Download Contour Mapping - Laboratory #10 - Geomatics | SUR 2101 and more Lab Reports Earth Sciences in PDF only on Docsity! Lab 10: Contour Mapping Purpose: In this lab you will learn how to determine elevations for contouring within an area that covers your parcel and a 5 meter buffer around it. Equipment needed: Automatic Level, Tripod, Level Rod, Wire Flags, Calculator, Field Book Procedure: 1. Office Procedure: a. Identify the longest side of your parcel and use this and a line approximately perpendicular to it as your grid axes. b. Using these axes as baselines draw a 5m x 5m grid in your field book following the example attached to this lab assignment. Start the grid 5m outside the parcel, and continue across the parcel until you are at least 5m outside the opposite side. Your grid does not have to be exactly orthogonal. c. Label the grid coordinates and create a table in your notes in order to facilitate organized data collection (see attached example). 2. Field Procedure: a. Lay out the grid by pacing and setting a wire flag every 5 meters. Ensure that you have the same number of flags per row on the ground as you do in your field book. b. Set up the level near the center of your parcel so that backsight and foresight is approximately balanced. c. 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. d. 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. Do not measure elevations at points within 10 meters of the instrument station. e. When all observable points have been collected, take a foresight reading onto another parcel corner (not the backsight point). There should be less than 3mm of error between BS-FS readings and the known elevation differences between the two corners. f. Once all points except those close to the instrument have been measured, move to a location at least 10m from your first set-up point. Move to an area where you will have balanced distances between your backsight and the remaining side shots. 1 g. Complete observations to all remaining points following the procedure described in c, d and e above. Your final foresight measurement should be to one of your parcel corners (not the one used for the backsight). h. When all measurements have been completed, return the equipment to the locker room. 2
