Soil Associations 1990

Methodology

Aey (1991) wrote a guide for the preparation of a Concept Map of Soil Associations in the entire city. This guide was based on: 1) the method described by Grenzius (1987) for the preparation of a Soil Association Map for West Berlin; 2) the Map of Soil Associations by Grenzius which was transferred into the spacial reference system of the Environmental Information System (UIS) by Fahrenhorst, Haubrok, and Sydow (1990). No Soil Association Map of this or a similar kind existed for East Berlin. The bases for the development of the soil association map of West Berlin were the excavations and drilling stock samples conducted in all of West Berlin. These were conducted in forest plantations and agricultural areas under consideration of geomorphological-hydrological conditions, and, in populated areas, under consideration of uses. All parent rock and most uses, with the exception of industrial areas, were surveyed several times, and mapping was begun. The evaluation of this mapping enabled analogical conclusions for soil conditions at unmapped areas.

The comprehensive soil science studes used for the previous Map of Soil Associations in West Berlin have verified the Map for many areas, such as forest and agricultural areas (farmland). The map is to be regarded as partially verified for areas with lesser degrees of soil science studies. Such detailed soil mapping for East Berlin only exists for forests. All derivations and determinations of soil associations for East Berlin – except for forest plantations – had to be made on the basis of analogical conclusions and existing material, such as geological and topographical maps, soil maps, and area uses, etc.. The accuracy, informational content, and age of this material varied greatly.

More precise classification schemes for soil associations, as well as the definition of new soil associations not yet described by Grenzius were enabled by maps and soil studies conducted in West Berlin after the publication of the West Berlin Soil Association Map, as well as existing soil maps for East Berlin, particularly for forest plantation areas.

The existing map for East Berlin is to be regarded as confirmed only for forest plantations. It is a concept map for all other areas. This is the reason why the entire map itself is to be regarded only as a concept map with some confirmed areas.

The map scale of 1 : 50,000 does not allow the spatial distribution of individual soil types to be portrayed. Unifying units had to be selected. Soils of spacial and material coherence were combined as soil associations.

The naming of the soil associations was based on the interactions of characteristic soils. The first and last soil of the association were given in the German system, and, usually, one of the soils that characterizes material translocations (Grenzius 1987). This interacting system, or the link between soils in areas still extensively near-natural is characterized in the map legend by “-”.

Near-natural soils are found only in loosely settled areas.

The structures of soils in settled areas have sometimes been greatly altered by human influences. Anthrosols appear randomly next to each other and are connected in the legend by “+”.

The legend is structured according to the degree of anthropogenic influence on and alterations of the soil. Near-natural soils are at the beginning; first the terrestrial soils, and then the semi-terrestrial soils. Soil associations of anthropogenic aggradations and erosion are listed at the end. (Translator’s note: “aggradation” describes soils and materials which have been placed somewhere by natural processes (glaciers, water flows) or human actions. Anthropogenic aggradations include deep landfills (waste and debris depots, etc.), and shallow landfill of upper layers (playgrounds, building construction sites, street construction, etc.))

The borders were drawn between soil associations at ridges and sinks (relief). Neighboring units could then show the same beginning and ending points. The area delineation of soil associations also had to conform to the Berlin Digital Spatial Reference System based on block and block segment areas of homogeneous use. If this procedure would have led to great losses of information, particularly in non-built-up and loosely built-up areas such as forests, agricultural areas, and settled areas with low degrees of sealing, then these areas were further divided according to the borders of the soil associations. The decisive factors in these cases were the borders of geomorphological and geological units, contour lines, soil types (detail map), and aggradation borders. The factors for the delineation of anthric soil associations were area uses and the borders of aggradation (accumulation) or erosion.

Determining factors for soil development are parent substrate, prevailing soil type, relief (slope, sink, channel, gradient etc.), water and climate conditions, as well as the degree of human influence. Anthropogenic influences are characterized by aggradation of natural soil material and non-natural soil materials (war debris, construction debris, slag and cinders), and erosion of natural soil. Important measures for anthropogenic alterations in soil are present and previous use, and the degree of sealing. The map only shows unsealed soils, independent of the degree of sealing. The degree of sealing is used only as an aid for the evaluation of the degree of anthropogenic alterations of unsealed soils in this area.

Near-natural soil associations are characterized by typical soil types, geomorphological structures, substrate/soil types, and the influence of water. Alterations caused by humans are low.

The soil structure and soil associations of anthric soil associations are not influenced by the topographical relief but rather by type of use, as well as the occurrence and type of aggradations. Some transitional forms still retain the characteristics of parent substrate, geomorphology, groundwater levels, and some natural soils. This is the case at military training areas, former surface mining sites, cemeteries, and levelled sewage farms.

Table 4 gives results of human effects on soils. It orders the urban area into various soil association categories (anthric soil associations) under consideration of historic and current uses, damage to buildings in the Second World War, the type of construction, and the degree of sealing.

Tab. 4: Landscape Segments, Land Uses and Effects on Soils

The near-natural and anthric soil associations defined for West Berlin by Grenzius were transposed onto East Berlin with the aid of existing data bases, and analogical conclusions for comparable areas, such as geomorphology, use, water conditions, etc.. Problems occurred in areas where existing data bases did not enable clear classifications of soil associations based on analogical conclusions, or where combinations of uses and geomorphology appeared that were not considered or did not exist in West Berlin. Examples of these areas are plots once used for sewage farms, sinks in flat upland areas, and mapped podzolic soils of end morraines. Besides the soil associations applied in the Soil Association Map of West Berlin, the availability of appropriate mapping will be used to develop new soil associations. If there is insufficient information, then concept soil associations as well as collective soil associations will be developed. The soil associations used in the map have three different levels of differentiation and characterization:

1. Soil Associations (SA) – Soil associations in dependence on geomorphology and use. These can be verified by field studies in the form of detail maps, key profiles, and soil profile studies.
2. Collective Soil Associations (CSA) – These soil associations are collected because insufficient data material for East Berlin does not allow a differentiated categorization of individual soil associations.
3. Concept Soil Associations – are soil associations which do not exist or which have not yet been verified in West Berlin. They are a combination of use and geomorphology, such as levelled sewage farms. They have not yet been verified by soil studies.

Fig. 1: Classification of Soil Associations, Schematic Depiction of Procedure

The categorization of soil associations occurs in several processing steps:

1. The actual use of a given area was found in the land use file. Each type of use category has a special model pattern for categorization of soil associations (cf. Fig. 1).
2. Areas were defined as having mainly naturally developed soils or highly anthric soils (cf. Fig. 1). Land use and degree of sealing were used as criteria for the extent of anthropogenic alterations of soils. Other factors of determination were existing data material such as geological maps, cadastre of old contaminated sites, topographical maps of various ages, building damage maps, etc. (cf. Tab. 5).
3. Areas with hardly altered soils had no aggradations or erosion, and a degree of sealing of < 30%, or a degree of sealing of < 25% at new, large area construction areas. Soil associations here were categorized into near-natural soils according to the classification pattern in Table 6.
4. Areas with a degree of sealing of > 30%, or > 25% at large-area new constructions, were classified as highly anthric soil associations, depending on the type of use and the type of construction (cf. Tab. 5).

Tab. 5: Classification Guidelines for Soil Associations, in Dependence on Use Category and Degree of Sealing

The classification rules given in the figures and tables are to be seen as general rules. The precise classification of soil associations is frequently not possible due to lack of information about current land use or the degree of sealing. This means numerous special decisions have to be made for individual cases. The classification of soil associations in residential areas considered the construction type; the historical land use was also significant. Residential settlements on locations previously used by industry were evaluated as industrial areas, e.g., the Thälmannpark residential unit. The evaluation of waste disposal sites, military locations, sewage farms, and other landfills and aggradations was made based on information such as maps, the Cadastre of Old Contaminated Sites, aerial photography, and expert opinions, etc..

The determination of near-natural soil associations was made according to the procedure depicted in Table 6, if great anthropogenic soil alterations could be ruled out.

Tab. 6: Classification of Soil Associations of Natural Lithogenesis

Typical landscape segments with characteristic soil types, key profiles and the most important ecological properties exist for almost all soil associations.

The portrayal in the map gathered soil associations, concept soil associations, and collective soil associations into groups of uniform color. Geomorphic uniformity was decisive for the formation of near-natural soil association groups. Land use was decisive for the formation of anthric soil association groups. The color presentation of soil associations is oriented on the system of soil science mapping guidelines for soil types (Bodenkundliche Kartieranleitung). The color scheme was developed for soil types, but is used in the map for soil associations which are composed of several soil types with various properties. This meant a color scheme had to be developed which sometimes deviates from the model. This was done for the sake of a clear overview and readability.

The map at hand has a scale of 1 : 50,000 and is an overview map used by public planning agencies in determining goals and measures. Detailed statements about individual lots are not possible, for those kinds of statements require project-orientated detail maps.