Sensitivity to ground shifts

The sensitivity map for landslides gives a first indication of the sensitivity to landslides at very local level in a study area located west of Brussels, in the south of the provinces of West Flanders, East Flanders and Flemish Brabant. At the base of the map lies a static model based on logistic regression for rare events. This procedure establishes the statistical link between the location of the rectified landslides (invented on site) and the possible control factors. The model was applied in a GIS environment for grids of 10 m to 10 m and predicts the likelihood of preventing a ground shift based on the slope gradient, the orientation of the slope (NW, W, ZW and Z), and the presence of certain litho-stratigraphic formations (the Ghent formation, member of Vlierzele and member of Merelbeke, the formation of Tielt and the formation of Kortrijk, member of Aalbeke). Initially, each grid was given a chance of preventing landslides. These probability values (between 0 and 1) were divided into 4 classes, resulting in pixels with low, moderate, high and very high sensitivity. Working with class boundaries in itself implies that two close values can be divided into a different class. The model was developed for the Flemish Ardennes, a sub-area of the study area, and then applied to the extensive area of study with the same geological and topographical characteristics.