Medium thermal conductivity Brandenburg

These maps are based on the legend units of the floor overview map (BÜK300) with corresponding allocation of parametrised surface soil shapes. These represent a soil form society for each legend unit. The individual surface soil forms (FBF) were documented with soil physical characteristics, which were determined by ground and laboratory tests. For this purpose, the characteristics of soil type dry raw density, total pore volume, water content at field capacity (FK) and permanent weld point (PWP), humus content were statistically derived for equal Horizon-Substrate combinations (HSK). Thermal conductivity (λ) determines the property of the soil, thermal energy by To transport conduction. It is the decisive parameter for the use of the soil as a heat source and storage and must be taken into account, among other things, in the application of near-surface geothermal energy (earth heat collectors) or in the construction of ground-mounted power cables. The pedotransfer function (PTF) according to Markert et al. (2017) used taking into account the above characteristics. This PTF is based on extensive measurements of thermal conductivity for a wide range of soils found in Brandenburg. For each HSK, the thermal conductivity for the water content at FK and PWP has been calculated up to a depth of 2 m. In the case of HSK in the area of influence of groundwater (Gr horizon), the thermal conductivity for full water saturation was estimated. Due to the parameterisation of PTFs for exclusively mineral soils, the following adjustments have been made: for organic HSK (gates), thermal conductivity of λFK = 0.4 W/m*K and λPWP = 0.2 W/m*K was calculated (see measurements by Markert et al. 2017; VKR 1.32 AG Soil 2010), for clay soils the parameters of clay soils have been used due to the low level of data, the humus content was taken into account by λhumos = λmineral — humus content*0.05. For HSK with anthropogenic starting rock, due to insufficient readings and missing information in the literature, no calculation of thermal conductivity was possible. In this case, the thermal conductivity per surface soil shape has been determined as a weighted harmonic means taking into account the thickness of all horizons. For better clarity and interpretability of the results, the weighted harmonic mean values of thermal conductivity were divided into the following 6 classes: Thermal conductivity [W/m*K] extremely low ≤ 0.4 very low 0.41-0.90 low 0.91-1,40 appropriation 1.41-1.90 high 1.91-2,40 very high 2,41-2,90 For the graphical representation as a map, the surface shapes with the same thermal conductivity class were grouped per legend unit (LE), whose area proportions according to Table 66 (AG Boden 2005) were added per LE and reported as an aggregated dominant, as well as an aggregate subdominant λ-FBF. For a few areas with a very heterogeneous composition of the surface soil forms, three λ-FBF are indicated.