Where Does Water Go?

Introduction:

Water is one of the four main biogeochemical cycles that this lesson will cover.  A biogeochemical cycle is the complete cycle of a biological nutrient, such as water or carbon, through the environment.  The water we have on earth today is the same water that was here millions of years ago.  The same is true of carbon, nitrogen and phosphorous.  The focus of this lesson should be placed on water since it is easier to understand and more important to this unit.

National Standards Addressed:

The Structure of the Earth System under the heading Earth and Space Science is a very important concept in this lesson.  As the students learn about the cycles of the different elements they will begin to see a number of reasons why our earth is structured the way it is.

As a teaching standard, construction in the classroom, is one that would work well with this lesson.  With this lesson it is possible to allow students the opportunity to do a science project to relate to this lesson.  Having the students make dioramas and posters or other representations of these cycles would make the subject more easily understood.

Objectives and Benchmarks:

This lab will show students how some of the elements important to life are recycled in a constant and ongoing cycle.  Upon completion of this lesson students will be able to draw simple representations of each of the four cycles and be able to explain what is happening in each.

Materials:

Overheads or Handouts with Carbon,  Nitrogen,  Phosphorous and Water Cycles

Blank Paper            Colored Pencils or Markers

Procedure:

Begin this lesson by explaining to students that the water we drink today is the same water that has been around forever.  This is because water is constantly being cycled throughout our natural world.  Go through the different cycles with the students, pausing frequently to answer any questions.  After all of the cycles have been covered, have the students form groups and choose one cycle to draw a poster of.  Go around the room to ensure accuracy and to answer any questions.  

Things to Consider:

What is the driving force behind each cycle?

How could the phosphorous cycle be harmful to lakes?

What happens when we contaminate the oceans and rivers with waste?

Possible Integration:

This lesson is primarily an earth science lesson but could also be integrated into an art lesson by having the students draw much more detailed depictions of the various cycles.

It would also be possible to integrate this lesson into a chemistry course.  Look in-depth at the chemistry behind the various stages of each cycle and the chemical properties of each change.

Critical Concepts:

Biogeochemical Cycle   Carbon             Nitrogen            Phosphorous