HW: Contour Mapping

Purpose:To learn how to determine elevations for contouring within an area that covers your parceland a buffer around it.

Equipment needed: Automatic Level, Tripod, Level Rod, Wire Flags, Calculator, Field Book

Procedure:

  1. Office Procedure:
  2. Identify a long side of your parcel and use this as your base line with one end point as your base point. A line perpendicular to it at the base point is your other grid axis. In the field, you can estimate the perpendicular direction by "eye".
  3. Using these axes as baselines draw a 50 ft x 50 ft grid in your field book following the example attached to this lab assignment. Start the grid outside the parcel, and continue across the parcel until you are outside the opposite side. Your grid should be perpendicular lines.
  4. Label the grid coordinates and create a table in your notes in order to facilitate organized data collection (see attached example).
  1. Field Procedure:
  2. Lay out the grid by pacing or approximate measurement along the perpendiculars, setting a wire flag or temporary marker every 50 ft. Ensure that you have the same number of markers per row on the ground as you do in your field book.
  3. Set up the level near the center of your parcel so that backsight and foresight is approximately balanced.
  4. Backsight to a parcel corner in order to establish the elevation of the level. The elevation data for the parcel corner can be found in your field book from the level lab.
  5. Once the elevation of the instrument is established, observe side shots to each of the flagged points. Simply place the rod on the ground next to each flagged point, plumb it, and take a reading on the rod. You only need to record the middle wire reading.
  6. When all observable points have been collected, take a foresight reading onto another parcel corner (not the backsight point). There should be less than 0.01 ft of error between BS-FS readings and the known elevation differences between the two corners.

3. Mapping:

a. Update your project map. Follow the methods shown in Lecture: Mapping4: Contouring on the course website. Update your project map adding your topographic points and contours.

Submit – In WebCT, upload:

1. Your field notes -- an Excel file that simulates the field notes shown below including a sketch of your grid. OR a *.xls or *.doc with an inserted scanned .jpg of your actual field notes similar to the example.

2. An updated AutoCAD map of the project site.



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