Download Human Impact on Erosion Article 2003

Human Impact on Erosion
Erosion is the process that carries sediment and rock to other places. There are 4
natural causes of erosion…. Wind, moving water, gravity (causes landslides), waves, and
glaciers (rivers of ice). Look at the pictures of these below.
There are 4 ways that humans contribute to the erosion process. 1) Logging 2) Farming
3) Mining 4) Construction. Read on to find out why these things are good, how they cause
erosion (bad), and what we are trying to do about it.
What is so important about soil that we should bother preserving it?
 Soil provides minerals & nutrients for plants.
 If plants can’t get nutrients from soil, neither can the animals or humans get
the nutrients they need
 Stores water to provide moisture for plants and prevent floods or run-off
b/c it is able to absorb into the soil
#1 Logging
What’s so great about logging?
Anytime you are using wood, you are using a tree that
was cut down by logging. The pencil you are writing with,
the furniture you have at home, and your house are all
made of wood, that came from trees. Oh, the paper you
are reading and writing on was also made from wood
that come from trees. So, in a sense, we all cause
logging to happen because we use the trees for our
needs every day.
Why’s logging so bad?
You’ve probably heard about the logging in the rainforest. You know that logging (cutting
down large amounts of trees at one time), causes the animals to lose their homes, kills
many species of plants and animals, and less trees means less oxygen. We know that the
roots of trees hold the soil in place, so without the trees, the soil is washed away. The
problem is, soil cannot be replaced. Logging is not just happening in other places, it
happens here too. Erosion happens when there is nothing left to hold the soil in place.
Unfortunately, if nothing is done, we use that soil forever.
What are some solutions?
Some suggest that we should plant a tree everytime we cut down a tree. It makes sense,
right? However, there are a lot of people who are doing the logging that don’t care much
about the environment. Many times, logging is done illegally, and governments have
created laws to protect the land from further logging.
#2 Farming
Why do we farm? What are the benefits?
Farming provides us with food. Almost all the fruits, vegetables, and grains you eat
come from farms. Someone had to grow the lettuce that makes up your salad, the grains
that make up your bread and pasta, and the fruits on your lunch tray. Without farming,
we would have to plant our own food. Farming benefits us all by providing food, which
provides nutrients we need to grow, live, and be healthy.
How does farming cause erosion?
When we over- farm, or farm too much on a piece of land, the soil on that
land can lose nutrients and become infertile, meaning, it cannot support plant life.
This can happen when we use a piece of land and farm on it over and over and over
again. If we do this, the soil is not healthy. If it is not healthy and has no
nutrients, it can no longer support plant life, the plants die, and there is nothing
left to hold the soil in place. The roots of plants hold the soil in place and prevent
it from eroding away. Without plants and their roots, we say good-bye to soil.
When there are no plants and no nutrients, the land becomes a desert. When this
happens, we call the processes desertification also known as land degradation.
This was exactly what happened when we had the Dust Bowl in the midwestern United States. The drought did not allow the plants to grow. The plants
died, and they were no longer there to hold soil in place. This is why it was very
easy for the wind to pick up the soil, causing erosion. When the wind picked up,
the air was filled with clouds of dirt and dust.
How do we try to conserve (save) the soil?
1. Contour plowing: On gradual slope (such as a short
hill), rows of crops run horizontal to each other and
act as barriers for rain. If the rows of crops ran
vertically, up and down the hill, they would become
channels for the water to wash the soil away
downhill, thus causing erosion.
2. Terracing: This is typically used when there are a lot of mountains. If the
farmers planted their crops on the steep
slope, it would make it easy for the crops
and soil to erode away every time it rained.
Instead, the farmers cut into the mountain
what looks like a staircase. Each step is at
least a couple feet wide and is flat (just
like the steps you use). The flat part is
where the plants are planted. This way, the
water will not wash the plants and soil
down the hill.
3. No-till farming: When farmers harvest their crops, the soil would be left
without anything to hold in in place, unless the farmers put something into or
on top of the soil. No-till farming is when farmers leave old stalks from corn
stalks or other plants behind. These stalks cover the soil, and keeps rain
from taking so much soil away.
4. Cover crop: There are some crops that don’t deplete (take out) nutrients
from the soil. Instead, they replenish, and add the nutrients back into the
soil, restoring it so it can be used for farming again. Crops that restore the
soil are called cover crops. Examples of cover crops are peanuts and soy
beans.
An example of when cover crops has been used was during
the 1900s, when soil was depleted from only planting one
crop: cotton. George Washington Carver, a scientist,
encouraged them to plant peanuts and soybeans to
replenish nutrients. These prevented erosion by providing
cover from wind and rain. This is why they are called cover
crops. These are planted in between harvests.
5. Crop rotation: different crops use certain nutrients from the soil. Planting
the same crop all the time depletes certain nutrients, so farmers plant
another crop that will use different nutrients or use less nutrients. This
way, not all the nutrients are being depleted at once.
6. Matting
“Soil erosion prevention products are available in many styles. One of the
most common products which are most commonly used on residential
properties, vegetation crops and vacant land is matting. Matting is
available in wood fibres which make it environmentally friendly and
biodegradable. The matting will be placed on the soils surface and prevent
erosion from occurring. The matting will allow plants, crops and trees to
grow through it and the soil will be healthy and stabilized. Matting can be
cut to size to suit your property.”
7. Mulch/Fertilizer
“Another soil erosion prevention method which is beneficial
to the soil and plants which live in it, is applying a layer of
mulch and fertilizer over the soil. The mulch and fertilizer
layer will assist the soil to soak in water slowly and it will
also lessen the impact of rainfall as it penetrates through
to the soil. The mulch and fertilizer layer will also stabilize
the affect soil by regaining its PH levels to be healthy and neutralized.
Any type of mulch or fertilizer can be used to prevent soil erosion.”
http://www.landscapeplanet.com/maintenance-1-soil-erosion-prevention.htm
#3 Mining
Why do we mine? What’s so good about it?
During our minerals unit, you learned about mining, which is what we do to
get minerals out of the Earth. We use minerals for all kinds of things. You might
first think of beautiful gemstones, like diamonds and rubies, but these are not the
only minerals. We learned how there are many different types of opal that are
mainly mined in Australia. We also learned about minerals like calcite, fluorite,
apatite, and quartz. Minerals are in our food and water, the chair you are sitting
in, the pencil you are writing with, and the building you are sheltered by. Anything
that is metal is made from minerals that were mined from the Earth. Coal and oil
that create electricity, heat, air conditioning, and keep are cars moving are all
extracted from the Earth from mining. If we didn’t grow it, most likely it was
mined. We are highly dependent on mining for most of the things we use on a daily
basis.
If mining is so good, how can it be bad?...How Mining Causes Erosion
When we are using subsurface mining to get into the Earth, we are breaking
up the surface where the soil and rocks are in order to get below the surface
where the minerals are. We destroy homes of plants and animals. When we cut
down the trees and get rid of the plants, we remove what was holding the soil in
place. Therefore, when it rains or the wind picks up, the soil and dirt is eroded
away.
Another way mining can cause erosion is from the dynamite blasts that are
used to break the rock apart. This can create steep slopes, and the shake from
the blast can cause a landslide or rockslide, which quickly erodes soil and rock
away. When we mine, the heavy mining equipment can also cause damage to the soil
or carry it away.
What are we doing to solve the problem of mining?
We can all help prevent the problem of erosion from mining. When we reduce
the amount of materials that we use that are made of minerals, we are reducing
the amount of times the miners have to destroy areas of land to mine. When we
reuse and recycle what we have that is made of minerals, we are making the most
of what we have, and therefore won’t have to dig up the ground as much for
mining. Less mining=less soil erosion. We also learned about mine reformation,
when they do their best to change the land back to its original state. This can
happen by planting trees and grass to hold the soil in place.
Construction
Why do we have construction?
Most of the land we live on today was covered in trees and grasses. Then,
humans came and we started to build homes and towns. When we did this, we
removed plants, trees, and grasses that held the soil in place. Today, we are still
building neighborhoods, apartment buildings, and homes. We are buildings malls,
stores, and restaurants. We build schools and hospitals.
What’s the problem with construction?
Whenever something is built, we remove the plants that held soil in place. While
we are building, the ground is covered in dirt and exposed to agents of erosion. If
it rains, that soil and dirt is quickly washed away. The soil is then carried away to
the rivers and to the oceans.
What are we doing to solve the problem?
After neighborhoods and shopping centers are built, we regrow grass and trees,
bushes, and shrubs, flowers and gardens to hold the soil in place.
Construction crews have specific laws that they have to follow when constructing
new buildings. These laws help prevent soil erosion. For example, some develop only
certain portions of the land at a time. Instead of clearing a whole area at once, clear the
land in sections so that you immediately build on what you are clearing. When you are
done with that portion, clear more land to continue building. If you build on it right away,
less erosion is going to happen.
If you have to clear land away, but it is not going to be used for a while, cover it
with seed so grass can grow to hold the soil in place. You can also cover it with mulch.
This way, something is holding the soil and dirt in place.
As soon as we are done with construction to an area, we need to put down mulch,
seed for grass, or plants to grow and hold the soil in place.