In Caracas, Venezuela, landslides have become an increasing problem frequently associated with the rainy season and the creation of more vulnerable areas by the urbanization process. Their effects have been particularly evident in the squatter settlements or barrios in the hillsides surrounding Caracas. The purpose of this research is to examine the incidence of slope failure in the barrios. An account of the urban growth of Caracas is given in order to illustrate how population has been progressively occupying the valley and its hillsides. A data set of 205 slope failures which occurred over a six year period is set up. The slope failures in the Metropolitan Area are analyzed both spatially and over time in order to elucidate some of the factors responsible for their incidence. Besides location and date of occurrence, the data set incorporates rainfall seasonality and cumulative totals, lithology, slope angle, type of mass movement, and location within the urban context. The role of the rainfall as a triggering factor for the slope failures is examined. Cumulative rainfall values are considered for 10, 30 days and seasonally. With the help of a sequence of aerial photographs, the evolution of slope failure in barrio El Cipres is used to examine the links between the settlement process and the evolution of the local geomorphology. A Landslide Susceptibility Map is then produced.
The research shows that rainfall plays an important role in the incidence of slope failures, but its influence in barrios is also compounded by other factors such as enhanced infiltration and the changes in slope produced by the settlements process. In this connection improvements in services and the consolidation of the barrio may add to the problem if they are not carefully planned
