1 / 8

Unit 8 - Use of Maps

Unit 8 - Use of Maps. John Guthrie, USGS. Unit 8 - Use of Maps. Demonstrate the ability to shoot a bearing (azimuth) off a compass Explain the importance of knowing the proper declination of an area

asher-wells
Download Presentation

Unit 8 - Use of Maps

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Unit 8 - Use of Maps John Guthrie, USGS

  2. Unit 8 - Use of Maps • Demonstrate the ability to shoot a bearing (azimuth) off a compass • Explain the importance of knowing the proper declination of an area • Given a compass with proper declination and map (local area), determine an azimuth and the distance between two points.

  3. Topographic Maps • Show contour & elevation

  4. Topographic Terms and Features • Contour line • Contour interval • Line spacing • Wide = gentle slope • Close = steep slope • Slope direction • Lines point downhill on ridge tops • Lines point uphill where they cross drainages • You can get approximate elevation for any point on the map

  5. Organization and Scale • 15-minute series vs. 7.5-minute series • 7.5 most common • 1" on the map = 24,000" on the ground (.38 mile) • “Sectional” maps are composed of “quadrangles” • A sectional map might represent Colorado • Each quadrangle is named for a city or feature found within the quadrangle • Each quadrangle is 23,040 acres • Quads are further subdivided into “sections” for pinpointing locations

  6. Parts of aSection

  7. Public LandSurvey System

  8. TopographicMeasurements TOWNSHIP 36 Sections SECTION 640 Acres 1/2 SECTION 320 Acres 1/4 SECTION 160 Acres 1/8 SECTION 80 Acres ACRE 43,560 Sq. Ft. ACRE 208.71 ft. Square ACRE 100ft.x435.6ft ACRE 75ft.x580.8ft ACRE 50ft.x871.2ft ROD 16.5ft. CHAIN 66ft. CHAIN 100 Links CHAIN 4 Rods MILE 5,280 ft. MILE 320 Rods MILE 80 Chains

More Related