Circular No. 19/2019/TT-BTNMT on technical regulations for the content and symbols of national topographic maps at scales of 1:2,000 and 1:5,000.

Technical regulations on the content and symbols of national topographic maps at scales of 1:2,000 and 1:5,000.

Pursuant to the Law on Surveying and Mapping dated June 14, 2018;

Pursuant to Decree No. 27/2019/NĐ-CP dated March 13, 2019 of the Government detailing certain provisions of the Law on Surveying and Mapping;

On the basis of Decision No. 36/2017/NĐ-CP dated April 4, 2017, of the Government stipulating the functions, tasks, powers, and organizational structure of the Ministry of Natural Resources and Environment;

The Minister of Natural Resources and Environment promulgates this Circular on technical regulations on the structure model and content of the national geographic base database at scales of 1:10,000 and 1:25,000.

The Minister of Natural Resources and Environment issues the Circular stipulating technical regulations on the content and symbols of national topographic maps at scales of 1:2,000 and 1:5,000.

PART I

GENERAL PROVISIONS

Article 1. Scope of Regulation

This Circular specifies the content and symbols of national topographic maps at scales of 1:2,000 and 1:5,000.

Article 2. Applicability

This Circular applies to agencies, organizations, and individuals related to the establishment, storage, management, and provision of national topographic maps at scales of 1:2,000 and 1:5,000.

Article 3. Explanation of Terms

In this Circular, the following terms shall be understood as follows:

1. National topographic maps at scales of 1:2,000 and 1:5,000 are maps representing terrain features, geographic objects, borders, administrative boundaries, and place names on land, islands, and archipelagos constructed according to national technical standards and norms at scales of 1:2,000 and 1:5,000 within the national coordinate system and national elevation system for uniform use throughout the country.

2. Proportional symbols are symbols whose size is proportional to the actual size of the geographic object.

3. Half-proportional symbols are symbols with one dimension proportional to the actual size of the geographic object, while the other dimension represents a convention.

4. Non-proportional symbols are geometric representations of geographic objects with conventional sizes that do not follow the actual size of the geographic object.

5. National coordinate points are national survey points with spatial coordinate values established according to national technical standards and norms.

6. National elevation points are national survey points with elevation values established according to national technical standards and norms.

7. National coordinate and elevation points are national survey points with spatial coordinate values and elevation values established according to national technical standards and norms.

8. National gravity points are national survey points with gravitational acceleration values established according to national technical standards and norms.

Article 4. Mathematical Basis

1. National topographic maps at scales of 1:2,000 and 1:5,000 are established within the national reference system and coordinate system VN-2000, and the national elevation system.

2. National topographic maps at scales of 1:2,000 and 1:5,000 are established within the transverse cylindrical equal-angle projection with the central meridian at 3º and a scale factor k0 = 0.9999.

3. The zone number, central meridian, and zone boundary meridians are as shown in Table 1 below:

Table 1

4. Division and designation of national topographic map sheets at scales of 1:2,000 and 1:5,000 are specified in Circular No. 973/2001/TT-TCĐC dated June 20, 2001, of the General Department of Land Administration (now the Ministry of Natural Resources and Environment) "Guidelines for Applying the National Reference System and Coordinate System VN-2000" as follows:

a) Division and designation of national topographic map sheets at scale 1:5,000 Each national topographic map sheet at scale 1:100,000 is divided into 256 national topographic map sheets at scale 1:5,000, each sheet having dimensions of 1'52.5" x 1'52.5", designated by numbers from 1 to 256 in sequence from left to right and top to bottom.

The designation of a national topographic map sheet at scale 1:5,000 consists of the designation of the national topographic map sheet at scale 1:100,000 containing that map sheet, a hyphen, and then the designation of the national topographic map sheet at scale 1:5,000 within the national topographic map sheet at scale 1:100,000 enclosed in parentheses.

For example, a national topographic map sheet at scale 1:5,000 has the designation F-48-68-(256).

b) Division and designation of national topographic map sheets at scale 1:2,000

Each national topographic map sheet at scale 1:5,000 is divided into 9 national topographic map sheets at scale 1:2,000, each sheet having dimensions of 37.5" x 37.5", designated by Latin letters a, b, c, d, e, f, g, h, k (excluding i and j to avoid confusion with 1) in sequence from left to right and top to bottom.

The designation of a national topographic map sheet at scale 1:2,000 consists of the designation of the national topographic map sheet at scale 1:5,000 containing that map sheet, a hyphen, and then the designation of the national topographic map sheet at scale 1:2,000 within the national topographic map sheet at scale 1:5,000, enclosed in parentheses along with the designation of the national topographic map sheet at scale 1:5,000 and the national topographic map sheet at scale 1:2,000.

Article 5. Accuracy of Maps

1. The root mean square error of geographic objects represented on national topographic maps at the established map scale shall not exceed the following values:

a) 0.5 mm on the map for plain areas, hills, and low mountains;

b) 0.7 mm on the map for high mountains and hidden areas.

2. The root mean square error of elevations of geographic objects represented on national topographic maps shall not exceed the values specified in Table 2 below:

Table 2

For concealed areas and particularly difficult areas, these errors may be increased by 1.5 times.

3. The maximum permissible error in planimetry and elevation of geographic objects is 2.5 times the error prescribed in Clauses 1 and 2 of this Article. During inspection, the largest error shall not exceed the maximum permissible error. The number of cases where the error exceeds 2.0 times the error prescribed in Clauses 1 and 2 of this Article shall not exceed 5% of the total number of inspected cases. In all cases, errors shall not be systematic.

Article 6. Product Format

National topographic maps at scales of 1:2,000 and 1:5,000 include digital national topographic maps and paper-based national topographic maps. Digital national topographic maps have one of the formats GeoPDF, PDF, GeoTIFF, TIFF, EPS, ECW, JPEG, and are accompanied by metadata files.

Chapter II

CONTENT AND SYMBOLS

Article 7. Content of the National Topographic Map at scales of 1:2,000 and 1:5,000

1. The National Topographic Maps at scales of 1:2,000 and 1:5,000 are established based on the national geographic database, including the following groups of data layers:

a) Mathematical base layer group;

b) Group of topographic data layers;

c) Group of hydrographic data layers;

d) Group of population data layers;

đ) Group of transportation data layers;

e) Group of national border and administrative boundary data layers;

g) Vegetation cover data layer group.

2. The content of the National Topographic Maps at scales of 1:2,000 and 1:5,000 is represented by corresponding symbols according to the Model of National Topographic Map Symbols at scales of 1:2,000 and 1:5,000 prescribed in Article 16 of this Circular.

3. The accuracy of representing the elements of the map content must comply with the provisions of Article 5 of this Circular.

Article 8. General Provisions on Expressing Map Content

1. The content of the National Topographic Maps at scales of 1:2,000 and 1:5,000 is represented as follows:

a) Represented by proportional symbols when geographical objects in linear form have widths of 1 meter or more for the scale of 1:2,000 and 2.5 meters or more for the scale of 1:5,000; for geographical objects in area form, they are generally represented by proportional symbols detailed according to each group of map data;

b) Represented by half-proportional symbols when geographical objects in linear form have widths less than 1 meter for the scale of 1:2,000 and less than 2.5 meters for the scale of 1:5,000;

c) Represented by non-proportional symbols for geographical objects that cannot be drawn proportionally or when additional symbolic signs need to be placed between proportional symbols to enhance the visual clarity of the map;

d) Represented by explanatory notes when geographical objects do not have representative symbols or when it is necessary to explain the characteristics of the geographical objects;

2. Elements of content must be presented parallel to the southern frame of the map:

a) Non-proportional symbols except for non-proportional house symbols and symbols representing related geographical objects;

b) Names of populated places, administrative units;

c) Points of elevation, object elevations, distinctive notes;

d) Names of objects belonging to the population layer group are represented by non-proportional symbols and explanatory notes;

đ) Representative symbols for vegetation distribution and soil types.

3. Other symbols and notes are arranged according to the direction of the object, with the top of letters and numbers facing upwards (except for elevation notes and depth contour notes which must face the higher side). Notes not arranged according to the direction of the object may be arranged parallel to the southern frame of the map.

4. All abbreviated notes must strictly follow the provisions set out in Appendix 3 issued together with this Circular.

5. The position of the symbol center is specified as follows:

a) Symbols with basic geometric shapes: the center of the symbol is the center of these basic shapes;

b) Symbolic representations with a base line: the center of the symbol is the midpoint of the base line;

c) Symbols with perpendicular feet or round dots, circles at the foot: the center of the symbol is the vertex of the right angle at the foot or the center of the round dot at the foot;

d) Hollow-footed symbols: the center of the symbol is midway between the two feet;

đ) Linear symbols: the center of the symbol is the middle axis of the symbol.

6. When using symbols to accurately represent the location of geographical objects, the center of the symbol must coincide with the center of the object.

7. When multiple geographical objects overlap and require accurate representation, those with higher priority levels and greater directional significance should be shown first. Geographical objects with lower priority levels should be shown broken or yield to other symbols. The priority levels of geographical objects when represented on the National Topographic Maps at scales of 1:2,000 and 1:5,000 are specifically defined as follows:

a) For independent geographical objects, the priority order for representation is as follows: national survey points; geographical objects with greater directional significance and more durable materials;

b) For linear geographical objects, the priority order is as follows: railway, road from expressway, national highway to provincial road, district road, other roads, water boundary, land use boundary, vegetation boundary;

c) In special cases, symbols can be shifted by up to 0.2 mm but must still comply with the priority levels of geographical objects.

8. When symbols intersect, the symbol occupying the upper spatial position is fully displayed, while the symbol below is broken to avoid crossing the upper symbol (except in cases where specific symbols are provided).

9. Non-proportional symbols with centers within the map fragment, with parts extending beyond the frame not exceeding one quarter of the symbol, are extended outside the frame to complete the display. If the center is close to the edge of the frame, it must be displayed on both adjacent map fragments, with the frame line stopping 0.2 mm away from the symbol.

10. Principles for displaying the names of geographical objects on the map

a) Express names according to existing place names in the geographic database;

b) When names are missing or have changed compared to the place name database, they must be investigated, collected, and standardized according to the provisions of QCVN 37:2011/BTNMT National Technical Regulations on Standardization of Place Names for Map Compilation Work;

c) For areas with high density, the font size can be reduced to two-thirds of the size specified in the symbol;

d) In cases where the map's capacity does not allow for the full display of the names of geographical objects as stipulated in Articles 9, 10, 11, 12, 13, 14, and 15 of this Circular, priority should be given to displaying the names of larger, important, famous, or orientation-related objects;

đ) Geographical objects with wide distribution should display their names within the distribution range of the object and can be repeated at appropriate intervals and aesthetically pleasing distances.

e) Long linear geographical objects should repeat their names at intervals of 10 to 15 centimeters;

g) Geographical objects spanning multiple map fragments should display their names on all fragments if the map's content capacity allows.

Article 9. Provisions on the Content of Mathematical Base Classes

1. The mathematical base group represents the contents about reference systems, map projections, sheet identifiers, map scales, national survey points within the sheet range, and other contents presented outside the map frame as follows:

a) The map projection grid is represented on the map by a perpendicular coordinate grid, geographic corner coordinates;

b) The perpendicular coordinate grid is represented with a density of 0.2 km x 0.2 km for maps at the scale of 1:2,000 and 0.5 km x 0.5 km for maps at the scale of 1:5,000. The perpendicular coordinate grid of adjacent zones is also represented if the map sheet is located at the edge of a projection zone;

c) The inner frame note includes the administrative unit name next to the frame and the adjacent sheet identifier;

d) Contents presented outside the frame include: sheet name, sheet identifier, provincial and district administrative unit names within the sheet range, seam table, symbol explanation, map scale, scale bar, slope gauge, south frame note;

đ) The content of the south frame note in the southeast corner of the outer frame includes the project sponsor, map compilation method, year of compilation, compiling organization, coordinate system information, height, central meridian. For printed maps, additional information about the printing organization and the year of map printing is included;

e) National coordinate points, national elevation points, national coordinate and elevation points, national gravity points, national satellite positioning stations are represented by corresponding symbols.

g) The name of the map fragment shall be taken from the name of the populated place with the most houses within the map fragment. If there is no populated place, the name of the geographic feature occupying the largest area or height within the map fragment shall be chosen;

h) When creating maps, if the land area (or Vietnam's territory) only occupies about 1/4 of the total area or less, it is allowed to join this part to the adjacent map fragment if this part is contiguous with that map fragment. The adjacent map fragment is permitted to expand its frame size (called breaking the frame). The expanded frame boundary must still be based on the longitude or latitude lines up to 1' as the limit for the map fragment.

2. The map frame model and external annotations are specified in Appendix 4 and Appendix 5 issued together with this Circular.

Article 10. Provisions on the content of the population data layer

1. The population data layer represents residential areas and facilities related to residents, including urban residential areas, rural residential areas, industrial zones, special function zones, other residential areas, public facilities, economic, cultural, and social bases.

2. Houses are represented according to solid houses, non-solid houses, and simple houses on the map using corresponding symbols.

3. The representation of houses follows the following principles:

a) Houses with two floors or more must indicate the number of floors;

b) If the distance between two houses is less than 0.3 mm on the map, it is allowed to represent a shared house outline;

c) Prioritize representing the edge of traffic roads, boundaries, and fences of special function zones when they coincide with the house outlines.

4. People's Committees at all levels are represented by symbols placed at the location of the building serving as their headquarters.

5. Represent all fire hydrant outlets, water towers, reservoirs with directional characteristics, meteorological, hydrological, marine, environmental observation stations, and other resource and environmental observation stations; ground-based transmission or antenna towers with heights of 30 meters or more, and all broadcasting and television antennas belonging to radio and television stations at provincial level or higher.

6. The power transmission system includes high and medium voltage transmission lines with voltages of 1 kV or higher and substations. Power transmission lines must indicate voltage ratings, start and end at poles or substations, and must be represented as a system throughout the survey area.

7. For geographic objects represented on the map at a scale without specific symbols defined in this Circular, explanatory annotations must be used to fully represent them.

8. Boundaries of construction projects and special function zones are represented on the map using fence, fortification, land use boundary, and restricted area boundary symbols. Land use boundaries and restricted area boundaries are represented based on documents from competent authorities.

9. Fully represent the names of residential objects as follows:

a) Residential areas;

b) Special function zones including: industrial zones, export processing zones, economic zones, high-tech zones, tourist zones, research and training zones, sports and recreation zones.

c) Public facilities: healthcare facilities, educational facilities...

d) Corporate headquarters, large factories, enterprises;

đ) Supermarkets, shopping centers with an area of 30 mm or more on the map; independent marketplaces...² or more; independent market premises...

e) Religious and belief facilities;

g) Cultural facilities: libraries, theaters, museums, stadiums, sports fields at district level or higher, communal cultural houses at village level or higher, entertainment zones;

h) Meteorological, hydrological, marine, and environmental observation stations, and other resource and environmental observation stations;

i) Independent substations, transmission and reception stations.

10. The name of residential areas must clearly indicate the location of the object, and the name of the residential area belonging to an administrative unit must be arranged within the administrative boundary of that unit. In cases where residential areas are scattered, the name of the residential area should be repeated reasonably; represent the names of residential areas below the village, hamlet, and commune levels. Names of residential wards in urban areas should not be represented.

11. For geographic objects with large shapes spread across multiple map fragments such as farms, plantations, historical sites, export processing zones, industrial zones, golf courses, waste disposal sites, and construction projects, their names need to be repeated at appropriate intervals.

Article 11. Provisions on the content of traffic data layers

1. Traffic data layers reflect the transportation network and related infrastructure, including the road system, railway system, airway, waterway, bridges, tunnels, ports, stations, and other transportation works.

2. The presentation of the transportation system must ensure the connectivity of the road network system, reasonable correlation with dependent works, and relevant technical infrastructure.

3. The road transportation system is presented according to the following levels: expressways, national highways, provincial roads, district roads, and other types of roads.

4. All roads with a length of 10 mm or more on the map and all roads related to border and administrative boundary objects must be fully represented.

5. Common bridges, floating bridges, suspension bridges, multi-level bridges, rotating bridges, and transportation tunnels must be fully indicated.

6. Ferry routes, underground sections, and ferry lines must connect seamlessly with the roads on both sides at ferry terminals. Crossing points over rivers and streams in sparsely populated areas must be fully depicted.

7. Fully represent transportation facilities such as ports, stations, mooring basins, bus terminals, parking lots, prioritizing key nodes and connecting lines.

8. At locations where multiple intersecting roads do not align at the same level (road intersections with overpasses, underpasses...), objects should be shown from a top-down vertical projection. In cases where objects completely overlap geometrically, only the uppermost object should be fully displayed on the map, while related objects below should stop at the point of obstruction.

9. All railway lines must be fully represented using corresponding symbol models.

10. Road embankments and excavations with lengths of 10 mm or more on the map and slopes or depths of 0.5 meters or more must be marked along with annotations. The toe of the embankment and excavation must also be depicted if the distance on the map from the crest exceeds 0.5 mm.

11. Various types of bridges and ferries must be fully represented with annotations according to prescribed models. For vehicular bridges that can be crossed, their length, width, and load capacity must be indicated. Railway bridges do not require technical specifications.

12. When the distance on the map between the crest of the embankment and the half-width of the road, based on scale, is less than 0.2 mm, the crest may be shifted up to 0.2 mm to ensure distinguishability from road symbols but must maintain correlation with adjacent objects.

13. Names of traffic objects shall be depicted as follows:

a) Roads at the district level and above;

b) Urban roads: all street and alley names with widths of 1.5 mm or more on the map must be shown.

c) River ferries, long-distance ferries, ferry terminals, ship terminals;

d) Bridges, tunnels, ports, stations, mooring basins;

đ) Bus terminals, parking lots.

Article 12. Provisions on the content of hydrographic data layers

1. Hydrographic data layers reflect the river system, stream system, canal, ditch, sea, lake, pond, marsh, source of water, shoreline, and other hydrographic objects.

2. Seas, natural rivers, lakes influenced continuously by rivers or tides (without human regulation) and large lakes must be depicted with their water edge lines and water edge lines according to the symbols.

3. When representing rivers and streams, their perennial flow, seasonal flow, uncertain sections, direction of flow, and tidal influence must be shown.

4. Rivers, streams, canals, and ditches with lengths of 10 mm or more on the map must be fully represented, ensuring the connectivity of the hydrographic network consistent with the terrain. Important rivers, streams, canals, and ditches related to borders and administrative boundaries must be fully depicted.

5. Ponds and lakes with areas of 2 mm or more on the map must be fully represented using proportional symbols. Smaller ponds and lakes with areas less than 2 mm may be enlarged to 2 mm to be drawn proportionally for water-scarce regions.² or more must be fully represented by symbols according to scale. It is permitted to enlarge ponds and lakes with areas less than 2 mm on the map.² equal to 2 mm² so that they can be drawn to scale for ponds and lakes in water-scarce regions.

6. Waterfalls, rapids, beaches, flooded areas, etc., must be fully represented using corresponding symbols.

7. Depict sandbars, levees, and sandbanks within rivers and lakes with areas of 1 mm or more on the map using proportional symbols. Sandbars, levees, and sandbanks related to national border demarcation and administrative boundaries with areas less than 1 mm on the map must still be fully represented.² or more. For alluvial deposits, sandbars within rivers and lakes related to national border demarcation and administrative boundary delimitation with areas smaller than 1 mm on the map² must still be fully represented.

8. Beaches (above and below water) along rivers, lakes, and seas with areas of 15 mm or more on the map must be fully represented. Islands in bays must be fully represented using corresponding symbols, without grouping islands together.² or more must be fully indicated. Islands in bays must be fully represented by corresponding symbols, without grouping islands together.

9. Represent hydrographic geographic objects such as levees, dams, dykes, hydrological stations, tide gauge stations, sluices, floodgates, mooring basins, and dyke watchtowers using corresponding symbols.

10. Names of hydrographic objects shall be represented as follows:

a) Rivers, streams, canals, and ditches with lengths of 10 cm or more on the map;

b) Ponds and lakes with areas of 20 mm or more on the map;² /second or more;

c) Above-water and submerged beaches along the coast with areas of 20 mm or more on the map;² /second or more;

d) Beaches along rivers and within rivers with areas of 20 mm or more on the map;² /second or more;

đ) Levees, dikes, dams, and sluices on main rivers, canals, and ditches or those of significant importance;

e) Waterfalls and rapids;

g) Hydrological stations and tide gauge stations;

h) Significant mineral water springs and hot springs.

11. Rivers, streams, canals, and ditches related to borders and administrative boundaries must be fully depicted with their names.

Article 13. Provisions on the Content of Topographic Data Layers

1. The topographic data layers describe the shape and characteristics of the Earth's surface, including: elevation points, depth points, contour lines, and special landforms.

2. A line connecting points with the same elevation value is a contour line. Contour lines are shown on national topographic maps at scales of 1:2,000 and 1:5,000, including: basic contour lines, half-interval basic contour lines, supplementary contour lines, and rough contour lines.

3. On a single map sheet, only one uniform interval of basic contour lines can be displayed to represent the terrain. In cases where different terrains interweave, the appropriate uniform interval of basic contour lines must be selected based on which type of terrain predominates. In exceptional cases, two uniform intervals of basic contour lines may be used for representation but this must be clearly specified in the Technical Design - Estimate.

4. The uniform interval of basic contour lines must be chosen according to the slope of the terrain as stipulated in Table 3 below:

Table 3

5. To enhance visual clarity, depending on the uniform interval of basic contour lines, every three to four basic contour lines should be represented with a thicker line (called the main contour line according to the map symbol model).

6. Half-interval basic contour lines are contour lines located between two basic contour lines.

7. Supplementary contour lines are contour lines with suitable elevations between basic contour lines and half-interval basic contour lines, used to describe special inclinations of the terrain that half-interval basic contour lines cannot clearly represent. Supplementary contour lines must indicate their elevations, except when the elevation values are multiples of one-quarter of the uniform interval of basic contour lines.

8. When basic contour lines fail to fully depict the characteristics of the terrain or special elements such as horseback saddles, low hills, stepped slopes, valleys, etc., and the distance between adjacent basic contour lines exceeds 5 cm on the map, additional half-interval basic contour lines or supplementary contour lines must be shown.

9. Rough contour lines are contour lines with elevation values equivalent to those of basic contour lines, used to represent unstable terrain or data with insufficient reliability.

10. The number of elevation points and elevation annotations should range from 10 to 15 points per 1 dm² on the map in mountainous areas and high mountains, and from 15 to 20 points per 1 dm² on the map in plains and hilly areas.² on maps in mountainous areas, high mountains, and 15 to 20 points per 1 dm² 11. In special cases, such as when depicting elevations in densely populated areas or regions with regularly changing terrain, the number of elevation points and elevation annotations may be reduced but not less than 8 points per 1 dm² on the map in mountainous areas and high mountains, and 10 points per 1 dm² on the map in plains and hilly areas.

11. In special cases such as when representing elevation in densely populated areas, regions with uniformly changing terrain, the number of elevation points and annotations may be reduced but not fewer than 8 points per 1 dm² 12. In flat areas where terrain cannot be depicted using contour lines, the number of elevation points should range from 25 to 30 points per 1 dm² on the map.² 11. In special cases, such as when depicting elevations in densely populated areas or regions with regularly changing terrain, the number of elevation points and elevation annotations may be reduced but not less than 8 points per 1 dm² on the map in mountainous areas and high mountains, and 10 points per 1 dm² on the map in plains and hilly areas.

12. In flat areas where contour lines cannot represent the terrain, the number of elevation points shown should range from 25 to 30 points per 1 dm² 13. Elevation points should be selected at characteristic locations including: intersections of roads, bends in river and canal banks, base points of orientation features, mountain peaks, horseback saddles, basin bottoms, cave entrances, pit mouths...

13. Elevation points need to be selected at characteristic locations including: intersections, bends of riverbanks and canal banks, bases of orientation features, mountain peaks, saddles, basins, cave mouths, pit openings...

14. Slope indication lines are fixed-length straight lines placed perpendicular to contour lines at positions indicating downward slopes such as mountain peaks, depressions, horseback saddles, unclearly defined slopes, and all contour lines near the edges of the map sheet must have slope indication symbols.

15. For areas of sand dunes and sand hills, in addition to representing sand terrain symbols, sketch contour lines must also be shown when the height of the sand dunes or sand hills reaches values that can be represented from one basic contour interval upward.

15. For sand dunes and sand mounds, in addition to showing sand terrain symbols, rough contour lines should also be drawn when the height of the sand dunes or mounds reaches a value that can be represented by at least one basic contour line.

Article 14. Provisions on the content of the vegetation cover data class

1. The vegetation cover data class reflects forests classified according to forest canopy density, annual crops, perennial crops, mixed vegetation, vegetation in residential areas, and on surface structures.

2. Vegetation areas with an area of more than 20 mm on the map must be shown. In cases where vegetation areas have an area of more than 4 cm on the map, the name of the plant must be additionally noted.² or more must be shown. For vegetation areas with areas of 4 cm or more on the map² or more, annotations of tree names must be added.

3. For vegetation areas with multiple types of plants interwoven, priority should be given to showing the type of plant that occupies the majority but must occupy at least 30% of the area. In cases where no plant meets this criterion, it must be shown according to the regulations for mixed vegetation.

4. The boundaries of vegetation areas must be enclosed by vegetation boundary symbols. Priority should be given to showing linear geographic objects when the vegetation boundary coincides with other linear objects such as administrative boundary lines at various levels, roads, river banks, canals, and other geographic objects.

5. The names of all forest areas: national parks, nature reserves, species and habitat conservation areas, scenic protection areas, scientific research and experimental forest areas, national botanical gardens, and other named forest areas must be shown.

6. All independent trees and tree clusters with a height of 10 meters or more must be shown.

Article 15. Provisions on the content of the national border and administrative boundary data class

1. The national border and administrative boundary data class reflects the national border line, the system of national boundary markers; base points and baseline used to calculate the width of Vietnam's territorial sea, distinctive features of the national border; and the administrative boundary lines at various levels and the system of administrative boundary markers.

2. The national border line and national boundary markers must be fully, accurately, and consistently depicted according to the standard national border map. When there is no standard national border map, the national border line and national boundary markers shall be transferred and drawn according to the provisions of Article 12 of Circular No. 17/2018/TT-BTNMT dated October 31, 2018, issued by the Minister of Natural Resources and Environment on technical procedures for establishing and updating the standard national border map set and depicting the national border line and national sovereignty territory on surveying products and maps, and map publications. The national border line must be depicted continuously without interruption.

3. Administrative boundary lines and administrative boundary markers at various levels must be fully depicted according to administrative boundary files and maps. Administrative boundary lines at various levels must be depicted continuously without interruption.

4. The depiction of the national border line and administrative boundary lines at various levels must follow the following principles:

a) In cases where the national border line and administrative boundary lines at various levels coincide with half-scale linear objects or linear objects depicted at scale but with a width on the map less than 1 mm, they may be shifted and depicted offset on both sides of the linear object, each segment being from 3 to 4 tick marks apart. The distance from the national border line and administrative boundary lines at various levels to the linear object on the map is 0.2 mm;

b) In cases where the administrative boundary lines at various levels coincide with linear objects depicted at scale on the map with a width of 1 mm or more, the administrative boundary lines at various levels must be depicted inside the linear object.

c) At the end or beginning of a segment of the national border line and administrative boundary lines at various levels, the symbol must be fully depicted without extra strokes or missing dots. Three-way and four-way intersections of the national border line and administrative boundary lines at various levels must be clearly depicted.

5. Administrative unit names must be depicted according to the following principles:

a) The commune name is arranged in the central area of the commune. In cases where the commune area is divided across multiple map sheets, the commune name must be shown on the sheet with the largest area or the most concentrated population, while other sheets only show the commune name outside the map frame. The commune name includes the common noun and does not use abbreviations;

b) The district name is shown below the name of the town which is the district capital. If the town name coincides with the district name, the district name need not be shown.

Article 16. Symbolization of national topographic maps at scales of 1:2,000 and 1:5,000

The symbolization of national topographic maps at scales of 1:2,000 and 1:5,000 is detailed in Appendix 2 attached to this Circular. The symbolization of national topographic maps at scales of 1:2,000 and 1:5,000 shall be designed and used according to the following principles:

1. Units of length (dm, cm, mm) and units of area (dm², cm², mm²) are dimensions measured on the map. Units of meters (m) or square meters (m²) are actual sizes of geographic objects.

2. The size and line weight of symbols are noted next to the symbol in millimeters. If the line does not indicate line weight, the default line weight is 0.1 mm. Proportional symbols only note the size specified for the non-proportional part, the rest is drawn according to the map scale. Symbols distributed evenly across the area, if no size is specified, are drawn similarly to the model, if specified, they must be drawn according to the specification. When the area representing the object is less than 1 cm² , the distance between symbols may be reduced but not more than 70% of the specified distance in the symbol model, provided that the geographic object represented remains clearly readable and distinguishable.

3. The font size specified in the symbol is the printed font size, measured in points (pt).

4. The symbolization of national topographic maps at scales of 1:2,000 and 1:5,000 is designed in CMYK color system, with detailed color chart in Appendix 1 attached to this Circular.

Chapter III

IMPLEMENTING PROVISIONS

Article 17. Effective Date

1. This Circular takes effect from January 23, 2020.

2. This Circular abolishes the content of the symbolization of topographic maps at scales of 1:2,000 and 1:5,000 in Decision No. 1125/ĐĐBĐ dated November 19, 1994 of the Director General of the Land Administration General Department.

3. This Circular abolishes Clause 1.4 Section 1 General Provisions; Section 2 Mathematical Basis and Accuracy of Topographic Maps; Section 3 Map Content in Decision No. 17/2005/QĐ-BTNMT dated December 21, 2005 of the Minister of Natural Resources and Environment promulgating Technical Regulations for Establishing Topographic Maps at Scales of 1:2,000 and 1:5,000 Using Digital Image Technology.

Article 18. Responsibility for Implementation

1. Ministries, ministerial-level agencies, agencies under the Government, People's Committees of provinces and centrally governed cities, and relevant organizations and individuals are responsible for implementing this Circular.

2. During implementation, if there are any difficulties, agencies, organizations, and individuals should promptly report to the Ministry of Natural Resources and Environment for consideration and decision./.