## 2 Materials and Methods
### Modelling
#### 2.2.2 \(K\) Factor  
CZ: For the Czech Republic, the spatially most detailed soil map is a soil bony map (scale 1:5000) developed since the 1960s and continuously updated, since the map is a basis for the state land tax policy of agricultural land. The map is officially distributed by the State Land Office, and basic soil physical properties are allocated to each bony unit. For official erosion modelling (cross compliance, land consolidation projects, etc. ), a transfer scheme to derive \(K\) factor information from the national bony map was developed [28]. The lookup table used in this transfer scheme is published in the official CZ USLE methodology [29]. BY: In general, the Bavarian administration calculates the \(K\) factor following the German Industry Standard DIN 19708 [13], which uses an equation system [30; 31] accounting for the full range of the original \(K\) factor nomograph as given in [PERSON] et al. [32] and Wischmeier and Smith [16]. The transferability of the original \(K\) factors developed for US soils to German soil conditions was extensively tested by [PERSON] et al. (1987), concluding that the US \(K\) factors are well applicable for German soils. However, for pragmatic reasons and due to the challenges to provide all necessary soil input data, the German soil bony map (scale: 1:25,000, for details see Table 2) available for all arable land in Germany is used together with a lookup-table provided in the Industry Standard (DIN 2017). This map provides soil texture as well as information regarding soil genesis and general soil status for agricultural use, all three parameters are used to derive \(K\) factor values. The relation between the soil bony map units and the \(K\) factors were originally established by [PERSON] et al. (1987) comparing calculated \(K\) factors with map units. \begin{table}
\begin{tabular}{c c c c} \hline
**USLE Factors** & **Officially Use Dataset (Standard)** & **Data Source to Derive Officially Used Dataset** & **Data Provider (Web-Site)** \\ \hline \multicolumn{4}{c}{**Test catchment CZ**} \\ \hline R & Adopted from state accepted map & 1 min resolution precipitation data for meteorological & \begin{tabular}{c} Czech Hydrometeorological Institute \\ stations (period of recent 10 years) \\ \end{tabular}  & \begin{tabular}{c} ([[http://portal.l.m.cz/1-zen](http://portal.l.m.cz/1-zen)]([http://portal.l.m.cz/1-zen](http://portal.l.m.cz/1-zen))) \\ \end{tabular}  \\ \(K\) & Adopted by direct conversion & Sol poultry map of \(CZ\) & \begin{tabular}{c} State Land Office ([[https://www.sporc.cz/](https://www.sporc.cz/)]([https://www.sporc.cz/](https://www.sporc.cz/))) \\ \end{tabular}  \\ \(LS\) (DEM) & Calculated according to description in methods & \(5\times 5\) m\({}^{2}\) based on LIDAR DEM & \begin{tabular}{c} ([[https://www.cavic.cz/](https://www.cavic.cz/)]([https://www.cavic.cz/](https://www.cavic.cz/))) \\ \end{tabular}  \\ \(LS\) (Land use) & Calculated according to description in methods & \begin{tabular}{c} LPS parcel data set \\ ([[http://aagric.cz/public/vweb/en/mze](http://aagric.cz/public/vweb/en/mze)]([http://aagric.cz/public/vweb/en/mze](http://aagric.cz/public/vweb/en/mze))) \\ \end{tabular}  & \begin{tabular}{c} Ministry of Agriculture \\ ([[http://aagric.cz/public/vweb/en/mze](http://aagric.cz/public/vweb/en/mze)]([http://aagric.cz/public/vweb/en/mze](http://aagric.cz/public/vweb/en/mze))) \\ \end{tabular}  \\ \(C\) & Official tool used & Average crop rotation for 2016 & \begin{tabular}{c} Czech Statistical Institute \\ \end{tabular}  \\ \(P\) & & Standard for arable land 1.0 & \\ \hline \multicolumn{4}{c}{**Test catchment BY**} \\ \hline R & Map of long-term mean \(R\) factors (1981–2010) for each municipality & Long-term annual precipitation (1981–2010) in 1 x & \ \begin{tabular}{c} German weather service \\ ([[https://opendata.dwd.doz/climate](https://opendata.dwd.doz/climate)]([https://opendata.dwd.doz/climate](https://opendata.dwd.doz/climate)), environment) \\ \end{tabular}