Hydrological Factors in the Content Criteria of Provincial and District Administrative Maps

Hydrological elements in the content criteria of provincial and district administrative maps (Illustrated example)

Specifically, Clause 3, Article 27 of Circular 47/2014/TT-BTNMT stipulates the hydrological elements in the content criteria of provincial and district administrative maps as follows:

- The coastline is depicted to the inner frame of the map; depending on the map scale, generalization must ensure retention of the characteristic features of each type of coastline and major river estuaries;

- Depict Vietnamese islands according to the following criteria: Depict all islands with an area ≥ 0.5 mm² on the scale map; islands with an area <0.5 mm² on the map can be depicted with non-scale representation and can be selectively shown but must ensure shape, orientation, and distribution density; islands related to national border factors and administrative boundaries are prioritized for selection; distinguish coral islands, other islands, rocks, shoals, reefs, other areas on the sea as per the requirements of the competent state authority;

- Depict the basic characteristics of river systems; rivers, streams, canals with a length ≥ 5 cm on the map; depending on the geographical characteristics of each area, this criterion can be increased or decreased by 2 cm. Prioritize depicting rivers, streams, canals related to national borders and administrative boundaries;

- Rivers, streams, canals with a width ≥ 0.7 mm on the map are depicted to scale; narrower rivers, streams are depicted with a single line with the line thickness gradually reducing towards the upstream. Selectively depict rivers, streams, canals with single lines ensuring density and distribution shape;

- Depict lakes with an area ≥ 10 mm² on the map; lakes <10 mm² that are related to national border factors, administrative boundaries, or water-scarce areas;

- Depict islets and sandbanks on rivers with an area on the map ≥ 2 mm²; islets and sandbanks <10 mm² and ≥ 0.5 mm² that are related to national border factors, administrative boundaries;

- Note hydrological place names as follows:

- Names of seas, bays, gulfs, straits, major river mouths; names of rivers with a length ≥ 7 cm on the map; lakes with an area ≥ 25 mm² on the map;- Names of major islands and all archipelagos; must annotate with the names of the managing district, provincial administrative unit, and the name of the country "Vietnam" according to the competent state authority's requirements.

Priority is given to notes for geographical objects related to national borders and administrative boundaries.

More details can be found in Circular 47/2014/TT-BTNMT, effective from August 22, 2014.

Thuy Tram

>> CLICK HERE TO READ THIS ARTICLE IN VIETNAMESE