Map, Air Photo, and Satellite Interpretation

Geography 380

Spring, 1999

Dr. Dorothy Freidel Department of Geography Sonoma State University, Rohnert Park, CA 94928 email: dorothy.freidel@sonoma.edu

LAB ASSIGNMENTS

	Go to Lab 1	Go to Lab 6
	Go to Lab 2	Go to Lab 7
	Go to Lab 3	Go to Lab 8
	Go to Lab 4	Go to Lab 9
	Go to Lab 5	Go to Lab 10

Lab 1:

Maps and Scales

I. Understanding Scale

This section is intended to help you gain a better appreciation for scale types and what typical sizes of scales look like. Use the series of maps in lab to find the following information about each map.

Map	RF Scale	Scale		Description of area covered by map	Map distance from Santa Rosa* to Melita (in cm)
		Verbal	Graphic
Santa Rosa 7 1/2'	1:	Y N	Y N	.	.
Santa Rosa 15'	1:	Y N	Y N	.	.
Santa Rosa 1° x 2°	1:	Y N	Y N	.	.
San Francisco Bay Region	1:	Y N	Y N	.	.

* For Santa Rosa, measure from the junction of Highways 101 and 12; for Melita, measure to the dot of the "i" in the name.

II. Scale Conversion

Perform the following scale conversions. Be sure to show your work, and include units in the problems.

1. Convert the verbal scale of '1 cm represents 80 km' to its RF.

 

 

 

 

2. Convert an RF of 1:35,000 to a verbal scale of '1 cm represents ___ km.'

 

 

 

 

3. Create a graphic scale (with units of kilometers) from an RF of 1:400,000.

 

 

 

 

4. Find the RF for this graphic scale:

 

 

 

 

 

 

III. Scale of an Unmarked Photo

 Several aerial photographs will be available in the lab. These photos will match an area on the Santa Rosa and Cotati 7 1/2-minute maps. Take a photo, find its location on the map, and calculate the scale of the photo. Refer to the example in the course supplement. Be sure to show your work.

Photo Number: ___________________

 

 

 

IV. Distance and Area from Map

1. Refer to the Altoona, PA 15-minute map in lab. Locate the crossroads in Figert, and the crossroads at Roots, just west of Bellwood. Measure the distance between them as the crow flies and then use the RF scale to convert it to ground distance in kilometers.

 

 

 

 

 

2. On the Jacksonville Beach, Fla, map, measure the area of urban development (pink) between 18th Ave. and First Ave. North, between First Street and the red dot and dash boundary line to the west. (Ask if you need help locating this block.). Then convert the map area to area on the ground in hectares. (Hint, use metric to measure the map, allowing easy conversion from square cm to hectares.)

 

 

 

 

 

 

 

 

V. Classification and Symbolization

1. Data Types & Symbols. Using the Santa Rosa 1:250,000 map, give at least five examples (out of eight boxes below) of data and symbol types. An example of ordinal point symbols, for instance, are city labels that vary in type size according to ranges of population.

	Point	Line	Area
Nominal	.	.	.
Ordinal	City labels (sized by population)	.	.
Interval/Ratio	.	.	.

2. Elevation Contours. Most topographic maps have two kinds of contour lines to indicate elevation. Major, or index, contours occur about every fourth or fifth contour with a darker tone. Minor contours show elevation between index contours. The elevation between contours (major or minor) is called the contour interval. Other contour lines that sometimes occur on maps are supplementary contours to show elevation changes in relatively flat areas of the map (shown with dotten brown lines), and depression contours, which show closed depressions by inward tick marks.

Check the maps listed in the following table for their elevation information:

Map and RF	Contour Interval	Interval of Major Contours	If Supplementary Contours, at what interval?
Jacksonville Beach, FL	.	.	.
Altoona, PA	.	.	.
Gilroy Hot Springs, CA	.	.	.
Santa Rosa, CA	.	.	.

3. Elevation Profile. Use the Santa Rosa 7 1/2-minute map to construct an elevation profile along a transect between two points: (a) the Drive-in Theater near the intersection of Highway 101 and Mendocino Avenue (in the northwest corner of the map), and (b) Rincon Valley Junior High School, in the north-central part of the map. Use the chart on the accompanying page.

You can do a profile in several ways. One of the best is to measure the distance from the origin (in this case, the Theater) to each contour line. Transfer this distance to the profile chart, and mark the elevation on the vertical. Once you have marked most of the contours, you can draw in a smoothed profile line.

 

 

Chart for Elevation Profile -- Photocopy will be provided

Go to Lab 2