Global Administrative Unit Layers (GAUL)
Purpose
The Global Administrative Unit Layers (GAUL) aims at compiling and disseminating reliable spatial information on administrative units for all countries.
The Gaul Project aims at:
- overcoming the fragmentation of the global dataset;
- promoting a unified coding system;and
- keeping track of historical changes occurring in the shapes and extent of administrative units.
An updated version of the GAUL set is released through Geonetwork every year.
Characteristics of the GAUL dataset
- Level 0 (country), Level 1 (provinces) and Level 2 (districts) are provided with the global layers. Lower levels (level 3, level 4, level5), when available, are carried out on individual country layers.
- Country boundaries comply with the latest version of the UNCS International Boundaries Map (version 5, November 2005).
- The coastal line is mostly compliant with the International Boundary map delivered by UNCS. However, some countries (e.g. Timor-Leste) have been updated according to satellite images (e.g. Landsat ETM). The coastal line will be totally reviewed in the next release of the GAUL (GAUL 2008).
- Data is not always officially validated by national authorities and cannot be distributed to the general public. A disclaimer should always accompany any use of GAUL data.
- Country maps which have been copyrighted and validated by the Second Administrative Level Boundaries (SALB) have been integrated into the GAUL Set layers. The SALB Dataset aims at improving the availability of information about administrative boundaries down to the second subnational level.
- GAUL keeps track of administrative units that have changed for political reasons. Changes implemented in different years are recorded on different layers.