IB Geography Internal Assessment: Standard Level
Examining the Rate of Coastal Erosion in Areas with Hard
Engineering versus Areas with Hard Engineering
Research Question: To what extent are engineered seawalls effective in minimizing the rate of
coastal erosion compared to natural shorelines in Escambia Bay in Pensacola, Florida?
Hypothesis: Engineered sea walls will produce a higher rate of coastal erosion than natural
shorelines due to the reflection of wave energy back into the water, resulting in a greater rate of
erosion and beach loss. Additionally, there will be a lower population density and beach berm
length than the natural shoreline.
Candidate Number: 471755
Word Count: 2,153
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Table Of Contents
Examining the Rate of Coastal Erosion in Areas with Hard Engineering versus Areas with
Hard Engineering
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Table Of Contents
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Criterion A - Field Work Question and Geographic Context
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Criterion B - Method(s) of Investigation
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Criterion C - Quality and treatment of information collected
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Criterion D - Written analysis
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Criterion E - Conclusion
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Criterion F - Evaluation
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Bibliography
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Criterion A - Field Work Question and Geographic Context
Research Question: To what extent are engineered seawalls effective in minimizing the rate of
coastal erosion compared to natural shorelines in Escambia Bay in Pensacola, Florida?
Hypothesis: Engineered sea walls will produce a higher rate of coastal erosion than natural
shorelines due to the reflection of wave energy back into the bay, resulting in a greater rate of
erosion and beach loss. However, natural shorelines will be able to produce less coastal erosion
with a shorter beach berm and higher population density.
Geographic context: This investigation was carried out in the Otis Landing and Chimney Park
area in Pensacola, Florida, both strips of shoreline near the Escambia Bay Bridge that connects
Pensacola to the city of Milton, where the coastal management systems deployed are engineered
sea walls and natural shorelines. These areas were chosen for investigation since the areas are
one of the few shorelines open to the public. In contrast, the majority of the shoreline is private
property for homeowners, which severely limits the accessible areas for fieldwork to take place.
Despite the setback of accessibility, this shoreline contained the ideal aspects relating to the
question’s demands such as seawalls, vegetation, fluctuating wave energy, and beach berms,
which will all be used to identify if engineered sea walls are more efficient in preventing coastal
erosion compared to natural shorelines.
Pensacola is a part of the northwestern region of Florida, with Escambia Bay serving as
an outlet to connect into Pensacola Bay, which then bleeds into the Gulf of Mexico, which is a
hotspot for hurricane vulnerability and subsequent flooding and accelerated rate of erosion.
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Figure 1: A map of the United States, with Florida and Pensacola indicated.
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Figure 2: A map depicting the location of Pensacola in Florida.
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Figure 3: A map depicting the general location and area of Escambia Bay.
Figure 4: A high-definition map pinpointing the locations of Otis Landing and Chimney
Park.
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Figure 5: A higher definition map of the engineered seawalls in Otis Landing.
Figure 6: A higher definition map of the natural shoreline in Chimney Park.
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Figure 7: A close-up shot of the engineered sea walls in Otis Landing.
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Figure 8: A close-up shot of the natural shoreline in Chimney Park.
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Figure 9: Sediment Collector Deployed On Otis Landing Area; Engineered Seawall
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Figure 10: Sediment Collector Deployed On Chimney Park Area; Natural Shoreline
Relationship to Geographical Theory: The research presented relates to the coastal protection
strategies of engineered sea walls and natural shorelines, which are designed to reflect wave
energy and minimize the rate of erosion. When discussing coastal erosion, it is the process of
carrying away rocks and sediments. Wave energy refers to the overall strength of the waves that
crash along the coastline. Both factors have an interconnected link as the higher the wave energy,
the higher the rate of erosion occurs. With this concerning issue, coastal management systems
were instilled along coastlines to minimize the rate of erosion using two engineering techniques.
If man-made physical structures are used to manage natural processes such as erosion and
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flossing, it's hard engineering. Soft engineering serves as its antithesis as defined by the usage of
natural structures and objects to prevent pre-established concerns, such as rocks and vegetation.
For this investigation, the engineered sea walls are categorized as hard engineering and natural
shorelines as soft engineering.
Relationship to IB syllabus topic:
The investigation presented in this paper relates to the IB Geography Guide as it is based
on the Option B: Oceans and Coastal Margins section of the IB syllabus and addresses the
“Interactions between oceans and coastal places” subcategory. My investigation correlates to this
topic since engineered sea walls and natural shorelines absorb and reflect back the wave energy
to minimize the rate of erosion, which correlates to “How coastal places are shaped by their
interactions with oceans” and demonstrates a clear relationship between the interactions between
the coastal management systems and Escambia Bay.
Criterion B - Method(s) of Investigation
Method(s) of Investigation:
When measuring the rate of coastal erosion, it is imperative that the right devices and
methods are employed to measure its extent for prevention effectively. In this procedure, two
devices were deployed in Otis Landing and Chimney Park for sediments and other materials
vulnerable to coastal erosion. After the sediment collection section, the device’s contents will be
released onto a container and weighed on a digital scale. If the sediments present a greater mass,
this would suggest that the coastal management systems of engineered sea walls or natural
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shorelines are ineffective in their function of minimizing the rate of coastal erosion. Additionally,
the absorption of wave energy is a vital factor that will be accounted for via measurement of the
beach berm, the ridge of sand that indicates the amount of wave energy present in the area
Throughout November to January, data was collected throughout five trials on November 14 and
26; December 11 and 23; and January 16 during various times.
Criterion C - Quality and treatment of information collected
Table 1: Date and Time of Trials Conducted at Each Location
Otis Landing
Chimney Park
November 14, 2022
4:16 P.M
4:57 P.M
November 26, 2022
3:08 P.M
4:12 P.M
December 11, 2022
11:19 A.M
12:02 P.M
December 23, 2022
7:18 P.M
8:07 P.M
January 16, 2023
5:19 P.M
6:04 P.M
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Table 2: Measure of Sediment Collection in Both Locations (grams)
Otis Landing
Chimney Park
(Sea Walls)
(Natural Shorelines)
Trial 1
86g
109g
Trial 2
64g
104g
Trial 3
81g
92g
Trial 4
76g
117g
Trial 5
87g
94g
Average
80.2 g
103.2
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Table 3: Measure of Beach Berm In Both Locations (length: meters)
Otis Landing
Chimney Park
(Sea Walls)
(Natural Shorelines)
Trial 1
2m
5m
Trial 2
1m
3m
Trial 3
4m
7m
Trial 4
2m
8m
Trial 5
1m
8m
Average
2m
6.6m
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Table 4: Number Of People Near Both Locations
Otis Landing
Chimney Park
(Sea Walls)
(Natural Shorelines)
Trial 1
15
3
Trial 2
3
2
Trial 3
6
5
Trial 4
11
7
Trial 5
6
1
Average
8.2
3.6
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Figure 11: Comparison of Sediment Collection (grams)
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Figure 12: Comparison of Beach Berm Length (meter)
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Figure 13: Comparison of People Present in Both Locations
Criterion D - Written analysis
Data Analysis: Chart 1 presents the comparison of sediment collection between sea walls and
natural shorelines. Otis Landing, the site of the engineered sea wall, accumulated 86, 64, 81, 76,
and 92 grams of eroded soil whilst Chimney Park collected 109, 104, 92, 117, and 94 grams of
sediment in its living shoreline. Based on the varying data presented from both locations, there is
a grand quantifiable difference in the masses of the eroded soil, implying that the engineered sea
wall at Otis Landing was less effective in protecting the shoreline as opposed to the natural
shoreline at Chimney Park.
In Chart 2, the data shows the comparison of the beach berm lengths between the sea wall
and the natural shoreline. Throughout the 5 trials in 3 months, Otis Landing exhibited lengths of
2, 1, 4, 2, and 1 meter whilst Chimney Park displayed lengths of 5, 3, 7, 8, and 8 meters. The
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data appears to be relatively consistent, with minimal deviation from the mean, implying that
beach berms tend to be longer in natural shorelines as opposed to sea walls.
In Chart 3, the data shows the comparison of people present in both locations. In Otis
Landing, there tends to be a higher increase in residents and civilians alike whilst Chimney Park
remains sparse in its people. This disparity can likely be attributed to the presence of a large
population of coastal homes near the engineered sea wall as compared to the natural shoreline.
This implies that the sea wall serves as the primary coastal management system for the
protection of coastal buildings and houses from flooding and erosion, which may be a
contributing factor to the higher population density in the vicinity of the sea wall. Overall, it
appears that more people are located nearer to the sea walls than natural shorelines, making sea
walls the more favored system.
According to the data collected via the coastal erosion collecting device, there was a
significant difference in the amount of eroded sediment collected between the engineered sea
wall in Otis Landing and the natural shoreline in Chimney Park. Specifically, there was an
average of 23 more grams of eroded sediment collected in the natural shoreline than the
engineered sea wall. This data suggests that while the natural shorelines may be a more
environmentally sustainable and financially efficient coastal management system, they may not
be as effective in preventing coastal erosion. Additionally, the data shows that the length of the
beach berm within the natural shoreline in Chimney Park was, on average, 2.2 meters longer than
the beach berm in the engineered sea wall in Otis Landing. This suggests that the natural
shoreline is more effective at dissipating wave energy and protecting the shoreline from erosion.
Furthermore, the data indicates that there is an average of 4.6 more people located near the
engineered sea wall in Otis Landing than the natural shoreline in Chimney park. This may
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suggest that the sea walls are a more popular coastal management option due to the sense of
protection they provide against erosion. In conclusion, while natural shorelines may be more
environmentally sustainable, the data suggests that they may not be as effective in protecting the
shoreline from erosion as engineered sea walls.
Written Analysis: The data collected during the five trials displays that, on average, the
engineered sea wall at Otis Landing had 23 more grams of eroded sediment than the natural
shoreline at Chimney Park. The data indicate that while natural shorelines may be more
environmentally sustainable to build, they may not be as effective in preventing coastal erosion
as engineered sea walls. Additionally, the data shows that the beach berm within the engineered
sea wall at Otis Landing has a 4.6 m shorter average than the natural shoreline. This suggests that
while engineered sea walls may not be as effective at absorbing wave energy as natural
shorelines, they still tend to have a lower rate of coastal erosion. Overall, the data implies that
while natural shorelines may be deemed more favorable for the environment and the budget of
Pensacola, they may not be as effective as engineered sea walls in preventing coastal erosion.
Therefore, the data collected refutes the initial hypothesis and provides evidence that engineered
sea walls will have higher rates of coastal erosion compared to natural shorelines with a longer
beach berm and shorter population density.
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Criterion E - Conclusion
The fieldwork and data collected effectively addressed my research question and
provided insights into the relative effectiveness of engineered sea walls and natural shorelines in
preventing coastal erosion. However, the results of the study refuted my initial hypothesis that
engineered sea walls were less effective in preventing coastal erosion, with longer beach berms
and a lower population density. My initial hypothesis was that engineered sea walls would
produce a higher rate of coastal erosion than natural shorelines due to the reflection of wave
energy back into the water, leading to greater rates of erosion and beach loss, as well as a lower
population density and shorter beach berms. However, the data collected from sediment samples,
beach berm measurements, and population counts provided strong evidence that natural
shorelines were less effective in preventing coastal erosion than engineered sea walls, thus
refuting my hypothesis. The factors that invalidated my hypothesis were the significant
quantifiable differences between the two coastal management systems for each variable. The
engineered sea wall had an average of 80.2 grams of eroded sediment, which was 23 grams less
than the natural shoreline. Additionally, the average beach berm length on Otis Landing was 4.6
meters shorter than that of the natural shorelines, with an average of 2 meters. Lastly, the
population density average near the engineered sea wall was 8.2 people, which was 4.6 people
more than that of the natural shoreline. These results suggest that engineered sea walls are
actually more effective coastal management systems in preventing coastal erosion than natural
shorelines, despite their lack of environmental sustainability.
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Criterion F - Evaluation
In an experiment where massive amounts of fieldwork and data have to be conducted, it
would be largely beneficial to have as many trials as possible since it would further validate the
strength of the evidence that is supporting the proposed question and hypothesis. During this
investigation, only five trials were able to be conducted since these locations were one of the
only publicly available shorelines in Pensacola, which are also located relatively far from the rest
of the city. Additionally, the weather in Pensacola greatly fluctuates between sunny and rainy
days, resulting in potentially skewed results since flooding greatly affects the shorelines.
Consequently, resulting in greater rates of coastal erosion between trial dates. If the locations
presented greater availability to the public, more trials would be conducted and provide stronger
data. However, these trials were carried out to the best of their ability as the varying dates and
times reflect the distance traveled to travel to each location.
This experiment made great use of measurements when measuring the mass of eroded
soil on the shorelines, the lengths of the beach berms, and the counting of people nearby the
location. However, measurements could potentially have been inaccurate due to human error.
When weighing the sediment collected, there is a ±1 uncertainty on the digital scale, which could
greatly impact the results of the actual sediment collected. Furthermore, there remains additional
human error when measuring tape was deployed for extracting the lengths of the beach berms
and the counting of people nearby. In order to minimize these problems, precision was made a
high priority when deploying the sediment-collecting device in the water, planting the measuring
tape on the beach berm, and carrying a tally sheet to count the exact people in the area.
The sediment-collecting device provides a few key limitations regarding its ability to
catch bigger sediment sizes like rocks, which could have potentially been used to measure the
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rates of coastal erosion as well. However, this would skew the results of the sediment mass
collected and end up being cut from the investigation. Furthermore, the sediment collecting
device was placed at the edge of the shoreline. As it collects water and sand, the device could
potentially have been shifted in any direction due to the movement of the waves. To prevent
shifting, a string was attached to the bottom of the device to keep it in a fixed location with
minimal swaying.
Overall, this investigation was an extensive and elaborate process as it presented various
skills of data collecting and minimizing human error. The fieldwork question was endured to
include specific details that were linked to both the IB syllabus topic and quantifiable to present a
conclusion that would produce a concussion on the most affecting coastal management system.
Although there were strong difficulties and errors presented, the data still was conclusive, and
my hypothesis, though wrong, provided a stronger understanding of the functionalities of
engineered sea walls and natural shorelines.
Bibliography
1. International Baccalaureate. Diploma Programme Geography Guide. Geneva,
Switzerland: IB, 2017. Print.
2. https://www.arlis.org/docs/vol1/234196545/pensacolabay.pdf
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