Urban Infrastructure
and Erosion
School/program name
Date
Background Information
(for facilitator)
•
Erosion is the process by which rock and soil are removed from a particular location by agents such as flowing
water, wind, glaciers, and gravity. It is distinct from other geologic processes such as mechanical or chemical
weathering, transportation, and deposition. Weathering is the breakdown of rock, not the removal of rock.
Transportation is the movement of eroded rock material by various means, such as wind or water, from one place
to another. Deposition occurs when the transported materials are finally laid to rest, usually at a lower elevation,
where they can become part of the soil or eventually once again become rock. Weathering, erosion,
transportation, and deposition all act together as a part of the rock cycle. These processes help to create, shape,
and ultimately destroy many of the landforms on Earth, including canyons, deltas, beaches, caves, glacial craters,
plains, and sea cliffs.
•
It is important to distinguish between the processes of erosion, weathering, transportation, and deposition.
Erosion is the removal of rock or soil from where it originally formed, or from where it was later deposited, and
weathering is the physical or chemical breakdown of rock. In the case of mechanical weathering, rock breaks down
due to forces such as abrasion, ice wedging, or thermal expansion. Chemical weathering occurs when rocks break
down by reacting chemically with substances such as water or chemicals from organisms such as lichen. Erosion is
distinct from transportation in that, while erosion is the removal of material, transportation is the movement of
eroded material to another location. Natural agents such as water or wind transport the eroded material to other
places. After rock or soil has been transported, it is deposited in a new location that is at a lower elevation; this
deposition is caused by the force of gravity.
•
The mode of erosion and transportation depends on the slope of the land and the materials of which the land
consists. Steeper slopes and more loosely cemented rock materials can produce rock falls and landslides, whereas
gentler slopes made of more consolidated materials are more likely to change gradually as materials move down
slope in a process known as creep. Landforms that are produced by the combination of erosion, gravity, and
transportation by water include landslides, mudslides, glacial lakes, sandy beaches, deltas, and canyons. Note that
the terms landslide and mudslide can be used to refer to the transportation event as well as the resulting
landform.
Agenda
Opening (30 minutes)
Setting the Stage (15 minutes)
Activity: Go with the Flow (45 minutes)
Break (15 minutes)
Setting the Stage (5 minutes)
Activity: The Trail That Would Fall (60 minutes)
Cyber Investigations (15 minutes)
Virtual Lab: Erosion – Here Today, Gone Tomorrow
Lunch (30 minutes)
Recess: Water Balloon Race (30 minutes)
STEM-tastic Careers (30 minutes)
Dream School Engineering Challenge: Phase Five (45 minutes)
Mind Snacks (20 minutes)
Dream School Engineering Challenge: Phase Six (40 minutes)
STEM Camp Notebook Reflection (10 minutes)
Wrap Up (5 minutes)
Dive Into Digital Project (60 minutes)
Learning Objectives
To explain erosion
To comprehend how erosion can damage
urban areas
To discover how urban infrastructure can
affect erosion
Today’s Vocabulary
Erosion
Weathering
Physical
Chemical
Sediment
Setting the Stage
What is Erosion?
Activity:
Go With The Flow
Setting the Stage
How does urban development
affect erosion?
Video: Urban Development: A Process of
Depleting and Replenishing the Land
Activity:
The Trail That
Would Fail
Cyber
Investigations
Virtual
Lab
STEMtastic
Careers
How do the scientists at The Nature
Conservancy help protect urban
infrastructure from the forces of
erosion?
In addition to protecting urban
infrastructure from erosion, what other
benefits come from the work of these
scientists?
What inspired these scientists to do the
kind of work that they do?
Dream School Engineering
Challenge: Phase Five
Mind
Snack
Dream School Engineering
Challenge: Phase Six
Notebook Reflection
Describe the measure(s) your team is taking
to mitigate erosion around your Dream
School’s property.
Wrap Up
Think about this…
So far, we have discussed earthquakes and
erosion. What other geologic factors do you
think must be accounted for when designing
urban infrastructure and your Dream School?