Past and Present Practices of Topographic Base Map Database Update in Nepal
Topographic Base Maps (TBMs) are those maps that portray ground relief as the form of contour lines and show planimetric details. Various other maps like geomorphological maps, contour maps, and land use planning maps are derived from topographical maps. In this constantly changing world, the update...
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| Format: | Article |
| Language: | English |
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MDPI AG
2020-06-01
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| Series: | ISPRS International Journal of Geo-Information |
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| Online Access: | https://www.mdpi.com/2220-9964/9/6/397 |
| _version_ | 1827714941823483904 |
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| author | Nimisha Wagle Tri Dev Acharya |
| author_facet | Nimisha Wagle Tri Dev Acharya |
| author_sort | Nimisha Wagle |
| collection | DOAJ |
| description | Topographic Base Maps (TBMs) are those maps that portray ground relief as the form of contour lines and show planimetric details. Various other maps like geomorphological maps, contour maps, and land use planning maps are derived from topographical maps. In this constantly changing world, the update of TBMs is indispensable. In Nepal, their update and maintenance are done by the Survey Department (SD) as a national mapping agency. This paper presents the history of topographical mapping and the reasons for the lack of updates. Currently, the SD is updating the TBM database using panchromatic and multispectral images from the Zi Yuan-3 (ZY-3) satellite with a resolution of 2.1 and 5.8 m, respectively. The updated methodology includes the orthorectification of images, the pansharpening of images, field data collection, digitization, change detection, and updating, the overlay of vector data and field verification, data quality control, and printing map production. A TBM in the Dang district of Nepal is presented as casework to show the changes in the area and issues faced during the update. Though the present digitizing procedure is time-consuming and labor-intensive, the use of high-resolution imagery has made mapping accurate and has produced high-quality maps. However, audit and automation can be introduced from the experiences of other countries for accurate and frequent updates of the TBM database in Nepal. |
| first_indexed | 2024-03-10T19:07:29Z |
| format | Article |
| id | doaj.art-da2a9bf0364640548cdfae292fd7d750 |
| institution | Directory Open Access Journal |
| issn | 2220-9964 |
| language | English |
| last_indexed | 2024-03-10T19:07:29Z |
| publishDate | 2020-06-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | ISPRS International Journal of Geo-Information |
| spelling | doaj.art-da2a9bf0364640548cdfae292fd7d7502023-11-20T04:02:56ZengMDPI AGISPRS International Journal of Geo-Information2220-99642020-06-019639710.3390/ijgi9060397Past and Present Practices of Topographic Base Map Database Update in NepalNimisha Wagle0Tri Dev Acharya1Survey Department, Government of Nepal, Minbhawan, Kathmandu 44600, NepalInstitute of Industrial Technology, Kangwon National University, Chuncheon 24341, KoreaTopographic Base Maps (TBMs) are those maps that portray ground relief as the form of contour lines and show planimetric details. Various other maps like geomorphological maps, contour maps, and land use planning maps are derived from topographical maps. In this constantly changing world, the update of TBMs is indispensable. In Nepal, their update and maintenance are done by the Survey Department (SD) as a national mapping agency. This paper presents the history of topographical mapping and the reasons for the lack of updates. Currently, the SD is updating the TBM database using panchromatic and multispectral images from the Zi Yuan-3 (ZY-3) satellite with a resolution of 2.1 and 5.8 m, respectively. The updated methodology includes the orthorectification of images, the pansharpening of images, field data collection, digitization, change detection, and updating, the overlay of vector data and field verification, data quality control, and printing map production. A TBM in the Dang district of Nepal is presented as casework to show the changes in the area and issues faced during the update. Though the present digitizing procedure is time-consuming and labor-intensive, the use of high-resolution imagery has made mapping accurate and has produced high-quality maps. However, audit and automation can be introduced from the experiences of other countries for accurate and frequent updates of the TBM database in Nepal.https://www.mdpi.com/2220-9964/9/6/397topographic base mapnational mapping agencyupdateshistoryZY-3Nepal |
| spellingShingle | Nimisha Wagle Tri Dev Acharya Past and Present Practices of Topographic Base Map Database Update in Nepal ISPRS International Journal of Geo-Information topographic base map national mapping agency updates history ZY-3 Nepal |
| title | Past and Present Practices of Topographic Base Map Database Update in Nepal |
| title_full | Past and Present Practices of Topographic Base Map Database Update in Nepal |
| title_fullStr | Past and Present Practices of Topographic Base Map Database Update in Nepal |
| title_full_unstemmed | Past and Present Practices of Topographic Base Map Database Update in Nepal |
| title_short | Past and Present Practices of Topographic Base Map Database Update in Nepal |
| title_sort | past and present practices of topographic base map database update in nepal |
| topic | topographic base map national mapping agency updates history ZY-3 Nepal |
| url | https://www.mdpi.com/2220-9964/9/6/397 |
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