于压力波向内地传播，使地下水位和水力坡度连续不断地发生波动，并直接影响场地周围含水层中压力表的读数。为了掌握潮汐对场地地下水的影响，通过比较地下水和地表水平均水位标高计算地下水的平均水力坡度。压力波按正弦波传播，地下水相对于潮水有一时间滞后，本文中计算了不同观测地点的滞后时间，影响因子和波长，为核电站的建设提供了重要的依据。     

Cryptosporidium spp. and Giardia spp. removal by bank filtration at Beberibe River,Brazil

In bank filtration (BF) technology, a production well is pumped near surface water and induces water flow from the river through a porous medium to the well by percolation into the soil. Several physical, chemical, and biological processes occur, providing a natural water treatment along the river banks. An experimental area was installed on the Beberibe River with 2 production wells and 7 monitoring wells. The BF potential in removing pathogenic intestinal parasites and analysis of physical–chemical and bacteriological parameters was evaluated, according to Standard Methods. River–aquifer interaction was characterized by piezometric levels of production wells. Monitoring of the wells was correlated with the water depth of the river and precipitation. Parasite analysis was performed using Hoffman, Pons, and Janer's methods of spontaneous sedimentation, followed by centrifugation and preparation of slides stained with acetic Lugol. Protozoa oocysts were isolated by a modified Ziehl‐Neelsen method, preceded by sedimentation and centrifugation. The pathogenic protozoa found in samples from Beberibe River were Cryptosporidium spp., Giardia spp., Entamoeba histolytica/dispar complex, and Isospora belli. Pathogenic helminths were also detected: Ascaris lumbricoides, Strongyloides stercoralis, and hookworm eggs and larvae, Hymenolepis nana. In water samples from the production wells, no waterborne pathogens were found. The BF pilot project was effective in reducing levels of turbidity and color. Total coliforms and Escherichia coli were absent in the production wells. Piezometric levels of production wells and monitoring wells correlated with water depth of Beberibe River show hydraulic connection between the production wells and river, thus featuring a river–aquifer interaction. The BF pilot system showed potential for reduction or elimination of pathogenic intestinal parasites.     

GIS-Based Assessment for the Development of a Groundwater Quality Index Towards Sustainable Aquifer Management

This study aims at developing Groundwater Quality Indices (GQIs) that constitute a reliable tool in defining aquifer vulnerability. For this purpose, water quality sampling campaigns were conducted on 60 groundwater wells during most vulnerable periods of early and late summer to ensure the representativeness of the targeted GQI under worst case conditions. The samples were tested for various water quality indicators, which were then used to develop the GQIs through GIS-based mapping with spatial geostatistical analysis. The results contribute in filling a gap in GQI definition and form a basis for planning effective water quality management towards sustainable exploitation of groundwater resources particularly during summer periods when recharge is limited.     

Predictive Simulation of Flow and Solute Transport for Managing the Salalah Coastal Aquifer, Oman

A three-dimensional numerical model for flow and solute transport was used for the management of the Salalah aquifer. The model calibration procedures consisted of calibrating the aquifer system hydraulic parameters by history matching under steady and transient conditions. The history of input and output of the aquifer were reconstructed in a transient calibration from 1993 to 2005. Predictive simulation of the aquifer was carried out under transient conditions to predict the future demand of groundwater supply for the next 15 years. A baseline scenario was worked out to obtain the piezometric surface and salinity distribution for the “business as usual” conditions of the aquifer. The “business as usual” scenario was predicted and simulated for the period 2006 until 2020. The effectiveness of seven management options was proposed and assessed for comparison with the “business as usual” conditions. The established simulation model was used to predict the distribution of the piezometric surface, salinity distribution, and mass balance under the proposed scenarios for the prediction period 2006–2020. The scenarios were: (1) relocate Garziz and MAF farms far from the freshwater zone, (2) suspend the abstraction of grass production for 4 months a year, (3) changes in agricultural and irrigation system patterns, (4) establish a desalination plant, (5) combined scenario (1 + 4), (6) combined scenario (1 + 3), and (7) combining all scenarios (1 + 2 + 3 + 4). The result of the simulation shows that the best effective option in terms of aquifer groundwater levels is the fifth proposed scenario and the sixth proposed scenario is the best effective option in terms of aquifer groundwater salinity situation during the next 15 years. This project suggested the application of scenario 6 as it is environmentally sound in terms of sustainable management. A prediction has been made which shows that further actions have to be taken within the next two decades to ensure continuity of the municipal water supply. The management scenarios are examined in the case of the Salalah coastal aquifer using groundwater simulation, which can also be applied to other regions with similar conditions. The established model is considered a reasonable representation of the physical conditions of the Salalah plain aquifer, and can be used as a tool by the water and environmental authorities in the management of the groundwater in the region.     

西南典型岩溶区地下水防污性评价方法

与第四系含水层相比,西南岩溶区常缺少天然的防渗或过滤层,岩溶含水层的地下水防污能力较差,地表水和污染物很容易通过落水洞等岩溶形态直接进入含水层或地下河。现以典型岩溶区———桂林市区为例,在将该地区依据地貌分为7个亚区的基础上,结合岩溶水二元补给特性,尝试运用"二元法"对桂林市岩溶区地下水的防污能力进行分区评价,评价结果显示,桂林市区除洪积扇亚区一带地下水的防污能力强以外,其他地区的岩溶地下水都面临着防污能力差的问题,尤其是在落水洞发育的峰丛洼地、峰丛谷地两个亚区,如果不加以保护,地下水极易被污染。通过与前人成果的对比,该方法将径流特征作为一个主要的评价因子,所得结果更为合理,而且本方法具有所需数据量少,可以进行定性评价等优点,可在我国西南岩溶区中加以推广。     

Groundwater Exploration and Assessment in Rural Communities of Yobe State, Northern Nigeria

The provision of adequate water supply and sanitation to the rapidly growing urban populations is increasingly becoming a problem for governments throughout the world. The continuing expansion of the numbers of people in cities who need water and sanitation services form a continuous pressure to either invest in additional production capacity or to stretch the available supplies to serve more people. Due to rapid increase in population growth in the Yobe State north of Nigeria, there is a shortage in the water supply to Damaturu city the capital of the state and surrounding villages. At the present the total water supply is about 10,000 m³/day abstracted form the shallow alluvial groundwater aquifer using 29 production wells. Due to the expected increase in water demand and the limited potentiality of shallow aquifer system, other deep aquifers were explored and investigated to evaluate their potentiality for future water demand. Vertical Electrical Sounding Method was used for the geophysical survey of the study area. Groundwater flow model was developed and calibrated against the historical information. Three wellfields were designed to provide Damaturu city and surrounding villages with the required water. The calibrated model has been used to evaluate the aquifer potentiality and the effect of future withdrawals on the deep aquifer system. It was found that the aquifer system within the study area consists of two main layers. The upper layer is the Chad formation comprises an alluvial sand and gravel with intercalation of thin sility clay layers. The second layer is Keri-Keri formation consists of sandstone formation which is not explored before. During this study the Kerri-Kerri aquifer system was investigated as an alternative source for groundwater for future demand. The study presents an integrated groundwater resources management strategy for present and future water supply for rural communities.     

The Effects of Groundwater and Surface Water Use on Total Water Availability and Implications for Water Management: The Case of Lake Naivasha, Kenya

This study discusses the effects of water abstractions from two alternative sources on the available water volume around Lake Naivasha, Kenya: the lake itself and a connected aquifer. An estimation of the water abstraction pattern for the period 1999–2010 is made and its effect on the available water volume in Lake Naivasha and its connected aquifer is evaluated using a simple water balance modeling approach. This study shows that accurate estimates of annual volume changes of Lake Naivasha can be made using a simple monthly water balance approach that takes into account the exchange of water between the lake and its connected aquifer. The amount of water that is used for irrigation in the area around Lake Naivasha has a substantial adverse effect on the availability of water. Simulation results of our simple water balance model suggests that abstractions from groundwater affect the lake volume less than direct abstractions from the lake. Groundwater volumes, in contrast, are much more affected by groundwater abstractions and therefore lead to much lower groundwater levels. Moreover, when groundwater is used instead of surface water, evaporation losses from the lake are potentially higher due to a larger lake surface area. If that would be the case then the overall water availability in the area is more strongly affected by the abstraction of groundwater than by the abstraction of surface water. Therefore water managers should be cautious when using lake levels as the only indicator of water availability for restricting water abstractions.     

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.     

变化环境对华北平原地下水可持续利用的影响研究

针对华北平原地下水利用中存在的问题,采用分布式水文MIKE SHE模型,考虑人类活动（农业节水措施和南水北调工程）和气候变化等变化环境的影响,通过设定4大类情景（每类情景中均设定了3类气候变化子情景）模拟了2019-2028年华北平原地下水的利用状况。结果表明：农业节水措施和南水北调工程等人类活动对华北平原地下水水位、水均衡和含水层储量有较大的影响;相对于现状保持型情景(SQM),模拟期末(2028年12月31日)农业节水型情景(AWS)、南水北调工程供水型情景(SNWDP)和综合利用型情景(CU)下华北平原饱和含水层储量分别增加0.168、0.558和1.433 m;气候变化对华北平原地下水的影响量级与人类活动的影响相当,且地下水水位、水均衡和含水层储量变化的方向和大小均与未来气候条件的干湿程度呈正相关关系,到模拟期末,相对于现状保持型情景(SQM),湿润、正常和干旱的气候情景下华北平原饱和含水层储量分别为增加0.972~2.239 m、增加0.119~1.540 m和减少0.372~0.940 m;只有综合考虑各种引水和节水措施,多管齐下,才能保证华北平原地下水的可持续利用。