Bromidetochloride ratios indicate that chloride concentrations greater than seawater likely result from seawater altered by evaporation. Saltwater intrusion occurs when saline salty water is drawn into a freshwater aquifer. The coastal parts of citrus and hernando counties, fla. Ground water flow patterns and the zone of dispersion in an idealized, homogeneous coastal aquifer. Lateral intrusion of sea water because of overpumpming from the wells deeper saline water movement due to to upconing near coastal wells. Dec 10, 2011 groundwater pumping from kalbha and fujairah coastal aquifer of the united arab emirates uae has increased significantly during the last two decades to meet the agriculture water demands. The oxnard plain subbasin is a complex, multiformation, aquifer that has undergone several decades of groundwater extraction, and, which is known to experience seawater intrusion in several of its coastal areas. Coastal aquifers are highly sensitive to disturbances. The potential for saltwater intrusion in the potomac aquifers. It is shown that the tidal activity forces the sea water to intrude further inland and it also creates a thicker interface than would occur without tidal effects. This study was carried out with the objective of assessing the zone of mixing between seawater and groundwater in the coastal aquifer in south of chennai, tamil nadu, india using high.
Water can be contaminated by chemical spills which can get into surface waters or seep into the ground contaminating the aquifer. The floridan aquifer, a thick sequence of limestone and dolomite, is the principal source of water supply for the coastal parts of these two counties. Saltwater intrusion due to intensive ground water pumping is a. Simulation of seawater intrusion in ernakulam coast dipanjali d. Thus, sp monitoring can be used to facilitate more proactive management of abstraction and saline intrusion in coastal aquifers. Seawater intrusion is a major problem in urbanized coastal regions of india which is due to over exploitation of groundwater for various purposes. Monitoring of seawater intrusion in coastal aquifers86 melloul, a. Saltwater intrusion decreases freshwater storage in the aquifers, and, in extreme cases, can result in. This is an area with a strong manmade residential and tourist impact and, in the some cases, it is characterized by intensive agricultural practices. The induced gradients usually cause migration of salt.
Preliminary investigation of seawater intrusion into a. Saltwater intrusion in the floridan aquifer, coastal. Aug 08, 2016 identify saltwater intrusion in coastal aquifer 1. Pdf saline water intrusion into coastal aquifers dr. Saltwater intrusion is a welldocumented phenomenon that affects coastal aquifers worldwide barlow and wild, 2002. Essentially, saltwater intrusion is the effect caused by saltwater encroaching into a coastal aquifer, creating a saltwater wedge within the coastal aquifer. Seawater intrusion and how to prevent it the water. Monitoring networks ideally have wells located near the freshwatersaltwater interface that can be used to detect movement of this interface. Saltwater intrusion can naturally occur in coastal aquifers, owing to the hydraulic connection between groundwater and seawater. In many coastal aquifers, intrusion of seawater has become one of the major constraints imposed on groundwater utilization. Saltwater intrusion monitoring networks are designed to determine the inland extent of saltwater intruding from the ocean, and the distribution of saltwater that entered an aquifer by other means. Saltwater intrusion into the coastal aquifer has long been recognised as a major concern around the world. Flagler street, ec 3671, miami, fl 33174,usa email. Introduction almost all cases of seawater intrusion are recorded were caused by human activities because of intensive water pumping in coastal area.
Once an aquifer is intruded, it is difficult and extremely costly to restore the water quality of that aquifer. Tidal influence on seawater intrusion in unconfined coastal. Saltwater intrusion in a coastal aquifer environment barlow, 2003 in standard transport modeling using mt3dms, it is assumed that the solute is dilute and miscible soluble within groundwater, and that solute density does not affect the groundwater flow behaviour. Coastal aquifers are a nexus of the worlds oceanic and hydrologic ecosystems and provide a water source for the more than one billion people living. Published 9 january 20 20 iop publishing ltd environmental research letters, volume 8, number 1. A number of several methods have been used to control seawater intrusion to protect groundwater reserves in coastal aquifers. Seawater intrusion and how to prevent it the water network.
Water supply management modeling impact of saline intrusion on freshwater of a coastal aquifer yonas t. Societys college of engineering and technology, belgaum 590008 karnataka 2scientist e1, national institute of hydrology, roorkee 247667 uttaranchal abstract the development and management of fresh groundwater resources in. The potential for saltwater intrusion in the potomac. This idea led to the concept that perpetual circulation of sea water in coastal aquifers was a necessary. The installation of drainage canals, poorly cased wells, and water supply withdrawals have led to saltwater intrusion in the primary water use aquifers in southwest florida.
Of fresh water and salt water in a coastal aquifer by hilton h. Saltwater intrusion is the movement of saline water into freshwater aquifers, which can lead to groundwater quality degradation, including drinking water sources, and other consequences. In this study, a twodimensional seawat model is developed to simulate the seawater intrusion to coastal aquifers and brine water fresh water interaction in the south of laizhou bay. Remote detection of saline intrusion in a coastal aquifer. Pdf management of seawater intrusion in coastal aquifers. A variabledensity groundwater model is used to analyse the effects of tidal fluctuations on sea water intrusion in an unconfined aquifer. In the era of intense pressures on water resources, the loss of groundwater by increased seawater intrusion swi, driven by climate, sea level and landscape changes, may be critical for many people living in commonly populous coastal regions. Intrusion is a concern to those using groundwater for agricultural purposes since salty water is detrimental to most plants.
First, it should be able to solve the water table free surface problem. Saltwater intrusion occurs by many mechanisms, including lateral encroachment from coastal waters and vertical upconing near discharging wells figure 4 and figure 5. Gamma and electromagnetic induction em logs were obtained prior to the installation of the. The model was used to perform the parametric studies on the effect of location of the series of injection wells, spacing of well and fresh water injection rate on the sea water intrusion. Seawater intrusion extends 1 km inland in a coastal area in eastern greece and about 150 km 2 of the coastal aquifer has been intruded by saline water due to groundwater extraction through. Because saline water has a higher mineral content than. The goal of this research was to develop and test an approach for assessing the risk of swi in coastal aquifers. Saltwater intrusion and coastal aquifer sustainability. Smith abstract the most productive aquifers of the virginia coastal plain are in the potomac formation. Extensive research has been carried out to investigate saltwater intrusion in coastal aquifers. Em logs, in combination with the waterquality data, can be used to distinguish between highsalinity zones that are caused by seawater intrusion from those that are caused by freshening of a previouslysaline aquifer by recently recharged water. Preliminary study on seawater intrusion and aquifer freshening near reclaimed coastal area of shenzhen, china. Tidal influence on seawater intrusion in unconfined coastal aquifers woei keong kuan,1,2 guangqiu jin,3 pei xin,1 clare robinson,4 badin gibbes,5 and ling li1,3 received 16 march 2011. Monitoring of seawater intrusion in coastal aquifers.
Intrusion of saltwater is the most common contamination occurrence in coastal aquifers. Intruded ground water can also have detrimental effects on wetlands and estuaries of our coastal environments. Schematic of aquifer stratigraphy in the coastal zone of bangladesh ravenscroft and mcarthur, 2004 pliocene to holocene sediments are extensively tapped to supply drinking water and the majority of. Seawater intrusion and salinization processes assesment in a. Simulation of seawater intrusion in ernakulam coast. Delineating zones of seawater intrusion in a coastal. Parametric studies on saltwater intrusion into coastal. Modeling and analysis of seawater intrusion in the coastal aquifer.
Second, the numerical model should be able to simulate saltwater intrusion and therefore density. It is part of a series of reports describing the results of the u. Seawater intrusion is the first cause of contamination of. The oxnard plain subbasin features an important offshore hydrogeologic section that encompasses its boundary under seawater. Scale aquifer replenishment and seawater intrusion control using recycled water in southern california by r. Tidal effects on sea water intrusion in unconfined aquifers. Mapping the threat of seawater intrusion in a regional. Best practices for prevention of saltwater intrusion.
To prevent saltwater intrusion, some of the rules for well drilling should be followed. Saltwater intrusion is the induced flow of seawater into freshwater aquifers primarily caused by groundwater development near the coast. On the basis of a widely adopted sharp interface formulation, key. Seawater intrusion results in the contamination of coastal aquifers and, therefore a reduction in the available water for human consumption and agriculture. Changes of hydraulic gradient in groundwater aquifer are caused advance. Associated with this decline in water levels has been an increased potential for saltwater intrusion into the freshwater zones of the aquifer.
Optimal control of seawater intrusion in coastal aquifers. The relation between structure and saltwater intrusion in. Jul 31, 2007 seawater intrusion is often the consequence of freshwater aquifers overexploitation. A case study from bangladesh international organization of scientific research 9 p a g e figure. Inappropriate management of a coastal aquifer may lead to its destruction as a. Geological survey seawater intrusion in a coastal california aquifer u g s s this report is a summary of recent work on seawater intrusion in aquifers underlying the oxnard plain, ventura county, california. Seawater intrusion swi is one of the most challenging and widespread environmental problems that threaten the quality and sustainability of fresh groundwater resources in coastal aquifers. Saltwater intrusion solinst groundwater and surface water.
We examined the interplay between pumping regimes and recharge scenarios and its e ect on the saline water dis tribution. Saltwater intrusion and nitrate pollution in the coastal. Management of seawater intrusion in coastal aquifers. Many coastal areas are also heavily urbanized, a fact that makes the need for freshwater even more acute.
The development and management of fresh groundwater resources in coastal aquifers are seriously constrained by the presence of seawater intrusion. Salt water intrusion of coastal aquifers in the united states pdf. When groundwater is pumped from a coastal aquifer the fresh water level is lowered and the sea intrudes further into the aquifer. Assessment of seawater mixing in a coastal aquifer by high. A relation established between em logs, lithology, and water quality allowed for an estimate of the quality of water in intervals not sampled by wells. Seawater intrusion is often the consequence of freshwater aquifers overexploitation. Best practices for prevention of saltwater intrusion author. Tipping points for seawater intrusion in coastal aquifers. In aquifers adjacent to the coast and on islands like the. Fuentes florida international university, department of civil and environmental engineering,10555 w. When the extracted volumes are greater than the recharge, even on a local basis, a salinisation process begins in the aquifer as the.
It is a particularly important aquifer in coastal georgia and south carolina. In coastal regions, the quality of groundwater can be compromised due to saltwater intrusion swi caused by natural sea level rise slr and storm surge and anthropogenic pumping hazards. Seawater intrusion sgma usgs ca water science center. Katerina mazi 1,2,3, antonis d koussis 2,3 and georgia destouni 1,3. Saltwater intrusion occurs when saltwater moves into a freshwater aquifer. Saltwater incursion can occur in one of three ways, all as a result of overpumping. Pdf vulnerability of coastal aquifers to groundwater use. Dar es salaam quaternary coastal aquifer is a major source of water supply in dar es salaam city used for domestic, agricultural, and industrial uses. Tidal influence on seawater intrusion in unconfined. Pdf seawater intrusion and coastal aquifer management in. K august 2016 identify saltwater intrusion in coastal aquifer 2.
Preliminary investigation of seawater intrusion into a freshwater coastal aquifer lower south east foreword the department of environment, water and natural resources dewnr is responsible for the management of the states natural resources, ranging from policy leadership to onground delivery in. The rainy winter of 199192 and its influence on the groundwater quality in the coastal aquifer of israel, water and irrigation journal, 319. Modeling groundwater flow and seawater intrusion in the. Investigation of underground dam in coastal aquifers for. This is a very common and serious phenomenon all over the mediterranean basin, as well as in other areas with. Coastal aquifers serve as major sources for freshwater supply in many countries around the world, especially in arid and semiarid zones. The contours of specific conductivity, shown in fig. Lateral or horizontal intrusion occurs when excessive water withdrawals from an aquifer cause saline water from the coast to move inland. Modeling impact of saline intrusion on freshwater of a. Seawater intrusion associated with lowering of groundwater levels is an important issue in many of californias coastal groundwater basins. Kumar scientist e1 national institute of hydrology roorkee 247667 uttaranchal 1.
Geological survey usgs uses data collection, modeling tools, and scientific analysis to help water managers plan for, and assess, hydrologic issues that can cause undesirable results associated with groundwater use. Assessing the risk of saltwater intrusion in coastal aquifers. Tipping points for seawater intrusion in coastal aquifers under rising sea level. Seawater intrusion into coastal aquifers is a major problem in almost all parts of the world. Seawater intrusion can have major impacts on water quality in aquifers, rivers and estuaries, and can impact significantly on floodplain and wetland ecosystems. Seawater intrusion risks and controls for safe use of coastal. Saltwater intrusion can affect one well, or multiple wells in an aquifer, making the water unpotable unpleasant to drink. This study aims to define the principal hydrogeochemical processes controlling groundwater quality in the coastal strip of dar es salaam and to. However, groundwater overdraft and contamination are the major problems affecting the aquifer system. Well location at least 50 m from the coast well depth avoid deep. Gradual, but continual, increases in the chloride concentrations in water from the aquifer system have been observed in. The ufa beneath the southeastern us atlantic coastal plain and inner continental shelf is a major source of groundwater for four coastal states south carolina, georgia, florida, and alabama.
Management of groundwater in salt water ingress coastal. Seawater or saltwater intrusion swi is a major environmental threat and management challenge, particularly in areas where there is a history of overexploitation of coastal aquifers. Management of coastal aquifers involves decisions regarding the amount of water to be extracted andor injected into the aquifer 31, taking into account the interplay between the conditions of. Mapping saline water intrusion into the coastal aquifer with. Deterioration of this freshwater resource threatens the sustainability of the water supply of coastal communities and their economic development 1,2. As sea water intrusion progresses, existing pumping wells, especially those close to the coast, become saline and have to be abandoned. Groundwater pumping can reduce freshwater flow toward coastal discharge areas and cause saltwater to be drawn toward the freshwater zones of the aquifer. Risk of saltwater intrusion in coastal bedrock aquifers. In the context of coastal aquifers, technically this process is referred to as seawater intrusion, because saltwater can derive from different sources i. If the contaminant makes its way into coastal areas, then estuaries are also at risk. It was found that the reduction of seawater intrusion up to 60 90 % could be achieved through. Saltwater intrusion into coastal aquifers is a global issue, exacerbated by increasing demands for freshwater in coastal regions.
Water supplies in the potomac aquifers are impaired, however, by saltwater in some areas. A in coastal areas, fresh ground water discharges to. Causes global scale rising of sea water level caused by global warming, resulting in increase in the quantity of salt water putting pressure on fresh water aquifers change in precipitation slower recharge rate to replenish the amount of fresh water in the aquifer, making it more susceptible to the inland movement of salt. The increasing demand for fresh water in coastal regions is being met by the coastal aquifers. With excessive pumping the natural hydraulic gradient towards the sea may be reversed and the intrusion can then extend to the pumping borehole which becomes saline. Saltwater intrusion in the surficial aquifer system of the big cypress basin, southwest florida, and a proposed plan for improved salinity monitoring. The management of coastal aquifers involves the identification of an acceptable ultimate landward extent of the saline water body and the. Abstract the dispersion of salts produced by reciprocative motion of the saltwater front in a coastal aquifer induces a flow of salt water from the floor of sea into the zone of diffusion and back to the sea. The construction of canals that penetrate the floridan aquifer, deficient rainfall during 196475, and. Seawater intrusion and how to prevent it saltwater intrusion is the induced flow of saltwater into freshwater aquifers due to overdeployment of groundwater. Delineating zones of seawater intrusion in a coastal southern. The potential for saltwater intrusion in the potomac aquifers of the yorkjames peninsula, virginia by barry s. Where groundwater is being pumped from aquifers that are in hydraulic connection with the sea, induced gradients may cause the migration of salt water from the sea toward a well, making the freshwater well unusable. The intrusion occurs as a result of the induced flow of seawater into freshwater aquifers originally caused by groundwater development around the coast al barwani and helmi, 2006.
Freshwater stored in coastal aquifers is particularly vulnerable to degradation due. Abstract the dispersion of salts produced by reciprocative motion of the salt water front in a coastal aquifer induces a flow of salt water from the floor of sea into the zone of diffusion and back to the sea. Long distance seawater intrusion through a karst conduit. This study investigates into the parametric analysis on saltwater intrusion in a conceptual, coastal, unconfined aquifer considering wide range of freshwater draft and anticipated sea level rise. Heavy exploitation of coastal aquifers has effect on the hydraulic gradient. Saltwater intrusion ce le le fresh ground water fresh ground water ocean pumped well well discharge land surface saline ground water saline ground water a b figure 25. Largescale aquifer replenishment and seawater intrusion. Due to the lack of natural replenishment from rainfall and the excessive pumping, groundwater levels have declined significantly causing an intrusion of seawater in the coastal aquifer of wadi ham. Therefore, it can be affected not only by salt water intrusion, but by the salinization of its groundwater also due to other factors. Saltwater intrusion can naturally occur in coastal aquifers, owing to the. Saline water intrusion to investigate the degree and extent of saline water intrusion in the study area, the specific conductivity of the collected water sample are measured in terms of micromhoscm 3. Control of saltwater intrusion in coastal aquifers. Monitoring of saltwater intrusion in coastal aquifers.
The first is largescale, lateral flow into the coastal aquifer, the second is vertical upward flow, and the third is flow into the aquifer from coastal streams and canals, often forced by tidal movements. Delineating multiple salinization processes in a coastal plain aquifer. Chapter 20 coastal aquifer basin hydrogeology aquifer characteristics 492 hydrogeology aquifer characteristics aquifer configuration the coastal aquifer basin is a shallow, mostly consolidated, alluvial aquifer system with soil, dune, sand or loess alluvial as a cover. Seawater intrusion into coastal aquifers a case study. Saltwater intrusion in coastal aquifers waterloo hydrogeologic. Assessment of seawater intrusion potential from sealevel. Saltwater intrusion can occur when too much water is removed from wells and the groundwater is not able to recover. It makes the water from wells salty and undrinkable but some practices are able to prevent this. The sp gradient with depth indicates the close proximity of the saline front to the borehole and changes in sp at the borehole reflect changes in the location of the saline front. Mapping saline water intrusion into the coastal aquifer.
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