Map overview

The map is according to certain number rule, Operator system, generalize the space phenomenon of the map or other planets, in the form of two-dimensional or multi-dimensional, static or dynamic visualization, comprehensive summary, model simulation and other means to reduce the representation on a certain carrier, scientifically reflect the distribution characteristics of natural and socio-economic phenomena and their interrelationships.

A map is a superposition of one or more layers, and a layer is a reference to a Dataset and displays the Dataset in a particular style. The map defines the name, display style, field of view, Layer Status, layer order and other information of each layer, which will be saved together when Save Map. The Layer Style in the Map can be modified by modifying the Layer Style or making a thematic map. In Map, you can visually edit the Geometry in the layer, such as changing the position, size and shape of the object. These operations will be directly reflected in the Dataset corresponding to the layer. That is to say, editing the layer is essentially editing the Dataset associated with the layer.

Features of the map

There are three aspects of scalability produced by special mathematical rules: map projection, Map Scale and map orientation;
There is the intuitiveness produced by using map language to express things. All kinds of complex nature and humanity expressed on maps are realized through map language, which includes map symbols and map annotations;
The map must be scientifically generalized, and the reduced map can not accommodate all the phenomena on the ground;
Map has a complete symbol system, the main object of map is the earth, the earth has a huge number of geographic information, including natural and socio-economic phenomena, need a complete symbol system, in order to accurately express this phenomenon.
Map is the carrier of geographic information, which contains and stores a huge amount of information. As the carrier of information, it can be a paper map, a solid model, a variety of Digital Maps, or a tactile map.

Map classification

Map classification is to classify and distinguish according to the alignment of some characteristics and indicators of maps, which can be classified according to various standards and methods, such as map content, Map Scale, mapping scope, map use, map form, etc.

1. Classified by map content

According to the content of maps, maps can be divided into two categories: ordinary maps and thematic maps. Classification by content is the most basic classification of maps.

Ordinary map: refers to a map representing the appearance of geographical landscape, specifically, a map representing various natural phenomena and social and economic phenomena on the earth's surface with a relatively balanced degree of detail, such as the basic elements of the ground such as residential areas, transportation networks, water systems, topography, soil, vegetation and boundaries. At the same time, ordinary maps can be divided into topographic maps and geographical maps.
Thematic map: refers to a map that highlights one or several thematic elements according to professional needs. Thematic map is composed of thematic content and geographical basis. Thematic content refers to the natural or socio-economic phenomena and their related characteristics highlighted on the map; Geographical basis refers to the general map content used to indicate the spatial location and geographical background of thematic elements, mainly including longitude and latitude network, water system, boundary, residential areas, etc.
According to the different objects of thematic Map Cartography, it is mainly divided into natural maps and human, social and economic maps. Maps reflecting natural elements or phenomena belong to natural maps, including thematic maps of geology, geomorphology, geophysics, climate, hydrology, ocean, soil, vegetation, animals, etc; Maps reflecting the mistakes or phenomena in the economic and other fields of human society belong to human maps, including thematic maps of population, economy, industry, agriculture, administrative regions, transportation, Land Use, culture and so on. Since the 1970s, there has also been a kind of map reflecting the relationship between human beings and the natural environment, namely, environmental maps, including thematic maps of ecological environment, environmental pollution, natural disasters, natural protection and renewal, disease and medical geography, global change, etc.

2. By Map Scale

According to Map Scale classification, it can be divided into three types: large scale map, medium scale map and small scale map.

Large scale map: refers to a map with a scale of Greater than or equal to 1: 100,000, such as 1: 100,000, 1: 50,000, 1: 25,000, 1: 10,000, 1:5000 and larger scales. Ordinary and thematic maps, which can represent the terrain, surface features or certain thematic elements of the ground in detail and accurately, are often compiled on the basis of actual measurement or field investigation. It can be used for the planning of prefectures, counties and townships, the design and construction of engineering projects, and the detailed investigation or special study of specialties, and can be used for map measurement or as the basic data for the compilation of small and medium-scale maps.
Medium scale map: refers to a map with a scale less than 1: 100,000 and greater than 1: 1,000,000, such as 1: 250,000, 1: 500,000, etc. The content of its logo is relatively simple, and the general and thematic maps compiled from large-scale maps or satellite images can be used by national departments and upgrading agencies for overall planning and professional census.
Small-scale map: refers to a map of Less than or equal to 1: 1,000,000, such as 1: 1,000,000, 1: 1,500,000, 1: 2million, etc. As the scale of this map is small, the degree of content generalization increases, and the accuracy of the set is relatively reduced. It is used to show the general characteristics of the mapping area, as well as the general and thematic maps such as geographical distribution rules and regional differences. It is mainly used for semi-regular reference and popularization of scientific knowledge in the whole country or across provinces.

3. Classification by cartographic area

According to the classification of cartographic regions, it is generally divided according to the size of administrative regions, natural regions and different planets.

The map can be divided into World Map, hemispheric map, ocean map, continent map, country map, province map, county map, city map and other administrative division maps.
It can be divided into the Yellow River Basin, the Yangtze River Basin, the Qinghai-Xizang Plateau, the North China Plain, and the sea area map.
With the development of science and technology, besides the map of the earth, there will be maps of the moon, Mars or other planets.

4. Classification by map use

According to the classification of map use, that is, according to the scope of map users and the nature of maps used to solve specific problems, they are classified into various special maps. The special maps mentioned here are not a classification of maps, but can be ordinary maps or thematic maps.

General map: applicable to a wide range of readers, such as scale topographic map, geographical map, tourist traffic map, city block map, administrative division map, etc.
Special map: refers to the map made for special purposes according to the special requirements of a certain department. Its types mainly include teaching map, publicity map, navigation map, aeronautical map, aerospace map, navigation map, highway traffic map, tourism map, water conservancy map, agricultural map, environmental map, disaster map, planning map, engineering map, media map, etc.
Special maps: maps that are displayed only in unconventional forms or made of special media and materials in addition to paper media, including digital maps, Digital Maps, screen maps, multimedia maps, Internet maps, Stereo Maps, tactile maps, luminous maps, silk maps, handicraft maps, etc.