The mapping of landslides susceptibility requires the aggregation of landscape characteristics that act differently in the process of landslides and may represents specificities of a region. In this context, the general objective of this study was to evaluate the Ordered Weighted Averaging (OWA) method in the mapping of landslide susceptibility. The method presupposes the integration of different characteristics of the landscape (factors), associating weights to them (named Importance Weights - IW). IW express the importance of these factors to the study. In the study, we used the factors: geological substrate, soil type, slope, land-use and land-cover, and precipitation. In the definition of factors and their weights, the Participatory Technique was used. In order to evaluate the OWA, two susceptibility maps were generated, calculating the decision making risk (R), and compensation level among factors (C). For the first one, only the IW and the total compensation among factors were considered (C = 100%) and for the other one, a second group of weights (the Order Weights (OW), that represents the influence of factors). Using the OW we obtain C = 72%. In the first map the medium level of susceptibility was predominant, by excessive influence of the slope factor (the most influent factor; with the highest IW). In the second map, by influence of OW, there was the aggregation of factors according to the importance predefined for them and the best distribution, in relation to the first one, of area between susceptibility levels. We conclude that OWA is adequate to mapping the landslide susceptibility and that the coherence between IW and OW is responsible to determine the robustness to the method.
Decision support; Weighted Linear Combination; Ordered Weighted Averaging
