Object key
In geology and other geosciences, the object key is the classification of natural objects on the earth's surface . They are used to record the rocks and their formations, the landforms , bodies of water and land use as well as partially the properties and boundaries.
Technical disciplines and spatial planning also include buildings and other man-made objects in the classification, e.g. B. gravel pits and quarries, mines and heaps, traffic routes , pipes, utility ponds, etc.
The object key is broken down into main groups with gradual refinement. Such main groups can be defined according to the following criteria, for example:
- Geology: according to three rock groups (igneous rocks, sediments, metamorphic rocks) or according to the five geological epochs; also according to the type of outcrops, drilling profiles, etc.
- Agriculture and forestry: types of land use (see below), forest types, wasteland, etc.
- Soil science: soil forms and types, bedrock, exposure, hydrogeology
- Geodesy and spatial planning: 10–15 types of land use (cultural classes).
The further details are mainly based on the forms of decimal classification and include e.g. In geology, for example, there are several 100 types of rock (depending on local characteristics, thousands), dozen drilling and exploration methods, as well as structure or grain sizes .
For tax purposes, technology and spatial planning, on the other hand, surface features and profitability are of particular importance. Thus, the land use detection used the EU for. B. the following 13 main classes:
- Settlement areas (including traffic areas)
- Arable land
- Permanent crops
- Grassland
- Deciduous and mixed forest
- Coniferous forest
- Alpine mats
- Mountain pines, Krummholz
- Rock faces
- Sparse vegetation
- glacier
- Wet areas
- Bodies of water.
Their numbering represents the guide number, the further subdivision into about 50 classes takes place in each case with a different level of detail.