National Land Surveying and Mapping Center. Republic of China(Taiwan)National Land Surveying and Mapping Center. Republic of China(Taiwan)

Basic Topographic Map

• Basic topographic maps (BTM) are topographic maps at scales of 1/5,000, 1/25,000, 1/50,000 and 1/100,000 defined by the Ministry of the Interior (MOI). The contents of BTM are major national lands’ description including relief, both natural and man-made features, and basic geographic data
• The analog photogrammetric method was adopted at the initial stage of BTM mapping. In response to the advancement of photogrammetry and GIS technology and in coordination with NGIS requirements, a pilot mapping plan with digital photogrammetric method was conducted in 1995 and digital photogrammetry was comprehensively adopted since 1997 at scale of 1/5,000.
• The BTM mapping project began in the year of 1976 by MOI. Since 2006, NLSC was assigned the BTM update jobs by MOI. The revision of BTM continues. Until 2021, the 5-year update target set by the Land Surveying and Mapping Act was achieved. The latest BTM’s production year and areas of coverage is shown as follow.

The latest BTM’s production year and areas of coverage

Economic Development Version of Topographic Maps

• MOI began Economic Development Version of Topographic Mapping in 1995 for various professional applications. The Economic Development Version of Topographic Mapping was made with reduction by drawing from 1/5000 scale base map since 2008. The status of the latest production year and areas of Economic Development Version of Topographic Maps at scales of 1/25,000, 1/50,000, and 1/100,000 are shown as below respectively.

1/25,000 scales	1/50,000 scales	1/100,000 scales

 

Digital Terrain Model(DTM)

• The 5-meter grid DTM of Taiwan was made by MOI during 2004~2006 and has been revised along with the yearly planned BTM revision since 2008.
• For the purpose of sharing and exchanges of DTM products, its relevant results and archived management, MOI requested production organizations to send their DTM productions to MOI since November 2013.
• Due to the different surveying and production method, data format, and quality standard of DTM, MOI is dedicated to the integration of DTM productions from all organizations and development specification for integration and applications.

NGIS Basic Topographic Maps Website

• The BTM is one of the 9 major databases of National Geographic Information System (NGIS) and the NGIS Basic Topographic Maps website(https://bmap-nlsc.moi.gov.tw/) is available at the National Land Surveying and Mapping Center, Ministry of the Interior ( NLSC, MOI). The system only provide access to inquiry contents of work plan, specification and result data of BTM. The map browsing service is provided by platform of National Land Survey Information Integration/Exchange/Warehousing Service Network (https://whgis-nlsc.moi.gov.tw). The system provides latest project, partial update, and latest completed maps from time to time.