Introduction to Map Reading GRC JROTC COL(R) ALEXANDER Map Reading I

Outline Purpose Marginal Information Colors Terrain Features Conclusion Map Reading I

Purpose 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. Map Reading I

Marginal Information 1 of 4 Sheet Name Sheet Number Adjoining Map Sheets Diagram Sheet name- Center of the top margin. Generally title of prominent culture or geographic feature. Sheet Number- Upper right or lower left corner. Identifies the map Adjoingin Map Sheet Diagram. Lower right corner. Shows your map and those adjoining it w/ the same scale. Declination Diagram- Lower right margin. Show direction and relation ship between true, grid and magnetic north. Scales- Indicates the distance on the map equal to miles or kilometers. Contour Interval Note- represents the vertical distance between contour lines. Grid Ref Box- Id’s the grid zone and the 100k square meters. This will be used in the next two chapters. Unit Imprint- Agency responsible for preparing the map Legend- Data that Identifies symbols used on the map. Map Reading I

Marginal Information 2 of 4 Special Notes Declination Diagram Sheet name- Center of the top margin. Generally title of prominent culture or geographic feature. Sheet Number- Upper right or lower left corner. Identifies the map Adjoingin Map Sheet Diagram. Lower right corner. Shows your map and those adjoining it w/ the same scale. Declination Diagram- Lower right margin. Show direction and relation ship between true, grid and magnetic north. Scales- Indicates the distance on the map equal to miles or kilometers. Contour Interval Note- represents the vertical distance between contour lines. Grid Ref Box- Id’s the grid zone and the 100k square meters. This will be used in the next two chapters. Unit Imprint- Agency responsible for preparing the map Legend- Data that Identifies symbols used on the map. Map Reading I

Marginal Information 3 of 4 Scales Contour Interval Notes Grid Reference Box Sheet name- Center of the top margin. Generally title of prominent culture or geographic feature. Sheet Number- Upper right or lower left corner. Identifies the map Adjoingin Map Sheet Diagram. Lower right corner. Shows your map and those adjoining it w/ the same scale. Declination Diagram- Lower right margin. Show direction and relation ship between true, grid and magnetic north. Scales- Indicates the distance on the map equal to miles or kilometers. Contour Interval Note- represents the vertical distance between contour lines. Grid Ref Box- Id’s the grid zone and the 100k square meters. This will be used in the next two chapters. Unit Imprint- Agency responsible for preparing the map Legend- Data that Identifies symbols used on the map. Map Reading I

Marginal Information 4 of 4 Unit Imprint Legend Sheet name- Center of the top margin. Generally title of prominent culture or geographic feature. Sheet Number- Upper right or lower left corner. Identifies the map Adjoingin Map Sheet Diagram. Lower right corner. Shows your map and those adjoining it w/ the same scale. Declination Diagram- Lower right margin. Show direction and relation ship between true, grid and magnetic north. Scales- Indicates the distance on the map equal to miles or kilometers. Contour Interval Note- represents the vertical distance between contour lines. Grid Ref Box- Id’s the grid zone and the 100k square meters. This will be used in the next two chapters. Unit Imprint- Agency responsible for preparing the map Legend- Data that Identifies symbols used on the map. Map Reading I

Colors (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) Map Reading I

Contour Lines & Interval 1. Check contour interval 2. Find given elevation 3. Determine direction of slope 4. Count contour intervals. Change in ELEVATION Map Reading I

Contour Lines & Interval Lines that are farther apart (interval) = GENTLE SLOPE Map Reading I

Contour Lines & Interval Lines that are close together (interval) = STEEP SLOPE Map Reading I

Major Terrain Features (x 5) Hill. Valley. Ridge. Saddle. Depression. H idden V alley R anch S alad D ressing Map Reading I

Major Terrain Features 1 of 5 Hill: An area of high ground - Concentric circles. The center of the smallest circle is the hilltop. Map Reading I

Major Terrain Features 3 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. Map Reading I

Major Terrain Features 4 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 Map Reading I

Major Terrain Features 2 of 5 Saddle: Low point between 2 areas of high ground - hour glass or figure eight contour lines. X Map Reading I

Major Terrain Features 5 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. Map Reading I

Minor Terrain Features (x 3) Draw. Spur. Cliff. Map Reading I

Minor Terrain Features 1 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. Map Reading I

Minor Terrain Features 2 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. Map Reading I

Minor Terrain Features 3 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. Map Reading I

Supplementary Terrain Features (x 2) Cut. Fill. Map Reading I

Supplementary 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). Map Reading I

Practical Exercise 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. Map Reading I 8 9 6

Practical Exercise Key HILL VALLEY 3. RIDGE 4. SADDLE 5. DEPRESSION 6. DRAW 7. SPUR 8. CLIFF 9. CUT 10. FILL Map Reading I

Summary Purpose Marginal Information Colors (x6) Terrain Features Major Minor Supplementary Map Reading I

Conclusion 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. Map Reading I

Introduction to Map Reading GRC JROTC COL. ALEXANDER Map Reading I