An Analysis of Seawater Intrusion in Coastal Aquifers

I examine how rising or falling tide can affect the water level of Corte Madera Salt Marsh in this report. The data is from Wednesday (June 19th) and Thursday (June 20th). My hypothesis is that tide and water level have positive relationship. From the result, I learn that the water level and tide have positive relationship. However, when tide changes its direction, the water level is likely to stay or little change.

Carefully read Ch. 12 of Geoscience Laboratory. Pay special attention to the graphs and figures.

For the saltwater plumes, a saltwater plume is a horizontally moving body of saline fluid that is contained in the larger, fresh body of water. The plumes come about when there is heavy retraction from the aquifers resulting in a saltwater intrusion. In order to keep the plume from reaching any of the retraction sites, or wells, we must keep a close eye on the pumping amounts at each well. For instance, Georgia Pacific shuts their machinery down for two weeks every summer, this causes the plume to shift from the middle of two well sites to the well site being used the most. This can cause the quality of the water to lessen as the taste will become salty and bitter. While there is an unlimited supply of water coming from the aquifer, the rate at which the water is being retracted can cause the water to become tainted with plumes, among many other problems and

Saline intrusion is the movement of saline water into freshwater, which can lead to contamination of drinking water sources and other consequences. This is a serious issue that we face today, but with the right actions the public can put an end to it. Salinization on the coast can lead to the increase of sodium ions in soil and water. This is important because high salt levels can affect osmosis, the process by which some organisms, such as plants, take up or give away water. As the number of salt ions in the surrounding environment increase, water will flow out of an organism towards the higher concentration, causing dehydration and death (Molly Webster, 2007).

Currents under the sea play an important role in the formation of a coastline. Currents may be generated by density differences in water masses caused by temperature and salinity variations (NOAA, 2013). These currents move large water masses through deep ocean taking nutrients, oxygen, and heat with them (NOAA, 2013). However, some currents are affected by other variables such as huge storms that move water masses, underwater earthquakes that may also trigger tsunamis (NOAA, 2013). Both types of variables move masses of water inland

Sedimentation: The settling out of suspended particles from a body of water (or in some cases, very fine particles settled from the air or blown by the wind).

By the last parts of the presentation, the speaker talked about the impact of saltwater intrusion and the changes that it brings about in soil properties, microbial community and plants. He later exposed his own results, their research sites and how their outcomes differed in each of these places. He pointed out that the ecosystems in Cumberland (Virginia) and Brookgreen (South Carolina) responded somehow differently. Nevertheless, he emphasized that in areas of saltwater intrusion, the ecosystem growth was inhibited to some extent.

Salt water intrusion is the movement of saline water into freshwater aquifers. Changes in the climate and sea level drives changes to the coastal groundwater system, which affects the public groundwater supply wells. A study on the impact of sea level rise on saltwater intrusion

The Saco-Casco Bays coastal inundation model (Figure 1) is based on FVCOM 2.7 and includes tidally driven flooding and drying of intertidal areas [3].The model is based on free-surface primitive equations, finite volume schemes, flux-based and resolves integral form of the governing equations by second-order [4]. The momentum and continuity equations of the inundation model are closed by the Smagorinsky turbulence scheme [5] for horizontal, furthermore the Mellor

The transient simulation was carried out to simulate the behavior of the aquifer in response to climatic change in the dry period after decreasing the infiltration rate with the end of the last wet period (~10,000 yr BP). The calibration in this stage was used the groundwater contour lines measured by Ball (1927) and Sandford (1935) which represents the groundwater level in the aquifer before beginning of the heavy exploitation in 1960 neglecting the very low decline in the water level between 1935 and 1960 in comparison to the long period between 10,000 BP and 1927 or 1935

Palomar, P & Losada, IJ (2010), Impacts of Brine Discharge on the Marine Environment. Modelling as a Predictive Tool, Desalination, Trends and Technologies, pp. 279-310.

The study comparing salinity and dissolved carbon dioxide indicate that there is a significant correlation between them. This is due to both regression tests in the field showing a negative correlation between the two values, and the lab conducted in class showing saltwater to diffuse less carbon dioxide and freshwater. Therefore this study confirms that the level of dissolved carbon dioxide in water is inversely proportional the salinity of that water.

The density of ocean water is not the same throughout the global oceans, but varies significantly and discretely. Warm seawater expands and is therefore less dense than cooler seawater. Moreover, saltier water is denser than fresher water because of the dissolved salt that fills the space between water molecules, resulting in greater

The two types of salts that were deposited on the floor were Halite and Gypsum. Some of the salt deposits were as deep as 800 meters which is equivalent to 2,500 feet. The scientists were baffled by this discovery, thus leading to numerous investigations about where these salt deposits came from. Some of the scientists believe that environmental changes like the Mediterranean Salinity Crisis, could quite possibly have a larger affect than what is assumed. Scientist believe that it could having an impact on the global level.

Porosity of the aquifer is immensely important as the holes in aquifers such as sandstone and fractured limestone, need to be big enough to allow water to flow through (Lutgen & Tarbuck 2011). However, although the permeability of the aquifer and the ground is very important, the holes that allow water to go through in order for the aquifer to be useful cannot exceed a particular size either. If the aquifer is too permeable, too much water will flow through too quickly, and the well that uses the aquifer will dry out; this is because the rate at which the water is being used is faster than the rate at which the water can be replaced (Lutgen & Tarbuck 2011). The numbers of small pores in between the aquifers are important for filtering the water as well. The smaller the holes in the aquifers are, the more bacteria that can be filtered therefore preventing these bacteria from reaching and endangering people. However, the size needs to be big enough for the water to flow through so that the water does not clog and have