Horticultural land is any site dedicated to the planting of vegetables, fruit trees and flowers as well as crops. These sites are generally classified as open space.
If horticulture is located within urban sites, then it is seen as constituting allotments and thus urban open space, resulting in a classification as settlement (old ATKIS Basis-DLM, Version 3.2). In the new Basis-DLM (AAA-model, Version 6.0) there is an explicit attribute allotment, making the older form of classification redundant. This can lead to regionally differentiated migration effects in the changeover from the old to the new ATKIS model for horticulture as well as the proportion of land assigned to either settlement area or open space.
In the new ATKIS model (AAA-Model, Version 6.0), allotment garden was introduced into the object category sport, leisure and recreation area. As this land-use category did not exist in the previous ATKIS Model (Version 3.2), horticultural land within an urban site was previously considered to be allotments within the IOER Monitor and hence forms of urban open space. As a result of the AAA Migration, areas of the object type horticultural land have been temporarily reclassified in some federal states (e.g. Hesse and Thuringia) as allotment gardens (urban open space and thus settlement area). In other federal states (e.g. Baden-Württemberg and Lower Saxony), such areas are retained for the time being as horticultural land (agricultural usage and thus open space).
As a consequence, the settlement area is temporarily increased or decreased in these federal states. As part of the comprehensive updating by the State Land Survey Agencies, these affected sites will be individually assessed and, in some cases, reclassified. In some states (e.g. North-Rhine Westphalia), classification is realised by overlaying such sites with the urban site (similar to the method within the IOER Monitor) so that here there are practically no migration effects.
[Source: AdV (2008): GeoInfoDok, ATKIS-Objektartenkatalog Basis-DLM, Version 6.0]