Topographic Maps

15 September 2014

Why are there two roads from Louberg to Luluville?

And the answer why there are two roads from Louberg to Luluville is…

Dingle Rd. goes around the mtns. while Bo Ring Way goes UP & OVER

the the mtns.

Topographic map: map that shows topography & features

found on the earth’s surface --Examples?

RELIEF: difference in elevation betw. two points

CONTOUR LINE: connects points of EQUAL elevation (BROWN LINE)Elevation: land-based height above sea level

A map with topographic

contours.

Sea Level =0 feet

CONTOUR INTERVAL: distance in elevation between consecutive contour lines

The island from above.

II. Labeling Contours

Island with itsCONTOUR LINES.

Looking downfrom above.

Contour Interval = ?

Contour Interval(C.I.)=250 feet.

--Labeling EVERY line with an elevation getstoo cluttered.

Instead, we use an INDEX CONTOUR: every FIFTH line is labeled and thicker.

BENCHMARK: an exact point of elevation that can be marked with an X, +, or BM.

-indicate places where the elevation has actually

been surveyed

What’s the elevation of points A, B, & C? Which is the highest of the three? Which is the lowest of the three?

Notice: any place INSIDE a contour line is HIGHER than the contour line. Any place OUTSIDE a contour line is LOWER than the contour line.

III. The V Rule

*Contour lines bend to form a V when they cross a river. *The V points upstream.

-Therefore, the river flows the other way

Summary:

Spruce Knob, W.Virginia:

-Contour Lines?

-Contour Interval?-Index Contour?-Elevation of A & B? -Relief? *From A – B?-Benchmark?-V-Rule?

AB

NOTES ARE FINISHED FOR TODAY (15 Sept. 2014)

Work on assignment until the bell.

IV. Depression Contours—Getting into and out of a hole.

17 September 2014

The highest point (1397’) is on the rim between its outer slopes and crater.

C.I.=200’

Contours betw. 517’ and 1397’ are fine. But, you cannot have a 1200’ line INSIDE a 1200’ line, and 1000’ line INSIDE a 1200’ line.

Everything insidea contour is supposed to beHIGHER than thecontour.

DEPRESSION CONTOUR: indicated with “teeth” called HACHURES.

Hachured contours:a point inside a contour is lowerthan the contour.

--A point outside a contour is higherthan the contour.

From the rim, the land goes down on BOTH sides—towards the outside of the volcano and inside the crater.

V. Contour Spacing and Steepness (Gradient)

NOTICE: the slope from atop Mt. Tipster is much STEEPER down to sea than the slope from atop Mt. Riddle down to sea.

NOTICE: where the slopes are STEEPER the contour lines are CLOSER. Where the slopes are GENTLER the contour lines are FURTHER APART.

What happens if you have a VERTICAL cliff?????!!!!!!!

With a cliff, the contours will come together and merge. THIS IS THE ONLY TIME CONTOURS TOUCH!

CI = 10’

?

THE END

Work on assignment for remainder of class.

17 September 2014