Information on the digitalisation and the resulting geodata on land suitability in Switzerland.
From a map to geodata
In 1980, the then Federal Offices of Spatial Planning, Agriculture and Forestry published a land suitability map of Switzerland on a scale of 1:200,000, whose contents were interpreted and mapped at the Federal Laboratory for Agricultural Crop Production in Reckenholz, with the help of numerous data sources (maps, aerial photographs) from the 1970s. A few years later these maps were digitalised at the Geographical Institute of the University of Bern to be used for different purposes. After the FSO became aware of the existence of this digital land suitability map, in 1994 the four map quadrants, which had originally been recorded separately, were merged into a consistent data set and with the permission of the paper map publishers transferred to the GEOSTAT range of data.
In 2000, this digital data was re-examined regarding its location accuracy and subsequently rectified und geometrically improved using the rasterized Swiss topographic map 1:200'000 as reference. The topographic landscape model VECTOR200 of the Federal Office of Topograpy contributed the national boundary as well as the lake shore lines, thus creating a clear reference for most of the linear map elements without direct pedologic substance.
Each mapping unit in the Swiss soil suitability map is characterised by a code formed of a capitel letter followed a number. The letters represent 25 different physio-geographical units. The numbers indicate different form elements of landscapes, arranged according to type of bedrock, slope gradient and slope inclination. Each mapping unit includes one or several pedological soil category. The altogether 144 different mapping units are aggregated in the map to 18 color-coded groups according to their estimated soil suitability for various agricultural usages. Hence, in the first priority agricultural criteria were use for this classification.
|B||Basins and valleys of the Fold and Table Jura|
|C||Longitudinal valleys of the Fold Jura|
|E||Mountain ranges of the Chain Jura|
|F||Plains of the lower Swiss Central Plateau|
|G||Slightly undulated moraine hill country|
|H||Lower molasse hill country, partly covered by moraines|
|J||U-valleys of the Swiss Central Plateau|
|K||Middle molasse hill country, partly with glacial transformation|
|L||Drumlin landscapes with stronger relief|
|M||Higher molasse hill country with strong erosion relief (Hörnli)|
|N||Higher molasse hill country with strong erosion relief (Napf)|
|O||Predominantly sandy mollasse at the fringe of the Alps|
|P||Predominantly conglomerate at the fringe of the Alps|
|Q||Wide alpine valleys|
|R||Narrow alpine valleys|
|S||Alpine flysch and Grison slate landscape, predominantly in the northern Alps|
|T||Alpine Grison slate landscape in the upper Rhone valley and in Ticino|
|U||Alpine limestone mountains|
|V||Alpine crystalline mountains of hard bedrock (granite, orthogneiss)|
|W||Alpine crystalline mountains of relatively easily weathered bedrock (paragneiss)|
|X||Molasse at the fringe of the Alps in Ticino, partly covered by moraines|
|Y||Valley landscapes (south side of the Alps)|
|Z||Plains (Magadino, Mendrisio)|