Monday, November 16, 2009

Remote Sensing and GIS Lab



This week’s lab is posted directly on the blog. Follow the instructions in the lab. Along the way you’ll see links that define words and/or take you to sites that you need to complete the lab. Click on the links and explore. If you don’t know a word and it isn’t defined below, Google it. The world is a big place, and this lab is designed to give you the tools to look at it as a whole. Enjoy!



Conservation Biology: Using GIS and Remote Sensing to Understand Deforestation of Biodiversity Hotspots



Goals for this lab:


1. Learn to use Google Earth, a sophisticated yet easy tool for remote sensing and communicating results.


2. Identify biodiversity hotspots and analyze threats to tropical forests.


3. Make a short presentation on the threats to the biodiversity hotspot of your choice.


4. Communicate your results to the wider world through your TA.


5. Get a broader picture of the world we live in, the stage for the entire drama of life.


Introduction
It seems like every day in the news you hear something about large-scale changes in the Earth system.  Global temperature or precipitation is changing, CO2 emissions are increasing in different parts of the world (display US data by state in Google Earth), sea ice in the Arctic Ocean is at a minimum, glaciers and ice sheets are receding, forest fires and deforestation are occuring throughout wide areas of the tropics, or that ocean temperatures and chlorophyll content are changing in parts of the Pacific.  One question that should run though your mind is, "how do we even know that these things that happen on such vast spatial scales are happening, and how do we measure them?"
Ecologists and conservation biologists are interested in ecological and evolutionary processes that occur on large spatial and temporal scales as well. Two of the tools we use to look at these are called Geographical Information Systems (GIS) and Remote Sensing. We’re the first generation that has access to tools that lets us monitor the entire globe–from ocean temperatures to cloud cover to terrestrial and oceanic primary productivity to forest cover change–and use these tools to answer scientific questions. Today we’re going to use these tools to look at forest cover and patterns and causes of land–use change in the areas that have the highest biological diversity on the planet, place that scientists have termed Biodiversity Hotspots or just plain Hotspots. You’ll use these links for a large part of the lab today.
Democratization of Remote Sensing and GIS: Google Earth
GIS and RS used to be the realm of a techno-shaman like Sassan Saatchi at the Jet Propulsion Laboratory in Pasadena. (His work on African and Neotropical forests is amazing.) Not anymore. The free version of Google Earth (GE) available online has democratized remote sensing and GIS so that even first-timers can ask global-scale questions about remotely sensed data, then archive the data in ways that communicate their observations and findings to others. For example, the global spread of swine flu (H1N1) is being monitored using Google Earth, and GE is also used to aid in natural disasters, such as the the earthquake relief effort in Pakistan in 2005. Many of the data we'll use for the rest of the course are available in Google Earth too (some land and ocean data here)--it is an excellent resource for Earth Science.  Download Google Earth and set it up on your computer. There is a great blog that you can use to see some of the uses of Google Earth, and the blog also has tips about setting up Google Earth for maximum utility.

Exercise 1: Getting Started with Google Earth
In this section you will

  • Learn how to use the basic controls of Google Earth
  • Dowload a file that guides you to places on the earth
  • Learn how to create and save files to your computer
  • Learn about the basic kinds of satellite platforms and their capabilities
What you see at first is a picture of the entire earth. Try grabbing the globe with the cursor and moving it around. Look at the product tour for Google Earth to familiarize yourself with the controls. Use the “zoom” button to get closer to the globe. On the control bar you can see the equivalent “altitude” that you are looking at the earth from. Check this frequently so you can keep an idea of the scale of the features you are looking at. Turn the 3-d view by going to "tools --> options" and then checking the “terrain” box.  Try tilting the view and flying across the landscape--definitely check out the mountains. You can turn off the latitude and longitude grids by hitting Ctrl+L, or going to the view menu. Make sure you know what latitude and longitude tell you!
Two things you’ll need to do today are not covered in the tour: 1) save what you are looking at, and 2) make and annotate placemarks. You make and save pictures of whatever you’re looking at on the screen by choosing File and then Save Image (or just hit Ctrl+S). You can put these pictures into Powerpoint and use them to illustrate points about deforestation and land cover. To put a placemark anywhere on the globe, first find the location where you want to place it. Then in the menu, go to Add and choose Placemark (or just hit Ctrl+N). A dialog box will pop up where you can type in information about what you are seeing, measurements you have taken, observations, notes, and even links to web sites. On the left side of the dialog box will be a place where you can click “New Folder”. Do that and label it “Mybio113” or something like that. When you click OK, the placemark is put down on the location you chose, and the information linked to it is put into the new folder you just made. If you need to move a placemark, just double click on it, then drag it to a new position. Single placemarks, or your entire placemark folder can be saved by putting the cursor over the folder and right clicking. You'll be making a file that ends with .kmz, and you can share that with other people. Choose Save As to put a copy in another folder on your computer, or Email to email the placemark folder to your TA. To see an example of what you can do, check out Dr. Silman's Fire Scouting trip in the high Andes.

We’ve made a file for you that has several placemarks in it. Download the file and double click it. This places a folder named “Bio113” under your “temporary places” dialog in the places box. Open the folder and click on Bio 113 Lab.
Next, find your house, make a placemark on it, and save it to your placemark folder. What is the latitude and longitude of your house? What is it for your neighbor’s house? (Note, wherever you put the cursor, Google Earth gives you latitude and longitude.) You'll see that there are two different resolutions in the images. LANDSAT images have a resolution of 30m. High resolution images are usually from the Ikonos or Quickbird satellites, which have resolutions of 1m and 60 cm! These let you see individual tree crowns, lines on roads, and even people!  These satellites are just a couple of the myriad sensors that we have to look at the earth, each of which is designed to look at different aspects of the earth system.

Go see Paris, or the Pyramids at GizaEgypt. Fly into the site of the new Wake Forest Marine program at Lighthouse Reef atoll, Belize. (Use the search dialog box.) Annotate your placemarks, and make a web link to something interesting and put that in the annotations. Open any folder on your computer and type "\\Acfiles\www-home" in the address bar. This is your Deacon On-Line Directory. When you save a file here, the file will have the web address "http://www.wfu.edu/~yourusername/filename.extension". Link the file to your blog and publish your post. Now it is online!


In this section you will

  • Learn about the basic kinds of deforestation as they appear from space
  • Dowload and examine imagery that shows a time-series of deforestation in the Amazon Basin
  • Calculate deforestation rates in tropical rain forest
Deforestation is a significant threat to biodiversity and adds more CO2 to the atmosphere each year than all transportation on earth combined.  How do we know this?  Remote sensing is a powerful tool for looking at the land cover change and turning that into data we can use to answer important questions on large scale patterns and processes in the earth system. Check out NASA's excellent site and familiarize yourself with the different kinds of patterns and how we detect them.  This KMZ file on global deforestation is an overview of deforestation rates for each country on earth. The remote sensing tutorial has a page showing the various patterns and extent of deforestation too (look halfway down page). Here is a great view of deforestation in Bolivia. Now look at the area around Manaus, Brazil. (Note the different resultions of images in your view.) Download the LANDSAT time series overlay and wait for it to load. Go to the Google Earth Temporary Places folder and un-check the 1987 folder to see the change in deforestation between 1987 and 2001. You can compare the deforestation between 2001 and today by turning the 2001 image off, and also by turning the 2001 image off and looking at the current (2008) image of Manaus.  The resultion of the 2008 image is higher, and it is from a different sensor, but you can still see the patterns of deforestation.  Now, was deforestation greater in the period 1987-2001, or 2001-2008?  What might affect deforestation rates?
Your TA will help each group in the lab select one of the sites placemarked in the Bio113 folder. Go to the placemark that you have been assigned, and familiarize yourself with the geography of your area. Look at the site. What are the defining features of your site? What is unique about it? How can you recognize different kinds of farm fields, plantations, and settled areas?

Next, determine what type or pattern of deforestation is shown. What are the general causes of deforestation there? What are the patterns of deforestation? Is it large scale, or small scale? Is it centered near large settled areas, or evenly distributed? Look for the causes of deforestation at your site on the web. What is the deforestation rate (you can find this information on the appended web sites)?
Next, we'll use Google Earth (GE) to measure the amount of deforestation in your area.  First, using the path tool in GE, draw a path around the deforested areas in your image.  Second, right click on the new path and save it on your desktop.  Below the file name click the extension "kml" instead of the default "kmz." Next download the program GE Path.  Save the latest version to your c:\temp directory, unzip the file, and then run the setup.  GE Path takes the path files that you save in Google Earth and will tell you all sorts of information about them.  IN this case you will be using the information about the area of the deforested region.  Once you have downloaded and installed the program, open it. Go to the file menu and choose your kml file.   In the bottom section called Area/Perimeter, check the "area" box, and just below that choose the method, "large area."  Finally, to get the measurement, choose the "Run" menu at the top.  The area in km2 should appear in the box next to "area."  Does your measurement come close to the published value for your site?
After about 10 minutes, you should be able to recognize the major features shown by your site. When everyone has finished working, each goup in the class will have 5 minutes to demonstrate the features of their assigned site to the class, using a computer connected to a video projector. The easiest thing to do is to put the information on your blog and let your classmates see it while you tell them about it.
Exercise 3: Deforestation Patterns & Conservation Issues in Biodiversity Hotspots
In this section you will

  • Study one of Earth's biodiversity hotspots in more depth
  • Share information with you classmates via the internet
Now, go to the Biodiversity Hotspot home page. Your TA will help you select one Biodiversity Hotspot Region to work on.  Here is a Google Earth KMZ file that has all of Earth's hotspots plus information on them. Your task for the rest of the lab is to put together a brief visual summary report of the site, using annotated placemarks in Google Earth. Your report should be built around a placemark or group of placemarks in the same Google Earth folder showing the site’s location. (Hint, if you right click on the folder that contains the placemarks it makes one Google Earth file with all the placemarks in it.) Links to that placemark on your blog should show or include:
  • The topography of the site.
  • Remote Sensing images that highlight the site’s problems or threats.
  • Images of the biodiversity and/or major threatened species.
  • Rate and type of destruction.
  • Current efforts to protect the site.
In the last hour of lab, each group will present a short oral report on their site for the class using Google Earth.



Useful Resources
General information on the status of rain forest conservation with country summaries:http://rainforests.mongabay.com/
Deforestation rates: http://www.mongabay.com/deforestation_tropical.htm
A general article about why forests are being destroyed: http://www.mongabay.com/0801.htm
Information on oil palm plantations, a particularly threatening practice in Indonesia andMalaysia.

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