Online FDSCI 201
Lesson 6 Guided Lab—Landslides
Part I. Where Do Landslides Occur?
“Landslides and other "ground failures" cost more lives and more money each year than all other natural disasters combined, and their incidence appears to be rising. Nevertheless, the government devotes few resources to their study — and the foolhardy continue to build and live in places likely to be consumed one day by avalanches of mud.”
--Brenda Bell
There is an average of 10 landslides every day in the United States and they cost the U.S. $5 billion annually. The events usually are not national disasters, but they are disasters for individuals and families. And, sadly, with a little knowledge many if not all of these disasters could be avoided.
On the Internet or in our text, find the National Landslide Hazards Map, published by the U.S. Geological Survey. (http://landslides.usgs.gov/hazards/nationalmap/). If the link does not work, you can find it by searching “national landslide map site:usgs.gov.”
On the National Landslide Hazards Map, red denotes areas with a high incidence of landslides (covering greater than 15% of the area). There are three major zones of high incidence – one near the West Coast, one in the Rocky Mountain region, and one in the Appalachian Mountains. Areas of high to moderate susceptibility surround these high incidence regions. You can click on the dots on the online map and the map legend to enlarge an area.
1. Use the map and the map legend to help you answer these questions.
a. Write a place of interest to you in the U.S.
b. What color zone is it in?
c. What is the meaning of that color zone from the map legend?
2. All of the regions with the highest incidence rates (red and pink) are mountainous. Is this correlation coincidental? Explain your reasoning.
3. Name two other regions of the world (not the U.S.) where you think topography would likely result in a high incidence of mass wasting. (You may want to use Google Earth to help you identify regions with high topography.)
Part II. How Do Landslides Affect People?
Learn about two recent landslides. One was in New York and the other was in Springhill Utah. Use the articles linked below to help you answer the questions.
Article Links:
Springhill Articles
Do a google search to see if you can find any more recent articles about this landslide.
New York Articles
Do a google search to see if you can find any more recent articles about this landslide.
a. What do the articles say about insurance coverage for these homes?
b. Do you think the federal, state and/or local governments have a responsibility to the homeowners in the Springhill, Utah neighborhood? Explain your reasoning. (Hint: Be elaborate with your reasoning. This is a big question and your answer should reflect an informed analysis).
Part III. Recognizing Landslides
According to Nilson and Brabb (1972), landslide deposits are commonly characterized by one or more of the following features:
1. Small, isolated ponds, lakes or other closed depressions
2. Abundant natural springs
3. Abrupt and irregular changes in slope and drainage pattern.
4. Hummocky irregular surfaces.
5. Smaller landslide deposits that are commonly younger and form within older and larger landslide deposits. (Once a landslide always a landslide.)
6. Steep arcuate scarps at the upper edge. These may be smoothed by erosion and vegetation, but are often still visible.
7. Irregular soil and vegetation patterns.
8. Disturbed vegetation.
Our text has information that will help you make decisions as a property owner. Please review them for the following questions.
1. Read “Landslide Warning Signs.” The first 9 items listed are warnings that homes are in a landslide area. The other items listed mean a landslide is happening and you need to GET OUT!
2. Now read “Areas Prone to Landslide Hazards,” and “Areas Considered Safe from Landslide Hazards.”
TAKE NOTES as you review the text – You will need them as you evaluate “3 DREAM HOMES.”
DREAM HOME 1
Your former roommate is purchasing a home. Here is an e-mail and some pictures. Read the e-mail and examine the photos. Then write a response to the e-mail that answers this question: Is DREAM HOME 1 a dream or a nightmare? List all of the reasons that support your opinion. Be thorough and specific!
Email:
TO: You
FROM: former roommate
RE: Buying a house!!
Hi
I want to share our great news. We’re buying a house! It’s on SpringHill Drive – and it’s a steal of a deal. Take a look at these pictures. The house is huge and it has the most incredible views. I can’t believe we can afford it.
We are on the edge of a hill and there is a spring at the bottom of it. It’s the perfect resource for our year’s supply of water. The doors inside the house don’t shut quite right – but you know, we can fix just about anything with a hammer. Check out the pictures. Some of the roads around the neighborhood are really falling apart; I’ll have to call the city on that.
There are lots of other homes for sale in the area. You should come take a look. It would be great to have you as neighbors. I know you took a college class that helps you think about potential problems with homes. If you see anything that I should think about, let me know.
Thanks for your help.
WOW! Notice the trees in the back. The yard drops off to the spring below. / Do you think this is a problem?Vacant lot next door. We can buy it for cheap. Should be fun to landscape around this change in topography which seems to line up with our outdoor stairs. / Street in front of our new house. I don’t know what’s with the city. They should fix this – and they will once I start talking with them!
Always wanted a mailbox! / The current owners will fix this before we close.
Is DREAM HOME 1 a dream or a nightmare? Write a response to the e-mail that explains your opinion of the pending purchase. List at least 5 reasons that support your opinion. Be thorough and specific!
Type in the box – if you need more space, extend the box so it includes all of your answer.
DREAM HOME 2
You gave your former roommate such good advice that another friend has asked for your opinion on the property she wants to purchase. Read the e-mail and look at the photos.
Email:
TO: You
FROM: friend
RE: Buying a house!!
Hey! I think I want to buy this house. I’ve always liked the desert and I love this yard! Our kids will have a blast climbing around on the random boulders when they get a little older. The house is located on Rocky Road Drive – can you believe that? It’s my favorite type of ice cream! That has got to be an omen.
Desert home I want to buy. Look at that beautiful blue sky.
We plan to make an offer tomorrow. Let me know what you think. Thnx.
a) You decide to do a little research on the Internet before you respond. You come across this article on the Utah Geological website about the “Provo rock fall 2009”.
b) Respond to your friend using information from the above article.
Answer the question: Is DREAM HOME 2 a dream or a nightmare? Write a response to the e-mail that explains your opinion of the pending purchase. List all of the reasons that support your opinion.
Be thorough and specific! Type your response in the yellow box below. You can add a new page and expand the box if you need to write more.
DREAM HOME 3
This time you get an e-mail from a person that you met at a grocery store.
Email:
TO: You
FROM: JER
RE: INVESTMENT OPPORTUNITY!!
Hi. Remember me? I met you at the grocery store a while ago. Remember how we were talking while we waited in line about investments and places to build a house. Well, have I got a deal for you. I found the perfect place to build a home! My parents’ friends are working on a new housing development – it is in a great area with beautiful views. I’m helping them sell lots so I’m letting all of my friends know about it! You really should check this out!!!!
This beautiful area is close to the mountain front, is at the mouth of a small canyon (see picture), and is not too far from an LDS temple. There isn’t any water in the canyon most of the time – just a dry stream bed – perfect for hiking. There was a fire up the canyon last summer which is great – it cleared out all of the dead wood so you won’t have to worry about a wildfire destroying your new house.
I’m pretty sure that I can get you a sweet deal on a lot. Give me a call and I’ll give you a tour of Alluvial Heights – catchy name don’t you think – I thought of it because it is built on an alluvial fan! Hurry so you can get a lot close to the mouth of the canyon – they have the best views and most open space.
Check it out on Google Earth, at: Latitude 40.539645,
Longitude - 111.807099.
CALL SOON – JER
Before you respond to JER, you decide to do some research on the Internet. At a minimum, do the following:
a) Read the following sections at http://pubs.usgs.gov/fs/fs-176-97/fs-176-97.html:
- “Dangerous, Fast-Moving Landslides”
- The pictures and descriptions in “Hazardous Areas”
Or search “debris-flow hazards in the united states site:pubs.usgs.gov” to find this article.
b) Go to the following website, scroll down and read “Tips and Clues that May Save Your Life” from http://www.consrv.ca.gov/cgs/information/publications/cgs_notes/note_33/Pages/Index.aspx
Or search “note 33 site:consrv.ca.gov/cgs” to find this article.
c) Determine why the USGS monitors burn areas. http://landslides.usgs.gov/research/wildfire/ Or search “post-wildfire landslide hazards site:landslides.usgs.gov” to find this article.
d) Watch the following 20 second video. It shows a debris flow in California, there is no sound. http://www.usgs.gov/homepage/science_features_images/debris_flow_ca.wmv Or search “debris_flow_ca.wmv site:usgs.gov” to see this video.
Is DREAM HOME 3 a dream or a nightmare? Write a response to the e-mail that explains your opinion. Be thorough! In your response, tell JER the single most important thing he should tell people who build homes in Alluvial Heights. Tell him at least three other things that he should tell the people. And explain whether or not the wildfire was a good thing.
Type your response in the yellow box below. You can expand the box if you need to write more.