Some standard content:
National Standard of the People's Republic of China
1 : 25 000 1: 50 000
Compilation specifications
for 1 : 25 000 1 : 50 000 topographic maps1Subject content and scope of application
GB 12343--90
This standard specifies the mathematical basis, accuracy, editing work, technical methods and comprehensive indicators of various elements of map content for compiling and drawing 1:25000 and 1:50000 national basic scale topographic maps. This standard is applicable to the compilation and drawing of 1:25000 and 1:50000 topographic maps by various departments of national economic construction. It can also be used as a reference for the compilation and drawing of geographic base maps for thematic maps.
2 Reference Standards
GB123421: 25000, 1:50000, 1:100000 topographic map patterns. 3 General Principles
3.1 Nature, Use and Basic Requirements of Topographic Maps3.1.11: 25000, 1:50000 topographic maps are national basic scale topographic maps. They are mainly used by various departments of national economic construction for survey, planning, design, scientific research, etc., and can also be used as basic data for compiling smaller scale topographic maps or thematic maps. 3.1.21: 25000, 1:50000 topographic maps should meet the following requirements: a. The symbols and annotations of topographic maps should be implemented in accordance with GB12342; b. The mean error of the plane position of the feature points on the map relative to the nearby field control points shall generally not be greater than ±0.5mm, and in special cases, it shall not be greater than ±0.75mm;
c. The representation and integration of each element should be able to reflect the geographical characteristics of the mapping area. The map content should be highly current, well-organized, and easy to read. The map lines should be fine, the specifications should be accurate, and the colors should be bright. 3.2 Mathematical basis, framing and numbering of topographic maps 3.2.1 Mathematical basis
The coordinate system adopts the 1980 Xi'an coordinate system, and the ellipsoid is the 1AG--75 ellipsoid. The projection adopts the Gauss-Kruger projection, which is divided into 6° zones. The elevation system adopts the 1985 National Elevation Datum. 3.2.2 Framing and numbering
3.2.2.1 The international 1:1 million map framing system is adopted. 1:25000 topographic maps are framed according to the longitude difference of 7'30\ and the latitude difference of 5°00\; 1:50000 topographic maps are framed according to the longitude difference of 15'00\ and the latitude difference of 10'00\. 3.2.2.21: The numbering of 25000 and 1:50000 topographic maps shall be in accordance with the provisions of Appendix B of GB12342-90 "1:25000, 1:50000, 1:100000 Topographic Map Format".
3.2.2.3 In addition to the map number, each map shall also be marked with a map name. The map name shall be the name of the main settlement within the map sheet. For maps without settlements, other geographical names or elevation point annotations may be used as map names (approved by the State Administration of Technical Supervision on June 4, 1990, 296
implemented on December 1, 1990). GB 12343—90
3.2.2.4 Combined and split-map outline maps
For maps located near the national border or dominated by the sea, when there are only a few territorial, land or sea elements in the map near the adjacent map and the map is not used to connect other maps, it can be merged into the adjacent map and drawn into a combined map. The area of the combined map should not exceed the double-sided map. The merged part still uses the longitude and latitude lines as the outline boundaries. The map number of the combined map is indicated in a composite form: the map number of the whole map is in front, and the map number of the merged map is in the back, separated by a comma in the middle. If the merged elements are only between the inner and outer map outlines, the inner map outline is broken and the adjacent map number is not indicated. 3.3 Basic contour interval
The basic contour interval varies according to the terrain type of the mapping area. The regulations are shown in the table below. Only one basic contour interval is used in a map.
Terrain type
Hills
Basic contour interval
1: 25 000
When the terrain is very flat or the map requires it, the basic contour interval can be selected from the values in brackets. 3.4 Printing colors of topographic maps
Black, brown, blue and green are used for printing. 4 Editing preparation
4.1 Collection, analysis and selection of mapping data4.1.1 Collection of mapping data
Data that meets the following requirements should be collected as basic data:4.1.1.1
The latest topographic map that is larger than the mapping scale and is actually measured or compiled; a.
b. The accuracy of the topographic map meets the requirements of 3.1.2 and b; c. The topographic map should be highly current.
1:50000
Generally, 1:25000 topographic maps should be based on 1:10000 topographic maps; 1:50000 topographic maps should be based on 1:25000 topographic maps or 1:10000 topographic maps. In special cases, topographic maps with the same scale as the map compilation can be collected as basic data for local areas of the map. 4.1.1.2 As a supplement or reference to the basic data, the following data should also be collected: a.
The latest surveyed or compiled relevant nautical charts; a.
Aerial photographs, photo sketches, photo plans, etc.: current thematic maps and text materials such as administrative divisions, water systems, transportation, and place names. d.
Analysis and evaluation of mapping datawwW.bzxz.Net
Data used for compiling and drawing 1:25000 and 1:50000 topographic maps should be evaluated briefly based on careful analysis. The content generally includes:
the surveying and mapping agency, mathematical basis, and mapping age of the data; the currentness of the data and the completeness of the content; the conformity of the classification and grading of each element in the data with this specification and the classification and grading of the diagram, and the conversion principle. Based on the above analysis and evaluation, determine the degree and method of using basic data, supplementary data, and reference data. 4.1.3 The collection of basic data should be completed before the compilation and drawing operation. The collection of current data such as administrative levels and political division changes of residential areas above the county level should generally be completed before the original printed map is sent to the factory. 4.2 Research on the mapping area and preparation of the regional editing design book. 4.2.1 Research on the Mapping Area
The research on the mapping area is based on basic data, combined with supplementary data and reference materials, to understand the geographical overview and basic characteristics of the mapping area as a whole. The main contents of the study are: a.
The distribution characteristics and density differences of settlements, the basic characteristics of settlement planes and administrative significance, etc.; the grade, traffic conditions, distribution characteristics and density differences of roads, and the distribution of road ancillary facilities; b.
The status of boundaries at all levels, especially whether there are any problems to be dealt with at national and provincial boundaries; c.
The structural characteristics and river network density of river systems, the types and distribution characteristics of lakes, and the distribution of artificial water systems such as canals, ditches, and reservoirs; d.
The types of coasts, the distribution characteristics of islands, reefs, and navigation facilities, and the morphological characteristics of submarine landforms; e.
The types and morphological characteristics of landforms;
The distribution characteristics of various vegetation;
The distribution of landforms with special cultural, historical or economic values; h
The distribution of other elements.
Through the above analysis and research, write a brief description of the geographical characteristics of the mapping area according to the needs of the compilation and mapping work. 4.2.2 Regional Editing Design Book
The regional editing design book is a technical document guiding the compilation and drawing of each map sheet in the mapping area. It is drafted by the responsible editor who undertakes the task and implemented after approval by the superior competent department. Its contents are: a.
Task overview (including the scope of the mapping area, the number of maps, the deadline and requirements for completing the task); a brief description of the geographical characteristics of the mapping area; b.
Evaluation and use instructions for mapping data;
Compilation and drawing technical methods: specific provisions on the processing of basic data and the production method of the original map, e. : The compilation and drawing of each element of the map content, focusing on the specific description of the selection of indicators, summarization methods, and the processing of the relationship between each element. Supplementary provisions should be made for special technical issues not covered in the specifications. f. Production of printed original map: specify the method of engraving or clear drawing of specific map sheets (or element plates), and put forward technical requirements for engraving (drawing) of each element:
: Attachments to the regional editing design book: generally include the map sheet connection table of the mapping area, basic data outline map, administrative division outline map, comprehensive sample map, new and old diagram symbol comparison table, copy and connect edge relationship map, etc. 5 Editing and drawing technical methods
5.1. Compilation and drawing methods and data processing
The following methods can generally be used to compile and draw the original map: a. Enlargement compilation method: On the basic data, enlarge the symbol specifications and comprehensive indicators according to the corresponding magnification of the map scale to compile the topographic map content, then reduce it to the map scale, and engrave (draw) in separate plates to obtain the printed original map. The annotation plate is compiled by cutting and pasting transparent annotations on a transparent film base. And it is used as the annotation plate of the printed original map b. Equal-size compilation method: Mark and trace the elements on the basic data that are not suitable for photography, then reduce it to the map scale, and compile it in one or two plates (line plate, annotation plate).
c. Combined compilation and engraving (drawing) method: Mark and trace the elements on the basic data that are not suitable for photography, or mark and compile according to the complexity of the topographic map content, then reduce it to the map scale, and compile and engrave (draw) in separate plates at one time. The topographic map content added or modified according to the supplementary data should generally be transferred to the basic data during the compilation. 5.2 Preparation of base map
5.2.1 Mathematical basis
GB 12343-90
Draw the rectangular coordinate grid points, map outline points and survey control points for every 1km on the mounting board (or film) at one time. For each map within 30'00\ of the western edge of each projection zone, 1:25000 map within 7'30\ of the eastern edge of each projection zone, and 1:50000 map within 15'00\, the adjacent zone coordinate grid should also be drawn. In order to ensure the accuracy of the mosaic of the map data, the control points used for mosaic base map in each map are generally 16 to 20, and they should be evenly distributed. It is preferred to use high-level survey control points as mosaic control points. When there are no survey control points or the number is insufficient, the intersection of the coordinate grid can be used. Point accuracy requirements:
Rectangular coordinate network tolerance: the error of each side length shall not exceed ±0.1mm, the error of the diagonal shall not exceed ±0.2mm, and the error of the adjacent zone coordinate network point shall not exceed ±0.1 mm.
Outline tolerance: the outline point error shall not exceed ±0.1mm, the outline side length error shall not exceed +0.15mm, and the diagonal error shall not exceed ±0.2mm.
Measurement control point tolerance: the point error shall not exceed ±0.1mm. 5.2.2
Collage of map data
The data used for collage should have clear graphics, solid lines, no background color, no yellow spots, and be easy to copy. The outline side length should be slightly smaller than the theoretical size, but generally should not be less than 0.4%~1% (except for film maps). The outline edge cutting error shall not be greater than 0.1mm. Collage accuracy requirements: point error does not exceed 0.1mm, overlap and crack does not exceed 0.2mm, straight line deformation loss does not exceed 0.2mm. When using a large version of collage that is twice the scale of the map, the error is allowed to be magnified by half. 5.3 Preparation before compilation, compilation sequence and color 5.3.1 Preparation before compilation
a. Check whether the mathematical accuracy of the compilation base map meets the requirements, whether the drawing quality is suitable for depiction, and whether the compilation data is complete. b. Draft a map compilation description and formulate a map operation plan. The map compilation description refers to the technical description of the compilation operation of a single map, which should be formulated in accordance with the provisions of the specifications and the regional editing design book, combined with the actual situation of the specific map. Its contents include: analysis of the content of the map, use of mapping data, selection indicators of each element, summary methods and relationship processing, etc.
Determine the degree of integration of each element at the edge of the map and the connection with the adjacent map. c
5.3.2 Compilation and drawing sequence
Generally, the following sequence should be followed:
map outline, rectangular coordinate grid lines;
plane control points, elevation points, industrial and mining buildings, public facilities and independent features; water systems and appurtenances;
railways, major residential areas:
highways and road appurtenances;
minor residential areas and general roads;
pipelines and fences;
landforms and soil quality;
boundaries;
vegetation;
map copying edges;
map outline decoration;
notes.
If the equal-size compilation and drawing method is adopted, the general coloring of water areas and color-coded vegetation should be carried out on the compilation and drawing base map first. For maps with many colored vegetation, a single colored vegetation plate made of polyester film can be made, and the colored vegetation range line can be drawn, and the map is not dyed. This plate can be used as a colored plate for printing the original map. If the method of splitting and engraving (drawing) is adopted, the water system plate should generally be engraved (drawn) first. Then the landform plate, landform plate, colored vegetation plate, and annotation plate should be engraved (drawn) in sequence. The plates should be checked for registration and the avoidance relationship should be handled properly. 299
5.3.3 Colors for compilation and drawing
GB12343-90
Use light blue to dye water areas, light purple to dye colored vegetation, green to draw water system symbols and lines, brown to draw landforms and texture, and black to draw other elements of map content.
5.4 Quality requirements for the compilation and drawing of original maps and filling in the map calendar 5.4.1 Quality requirements for the compilation and drawing of original maps
a. The mathematical accuracy should meet the requirements.
b. Use all kinds of mapping materials correctly and fully. C. The integration and representation of the various elements of the topographic map content shall comply with the provisions of Chapter 6 and the regional editing design book, and the relationship between the various elements shall be clear and reasonable.
The symbol specifications shall comply with the provisions of the diagram, the lines shall be solid, the colors shall be suitable for copying, and the map surface shall be clean. d.
All kinds of annotations shall be correct, the configuration shall be appropriate, and the instructions shall be clear. e.
f. The content outside the map outline shall be correct, complete, and the configuration shall comply with the regulations. g. The copying and joining edges of the map sheets shall be correct.
For the maps that are compiled and engraved (drawn), their quality shall also meet the quality requirements for printed original maps in Article 7.1.4. 5.4.2 Filling in the map calendar
The map calendar shall correctly reflect the compilation and drawing process of each topographic map. The map calendar shall record the mathematical basis of the compiled map sheet, the coordinates of the plane control points, the collage accuracy, the map sheet compilation and drawing instructions, the use of materials, the handling of major problems and the evaluation of the quality of the map. The calendar book should be filled in by the operator and the relevant editors and inspectors at each stage of the topographic map compilation. 6 Compilation of various elements of the topographic map
6.1 Survey control points
Survey control points should generally be indicated. When dense, buried stone points can be appropriately selected. For survey control points located in residential areas, if they affect the clarity of the residential areas, the leveling points may not be indicated, and other control points may only be indicated with symbols. No elevation is noted. Before drawing the survey control points, the coordinate values of the control point results table should be used to check the point positions. If the point position does not match the coordinate value and the error is more than 0.2mm (excluding 0.2), it should be abandoned or changed to elevation point representation: if the error is within 0.2mm, it should be corrected on the map, and the point position drawing tolerance is 0.Imm.
6.2 Industrial and mining buildings, public facilities and independent featuresa. Industrial and mining buildings, public facilities and independent features should generally be indicated, and the names of those with names should be noted. However, within the block-type residential area, only tall and prominent features with certain orientation functions or historical, cultural and economic significance (such as clock towers, towers, TV transmission towers, scientific observation stations, etc.) are generally indicated. For densely distributed smaller features (such as piles, pits, graves, etc. that are not based on scale), appropriate selection can be made on the 50000 map.
b. Industrial and mining buildings, public facilities and independent features with positioning points should be accurately depicted, and the error should not exceed 0.2mm. When overlapping with residential areas, water systems, roads and other features, the residential areas, water systems, and road edges can be interrupted to draw the symbols of the above features completely. ℃. When the features represented by scale on the mapping data are smaller than the size of the symbols not based on scale due to the reduction of scale, they should be represented by symbols not based on scale.
6.3 Water system and ancillary facilities
Correctly indicate the type, primary and secondary relationship, ancillary facilities and names of the water system; reflect the distribution pattern of water system elements and the density comparison of different regions; handle the relationship between the water system and other elements. 6.3.1 Shoreline
The shoreline includes the coastline, river shoreline, lake shoreline and the shoreline of other water system objects. When synthesizing the shoreline graphics, pay attention to keeping the correct position of the main turning points of the shoreline, the contrast of the degree of shoreline curvature and the contrast of water and land areas. The curvatures smaller than 0.5mm×0.6mm on the map can be appropriately simplified, and the characteristic curvatures should be exaggerated to 0.5mm×0.6mm. When the shoreline is close to the contour line, it must be coordinated with the contour line graphics. When the shoreline overlaps with the protection dike, the shoreline can be omitted. 300
6.3.2 Rivers, canals, ditches
6.3.2.1 Representation of rivers, canals, ditches GB 12343--90
Figure 1 Rivers with a width of more than 0.4 mm shall be represented by double lines according to the scale, and those with a width of less than 0.4 mm shall be represented by a single line. Streams represented by a single line shall be represented by a gradually changing line thickness of 0.1~0.4 mm depending on their length on the diagram. Canals and ditches with a width of more than 0.4 mm on the diagram shall be represented by double lines according to the scale, and those with a width of less than 0.4 mm shall be represented by a single line, and shall be represented by a line thickness of 0.3 mm and 0.15 mm respectively depending on their primary and secondary. 6.3.2.2 Selection and integration of rivers, canals and ditches Rivers, canals and ditches should generally be indicated. In areas with dense river networks, rivers and ditches with a length of less than 1 cm on the map can be discarded as appropriate. However, the rivers and ditches that constitute the network system should be selected based on the characteristics of the river and canal network plan. The spacing between dense rivers and canals should generally not be less than 3mm. The spacing between cross-flows in the floodplain area of the old riverbed and areas with dense ditches should not be less than 2mm. Disappearing river sections with a length of more than 2mm, underground river sections with a length of more than 1mm, and seasonal rivers with a length of more than 1.5cm on the map should be indicated. Seasonal rivers that are the source of rivers should be indicated as perennial rivers when their length is less than 5mm. Dry ditches with a length of more than 1.5cm on the map should be indicated. When selecting rivers, canals and ditches, they should be selected in order from large to small, from primary to secondary. Boundary rivers, single-flow rivers, and small rivers connecting lakes and water-deficient areas in deserts must be selected.
Rivers, canals and ditches must indicate the flow direction. Navigable river sections must indicate the flow rate. Longer rivers and canals are generally marked every 15 to 20 cm. When the distance between the high water boundary and the water beach line is greater than 2 mm on the map, it should be indicated. When most of the distances are greater than 2 mm and only part of them are less than 2 mm, the high water boundary should be regarded as a continuous whole and indicated in its entirety. The section between the high water boundary and the water edge line should be filled with the corresponding soil and vegetation symbols. When the high water boundary coincides with a steep bank or embankment, the high water boundary is omitted; when it coincides with a contour line, the contour line is omitted. 6.3.2.3 The names of rivers, canals, and ditches should generally be noted. For longer rivers and canals, the names should be repeated every 15 to 20 cm. The notes should maintain a certain level difference according to the relationship between the upstream and downstream of the river and the main and tributary relationships. When there are many river names, the names of minor small rivers can be omitted. Seasonal rivers (lakes) must be annotated with the months with water. If the months with water are the same in a map, a note can be added outside the map, but no note is made in the map. 6.3.3 Lakes and reservoirs
Lakes and reservoirs with an area larger than 1mm on the map should be indicated. Small lakes with an area smaller than this but of great significance (such as small lakes near national borders, small lakes that serve as river sources, and freshwater lakes in water-deficient areas) should be exaggerated to 1mm". When lakes are densely clustered, their distribution range and characteristics should be maintained, and some lakes with an area smaller than 1mm2 should be appropriately selected, but they cannot be merged. Lakes and reservoirs should generally be named, and clustered lakes can choose their main names. The name annotation should maintain a certain level of difference according to the size of the lake or reservoir area or the size of the reservoir capacity. Non-freshwater lakes must be annotated with water quality.
The capacity is 1,000 cubic meters The above reservoirs and important small reservoirs must be filled with storage capacity. 6.3.4 Wells, springs, karez, and reservoirs
Wells, springs, karez, and reservoirs in water-scarce areas should be indicated, and appropriate selections should be made in other areas. Wells that are not drinkable must be filled with the nature of the water. The main wells can be optionally noted with the depth from the mouth to the water surface and the ground elevation. White flow wells, hot spring wells, mineral springs, hot springs, geysers, poisonous springs, etc. should be annotated with descriptions of their properties.
Geothermal wells and geothermal pools should be indicated.
Wells and springs with proprietary names should be named in sparsely populated areas, and selected in other areas. 6.3.5 Swamps and salt pans
a. Swamps with an area greater than 25mm2 on the map should be indicated, and saline-alkali swamps should be annotated. Narrow swamps distributed along rivers, 1 cm or more should be selected.
b. Salt pans with an area larger than 2mm2 on the map should be indicated. Salt pans with an area of 2~4mm2 are indicated with non-scale symbols, and salt pans larger than 4mm2 are indicated with scale. For salt pans indicated with scale, the grid lines of each part inside must reflect the actual density and planning characteristics. Salt pans with proprietary names should be named. 6.3.6 Islands, reefs, and beaches
6.3.6.1 Islands
Islands (sandbanks) with an area larger than 0.5mm2 on GB12343-9D
maps should be indicated. When depicting islands, care should be taken to maintain their accurate location and basic outline shape. When islands are too dense to be represented one by one, they can be represented while maintaining their exterior. Selection shall be made on the basis of the edge contour and density comparison, but shall not be merged. Isolated, famous or small islands located on both sides of the national border should generally not be discarded, and can be exaggerated to 0.5mm2. Named islands (sandbanks) should be named. When densely packed, individual minor islands can be omitted, but islands located on both sides of the national border should be named as much as possible.
6.3.6.2 Reefs
Open reefs, hidden reefs and dry reefs should all be represented, and they can be appropriately selected when densely packed. Reefs represented according to scale should be explained and annotated. Reefs that cannot be represented according to scale after the scale is reduced can be represented by corresponding non-scale symbols. Named reefs should be named.
6.3.6.3 Dry beaches, underwater beaches, and aquaculture farmsa. Dry beaches with an area greater than 4mm2 on the map should be represented, and dry beaches with an area less than 4mm can be appropriately merged into larger beaches within 2mm of each other, and the types can be ignored. Isolated beaches with an area less than 4 mm2 can be expanded or discarded according to the situation. Small-area beaches distributed in patches can be selected or discarded. Dry beaches with a width narrower than 1 mm are represented by narrow dry beach symbols. River channels and tidal ditches within dry beaches can be selected or discarded when they are dense. Double-row dotted river channels and tidal ditches with a width of less than 0.4 mm on the map can be changed to single-row dotted lines, and attention should be paid to the coordination with the connected rivers represented by single or double lines. b. Submerged beaches (shallow beaches) and sandy beaches with an area greater than 4 mm2 on the map should be represented, and those with an area smaller than this or a width narrower than 2 mm can be discarded. When dense, those with an interval of less than 2 mm can be appropriately combined and represented. c. Aquaculture farms should be represented and the product name should be noted. 6.3.7 Steep banks, bank ridges, dangerous banks, waterfalls, and rocky beaches a. Steep banks with a length of 5 mm and a relative height of more than 2 m on the map should be represented and the relative height should be noted. If the symbol of a steep bank without a beach cannot be drawn in a river represented by two lines, it can be moved to the outside of the shoreline and drawn close to the shoreline. A river represented by a single line does not represent a steep bank without a beach. A distance of 0.2 mm must be maintained between a steep bank with a beach and the shoreline on the map. If the distance is less than this, the steep bank symbol can be slightly moved; if the distance is greater than 1 mm, the corresponding soil symbol should be filled in between. b. Bank barriers with a length of 5 mm and a specific height of more than 1.5 m should be represented on the map. When the width is less than 1 mm, it is represented by a single row of short lines; when the width is more than 1 mm, it is represented by a double row of short lines.
c. Dangerous banks with an area of more than 25 mm on the map should be represented. d. Waterfalls, waterfalls, and rocky beaches should be represented in rivers represented by two lines and in major rivers represented by a single line. They can be selected in other river sections. The specific height of waterfalls should be added. The names of famous waterfalls must be noted. 6.3.8 Isobaths, water depth notes, tidal directions, and ocean names notesa. Indicates the depths of 2, 5, 10, 20, 30, 50, 100, 200m. The depth annotations are usually arranged in groups, with the letterhead pointing to the shallow water. Slope lines should be drawn at places where the slope direction is difficult to read and at the lowest closed depth line. When the spacing between depth lines in steep slopes is less than 0.2mm, individual depth lines can be interrupted. b. The density of water depth annotations is based on the principle of dense shallow water and sparse deep water, and is determined according to the seabed topography. The number of selections per 4cm2 on the map is generally: 4 for water depths within 5m, 2~3 for water depths between 5~10m, and 1 for water depths greater than 10m. Water depth annotations around shoals, estuaries, islands, reefs on both sides of the channel and where the terrain changes sharply should be selected first, and can be slightly denser than the above indicators. Water depth annotations are accurate to whole meters. Indicates the direction of tidal rivers and seawater currents.
Oceans, straits, bays, estuaries, trenches, troughs, capes, etc. must be marked with their names, and the size of the markings should maintain a certain level difference. d.
6.3.9 Auxiliary facilities of water systems
Embankments: earthen embankments and stone embankments with a length of 5 mm and a specific height of more than 1.5 m on the map should be indicated. Embankments with a specific height of more than 5 m or important flood and tide control functions shall be indicated with the main embankment symbol and the embankment top elevation shall be added; those with a specific height of less than 5 m shall be indicated with the general embankment symbol. b. Embankments: embankments with a length of 5 mm and a specific height of more than 1.5 m on the map shall be indicated, and those with a specific height of more than 2 m shall be indicated with the specific height. 302
GB12343—90
℃. Sluices, rolling dams, and water check dams: they shall be indicated on rivers indicated by double lines and main rivers indicated by single lines, and shall be indicated on other rivers as needed.
d. Reinforced banks: those longer than 2mm on the map should be indicated. Reinforced banks in rivers represented by single lines and rivers represented by double lines narrower than 0.7mm on the map are not indicated.
e. Piers, moorings, dry docks, breakwaters, and dams: one of the buildings in a river represented by double lines should be indicated. When the width of the river is narrow and difficult to depict, the symbol size can be reduced or omitted. f. Water channels and channel heads: - generally should be indicated. Ferry crossings and fords: Ferry crossings and fords connected to roads should be indicated, and others can be omitted. g
h. Navigation aids: generally should be indicated. Lighthouses must indicate the height of the lights. i. Hydrological stations: - generally should be indicated, and corresponding explanations and notes should be added. 6.4 Settlements
Correctly indicate the location, outline, basic structure, traffic conditions, administrative significance and name of the settlements, reflecting the type and distribution characteristics of the settlements and the relationship between the settlements and other elements. 6.4.1 Selection of residential areas
Residential areas are basically all represented. In densely populated areas, individual small residential areas can be appropriately abandoned, but residential areas located at road intersections, river junctions, mountains, ferries, commanding heights, national borders, important mineral resources, cultural relics and historical sites, etc. should be represented in detail. 6.4.2 Representation of residential areas
6.4.2.1 Block-type residential areas
When synthesizing blocks, attention should be paid to maintaining the overall structural characteristics of the block graphics (such as rectangles, trapezoids, irregular shapes), the comparison of housing density and the size comparison of block units (referring to the block blocks divided by streets on the map), and correctly displaying the traffic conditions inside the block. The unit area of the block in the densely populated urban area is generally 16-50mm2 on the 1:25000 map and 8-25mm2 on the 1:50000 map. The unit area of the block in the sparsely populated areas outside the city and the block-type rural residential areas is generally 4~16mm2 on the 1:25000 map and 2~8mm2 on the 1:50000 map. For houses distributed in rows and columns, the positions of the two ends should be fixed, and the house symbols should be inserted in the middle, and they should not be merged into blocks. Ordinary houses on the outer edge of the block shall not be merged into the block, and appropriate selection should be made. The passages in the block are usually divided into primary and secondary according to their traffic conditions, road width, economic significance and other factors. Streets in the city are generally represented by scale if the width is greater than 0.5mm on the map, and the main street symbol is used for those between 0.3~0.5mm, and the secondary street symbol is used for those less than 0.3mm. The main street must be named. For towns and block-type rural residential areas, all streets connected to the highway are represented as main streets, and the rest are represented as secondary streets. The outer contour of the residential area should be clearly reflected, and the convex and concave corners of the block less than 0.5~1mm on the map can be integrated. When the open space area in the block is larger than 2-8mm2 on the map, it should generally be indicated. Green planting areas larger than 10mm should also be filled with corresponding vegetation symbols. 6.4.2.2 Hash-type residential areas
Pay attention to maintaining the range, shape and house density comparison of the residential distribution area. Give priority to selecting houses that are in scale and located in the center and peripheral features of the residential area. For residential areas distributed in strips along roads and rivers, houses at both ends should generally be selected first, and the middle should be appropriately selected according to their density.
6.4.2.3 Dispersed residential areas
Should correctly reflect the general distribution range of the residential area, house distribution characteristics and density comparison. For residential areas whose range can be clearly determined based on terrain and names, they should be appropriately emphasized.
6.4.2.4 Cave-type residential areas
Pay attention to maintaining the approximate distribution range and central position of their residential areas. When cave dwellings distributed in rows cannot be represented one by one, the positions of the cave dwellings at both ends should be kept accurate, and the middle layers should be interpolated, and the different situations of continuous and discontinuous arrangement should be reflected. For cave dwellings distributed in multiple layers, the positions of the upper and lower layers should be kept accurate, and the middle layers should be interpolated. For settlements composed of cave dwellings and houses, the density contrast of cave dwelling and house symbols should be maintained. The dense cave symbols should be arranged along the slope wall direction and coordinated with the contour lines. 6.4.2.5 Mongolian yurts and sheds
GB 12343—90
Yurts, pastoral tents and sheds represented according to scale should generally be represented. If there is a name, add the name, and seasonal ones must indicate the month of residence. Sheds not according to scale are only represented when they are in areas with fewer features and have a directional function. 6.4.3 Name annotation of settlements
All selected settlements should generally be annotated with names. Settlements above the town level should be annotated according to the full administrative name. When the administrative name is inconsistent with the natural name of the place of residence, the natural name of the place of residence is noted as the secondary name. The secondary name is two levels lower than the main name, and is generally noted below or to the right of the main name in brackets. Township-level settlements are noted according to the administrative name, and the word "township" is omitted. When a settlement is the seat of more than two governments, only the higher-level name is noted. State-owned agricultural, forestry, animal husbandry, and fishery farms should be noted in full, and the word "state-owned" can be omitted. Villages are noted according to natural names. Factories, schools, cemeteries and other units are noted with proper names.
The settlement where the township and town governments are located must be noted with the number of people in the administrative area. The population number is noted below the name of the settlement, and a legend is given. \When the township and town governments are located in the same settlement and only one of the names is noted on the map, only the population number in the administrative area is noted. The population number is not noted for administrative areas above the county level (including the county level).
The names of settlements should be properly arranged and clearly indicated, and avoid covering the population, road intersections and other important features of the settlements. When the names of dispersed settlements are not clearly indicated, they should be annotated according to the distribution of house symbols and the location of the name annotations on the data. When a settlement has a general name and a sub-name, the general name and part of the sub-names should generally be selected first; when the general name is still unclear, the sub-names can also be retained and the general name can be discarded.
When the settlement name is crowned with above, below, east, west, south, north, front, back, big, small, etc., it is generally not possible to handle it according to the general name and sub-name. When it is dense, the name of the larger village should be selected.
When the settlement annotations are dense, the names of ordinary houses or individual smaller settlements can be appropriately omitted. 6.5 Roads and ancillary facilities
Correctly indicate the category, grade, and location of the road, reflecting the structural characteristics of the road network, traffic conditions, distribution density, and relationship with other elements.
6.5.1 Selection and Representation of Roads
a. Double-track railways, single-track railways and railways under construction should all be represented. Branch railways leading to industrial and mining areas and factories and those shorter than 1 cm may be discarded as appropriate. When branch lines are too dense to be represented, only the main lines may be selected for representation. When a double-track railway is divided into two single-track railways and can be represented separately according to the scale, they are represented by the symbols of the two single-track railways respectively; if they cannot be represented separately, the straighter one should be selected and represented by the symbol of the double-track railway.
Electrified railways should be explained and annotated. If the section is very long, it can be repeated every 15 to 20 cm. Narrow-gauge railways and narrow-gauge railways under construction should be represented. Light railways should be explained and annotated. b. Expressways, grade roads, sub-grade roads and all levels of roads under construction should all be represented. The technical grade code of the road must be annotated, repeated every 15 to 20 cm, and it is not necessary to annotate if the length is less than 5 cm. ℃. Mechanized farming roads should generally be indicated. Rural roads and small roads on 1:50000 topographic maps and small roads on 1:25000 topographic maps can be appropriately included.
When selecting roads, it should be done from important to secondary, from high to low, and pay attention to maintaining the density difference of the road network. The road grid size is generally 2-4cm2, and the densest should not be less than 1cm\. Priority should be given to roads connecting townships, towns, and large villages, roads leading to high-level roads, stations, docks, and mines, roads as administrative boundaries, roads crossing national borders, and roads connecting water sources. Generally, there should be roads connecting settlements and between settlements and major landforms. When there are several roads connecting two settlements, roads with higher grades and shorter distances should be given priority.
d. Seasonal roads and unfixed roads should be indicated in areas with underdeveloped transportation, and can be selected when dense. Seasonal roads should indicate the months of traffic. e. Fixed overhead ropeways should be indicated.
6.5.2 Graphical summary of roads
GB 12343-90
Railways and highways are generally not simplified. For zigzag bends on mountain roads, if it is difficult to depict double lines, common edge depiction or reduced symbol width can be used; when there are multiple zigzag bends in parallel and it is impossible to represent them one by one on the map, they should be appropriately simplified while maintaining the accurate positions of both ends and the zigzag features.
Machine-farmed roads, rural roads and small roads can be appropriately summarized, and some small bends without characteristic significance should be discarded. The road intersections represented by dotted lines should be connected with the real part, and when changing levels, the ground feature points should be used as the change points. 6.5.3 Road ancillary facilities
a. Stations and ancillary buildings
Railway stations and pass stations should be fully represented. Station symbols are drawn at the main platform entrances and exits, and the black blocks in the symbols are drawn on the side of the station building. Other symbols covered by station symbols can be shifted or omitted. When the station lines in the station cannot be represented one by one, the outer station lines are accurately drawn, and the middle station lines are evenly arranged, but the spacing should not be less than 0.3mm. The overpasses in the station, when the map.When the length is less than 3 mm, it may not be indicated. The station name should be indicated, but when the station name is the same as the name of the residential area and is very close to it, the station name may not be indicated. Locomotive turntables, car stops, and signal lights and columns with directional significance should be indicated. b. Road ancillary buildings
Tunnels longer than 1 mm on the map should be indicated, and those shorter than 1 mm can be appropriately selected. Culverts on railways and highways should be indicated.
Embankments and cuttings with a length of 5 mm and a relative height of more than 2 m on the map should be indicated, and the relative height should be noted. c. Bridges
Bridges on railways and highways should be indicated, and bridges on other roads should be indicated briefly. Bridges on highways must be indicated with load capacity. Important bridges should be named. Flood bridges, cable bridges, etc. should be annotated with explanations, and seasonal bridges should be indicated with the month of passage. d. Road signs and milestones
Road signs with directional functions on the road should be indicated. In areas where there are no directional objects, the milestones on the road should be indicated and the kilometers should be noted.
6.5.4 Road accessibility notes
The accessibility and mileage of railways, highways and main roads in sparsely populated areas should be noted at the exit of the map. Railways should indicate the destination station ahead; highways or other roads should indicate the accessibility to the township or town-level or above residential areas on the adjacent map. If there are no township or town-level or above residential areas on the adjacent map, larger residential areas can be selected for quantity annotation. When there are many roads, only the accessibility notes of the trunk lines or main roads can be noted. When a railway or highway passes between the inner and outer map outlines and then enters the main map sheet, the road graphics should be drawn continuously between the map outlines without the accessibility notes. 6.6 Landform and Soil Quality
Correctly record the basic landform types and morphological characteristics of each region, maintain the correct position and elevation of landform feature points and geomorphic lines, reflect the degree of ground cutting and soil type and distribution law, and handle the relationship between landform and other elements. 6.6.1 Contour Lines
Based on the terrain characteristics and data conditions of the mapping area, select the basic contour interval according to Article 3.3. Contour lines with elevations 5n times the contour interval (n is a positive integer, the same below) are represented as counting curves. When 2.5m is used as the basic contour interval, contour lines with contour intervals 4n times are represented as counting curves. In areas where the basic contour interval cannot reflect the characteristic terrain undulations and micro-geomorphological morphology, such as plains, plateaus, basins, gentle mountain tops, saddles, depressions, river terraces, floodplains, etc., half-interval contour lines or even auxiliary contour lines should be drawn. 6.6.2 Integration of contour graphics
6.6.2.1 When integrating contour graphics, the morphological characteristics of ridges, hilltops, valleys, slopes and saddles should be correctly expressed according to the characteristics of different regional landform types. In general, minor negative landform fragments are deleted, but when summarizing the graphics of blade ridges, horn peaks, cirques, depressions, square mountains, etc., minor positive landform fragments can be deleted. In order to emphasize the landform characteristics, individual contour lines can be appropriately shifted locally (the maximum should not exceed half of the contour interval), but care should be taken to avoid contradictions between contour lines and nearby control points and elevation points. The distance between two adjacent contour lines should not be less than 0.2mm. If it is insufficient, individual contour lines can be interrupted, but they must not be disconnected in groups. 6.6.2.2 Integration of basic landforms
GB12343-90
a. Ridge: Correctly express the shape of the ridge, the extension direction and the relationship between the main ridge and the branch ridges. The spacing of contour lines at the top of the ridge shall not be less than 0.3mm. The contour lines of the narrow ridge can be closed in a pointed shape, and the contour lines shall not be shifted downhill in general; the contour lines on the upper part of the round ridge can be slightly shifted downhill to appropriately expand the ridge part. b Hilltop: Pay attention to reflecting the shape of small hilltops. The minimum diameter of the closed contour line of the hilltop is generally not less than 0.5mm, and small hilltops with boundaries can be appropriately enlarged. For small hilltops with elevation annotations, if the contour line cannot be drawn, one contour line can be omitted. Small hilltops with the same direction on the ridge can be appropriately merged when the distance is less than 0.3mm. In areas where small hilltops are clustered, they are generally selected but not merged. When selecting, attention should be paid to reflecting their distribution density and arrangement characteristics. Independent highlands located near major transportation routes, rivers, wide valleys, flat land and important landforms, as well as small hilltops with national surveying signs, boundary markers, etc., should be given priority.
C. Valley: Correctly indicate the size, shape and relationship between the main and branch valleys. The distance between the valley mouths of adjacent valleys on the map is generally 4~8mm for mid-mountain and high mountain landforms, 3~6mm for hilly and low mountain landforms, and 2~4mm for loess and aeolian landforms. When selecting valleys, the principle of selecting valleys should be followed from large to small, from primary to secondary. The main saddles and valleys through which roads pass should be selected first. d. Slopes: Pay attention to reflecting the characteristics of equal slopes, concave slopes, convex slopes, stepped slopes, steep slopes, triangular surfaces eroded by ice, weathered rock slopes, and fan-shaped slopes eroded by running water. e. Saddles: Pay attention to reflecting the symmetry and asymmetry of the saddles. The distance between the highest two corresponding contour lines on both sides of the saddle should generally not be less than 0.3mm. In areas with complex terrain and many saddles, some small and secondary saddles can be discarded, and emphasis should be placed on saddles through which roads pass and saddles that can show watershed characteristics.
f. Depressions: Depressions with an area larger than 1mm2 on the map should be selected, and depressions with an area smaller than this area can be selected as the larger one. When depressions are clustered, the depressions that can reflect their distribution characteristics should be selected.
The edge and bottom contour lines of the depressions should be plotted with slope lines, and independent hills, places where the slope direction is difficult to read, and hills and valleys on the edge of the map should also be plotted with slope lines.
6.6.3 Use of geomorphic symbols
a. Dry riverbeds and dry dripping lakes: Dry riverbeds with a length of more than 1.5cm and dry dripping lakes with an area of more than 2mm2 on the map should be indicated. Dry riverbeds with a width of less than 0.4mm on the map should be indicated with a single line, and dry riverbeds with a width of more than 0.4mm should be indicated with double lines. Dry cave lakes and dry riverbeds with a width of more than 1mm on the map should be filled with corresponding soil symbols. In areas with sparse landforms, names should be added if they have names. b. Gullies: Gullies longer than 6mm on the map should be indicated. When the width is less than 0.4mm, they should be indicated with a single line; when it is greater than 0.4mm, they should be indicated with double lines according to the scale. When it exceeds 2mm, the gully wall should be indicated with a steep virtual symbol; when it exceeds 3mm, contour lines should be added to its bottom. The distance between gullies should generally not be less than 2mm. When dense, gullies indicated by double lines should be preferred. c. Steep cliffs: Steep cliffs with a length of 5mm and a relative height of more than 2m on the map should be indicated. If there is a relative height, the relative height should be noted. Continuously distributed short cliffs with a distance less than 0.3mm can be appropriately combined for indication. d. Karst pits and rock peaks: Generally, they should be selected for indication. For the solution pit (enclosed land) represented by contour lines, when its area is less than 1mm", the solution pit symbol can be used instead and it should be selected first.
e. Terrace ridge: Terrace ridges with a length of 5mm and a specific height of more than 2m on the map should be represented, and the specific height should be noted. When the terrace ridge symbols are dense, the upper and lower layers of the terrace distribution area are drawn according to the actual location, and the other layers are appropriately selected. f. Rock wall: The length of more than 5mm on the map should be represented, and the specific height should be noted. g. Rocky land and steep rocky mountain l: Rocky land distributed in pieces, all symbols are configured within the range; small pieces of independently distributed rocky land. Symbols are generally configured at the original data position. The length of 5 on the map should be indicated, and the specific height should be noted. mm, steep rocky mountains with a width of more than 2mm should be indicated. When the size is smaller than this, contour lines can be used instead.
Mountain passes, caves, karst caves, landslides, landslides, mud-rock flows, and craters: Mountain passes, caves, and karst caves should generally be indicated, and the names should be added if they have names. h.
Mountain passes should be noted with elevations, and seasonal passes should be noted with the month of passage. Landslides and landslides with an area larger than 25mm on the map should be indicated. Mud-rock flows and craters - generally should be selected.
i. Granular snow fields, ice cliffs, ice cracks, ice and ice towers: Granular snow fields with an area larger than 10mm on the map should be indicated, and scattered distribution areas are insufficient 10mm can be appropriately exaggerated. Snowfields can be merged when the interval between grains is less than 1mm. The non-ice and snow area in the snow mountain should be indicated if it is larger than 10mm, and it can be merged into the snow mountain if it is smaller than 10mm. Ice cliffs, ice cracks, ice bumps, and ice towers should be indicated. 6.6.4 Sandy landforms, stone land, saline-alkali land, gravel land, small grass hill land, residual hill land, cracked land, etc. with an area larger than 1cm2 on the map should be indicated by corresponding symbols. All types of sandy land (except flat sandy land) with an area larger than 10cm2 should be annotated with the corresponding type name. 6.6.5 Elevation points and elevation annotations
Elevation points should be selected according to landform characteristics. More elevation points should be selected in areas with relatively fragmented and complex landforms, and fewer elevation points can be selected in relatively complete and simple areas. Generally, 10 to 20 elevation points are selected for every 100 cm2 in plain and hilly areas, and 8 to 15 elevation points are selected for every 100 cm2 in mountainous areas. Priority should be given to survey control points, water level points, the highest point in the map, the lowest point in a depression, the highest point in the region, the confluence of rivers, the intersection of roads, and the elevation points of named peaks and mountain passes.
For contour annotations, 5 to 10 elevation points should be selected for every 100 cm, with the words facing the height. 6.6.6 Geographical Names
a. The names of peaks, mountain tops, highlands, mountain passes, etc. must be noted, and they are generally noted in two levels according to the size of the mountain and its fame. b. The names of mountains and mountain ranges are determined by referring to other relevant map data, and the names of mountains and mountain ranges with obvious ridge directions are emphasized. The noted positions are arranged along the ridge direction. The size of the notes should maintain a certain level difference. ℃. The names of upland, grassland, sandy land, desert, gorge, valley, glacier, etc. are noted according to their scope and direction, and a certain level difference is maintained. 6.7 Pipelines and fences
The actual location of pipelines and fences should be correctly indicated to reflect the characteristics of the direction. 6.7.1 High-voltage wires: 5 cm long and 35,000 volts or more on the map should be indicated. High-voltage wires leading to residential areas are drawn to the edge of the residential area. High-voltage wires within 3 mm from railways and roads are not indicated, but at their bifurcations and turns, a section of high-voltage wire symbols should be drawn to indicate the direction. 6.7.2 Communication lines: except for areas with sparse features, other areas are generally not shown. Communication lines within 3mm of the railway or highway are not shown on the map, but a section of the communication line symbol should be drawn at its bifurcation and turning point to indicate the direction. 6.7.3 Pipelines: Pipelines longer than 2cm should be shown on the map, and corresponding explanations should be added. Only the entrances and exits of underground pipelines are shown. 6.7.4 Brick and stone walls, the Great Wall: Generally, they should be shown, and the height should be noted. 6.7.5 Earthen walls and fences: They should be shown if they are longer than 3mm on the map. When the fence at the edge of the residential area is shorter than 3mm but must be shown, it can be shown with a thin solid line instead. When the fence coincides with the street line, only the street line should be drawn. 6.7.6 Fences, barbed wire, and fences: They should be shown if they are longer than 1cm and have a height of more than 1.5m on the map. When the symbol coincides with the street line, only the street line should be drawn. 6.8 Boundary
Correctly reflect the level, position and relationship of the boundary with other elements. 6.8.1 National Boundary
6.8.1.1 The national boundary line should be accurately drawn according to the boundary treaty (protocol) and its attached map signed by the state. If the signed boundary treaty (protocol) has been jointly inspected and the original protocol and attached map have been amended, the national boundary should be drawn according to the relevant documents or attached maps of the joint inspection. The national boundary for which a boundary treaty (protocol) has not yet been signed should be drawn according to the traditional customary line. 6.8.1.2 The national boundary should be accurately drawn. In general, it should not be combined if it can be clearly expressed. The turning points and intersections of the national boundary should be depicted with the dot part or solid line segment of the national boundary symbol.
Boundary markers (boundary stakes, boundary monuments) on the national boundary should be accurately drawn and their numbers should be indicated. When two or three boundary markers with the same number cannot be drawn at the same time, hollow small circles should be drawn according to the relative relationship on the ground and their respective numbers should be indicated. Settlements, roads, mountains, mountain passes, rivers, islands and sandbanks located on or close to the national boundary line should be indicated in detail, and their territorial relationship should be clearly stated.
The names mentioned in the boundary treaty should be indicated as far as possible according to the appendix to the treaty. The annotations shall not cover the national boundary symbols. 6.8.1.3 The national boundary symbols on land must be drawn continuously. The national boundary bounded by rivers and linear features can be indicated in the following two ways: a. For the national boundary bounded by the center line of the river or the main channel line, when the river is represented by double lines and the national boundary symbol can be drawn in between, the national boundary symbol should be drawn continuously and the ownership of the islands should be correctly indicated; when the national boundary symbol cannot be drawn within the river symbol, the national boundary symbol should be drawn alternately on both sides of the river without interruption, and the ownership of the islands and continents should be indicated in brackets with explanatory notes (with a brief note of the country name). b. When the boundary is a shared river, the national boundary symbols are drawn alternately every 3 to 5 cm on both sides of the river, and the ownership of the islands and continents should be indicated in brackets with explanatory notes 307
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