7/13/12

With many environmental science experiments, inquiry modeling is ideal for having students understand "big picture" concepts yet still get hands-on experiences.

Throughout the two weeks of CRELI (CT River Extended Learning Institute), topics involving water in the environment were modeled using various activities. These models were then related to real world examples in the field.

Day 1 - Drop in a Bucket

The class was only 45 minutes long as opposed to the normal 90 minutes. The modeling activity reflects this. We started first with a warm-up journaling activity in which students answer the following questions, then students led the discussion of the answers to those questions.



Student were then introduced to the activity. The title of the first activity is called "Drop in a Bucket". It involves students modeling the types of water available on Earth (salt, frozen fresh, frozen fresh, non-polluted drinkable). As you can see in the picture above, most students believed that about 20% or more of the water on the Earth was drinkable. This is far from the case. Each student was given 1000 mL of water in a beaker and were told "here is all of the water on Earth!" and that they need to separate this 1000 mL into each of the types of water on Earth as described above. The math skills needed include an understanding of percentages. Students first predicted the percentages and had to model their predictions. This worked as the practice for when they have to model the actual values. Students were not given a procedure to follow, but a problem to solve however they saw fit.

Here are some action shots of the students working on the activity.


In conclusion, I feel as though the activity worked well with modeling the amount of the types of water. An interesting thing happened when students had to model the actual amount of drinkable water. Because the actual amount is 0.003%, students had trouble measuring this amount. They were told that the clue is in the title of the activity. They quickly realized that to model this they needed one drop.

With students now realizing the type of how much water we have to work with, the next activity involved where our water comes from and how it moves.

Drop 2 - Topographic Maps

This class was the full 90 minutes so we could really delve into the sometimes difficult concept of topographic maps. To represent something 3-dimensional using a 2-dimensional surface involves some spatial intelligence. To introduce students to this topic, students started a journaling activity based on an interactive PowerPoint presentation. The presentation is located here.


Students then used the skills learned in the presentation to complete the day's problem of modeling a landscape with ridges, valley, hills, mountains, etc. and then creating topographic map of that model. Bins were filled with colored water to measured points of equal elevation.




To cement the concepts, the students were then taken outside and shown differing landscapes to relate them to how a topographic map of the outside would look like. The next activity involves building upon the differing elevations of topographic maps and relating them to the implications of the runoff caused by precipitation.

Day 3 - Surface Runoff

Furthering our modeling of how water moves through the environment, brings us to modeling surface runoff. To model this, students took a piece of paper to model their landscape. Because our landscape is not flat, students crumpled up their piece of paper as well as folded it. This caused every students' landscape to be different. The students were asked where on the landscape the water sources would be. Based on the previous activity, many students knew that the water is at the lowest elevation. These water sources were colored using a blue marker. To model the pollutants created from various sources (factories, agriculture, roads, etc.), students colored these in using different colored markers for each.


To model rain, students used a spray bottle to cause the pollutants to runoff in the "water".


For the next activity, students will be using their understanding of surface runoff and will be relating it to how water is filtered and made drinkable.

Day 4 - Water Filters

Thus far, students learned through modeling how little water is actually drinkable. From there, they learned how water moves through changes in elevation and thus comes to be contaminated by surface runoff.

To build off this further, students watched a video on how water treatment plants work.



After watching the video, students went to the CT River to gather a sample of water to test their self-made filter.


After this, students constructed their filters by reusing 2 L soda bottles. The bottoms were cut from the bottles and then varying layers were added including sand, activated charcoal, and gravel.


After this, the students tested their filters by adding the CT River water they collected earlier. The water was then collected and analyzed following the filtering.


For the next activity, students will then use this understanding to further their study of how water is filtered by nature compared to their self-made filters.

Day 5 - Erosion Boxes

For the last days of the week, students used erosion boxes to find out how nature's filter compares with their own. One of the erosion boxes used contained only gravel while the other erosion box contained dirt and grass.




The water from the grass and dirt erosion box is noticeably clearer than the gravel erosion box. Students hypothesized reasons for this including the roots of the grass and how much the plants hold the soil together.
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