Investigating the Rate of Seawater Intrusion Into Freshwater
Over the next century or two sea levels are rising and increased frequency of extensive natural disaster caused by global climatic change bring about serious issues. This issue is going to fall on lower-lying coastal and riverside areas. This has to lead to these areas to investigate and implement the way to produce a truly sustainable city.
Saltwater intrusion is the landward movement of seawater. This occurrence has many consequences on coastal ecosystems and communities versus the flooding impacts of sea level rising. This intrusion often occurs as part of the daily tides. Research has been done documenting the increase in flooding due to large storms and higher tidal inundation because of higher sea level and this, in turn, affects the water supply in private property and the ability to provide fresh water for drinking. In order to have fresh drinking water, many people depend on deep wells or reverse osmosis to filter out the salt. The process of seawater intrusion alters the ecosystem leading forested wetlands to become brackish water wetlands. Adaptation to climatic risks can be hindered by the lack of information shared about this issue. And in many cases, financial constraints play a major role. It may take incentive programs to get everyone on board for implementation of needed changes as the needs and benefits are different than private and business (Tully et al, 2019).
Importance of studies for freshwater preservation
In most coastal areas in the US, residents rely completely on groundwater for freshwater. Thirty-nine percent of the population in the US is found living along the coastlines. Since they have been pumping the coastal aquifers nearly dry. They run the risk of saltwater getting into these empty spaces. Nature hates a vacuum and saltwater is a real potential if this practice is continued without checks and balance. This issue could become a life or death proposition for residents as these coastal areas have less and less fresh drinking water. There needs to be put in place regulation of the removal of freshwater to decrease seawater encroaching into the gap. In the upper area of Florida, the scientists have already begun to have difficulty with saltwater inclusion. The research was done and it appears part of the issues is controlled in part by the daily tides. Monitoring of wells in Florida and Georgia has documented the influence of the tides and precipitation has on the intrusion of saltwater. With each hurricane season the potential for the disruption of the groundwater and saltwater increases. Further research needs to be conducted and quickly to help retain drinking water without the need to use desalination (Williams, 2019).
Around the world, many coastal areas are suffering extreme freshwater stress due to poor management of available water resources. Many recent studies have been accomplished showing these coastal areas how if they don’t limit some of their use of the groundwater can lead to saltwater intrusion into the groundwater. This includes the typical well and its rate of salinization. It is this reason that governments need to address this issue to manage water resources. The Judea group aquifer is losing a continuous loss of level due to pumping out of the water. This study shows the direct impart pumping of groundwater aquifer on salinization of those same aquifers. The most important outcome of this study was it showed the correlation between drawing down the level of wells and the occurrence of salinization of those wells by saltwater intrusion (Palidor, Shalev, Katz, & Aharonov, 2019).
We are not the only ones affected
World wide aquifers located in low-lying coastal areas are threatened by saltwater intrusion. This article shows not just the history of groundwater that is affected by saltwater intrusion and possible methods to limit this intrusion in an effort to preserve fresh drinking water. There has been a study of 70% of coastal areas where drains control groundwater level the saltwater inclusion is greater. In some areas an effort has been made to decrease the effect of the tides; they have erected a flood gate to limit the amount of ocean water during high tide. By making use of geophysical and hydrogeochemical data the mechanism of saltwater intrusion is better understood. But it is important to realize even though there has been some promise shown with models there needs to be closer look and further research. An example is that a sloping seabed can be influenced in keeping seawater intrusion at a minor amount. And the article reports there are needs to not only replicate their research to validate what they found but to further the research into ways to protect freshwater for drinking (Meyer, Engesgaard & Sonnenborg, 2019).
This study has used an unusual method to attain information about seawater inclusion. They took care of this making use of AEM (airborne electromagnetic) data. This data found great strides invaluable information about water quality in the offshore aquifers. This is important as roughly 40% of the global population live within 328 feet of the coast. The process used to measure seawater inclusion is to test drinking water wells. And while there is some difficulty in obtaining the intrusion point due to the conductibility of seawater on the surface AEM still is very effective. AEM could show the depth beneath seawater depth up to 59.1 feet. AEM was able to determine the interface between seawater and freshwater. They concluded that AEM is a useful tool in mapping and monitoring seawater intrusion (Goebel, Knight & Halkg, 2019).
In an effort to produce freshwater this research has been conducted by Monash University. In this study, they determined there are about 844 million people that don’t have access to clean water. Seawater desalination and recycling of wastewater are two ways currently being used to help reduce the stress on natural aquifers. This research has shown it is possible to provide drinkable freshwater by making use of photothermal materials and the power of the sun. this object can provide clean drinking water in a continuous and efficient manner from seawater; had nearly all saline gone. This was tested off the shore of Australia and offers hope to areas with very limited clean drinking water (Monash University, 2019).
Goebel, M., Knight, R. & Halkjær, M. (2019). Mapping saltwater intrusion with an airborne electromagnetic method in the offshore coastal environment; Monterey Bay. Journal of Hydrology: Regional Studies, California, 23(100602).
Meyer, R., Engesaard, P. & Sonnenborg, T. (2019). Origin and dynamics of saltwater intrusion in a regional aquifer: Combing 3-D saltwater modeling with geophysical and geochemical data. Water Resources Research,55(3).
Monash University. (2019). Water solutions without a grain of salt. Monash University Department of Chemical Engineering.
Nakajima, T. & Umeyama, M. (2019). And integrated floating community based upon a hybrid waster system: toward a super-sustainable water city. WCFS (world conference on floating solution), pp 309-328. Abstract.
Paldor, A., Shalev, E., Katz, O. & Aharonov, E. (2019). Dynamics of saltwater intrusion and submarine groundwater discharge in confined coastal aquifers: A case study in Northern Israel. Hydrogeology Journal, 27(5).
Tully, K. et al. (2019). The invisible flood: The chemistry, ecology, and social implications of coastal saltwater intrusion. BioScience, 69(5).
Williams, M.D. (2019). Controls on saltwater intrusion in a shallow coastal aquifer: Wormsloe Historic site GA. Thesis submitted by author to Georgia State University Department of Geosciences.