## 1 Introduction  
Soil erosion, in the context of arable land use, is one of the major threats for global soils [1; 2] resulting in on-site and off-site damage [3]. On-site effects range from a reduction in crop yields [4; 5] to a decrease in soil organic carbon storage [6], while typical off-site effects are the eutrophication of inland waters [7] as well as silting of reservoirs [8].  
In the European Union, soil erosion is identified as one of the main environmental threats (see EU commission thematic strategy soil). It is addressed in a variety of rules and regulations associated with different soil and water protection targets, which are focused on-site soil conservation. The prevention of on-site damages has the main aim to fulfil the requirements of 'Good Agriculture and Environmental Condition' (GAEC) [9] as defined in the framework of the so-called Cross-Compliance [10], while the prevention of off-site damages mainly aims to reach the targets of the Water Framework Directive [11]. In this context, the interplay between a number of farming regulations and potential financial support provided to farmers via the EU (Cross-Compliance approach) is of tremendous importance as part of the Common Agricultural Policy (CAP). Within the EU legal framework, each country has a certain level of flexibility in the way grant payments to farmers are organized while taking national conditions into account. The same holds true for tools used to determine the effects of certain farming practices, e.g., for soil conservation. In the fields of erosion risk assessment, the used tools differ substantially between the EU countries or even between regions within countries. For example, in Germany, the federal state of Bavaria is using the German adaption of the Universal Soil Loss Equation (USLE) [12] which is the basis of a German Industry Standard [13], while the federal state of Savony is using the physically-based model EROSION3D [14]. In general, the USLE [15; 16] and the revised USLE (RUSLE; [17]) and its national and regional adaptions, partly resulting from specific data availability, are the most widely used tools for erosion risk assessment in Europe [18].  
Apart from the different national and regional adaptations of the USLE and/or RUSLE, there is a recent RUSLE-based European Soil Erosion Map [19], which used more generalized data available at a European level. This is supposed to allow for a regional comparison but is hardly applicable on the scale where soil conservation can be set into practice--the single parcel, or even specific parts of it. However, as no homogeneous soil erosion map or mapping technique was established at this level, which can be used to establish soil conservation strategies and allocate European or national/regional funds as incentives for farmers, one has to deal with potentially large differences in mathematical description/modelling approaches and model implementations of the same model (mostly the USLE and derivatives) in individual European countries or administrative units.  
The aim of this study is to use three different regional USLE-based approaches in three different test catchments in the Czech Republic, in Germany in the federal state of Bavaria (in the following referred to as Bavaria), and Austria, where nation-specific methods of soil loss calculations will be cross applied to (i) determine differences in modelled erosion due to the different model implementation, (ii) analyze and determine the most sensitive differences, and (iii) illustrate the difference between national USLE-based erosion risk maps and more generalized USLE-based European soil erosion risk map.