Geography 12: Mapping Skills
UNIT 2
October 9th, 2011
Objective

Let's look at our first topic under Mapping
Skills - Contour Lines.
Contour Lines

A contour line on a
map is a line that
joins points of equal
elevation.
Contour Lines

The contour line
represented by the
shoreline separates
areas that have
elevations above sea
level from those that
have elevations below
sea level
Objective

Lets review the basics of Latitude and
Longitude
Latitdude

(shown as a horizontal
line) is the angular
distance, in degrees,
minutes, and seconds of
a point north or south
of the Equator. Lines of
latitude are often
referred to as parallels.
Latitude
Degrees latitude are numbered from 0° to 90°
north and south
 Each degree of latitude is about 69 miles (111
km) apart

Longitude

(shown as a vertical line) is the angular distance,
in degrees, minutes, and seconds, of a point
east or west of the Prime (Greenwich)
Meridian. Lines of longitude are often referred
to as meridians
Longitude

The degrees continue 180° east and 180° west
where they meet and form the International
Date Line in the Pacific Ocea
Longitude and Latitude

To precisely locate points on the earth's
surface, degrees longitude and latitude have
been divided into minutes (') and seconds
Objective

Scale

A map represents
some portion of the
earth or sky on a
two dimensional
surface. The size of
the individual
features need not be
indicated if a map
scale is given
Planimetric Map

two dimensional
feature of the earth’s
surface.

eg road map, city
plan, drainage
network map, map
showing political
boundaries
Topographic map

shows three
dimensional features
of the earth’s
surface, that is, the
relief or topography
of the land surface
or ocean floor
through the use of
contour lines
Scale

Map scale expresses the relationship(ratio)
between distance on the map and the true
distance on the ground (In reality)
Every Map should have its scale clearly
indicated
 Ex: 1:90000

Geography 12: Mapping Skills
Lesson 2: October 22, 2010
Today’s Class
According my source in BC there would be no
reason to use a calculator on the Geography
Provincial exam
 Review Homework
 Scale
 Gradient
 Military Grid and Map Symbols
 Topographic map Interpretation
 Air Photo Interpretation

Gradient

Let's look at how to calculate gradient
which is a measurement of the steepness
of the land or simply slope
Military Grid
A method to locate points on a map.
 With this method, a system of
numbered lines is superimposed on a
map and position is stated by quoting
the numbers of the lines that intersect
at the point in question.

Symbols on a topographic map
Air Photo Interpretation

Let's look at some basic guidelines to assist
you in interpreting an air photograph
Feature Identification
Shape

Cultural features: - some

Natural features-- quite
easy to tell the
difference, for example,
between an orchard
(rows of trees with
regular spacing) and a
forest area with
irregular tree growth
features such as airport
runways have a distinctive
shape which make them easy
to identify
Pattern

formed by the repetition of a feature
eg farm fields, rows of trees in an
orchard, oil storage tanks at a refinery
Shadow

- high objects such as towers, chimneys,
bridges, or high buildings cast shadows
which help you to identify the object
Tone
Cultural Features
 - roads and tracks will usually have a
light grey tone as they are fairly
reflective of light
- railways: medium grey
- bridges: vary according to construction
material

Tone
Natural Features
 Water
- generally appears dark grey or black
since it absorbs much of the light

Tone

Vegetation
- most will vary from shades of grey to
black
Tone

Soil
- bare ground usually has a light colour
but the wetter it is, the darker the tone
Tone

Crops
- cultivated fields and fallow fields are
almost white in tone
Tone

General Guide
Spring: sharp, distinct field patterns due to
differences in tillage and crop development
Summer: dark tones for maturing crops
and heavily leafed trees
Fall: distinct field patterns because of the
various stages of crop development and
harvesting
Winter: when there is little or no snow
cover, tones are generally drab and dull
See Notes for Interpretation
 http://www.sd36.bc.ca/sites/semiah/mleziva/uni
t2/U02L09.htm


Homework