: MAP READING AND INTERPRETATION
EVERYBODY KNOWS HOW TO READ A MAP, WHY DO WE NEED TO DO
When you set up a field experiment, it is essential to know how to get as much detailed information
You need to know how to: 1) find and recognize a sampling site, 2) determine the easiest
route to the site, 3) recognize high and low areas to determine water flow direction, 4) measure
distance to be traveled, not just in a straight line, but up and down hills and around corners, and 5)
describe, by simple means, the location of special features on a site.
WHAT TYPE OF MAP SHOULD WE USE?
There are a wide variety of maps such as political, statistical, or simply geographical; each has its
We are going to use a
7 1/2 minute
Topographic map or Quadrangle
Why is this map called a 7 1/2 minute series?
(Hint: Look at the latitude and longitude designations
at the four corners of the map)
The physical features of an area, whether natural or cultural, are called its topography.
map shows relief (ups and downs).
HOW DO I LOCATE
SITES ON A MAP?
hills, ridges, valleys, streams,
lakes, marshes, woods and
They also show
features) such as roads, trails,
cities, buildings, and fences.
provide vertical information
through the use of
on any one contour line have the same elevation above sea level.
Every contour closes on itself and
encloses an area either within or beyond the border of the map.
Contour lines never split.
lines will appear close together when expressing a steep slope, and widely spaced when expressing a
Not all contour lines are labeled with an elevation; the ones that are labeled usually
have a thicker line.
To find out the elevation of an unmarked contour line, locate the two heavy labeled lines on either
side of the unlabeled line.
Then count the number of unlabeled lines in between.
The unlabeled lines
are always spaced equally apart with regard to change in elevation.
For example, look at Figure 2-1.
Chapter 1 1
ure 3-1: Contour lines with and without elevation labels.