Climate hazards refer to "extreme phenomena and physical trends associated with climate or their physical impacts". They are seen as an external climatic signal with significant impacts on human life, and more specifically on soil degradation. The document "Evaluation of water erosion by the aggregation method", takes stock of water erosion study techniques and proposes a new qualitative erosion estimation method. The method complements the concept of erodibility to climate change. It is based on the Fifth Assessment Report (AR5) of the IPCC Working Group II (WGII). The method is evaluated according to four sub-methods: the structure of an impact chain of erodibility factors, the min-max method, the aggregation method, remote sensing and GIS mapping of actual erosion forms and processes. The method is based on a practical evaluation study in the Nariarlé sub-watershed, Nakanbé basin, Burkina Faso.