Scale and Distance Geography Notes

Institution: Venberg Senior High School
Department: Humanities and Social Sciences
Subject: Geography (Year 8)
Topic: Scale and Distance
Associated Reference Points: * 10 Gray Peak * Mt Marcy: $21,300$ * Data Points: $4$ , $1,200$ , $14,400$ * Region: TIO Range

Overarching Goals: * Convert scales effectively to calculate speed, time, and distance. * Identify various relief features on a map. * Apply mapping skills specifically to topographic maps.
Success Criteria: Students must demonstrate the ability to accurately apply mapping skills to an ATAR broadsheet.

Definition: Maps are physically small compared to the geographical areas they depict. Consequently, scale is the tool used to shrink the real world so it fits onto a piece of paper.
Variability: The specific scale of a map is determined by the size of the real-world area being shown and the physical dimensions of the map surface.
The Three Types of Scales: * Written Scale (Verbal Scale): This provides a text-based description of how a map distance translates to ground distance. * Example: "One centimetre represents thirty kilometres." * Linear Scale: This is a numbered line that functions as a ruler on the map. * Example: If $1\,\text{cm}$ on this line is labeled as $30\,\text{km}$ , it indicates the ground distance. * Ratio Scale (Representative Fraction): This expresses the scale in pure numbers without specific units. * Example: $1:3,000,000$ . * Explanation: This signifies that $1\,\text{unit}$ on the map equals $3,000,000$ of the same units on the ground. For instance, $1\,\text{cm}$ on the map represents $3,000,000\,\text{cm}$ . Since $3,000,000\,\text{cm} = 30\,\text{km}$ , it matches the previous examples.

The standard output for map distance responses is kilometres ( $\text{km}$ ).
Maps may provide scales in centimetres ( $\text{cm}$ ) or metres ( $\text{m}$ ), requiring conversion skills.
Conversion Metrics: * $1\,\text{kilometre} (km) = 1000\,\text{metres} (m)$ * $1\,\text{metre} (m) = 100\,\text{centimetres} (cm)$
Conversion Process: * To go from $\text{km}$ to $\text{cm}$ : Multiply by $1,000$ ( $\text{km} \rightarrow \text{m}$ ), then multiply by $100$ ( $\text{m} \rightarrow \text{cm}$ ). * To go from $\text{cm}$ to $\text{km}$ : Divide by $100$ (to reach $\text{m}$ ), then divide by $1,000$ (to reach $\text{km}$ ).

General Rule: The larger the scale, the higher the level of detail provided.
Large-Scale Maps: Show small areas in great detail. * Example: A map of a school on A4 paper. * Values: Scale of $1\,\text{cm} = 5\,\text{m}$ (Ratio $1:500$ ).
Small-Scale Maps: Show large areas with very little detail. * Example: A map of Australia on A4 paper. * Values: Scale of $1\,\text{cm} = 150\,\text{km}$ (Ratio $1:15,000,000$ ).
The Ratio Rule: Remember that the larger the ratio number, the smaller the scale of the map.
Visual Examples of Scale Variation (Atlanta Case Study): * Small Scale: $1\,\text{cm} = 940\,\text{km}$ (Ratio $1:94,000,000$ ). Shows the whole Southeast US/North Mexico. * Mid-Small Scale: $1\,\text{cm} = 370\,\text{km}$ (Ratio $1:37,000,000$ ). Shows regional context. * Mid-Large Scale: $1\,\text{cm} = 160\,\text{km}$ (Ratio $1:16,000,000$ ). Shows state-level detail. * Large Scale: $1\,\text{cm} = 13\,\text{km}$ (Ratio $1:1,300,000$ ). Shows city-level detail including local neighborhoods like Smyrna, Chamblee, Tucker, Mableton, Stone Mountain, Panthersville, and Forest Park.

Definition: Also known as calculating distance "as the crow flies."
Procedure: 1. Use a ruler or the edge of a straight piece of paper to mark the distance between two points (e.g., a church icon and a triangle icon). 2. Place the paper/ruler against the linear scale at the bottom of the map. 3. Read the real-life distance based on where the marks align with the scale numbers.
Guided Practice (Bunbury Topographic Map): * Measure distance: Myalup ( $\text{AR9703}$ ) to Marbalup ( $\text{AR9802}$ ). * Measure distance: Western Titanium Siding ( $\text{AR9698}$ ) to Ferguson Hill ( $\text{AR9999}$ ). * Measure distance: Worsley ( $\text{AR0001}$ ) to Benger ( $\text{AR9902}$ ).
Further Practice (Anglesea Topo Map - Skills in Geography, pg. 99): * Measure distance: Mount Ingoldsby ( $\text{AR5144}$ ) and Point Light Station ( $\text{AR4738}$ ). * Measure distance: Lookout ( $\text{AR5344}$ ) and Scrubby Hill ( $\text{AR5547}$ ). * Measure distance: Point Roadknight ( $\text{AR5442}$ ) and Police Station ( $\text{AR5445}$ ).

Definition: Necessary for measuring actual travel distance along roads or footpaths, which rarely follow a straight line.
Procedure: 1. Use a piece of string or the edge of a piece of paper. 2. Follow the curves and corners of the path, marking the paper and pivoting it incrementally as the path changes direction. 3. This effectively converts a complex curve into a series of very short, interconnected straight lines. 4. Once the entire path is marked, lay the string or paper against the map's linear scale to determine the total real-world distance.
Guided Practice (Bunbury Topographic Map): * Measure distance: Coalfields Road ( $\text{AR0001}$ ). * Measure distance: Boyanup Road West from $\text{GR982994}$ to $\text{GR969996}$ . * Measure distance: Leschenault Peninsula starting from Point Douro ( $\text{GR976014}$ ).