LGN is a raster database with land use information stored in 25*25 m grid cells. This database has been a product of Alterra since the 1980s and meets the need for current and accurate data on Dutch land use. It can also be used to monitor changes to land coverage and use over time.
Different versions of the LGN database
Seven versions of the LGN database have been produced since 1986. The newest version in this series will be available from 1 January 2014. The different versions each represent land use in one particular year. Comparisons between the different databases, LGN3, LGN4, LGN 5, LGN6 and LGN7, illustrate the changes that have taken place with regards to methodology, the development of the legend, the level of accuracy and land use.
LGN1 and LGN2
The first two versions of the LGN database were experimental databases with limited accuracy and clear shortcomings. In LGN3 these limitations were overcome and the arrival of LGN3plus ensured that the usefulness of the database for environmental analysis was strongly improved.
Changes to land use over time have been able to be observed since LGN3. These are changes to agricultural areas , greenhouses, orchards, forests, water, urban areas, infrastructure and nature.
How the LGN database could be utilised was further expanded with LGN4. For example, agricultural crops could be combined with Top10 Vector property boundaries. Being able to trace changes in land use was also made possible.
LGN5’s specifications are the same as LGN4’s. The most important difference is that it is based more on satellite images. These have provided improved crop classification input. There have also been several further technical improvements that have made the editing and management of the database easier, for example the geodatabase is a sheet-free version of the Top 10 Vector. The LGN5 database is a collection of databases, just as LGN4 was. In addition to the country-wide raster file, the LGN5 grid, there is also an LGN5 that maps crops, a monitoring file, ( the ‘LGN5-mon’) and further diverse thematic aggregations of the LGN5 database.
The LGN 6 database has the same amount of files as LGN5. The most important improvements are:
- The geometry and main class themes are now fully based on the Top10 Vector database (2006 Version).
- In urban areas data from the Soil Use database from the Central Office of Statistics (BBG2003) and the Built-up Areas database from VROM (BG2003) is integrated.
- Natural grasslands, dunes and swamps are taken from the ‘Natural Landscape Standard Map 2007’ (BKN2007)
- The forests and heath have been reclassified based on satellite images from 2007/2008.
Improvements to the LGN database include integration with the most current spatial databases, such as the Kadaster’s topographic base date (Top10NL, version 2012), the Land Parcel Information System 2012 (LPIS2012), the Netherlands digital land use map 2008 (BBG2008) and the Basic Nature Map 2012 (BKN2012). In addition to this, use is made of a higher temporal satellite-information resolution made available via the National Satellite Data Portal (NSD) green monitor. This has resulted in the classification of agricultural crops being vastly improved. Furthermore the swamps have been more clearly defined due to the fact that Top10NL’s fields include swamps, reeds and bogs.
In the past, the LGN database was used in water management, spatial planning and environmental management.