scholarly journals Spatial and Temporal Changes of Groundwater Storage in the Quaternary Aquifer, UAE

Water ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 864
Author(s):  
Mohsen Sherif ◽  
Ahmed Sefelnasr ◽  
Abdel Azim Ebraheem ◽  
Mohamed Al Mulla ◽  
Mohamed Alzaabi ◽  
...  
Keyword(s):  
Water Resources ◽  
Brackish Water ◽  
Initial Conditions ◽  
Groundwater Resources ◽  
Effective Porosity ◽  
Groundwater Storage ◽  
Fresh Groundwater ◽  
Groundwater Exploitation ◽  
Quaternary Aquifer ◽  
Groundwater Levels

To study the temporal and spatial variations of the groundwater quantity and quality in response to intensive groundwater exploitation from the Quaternary aquifer in UAE, a water budget model with a cell size of one km2 was developed. The available historical records of groundwater levels and salinity have been used to develop the water table and salinity maps of UAE for the years 1969, 2005, 2010, and 2015. The available water resources and soil information system was used to facilitate validity, cogency, and consistency of the groundwater analysis. The spatial analysis module of GIS was used to define the aquifer setting, saturated thickness, aquifer base elevation, effective porosity, and groundwater salinity at each grid cell. The obtained results indicated that the volume of fresh groundwater resources in the Quaternary aquifer in UAE has decreased from 238 km3 in 1969 to around 10 km3 in 2015. A major part of these depleted fresh groundwater resources was replaced by brackish water, and, therefore, the total groundwater storage in this aquifer has only decreased from 977 in 1969 to 922 km3 in 2015, respectively. If the same groundwater exploitation continues, the freshwater storage in the surficial aquifer might be totally depleted in agricultural areas. Most probably, the brackish groundwater resources will be exploited. In such areas, more attention should be devoted to the management of brackish water resources to avoid the exacerbation of the saltwater intrusion problem. Despite the fact that the obtained results indicate the negative impacts of the improper water resources management in a small part of the arid area, the learned lessons are valid for other arid countries, in particular, using the proper steady state boundary conditions for the initial conditions in modeling the available future management alternatives.

Prediction and Optimization of Groundwater Development in Beijing Plain

2013 ◽  
Vol 477-478 ◽  
pp. 878-882
Author(s):  
Hai Peng Guo ◽  
Li Ya Wang ◽  
Shan Shan Fan
Keyword(s):  
Index System ◽  
Groundwater Resources ◽  
Groundwater Development ◽  
Evaluation Index System ◽  
Current Status ◽  
Groundwater Exploitation ◽  
Groundwater Levels ◽  
Beijing Plain ◽  
System A ◽  
Development And Utilization

Groundwater plays an important role and accounts for two-thirds of the total water supply in Beijing plain. Overexploitation of groundwater has caused continuous decline in groundwater levels, land subsidence and other environmental and ecological problems. To analyze current status and predict future trends in groundwater resources, a 3D transient groundwater flow model was established and used to simulate various groundwater resources development schemes. With considering some facters such as groundwater exploitation, river outflow, groundwater levels and so on, an evaluation index system was constructed. Based on this index system a multi-object decision model was established for estimation of groundwater development schemes and proven to be very useful for scientific analysis of reasonable development and utilization of groundwater resources.

Seasonal variation in water storage, vertical land motion and well levels: Implications for groundwater storage change in Central Valley

2020 ◽  
Author(s):  
Susanna Werth ◽  
Manoochehr Shirzaei
Keyword(s):  
Water Resources ◽  
Water Resources Management ◽  
Central Valley ◽  
Groundwater Storage ◽  
Resources Management ◽  
Groundwater Levels ◽  
Climate Research ◽  
Vertical Land Motion ◽  
Storage Change ◽  
Insight Into

<p>The establishment of the Inter-Commission Committee on "Geodesy for Climate Research" (ICCC) of the International Association of Geodesy (IAG) emphasizes on the usefulness of geodetic sensors for estimating high-resolution water mass variation, which is due to broad applications of geodetic tools ranging from water cycle studies to water resources management. As such, data from both GRACE missions continue to provide insight into the alarming rates of groundwater depletion in large aquifers worldwide. Observations of vertical land motion (VLM) from GPS and InSAR may reflect elastic responses of the Earth's crust to changes in mass load, including those in aquifers. However, above confined aquifers, VLM observations are dominated by poroelastic deformation processes. In previous works, Ojha et al. 2018 and 2019 show that GRACE-based estimates of groundwater storage change in the Central Valley, California, are consistent with those obtained by utilizing measurements of surface deformation. These studies also show that annual variations in VLM correlate well in time with groundwater levels.</p><p>Here, we investigate seasonal variations in groundwater storage by identifying how their effect is manifested in geodetic and hydrological datasets. Groundwater well observations in the Central Valley indicate maximum groundwater levels at the beginning of the year between February to April and lowest water levels in the middle of the year about July to October. Meanwhile, GRACE groundwater storage estimates peak about four months later. To get insight into the mechanisms leading to this discrepancy, we perform a Wavelet multi-resolution analysis of GRACE TWS variations and complementary groundwater, snowcap, soil moisture, and reservoir level variations. We show that the majority of the differences between wavelet spectrums at seasonal frequencies occur during drought periods when there is no supply of precipitation in the high elevations. We employ a 1D diffusion model to demonstrate that the variations in groundwater levels across the Central Valley are due to the propagation of the pressure front at recharge sites due to gradual snowmelt. Such a model could explain the different timing of peaks in groundwater time series based on satellite gravimetry compared to deformation and well observations. We also discuss that winter rains are not able to directly contribute to recharging deep aquifers in the Central Valley, whereas most of the recharge must source from lateral flow caused by differential pressure at the sites of snow-melt in the Sierra Nevada as well as from agricultural return flows.</p><p>This analysis addresses the question of how well the different geodetic signals that reflect groundwater discharge and recharge processes agree with one another and what are the possible causes of disagreements. We emphasize the need for interdisciplinary efforts for the successful integration of available geodetic and hydrological datasets to improve our ability to utilizing geodetic sensors for climate research and water resources management.</p><p>References:</p><p>Ojha, C., Werth, S., & Shirzaei, M. (2019). JGR, https://doi.org/10.1029/2018JB016083.</p><p>Ojha, C., M. Shirzaei, S. Werth, D. F. Argus, and T. G. Farr (2018), WRR, https://doi.org/10.1029/2017WR022250.</p>

scholarly journals Assessment of groundwater resources: Nauru project 2010 – 2019

2019 ◽  
Author(s):  
Luca Alberti ◽  
Ivana La Licata ◽  
Louis Bouchet
Keyword(s):  
Climate Changes ◽  
Numerical Models ◽  
Groundwater Resources ◽  
Small Islands ◽  
Groundwater Extraction ◽  
Fresh Groundwater ◽  
Groundwater Exploitation ◽  
The Pacific ◽  
Freshwater Resource

Nauru is a small limestone island in the Pacific region where, as in many small islands in the world, the population heavilyrely upon groundwater as primary freshwater resource, in conjunction with rainwater and desalinated water.The Nauru project started in 2010 and led by Politecnico di Milano (http://nauru.como.polimi.it/), consisted on the hydrogeological characterization of the northern part of the island and the implementation of 3 numerical models for: (1) understanding the mechanisms governing groundwater flow and accumulation, (2) assess the adequate sustainable fresh groundwater exploitation in order to prevent saltwater upconing occurrences in the area more suitable for groundwater extraction and (3) to simulate future scenarios based on climate changes and population growth.

scholarly journals Direct or indirect recharge on groundwater in the middle-latitude desert of Otindag, China?

2018 ◽  
Author(s):  
Bing-Qi Zhu ◽  
Xiao-Zong Ren ◽  
Patrick Rioual
Keyword(s):  
Asian Summer Monsoon ◽  
Groundwater Resources ◽  
Atmospheric Precipitation ◽  
Middle Latitude ◽  
Northern China ◽  
Suture Zone ◽  
Mountain Areas ◽  
Fresh Groundwater ◽  
Groundwater Exploitation ◽  
Desert Zone

Abstract. The Otindag Desert in the middle-latitude desert zone of northern Hemisphere (NH) is essential to livestock-economy and ecoenvironment of northern China. Many areas in this zone are unexpectedly rich with groundwater resources although they have been under arid or hyper-arid climate for a long time. Widespread fresh groundwater deep to 60 m was found at the eastern part of the Otindag Desert. The occurrence of this massive fresh groundwater raises doubts on the long-lasting hypothesis in academic circles that regional atmospheric precipitation or palaeowater, namely the direct recharge, is the source of water in the middle-latitude desert aquifers of northern China. Understanding of the recharge of this fresh groundwater is important in evaluating the feasibility of groundwater exploitation and utilization. In this study we conducted hydrogeochemical and isotopical analyses to assess possible origin and recharge of these groundwaters. The analytical results indicate that the fresh groundwater is neither originated from regional atmospheric precipitation derived from the Asian Summer Monsoon system, nor from palaeowater that formed during the last glacial period. These findings suggest that the groundwater in this desert is possible to originate from remote mountain areas via the faults of the Solonker Suture zone, including the Daxing’Anlin and Yinshan Mountains. In addition, it is concluded that the hygeodrological linkage between desert aquifers and mountain systems through the suture zone is crucial to the hydrological functioning of the Otindag aquifer. This suggests that the modern indirect recharge mechanism, instead of the direct recharge and the palaeo-water recharge, is the most significant for groundwaterrecharge in the Otindag Desert. This study provides a new perspective into the origin and evolution of groundwater resources in the middle-latitude desert zone of HA.

Groundwater and salinization risk: tapping works and management experience in the Mediterranean Area

2021 ◽  
Author(s):  
Giorgio De Giorgio ◽  
Livia Emanuela Zuffianò ◽  
Maurizio Polemio
Keyword(s):  
Seawater Intrusion ◽  
Coastal Aquifers ◽  
Groundwater Resources ◽  
Regional Scale ◽  
Mediterranean Area ◽  
Management Approach ◽  
Fresh Groundwater ◽  
Groundwater Exploitation ◽  
Saline Groundwater ◽  
The Mediterranean

<p>The progressive population growth in coastal areas constitutes a huge worldwide problem, particularly relevant for coastal aquifers of the Mediterranean basin.</p><p>The increasing use of groundwater and the effect of seawater intrusion makes the study of coastal aquifers extremely relevant.</p><p>There are various measures, practices, and actions throughout the world for managing groundwater when this natural resource is subject to salinization risk.</p><p>This research focused on the seawater intrusion, classifies the different practical solutions protecting the groundwater through salinization mitigation and/or groundwater salinity improvements along the Mediterranean Area.</p><p>The literature review was based on 300 papers, which are mainly international journal articles (76%). The rest includes conference papers (11.8%), reports and theses (7%), and books or chapters of a book (25%).</p><p>Three main schematic groundwater management approaches can be distinguished for the use of groundwater resources at risk of salinization.</p><p>The <strong>engineering approaches</strong> pursue locally the discharge increase avoiding or controlling the salinity increase.</p><p>The most recent experiences of tapping submarine springs were realized using underground concrete dams, tools shaped like a parachute or tulip, or a fiberglass telescopic tube-bell, especially in the case of karstic aquifers.</p><p>The current widespread form of the engineering approach is to address the issue of groundwater exploitation by wells.</p><p>More complex solutions use subhorizontal designs. Subhorizontal tapping schemes were realized using tunneling and/or boring in combination with wide-diameter wells or shafts.</p><p>These works include horizontal drains or radial tunnels bored inside the saturated aquifer, shafts excavated down to the sea level with radial galleries or drains realized together with weirs to improve the regulation of the discharge rate and of salinization. Application of these solutions in areas where a thin fresh groundwater lens floats on the saline groundwater, as in the case of narrow and highly permeable islands, can yield high discharges, thus causing a very low drawdown over very wide areas. These solutions were successfully applied in Malta Islands.</p><p>The <strong>discharge management approach</strong> encompasses at least an entire coastal aquifer and defines rules concerning groundwater utilization and well discharge.</p><p>A multi-methodological approach based on monitoring networks, spatiotemporal analysis of groundwater quality changes, and multiparameter well logging is described in Apulian karstic coastal aquifers (Italy). The core is the definition of the salinity threshold value between pure fresh groundwater and saline groundwater mixture. The basic tools were defined to be simple and cost-effective to be applicable to the widest range of situations.</p><p>The <strong>water and land management approach</strong> should be applied on a regional scale. The main choice for this approach is pursuing water-saving measures and water demand adaptation. A multiple-users and multiple-resources-water supply system model was implemented to evaluate the effectiveness of the increasing maximum capacity of the surface reservoir and managed aquifer recharge in Apulia, a semi-arid region of Southern Italy.</p>

Remote sensing for assessment of groundwater resources, A case study of Stampriet Transboundary Aquifer

2021 ◽  
Author(s):  
Irene Kinoti ◽  
Marc Leblanc ◽  
Albert Olioso ◽  
Maciek Lubczynski ◽  
Angelique Poulain
Keyword(s):  
Remote Sensing ◽  
Water Resources ◽  
Groundwater Recharge ◽  
Real Time ◽  
Unsaturated Zone ◽  
Driving Forces ◽  
Groundwater Resources ◽  
Time Step ◽  
Groundwater Storage ◽  
Spatio Temporal

<p>Distributed integrated hydrological models (IHMs) are the most effective tools for estimating groundwater recharge in arid and semi-arid areas characterized by thick unsaturated zone. It is also important to capture spatio-temporal aquifer dynamics by using real-time or near-real-time data, for sustainable water resources management. However, such data is often unavailable in developing countries where monitoring networks are scarce. In recent years, remote sensing has played an important role in providing spatio-temporal information for evaluation and management of water resources. Nevertheless, application of remote sensing in groundwater studies is still limited and has mainly focused on assessment of groundwater recharge and groundwater storage as well as to provide boundary conditions and driving forces for both standalone groundwater models and IHMs. This study entails application of remote sensing data in developing the distributed integrated hydrological model for Stampriet transboundary multi-layered aquifer system shared between Namibia, Botswana and South Africa. A numerical model has been set – up using MODFLOW 6 coupled with the Unsaturated Zone Flow (UZF) Package where Climate Hazards Infrared Precipitation with stations (CHIRPS) rainfall data and Global Land Evaporation Amsterdam Model (GLEAM) potential evapotranspiration data were implemented as the model driving forces. Other input data used include digital elevation model, and land-use/landcover and also soil datasets to define unsaturated zone parameters. The model has been calibrated with groundwater level measurements as the state variables in transient conditions at daily time step for a period of 16 years. The model-simulated unsaturated zone and groundwater storage was compared to GRACE-derived sub-surface storage anomaly, further also used to constrain the model. The calibrated model provides spatio-temporal water flux dynamics as well as water balances and hence an understanding of the groundwater-resource dynamics and replenishment. This information is shown useful for proper management of the transboundary water resource as well as for policy making.</p>

How geomorphology can shape policy - Advances in system understanding of the Mekong delta reveal large anthropogenic impacts and drive policy change 

2021 ◽  
Author(s):  
Philip S.J. Minderhoud ◽  
Sepehr Eslami ◽  
Gualbert Oude Essink
Keyword(s):  
Focal Point ◽  
Anthropogenic Impacts ◽  
Groundwater Resources ◽  
Mekong Delta ◽  
River Channels ◽  
Fresh Groundwater ◽  
Aquifer System ◽  
Groundwater Levels ◽  
Delta System ◽  
Geomorphological Changes

<p><strong>Deltas</strong> have been a focal point for geomorphologists for decades, as these geologically young and transient landforms are formed and influenced by the <strong>interplay</strong> of many Earth surface processes. Hence delta systems are highly dynamic with sophisticated couplings and feedbacks that often span across multiple <strong>scientific domains</strong>. <strong>Climate change </strong>(including sea-level rise) and upstream damming alter the boundary conditions that determine how deltas form, grow, or shrink, however, the <strong>impact of human pressures</strong> within the delta system is becoming increasingly dominant in <strong>driving environmental change</strong>. Rapid economic development and urbanization of the world deltas often lead to overexploitation and exhaustion of natural resources, such as fresh water and sand. The impacts of such <strong>human-induced overexploitations</strong> have recently been shown to be dominant in driving the current geomorphological changes witnessed in the Mekong delta. The overexploitation of fresh <strong>groundwater</strong> is caused wide-spread decrease in groundwater levels in the aquifer-system, which leads to <strong>accelerated rates of land subsidence and salinization of fresh groundwater resources</strong>. The extraction of <strong>riverbed sand</strong> and upstream impoundments deepen the river channels which changes the fluvial and tidal dynamics leading to <strong>increased riverbank erosion and surface water salinization.</strong></p><p>Recent <strong>advances in geomorphological system understanding</strong> of the Mekong delta have revealed its critical state and show its disastrous trajectory towards which it is going when current business-as-usual practices are continued in the next decades. The scientific findings from several research groups have been instrumental to the quick increase in awareness and sense of urgency within governmental bodies and has laid the foundation for the development of more <strong>system-inclusive delta policy</strong>. Although the road towards effective mitigation of the root causes is still long, multi-disciplinary geomorphological research was effective in quantifying gradual but crucial human-induced changes in the delta system. This talk highlights some of the <strong>key scientific findings</strong> in the Mekong delta and elaborates on how science was instrumental to make the issues visible to a larger community of stakeholders and policymakers.</p>

Estimating regional to global fresh-brackish-salt groundwater occurrence to support future projections

2020 ◽  
Author(s):  
Marc F.P. Bierkens ◽  
Jude A. King ◽  
Joeri van Engelen ◽  
Jarno Verkaik ◽  
Daniel Zamrsky ◽  
...  
Keyword(s):  
Sea Level ◽  
Nile Delta ◽  
Initial Conditions ◽  
Groundwater Resources ◽  
Variable Density ◽  
Coastal Areas ◽  
Estimation Methods ◽  
Fresh Groundwater ◽  
Surface Sealing ◽  
Groundwater Occurrence

<p>Coastal areas, including deltas, are hotspots for population growth and economic development. The rising demand for fresh water that results from these developments has resulted in increased rates of groundwater pumping and an associated enhanced risk of groundwater salinization. Future sea-level rise, climate change and surface sealing due to urbanisation are likely to further increase salinization risk in the near future. In order to correctly project the future fate of fresh groundwater resources in coastal areas under climate and socio-economic change, a correct estimate of the current fresh-brackish-salt groundwater occurrence is imperative. The reason for this is that future salinity projections are very sensitive to initial conditions, due to the large inertia of variable-density groundwater systems. Here, we make a case that estimating the current fresh-brackish-salt groundwater distribution by itself is a major challenge. The presence of conductivity contrasts in coastal areas, the past occurrence of sea-level transgressions and the aforementioned system inertia makes that traditional estimation methods such as interpolations between in-situ salinity observations or equilibrium (steady-state) modelling approaches are incapable of producing sufficiently realistic fresh-brackish-salt groundwater distributions. Using examples from the Rhine-Meuse delta, the Nile delta and the global coast, we show that advancements in airborne geophysics and high-resolution paleo-groundwater modelling may be key to providing distributions that are both realistic and accurate.</p>

scholarly journals Groundwater Governance in Pakistan: From Colossal Development to Neglected Management

Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3017 ◽  
Author(s):  
Asad Sarwar Qureshi
Keyword(s):  
Water Resource Management ◽  
Groundwater Resources ◽  
Soil Salinization ◽  
Irrigated Agriculture ◽  
Management Approach ◽  
Groundwater Abstraction ◽  
Local Conditions ◽  
Groundwater Exploitation ◽  
Groundwater Levels ◽  
The World

Groundwater is playing an essential role in expanding irrigated agriculture in many parts of the world. Pakistan is the third-largest user of groundwater for irrigation in the world. The surface water supplies are sufficient to irrigate 27% of the area, whereas the remaining 73% is directly or indirectly irrigated using groundwater. The Punjab province uses more than 90% of the total groundwater abstraction. Currently, 1.2 million private tubewells are working in the country, out of which 85% are in Punjab, 6.4% are in Sindh, 3.8% are in Khyber-Pakhtunkhwa, and 4.8% are in Baluchistan. The total groundwater extraction in Pakistan is about 60 billion m3. The access to groundwater has helped farmers in securing food for the increasing population. However, unchecked groundwater exploitation has created severe environmental problems. These include rapidly falling groundwater levels in the irrigated areas and increased soil salinization problems. The groundwater levels in more than 50% of the irrigated areas of Punjab have dropped below 6 m, resulting in increased pumping cost and degraded groundwater quality. Despite hectic efforts, about 21% of the irrigated area is affected by different levels of salinity. The country has introduced numerous laws and regulations for the sustainable use and management of groundwater resources, but the success has so far been limited. Besides less respect for the law, unavailability of needed data and information, lack of political will and institutional arrangements are the primary reasons for poor groundwater management. Pakistan needs to revisit its strategies to make them adaptable to local conditions. An integrated water resource management approach that brings together relevant government departments, political leadership, knowledge institutions, and other stakeholders could be an attractive option.

scholarly journals INFILTRATION, EFFECTIVE POROSITY, TRANSMISSIBILITY AND CRITICAL YIELD OF WATER WELLS IN THE CARBONATE FISSURED AQUIFERS OF ATTICA – A CONTRIBUTION TO THE REGIONAL AND MANAGERIAL HYDROGEOLOGY

2017 ◽  
Vol 43 (4) ◽  
pp. 1758
Author(s):  
G. D. Kounis ◽  
K. G. Kounis
Keyword(s):  
Groundwater Resources ◽  
Fracture Network ◽  
Effective Porosity ◽  
Groundwater Exploitation ◽  
Water Wells ◽  
Fundamental Value ◽  
Critical Yield ◽  
Range Of Values ◽  
Tectonic Extension ◽  
Of Greece

In the hydrogeological practice and the groundwater resources management the accurate knowledge on the infiltration, effective porosity, transmissibility, and on the sustainable yield of water wells is of fundamental value. It is so, because these parameters are the information primarily required in prediction and decisions relevant to the ground water abstractions and the hydrogeological evaluation of specific sites. In this paper, we present these quantities from the carbonate fissured formations of Attica, non metamorphic (limestones, dolomitic limestones, dolomites ) and metamorphic (marbles), which all are of great areal extent and thus of great interest for groundwater exploitation. In addition, they show good geomorphological, structural and lithologic resemblance with analogous formations elsewhere in this country, so that figures calculated can be reliably transferred for use. In our work we used methods of increased reliability, and having known precipitation (P) we estimated — The Infiltration Index (Ic) from the yield of springs of well defined hydrogeological catchments (natural lysimeters) and results found fall in the range of values 0.38P < Ic < 0.42P — The Effective Porosity (pe), obviously secondary because of the nature of the carbonate aquifers ( fissure flow aquifers ). We calculated it from groundwater level hydrograph and values found are in between 1.31%< pe < 6.91% with the most common in between 1.58%< pe < 4.8% — The Transmissibility (T), we calculated from pumping tests, with Jacob method, using semilogarithmic plots of drawdowns (s) versus time (t) from start of pumping. Values found are mostly (70%)in the range 10m3 /h.m < T < 75m3 /h.m — The Critical Yield (Qc) of water wells we calculated from the “characteristic well curve” Q vs. s (with Q and s standing for yield and drawdown respectively). Values are mostly in between 15m3 /h < Qc <75 m3 /h. Cretaceous limestones showed the best of the parameters, followed by the marbles free of schist in- Δελτίο της Ελληνικής Γεωλογικής Εταιρίας, 2010 Bulletin of the Geological Society of Greece, 2010 Πρακτικά 12ου Διεθνούς Συνεδρίου Proceedings of the 12th International Congress Πάτρα, Μάιος 2010 Patras, May, 2010 tercalations and distant from schist boundary . Karstic processes on the fracture network, structures vulnerable to tectonic extension, like anticlines and tension faulting zones are the underlying reasons for better hydrogeologic performance and thus for higher values of the parameters studied. Dolomites outside the previous zones show very low values .

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