What are the three elements of land?

A map is a graph or image that selectively represents some phenomena of the earth (or other planets) on a plane or a sphere in a two-dimensional or multi-dimensional form and means according to certain laws. It has a strict mathematical foundation, symbol system and text annotation, and can scientifically reflect the distribution characteristics of natural and socio-economic phenomena and their relationships by using the principle of map synthesis.

Three elements of a map

Scale, direction and legend are three elements of a map.

1, scale

Expressed by the formula: scale = distance on the map/actual distance. There are usually three representations of scales.

(1) number (also called digital scale), where the scale is expressed by proportion or fraction. For example:1:50,000,000 or1/50,000,000.

(2) Line type (also called scale), draw a line segment on the map and indicate the actual distance represented by 1 cm on the map.

(3) Text-based method: directly write down how many meters of field distance 1 cm represents on the map. For example, 1 cm on the map is equivalent to 500 meters on the ground, or one in 50,000.

2. Direction

Judgment method

(1) general orientation method, facing the map "up north and down south, left west and right east".

(2) Determine the direction according to the beacon. Generally, the arrow pointing to the beacon on the map indicates the true north direction.

(3) Determine the direction according to the longitude and latitude network, with longitude indicating north and south and latitude indicating east and west.

3. Myth; legend

Symbols used to represent various elements of geographical environment on maps, such as mountains, rivers, cities, railways, etc. , are called legends. The meanings expressed by these symbols are often marked on the corners of the map. Legend is the basic form and method of expressing map content, the language of modern maps, and a tool for reading and using maps. Map symbols generally include points, lines and figures with different sizes, thicknesses and colors. The design of symbols should be able to express the shape, size and position of ground scenes, and also reflect the qualitative and quantitative characteristics of various scenes and their relationships. Therefore, the legend is always designed as a geometric figure similar to the outline of the field scene.

map function

Map function refers to the efficiency and function of the map. According to certain rules, graphics or images that selectively represent some phenomena on the earth (or other planets) in two-dimensional or multi-dimensional forms or means on the plane or sphere have strict mathematical basis, symbol system and text labeling, and can scientifically reflect the distribution characteristics and their relationships of natural and socio-economic phenomena by using the principle of map synthesis.

Ancient maps were generally painted on parchment or slate, and the carrier of traditional maps was mostly paper. With the development of science and technology, electronic maps and other carriers have appeared.