Today, a number of quantitative models to assess soil erosion risks and factors influencing soil erosion risk is available. However, these models are developed for the temperate zones in Northern America and Europe and would need adaptation to the conditions of the subtropical Gina River catchment. Additionally, most of the modelling approaches concentrate on a limited number of factors. Thus, these can always reflect only a partial aspect of reality.

As there is no soil erosion risk modelling approach for tropical regions available at the present two approaches to estimate soil erosion risk are developed for the Gina River catchment (see figure):

• A semi-quantitative approach: is based on a qualitative weighting of numerically scaled data.
• A qualitative approach: is based on qualitative weighting of the landscape factors (Beck et al. 2004).

Both are presented in the following.