In this lab, the student tested how the size of beads affected porosity, water retention, and permeability. Small beads had the highest porosity and retained the most water, while large beads were the most permeable. For the sediments activity, using a sedimentator showed which materials sank and which floated in simulated rivers and lakes. The soil organization lab simulated soil profiles for different habitats, finding prairies were most permeable and rainforests least, correlating with rainfall amounts.

1. Rohan Rao
Block 6
Investigating The Movement Of Water In Earth
In this lab, we were testing to see what the effect of changing the size of beads
does to the porosity, the amount of water retained, and the permeability of water. We had
three test groups: small beads, large beads, and unsorted mixture. For each group, we
poured water in and measured how much water was needed to get the water level to
reach the top of the beads, to test its porosity. To measure how much water was retained,
we poured in water, and took the water out, and measured the difference to check how
much water was retained. We also measured the time it took for 100 mL of water to
completely go through each set of beads, in order to see the permeability of the water.
After testing for porosity, we were able to determine that our small beads were the
most porous with 62 mL of water, then the large beads with 60 mL of water, and last was
the unsorted mixture with 40 mL of water. These results show that the tube with the small
beads is the most porous, which means it has the highest percentage of open space
between particles. Therefore, the unsorted mixture of beads has the least porosity,
because there is the least percentage of open space between particles. In addition to being
the most porous, the small bead sample retained the most water. It retained 18 mL,
whereas the unsorted mixture retained only 10 mL, and the large beads only retained 2
mL. This means that after pouring in 100 mL of water into each sample, we were able to
drain the least amount of water from the small beads, because a good portion of the water
was stored in the beads. The large beads were the most permeable, because they had the
smallest time taken for the water to go through with an average of 4.97 seconds, then the
unsorted mixture with 6.34 seconds, and lastly the small beads with 8.7 seconds.
Step Small Beads Large Beads Unsorted Mixture

2. Porosity 62 mL 60 mL 40 mL
Water Retained 18 mL 10 mL 2 mL
Permeability 8.7 seconds 4.97 seconds 6.34 seconds
Sediments Activity
For the sediments activity, my group looked at a Sedimentator to observe and
classify various sediments. We adjusted the Sedimentator in many different ways, to see
which sediments were formed. It also helped us understand the different layers among the
sediments. The Sedimentator was very beneficial, because it accurately portrayed how
each of the sediments interacted and which ones rose to the top, and which sunk to the
bottom. We tried to create a lake bottom by shaking the Sedimentator, and laying it on its
side. We also set up a simulated river with flowing water by gradually tilting the
Sedimentator up and down.
After repeating the simulation a couple times, we noticed that the sediments
would sink to the bottom of the water, and sediments are also deposited in creeks and
streams. We saw that the sand and rocks sunk to the bottom, and the clay stayed near the
middle of the Sedimentator. As for the flow of water in rivers, the silt seemed to float
along the stream, but the sand, gravel, and boulders sunk all the way to the bottom. If the
larger sediments move around, such as the boulders, then they could begin to becomes
smaller, due to weathering. The reason for this is that they would be moving back and
forth along the bottom and the sediment as whole would begin to diminish. This lab
allowed us to understand that sediment is created by weathering or decomposition.

3. Soil Organization
In the soil organization lab, we simulated the soil profiles of the desert habitat, the
prairie habitat, and the temperate rainforest habitat. We used cheesecloth as a barrier, in
order to test the permeability of these three habitats. Our group meticulously created the
the O, A, B, and C layers of soil in each of these habitats. Then, we measure the absolute
threshold of the habitats to see at what point would the water begin to be able to go
through all four of the layers.We used colored water to simulate organic nutrients that
may be on the surface.
After testing, we were able to determine that the prairie was the most permeable
of the three. This means that water could pass through the prairie habitat the easiest, and
in this case that means that it took the least amount of drops for the water to pass through
the four layers of soil. In addition to determining that the prairie was the most permeable
habitat, we were also able to find that the soil of the desert was the second-most
permeable, and the soil of the temperate rainforest was the least permeable. In addition,
we were also able to see a negative correlation between the amount of rainfall, and the
permeability of the soil in the temperate rainforest; the temperate rainforest receives the
most rainfall, but is the least permeable of the three tested habitats.