Estimating Groundwater Withdrawal in Poorly Gauged Agricultural Basins

A method is presented for estimating the annual groundwater withdrawal based on water balance resulting from surface and groundwater hydrological considerations. The unknown groundwater losses of the aquifer are estimated from the groundwater level fluctuations, the specific yield and the groundwater withdrawal prior to the installation of the irrigation network. The meteorological and hydrometric data are used in the Sacramento hydrological conceptual model for the estimation of the stored groundwater volume, via minimization of the difference between the simulated and measured stream discharge. Following the installation of the network due to poorly kept field records, an initial estimation of the groundwater withdrawal is made based on the fluctuations of the groundwater level, the specific yield, and the annual precipitation. The monthly stored groundwater volume is verified against the volume obtained during the recharge of the basin (November–April). The difference between the groundwater volume and the measured discharge of the basin (May–October) is in agreement with the initial estimation of the groundwater withdrawal. This method is applied successfully in an agricultural basin on the island of Crete, Greece and its novelty lies in the fact that it can be used in basins where groundwater withdrawal is not known or data is incomplete.     

Development of a Rainfall-Recharge Relationship for a Fractured Basaltic Aquifer in Central India

Groundwater being an important component of the hydrological cycle, estimation of its annual replenishment is essential to evolve a plan for optimum utilization. Groundwater balance approach, which is used extensively for the quantification of recharge and discharge components has been adopted for the rainfall-recharge estimation. Various inflow and outflow components have been identified and estimated for Sagar block in Sagar district of Madhya Pradesh, which faces acute water scarcity and continuous decline in groundwater levels. The computed recharge from rainfall varies between 122.45 and 183.71 MCM. The computed rainfall-recharge is compared with the Chaturvedi (1973), Kumar and Seethapathi (2002), Krishna (1987), and U.P. Irrigation Research Institute models. Models have also been developed to estimate rainfall-recharge for varying ranges of the annual rainfall and have been compared with the existing models. The relative error in estimation of rainfall-recharge from proposed models varies between 0.03 and 9.24%. The overall scenario is net decline in groundwater storage to an extent of ?31.31 MCM over a period of 16 years from 1985–1986 to 2000–2001. The trend analysis by Kendall’s rank correlation test, regression test for linear trend and Mann–Kendall test also clearly suggests falling trends in groundwater storage at 5% significant level, thereby demonstrating over-exploitation of the groundwater aquifer. This has subsequently led to progressive decline in groundwater table in the study area. Efforts should be initiated to tap the surface water by creating storages at suitable sites and artificial recharge practices should be encouraged after identifying suitable recharge zones. Conjunctive use of the surface and groundwater along with water conservation practices and groundwater management measures should be taken up to arrest the progressive decline in groundwater levels and over-exploitation of groundwater aquifer.     

Groundwater Flow Modeling of the Arlington Basin to Evaluate Management Strategies for Expansion of the Arlington Desalter Water Production

Water supply reliability in Southern California is facing serious problems because of reduction in the availability of water from the State Water Project and Colorado River, drought, and growing concerns about environmental restoration. Groundwater sources supply more than fifty-five percent of domestic demands in the Western Riverside County. Western Municipal Water District is planning to increase water supply reliability by expanding the Arlington Desalter production which requires additional groundwater pumping from the Arlington Basin. Western was concerned that increasing groundwater pumping will cause excessive decline in groundwater levels, leading to decreased yields at existing Desalter wells. Three-dimensional groundwater flow model was developed for the Arlington Basin to investigate different water management strategies. Five groundwater management scenarios were run for a 30-year time period. The five model runs were used to determine the feasibility of the Arlington aquifer system to supply groundwater to the Arlington Desalter over the 30-year life of the facility. Model simulation results showed that long-term groundwater pumping from the existing Desalter wells is not sustainable without artificial recharge. However two of the modeling scenarios which incorporated a combination of artificial recharge and new production wells, were shown to meet the increased Desalter yield requirements as well as minimize adverse impacts.     

Assessment of Sustainable Yield of Karst Water in Huaibei,China

This paper presents the assessment of sustainable yield in the Huaibei karst water area of Anhui province, China. A review of sustainable yield definition is introduced first in this paper, and sustainable development in karst areas is more difficult due to the complicated hydrogeologic conditions. General hydrogeology of the study area is provided to characterize hydraulic connections between the karst aquifer and an overlying porous aquifer. Groundwater level declines continuously due to over-exploitation of the karst groundwater, and two layers of groundwater dropping funnel were formed in Huaibei. These problems not only threaten the eco-geo-environment, but also compromise the water utilization which depends on the shallow porous water. A “critical water level” is proposed in this study to assess the sustainable yield, and it is determined by the historical exploitation data which represent the relationship between the karst water and the shallow porous water uses. A three layer Artificial Neural Network (ANN) model is used to understand the complex relationship of the karst water level and its influencing factors. Precipitation, exploitation and water level of latest period are chosen as the input nodes, seasonal records of water level are simulated by the ANN model. The sustainable yield is calculated by the trail-and-error adjusting method, and is equal to the pumping rate when the “critical water level” is maintained. The rate of 30.05 MCM/a is the sustainable yield for the Huaibei karst area in 2008, and it is less than the real pumping rate of 35.92 MCM/a. This assessment is meaningful to the management for the Huaibei karst water.     

Groundwater Recharge Zone Mapping Using GIS-Based Multi-criteria Analysis: A Case Study in Central Tunisia (Maknassy Basin)

The groundwater recharge zone mapping often requires a large amount of spatial information and criteria. Geographic information systems are capable of managing large amount of spatially related information, providing the ability to integrate multiple layers of information for multi-criteria analysis. To show the capabilities of GIS techniques for mapping groundwater refill zone in arid area, a study was carried out in the Maknassy basin located in Central Tunisia. This evaluation incorporates historic rainfall data analysis, watershed drainage density, surficial geology and aquifer boundary conditions. The study basin is categorized according to the previous criteria. Multi-criteria analysis is performed to evaluate suitability to the groundwater recharge for each factor, according to its associated weight. The thematic layers were integrated with one another using the weighted aggregation method to derive the groundwater recharge map. The results demonstrated that the GIS methodology has good functionality for mapping groundwater recharge zone.     

不同回灌补源模式下石川河富平地下水库数值模拟

石川河富平地区地下水长期处于采补失衡状态,大范围含水层被疏干,形成区域性降落漏斗,针对拟建的石川河富平地下水库,设置5种开采回灌方案,建立地下水流数值模型模拟不同方案下地下水库水位和蓄水库容变化情况。结果表明：各回灌方案在消除降落漏斗的同时,均能较好地恢复地下水水位,且不超过地下水库的调蓄上限水位;回灌量相同、回灌方式不同时,逐日回灌方式的水位恢复效果优于灌期+非灌期回灌方式,较2018年地下水水位平均抬升13.55 m,蓄水库容增加2.99×10⁸ m³;回灌量不同时,较大回灌量对地下水水位的影响大于回灌方式,即泾惠渠水源回灌时,水位抬升程度最大,为19.77 m,蓄水库容相应增加4.36×10⁸ m³。模拟结果可为地下水库的调蓄与运行提供参考。     

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.     

Remote Sensing and GIS Based Approach for Identification of Artificial Recharge Sites

The main aim of this paper is to demonstrate the capabilities of Remote Sensing (RS) and Geographic Information System (GIS) techniques for the demarcation of suitable sites for artificial recharge of groundwater aquifers, in the Loni watershed, located in Unnao and Raebareli districts, Uttar Pradesh, India. In this study, the SCS-CN model, groundwater depth data and morphological parameters (bifurcation ratio, elongation ratio, drainage density, ruggedness number, relief ratio, and circulatory ratio) have been used to delineate the recharge sites for undertaking water conservation measures. Augmentation of water resource is proposed in the watershed by constructing runoff storage structures, like check dam, percolation tank and nala bund. The site suitability for these water harvesting structures is determined by considering spatially varying parameters, like runoff potential, slope, groundwater fluctuation data and morphometric information of the watershed. GIS has been used as an effective tool to store, analyse and integrate spatial and attribute information pertaining to runoff, slope, drainage, groundwater fluctuation and morphometric characteristics for such studies.     

Recharge Wells Site Selection for Artificial Groundwater Recharge in an Urban Area Using Fuzzy Logic Technique

In arid and semi-arid area, groundwater is the most important water resources. Surface runoff harvesting is the most important process in the artificial recharge of groundwater that should increase groundwater quality and quantity. Urban impervious area provides an appropriate surface to produce adequate amounts of runoff. Groundwater recharge via recharge wells is one of the successful direct sub-surface methods. As many cities around the world face issues of water scarcity due to a fast and unsustainable urbanization, identify the best locations of groundwater recharge wells is an interesting relevant topic, especially in the arid and semi-arid area. Selection of a suitable area for groundwater recharge could increase efficiency of the recharge wells. In this study, the best location of recharge wells was investigated in Urmia city located in the North-west of Iran using fuzzy logic technique. In this study, locations of the drainage channel junctions with adequate potential of surface runoff were determined using SWMM. Appropriate locations for recharge wells were determined based on different layers including distance to runoff harvesting points, distance to the production water wells and depth of groundwater table. Hydraulic condition (hydraulic conductivity and specific recharge) was also used separately. The input layers were prepared using geostatistical interpolation techniques in ArcGIS 9.3 software. Mamdani fuzzy inference system was applied to incorporate the fuzzified input layers. Finally, in each area, pixels with the highest value were proposed as suitable locations for recharge wells. Based on the results, the number of pixels with “High” priorities increased when the hydraulic conductivity was used to site selection. Comparing hydraulic conductivity layer and selected location of the recharge wells shows that the area with low hydraulic conductivity and the area closed to the production water wells has not suitable priority for recharge wells.     

基于GIS的山东省地下水回灌补源管理信息系统

山东省地下水回灌补源管理信息系统是在MapGIS平台基础上开发完成的,它以山东省地下水回灌补源现状和前景预测及评价为主要研究内容.软件包括系统介绍、专业计算、信息查询、专题地图制作及帮助等模块,由数据库、图形库、属性库及模型库组成.该系统将有关山东省地下水回灌补源的所有信息包括文字、图形、影像、数据、声音等按时间、空间进行分类并做成不同的工程项目,进行空间分析和属性的汇总、统计、计算和查询.应用表明,系统通用性好,实用性强.     

Post Audit Analysis of a Groundwater Level Prediction Model in Developed Semiconfined Aquifer System

This paper assesses groundwater recharge under conditions of long-term groundwater pumping at the Ravnik pumping site in Croatia and analyses the groundwater level prediction model used in prior aquifer modelling. The results of model calibration revealed a very low net infiltration rate at the start of the pumping site’s operation. As the operation continued, the net infiltration rate slowly increased, while the percentage of infiltrated rainfall scaled up with increasing pumping rates. The predicted recharge of the covering aquitard amounts approximately 14–15 % of the mean annual precipitation. The aquifer recharge takes place from aquitard by seepage. A subsequent simulation of the pumping site’s operation was performed for the 9 years period on the assumption that the pumping rates and the groundwater recharge would be the same as those recorded during the final calibration years. Results show that the post audit measured levels correspond relatively well to the predicted levels and that increasing of the pumping rate causes changes in the water budget in advantage of net groundwater recharge as a consequence of spreading recharge area outside of previous model boundaries.     

水库防洪与补源优化调度及其风险分析

本文从洪水资源化与水资源可持续开发利用的角度建立水库防洪与补源优化调度的数学模型。利用流域产汇流模型计算入库洪水，并考虑短期降雨预报信息，将交互式生成技术与动态规划模型相结合来优化水库的调度方案，给出考虑洪水预报和降雨预报误差的水库防洪与补源优化调度风险率的定义与计算方法。将此模型和风险分析方法应用于大连市碧流河水库的防洪与补源联合优化调度中，对其风险值和补源效益进行了分析与计算。结果表明与常规调度相比，引洪补源优化调度能提高洪水资源利用率，补源效益十分显著。     

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.     

Evaluating Particle Deposition in the Artificial Groundwater Recharge Process by Physical and CT Imaging Experiments

Particle clogging in the artificial groundwater recharge process is one of the main factors influencing the artificial groundwater recharge efficiency, and particle deposition is the microscopic mechanism of the occurrence and development of particle clogging. Particle deposition in porous media changes the pore structure. The computed tomography (CT) scanning technique is a nondestructive testing method and determines the spatial distribution of pores in porous media. This study combines physical and CT scanning experiments to identify the change process of the pore structure in the artificial groundwater recharge process and compares the pore changes during recharge experiments between two columns containing different media. Porous media changes are observed with the CT scanning technique. The fractal theory is applied in the analysis of CT scan images and physical experiment results. The results of this study indicate that particle deposition can be examined by using CT scan images to obtain pore-related parameters, the internal pore structure of porous media determined through CT scan images can be applied in numerical simulation, and a mathematical model for particle deposition calculation in porous media is established. Compared to the physical experiment measurements, the spatial particle deposition information acquired with the CT scanning technique exhibits a higher accuracy and contains much more relevant data. Not only does this research reveal more clearly the particle clogging mechanism which is based on particle deposition, but also characterize, simulate and predict more accurately the development tendency of particle clogging during artificial groundwater recharge.

     

Assessment of Groundwater Potential in a Semi-Arid Region of India Using Remote Sensing,GIS and MCDM Techniques

Remote sensing (RS) and geographic information system (GIS) are promising tools for efficient planning and management of vital groundwater resources, especially in data-scarce developing nations. In this study, a standard methodology is proposed to delineate groundwater potential zones using integrated RS, GIS and multi-criteria decision making (MCDM) techniques. The developed methodology is demonstrated by a case study in Udaipur district of Rajasthan, western India. Initially, ten thematic layers, viz., topographic elevation, land slope, geomorphology, geology, soil, pre- and post-monsoon groundwater depths, annual net recharge, annual rainfall, and proximity to surface water bodies were considered in this study. These thematic layers were scrutinized by principal component analysis technique to select influential layers for groundwater prospecting. Selected seven thematic layers and their features were assigned suitable weights on the Saaty’s scale according to their relative importance in groundwater occurrence. The assigned weights of the thematic layers and their features were then normalized by using AHP (analytic hierarchy process) MCDM technique and eigenvector method. Finally, the selected thematic maps were integrated by weighted linear combination method in a GIS environment to generate a groundwater potential map. Thus, four groundwater potential zones were identified and demarcated in the study area, viz., ‘good’, ‘moderate’, ‘poor’ and ‘very poor’ based on groundwater potential index values. The area falling in the ‘good’ zone is about 2,113 km² (17% of the total study area), which encompasses major portions of Sarada, Salumber, Girwa, Dhariawad, and Mavli blocks of the study area. The northeast and southwest portions along with some scattered patches fall in the ‘moderate’ zone, which encompasses an area of 3,710 km² (about 29%). The ‘poor’ zone is dominant in the study area which covers an area of 4,599 km² (36% of the total area). The western portion and parts of eastern and southeast portions of the study area are characterized as having ‘very poor’ groundwater potential, and this zone covers an area of 2,273 km² (18%). Moreover, in the ‘good’ zone, the mean annually exploitable groundwater reserve is estimated at 0.026 million cubic metres per km² (MCM/km²), whereas it is 0.024 MCM/km² in the ‘moderate’ zone, 0.018 MCM/km² in the ‘poor’ zone, and 0.013 MCM/km² in the ‘very poor’ zone. The groundwater potential map was finally verified using the well yield data of 39 pumping wells, and the result was found satisfactory.     

Exploring the Mechanism of Surface and Ground Water through Data-Driven Techniques with Sensitivity Analysis for Water Resources Management

The over extraction of groundwater in central-western and southwestern Taiwan has resulted in serious land subsidence for decades. For making countermeasures in response to land subsidence, this study collects long-term hydrological data to explore the relationships between surface water and groundwater in various monitoring stations, and then constructs one-month-ahead forecast models by using data-driven techniques for the water resources management of the Zhuoshui River basin in Taiwan. The results demonstrate that the constructed models can accurately forecast monthly groundwater levels. The sensitivity analysis is next conducted on the input variables of the constructed models by using the partial derivative method. The analysis results reveal that streamflow is a predominant factor for groundwater level variation, and therefore streamflow management made by the upstream weir of the river would influence groundwater level variations. This study further implements several scenario analyses based on the interactive mechanism between groundwater and surface water in response to future climatic conditions and weir discharge management, respectively. The results of scenario analyses indicate that the groundwater recharge zone spreads along the Zhuoshui River while lateral and vertical recharge sources would cause different quantities and distribution patterns of groundwater recharge. Besides, an increase in weir discharge would improve groundwater recharge quantities with groundwater level variations at 0.12 m and 0.06 m in wet and dry seasons, respectively. As a consequence, the operation of weir discharge would play an import role in sustainable development of water resources management in the study area.     

Statistical Approach for Comprehensive Planning of Watershed Development Through Artificial Recharge

The purpose of the study is to demonstrate that cross-correlation analyses can contribute to the artificial recharge study in regional level of shallow aquifer. Correlations between hydrologic time series data were analyzed to identify the hydrogeologic location for potential artificial recharge in district Surat, Gujrat, India. The natural groundwater-level fluctuations and rainfall data were used for the analyses. The effective development of groundwater resources is essential for a country like India. India receives a good amount of average annual rainfall (114?cm) but most of its part goes waste as runoff. Over exploitation of groundwater due to increasing population is an additional cause of water crisis that results in the reduction in per capita availability of water in the country. Artificial recharge is essential for effective development of groundwater resources. An effort has been made to evaluate the suitable recharge zone considering rainfall by arresting runoff to restore groundwater conditions using a statistical technique. Groundwater system in a basaltic terrain where the top weathered regolith forms shallow aquifer the water table variation is directly influenced with temporal rainfall variation. Understanding of this relation is of critical importance to management of groundwater resources. A diagnostic relationship between recharge time series and water level time series is used to serve the purpose to determine the best site for groundwater recharge.     

马海盆地鱼卡河下游流域地下水均衡估算

鱼卡河下游位于柴达木盆地北部边缘的马海盆地,地下水是当地重要水源之一。通过搜集气象、水文资料及查阅相关文献,结合野外实地考查与试验,在掌握其水文地质基本特征的基础上,计算了其地下水系统2000~2013年的地下水均衡量。结果表明:对于流域内的地下水系统而言,河流渗漏补给是其主要补给源,约占总补给量的77.8%,而潜水蒸发是其主要排泄方式,约占整个系统排泄量的85.6%。流域内地下水年均补给总量为10 260.5万m~3/a,年均排泄总量为108 96.6万m~3/a,地下水均衡差为636.1万m~3/a,地下水位呈59 mm/a的下降趋势。研究结果对流域地下水资源量计算、地下水环境以及生态环境保护等均具有一定的参考价值。     

王赫生，李燕，周锴锷，张庆

为系统了解沙颖河流域地下水含水系统的补给源以及水化特征,在取样测试、现场监测的基础上,分别采用同位素、水文地球化学等方法,深入分析了沙颍河流域地下水含水系统特征。研究发现：沙颖河流域浅层地下水水化学类型自流域上游到下游呈HCO3-Ca+Mg型向HCO3+Cl-Ca+Mg型变化的趋势,中深层水以HCO3-Na型为主,局部呈HCO3+Cl型可能是浅层水混入的结果。采用铀不平衡方法识别地下水补给源,结果表明：浅层地下水补给源除降水外,还包括深层地下水的贡献;深层水来源包括大气降水、潜水和深层地下水3个补给源。各方法所得结论互相验证,研究结果可为流域内水循环模式研究、水污染防治等提供科学依据。     

河南省主要城市地下水超采区评价

在分析近期地下水观测、调查资料成果的基础上,描述了城市区域水文地质特性,并对17座主要城市不同含水层的年均地下水补给量、可开采量和实际开采量进行了计算评价。按照地下水超采区评价方法,划分出26处地下水超采区;提出了超采区地下水开发利用和管理的建议。