A large scale map is a map that depicts a small area of the Earth's surface with a high level of detail. Essentially, "large scale" means that a given feature on the ground (like a building or a road) is represented by a larger area on the map itself.
Understanding Map Scale
Map scale is the ratio of a distance on the map to the corresponding distance on the ground. It can be expressed in a few ways:
- Representative Fraction (RF): This is a ratio, such as 1:24,000. This means one unit of measurement on the map represents 24,000 of the same units on the ground.
- Verbal Scale: This is a statement, such as "1 inch equals 1 mile."
- Graphic Scale (Bar Scale): This is a line or bar drawn on the map that represents a specific distance on the ground.
Key Characteristics of Large Scale Maps
- High Detail: Because large scale maps represent smaller areas, they can show more features, such as individual buildings, small roads, streams, and elevation contours.
- Small Area Covered: They are best for showing localized areas like cities, neighborhoods, or parks.
- Large Representative Fraction: Large scale maps have relatively smaller numbers in the denominator of their representative fraction (e.g., 1:1,200 is a larger scale than 1:250,000).
- Examples: City maps, topographic maps, and engineering plans are typically large scale maps.
Comparison to Small Scale Maps
In contrast to large scale maps, small scale maps depict large areas (like countries or continents) with less detail. Small scale maps have larger numbers in the denominator of their representative fractions (e.g., 1:1,000,000).
| Feature | Large Scale Map | Small Scale Map |
|---|---|---|
| Area Covered | Small | Large |
| Level of Detail | High | Low |
| RF Example | 1:1,200 | 1:1,000,000 |
| Use Case | City planning, surveying | World maps, atlases |
Importance of Scale
Choosing the appropriate map scale is crucial for the task at hand. If you need detailed information about a small area, a large scale map is essential. If you need a general overview of a large region, a small scale map is more suitable.
