Aquifer Sustainability Research Articles

Sustainable Development of Groundwater in East Owienat, Egypt

Groundwater is a vital water source in arid and semi-arid regions. In East Owienat area groundwater is an only available water source. This study assessed the characteristics of the hydrogeological system and the baseline condition of the aquifer using field data and numerical modeling. The main objective of this research is to study the impacts of groundwater development on groundwater aquifer sustainability and to select the optimum development scenario, which achieves sustainable development with a minimal effect on aquifer potentiality. Groundwater flow was simulated using the Visual MODFLOW package. The model was calibrated under steady state conditions in January 1985. The model was verified from January 1985 to January 2018 according to observation point's data. The calibrated model then was used for the prediction simulations. Different extraction scenarios were suggested and evaluated to predict the behavior of groundwater aquifer and select the most feasible scenario. The evaluated groundwater extraction scenarios included: current extraction, proposed extraction and seasonally pumping of groundwater scenario. The results indicated that the seasonal operational aquifer scenario is highly recommended for a long-term management plan to achieve groundwater sustainability. Keywords: Groundwater; Sustainable Development; Modflow; East Owienat. DOI: 10.7176/CER/12-7-06 Publication date: July 31 st 2020

Groundwater Level Mapping Tool: An open source web application for assessing groundwater sustainability

Decision makers need an accurate understanding of aquifer storage trends to effectively manage groundwater resources. Groundwater is difficult to monitor and quantify since the data collected from monitoring wells are often available only at irregular and infrequent intervals. We present an open-source web application (app) to visualize groundwater data over time and automatically calculate changes in aquifer storage volume to help managers assess aquifer sustainability. This app uses a novel multi-linear regression (MLR) algorithm to impute missing data for infrequently sampled wells, using correlated data from other wells in the same aquifer. The app uses this MLR-imputed data to spatially interpolate water levels throughout an aquifer at user-specified time steps using GSLIB Kriging code. Based on our tests of unconfined aquifer systems, the imputed data increased the accuracy of the spatial interpolation over standard methods and resulted in estimates of aquifer storage change comparable to those of detailed USGS studies.

Are Groundwater Level Data Collected by Citizen Scientists Trustworthy? A Cautionary Tale.

Public participation in groundwater projects is increasing, however, the efficacy of the data collected in such studies, is not well-documented in the literature. In this study, the authors describe a citizen science project focused on measuring and recording groundwater levels in an aquifer and evaluate whether the groundwater data collected by the participants are trustworthy. A total of 31 participants were initially recruited to measure and record groundwater levels from 29 monitoring wells on a barrier island. Following recruitment, the authors provided training to the citizen scientists by introducing groundwater concepts, and showing the participants how to measure, record and report groundwater level data (over an 81-day period) with an electronic water level meter. The water level data recorded by the citizen scientists (i.e., 35 time series datasets with over 450 unique measurements) were then compared to high frequency data recorded by automated water level loggers that were already deployed in the groundwater monitoring wells to assess the trustworthiness of the data. Trustworthiness was evaluated using measures of reliability (i.e., consistency in measuring the same thing), validity (i.e., degree to which results are truthful), and other standard graphical and statistical techniques. The results suggest that with proper training, guidance, and motivation, citizen scientists can collect trustworthy groundwater level data that could be useful for monitoring the sustainability of aquifers and managing of groundwater levels. It is noted however, that such positive outcomes require significant investments of time and effort on the part of the project managers.

Introduction

Introduction

Low-Cost, Open Source Wireless Sensor Network for Real-Time, Scalable Groundwater Monitoring

Population growth, climate uncertainties, and unsustainable groundwater pumping challenge aquifer sustainability worldwide. Efficient and data-driven groundwater supply management is a necessity to maintain essential water-dependent functions. Currently, managers lack the cost-effective, scalable, and reliable groundwater monitoring systems needed to collect vital groundwater data. Existing automated groundwater monitoring systems tend to be cost-prohibitive, and manual methods lack the spatial or temporal resolution to sufficiently meet critical water modeling, management, and policy objectives. In this study, we developed a fully automated, open source, low cost wireless sensor network (LCSN) for real-time groundwater data acquisition, processing, and visualization in the South American Subbasin Groundwater Observatory (GWO), located in California, USA. We demonstrate the steps taken to create the GWO, including field, hardware, software, and data pipeline components so that it may be easily reproduced in new areas. We find that the GWO is comparable in cost to manual measurements at a weekly measurement frequency, and costs between three and four times less than comparable commercially available telemetry and dashboard systems, largely due to the use of free open source software to acquire, clean, store, and visualize data. The open source-powered GWO thus lowers the financial and technical barrier of entry for real-time groundwater monitoring, creating the potential for more informed water management worldwide, particularly in regions whose managers are restricted by the high capital costs of commercial monitoring systems.

Urban growth and groundwater sustainability: Evaluating spatially distributed recharge alternatives in the Mexico City Metropolitan Area

Groundwater-dependent cities face increasing population and changes in urban land use, threatening long-term aquifer sustainability by simultaneously increasing pumping demand while modifying recharge rates. Aquifer management involves a portfolio of alternatives to balance the sustainability of multiple water supply sources, including novel recharge alternatives to supplement traditional groundwater and surface water sources. However, potential managed aquifer recharge solutions can lead to unintended consequences as modern infrastructure and management alter natural hydrology, changing the underlying groundwater paradigm. This study uses a multiobjective analysis approach to evaluate the performance of spatially distributed aquifer management alternatives for the Mexico City Metropolitan Area (MCMA), a region where the population has increased by 48% and urban land use by 35% in the last 30 years. Recharge alternatives are evaluated using a physically based groundwater model that incorporates land and water use trends, and include: repairs to the water supply distribution network, increased wastewater treatment and infiltration, and increased infiltration of imported water supplies. These alternatives are compared according to planning objectives aggregated over three overlapping subregions within the model to minimize energy use for pumping, minimize water quality risks in subsidence-prone areas, and minimize groundwater flooding in urban areas. Results indicate that management alternatives resulting in equivalent changes in storage can exhibit spatially distinct reductions in drawdown over the historical period. Additionally, combining multiple alternatives results in a more than an additive risk of groundwater flooding, demonstrating the need for mitigation of rising water tables. This model will serve as the basis for future spatial optimization studies under future climate and land use scenarios. These approaches have broad applicability in other rapidly urbanizing regions dependent on groundwater supplies.

Potential infiltration and morphometry in the Arroyo Grande basin, Sucre Colombia

For areas that supply underground water sources, it is important to identify the conditions of circulation and infiltration of surface water as a fundamental contribution to the recharge, sustainability and protection of aquifers. A study of the potential infiltration capacity considering the geomorphological aspects in the Arroyo Grande basin, Sucre, Colombia is presented. The aquifers of the study area are at risk of water supply due to the intense extraction and contamination by urban discharges in the surface currents of the basin. Morphometric indicators were applied to study the forms and dynamics of currents; For the estimation of the potential infiltration, the curve number method (CN-SCS) was used; all analyzes were performed with GIS tools. The results described the drainage conditions of the surface, identified the areas with the highest Infiltration potential over the Morroa aquifer, and the factors that directly influence the water regulation process.

Long-term (1970s–2016) changes in groundwater geochemistry in the High Plains aquifer in south-central Kansas, USA

Changes in groundwater chemistry in the Great Bend Prairie aquifer, a portion of the High Plains aquifer in south-central Kansas (USA), were studied in order to better understand factors influencing groundwater quality and aquifer sustainability. To assess changes, groundwater samples from 22 monitoring wells were analyzed during 2016. Results were then compared to data obtained previously from the same wells in the 1970s and 1980s. Of the wells sampled, 13 wells were screened near the water table (average depth 22 m) and 9 wells were screened near the aquifer base (average depth 41 m). Nitrate levels in 2016 were higher for 20 of 21 wells with data available for comparison. The average increase for shallow-aquifer and aquifer-base samples was 9.5 (standard deviation, SD, 12.9) and 3.4 (SD 3.1) mg/L as N, respectively. Nitrate isotope ratios (δ15N-NO3 and δ18O-NO3) of the 2016 samples are consistent with nitrification of ammonium-based fertilizers as the nitrate source with potential contributions from animal waste. Total dissolved solute levels were also higher in samples from nine of 12 shallow-aquifer wells and four of eight aquifer-base wells, with average increases of 191 (SD 238) and 194 (SD 133) mg/L, respectively. Taken together, the results demonstrate that water quality has decreased considerably over the past 40 years primarily because of fertilizer use, but that groundwater mixing, evapotranspiration, and potentially animal waste inputs also affected groundwater chemistry. These findings help identify the scale of water-quality degradation in the High Plains aquifer.

As características mutáveis da sustentabilidade das águas subterrâneas no Paquistão de 2002 a 2016

Groundwater is regarded as one of the most reliable and vulnerable sources of drinking water in many countries. Declining groundwater levels, due to over-exploitation and climate-change impacts, emphasize the need for sustainable management of this valuable resource. The concept of reliability-resiliency-vulnerability (RRV) has been adopted in this study to assess the spatial changes in the sustainability of aquifers for different periods to identify the main factors affecting groundwater sustainability in Pakistan. This is important for the country, as the substantial decline of groundwater levels in recent years has affected the water security of the growing economy. The satellite-based gridded Gravity Recovery and Climate Experiment (GRACE) groundwater anomaly data for the period 2002–2016 were used for this spatial assessment. The results revealed precipitation as the dominant factor associated with changing groundwater storage in Pakistan. A large decrease in aquifer storage was found over the study period. The groundwater-level decline was found to be greater in the region where agriculture is more intense, resulting in over-exploitation of groundwater for irrigation. The reduction of groundwater storage has led to a decrease in sustainability, especially in recent years (2008–2016) compared with previous periods (2002–2010 and 2005–2013). This study emphasized the need for groundwater resource management strategies such as reduction of groundwater abstraction in drought years, rescheduling the crop calendar to take advantage of rainfall, switching to less water-intensive crops, etc., particularly in groundwater depleting regions.

Groundwater Flow Model and Statistical Comparisons Used in Sustainability of Aquifers in Arid Regions

Groundwater provides the most important of the water resources used in the maintenance of communities in arid and semi-arid regions. In these areas, the usage of deep wells with motorized pumps in combination with the lack of effective regulatory policies and high human population growth (increase the water demand) impact the quality of the groundwater. This is especially the case for the San José del Cabo aquifer, in Baja California Sur. In the present study the groundwater flow system is analyzed in order to recognize the impact from variations in groundwater extraction and recharge on the phreatic levels and discharge values. In order to achieve this goal, a groundwater model was generated using the MODFLOW program. Different scenarios of extraction and recharge were calculated, based on different estimations of population growth. All the scenarios result in decreasing groundwater levels. As an important result, a relationship between the phreatic level and the extraction volume was found for the middle zone of the aquifer, where an average annual decrease of 0.5 m was observed from every 5 × 106 m3 additional extraction volume. This zone is up to three times more susceptible to changes in extraction values than the southern zone. As the results show, the San José del Cabo aquifer is in a fragile state where an increment in extraction is not an option without the use of remediation technics or new sources for water supply.

The economics of aquifer protection plans under climate water stress: New insights from hydroeconomic modeling

Where surface and groundwater are managed conjunctively, the stress on water supplies from climate change can significantly influence water use patterns as well as the economic value and sustainability of those uses. However, aquifer protection can be an expensive proposition because water uses that currently rely on aquifer pumping may produce considerable economic value that would be lost if protection measures are carried out. Evidence from climate-stressed regions has attracted research addressing the costs and benefits of aquifer protection plans. Despite these efforts, few peer-reviewed papers have examined water use patterns that minimize the economic costs of aquifer protection. This work presents an original approach to address that gap by developing and applying a basin scale hydroeconomic optimization model of North America’s Middle Rio Grande Basin to explore impacts of new policies not yet implemented supporting aquifer protection. It also gives model access to readers or stakeholders to experiment with their own scenarios to assess impacts of alternative aquifer protection plans. The model accounts for surface and groundwater storage, irrigation, urban, environmental, and recreational demands, surface water inflows under various climate scenarios, groundwater pumping and recharge, substitute water prices, crop water use, evaporation, as well as institutional constraints governing water use. The objective is implemented by finding the optimized discounted net present value of economic benefits summed over uses, sectors, and regions from use of surface water and connected aquifers. Results are shown for each of six water supply scenarios, two substitute water prices, and two system operation rules. To address impacts of aquifer protection targets, groundwater sustainability targets are specified and enforced as constraints for each of the region’s two major aquifers. We assess total and marginal cost of achieving two targeted aquifer protection levels by identifying optimized surface use and groundwater pumping for each of 24 scenarios. Results show that climate change, in the form of reduced and highly variable inflows, considerably drives up the cost of protecting aquifer sustainability, amplified by the conjunctive nature of the system. Future work points to a need to assess economic performance of various water conservation measures as well as reducing costs of substitute water through measures such as technical advance in desalination, recycling and reuse, substitution of other resources for water, better characterization of existing aquifers, and development of new groundwater supplies.

Effect of management strategies on reducing negative impacts of climate change on water resources of the Isfahan–Borkhar aquifer using MODFLOW

AbstractRecently, many studies have investigated the effect of climate change on groundwater resources in semiarid and arid areas and have shown adverse effects on groundwater recharge and water level. However, only a few studies have shown suitable strategies for reducing these adverse effects. In this study, climate conditions were predicted for the future period of 2020–2044, under the emission scenarios of RCP2.6, RCP4.5, and RCP8.5, for Isfahan–Borkhar aquifer, Isfahan, Iran, using MODFLOW‐2000 (MODFLOW is United States Geological Survey product). Results showed that the average groundwater level of the aquifer would decrease to 13, 15, and 16 m in 2012 to 2044 approximately under RCP2.6, RCP4.5, and RCP8.5 scenarios, respectively. Then, three groundwater sustainability management scenarios were defined that included 10%, 30%, and 50% reduction in groundwater extraction. These strategies simulated the reduced negative effects of climate change on the aquifer. The results showed that decreases in water withdrawal rates of 10%, 30%, and 50% under RCP8.5 scenario (critical scenario) could decrease the mean groundwater level by 14, 11, and 7 m, respectively. The main result of the study showed that 50% reduction in groundwater withdrawal may increase the groundwater levels significantly in order to restore the aquifer sustainability in the study area. In this study, with assuming that the current harvest of wells in the future period is constant, so the results of studies showed that for the aquifer's sustainability management, the water abstraction from the aquifer should reduce up to 50% of the existing wells. Changing the irrigation method from surface to subdroplet irrigation plays an important role in reducing the withdrawal from the aquifer. The results of a study in Iran have shown that the change in the irrigation method from surface to subdroplet irrigation causes a 40% reduction in water use for agriculture.

Assessment of age, origin, and sustainability of fossil aquifers: A geochemical and remote sensing-based approach

An integrated approach was developed to assess the sustainability, origin, age, evolution, and groundwater potential of large fossil aquifers using the Mega Aquifer System (MAS) (area: 2 × 106 km2) in the Arabian Peninsula as a test site. A two-step exercise was adopted, the sustainability of the MAS was first investigated through the analysis of GRACE data and land surface model (LSM) outputs. Then, integrated geochemical, remote sensing, and field studies were conducted to address the age, origin, hydrogeological setting, and evolution of the southern sections of the MAS (Rub Al Khali Aquifer System (RAKAS)), the area identified from the analysis of GRACE and LSMs as being the most suited for sustainable development. Analysis of GRACE and LSMs revealed: (1) the MAS central and northern sections are experiencing high groundwater extraction (6.6 km3/yr) and depletion rates (−2.8 ± 0.8 km3/yr) with minimum balancing potential through aquifer capture processes, yet sustainability could be achieved by reducing annual extraction by 2.8 km3, and (2) the MAS southern sections (Rub Al Khali Aquifer System (RAKAS)) are experiencing low groundwater depletion rates (eastern RAKAS: −1.8 ± 1.4 mm/yr) to steady-state conditions (western RAKAS: −0.73 ± 1.4 mm/yr). Geochemical, remote sensing, and field investigations over the RAKAS revealed: (1) the presence of west to east trending drainage networks and large-scale groundwater flow systems consistent with a meteoric source (precipitation over Red Sea Hills); (2) increasing 36Cl model ages along groundwater flow directions (up to 970,000 years), indicating aquifer recharge in wet Pleistocene periods; (3) progressive depletion in the O and H stable isotopic compositions of aquifers with increasing distance from the Red Sea Hills basement outcrops, indicating modest recharge during prevailing dry conditions; and (4) the presence of relatively fresh (TDS: 800–2800 mg/L) and non-radioactive (226Ra + 228Ra < 0.185 Bq/kg) water in western RAKAS. Findings suggest that sustainable agricultural development is achievable at current extraction rates in western RAKAS and provide a replicable and cost-effective model.

Sustainability and Conceptual Groundwater Hydraulic Models of Basement Aquifers

Abstract Groundwater flow of the basement terrains of the Ibarapa region was studied by carrying out pumping test and measurement of borehole inventory. The view was to identify the associated aquifer systems from the time-drawdown curves, quantify the estimable hydraulic properties and develop hypothetical models for the understanding of the groundwater flow in the area underlain by diverse crystalline bedrocks. Three aquifer types were identified namely, dual, leaky and regolith. The yield of groundwater in dual and leaky aquifers that dominated terrains underlain by amphibolite and gneisses was sustainable, but the discharge of regolith aquifers mainly associated with migmatite and granite terrains declined at late pumping stage. The transmissivities of the dual and leaky aquifers were between 2.02 and 11.65 m2/day, while those of regolith aquifers were mostly less than 1.00 m2/day. The average aquifer transmissivities in m2/day by bedrocks were: 6.85, 2.57, 0.76 and 1.72, correspondingly. The inter-relationships between transmissivities and groundwater discharge showed diverse aquifer representations, from sustainable high-yielding to unsustainable low-yielding types. Conscientious effort is, therefore, required for well construction in the area.

Aquifer Sustainability and the Use of Desalinated Seawater for Greenhouse Irrigation in the Campo de Níjar, Southeast Spain.

In the Campo de Níjar (southeast Spain), an intensive horticulture model under plastic has been developed based on the use of groundwater. For many years, aquifers have been overexploited, almost generating an environmental collapse. The construction of a desalination plant was planned to improve this situation and to achieve sustainable aquifer management. However, the aquifer is still being overexploited, since farmers scarcely use desalinated seawater for irrigation. In this paper, farmers irrigating with desalinated seawater are characterized, since they contribute to aquifer sustainability. The study aimed to identify the variables which condition the use of this water resource, as well as the kinds of incentives that encourage this option. For this purpose, a survey was undertaken within a sample of 110 farmers. A cluster analysis and a binary logistic regression were employed. The results from the cluster analysis allowed the characterization of farmers who use desalinated seawater for irrigation. Furthermore, the regression model showed the variables that determine a more intensive use of this irrigation source, such as crop diversification, availability of different water resources and the conductivity of aquifer water available for irrigation. The incentives promoting the use of desalinated seawater for irrigation that most encourage farmers are the implementation of tax relief, price reductions and the obligation to install rainwater collection systems.

Managing food and water security in Small Island States: New evidence from economic modelling of climate stressed groundwater resources

Climate-stressed groundwater resources present a growing challenge for protecting food security and economic sustainability, notably in Small Island Developing States (SIDS). These states are some of the most vulnerable to climate stress because of their large coastlines, vulnerability to rising sea levels, weak access to reliable surface water, and limited food production capacity for handling increased groundwater scarcity. Impacts of climate stressed groundwater resources brought on by irrigation and growing urban demand in SIDS continue to receive widespread attention by both scientists and policymakers. Policies that limit pumping to protect aquifer sustainability reduce short-term economic welfare by unknown amounts that would otherwise be secured by both urban and irrigation water users. Yet, little scholarly research has addressed economic impacts of climate-water stress for the special needs of SIDS for which urban and irrigation pumping compete hydrologically and economically over long time periods. The original contribution of this work is to address that gap by employing downscaled data on precipitation from Representative Concentration Pathways (RCP) climate scenarios. Its novel contribution is to conceptualize, develop, apply, and interpret an integrated hydro-economic framework to understand interconnected physical and economic linkages from managing an unconfined regional aquifer system under each of three climate and two policy scenarios. The application is to Barbados, a SIDS, for which current and future irrigation and urban demands compete for water. The framework integrates groundwater hydrology, climate scenarios, economics, land use, and groundwater management, with the intent to mitigate impacts of climate stress on current economic values of water as well as protecting future aquifer sustainability. Results provide a framework to guide water management for SIDS vulnerable to climate stress for which water of the right quantity, quality, timing, location, and price are essential elements of economic development.

Sustainability of aquifers supporting irrigated agriculture: a case study of the High Plains aquifer in Kansas

ABSTRACT The only means of moderating alarming depletion rates in many of the world’s major aquifers is to reduce pumping. We apply a new water-balance approach to assess the impact of pumping reductions in a portion of the High Plains aquifer in the United States. Although projected aquifer responses to pumping reductions vary, practically achievable reductions would have a large impact throughout the area. These findings demonstrate that modest pumping reductions could greatly enhance prospects for groundwater-supported irrigation in the High Plains aquifer and similar aquifers elsewhere.

Providing decision support system in groundwater resources management for the purpose of sustainable development

Decision support system (DSS) for sustainable development is an efficient tool in managing aquifers, since an aquifer as a complex system is not a structural issue due to varied components. In this article, software entitled DSS-SMGW-01 is developed based on the so-called DSS to realize sustainable management of groundwater. This system includes a database, a simulation model, and a decision-making model controlled through a graphical user interface. This software controls exploitation of groundwater in managing subunits and integrated management of water resources and consumptions. Furthermore, management options are evaluated by the software according to aquifer sustainability and socio-economic indicators. In this system, WEAP-MODFLOW linked model (Water Evaluation And Planning system dynamically linked to the United States Geological Survey modular finite-difference groundwater flow model), Analytic Hierarchy method, and Simple Additive Weighting method are utilized for simulation of groundwater resources system, weighting indicators and prioritizing options, respectively. In order to evaluate efficiency of the exerted system, Qazvin plain data was used and 68 experts from different parts of water industry in Iran were consulted to have the best analysis on weighting the indicators. Consequently, the prepared system was found to be successful in designing and prioritizing the seven managing indices.

An Assessment of Shallow Groundwater Wells In An Agricultural And Coastal Area In Göksu Delta, Turkey

The Göksu Delta of Turkey is an alluvial delta with intense agricultural activity and has great ecological and economic significance. Water samples were collected monthly from 24 wells in the study area, and 13 water quality parameters were examined. The objective of the study was also to determination the water quality in wells of the Göksu Delta and assess levels of salinisation in the region. Piper diagrams and the Geographic Information Systems (GIS) was used to generate ionic ratios to evaluate water quality in the study area in an efficient manner. Overall, the groundwater examined has medium levels of salinity and low sodium content. The ncrease in groundwater salinity and amounts of Na+ and Cl- are indicators of saltwater intrusion. Rock dissolution and ion exchange were also found to play an active role in the region. All of these factors affect the sustainability of the freshwater aquifers and lower their quality for wildlife species.

Assessment of village-wise groundwater draft for irrigation: a field-based study in hard-rock aquifers of central India

Extracted groundwater, 90% of which is used for irrigated agriculture, is central to the socio-economic development of India. A lack of regulation or implementation of regulations, alongside unrecorded extraction, often leads to over exploitation of large-scale common-pool resources like groundwater. Inevitably, management of groundwater extraction (draft) for irrigation is critical for sustainability of aquifers and the society at large. However, existing assessments of groundwater draft, which are mostly available at large spatial scales, are inadequate for managing groundwater resources that are primarily exploited by stakeholders at much finer scales. This study presents an estimate, projection and analysis of fine-scale groundwater draft in the Seonath-Kharun interfluve of central India. Using field surveys of instantaneous discharge from irrigation wells and boreholes, annual groundwater draft for irrigation in this area is estimated to be 212 × 106 m3, most of which (89%) is withdrawn during non-monsoon season. However, the density of wells/boreholes, and consequent extraction of groundwater, is controlled by the existing hydrogeological conditions. Based on trends in the number of abstraction structures (1982–2011), groundwater draft for the year 2020 is projected to be approximately 307 × 106 m3; hence, groundwater draft for irrigation in the study area is predicted to increase by ∼44% within a span of 8 years. Central to the work presented here is the approach for estimation and prediction of groundwater draft at finer scales, which can be extended to critical groundwater zones of the country.