A GIS enabled nested simulation-optimization model for routing groundwater to overcome spatio-temporal water supply and demand disconnects in South Texas

Groundwater, under sustainable management policies, can be an invaluable source of water to municipal, agricultural, and industrial sectors. Management, however, can be challenging given that historically, these resources have been privately owned and minimally regulated. This research details the development of a decision support system (DSS) which couples a GIS-based multi-criteria decision-making (MCDM) scheme with simulation-optimization routines to identify suitable regions for groundwater development and optimal preferences for apportioning those supplies to areas of demand in South Texas. The developed DSS consisted of three modules: (1) a GIS-based MCDM for identifying suitable locations for groundwater production; (2) a simulation-optimization model for estimating available groundwater; and (3) a transportation optimization model for redistributing the groundwater. Applying a comprehensive suite of nine exclusionary criteria in GIS resulted in only 15,304 km² (5,909 mi²) suitable for groundwater production out of the original ~50,500 km² (19,500 mi²). Two ideal sites were selected in the suitable region based on proposed major water supply projects in the study area. The projected groundwater extraction rates per month varied considerably over a year emphasizing a need for storage technologies. Furthermore, a transportation optimization model, which considered cost of storage and movement, was developed and applied to obtain the most optimal scheme to transport groundwater from potential supply centers located in Bee and Kennedy counties to projected water deficit areas of San Antonio, Laredo, and McAllen, TX, USA. Lastly, a full-factorial sensitivity analysis was carried out to check the impacts of the supply and demand factors on groundwater production and transport. Policies at the supply centers had a larger impact on the total availability of water, and policies at the demand centers had a larger impact on the total cost of the management scheme. Furthermore, an analysis of total volume stored in a storage and recovery system exhibited an inverse relationship with the groundwater development (supply side) policies and a direct relationship with the demand requirements. The developed DSS proved useful for determining the most optimal siting and distribution network for groundwater sources in South Texas.     

Subsurface dams to harvest rainwater— a case study of the Swarnamukhi River basin, Southern India

Declining water level trends and yields of wells, deterioration of groundwater quality and drying up of shallow wells are common in many parts of India. This is mainly attributed to the recurrence of drought years, over exploitation of groundwater, increase in the number of groundwater structures and explosion of population. In this subcontinent, the saving of water has to be done on the days it rains. India receives much of its rainfall in just 100 h in a year mostly during the monsoon period. If this water is not captured or stored, the rest of the year experiences a precarious situation manifest in water scarcity. The main objective behind the construction of subsurface dams in the Swarnamukhi River basin was to harvest the base flow infiltrating into sandy alluvium as waste to the sea and thereby to increase groundwater potential for meeting future water demands. An analysis of hydrographs of piezometers of four subsurface dams, monitored during October 2001–December 2002, reveals that there is an average rise of 1.44 m in post-monsoon and 1.80 m in the pre-monsoon period after the subsurface dams were constructed. Further, during the pre-monsoon month of June, much before construction of subsurface dams in October 2001, the water level was found fluctuating in the range of 3.1–10 m, in contrast to the fluctuation ranging from 0.4 to 3.1 m during the period following the construction of dams. Hence, the planning of rainwater harvesting structures entails thorough scientific investigations for identifying the most suitable locations for subsurface dams.     

GIS-based subsurface databases and 3-D geological modeling as a tool for the set up of hydrogeological framework: Nabeul–Hammamet coastal aquifer case study (Northeast Tunisia)

The subsurface data are a basic requirement for the set up of hydrogeological framework. Geographic information systems (GIS) tools have proved their usefulness in hydrogeology over the years which allow for management, synthesis, and analysis of a great variety of subsurface data. However, standard multi-layered systems are quite limited for modeling, visualizing, and editing subsurface data and geologic objects and their attributes. This paper presents a methodology to support the implementation of hydrogeological framework of the multi-layered aquifer system in Nabeul–Hammamet (NH) coastal region (NE, Tunisia). The methodology consists of (1) the development of a complete and generally accepted hydrogeological classification system for NH aquifer system (2) the development of relational databases and subsequent GIS-based on geological, geophysical and hydrogeological data, and (3) the development of meaningful three-dimensional geological and aquifer models, using GIS subsurface software, RockWorks 2002. The generated 3-D geological models define the lithostratigraphy and the geometry of each depositional formation of the region and delineate major aquifers and aquitards. Where results of the lithologic model revealed that there is a wide range of hydraulic conductivities in the modeled area, which vary spatially and control the groundwater flow regime. As well, 17 texturally distinct stratigraphic units were identified and visualized in the stratigraphic model, while the developed aquifer model indicates that the NH aquifer system is composed of multi-reservoir aquifers subdivided in aquifers units and separated by sandy clay aquitards. Finally, this study provides information on the storing, management and modeling of subsurface spatial database. GIS has become a useful tool for hydrogeological conceptualization and groundwater management purposes and will provide necessary input databases within different groundwater numerical models.     

Urbanization and the groundwater budget, metropolitan Seoul area, Korea

The city of Seoul is home to more than 10 million people in an area of 605 km². Groundwater is abstracted for public water supply and industrial use, and to drain underground facilities and construction sites. Though most tap water is supplied from the Han River, the quantity and quality of groundwater is of great concern to Seoul's citizens, because the use of groundwater for drinking water is continuously increasing. This study identifies the major factors affecting the urban water budget and quality of groundwater in the Seoul area and estimates the urban water budget. These factors include leakage from the municipal water-supply system and sewer systems, precipitation infiltration, water-level fluctuations of the Han River, the subway pumping system, and domestic pumping. The balance between groundwater recharge and discharge is near equilibrium. However, the quality of groundwater and ability to control contaminant fluxes are impeded by sewage infiltration, abandoned landfills, waste dumps, and abandoned wells. Electronic Publication     

“水文地质与水资源调查计划”进展

为服务生态文明建设和自然资源管理,促进山水林田湖草沙生命共同体健康协调,中国地质调查局组织开展以流域为单元的全国水文地质与水资源调查,重点部署了国家地下水监测工程运行维护、全国地下水位统测、全国地下水资源评价、重点地区水平衡研究、水文地质与水资源智慧服务系统建设、服务脱贫攻坚与乡村振兴等工作任务。2019年以来主要取得七方面进展,包括研究编制了基于生态优先理念涵盖大气水、地表水、地下水、海洋水的《地质调查支撑服务水资源管理总体设计》,引领了地质调查转型发展;高效运行国家地下水监测工程,数据对外实现全面共享服务,有力支撑了自然资源、水利、生态环境和科研等领域地下水管理与研究研究;建立了较完善的全国地下水位统测网络,统测点达5.6万个,准确掌握区域地下水流场年度变化;建立了全国地下水年度调查监测评价工作机制,实现地下水资源量、储存量及变化量年度出数;探索开展海河流域等重点地区水平衡研究,掌握了区域水平衡状况、人类活动影响下的水资源变化过程及其互馈机制;搭建全国水文地质与水资源智慧服务平台,初步建立多要素的全国水文地质与水资源数据库,研发了地下水资源在线评价系统;高质量完成扶贫找水任务,有力支撑服务了脱贫攻坚与乡村振兴。     

Site selection for drinking-water pumping boreholes using a fuzzy spatial decision support system in the Korinthia prefecture,SE Greece

The implementation of a geographic information system (GIS)/fuzzy spatial decision support system in the selection of sites for drinking-water pumping boreholes is described. Groundwater is the main source of domestic supply and irrigation in Korinthia prefecture, south-eastern Greece. Water demand has increased considerably over the last 30 years and is mainly met by groundwater abstracted via numerous wells and boreholes. The definition of the most “suitable” site for the drilling of new boreholes is a major issue in this area. A method of allocating suitable locations has been developed based on multicriteria analysis and fuzzy logic. Twelve parameters were finally involved in the model, prearranged into three categories: borehole yield, groundwater quality, and economic and technical constraints. GIS was used to create a classification map of the research area, based on the suitability of each point for the placement of new borehole fields. The coastal part of the study area is completely unsuitable, whereas high values of suitability are recorded in the south-western part. The study demonstrated that the method of multicriteria analysis in combination with fuzzy logic is a useful tool for selecting the best sites for new borehole drilling on a regional scale. The results could be used by local authorities and decision-makers for integrated groundwater resources management.     

乌鲁木齐河流域柴窝堡盆地与河谷区地下水流模拟

乌鲁木齐河流域柴窝堡盆地与河谷区是乌鲁木齐市的重要供水水源地。为了更好地为地下水资源的可持续开发提供依据,本文尝试将几何形状及含水层厚度差异悬殊的柴窝堡盆地与河谷区联合起来,运用GMS模型系统建立了区域地下水稳定流和非稳定流数值模型。通过对观测孔地下水位过程线和地下水流场进行拟合,校正了研究区的渗透系数、给水度和储水率等水文地质参数。并运用模型分析了研究区的地下水流系统、地下水均衡量、地下水位变化趋势及地下水位监测网的设计。结果表明研究区地下水流主要存在两个径流排泄区:沿乌鲁木齐主河道的径流排泄区和以柴窝堡湖和大小盐湖为排泄中心的径流区;地下水储存量相对较大,能够调节季节性变化与地下水开采的影响;应加强主要河流洪积扇补给区和山前侧向补给带地下水位的监测与排泄区泉水流量的观测。     

Integrated approach of geospatial visualization and modeling for groundwater management in hard rock terrains in Nagpur Urban Area,India

Groundwater management requires complete visualization of aquifer characteristics to understand scientific aspects and hence remains a challenge, especially in hard rock terrains. In the present research paper, a comprehensive approach using 3D stratigraphic model, fence diagrams and numerical modeling has been proposed to understand the groundwater status for effective recharge. The stratigraphy, groundwater flow, and groundwater fluctuations for the period 1999–2010 were analyzed. The total volume of formations, volume of voids, storage capacity, and quantities of recharge of unconfined aquifer system in the Nagpur urban area were estimated. The steady state groundwater flow model of Basalt formation was calibrated to evaluate the subsurface system using Processing Modflow (PMWIN 5.3.2). The calibrated hydraulic head is compared with field observed head. The comparative spatial analysis presents a simple integrated approach in identifying zones with falling groundwater trends suitable for groundwater recharge in hard rock terrain in Nagpur urban area.     

Groundwater management in northern Iraq

Groundwater is vital and the sole resource in most of the studied region of northern Iraq. It has a significant role in agriculture, water supply and health, and the elimination of poverty in rural areas. Although Iraq is currently dramatically disturbed by complex political and socio-economic problems, in its northern part, i.e. the Kurdish-inhabited region, fast urbanization and economic expansion are visible everywhere. Monitoring and water management schemes are necessary to prevent aquifer over-exploitation in the region. Artificial recharge with temporary runoff water, construction of subsurface dams and several other aquifer management and regulation measures have been designed, and some implemented, in order to improve the water situation. Recommendations, presented to the local professionals and decision-makers in water management, include creation of Water Master Plans and Water User Associations, synchronization of drilling programmes, rehabilitation of the existing well fields, opening of new well fields, and the incorporation of new spring intakes in some areas with large groundwater reserves, as well as construction of numerous small-scale schemes for initial in situ water treatment where saline groundwater is present.     

河北省秦皇岛市海水入侵地质灾害及其防治措施

随着秦皇岛地区人口增加、经济发展,地下水的开采日益加大,沿海地区由此产生的海水入侵现象较为普遍。海水入侵也是一种地质灾害,如何防止海水入侵是广大地质工作者和相关科技人员所要解决的问题。本文在分析了本地区海水入侵分布规律、发生原因及产生机理的基础上,提出科学管理地下水开采、引调客水补充地下水以及修建拦潮坝等多种举措防治海水入侵。借鉴国内外成熟的经验和方法,修建拦水坝拦潮蓄洪是治理海水入侵行之有效的方法。同时指出,修建梯级多道拦水坝逐级提高河水位强化对地下水的补给是治理海水入侵的一种新的尝试。     

AHP在地下水防污性能评价中的应用-以江苏浅层孔隙地下水为例

地下水的防污性能评价是地下水环保工作的基础,其结果能为地下水环境保护、饮水安全保障体系建设等提供科学依据。针对传统DRASTIC评价模型存在的不足,结合江苏省浅层孔隙含水层的水文地质条件。提出基于层次分析法（AHP）的DRAVT防污性能评价模型,利用GIS空间分析功能进行地下水防污性能评价．该模型的评价结果客观科学,能有效的为规划部门及地下水资源管理部门服务。     

基于数值模型的地下水污染预警方法研究

地下水是中国许多城市主要的供水水源,目前中国部分城市地下水已受到不同程度的污染,导致地下水资源供需矛盾日益突出。进行地下水污染预警是保护地下水资源的一个有效措施,当前国内外相关研究刚刚起步,有关预警理论、方法和技术框架仍未形成一套完善的体系。本文简述了地下水污染预警的研究现状及存在的不足,并以中国北方某铬渣场地为例,根据当地的水文地质条件,利用数学模型建立了地下水污染预警模型,给出了不同等级的地下水污染预警分区,研究结果可为当地地下水污染防治和地下水污染控制规划提供科学依据。     

北京市建设地下水库的思考

为满足城市用水需求,北京市持续超采地下水,使地下水位不断下降,地质环境问题日益突出。地下水库作为一种高效的水资源调控工程措施,对于缓解供水紧张局面具有重要意义。文章分析了在水资源短缺以及南水北调工程即将通水形势下,北京建设地下水库的必要性,阐述了北京市地下水库的研究基础,讨论了地下水库的建设条件和工作方法,并对地下水库运行管理提出需要关注的问题,为北京市研究建设地下水库提供参考。     

Impact of intense exploitation on the groundwater balance and flow within Mullusi aquifer (arid zone, west Iraq)

The main results that derived from this study is the quantitative determination of subsurface water balance and the water loses along flow line during drought decade (before 2000–2009), with intense exploitation of groundwater from water wells. The hydrogeological data are presented as spatial distribution maps and three dimensional models. The results are correlated with the main hydrogeologic control points including (storage and transmissivity coefficients, groundwater depths, aquifers thickness, lateral extensions, well productivity) to determine the preferable hydrogeologic districts for development and exploitations, avoiding groundwater depletion as captured zone flow. Based on the isotope analysis of deuterium, oxygen-18, tritium, carbon-13, and carbon-14, the recharge of the aquifer is originated to direct infiltration of atmospheric water through exposure outcrops within Hauran catchments area. The isotope compositions also show that the groundwater is a mixture of an old groundwater with modern recharge in the areas adjacent to Rutba. The fact that the Mullusi aquifer is of major importance as the water supply of people in Rutba region, particularly, for increasing demand of water resources and sustainability assessment in the future, this study developed a reliable strategic suggested plan in groundwater supply, based on groundwater exploitation and amount of safe yield within Dhabaa basin.     

GIS based groundwater modeling study to assess the effect of artificial recharge: A case study from Kodaganar river basin,Dindigul district,Tamil Nadu

Groundwater is a dynamic and replenishable natural resource. The numerical modeling techniques serve as a tool to assess the effect of artificial recharge from the water conservation structures and its response with the aquifers under different recharge conditions. The objective of the present study is to identify the suitable sites for artificial recharge structures to augment groundwater resources and assess its performance through the integrated approach of Geographic Information System (GIS) and numerical groundwater modeling techniques using MODFLOW software for the watershed located in the Kodaganar river basin, Dindigul district, Tamil Nadu. Thematic layers such as geology, geomorphology, soil, runoff, land use and slope were integrated to prepare the groundwater prospect and recharge site map. These potential zones were categorized as good (23%), moderate (54%), and poor (23%) zones with respect to the assigned weightage of different thematic layers. The major artificial recharge structures like percolation ponds and check dams were recommended based on the drainage morphology in the watershed. Finally, a threelayer groundwater flow model was developed. The model was calibrated in two stages, which involved steady and transient state condition. The transient calibration was carried out for the time period from January 1989 to December 2008. The groundwater model was validated after model calibration. The prediction scenario was carried out after the transient calibration for the time period of year up to 2013. The results show that there is 15 to 38% increase in groundwater quantity due to artificial recharge. The present study is useful to assess the effect of artificial recharge from the proposed artificial structures by integrating GIS and groundwater model together to arrive at reasonable results.     

Managed aquifer recharge (MAR) by the construction of subsurface dams in the semi-arid regions: A case study of the Kalangi river basin, Andhra Pradesh

Overuse of groundwater in coastal areas, due to high population and agricultural activity results in seawater intrusion into the coastal aquifer. This paper presents the control measures taken to manage aquifer recharge (MAR) and also to overcome the problem of seawater intrusion into the coastal aquifer along the Kalangi river, Nellore district of Andhra Pradesh, India having connectivity with Pulicat (saltwater) lake estuary. Due to overexploitation of groundwater and less rainfall in past years, adjacent seawater has started intruding in the Kalangi river sub-surface and deteriorating groundwater quality up to 11.6 km from the confluence of the river with Pulicat lake. To prevent this situtation, subsurface dams were constructed in traditional manner using local earth material in three different places across the Kalangi river near Sullurpet town. The water storage capacities calculated after the sub-surface dams’ construction are 1.28 mcft at GK Engineering College, 6.23 mcft at Challamagudi and 3.143 mcft at Holy Cross School sites. The Holy Cross School sub-surface dam is the first full scale dam-cum-check dam constructed to prevent salt water intrusion in the Kalangi river at Sullurpet, Nellore district, Andhra Pradesh. At the Kalangi river estuary portion (at the mouth of sea) a groyne was reconstructed over old groyne site with the introduction of clay bed and wooden sheet piles at down stream. Apart from prevention of sea water entry into Kalangi river sub-surface (during seasons) the groyne top level was raised to prevent mixing of high sea water tides with fresh water and ensuring additional storage of fresh water at upstream side. The reconstructed groyne was serving the purpose of obstructing the surface seawater entry in the Kalangi river and water quality has improved in the river as well as in the wells. After construction of sub-surface dam, as per the Simpson ratio classification, there is substantial improvement of water quality in the SHAR infiltration well situated near the Holy Cross School sub-surface dam.     

Induced recharge at new dam sites—Sana’a Basin, Yemen

In approaching the task of developing recharge estimates for dam sites, several constraints are apparent, including the scarcity of site-specific data for the selected new sites and the availability of simple yet robust analysis techniques. Combined, these constraints require an approach which involves best use of available data, adoption of relatively simple analytical approximations of reality, and the adoption of several key assumptions. In arid country with limited resources, two simple techniques have been used for recharge estimation: (1) a simple water balance model in spreadsheet and (2) a more refined Darcian approach involving an analytical approximation of a flow-net solution. By applying the two models at three new dam sites, the amount of recharge rates calculated over the period 2007–2026 was close. This is because, despite Darcian approach that should have affected the recharge rate as other parameters were introduced in the calculation of q _t , e.g., groundwater table mound, reservoir water height, etc., the results show general agreement between the two methods which seem to validate the assumptions made in both methods. A general conclusion of this comparison is that the hydraulic conductivity (K) is the main determining factor in recharge calculations in these situations. The water balance model was used to estimate recharge at Wadi Bahaman, under gravity and cascade dams’ scenarios. Using gravity dam at Wadi Bahaman for groundwater recharge proved not suitable based on the relatively small predicted runoff from a small catchment area and geological concerns in the abutment areas. Instead, a series of three low check dams (2 to 4 m high) was proposed. These check dams will slow down the runoff flow, form small reservoirs, and enhance recharge along the valley, without requiring expensive foundations. Estimated groundwater recharge under cascade dams (141,407 m³/year) is greater than recharge estimated for gravity dam (103,853 m³/year) by at least 36%.     

Stratigraphic architecture and anthropic impacts on subsoil to assess the intrinsic potential vulnerability of groundwater: the northeastern Campania Plain case study, southern Italy

This study attempts to assess the aquifer vulnerability in the northeastern sector of the Campania Plain (southern Italy). The area is a highly populated region with anthropic impacts caused by rapid urban growth, quarrying, agricultural and industrial activities and uncontrolled waste storage. The main geologic feature of this plain is the alternation of alluvial/transitional and volcaniclastic deposits of Late Pleistocene–Holocene age. The study was performed integrating different sets of geologic and environmental data to restore the stratigraphic architecture and to assess anthropic impacts on subsoil. The reconstruction of stratigraphic subsurface architecture was based on remarkable geodatabase, concerning well log stratigraphies. Specific insights have been delineated on the volcaniclastic lithofacies heteropies across the entire area of study to highlight the differences in lithification degree and permeability. The contribution of pedogenesis on the reconstruction of the stratigraphic setting was also considered for the relative implications on groundwater quality concerns, as paleosols are usually regarded as aquitards. All of this information has been managed into a GIS project to produce a detailed 3D geological reconstruction, integrated with hydrogeological information to provide a model of the aquifer under study, highlighting sites of greater vulnerability to pollution. The anthropic impacts on subsoil were assessed by evaluating land-uses and overlaying the ANHI (Agricultural Nitrate Hazard Index) Map. The integration of the above datasets has allowed to check the reliability of the previsional empirical model with respect to the hydrostratigraphic model based on a thorough stratigraphic model and to verify the real potential of contamination.     

华北平原地下水演化及预测

华北平原近４０年来大规模地下水开采已导致一系列严重的环境问题,不利于当地经济可持续发展。本文根据地下水演化主要取决于自然因素和人类活动本着抓主要矛盾且易于操作的原理,主要研究降雨及开采地下水这一对主要供需预矛盾,利用水均衡方法并结合数理统计方法,建立地下水演化模型并预测该区主要地区和城市的水资源盈亏情况,为该区地下水合理开发利用及环境保护提供科学依据。     

西辽河(内蒙古)严重缺水区地下水资源及开发利用对策

西辽河(内蒙古境内)严重缺水区位于内蒙古自治区翁牛特旗—库伦旗一带。在地表水严重匮乏的干旱、半干旱地区,地下水一直是该区工业生产、城镇居民生活及农村人畜用水的主要水源,合理开发利用十分重要。通过研究地下水资源的分布特点及开发利用条件,分析地下水资源供需平衡及用水现状,提出合理开发利用地下水资源存在的主要问题及相应的对策与建议。研究表明,只有查明地下水储量,对地下水实行统一规划,统一管理,防止水污染,提倡节约用水,积极推行地表水和地下水联合调度,才能合理开发利用地下水资源。