Geographic Perspectives on Sustainability and Human-Environment Systems

Learning Activity: Biogas System Diagram


Biogas generators convert biological matter into natural gas that can be used for cooking, heating, or other purposes. Biogas generators were discussed in the Marten reading “What is Human Ecology?” (See the the subsection “Cooking fuel and deforestation in India.”) In addition, here’s an image showing the basics of how a biogas generator works:

Simple sketch of household biogas plant
Figure 2.9 Diagram of a Biogas Plant: Waste is collected, disgested in a holding tank where gas is tapped for use and the byproduct is a bio-slurry.
Credit: Work found at Wikipedia / CC BY-SA 3.0

This image shows the basic mechanics of a biogas generator, which is useful for the engineering design of a generator. But the image only shows the generator itself, without considering the human and environmental systems in which the generator exists. As the reading explained, the generator requires a lot more than just human, animal, and plant wastes in order to operate. It also requires the humans that will design, fund, and use it, plus the farms, residences, and other sources of the wastes involved. Meanwhile, the generator produces a lot more than just gas. It also produces trees via reduced deforestation, fertilizer for farms, and even changes in how many children a family might have. But the generator, also, doesn’t do all this by itself. These impacts also depend on other human and environmental factors. If we don’t keep track of all these factors, then we can make mistakes in our analysis of what’s going on, and end up causing things that we don’t want to happen. Can you imagine this happening with biogas generators? How so?

Given how many different components there can be in a system, and how many different interactions there can be between them, we’ll often find the same system diagrammed in different ways. Module 2 Learning Activity is designed to have you get some more practice analyzing systems and producing system diagrams. In this learning activity, we're going to take a closer look at the example of biogas generators in India. But first, here's a quick video that shows that biogas isn't just for India, but is also used in the United States.

The video (31 seconds) is of a 2011 Super Bowl commercial for General Electric, which was identified by a Spring 2011 GEOG 030 student. Current GEOG 030 students: please send course faculty any content ideas that you have! We're very happy to consider them!

Learning Activity Directions

Part I: Create your blog entry

  1. Watch this 5 minute video about biogas in India.
  2. Draw a system diagram that shows all linkages between the social and the ecosystem as discussed in the movie. Use the Drawing feature in Google Docs. (Need help setting up your Google Account?)
  3. Add arrows in the figure and write down the effect that each arrow represents, so you can trace the chain of effects through the village social system and ecosystem.
  4. In one paragraph of 200-250 words, answer the following questions:
    • What are the core ideas behind your diagram? In your explanation, try to incorporate one or two course concepts/terms covered in Module 2.
    • Compare your diagram to Figure 1.5 in the Marten reading “What is Human Ecology?”
  1.  In what ways are they the same?
  2.  In what ways are they different?
  3.  Why are there similarities and differences?
  4.  What can be learned by the comparison between the two diagrams that we might not have otherwise learned?

When your diagram is complete, within the 'Insert Drawing' window pull down the 'Edit' menu and save your diagram to your computer as a JPEG image. ('Edit' >> 'Download As' >> 'JPEG'). Make sure that your image filename contains your User Id so that it is unique from other posts and is not overwritten! (e.g., ' biogas_xyz123.jpg ').

Add an Entry

  • Go to the GEOG 030 course blog.
  • Log in via the button on the top left.
  • Under the "+ New" tab, click "Post"
  • Type or copy and paste your entry into the editor.
  • Click on the appropriate Category.
  • Click Publish.

Use the 'Add Media' button at the top of the entry box to locate, upload and insert your diagram within your blog post. Include your comments to #4 above as a part of this blog post. (BE SURE to use the thumbnails option to make your image no larger than 500 pixels wide in your post so that viewers can see your entire diagram within your post.)

Don't Forget to Select the Module Category: M02

Categories are used to help grade the blog entries. You lose points for not including the category "M02". You must make sure that you have selected the M02 Category before you Save your entry.

Selection of module categories. Important to select M02 category for this module.

When you're done, click 'Save.'

Part II: Read and comment on other students' blog entries

Read other students' blog entries
After Part I has been completed, blog entries from all students will be available. Read through entries by about 20 other students to see some other ideas for systems diagrams. Pick two of these students to write comments on their entries. Pick students whose entries do not already have a comment on them. If all of the entries already have comments, then pick students whose entries only have one comment on them. Also pick students whose entries are interesting to you for any reason.

Post a Comment
Post a comment on the two blog entries you have chosen. Briefly introduce yourself. Include a link to your blog entry. Then respond to their entry in some way. Be sure to compare and contrast your system diagram with theirs. You might explain why their entries caught your interest, or say something else that comes to your mind. What you say does not need to be sophisticated in any way. The only requirement is for you to be polite and respectful.

The comment should be 4-6 sentences long, not counting the link to your entry. Below is a reminder on how to post your comment...

On a blog entry,

  • click on the title of the post so that just the one entry is displayed;
  • at the bottom of the entry display find the Leave a Reply section;
  • make sure to sign in if you are not already;
  • type in the text field as indicated for Comments;
  • include a link to your blog post;
  • then, click the Post Comment button.

More detailed information about blogging and commenting on blogs: Posting to the "Our Perspectives" Course Blog.

Grading Criteria

You will be graded on the quality of your participation. See the Unit 1 grading rubric for specifics on how this assignment will be graded (also accessible through “Resources” >> "Grading Rubric").