Year 8 Geography: Map Skills

• Year 8 Geography skills revision

Map Interpretation and Types

• Maps represent a part or the whole Earth's surface
• Types of Maps:
  • Physical
  • Political
  • Topographic
  • Thematic

BOLTS - Map Reading Acronym

• Acronym used when reading maps
• B = Border: the feature around a map
• O = Orientation: using compass directions to find your way around a map
• L = Legend: identifies boundaries, roads, buildings, agriculture, industry, and places of interest on a map
• T = Title: a general idea about the information a map stores
• S = Scale: allows a reader to calculate the size, height, and dimensions of features

Scale

• Scale is the ratio between real-life sizes and their representation on a map
• For a 1:50,000 scale map, 1 cm on the map represents 50,000 cm (500 meters or 0.5 kilometers) on the ground
• Represented in three ways:
  • Linear scale: a line divided into sections representing distance which requires a ruler to determine scale
  • Numerically: a ratio where 1:100,000 means 1 cm on the map equals 100,000 cm (1 km) on the ground
  • Sentence: for example, "1 cm represents 1000 meters"

Direction

• Direction from one place to another is found using a compass
• Four cardinal points: North (N), South (S), East (E), West (W)
• Cardinal points divide to form 8-point and 16-point compasses

Topographic Maps

• These maps show:
  • Relief
  • Land height above sea level (using contour lines)
  • Walking tracks
  • Water tanks
• Map features are explained in a legend or key

Grid References

• Lines form a grid pattern to pinpoint locations are divided into numbered squares
• Grid squares are usually one square kilometre in area
• Squares used to give a place a four or six-figure grid reference
• Horizontal lines called Northings
• Vertical lines called Eastings
• Eastings number from west to east
• Northings number from south to north
• Area Reference (AR), a four-figure numerical is a location point made up of a two-figure eastings reading and a two-figure northings reading
  • Example: 0467
• Grid Reference (GR), a six-figure numerical is a location point made up of a three-figure

Contour Lines

• Indicate land height above sea level
• Contour lines close together: a steep slope
• Contour lines widely spaced: a gentle slope

Recognizing Features from Contour Lines

• Recognise features from patterns made by contour lines
• Contour lines far apart: a small change in height over a given distance, indicating a gentle slope
• Contour lines close together: a large change in height over a given distance, a steep slope

Spot Heights

• Spot height features:
  • A dot point and a number
  • A triangle and a height value
• Local Relief: the difference in height on a line drawn between two points
• Aspect: the direction a slope is facing

Latitude

• Lines are imaginary, running around the Earth's circumference parallel to each other
• Lines are measured in degrees north (N) or south (S) of the Equator (0°)
• Equator divides Earth into northern and southern hemispheres
• North Pole at 90°N
• South Pole at 90°S

Longitude

• Measured in degrees east or west of the prime meridian (Greenwich, London at 0°)
• Each line is a meridian numbered east to west from the prime meridian at 0° to 180° (International Date Line)
• Lines are not parallel, meeting at the North and South Poles

Latitude and Longitude:

• When writing coordinates, always write latitude before longitude

Parallels of Latitude

• Run across the map from east to west
• There are 5:
  • Equator
  • Tropic of Cancer
  • Tropic of Capricorn
  • Arctic Circle
  • Antarctic Circle

Meridians of Longitude

• Run up and down the map from north to south
• There are 2:
  • Prime Meridian at 0°
  • International Date Line (IDL) around 180° in the Pacific Ocean

Synoptic Charts and Weather Elements

• Synoptic charts display weather elements at a specific time using isobars
• Isobars:
  • Lines on weather maps connecting places with equal air pressure
  • Enclose features called "cells," indicating high or low pressure areas
  • Show relationships between air pressure, wind direction, and wind speed
• High pressure: fine, clear, stable weather
• Low pressure: cloudy, unsettled weather with a chance of rain
• Winds around a high-pressure system: anticlockwise (Northern Hemisphere)
• Winds around a low-pressure system: clockwise (Northern Hemisphere)

Synoptic Charts; Pressure Systems and Fronts

• Low pressure systems: isobar numbers decrease towards the centre, indicating an unstable atmosphere, cloudy skies, rain, and strong winds
• High pressure systems: isobar numbers increase towards the centre, indicating gentle winds, clear skies, and little chance of rain
• Cold fronts: cold air overtakes warm air, causing temperature to fall, rain, and wind direction changes,

Synoptic Charts; Wind

• Lines point to where the wind is blowing towards a location
• The wind direction is based on where it originates
• The wind speed is measured by a tail and key
• The closer the isobars, the stronger the wind