Filters and buffers for pollutants

The criterion “Filters and buffers for contaminants” is used for the evaluation of the soil sub-function “Compensating medium for material agents” and “Filters and buffers for pollutants” understands the ability of the soil to separate dissolved or suspended substances from their means of transport. The ability can be derived from mechanical or physico-chemical filter properties. Soils absorb substances with deposition from the air or directly by anthropogenic application, transfer them and store them primarily in the soil pores. Depending on the soil property, the storage or filter potential varies. The evaluation of the criterion “filters and buffers for pollutants” is carried out by assessing the potential cation exchange capacity and the air capacity of the soil up to the soil depth of the effective root space. The key data for this are: Soil type of fine soil, coarse soil proportions, rooting depth, air capacity, soil density and soil humus content. For the derivation, the horizontal and layer data of the guide profiles of the FIS soil are used. Soils with high slope inclination receive rating tees. The assessment does not directly assess the terrain position and climatic location conditions, although these are relevant for water storage capacity.