PURPOSE
The purpose of this experiment was to see what materials work the best
in a sandbag for preventing a flood. Fine and coarse gravel, plant soil,
and mulch are not usually put in sandbags to stop floods. Most people do
not have a lot of sand that they can put in sandbags. That's why
I'm doing this experiment, to see if fine and coarse gravel, soil, or mulch
can have the same effect as sand.
I became interested in this idea when I heard about people losing their
homes and lives to floods. The spring of 1996 had many terrible floods
in the Yakima Valley.
The information gained from this experiment will help people prepare
for floods and save their lives.
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HYPOTHESIS
My hypothesis is that materials with more density will be more effective
at blocking floodwaters.
I base my hypothesis on Internet website that tells about flood protection
with sandbags.
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EXPERIMENT DESIGN
The constants in this study are:
size of sandbag
shape of sandbag
mass
the water flow
structure of sandbags
time the water runs through the flood table
The manipulated variables are the different materials in the sandbags
(sand, gravel, mulch, and soil).
The responding variable is what amount of water flows past the sandbags.
To measure the responding variable I will need a container that measures
the amount of water that passes past the sandbags.
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MATERIALS
| QUANTITY |
ITEM DESCRIPTION |
| .9144 |
square meters burlap |
| 1 kg. |
sand |
| 1 kg. |
plant soil |
| 1 kg. |
fine gravel |
| 1 kg. |
course gravel |
| 1 |
flood table |
| 1 |
marking pen |
| 3 |
2.84 liter bottles |
| 1 |
bucket |
| 1 |
sewing machine |
| 1 |
stop-watch |
| 1 |
can paint bucket |
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PROCEDURES
1 Make the sandbags by using 1 square yard of burlap.
2 Cut each sandbag into 6x6 inch squares.
3 Fold them in half and sew them into bags.
4 Put a half-cup of the first material in the bags.
5 To make the flood table, use 4x1x1 foot pieces of wood. Screw them
together.
6 Put a 1-inch piece of wood under the top of the table so it gets
a slight incline.
7 Place a bucket at the end of the flood table measure the amount of
water that goes past.
8 Place the sandbags on the flood table 2 and a half feet from the
top. With a pen, mark where that is so you can get the same every time.
9 Stack the sandbags so they are as tight as they can get.
10 While stacking the sandbags, make sure there is 3 on top and three
on bottom.
11 Run a flood by steadily dumping 2.84 liters of water at the start
of the flood table.
12 Start a stop-watch when the first drop hits the flood box.
13 After 25 seconds, record how many millimeters of water goes past
the sandbags.
14 Run the test three more times with the same material.
15 Use the next material.
16 Repeat steps 8 through 15 using the following materials: sand, fine
gravel, course gravel, and soil.
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RESULTS
The original purpose of this experiment was to see if different materials
in sandbags besides sand would work if put in front of a flood.
The results of the experiment were sand let the least amount of water
past through the sandbags, an average of 848 milliliters of water in 25
seconds. Plant soil, the next best material, let 1,360 milliliters of water
past through them. Then came fine gravel. It let through 1,439 milliliters.
The material that let through the least amount of water was coarse gravel.
It only held back 1,912 milliliters.
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CONCLUSION
My hypothesis was that materials with more density will be more effective
at blocking floodwaters.
The results of the experiment were sand let the least amount of water
past through the sandbags, an average of 848 milliliters of water in 25
seconds. Plant soil, the next best material, let 1,360 milliliters of water
past through them. Then came fine gravel. It let through 1,439 milliliters.
The material that let through the least amount of water was coarse gravel.
It only held back 1,912 milliliters.
Because of the results of this experiment, I wonder if something solid
like concrete, steel or metal would work as well or better. Also, I think
that the more compacted the material is, the better it works.
If I were to conduct this project again, I would test more types of
materials; like clay, sawdust, wood chips, etc. I would run a more accurate
flood, make bigger sandbags, make a more waterproof flood table, run the
test longer, make sure that all sandbags are the exact same size, and many
more.
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RESEARCH REPORT
INTRODUCTION-
Many thousands of people and homes have been killed or injured in floods.
Sandbags help to prevent floods from damaging homes. They also help save
peoples lives.
Sandbags/Materials
How to build a sandbag dike-
A properly built sandbag dike can reduce or prevent flood damage.
To make a dike 1-foot high, you need to use 800 sandbags. To make a dike
2-foot high, you need 2,000 bags; and for a 3-foot high you need 3,400
bags. When filling them make sure and fill them only half way full.
Site Selection- When deciding to make a sandbag dike you should place
it in a place where it has all the natural advantages. You should try to
keep it as low and short as possible. Also avoid anything that would weaken
the dike. Leave about 8 feet in between the dike a building.
Stacking the Sandbags- when you are stacking your sandbags, you
should remember to have the base of your dike 3 times as wide as it is
high. You should over-lap the sandbags so that the full part of the sandbag
is lying on the half-empty part. The second layer of the dike should look
like the first layer.
Sealing the Dike- To seal a dike you need a sheet of plastic to improve
water tightness. Put sandbags on top and bottom of the dike to weight the
plastic down. Try not to puncture it.
MATERIALS-
Sand- Sand is a mass of minerals. It is made of very fine grains. Sand
is made of Mica, feldspar, magnetite, and other minerals. It is very important
to soil. Sand is formed through the process of erosion. When sand is first
formed it is very sharp. After a while it becomes smaller and more rounded
by wind and water. Sand is used to make many things.
Gravel- Gravel is a very loose material made of small rock and mineral
fragments. Gravel is larger then sand particles. Gravel is deposited along
lakes, rivers and oceans. Beach gravel is very round and smooth because
it gets worn down. When gravel is used in industry, it is mixed with a
dark tar-like substance, then is used to build roads, railroads, airfields
landing strips, and much more.
Soil- Soil is made of sand, silt, clay, etc. Sand is an important resource;
all life on earth depends on soil. Soil is developed through centuries
of materials collecting together; and through erosion.
Mulch- Mulch can be many different things like grass, straw, manure,
hay, clover, chaff, alfalfa, corncobs, leaves, sawdust, wood chips, and
more. Mulch helps decay and enrich the soil. It helps keep air in and water
from evaporating out. Mulch also keeps weeds from growing. When placing
mulch on the ground place it 2 to 3 inches thick.
Floods-
A flood is a body of water that comes over dry land and carries topsoil
away and leaves the land bare. Floods are usually harmful to people and
homes. Floods are sometimes helpful by making the land very fertile.
Seacoast floods- Seacoast floods usually kill hundreds of thousands
of people, and destroy millions of homes. Seacoast floods usually result
from hurricanes and big storms. A giant sea wave caused by an earthquake
is called a Tsunami.
River floods- Most rivers overflow once every two years. Too much rain
at one time sometimes floods rivers. Sudden melting of snow and ice does
too. When this happens the riverbed has ten times as much water as the
river can hold. Heavy rain or thunder storms usually cause flash floods.
They mostly occur in the mountains. Flashfloods come fast and unexpectedly.
People dont have time to get ready and react to them. Some rivers, like
the Hung He in China, have killed nearly a million people.
Tropical Storms floods- Tropical Storm floods usually form over warm
water of the tropics and are loaded with moisture. When storms make their
way to land, they bring inches of rain. This causes streams and rivers
to overflow.
SUMMARY
Floods can be helpful to the environment by making the land very
fertile. They can also be dangerous to houses and deadly to people. Sandbags
give people a chance to prepare themselves for a flood that could kill
them. If you make a properly built sandbag barrier, you can help in the
prevention of a floods danger. Materials like sand, gravel, and soil may
help in flood protection. Seacoast, river, and tropical storm floods are
just some kinds of floods that can be deadly and disastrous.
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BIBLIOGRAPHY
"Floods" Comptons Interactive Encyclopedia 2000
"Gravel" Encarta 98
"Mulch" Encarta 98
Rango, Albert "flood" The World Book Encyclopedia, 95 vol., F-9 pg.
237-238
Sandbagging for Flood Protection,
http://ext.nodak.edu/extpubs/ageng/safety/ae626w.htm
"Sand" Encarta 98
"Sandbags" Groliers encyclopedia 98
"Soil" Encarta 98
Waters, John, Flood! Crestwood house, Macmillan Publishing Company,
pg. 10-
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