Applied geomorphology. Theory and practice / Прикладная геоморфология. Теория и практика

This chapter discusses the influence of causal factors for landslide hazard mapping and stability of the prediction results. Among many quantitative models, we consider a model based on the theory of fuzzy sets with the algebraic sum operator. In the model, layers of geoscience maps represent the spatial information used for the prediction of areas in which the geomorphologic setting is similar to the ones in which a particular type of mass movement has taken place. One of the main challenges in the selection of these causal factors is that of how to compare two prediction models based on two different sets of casual factors. In the application discussed here, a study area in the Rio Chincina region of central Colombia is considered in which a spatial database was constructed for hazard mapping of ‘rapid debris avalanches*. In the database eleven map-layer causal factors were selected, and the landslides of rapid debris avalanches were divided into two subsequent periods. PRE-i960 (prior to I960) and POST-1960 (after 1960). For the prediction, the eleven layers of information were integrated as evidence toward a proposition that ‘points in the study area will be affected by future mass movement*. The analysis discussed here assesses the stability of the predicted hazard map with respect to the introduction or removal of each causal factor, i.e. of each map layer, according to the following steps. <...>