What else could go wrong when the environment interacts with the environment?

Nature is beautiful, amazingly unique, and awesomely vibrant. Yes she is, but sometimes, a lot of things can seem to “go wrong”. And cause some unpleasant occurrences as we are aware of today. Many of these times however, human factor is also present as the causative or sometimes, negligence is the issue. Something seems to be going wrong around us but we sort of take our eyes and/or mind off it and we pretend not to see it and that goes on until the issue gets out of hand. Well I expect you to have an idea of what I’m talking about, let’s go on.

Since I was born (and even years before then), I have always known that the earth is spherical (flat earthers, please keep off) and hasn’t changed or has it? Well, looking at the earth from space (if you have ever been to space or with the aid of satellite images all over the internet) the shape has actually been the same but a little close and personal, the surface of the earth (the land surface to be precise) has been changing over the years. What has been the cause of this change? Wait a little while.

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I would like to tell a story, as a matter of fact a sad one.

I was born (and still live) in one of the sub-urban areas in Lagos, Nigeria – Ikorodu. A beautiful area it is but one specific characteristic of it is the untarred roads and little or no drainage system. As a result of these, whenever it rains, there is always a massive movement of water (flood) and as some part (especially the road leading to my street) are quite steep, the water gets to make an impression as it moves in large numbers (I didn’t count) down the sloppy road.

I expect you to know the result of moving water on a sloppy untarred road. This left the road in a pretty bad shape – made it sloppier and made it only motor able on one side. As a result of this, climbing or descending the sloppy road would take one vehicle at a time. On a fateful day after a fairly normal rainfall accompanied by the ”normal” flood, I was walking home from school and as soon as I reached the top of the sloppy road at the beginning of my street, something happened. A truck trying to ascend the slope lost its brakes and literally raced downward.
Because all vehicles are on one side of the road, a lot of vehicles which were following closely behind were crushed and damaged and even it resulted in the loss of a life.

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A sad experience it was and what made me remember even till now is the fact that ii walked past the truck just moments before the incident occurred. Who could have known what would have become of me if I stayed a little longer admiring the big wheels of the truck as they rolled past?
As I grew older, I realized that the accident can only be blamed on the bad nature of the road as a result of erosion and folks, that is what we would be discussing today – EROSION!

This gradual looming danger is not a good sight (image taken by me @rharphelle)

In my last three posts, I talked about a phenomenon that is common to metals in the environment – corrosion and this only occurs when the metal reacts with its environment. Well, have you taken some time to ponder about what happens if the environment interacts with the environment? Tricky question you might say but in the real sense of the world, it’s not tricky at all, in fact, it is one common thing that happens everywhere.

There are some slight similarities between corrosion and erosion, the first and most obvious one being that they are both spelt with “-sion” ending their words (lol). The two phenomena involve the depletion of the surface of a material as a result of the actions or interactions with an external factor. On the flip side, corrosion and erosion are quite different in the sense that corrosion occurs mostly as an (electro)-chemical process while erosion is mostly physical. I wouldn’t want to bore you with another corrosion talk, I have already done something on that subject in the previous posts.

The subject of erosion is not a new or somewhat “strange” subject sincerely but its impact in shaping our earth (in terms of land mass) cannot be overlooked. If left without caution, it will result in catastrophic results. So, let’s take a critical look at the subject matter – erosion.

Erosion is simply the gradual removal and transport of particles from the surface of the earth as a result of relative movement of external forces. Forces such as water, wind and ice are the culprits responsible for erosion. However as soothing as this may sound, human factors also have a big role to play in the process of erosion.

The process of erosion is quite a simple one, the forces (water or air) move relative to the earth surface and as a result of their relative motion against the earth surface, they break off particles and carry them along their path to be deposited somewhere else. Simply, that means, when a place is being eroded, another place is getting deposited (does that look like galvanic corrosion?). A very similar term to erosion is weathering. While some people might think erosion and weathering are the same, they actually are not.

A similar process, weathering, breaks down or dissolves rock, but does not involve movement. _source

Look at it this way; you take a small rock and you hit it with a hammer, breaking off some smaller particles – you have weathered the rock. If you then pour water or blow some air at the rock pieces causing them to move from that point to another place, then erosion has occurred. Kapish!

The processes of erosion and weathering may occur independently but most likely together but they are exclusively not the same things. Although weathering can be considered as the first step of erosion, it is not necessarily the same as erosion.

Just like in the illustration I made earlier, small particles need to be separated from the earth (i.e. weathered) before it can be carried away by the forces resulting in erosion. I would like to take a look at the ways by which the earth can be weathered.

Sometimes, it is physical

This simply occurs as a result of physical interaction of the rocks with the forces responsible. Also referred to as mechanical erosion (or weathering) the force exerted on the earth causes the surface particles to yield and thus break off.

Sometimes it is chemical

In some other ways, the chemistry of the earth material is attacked and results in the breakdown of the earth material. Most times, chemical erosion is related to water and thus resulting in the eventual erosion after breaking off.

^{it is no way spiritual!}

Forces? What are the forces?

Throughout this article, I have been mentioning the word – “forces” as being responsible for erosion. Well here they are;

Water

One of the major forces that cause erosion is water and this is for obvious reasons. Water flowing in large amounts have the power of eroding anything in their way.
From the effect of (heavy) rainfall that is not channeled properly or rivers (see the grand canyon) , streams, lakes and other water bodies doing what they know how to do best – carrying soil and rock. The effect of erosion by water is seen as widening of banks or coastal areas, creation of gullys (as in the case of the story I shared earlier) or rills. Even the small droplets of rain cause erosion because the impact of the water droplet on the ground dislodges some particles and this is referred to as splash erosion.

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Wind

As harmless as the evening breeze may feel, moving air has a part to play in erosion. As the mass of air moves, it carries with it some particles of sand with it as this sand moves and hits against rocks and earth, particles might break off and get eroded (can we call that an pneumatic sand paper?).

Wind erosion does not really occur at once, I would like to call it a slow poison because it occurs gradually and the depletion of the earth or rock may not be noticed immediately but after a long time. I like to see wind erosion as a sculptor that comes once in a day to take a chip out of the work piece. You wouldn’t notice any distinct change immediately, but in the long run, you see what results of the work.

Ice

How can ice cause erosion you might want to ask? Well, I am not referring to the ice cubes you use to chill your drinks, I am talking about a moving body of ice known as glaciers
When glaciers move, they can take with them particles of sand or rock. Well, just like a sand paper, these particles weather the ground and move it along (can we call this a cold-sand paper?).

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Gravity

It is true that what goes up must surely come down but what about what has always been up? Sometimes, under the influence of gravity, rock and earth particles can come crashing down a hilly slope in the form of landslides, mudslides or rockslides causing the movement (i.e. erosion) of the earth particles. This process is usually referred to as mass movement.

Although a lot of factors such as topography, climate, presence (or absence) of vegetation and tectonic activity influence erosion, human activities such as deforestation also contribute to the circumstances that can lead to erosion. The impact of erosion cannot be sidelined as if it is allowed to thrive it can cause very catastrophic effects (like in my story) such as loss of lives and property, destruction of infrastructure, loss of vegetation as in farmlands, loss of vital soil particles responsible for agriculture etc.

How then can we control erosion?

Just like in the case of corrosion, there are a series of practices that can be done to avert the menace of erosion. Erosion control measures can be done to alter the environment to prevent the movement of the particles. Practices such as planting of trees and other forms of vegetation that can help hold the top soil in place and also break wind, construction of structures such as contour banks, barriers or baffles, proper drainage for channeling rain water.

CONCLUSION
Erosion does not seem to look like a serious issue by merely looking at it but if you consider it seriously, it is more of like a bomb waiting to explode. Just like global warming, erosion cases should not be taken lightly as it can be disastrous if not attended to. Also, environmental practices that do not support erosion should be done.
Most of the time, we try to look at the soil as a renewable resource but sincerely, the question is, is it really renewable? Although the soil is being replenished by decaying matter, the process of erosion results in more of the soil being lost than it is being replenished.

In my country, the issue of erosion is not treated with the kind of attention required and as a result, a lot of roads and similar structures suffer. The costs of erosion prevention is not as much as it would to correct the problems it would cause if allowed to thrive.

Finally, it is imperative for us humans to be aware of the gradual but dangerous process of erosion. This way we can all be able to work together to correct the issues it presents. Just like corrosion, erosion is a menace and should be stopped.

REFERENCES
Preventing and managing erosion
Effective ways to prevent and control erosion
Erosion and transport
Erosion
Types of erosion
Erosion
Erosion concept
Impacts of corrosion
Difference between erosion and corrosion