week 02 - survey & navigation

Question 1

3 basic navigation measurements

Answer 1

• distance
• direction
• elevation (or change in)

Question 2

compass

Answer 2

• measures deviation from North
  
  • may include correction for magnetic declination
    
    • Seattle/Kenmore decl. = 16° 7’ E
• Ranger compass incl. mirror, to sight target while adjusting dial

Question 3

azimuths

Answer 3

• measure degrees, clockwise from N (0-360)

Question 4

bearings

Answer 4

• quadrants
• latitudinal hemisphere (N/S), then 0-90 toward long. direction
• 150° azimuth = S 60° E

Question 5

to go in a certain direction…

Answer 5

1. Dial in direction (under Fred)
2. turn body around until Red is in the Shed
3. follow Fred

Question 6

To determine direction to object

Answer 6

1. point Fred at object
2. turn dial until Red is in the Shed
3. read direction under Fred

Question 7

Distance…

Answer 7

• surveyor tape: record air temp. to account for shrinkage; hold level as horizontal dist. assumed
• chain = 66 feet
• pace = pair of left/right steps
• clinometer: measures angular slopes / changes in elev.

Question 8

Contour Maps…

Answer 8

• contour lines are equal elevation
• interval is diff. in elev. b/t two lines
• every 5th line darker, marked w/ elev.
• concentric circles: hill
• even spacing: uniform slope
• wide spacing: gentle slope | @ top of hill: flattop
• narrow spacing: steep slope/wall/cliff | @ top: pointed
• crossing/touching: overhang/cliff
• jagged: outcrops, cliffs, fractured areas
• V: streams/drainage, points uphill
• U: ridge, bottom of U points downhill
• circle + hatch lines: depression/pit/sinkhole

Question 9

the Rational Formula

Answer 9

Q = ACi

• Q: runoff, in cubic feet
• A: subwatershed in sq. ft
• C: runoff coefficient (runoff : total rainfall)
• i: rainfall intensity
  
  • usually reportined in./hr… convert to feet

values of C

• UBNA: ~.75
• Forest: .10
• Pasture: .20
• Cultivated soil: .50
• Pavment/roofs: .90

Question 10

impoundment

Answer 10

• something that holds water:
  
  • pond
  • wetland
  • detention
  • infiltration
• created by:
  
  • excavation
  • dike/levee normal drainage, causing water to back up
• calc. vol. of excavation
  
  • create cross-sections & calc area of each
  • Multiply the distance in feet between cross- sections times the average end area of any two adjacent cross-sections (???)