Sand dunes investigation

Hypothesis 1

The further away from the beach, the lower the pH level.?

This idea is based on two key factors. The first reason is that the more away from the sea, the more vegetation there will be, and they normally lower the pH because they absorbed carbon dioxide in the air, causing them to become acidic. For the second reason, acidic land rainwater affects soil more when it is farther from the sea, but alkaline seawater has a greater impact on soil closer to the coast (Annex 2).

Hypothesis 2

The further away from the beach, the more vegetation covered.?

Based on the premise that more nutrients are available in the soil and the wind is weaker further away from the beach; thus, more vegetation can be found in the area. (Annex 2.) The strong onshore wind from the sea makes it harder for plants to grow closer to the coast. Because the soil along the coast is extremely alkaline, it is quite difficult for plants to thrive. Moreover

Hypothesis 3

The further away from the beach, the lower the infiltration rate.?

Because sand is the type of soil with a reduced infiltration capacity, meaning it is less water-absorbing, this hypothesis is founded on it. Therefore, the infiltration rate of sand is less than 30 mm/hour, which is a substantial amount for an area near the coast where there is a greater concentration of sandy materials. Clay has an infiltration rate of 1-5 millimeters per hour, indicating it takes longer for water to penetrate and more water is absorbed in the soil as it moves away from the seashore.

Geographical context

There are little ridges of sand known as dunes, which can be found near the top of beaches. It is an essential coastal feature that stabilizes the soil and acts as a protective barrier to protect inland areas from erosion and high-energy storms. With layers of strata forming and generating a land rich in vegetation that supports many lives, their formation of them is incredibly fascinating (Grey dune).

Dunes are formed by a combination of factors. Supply of sand with the correct grain size being the first. Sand must be available for deposition and tiny enough for it to be taken up by the wind. The second is a powerful wind that blows offshore. To create dunes (Grey dunes, for example), it is critical to shift beach emotions a distance inland. Finally, the dune must be stabilized by vegetation. Some other minor criteria are low gradient (so sands can deposit) and high tidal range (a large exposed area of the beach so there are sentiments available to construct dunes), (Grey dune).

Methodology?

In total, it took measurements every 4 meters along nine transects in the region. From the water at 0 m and measured up to 52 m distant (4 out of 9 transects were unable to reach 52 m) for each transect (Khechekhouche, 2020). All nine transects were divided among the three groups, with each measuring three of them.?

Results analysis?

Using the Logger Pro website,?it?plotted the data for each hypothesis. You can see if the?hypotheses were confirmed by the data by examining the line of best fit and the two-way correlation value calculated by the website (Bateman, 2018). The values create a U shape when combined, which goes against my theory because the relationship is not linear. Both of these tendencies can be seen. To see if each part of the graph exhibits the correct trend, it?wants to separate the two sections.

A correlation of -0.3052 between the two portions supports the hypothesis, whereas a correlation of 0.4075, which is much larger, shows the full opposite trend. Consequently, my theory has been disproved. According to the data, the opposing correlation appears to be more accurate, even if it has not been confirmed to be correct (Bateman, 2018).

Each transect is markedly different from the others because two distinct trends were generated by two distinct groups of individuals. pH probes or human errors may be to blame for the discrepancies. As a result of the systematic error between pH transect average values, the difference between each transect average value can be up to 2, which is a significant amount for pH values and can indicate a percentage mistake of up to 50%. (Graphical Analysis with Logger Pro).

In addition to any systematic problems, pH levels can be altered by the typhoon that passed the day before we gathered data. The soil where we tested pH contains both sand and sandstone. Unlike sand, which is normally alkaline (with a pH of 3), limestone, which is calcium carbonate, has a pH of over 7. The powerful winds brought on by the typhoon may cause sandstone and sand to develop in unexpected places (Khechekhouche, 2020). A decrease in the pH difference between soils near the sea and soils farther away from the sea due to the movement of sand and sandstone could induce a trend in pH that it hadn't anticipated (wind gradient). When all nine transects' data is considered (Graphical Analysis with Logger Pro).

There is a weak association between vegetation cover and distance from the land when fitted with a linear model, with a correlation value of just 0.2014. (Lancaster and Nicholas, 2013). Despite this, more than half of the transects had a correlation value greater than 0.5, which indicates that the vegetation cover and distance from the sea are strongly correlated. Due to a negative correlation in one transect, the overall relationship between all of the values isn't clear. However, correlation values as high as 0.9016 across all transects back up my idea.

Using graphical analysis with logger pro, it?can seem that some transects extend to places with less vegetation than others, which helps explain the correlation anomalies. It can also be the quadrat method of determining vegetation cover, which has a range of probabilities. Because we only conducted one trial, the vegetation cover we assessed may differ significantly from the average vegetation cover in the region we examined (Lancaster and Nicholas, 2013).

When all the data is taken into account, there is only a slight positive link between soil infiltration rate and distance from the sea.

?However, only three transects in each set exhibit a significant association, and the other two show an erroneous correlation, namely a negative correlation and no correlation at all (with a correlation value of 0). Although the highest correlation value is 0.9306, my hypothesis is not supported, even though the correlation value is 0.9306. (Graphical Analysis with Logger Pro). Some factors may have an impact on the outcome. As a result, water infiltration is reduced, which has a negative impact on the environment. Considering that the soil was more likely to absorb a large amount of rainwater due to a typhoon passing through earlier that week, this effect may be amplified (Lancaster and Nicholas, 2013). This is why it's better to collect data in sunny conditions to get the most accurate results.

Conclusion?

As we moved away from the coast, most of the data we recorded didn't change significantly, but the soil color darkened and the vegetation grew in size.

As can be seen in the graph, wind speed does not appear to have a clear association with distance from the sea (Bateman, 2018). This may be due to the ocean's relatively smooth surface, which reduces wind speeds closer to the sea less than land does. The reduction in velocity near the surface is a function of surface roughness.

Wind speed does not diminish with distance from the sea, which explains why could not see a significant association between vegetation cover and distance. If the wind speed in more inland places remains relatively constant, vegetation will not be able to thrive there. The composition of the soil, which includes sand, sandstone, and clay, affects the rate of infiltration and the acidity of the soil. As you move away from the coast, the clay in the soil may not change significantly. Sandstone and clay deposition is still very unlikely in inland areas because of high wind speeds. This means that the soil has the same composition of elements, which is mostly sand. This study has several advantages and disadvantages. Because each group had at least four people in it, we were able to reduce random mistakes because we were able to assess more trials. This is a positive aspect of the study, as it provides students with a good amount of data. In contrast, data gathering has some flaws, such as bad weather and small sample size, that make it difficult to show trends on a larger scale. Measurement can be improved if it is possible to take place during a period of generally sunny weather because of the impact of the typhoon that passed the day before. We can also measure more than nine transects, each measuring more than 48 meters long away from the sea, and we can measure throughout the course of more than one day to improve the problem with mistakes. To see if the trends revealed in the data are constant across different weather conditions,?would need to collect data over a longer period. In this way, the findings will be more applicable to a beach setting as a whole.

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References

Annex 2 Infiltration rate and infiltration test

https://www.fao.org/3/S8684E/s8684e0a.htm.

Bateman, M. D., Rushby, G., Stein, S., Ashurst, R. A., Stevenson, D., Jones, J. M., & Gehrels, W. R. (2018). Can dunes be used to study historic storm events?.?Earth Surface Processes and Landforms,?43(4), 779-790

Grey dune, Wikipedia

https://en.wikipedia.org/wiki/Grey_dune#:~:text=These%20dunes%20are%20 typically%20locate d,top%20soil%20layer%20of%20humus.

Graphical Analysis with Logger Pro - Bellevue College

https://www.bellevuecollege.edu/wp? content/uploads/sites/140/2014/06/Logger-pro-activity.pdf

Khechekhouche, A., Benhaoua, B., Manokar, M., Sathyamurthy, R., Kabeel, A. E., & Driss, Z. (2020). Dunes affect the productivity of a single slope solar distiller.?Heat and Mass Transfer,?56(4), 1117-1126.

Lancaster, Nicholas, (2013),?Geomorphology of Desert Dunes, Routledge, London, The United States.

Wilshire, H., and Webb, H., (2012), Environmental Effects of Off-Road Vehicles: Impacts and Management in Arid Regions,?Springer Science & Business Media, Berlin, Germany.

"Wind gradient - Wikipedia." https://en.wikipedia.org/wiki/Wind_gradient.