Classroom Activity

Objective:  The purpose of this lab is to utilize a topographic map to delineate a watershed and determine the percent of the various land uses in the watershed and their impact.
 
 

Materials:

    Topographic maps of the area in question.

    Watershed CD or Aerial maps of the region ( In the scale of the topographic map).

    Acetate overlay

    Various color grease pencils

    Scissors

    Scale
 

Method:

    1.  Outline the tributaries on the topographic map that lead into the watershed.

    2.  Outline adjacent tributaries in different watershed in the surrounding area with a different color.

    3.  Outline the lake or stream in the watershed.

    4.  Using the elevation lines on the topographic map, decide on the boundaries of the watershed by locating the highest areas and direction of flow.  Make note of any roads since many times they are used as boundaries for a watershed.

    5.  After the watershed boundaries have been decided upon outline the watershed on an acetate overlay.

    6.  Fill in the various land uses  using the watershed CD or and aerial photograph that indicates the land uses.  Use a different color wax pencil for each land use.  Your land uses should be broken down into Residential, Commercial, Agricultural, Forest, and Recreational.  Include a key.

    7.  Cut out the land uses and mass each individual use and compare this to the total mass of all the land uses.  This will give you the percentage of each land use.

 
Analysis:
 
1.  List the percentages of each land use.

2.  Describe the major environmental impact of each land use.

3.  Design an experiment to test the impact of each major land use. Choose at least eight test sites along the watershed.

Extension:

With teacher guidance implement experiment.  Test as many sites as possible and compare results with predictions.