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Maps. What do we need in order to read a map?. Direction Scale Legend. Types of Maps. Road Maps. Shows people how they can travel form one place to another Shows where the main highways are and where small country roads are. Shaded Relief Map.
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What do we need in order to read a map? • Direction • Scale • Legend
Road Maps • Shows people how they can travel form one place to another • Shows where the main highways are and where small country roads are.
Shaded Relief Map • Shows the shape of the land- mountains, valleys, rivers and lakes
Topographic Maps • Show a two- dimensional representation of a portion of the three dimensional surface of the earth.
What is a topographic map? • a map showing topographic features, usually by means of contour lines. • Graphic representation of the surface features of a place or region on a map, indicating their relative positions and elevations.
Land Height • Elevation- is the vertical distance above or below mean sea level. • Relief- is a representation of the shapes of hills, valleys, streams or terrain • CONTOUR LINES
Contour Lines Contour lines join points on a map that are of equal height above sea level
Contour Lines • How high above sea level is point X? • 50 m • How high above sea level is point Y? • 125m
Contour Lines • On the above map, the highest point is shown with a dot. • This is called a spot height.
Rules of Contour Lines • A contour line must never divide or split. • A contour line must never simply end. Somewhere the two ends of a contour line must join to enclose an irregularly circular region. • A contour line must represent one and only one elevation.
Rules of Contour Lines • A contour line may never intersect other contour lines. • Contour lines forms a V pattern when crossing streams and it always points upstream. • Closely spaced contour lines indicate a steep slope; widely spaced lines indicate a gentle slope.
Rules of Contour Lines • Concentric circles of contour lines indicate a hilltop or mountain peak. • Concentric circles of hashed contour lines indicate a hollow or closed depression.
Contour Intervals • A set distancebetween contour lines on a map. • Ex. A 100 interval would mean that you have lines showing 100m changes in elevation between them.
Question • So, what is the contour interval for this island? • 50m
Drawing Contour Lines • Where would X and Y be on this map?
Drawing Contour Lines Drawing Contour Lines
Map Symbols Topographic maps usually have a separate sheet with an explanation of map symbols. There is no room on the map for all the symbols 13 Sample page from USGS Topo Map Symbol Pamphlet
TOPOGRAPHIC MAP DESCRIPTION Five basic colors are used for Topographic Maps. Brown (Contour Lines: shows elevation) Black (Man Made Features: Buidlings, Roads, Trails) Blue (Water Features: lakes, rivers) Green (Vegetation: forests, other) Red (Highway and Land Grids) Three minor colors Pink (Built up area, civilization) Purple (Updated Map Information) White: no forests, might be farmland, meadows etc… PART 1 Basic Land Navigation
PART 1 Basic Land Navigation cem Map Symbols Symbols are used to represent the natural and man-made features of the earth. It is a map language that is simple to read and understand. BUT you must first know what the map symbols represent, in order to understand, read and speak map language to others.
PART 1 Basic Land Navigation Woods Scrub Orchard Vineyard Map Symbols VEGETATION Mangrove
PART 1 Basic Land Navigation Marsh or swamp Rice field Land subject to inundation SUBMERGED AREAS AND BOGS Submerge marsh or swamp Wood marsh or swamp Submerge wood marsh or swamp
PART 1 Basic Land Navigation Map Symbols Intermittent stream Perennial lake or pond Intermittent river Perennial stream Perennial river Small falls; small rapids Canal Large falls; large rapids Intermittent lake or pond Dam Dry lake RIVERS, LAKES, AND CANALS Well or spring
PART 1 Basic Land Navigation 15 18 12 13 19 16 20 17 14 Highway Road Dirt Road Trail Buildings Built-up Areas Airports Bridge Landing Strip Gravel Pit School Foot Bridge Church Mine Cemetery cem Power Lines Railroad MAN-MADE FEATURES and HIGHWAY & LAND GRIDS Map Symbols Land Grids