Topographic base map update project of Nepal

This project was Nepal government's Project. I worked as technical lead in a group who did all the complete database updating, map making along with field verification.

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. 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

Some figures from my paper "Past and Present Practices of Topographic Base Map Database Update in Nepal". This paper tells about how the topographic base map is done now and how was it done in past.
Zoomed view of Topographic map.
Workflow followed while doing this project and the current status of topographic map update of Neapl