If 5 methods of preventing soil erosion(planting, munching, geotextile material, styrofoam wall, terrace farming) are tested, then the method with putting the cement wall on the soil’s surface will be the most effective because there will be almost no places for the water to seep into the soil.

           Introduction

Soil erosion is where soil from the topmost layer is worn away due to physical forces like wind, water, or glaciers. Wind or water slowly carves away soil and sand. For glaciers, it’s a bit different, as glaciers move very slowly but it can carry large rocks, by entraining, or picking them up..  The giant boulder in Okotoks was carried by a glacier. Wind from the sahara desert can carry sand and dust particles along the atlantic ocean, and as far as the amazon rainforest. Soil erosion will cause food shortages because as soil carries soil and nutrients from the ground, it decreases the soil fertility, which decreases production rates of many crops. It could also wash away the already existing crops, and again create food shortages. It also will cause rivers to become larger and stronger,as when soil and the plant roots living in it get washed away, the soil becomes looser and more soil gets eroded near the waterline. That repeats for years, and then the river expands without the “barrier” keeping it in. and with that, the animals living in the now non-existing soil also move away. Also, some places, like the hopewell rocks in New Brunswick, the soil/rocks there have been so eroded away that they created a unique landscape. The grand canyon, which is the longest canyon in the world, was created by the Colorado river slowly eroding the rocks and debris that was in the area.

       There are multiple ways that water can carry soil away. The first one is splash erosion. Water droplets can carry/scatter the soil as far as 60cm. Another one is sheet erosion, which is caused by runoff.a third one is rill erosion. It is caused by runoff, which will eventually lead to a small stream.Finally, gully erosion is where soil particles are carried off by big streams of water.

There are multiple ways to prevent/slow soil erosion. Some of them are:

       Planting crops

       One method is planting cover crops or other plants over the affected ground. A good example is a tree. How this works is that the roots keep the soil together. In farms, there are periods of time when there are no crops covering the ground, making it easier for soil erosion to occur. During those periods, farmers plant grass, and other stuff so the soil is covered.

       Mulching 

        Another method is placing pebbles or wood chips on top of the area, which is called mulching. This is usually only used in areas that are hard to grow plants, like near pines. This works like a cover/weight, not letting the soil escape.

       Geo-textile materials

       Another method is to put geo-textile fabrics on top of the area. These are basically woven fabric that have 2 or more materials in it. It usually has a boxy pattern, kind of like a blue sheet. There are 2 types, nonwoven and woven. The difference is, nonwoven materials are basically fibers or filaments combined randomly. Meanwhile, woven fabrics are fibers/filaments that are intertwined. This is usually used in farms to prevent soil erosion, but to let water in too. Some examples are polypropylene and polyester(PET).(5.)

       Cement walls

       In Japan, there are cement walls on cliffs and steep hills that prevent soil and other debris from falling into the houses and roads below. They have a blocky appearance, and are sturdy yet some were cracked.

       Terrace farming

       One final way is terrace farming. It is where the soil is cut up into boxy layers, kind of like stairs. This slows down the speed of the water, and prevents soil erosion. This is usually only done on moderate hills, and is hard to maintain on bigger ones. The steps are usually lined horizontally. This will help keep more water on the steps, letting more water infilter into the soil. Some examples of places that use this method are the Sa Pa terraces, which is in Vietnam. There, they grow rice, corn, and other veggies. Another location that you may know is Ollantaytambo, which is in Peru. It is famous for the Inca ruins, and the terraces start from the bottom of the valley to the top of the hills.(2.)

       Conclusion 

Each of the costs of the methods are like this:

Planting(for grass)-$0 to 20 cement wall- $10 to 25 per m2 

Mulching -$5 to 20   terrace farming- depends, at least $50 for the construction 

Geotextile materials- $45 to 90

The most common method is the planting, as it can be used basically anywhere.

Soil erosion is dangerous and could destroy whole landforms. It could also cause food shortages, causing many deaths. There are multiple ways to prevent soil erosion, but not all may be actually good. If it could fail easily or doesn't work easily, it could lead to wildlife getting destroyed, or people suffering. This experiment is very important to humans and animals, and it could maybe even save lives.

Manipulated Variable: The method on preventing soil erosion

Responding Variable:The amount of soil washed off

Controlled Variables : Temp of room (density/hardness of soil can change), Amount of soil, Amount of water, Angle of slope(speed of water), Duration of time the water is poured out(faster pouring will flood the method, and decrease its effectiveness)

control variables:Just soil

1. Set up all of the methods( planting, mulching, geotextile, wall, terrace) on 30 degrees slopes that are 30 cm long, with a catching device on the bottom( plastic bag or box, big enough to collect at least 200 ml of water(for styrofoam sheet, cut it up into 8 by 8 cubes)

• For the planting, prepare a couple of weeks before
• For terrace farming, do not add plants

2. Slowly sprinkle down 100 ml of water from the top of the slope over the course of 10 seconds(straight down)

       3. Filter the collected water with a coffee filter, record amount of soil caught(g)

       4. Repeat steps 3 and 4 for all methods

       5. Reset all of the methods

       6. Repeat steps 3-6 5 times

Quantitative data

Qualitative data

• For the styrofoam wall, most of the dirt carried away was from under the sheets.
• The geotextiles deflected most of the water down the slope.
• After a while though, the water seeped into the cloth and carried a bit of soil away.
• The terrace farming slowed down the water, so almost all of it was absorbed by the dirt.
• The mulching also slowed down the water, but not as much as the terrace farming.

methods vs methods

The averages and modes for each of the methods are:

• Planting… av=6 mode=6 and 5 -      Mulching… av=9 mode=none
• Geotextile.m… av=4.2 mode=4 and 5 -      Styrofoam… av=7.8 mode=9
• Terrace.f… av=3.6 mode=4

Of these 5, the method with the least soil eroded was the terrace farming. But, as the method with the second least amount of soil eroded,m which is the geotextile.m was less than 1 grams more, that method is about the same efficiency. Third place would be planting, and the average is about 1.5 times more than terrace farming and geotextile. The method with the second most soil eroded was the styrofoam, which eroded about 2 times more soil than the 2 first. Finally, the least efficient method was the mulching, with over 2 times of the soil eroded than the terrace farming.

methods vs control

The average of the control group was 39.6 grams.

Compared to the control group, the average of the geotextile material was almost 10 times more efficient. The terrace farming was 11 times more efficient, and planting was 6.6 times more efficient. For the mulching and cement wall, it was 4.4 times and 5 times. Overall, terrace farming was 1.1 times more efficient than the geotextile material, and the difference between the terrace farming and the mulching was over two times. 

If two methods were to be combined in to one, then the methods with the least soil eroded would likely by terrace farming and planting. If the 2 most efficient methods would be combined,it may not be good as while the terrace farming slowed down the water and absorbed it, the geotextile material sped the water up. The only reason the terrace farming got soil eroded was because the layers started to flood, and the water overflowing eroded the soil. The planting method could prevent the problem, as there would be more cracks in the soil for the water to filter into the soil.

In conclusion, the hypothesis was incorrect. The method with the least soil eroded was not the cement/styrofoam wall but they were the geotextile material and the terrace farming. The cement/styrofoam wall was the method with the second most soil eroded. 

There were a couple of flaws in the experiment. One of them were that the geotextile material that was used was not made for preventing soil erosion, and that the cement/styrofoam wall was not actually cement but was styrofoam. If the experiment was to be conducted again, cement and real geotextile materials will be used. Another weakness was that this experiment was conducted outside, so some of the water could of freezed.

Preventing or slowing down soil erosion will have many benefits for humans and animals.

 It will prevent food shortages because soil erosion decreases the soil fertility, and decreases production rates for crops. It could also save wild life, because soil erosion decreases soil fertility, and will kill plants. Then, there will be a chain reaction with animals. Also, soil erosion will kill animals in the soil, because they will lose their natural habitat. Some examples may be gophers, rabbits, and many types of insects. By planting trees and other plants, it will make more places for wildlife to thrive. 

There are a couple of places that would be recommended for uses of the methods. The first one would be places along the bow river that are either steep or doesn't have any vegetation. There, soil could be easily carried off  by runoff going into the river or the river itself. Since a lot of wildlife would live here, the methods that are recommended are planting or terrace farming. They both are not harmful to the environment, letting the animal and plant species living there still survive. Another place that is recommended for the methods are construction sites, such as the one beside deerfoot trail and near the IKEA. for those places, geotextile material would be recommended, as it would not impact the construction that much.

• There may have been slightly more or less soil in each trial.(by a few grams)
• There may have been slightly more or less water in each trial.
• The temperature may have affected the results.(it was cold outside)
• The experiment was conducted outside, so some of the water could of froze.(which could of acted sort of as a shield, preventing erosion of soil.)
• The soil may of been slightly more or less dense in some places/trials.
• Our cat ate some of the cat grass.

Grass Seed - Lawn & Grass Care. Grass Seed - Lawn & Grass Care - Homedepot.ca. (n.d.). https://www.homedepot.ca/en/home/categories/outdoors/lawn-and-garden-centre/lawn-and-grass-care/grass-seed.html 

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 https://education.nationalgeographic.org/resource/erosion/ 

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2.Kaplan, M. (n.d.). 11 incredible terrace fields around the world. Touropia. https://www.touropia.com/incredible-terrace-fields/ 

4.Reduce soil erosion. URI HomeASyst. (n.d.). https://web.uri.edu/safewater/protecting-water-quality-at-home/sustainable-landscaping/reduce-soil- 

5.Geotextile fabric: Uses and applications. Texdelta. (2021a, March 22). https://texdelta.com/en/blog/geotextile-fabric-uses-and-applications/#:~:text=Geotextiles%20are%2 

6.Woven vs. nonwoven geotextile fabric: What’s the difference? BlueStone Supply. (n.d.). https://bluestonesupply.com/pages/woven-vs-nonwoven-geotextile-fabric-major-differences-benefits 

7.Turito. (2023, July 20). Prevention of soil erosion - factors and effects of erosion. US Learn. https://www.turito.com/learn/biology/prevention-of-soil-erosion 

8.mckague, kevin. (n.d.). Soil erosion: Causes and effects. ontario.ca. https://www.ontario.ca/page/soil-erosion-causes-and-effects#:~:text=In%20agriculture%2C%20soil 

9.Mulvihill, K. (2021, June 1). Soil erosion 101. Erosion 101: Everything You Need to Know About Soil Erosion. https://www.nrdc.org/stories/soil-erosion-101

Thanks to everyone who helped me finish this project; Mrs. Burkell for setting the whole thing up, my teachers for helping me on the content, and my dad for helping me on the video. I also thank my family support me on this project.