What are maps used for?

1. Definition of map

A map is a graphic representation of the earth (or planet) on a plane. To be more precise: a map is a map of the earth (or planet) based on certain mathematical rules. ) natural phenomena and social phenomena are sketched on the plane with symbols through generalization and selection. And according to the purpose of each specific map, the geographical distribution and interconnection of several phenomena are shown selectively and with explanations. What a map represents is the abbreviation of objects and phenomena on the earth on a plane, but it is different from the sceneries, photos or drawings on the ground because it has unique characteristics:

There are many types of common maps, but Generally, according to certain mathematical rules, various natural or socio-economic phenomena are summarized and represented on a flat surface using a symbol system, and displayed in the form of a leaflet or an atlas for people to read and use. It has become a tool that people often use in their daily work, study, and travel. It is also an important means for studying geography and related sciences, and engaging in geography teaching. With the rapid development of science and technology and the mutual penetration of multiple disciplines, maps have continued to develop from content to form, from theory to method, from preparation to application, resulting in many maps that are not in conventional forms or reproduced with special materials. Maps, such as audio maps, digital maps, three-dimensional maps (including three-dimensional models, computer-aided three-dimensional perspective maps, raster maps, complementary color maps, etc.), braille maps, luminous maps, non-paper maps (including plastic maps, silk maps , pearlescent film map), etc., we collectively call them special maps. These special members of the map family have enriched and developed cartographic theory, expanded the breadth and depth of map applications, and played an important role in national economic construction, national defense construction, and daily life.

Three-dimensional maps

Maps generally only represent the flat features of the ground. To illustrate the characteristics of height distribution, it must be indirectly expressed by adding elevation data, drawing a contour map, or using shading and other methods. The three-dimensional map can directly use visual methods or with the help of instruments and equipment to observe the three-dimensional form of terrain and other geographical elements. There are many kinds of common three-dimensional maps at present, such as three-dimensional models, computer-aided three-dimensional perspective drawings, raster maps, complementary color maps, etc.

Three-dimensional terrain model

Traditional terrain models are often made of gypsum or sand, stone, and soil. This method and material has been used for a long time and has been gradually replaced by three-dimensional models made from plastic molds. Three-dimensional maps made of this new material are lightweight, strong, brightly colored, highly accurate, and clearly marked, and are very popular.

Computer-aided three-dimensional perspective drawing

This is a novel graphic that combines computer and traditional map production. It is based on the digitization of the original contour topographic map and is automatically drawn on a plotter using automatic drawing software that draws three-dimensional perspective views. It can be drawn from different perspective angles (0°-90°) and orientations (0° —360°) to obtain countless different three-dimensional perspective views of the same area. The method is simple, the graphics are novel, and the terrain features are obvious and prominent, but the measurement accuracy is poor. Three-dimensional perspective drawings can not only represent terrain elements, but are now widely used in various thematic maps. It represents the geographical location of geographical phenomena on a plane, and represents the distribution characteristics of thematic elements, such as population, environment, socio-economic factors, etc., in the form of three-dimensional columns, grids or trends.

Raster Map

We can see it on the covers of some albums or on the ruler patterns used by students. Some images are a lifelike three-dimensional landscape when viewed from a certain angle. or anaglyphs, which are raster stereophotographs. Some maps also have this feature. It uses a dual-lens camera to photograph the map or scenery of the three-dimensional model from different angles, and then overlays the two images together to obtain multiple sets of strip image pairs, which are then overlaid with one another. A virtual three-dimensional image can be seen through a grating film made of plastic. At present, due to insufficient imaging resolution and limited by the format and technology of taking photos, only some smaller maps representing general views can be produced.

Complementary color map

The complementary color map is made based on the actual situation of landforms and geographical landscapes, applying the parallax theory of the human eye and the principle of red and green complementarity. When a person observes a certain landform or geographical landscape with both eyes at the same time, the size, shape and brightness of their images on the retinas of the left and right eyes are basically the same. Since the human eyes observe the scenery from two different positions and angles, there is a dislocation in the position of the plane images formed on the retinas of the left and right eyes, that is, the parallax of the human eye. After being processed by the brain's visual area, A complete image with three-dimensional depth will be formed. At this time, with the help of red and green as a pair of complementary colors, different landforms and geographical landscapes such as mountains, rivers, buildings, scenic spots, etc. are printed into staggered and overlapping red and green colors. Graphics, you can get a three-dimensional map that seems messy to the naked eye, but looks like a lifelike three-dimensional map under red and green glasses. To use a complementary color map, just wear a pair of special red-green complementary color glasses, with one side red and one side green. Due to the color filtering effect of the red and green lenses, each eye can only see lines of one color. By reflecting the two images with parallax into the brain through the red and green eyes, a three-dimensional scene can be established.

Complementary color maps can show three-dimensional terrain vividly and vividly with eye-catching colors, making people feel lively and intuitive. Therefore, in geography teaching, students can understand various landforms (such as glaciers, river valleys) more intuitively and deeply. , karst, loess valleys, coasts, etc.), it can also provide tourists with a more comprehensive and intuitive overview of the tourist area.

Audio Maps

Paper is a common carrier of geographical information. Although through the reasonable design of graphics and the scientific use of colors, the load capacity of the graphics is considerable, but it needs to be The amount of geographical information represented on the map is larger, and is often limited by the format and scale. It can only selectively represent part of the information, and is mainly based on static geographical landscapes and their spatiotemporal distribution characteristics. Excessive emphasis on increasing the image load capacity can sometimes be counterproductive. One of the effective ways to increase the information capacity of maps and improve application effects is to change paper as a single carrier form. Therefore, tapes with high-density recorded information and additional devices were combined with conventional maps to form "audio maps." The audio map is designed and produced based on the principle that when people's audio and visual are in proportion and coordinated, it can help improve the ability to memorize. According to psychophysical research, among human sensory organs, vision transmits information the fastest, followed by hearing. If vision and hearing are mixed in a certain ratio, the temporary neural connections established in the cerebral cortex will be continuously replenished. , revise, improve, and finally form a complete object image concept. The audio map consists of an ordinary map, a pointer, a retrieval pad and a recorder add-on. The pointing device is an indicating rod composed of electronic circuits, which can be used to point to the feature symbols on the map and retrieve the description of the feature symbols from the tape; the retrieval pad is made of nylon, with printed on the surface that can be used as a map There are many squares for positioning, and there are retrieval grids and lead-out electrodes made of conductive resin mixed and offset in the interlayer; the recorder attachment has memory, addressing and control functions, and it is controlled by the signal output from the retrieval pad. When using the audio map, just place the map on the retrieval pad and position it according to the original positioning requirements. When the pointer points to a feature symbol on the map, the retrieval signal output by the pointer will pass through the lead electrode through the grid in the interlayer of the retrieval pad. Enter the VCR attachment and retrieve the corresponding commentary content from the tape. In this way, while observing the symbol of a certain feature on the map, you can also hear the explanation about the feature. As time goes on, the visual attention is focused on a certain feature symbol, and the auditory sense is constantly receiving new content information. At this time, the person is in a state of highly concentrated thinking, which is conducive to improving the reading and application effects of the map.

Digital Maps

Ordinary maps are printed on paper or other materials and can be read and measured directly. A digital map is a method that digitizes all the information that needs to be represented on the map and stores it in a computer without displaying graphics. When used, it is processed and analyzed for purpose, and then displayed in graphics and other forms (sections, process lines, etc.) or A special "map" that represents the answer data directly. Its data comes from various remote sensing images, ordinary maps, and thematic maps. Special programs are used to convert all this information into various types of data. It can be classified, combined, calculated, and processed according to user requirements, and then forms various series of different scales. A new pattern. Because digital maps are fast, accurate, rich in information, and novel and diverse, their uses are becoming increasingly widespread. For example, a traffic map represented in the form of a digital map can display the graphics of the required area in a timely manner as needed and adjust the scale to a sufficient level of resolution, providing ever-changing detailed road information. Another example is the Swiss National Atlas. All its information can also be stored on a specific 46-bit floppy disk for readers to call and read on a personal computer.

Braille map

Exclusively for the blind, it uses convex dots of the same size and different combinations to display features. This has been produced in many countries, ranging from small-scale maps such as Poland maps to large-scale maps such as the White House Tour Map compiled by the United States.

Glow map

Also known as luminous map and fluorescent map, it uses special color ink and ordinary printing methods to print the map content on special fluorescent paper. , with the help of invisible ultraviolet rays that continuously illuminate the picture, so that the content can be read clearly. There are many types of fluorescent maps, including fluorescent topographic maps, fluorescent navigation and aeronautical maps and other maps, which are widely used in night military operations or underground engineering.

Non-paper maps

According to the materials carrying map elements, there are various non-paper maps such as plastic (plastic sheet, plastic cloth, pearlescent plastic film, etc.), silk, polyester-cotton, etc. map. These maps are generally foldable, wear-resistant, lightweight, and not afraid of water. Among them, polyester-cotton maps are good materials for teaching wall charts and are increasingly loved and adopted by teachers; among plastic maps, transparent polyester plastic sheet maps , can often be used as the second base map of an atlas (such as making a plastic sheet base map of an administrative district, which can be overlaid on various thematic maps for professional analysis) or as a combination of a certain thematic map (such as using a plastic sheet to make a point method population map, analyzed as an overlay on other population maps).

The map is a "big family". If the introduction is based on the function of the map, then with the development of the national economy and the advancement of science and technology, there are many new varieties.

All these special maps and our common ordinary maps, thematic maps, and image maps have great application potential and play an increasingly important role in all walks of life, especially in science, culture, and education.