1, meaning of geographical scale formula:
① "one inch, three minutes and five minutes": refers to the fact that on a large-scale map, the actual ground distance represented by one centimeter is relatively short, about one inch, three minutes and five centimeters.
② "One foot short": Metaphorically, on a map with a small scale, the actual ground distance represented by one centimeter is longer, about one foot.
③ "One meter is the length": The "meter" here refers to the internationally used unit of length, and the actual ground distance represented by one centimeter is one meter.
④ "1: 10000": This means that on the map with the scale of1:10000, the actual ground distance represented by one centimeter is10000 cm, that is,1000 meters.
⑤ "One centimeter on the map": This sentence means that on any scale map, one centimeter represents the actual ground distance.
2, the definition of geographical scale:
Scale is the ratio of the length of a line segment on the map to the actual length of the corresponding line segment on the ground. It can also be understood as the division relationship between the distance on the map, the actual distance and the scale, and the formula is: scale = distance on the map/actual distance.
The role of geographical scale:
1, the necessary mathematical basis for mapping and using maps:
Scale is an indispensable part of map making, which provides the mathematical relationship between the map and the actual ground, making it possible to make and use the map.
2, reflect the measurement accuracy of the map:
The scale directly affects the measurement accuracy of the map. The larger the scale, the higher the accuracy of the map, and vice versa.
3. Reflect the details of the map content:
The scale is closely related to the details of the map content. Generally speaking, large-scale maps have detailed contents and high geometric accuracy, and can be mapped on maps. Small-scale maps are universal and not suitable for cartography.
4. Decide what to display on the map:
The scale also determines the types and details of geographic information that can be displayed on the map. For example, large-scale maps can display more detailed geographic information and data, such as topography, buildings, vegetation and so on. Small-scale maps are more suitable for displaying macro geographic information, such as countries and continents.