Title: Introduction to Map Reading
1Introduction to Map Reading
- GRC JROTC
- COL(R) ALEXANDER
2Outline
- Purpose
- Marginal Information
- Colors
- Terrain Features
- Conclusion
3Purpose
- To lay the groundwork for successful map reading
and land navigation by exposing the cadet to
basic information, significant color coding, and
terrain features used on maps.
4Marginal Information1 of 4
- Sheet Name
- Sheet Number
- Adjoining Map Sheets Diagram
5Marginal Information2 of 4
- Special Notes
- Declination Diagram
6Marginal Information3 of 4
- Scales
- Contour Interval Notes
- Grid Reference Box
7Marginal Information4 of 4
8Colors (x6)
- BLACK Man-made features (Buildings, roads,
grid-lines) - RED-BROWN cultural features (contour lines)
- BLUE Water features (Lakes, swamps and rivers)
- BROWN Relief features and elevation on older or
red-light readable maps (contour lines and
cultivated land) - GREEN Vegetation (forest, woods, brush,
orchards) - RED Man-made features (populated areas, major
highway roads, boundaries on older maps)
9Contour Lines Interval
- 1. Check contour interval
- 2. Find given elevation
- 3. Determine direction of slope
- 4. Count contour intervals.
Change in ELEVATION
10Contour Lines Interval
Lines that are farther apart (interval) GENTLE
SLOPE
11Contour Lines Interval
Lines that are close together (interval) STEEP
SLOPE
12Major Terrain Features (x 5)
- Hill.
- Valley.
- Ridge.
- Saddle.
- Depression.
H idden V alley R anch S alad D ressing
13Major Terrain Features1 of 5
- Hill An area of high ground
- - Concentric circles. The center of the smallest
circle is the hilltop.
14Major Terrain Features3 of 5
- Valley a stretched-out groove in the land,
usually formed by streams or rivers. - - U or V shaped contour lines. High ground on 3
sides usually with water flowing in the middle.
V or U points upstream.
15Major Terrain Features4 of 5
- Ridge This is a sloping line of high ground.
- - low ground in three directions and high ground
in one direction. Contour lines tend to be
U-shaped or V-shaped. The closed end of the
contour line points to lower ground
16Major Terrain Features2 of 5
- Saddle Low point between 2 areas of high ground
- - hour glass or figure eight contour lines.
X
17Major Terrain Features5 of 5
- Depression This is a low point in the ground.
- - Low ground or sink hole. Closed contour lines
that have tick marks pointing toward low ground.
18Minor Terrain Features (x 3)
- Draw.
- Spur.
- Cliff.
19Minor Terrain Features1 of 3
- Draw a less developed stream course than a
valley. There is essentially no level ground . - contour lines depicting a draw are U-shaped or
V-shaped, - pointing toward high ground.
20Minor Terrain Features2 of 3
- Spur a short, continuous sloping line of higher
ground, normally jutting out from the side of a
ridge. - - Contour lines depict the U or V pointing away
from high - ground.
21Minor Terrain Features3 of 3
- Cliff a vertical or near vertical feature.
- Contour line converge together into one
Carrying contour. The last contour has tick
marks pointing towards low ground. Sometimes
depicted by contours running very close or
touching.
22Supplementary Terrain Features (x 2)
- Cut.
- Fill.
23Supplementary Terrain Features
- Cut or Fill a man-made feature resulting from
cutting through high ground or filling low
ground. - Contour line extends the length of the cut (tick
marks point to roadbed) and fill (tick marks
point away from roadbed).
24Practical Exercise
8
9
6
6
1. 2. 3. 4. 5.
6. 7. 8. 9. 10.
25Practical Exercise Key
HILL VALLEY 3. RIDGE 4. SADDLE 5. DEPRESSION
6. DRAW 7. SPUR 8. CLIFF 9. CUT 10. FILL
26Summary
- Purpose
- Marginal Information
- Colors (x6)
- Terrain Features
- Major
- Minor
- Supplementary
27Conclusion
- Knowing how to read and understand maps are
valuable skills that can strengthen your
awareness, credibility as a leader, and help you
standout among your peers.
28Introduction to Map Reading