Applied Geomorphology Lecture Notes - University of South Alabama
Applied Geomorphology Lecture Notes - University of South Alabama
Applied Geomorphology Lecture Notes - University of South Alabama
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<strong>Applied</strong> <strong>Geomorphology</strong><br />
<strong>Lecture</strong> <strong>Notes</strong><br />
By David T. Allison
Topographic Maps<br />
Scale (Relational Fraction; Graphical)<br />
Elevation contours (Relative to M.S.L)<br />
Boundary (Latitude & Longitude)<br />
Color (Water bodies, Woodlands, etc.)<br />
Cultural Features (man-made features)
Scale<br />
Relational fraction<br />
• 1:24,000<br />
• 1 inch on the map = 24,000 inches in reality<br />
• 1 inch on the map = 24,000 inches x 1 foot/12<br />
inches<br />
• 1 inch on the map = 2000 feet<br />
• 1 inch on the map = 2000 feet x 1 mile/5280 ft<br />
• 1 inch = 0.378 miles
Graphical Scale<br />
Uses a graphical scale to indicate<br />
distances
Elevation Contours<br />
Contour lines (brown)<br />
• Based on aerial photographs analyzed<br />
stereographically<br />
• Must agree with benchmarks and spot<br />
elevations<br />
• Contour interval: elevation change between<br />
adjacent contours<br />
• Hachured contours indicate closed<br />
depressions
Construction <strong>of</strong> Topographic<br />
Contours<br />
Contours <strong>of</strong> any parameter use a simple<br />
proportionality rule<br />
Contours should “V” in the upstream<br />
direction across valleys.<br />
flow<br />
80<br />
x<br />
87<br />
x<br />
77<br />
x<br />
80<br />
x
Topographic contours in 3D
Topographic<br />
contours in 3D cont.
Contours: can delineate geological<br />
contacts
Topographic Map Boundary<br />
Always consist<br />
<strong>of</strong> lines <strong>of</strong><br />
latitude and<br />
longitude<br />
Contain tick<br />
marks <strong>of</strong> UTM<br />
and SPCS on<br />
103 30’ 103 22’ 30’’<br />
32 15’<br />
32 15’<br />
7.5’ Topographic<br />
Quadrangle border<br />
(1:24,000)<br />
the border<br />
32 7’ 30’’<br />
32 7’ 30’’<br />
103 30’<br />
103 22’ 30’’
Topographic Map Colors<br />
Brown: topographic contours<br />
Green: Forest and/or wetlands<br />
White: cleared areas (i.e. pastures, etc.)<br />
Black: Cultural features (buildings, roads)<br />
Red: Land <strong>of</strong>fice grid system (Township &<br />
Range system); Major road systems<br />
Magenta: Photo-revised areas<br />
Blue: water bodies
Topographic Map Examples
Map Coordinate Systems<br />
Land Office Grid system (Township &<br />
Range)<br />
Universal Transverse Mercator (UTM)<br />
State Plane Coordinate System (SPCS)
R2W<br />
Land Office Grid System<br />
R1W R1E R2E<br />
6 miles<br />
T2N<br />
T1N<br />
T1S<br />
6 1<br />
7 12<br />
18<br />
13<br />
19 24<br />
T2S<br />
30<br />
31<br />
25<br />
36<br />
State Capital<br />
36 square<br />
miles<br />
NW<br />
NE<br />
Legal description <strong>of</strong> location:<br />
NE ¼ , SW ¼, section 22, T2S, R2E<br />
SE<br />
Target location
Land Office Grid Example:<br />
Benchmark 212:<br />
• NW ¼, NE ¼, sec.<br />
36, T3S, R3W
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