Bhutan: sources of geospatial data

Administrative boundaries help connect population statistics, field research and project geography. This discussion retains a walkthrough of Bhutan's geospatial sources and the historical boundary files used in it. Each map identifies its source and edition; visual agreement alone does not establish an official boundary or a valid statistical join.

For current work, begin with the National Land Commission Secretariat and its NSDI boundary catalogue, which lists dzongkhag and gewog records. Reconcile those geometries with the codes and reporting areas used by the statistics being analysed. The Bhutan demographic and impact assessment discussion develops this process. The separate ICIMOD service walkthrough explores thematic layers.

Bhutan's official geoportal

The earlier Bhutan Geo Portal supported sharing maps, datasets and metadata. Its original NLCS description attributed development to the Center for GIS Coordination and the National Land Commission, with support from ICIMOD and SERVIR-Himalaya, a joint initiative involving USAID, NASA and ICIMOD.

The original walkthrough recorded the following applications. The archived links and historical service URLs remain useful for tracing provenance; consult the current custodian for an operational replacement and the underlying data.

The portal's main entry point was unavailable during the original investigation, and the application pages did not provide the required boundary downloads. That observation concerns the earlier portal. The current NSDI catalogue provides a new starting point.

Humanitarian Data Exchange

The Humanitarian Data Exchange is maintained by OCHA. Its Bhutan collection and geodata filter lead to spatial datasets. The original investigation used Bhutan administrative boundaries, levels 0–2, uploaded by Ahmadou Dicko. The record described level-0 and level-1 geometries as suitable for linkage to its corresponding population tables.

The recorded resource links are retained below. Their identifiers document the original edition; follow the dataset record to check for revised resources, effective dates and terms.

The retained GeoJSON conversion is the file examined in the original notebook. Its first rendering did not distinguish the expected administrative levels. That is a reason to inspect attributes, geometry types and the conversion process before judging the provider dataset. It does not establish a defect in the current HDX release.

GADM administrative boundaries

GADM offers administrative geometries for many countries and levels. The original walkthrough used its version-3 country catalogue and retained background links to UC Davis and its Center for Spatial Sciences. The current country download page identifies version 4.1. The retained comparison here remains version 3.6, with country, first-level and second-level geometries converted to GeoJSON. Second-level units should be matched to the edition's attributes and an official geographic crosswalk before describing them as villages or joining statistics.

The original version-3.6 downloads remain recorded for reproducibility:

The country outline loads first. District and second-level boundaries are optional because they add approximately 1.2 MB and 5.3 MB. The finer lines use a lighter weight. These are the already-published historical files, rather than a new download or a claim that GADM certifies current official boundaries.

The earlier comparison preferred GADM's rendering for the intended administrative map. Current use also requires checking names, identifiers, parent units, effective dates and coverage against the responsible Bhutanese agencies. GADM's terms distinguish permitted academic and non-commercial uses from redistribution and commercial use requiring permission. Public rendering and authenticated archive access should follow the recorded terms for the selected edition.

MapCruzin

MapCruzin is an independent GIS research and data provider. Its Bhutan downloads page lists:

In the original investigation, its administrative file appeared to reproduce the geometry encountered through HDX. That was a visual observation, rather than an independent verification or a checksum comparison. A second distributor may carry the same upstream data, so use provenance to establish whether a comparison supplies independent evidence.

Other sources retained from the investigation

The archived NLCS mapping description lists topographic, thematic, cadastral and project mapping responsibilities. The earlier notebook recorded topographic maps at 1:50,000 and 1:25,000, cadastral and administrative maps, physical maps and guide maps as available on request. Its former topographic viewer used a 56-tile reference arrangement. Treat those details as historical catalogue notes and confirm current products with NLCS.

The Global Map data archives preserve the Global Mapping Project, which began in 1996 through cooperation among national mapping authorities. Its design comprised eight standardised layers covering the globe, with national agencies supplying or authorising their country information. The project was coordinated by ISCGM with a secretariat at Japan's Geospatial Information Authority. Its 2016 closure transferred the data to an archival setting; the earlier catalogue records the August 2 resolution and December 19 website closure. Bhutan packages include gmbt10 and gmbt20. Check each package's metadata, scale, dates and non-commercial-use terms before combining it with more recent sources.

Reproduce the comparison

The maps load retained GeoJSON only after a reader chooses Load map. They use D3's geographic Mercator projection fitted to the selected extent, with polygon winding normalised for rendering. The earlier notebook used a reflected identity projection and automatic attachment reads. The current implementation preserves the source comparison while giving each request a size limit, timeout, retry action and readable diagnostics.

Record the original dataset, conversion procedure, coordinate reference system, feature identifiers and geometry checks alongside analytical results. For a current assessment, use the dataset curation guide and spatial baseline analysis to connect the selected boundaries with defensible survey and statistical units.