Daily Objectives

Department of Earth Science |Northeastern Illinois University

INTRODUCTION TO EARTH SCIENCE
ESCI 121
Section 06
Fall 2008 Daily Objectives #24 (November 13, 2008) Dr. Sanders

By the end of today's class, you should be able to do the following:

w Explain how to retrieve the data you need for next week's homework.

TOPOGRAPHIC MAPS

w Maps: List the common elements that should appear on any map, and explain how to use and/or interpret them.
scale north arrow coordinate system key/legend title

w Explain the terms watershed, drainage basin, and divide.

w Finish the three topographic map activities that we started last time (below).

w Using the principles of contouring, participate in the following exercises (we will split into groups and rotate around to each activity):

ACTIVITY ONE

On the Galena, Illinois quadrangle, find the word “RAWLINS” in the middle of the map. Between the W and the L in RAWLINS flows an intermittent stream. Using tracing paper, outline the watershed (drainage basin) for this stream. To do this, you may wish to follow this strategy:

1) Place the tracing paper over the stream area and mark on the paper a few landmarks that appear on the map. When the paper slides around, you’ll be able to re-orient it using these landmarks.

2) Using blue pencil, trace the course of several streams that occur in the area, including the one we are working on.

3) Find the highest land between the streams and our stream of interest. Draw a very light line following the general location of this high area.

4) Now, get more precise: Locate the very highest places between the streams. Ask yourself, “If rain fell to the land surface here and started flowing downhill, which way would it flow?” If it goes in a direction that makes it end up in our stream of interest, it is part of that watershed! Draw the exact line showing the boundary of the watershed.

ACTIVITY TWO

Sketch a topographic map of the area carved in the sand on the stream table. When you are done, have the instructor check your map.

ACTIVITY THREE	Using the topographic quadrangles of Chicago Loop and Palos Park, find a place that illustrates the following features. Label and place sticky notes on the map to indicate the location of each feature.
	* a gentle slope * a steep slope * a closed depression * a round hill top * a ridge (elongated hilltop) * a lake * a benchmark	* a stream; find two places where contour lines cross the same stream and put sticky notes on the map to show both places. Tell what direction the stream is flowing. * a “Gaging Station” along a stream * a forested or undeveloped area (how can you tell?) * an urban area (how can you tell?)

Department of Earth Science | Northeastern Illinois University