Saltwater Intrusion In Aquifers Research Articles

The Effect of Saltwater Stress on the Performance of Cherry Tomatoes

Rising sea levels and saltwater intrusion in aquifers pose significant challenges for South Florida agriculture, leading to increased groundwater salinity and potential crop losses. Utilizing salttolerant crop species presents a potential solution for saline soils and regions with active saltwater intrusion. However, the effects of soil salinization through groundwater alone remains less studied. This research investigates the impact of short-term, below-ground saltwater stress on the growth, survival, and overall health of commonly grown cherry tomatoes (Solanum lycopersicum). The objectives of the study are to: 1) determine the impact of saline groundwater on tomato plant health and 2) compare the nutrient content of soil and tomato plant tissue exposed to varying concentrations of saline water. Established cherry tomato plants were exposed to varying concentrations of NaCl solution, simulating saltwater intrusion into groundwater. Over 28 days, plant height, leaf chlorophyll levels, and disease occurrences were monitored. It was found that the NaCl treatments did not significantly affect cherry tomato performance under the parameters of height, chlorophyll levels, or leaf nutrition when compared to the control group. This study suggests that cherry tomatoes can tolerate short-term exposure to NaCl in groundwater. Further exploration of more intense salt stress conditions from groundwater could be beneficial for utilizing this crop in areas with saline soils or polluted groundwater. Identification of salt-tolerant cherry tomato varieties can provide alternative crop options for non-arable land affected by high soil salinity.

GLOBAL WATER SCARCITY DUE TO CLIMATE CHANGE AND ITS CONSERVATION STRATEGIES WITH SPECIAL REFERENCE TO INDIA : A REVIEW

The strategic importance of fresh water for global water and food security will probably intensify under climate change which worsen the situation as it leads to increased frequency and intensity of climatic extremes such as flood, drought, cyclone, heat/ cold waves, alteration in water cycle, water resources depletion, increased variability of precipitation, salt water intrusion in aquifers, increasing irrigation demand, decreasing soil moisture and rapid evaporation of surface water and many more. This review provides an insight about climate change and its impact on quantity and quality of water, water scarcity on a global scale with emphasis on Indian water resources, its availability and conservation strategies to mitigate water scarcity. Global warming resulting in climate change is expected to account for about 20% of the global increase in water scarcity. Global water consumption has increased six fold in last century and in coming decades is expected to grow rapidly. By 2025, 1.8 billion people will be living in countries or regions with absolute water scarcity, and two-thirds of the world's population could be living under water stressed conditions. African continent is the worst affected by the scarcity of water. The gross per capita water availability in India will decline from about 1820 m3 per year in 2001 to as low as about 1140 m3 per year in 2050. It is estimated that the country would need 1180 billion cubic meters (BCM) of water annually by 2050. So, there is an urgent need of sustainable utilization of water resources, formulation of climate adaption strategies, making the people and government aware about shrinking water resources as well as taking urgent action for conservation and harvesting of water at local, national and global scale.

Management of saltwater intrusion in coastal aquifers using different wells systems: a case study of the Nile Delta aquifer in Egypt

Saltwater intrusion (SWI) is a type of pollution that adversely affects the quality of groundwater in coastal aquifers. The Nile Delta aquifer (NDA) in Egypt contains a large amount of freshwater. Increasing abstraction from the aquifer and sea level rise have led to an increase in SWI, which has reached up to 100 km inland. Therefore, practical measures are required to prevent further SWI. This study aims to identify an optimal well system to manage the intrusion of saline water in NDA using a number of management systems, including pumping of brackish water, aquifer recharge, and abstraction of the freshwater. SEAWAT code is used to simulate SWI in the aquifer considering different scenarios of pumping and sea level rise. Four scenarios are used to control SWI, including: decreasing pumping from the aquifer, increasing recharge using treated waste water, increasing abstraction of brackish water for desalination, and a combination of these systems. The results showed that increasing recharge could lead to greater retardation of SWI (19.5%) than decreasing pumping (6.2%) and abstraction of brackish water (5.9%). However, a combined well system of pumping, recharge and abstraction is shown to be a more effective tool to control SWI in coastal aquifers, with retardation percentage of 21.3%.

Interface Flow With Vertically Varying Hydraulic Conductivity

AbstractWe present an approach for solving problems of saltwater intrusion in aquifers with an hydraulic conductivity that varies in the vertical direction. The approach is based on the concept of a comprehensive potential, whose gradient exactly represents the vertically integrated discharge, which is, by definition, a two‐dimensional vector. We apply the approach to an island in Sweden and use it to estimate maximum allowable pumping rates of wells that recover part of the infiltration on the island.

Hydrogeochemical characterization of the urban coastal aquifers of Napoli (southern Italy): an overview

The presence of phenomena of salt water intrusion in aquifers located in coastal urbanized areas, especially depended on the use of groundwater, is a widespread problem in the world. The study deals with the large coastal belt of the Municipality of Naples(southern Italy), located between the volcanic areas of the Somma-Vesuvius (East) and the Phlegrean Fields (West). Three different coastal sectors were analysed: the plain of Bagnoli-Fuorigrotta (BF), the area of Mount Echia (E) and the area of Eastern Naples (EN). Acquired chemical data allowed of the identification of three different groundwater chemical features and the prevalent absence of sea water contamination, mainly due to the low use of these waters. The study highlighted the chief role of the presence of faults in this volcanic area, favouring the upwelling of gases (prevalently CO2). These gases increase the groundwater reactivity causing, in the Mount Echia sector, the presence of sulphurous mineral waters and, in the Bagnoli-Fuorigrotta sector, determining the alteration of the natural relationship between freshwater and saltwater. Moreover, in the Eastern Naples sector, the occurrence of lenses of peat, which play an important hydrogeologic role as aquiclude, can determine reducing condition in the aquifers, with high concentrations in Fe and Mn.

Can beaches survive climate change?

AbstractAnthropogenic climate change is driving sea level rise, leading to numerous impacts on the coastal zone, such as increased coastal flooding, beach erosion, cliff failure, saltwater intrusion in aquifers, and groundwater inundation. Many beaches around the world are currently experiencing chronic erosion as a result of gradual, present‐day rates of sea level rise (about 3 mm/year) and human‐driven restrictions in sand supply (e.g., harbor dredging and river damming). Accelerated sea level rise threatens to worsen coastal erosion and challenge the very existence of natural beaches throughout the world. Understanding and predicting the rates of sea level rise and coastal erosion depends on integrating data on natural systems with computer simulations. Although many computer modeling approaches are available to simulate shoreline change, few are capable of making reliable long‐term predictions needed for full adaption or to enhance resilience. Recent advancements have allowed convincing decadal to centennial‐scale predictions of shoreline evolution. For example, along 500 km of the Southern California coast, a new model featuring data assimilation predicts that up to 67% of beaches may completely erode by 2100 without large‐scale human interventions. In spite of recent advancements, coastal evolution models must continue to improve in their theoretical framework, quantification of accuracy and uncertainty, computational efficiency, predictive capability, and integration with observed data, in order to meet the scientific and engineering challenges produced by a changing climate.

Integrating Decentralized Rainwater Management in Urban Planning and Design: Flood Resilient and Sustainable Water Management Using the Example of Coastal Cities in The Netherlands and Taiwan

Urbanized delta areas worldwide share a growing tendency of exposure to water stress induced by the effects of climate change and anthropogenic factors, threatening the operation of infrastructure systems and future urban development. The important synergistic impacts coexisting with freshwater scarcity are increasing urbanization rates, subsiding soils, saltwater intrusion in aquifers and rivers, coastal erosion, and increased flooding. Innovative design strategies and concepts for the integration of decentralized rainwater management measures can contribute to the integrated and climate resilient planning of urban spaces that are threatened by climate change scenarios that worsen the security of urban infrastructures and the future availability of fresh water. Decentralized rainwater management, including retention, storage, and reuse strategies that are integrated into spatial planning and urban design, can reduce flood risks while simultaneously enhancing freshwater availability. This paper discusses a paradigm shift in urban water management, from centralized to decentralized management (that is, from threats to opportunities), using the example of two case studies. Concepts and strategies for building climate resilient cities, which address flood control, the protection of freshwater resources, and the harmonization of a natural and more sustainable water balance, are presented for Almere (Rhine Schelde Delta, The Netherlands) and Hsingchu (Dotzpu Delta, Taiwan).

A method of lines approach for modelling saltwater intrusion in coastal aquifers

The equations governing saltwater intrusion in coastal aquifers are complex. Backward Euler time stepping approaches are often used to advance the solution to these equations in time, which typically requires that small time steps be taken in order to ensure that an accurate solution is obtained. We show that a method of lines approach incorporating variable order backward differentiation formulas can greatly improve the efficiency of the time stepping process. References K. Bajracharya, J. Arunakumaren, and W. J. Huxley. Numerical modelling of seawater intrusion in Gooburrum, Bundaberg, Queensland. In T. R. Weaver and C. R. Lawrence, editors, Proceedings, Groundwater: Sustainable Solutions, pages 613ñ--618. University of Melbourne, 1998. J. Bear. Hydraulics of groundwater. McGraw-Hill, New York, 1979. K. E. Brenan, S. L. Campbell, and L. R. Petzold. Numerical solution of initial-value problems in differential-algebraic equations. SIAM, Philadelphia, 1996. Jing-Ru Cheng, Robert O. Strobl, Gour-Tsyh Yeh, Hsin-Chi Lin, and Woo Hee Choi. Modeling of 2D density-dependent flow and transport in the subsurface. J. Hydrologic Eng., 3(4):248--257, 1998. doi:10.1061/(ASCE)1084-0699(1998)3:4(248) A. C. Hindmarsh, P. N. Brown, K. E. Grant, S. L. Lee, R. Serban, D. E. Shumaker, and C. S. Woodward. SUNDIALS: Suite of nonlinear and differential/algebraic equation solvers. ACM Transactions on Mathematical Software, 31(3):363--396, 2005. https://computation.llnl.gov/casc/nsde/pubs/toms_sundials.pdf P. S. Huyakorn, P. F. Andersen, J. W. Mercer, and Jr. H. O. White. Saltwater intrusion in aquifers: Development and testing of a three-dimensional, finite-element model. Water Resources Research, 23(2):293--312, 1987. F. Liu, V. V. Anh, I. Turner, K. Bajracharya, W. J. Huxley, and N. Su. A finite volume simulation model for saturated-unsaturated flow and application to Gooburrum, Bundaberg, Queensland, Australia. Applied Mathematical Modelling, 30(4):352--366, 2006. doi:10.1016/j.apm.2005.05.007 M. D. Tocci, C. T. Kelley, and C. T. Miller. Accurate and economical solution of the pressure-head form of richards' equation by the method of lines. Advances In Water Resources, 20(1):1--14, 1997. doi:10.1016/S0309-1708(96)00008-5 Q. Zhang, R. E. Volker, and D. A. Lockington. Numerical investigation of seawater intrusion at Gooburrum, Bundaberg, Queensland, Australia. Hydrogeology Journal, 12:674--687, 2004. doi:10.1007/s10040-004-0333-5

Improving fresh groundwater supply—problems and solutions

Many coastal regions in the world experience an intensive salt water intrusion in aquifers due to natural and anthropogenic causes. The salinisation of these groundwater systems can lead to a severe deterioration of the quality of existing fresh groundwater resources. In this paper, the characteristics of variable-density groundwater flow and the concept of an interface between fresh and saline groundwater are introduced. Problems associated with these groundwater resources are discussed, such as upconing of saline groundwater caused by excessive overpumping and salt water intrusion caused by global mean sea level rise. Possible human activities to compensate and control the salinisation of coastal aquifers are presented. Most countermeasures appear to be expensive, laborious and should be taken in time. Finally, the effect of lowering piezometric heads on the salinisation of the subsoil is illustrated in a Dutch aquifer system.

Picard and Newton linearization for the coupled model of saltwater intrusion in aquifers : M. Putti & C. Paniconi, Advances in Water Resources, 18(3), 1995, pp 159–170

Picard and Newton linearization for the coupled model of saltwater intrusion in aquifers : M. Putti & C. Paniconi, Advances in Water Resources, 18(3), 1995, pp 159–170

Picard and Newton linearization for the coupled model for saltwater intrusion in aquifers

Difficulties in the numerical solution of the partial differential equations governing seawater intrusion in aquifers arise from the coupling between the flow and transport equations and from the nonlinear aspects of this coupling. Several linearization approaches are discussed for the solution of the nonlinear system which results from a finite element discretization of the coupled equations. It is first shown that the most commonly used solution method can be viewed as a Picard linearization applied to the transport equation, with the coupling resolved by iteration over the two governing equations. The full Newton scheme for solving the coupled problem produces a Jacobian of size 2 N × 2 N, where N is the number of nodes in the discretization of both the flow and transport equations. To reduce the size and complexity of the full Newton scheme, a partial Newton method is proposed, which, like the Picard approach, produces matrix systems of size N × N. This scheme applies Newton linearization to the transport equation, and conventional iteration to resolve the coupling. Results from two- and three-dimensional test simulations show that the partial Newton scheme gives improved convergence and robustness compared to Picard linearization, especially for highly advective problems or large density ratios. Both approaches involve the solution of a symmetric (flow) and a nonsymmetric (transport) system of equations, and it is shown that the per iteration CPU cost for the partial Newton method is not significantly greater than that of the Picard scheme.

Saltwater intrusion in aquifers: Development and testing of a three‐dimensional finite element model

A three‐dimensional finite element model is developed for the simulation of saltwater intrusion in single and multiple coastal aquifer systems with either a confined or phreatic top aquifer. The model formulation is based on two governing equations, one for fluid flow and the other for salt transport. Density coupling of these equations is accounted for and handled using a Picard sequential solution algorithm with special provisions to enhance convergence of the iterative solution. Flexibility in the formulation allows for either three‐dimensional simulations or quasi three‐dimensional simulations, where flow and transport in aquitards are treated using one‐dimensional analytical and/or numerical approximations. Spatial discretization of three‐dimensional regions is performed using a vertical slicing approach designed to accommodate complex geometry with irregular boundaries, layering, and/or lateral discontinuity. This approach is effectively combined with the use of simple linear elements such as rectangular and triangular prisms, and composite hexahedra and pentahedra made up of tetrahedra. For these elements, computation of element matrices can be performed efficiently using influence coefficient formulas that avoid numerical integration. New transport influence coefficient formulas are presented for rectangular and triangular prism elements. Matrix assembly is performed slice by slice, and the matrix solution is achieved using a slice successive relaxation scheme. This permits a fairly large number of nodal unknowns (of the order of five to ten thousand) to be handled conveniently on small or medium‐size minicomputers. Flexibility of the formulation and matrix handling procedures also allows two‐dimensional and axisymmetric problems to be solved efficiently using single slice representations. Four examples are presented to demonstrate the model verification and utility. These problems represent a fair range of physical conditions. Where possible, simulation results are compared with previously published solutions.