1. Map Reading Basic

2. Map Basics
Definition: A map is a mathematically determined representation of the Earth’s surface systematically plotted to scale upon a plane surface.
2/27/2019
NROTC Unit, UC Berkeley

3. Map Basics: Marginal Information (cont.)
PRIMARY SCALE
1000
2000
3000
4000
5000
500
METERS
EXTENSION SCALE
2/27/2019
NROTC Unit, UC Berkeley

4. Marginal Information (cont.)
Map Basics:
Marginal Information (cont.)
Declination Diagram
True North
Grid North
Magnetic North
2/27/2019
NROTC Unit, UC Berkeley

5. Map Basics: Declination Diagram
GRID NORTH
TRUE NORTH
Note: See Declination Diagram on Handout Map
MAGNETIC NORTH
2/27/2019
NROTC Unit, UC Berkeley

6. Map Basics:
Legend
Illustrates and identifies the topographic symbols used to depict prominent features on the map. Symbols on one map may not mean the same things on another map
2/27/2019
NROTC Unit, UC Berkeley

7. Map Basics: Legend
Includes all kinds of information, from the size/condition of roads to mines, chapels and other man-made features.
Note: See Legend on back of Handout Map
2/27/2019
NROTC Unit, UC Berkeley

8. Map Basics: Colors Black: Man-made objects Red: Main roads
Buildings, some roads, cultural, etc.
Red: Main roads
Also some special features
Blue: Water features
Lakes, rivers, ponds, ocean, etc.
Green: Vegetation
Forrest, orchard, etc.
Brown: Relief features
Contour lines.
2/27/2019
NROTC Unit, UC Berkeley

9. Determining Distance: Straight Line
The shortest distance between the two points
Lay a straight piece of paper between two points
Make two tickmarks on the paper corresponding to the centers of the two points
Move the paper down to the graphic scale
Make sure you use meters
2/27/2019
NROTC Unit, UC Berkeley

10. Determining Distance: Irregular Line
Used for winding roads, curved lines
Lay paper down so one edge is on the start point, make a tick mark at the start point and another where the edge of the paper leaves the center of the curve/line
Pivot the paper with the pencil on the second point
to align the paper with the center of the curve, make another tick mark when the paper leaves the center of the curve
Continue until measurement is completed
Transfer paper to the graphic scale to compute the distance
2/27/2019
NROTC Unit, UC Berkeley

11. Contour Lines: Basics
A contour line is a line drawn on a map representing an imaginary line on the ground along which all points are the same elevation
Indicates the vertical distance above or below a base plane
The vertical distance between two lines is the contour interval, found in the marginal data
Every fifth line is an index contour, it is shaded thicker and heavier
The lines in between are intermediate contours
Every line counted represents a change in elevation equal to the contour interval
2/27/2019
NROTC Unit, UC Berkeley

12. Contour Lines: Basics 10 2 1 x358 3 4 5 350 6 9 300 8 7
Supplementary Contour Line
Intermediate Contour Line
Index Contour Line
2/27/2019
NROTC Unit, UC Berkeley

13. Contour Lines: Determining Elevation
If a point is on a line its elevation is that of the contour line
For the estimation of elevation of a point between contour intervals is equal to 1/2 change in contour interval
A hilltop is 1/2 plus the elevation of the contour line around the hilltop unless otherwise stated
A depression is equal to the contour line around the depression minus 1/2 the contour interval
2/27/2019
NROTC Unit, UC Berkeley

14. Contour Lines: Elevation
350
300 1 2 3 4 5 6 7 8
x358 9 10
Elevation of Point: 7 = ? = ? = ? = ? = ? = ? = ?
2/27/2019
NROTC Unit, UC Berkeley

15. Relief & Terrain Features: Slopes
Evenly spaced and wide apart contour lines indicate a uniform gentle slope
Evenly spaced and close together contour lines indicate a uniform steep slope
Lines closely spaced at the top and widely spaced at the bottom is a concave slope
Lines widely spaced at the top and closely spaced at the bottom indicates a convex slope
2/27/2019
NROTC Unit, UC Berkeley

16. Relief & Terrain Features: Slopes
Uniform Gentle Slope
Uniform Steep Slope
Convex Slope
Concave Slope
2/27/2019
NROTC Unit, UC Berkeley

17. Relief & Terrain Features: Terrain Features
Hill: Indicated by closed loop. The ground slopes down in all directions
Draws: Less developed stream courses
ground slopes upward in three sides and down one side.
V points to higher elevation
2/27/2019
NROTC Unit, UC Berkeley

18. Relief & Terrain Features: Terrain Features
Ridge: A line of high ground with normally minor variations along its crest
Not simply a line of hills
The points of the ridge are higher than the ground around it
Finger: A continous line of sloping ground usually jutting from the side of a ridge
2/27/2019
NROTC Unit, UC Berkeley

19. Relief & Terrain Features: Terrain Features
Saddle: A dip or low point along the crest of the ridge
Cliff: A vertical or near vertical slope. So steep it is indicated by tick-marks pointing to lower elevation
2/27/2019
NROTC Unit, UC Berkeley

20. Relief & Terrain Features: Terrain Features
Depression: A low-point or sinkhole surrounded on all sides by higher ground
Tick marks point to lower ground
Each ticked contour circles represents a change in elevation equal to one contour interval
Valley: A stretched-out groove in the land
Usually formed by streams or rivers
2/27/2019
NROTC Unit, UC Berkeley

21. Relief & Terrain Features: Terrain Features
Cuts: places where high ground leveled off
Fills: areas where low areas are filled in
2/27/2019
NROTC Unit, UC Berkeley