Reference no: EM133096979

Exercise - Topographic Map Basics

Topographic Map Exercise

1) What is the publication date of the USGS Valley Head topographic map (i.e., quadrangle) that is provided with this exercise?

2) The names of the adjacent quadrangles are printed along the boundaries of the Valley Head map. List the names of the other maps that lie off to:

a) the east

b) the NW corner

3a) What are the latitude and longitude coordinates of the NW corner of the Valley Head map?

b) What are the latitude and longitude coordinates of the SW corner?

c) What is the difference in latitude (in minutes and seconds) from the northern border to the southern border of the map?

d) Determine the difference (in minutes and seconds) in longitude from the western border to the eastern border of the map.

4a) What is the representative fraction (i.e., scale) for this map?

b) What is the contour interval?

5) What is the exact elevation of the hill at the following location: SW¼, NW¼, section 9, T5S, R10E?

6) Give the complete Township and Range coordinates of the radio tower in section 15 in the northern part of the map.

7) In which compass direction from the radio tower is the slope the steepest? Explain how you know.

8a) What is the approximate elevation of the radio tower in meters?

b) Convert this elevation into feet.

9) Find the approximate elevation of the following two points and convert it into feet:

a) Little River Church located SE of the radio tower - base your estimate on the black rectangle that represents the building.

b) The stream labeled "East Fork Lookout Creek", which is located directly downslope from the radio tower. Determine the stream elevation near the letter "k" in the word "Lookout".

10a) Using a ruler and the map scale (1:24,000), determine the actual distance in miles between the points listed below. (If you are looking at the map on a computer screen, you'll need to determine the map scale for whatever magnification factor you are viewing it at. To determine this scale, simply take a ruler, and on the screen, measure the width of the nearest township and range section. Since sections are 1 mile wide, your map scale would be x inches = 1 mile).

a) Radio tower and the church.

b) Radio tower and East Fork Lookout Creek--again, use the letter "k" in the word "Lookout as your reference point.

11a) In the space below, make a cross-sectional sketch of the land surface between East Fork
Lookout Creek and the Little River Church.

b) In the subsurface view of your sketch, use a ruler to draw a vertical line up to the radio tower. Next, draw a horizontal line from the stream to this vertical line, then draw another horizontal line from the church. You should now see two right triangles, with the hypotenuse in each case being the slope of the land surface.

c) On your sketch, label the elevations (in feet) that you determined for the stream, radio tower, and church.

d) Add to your sketch the horizontal ground distances (in miles) between the radio tower and the church, and the radio tower and stream.

12a) Using your sketch as a guide, calculate the slope of the land surface in feet/mile between the radio tower and the church. Here you should first write out the equation, then plug in the appropriate numbers.

b) Now calculate the slope between the radio tower and the stream.

c) Write the slope values, including units, next to the corresponding slopes in your sketch. Does the steepness of the slopes in your sketch reflect the values you calculated?

13a) Convert the slope values you found in question 12 into the unitless form called grade.

b) Which form of slope do you find more meaningful, grade or feet per mile? Explain why.

14) Examine the way in which the contour lines cross the East Fork of Lookout Creek. Based on this, explain what compass direction this stream is flowing.

15) Find the river named "Middle Fork Little River" located in the eastern part of the map.
Examine all the tributaries that make up the drainage network for this stream. Based on the pattern you see, explain what compass direction that the main (i.e., trunk) stream must be flowing.

16) Find the tributary labeled "Stillhouse Branch", located to the west of the main trunk of Middle Fork Little River. Suppose there is a big moonshine operation at the red label for section 25 (T5S, R10E), and the still explodes, sending a thousand gallons of moonshine into Stillhouse Branch.

a) Would it be possible for the contamination to reach Blalock Creek, located just to the NE? Explain why or why not.

b) Could the contamination reach Lake Lahusage to the south? Explain why or why not.

17) Find the strip mine located in SE¼, section 1, T6S, R10E. When it rains, can contaminated runoff from this mine reach Anna Branch? Explain why or why not. Hint: draw a sketch of the land surface between Brush Creek and Anna Branch.

18a) In which direction does the West Fork of the Little River flow? (This is the large river in the middle of the map.) Explain how you know.

b) Find where the 450m and 500m contour lines cross the river. Determine the gradient of the river in feet/mile between these 2 points. Be sure to measure the actual curved distance of the stream, not the straight-line distance. (If you are looking at the map on a computer screen, you'll need to determine the map scale for whatever magnification factor you are viewing it at. To determine this scale, simply take a ruler, and on the screen, measure the width of the nearest township and range section. Since sections are 1 mile wide, your map scale would be x inches = 1 mile).

c) Find DeSoto Falls along this reach of the stream. How do you think the stream gradient here at the falls compares to average value you just calculated?

Attachment:- Topographic Map Basics.rar