What is the representativeness of the above-ground bridge in China?

Bridges generally use: symbol] [,and the legend is as follows:

A, other bridge map symbol representation

1, railway bridge, in which black and white short columns represent railways.

2. Highway bridges and expressways are generally represented by a set of parallel lines.

3. footbridge

4. Cableway Bridge

Second, the map definition

According to a certain proportion, symbols, colors, text notes, etc. A graph used to describe the physical geography, administrative areas and socio-economic conditions of the earth's surface.

Map layout of China

Third, map classification.

(1) is divided into: world map, hemisphere map, continental map, ocean map, ocean map, ancient map,

National (regional) maps, provincial maps, city and county maps, etc.

(2) According to its special topics, it is divided into: natural map, population map, economic map, political map, cultural map and historical map. ? (3) According to its specific application, it can be divided into: reference map, teaching map, topographic map, aviation map, nautical map, coastal map, astronomical map, traffic map, tourist map, etc.

(4) According to its use form, it can be divided into: wall chart, desktop map, atlas (book) and so on.

(5) According to its manifestations, it can be divided into miniature maps, digital maps, electronic maps and image maps.

(6) According to its printing format, it is divided into: 16 format, 8 format, 4 format, folio, full sheet, two full sheets, three full sheets, four full sheets and nine full sheets.

(7) Classification by map: atlas, electronic map, three-dimensional map, satellite map, image map, etc.

(8) According to the contents of maps, maps can be divided into three types: ordinary maps, topographic maps and thematic maps.

Ordinary map is a map showing the main natural and socio-economic phenomena on the ground in the same degree of detail, which can comprehensively reflect the geographical characteristics of the mapping area, including water system, topography, soil, vegetation, residential areas, traffic networks, boundary lines and major socio-economic factors.

The difference between general geographical map and topographic map;

Mainly manifested in: map projection, framing, scale and representation method have certain flexibility, and the content represented is more general than topographic map with the same scale, and the geometric accuracy is lower than topographic map.

The topographic map refers to several basic national scales (1:5000, 1: 1 000, 1:25000, 1:50000,1:/kloc-

It is measured (or compiled) according to a unified standard and symbol system, and represents all kinds of geographical things in a comprehensive and detailed way. The geometric accuracy is high, which can meet the needs of various maps. It is the basic data for national construction and the original data for compiling other maps.

Thematic maps focus on the geographical distribution of one or more natural or socio-economic phenomena, or emphasize some characteristics of these phenomena.

Thematic maps have a variety of themes and serve a variety of customers. It can be further divided into natural maps and socio-economic maps.

Four, the basic elements of the map:

(1) direction on the map

(2) the scale of the map

(3) Legend on the map

Verb (abbreviation for verb) Map of China

A map drawn to define the territory of China.

? Topographic map of China

Geographical administration of China

China is located in eastern and central Asia, on the west coast of the Pacific Ocean. The distance between north and south is 5500 kilometers, and the latitude is 4915'; The distance from east to west is 5200 kilometers, and the span longitude is about 62. The time difference between the east and west ends is about 4 hours.

Administration is divided into 34 provincial administrative centers and administrative units, which are divided into three levels: province, county and township.

Sixth, the application of maps in daily life

Maps often used in people's lives include traffic maps (electronic maps), traffic and tourist attractions maps, weather forecast maps and so on. In order to travel conveniently, I mainly want to know the real-time road condition query, map information search, bus transfer query, driving navigation query, surrounding query, regional overview and so on.

Seven, electronic map

Namely a digital map. It is a visual real map.

Commonly used electronic maps are:

Google Maps, Baidu Maps, Gaode Maps, sogou Maps, etc.

Basic operation of electronic map:

Enter the map and click search, such as "Chengdu, Sichuan Province"; You can find specific hotels, schools, streets, communities, etc. It can zoom in and out of the map, enter the real scene, print the map, measure the distance, query the bus lines and other operations.

Advantages of electronic map:

Electronic map can easily combine the elements of ordinary map in any form to form a new map. Electronic maps can be drawn and output at any scale and in any range.

?

Baidu electronic map

Reference website: 1, common symbols on topographic maps:/link? URL = aluchzavpfrqirpt 5 ljtnwadlsfjdj 6 X5 xqurz 2 klc _ dq 3 197 s8q 8 dwvh 0 yh 1 plgpqdubnyg 4 ygluoqs 4 das 15n 7 cjvchkk 4 hog fii 2u

2. Map (Baidu Encyclopedia)/link? URL = a 4 yq 3 xx 6 mhwrhj w3 N2 keiflbrvxiu 82 lsymcea 1 yiddz 3 xdt xk 1 nyh 12 _ hjwkexvxv 9 wehuyut 7 opqk 4 hfe VJ 3 qtmiqnekac 3k 7 luk vigq

3. Electronic map:/link? URL = g7s _ 4d 3h 55 cpcc 2r pkkgrkqyduqvofhlefbioz-TJ 4 tuw wf 9 xft C5 _ rlqm 0-NLyFbjQR _ kbjnubhgwetwmqwq