Changes in land cover and shallow landslide activity: a case study in the Spanish Pyrenees

11 Pag., 3 Tabl., 4 Fig. The definitive version is available at: http://www.sciencedirect.com/science/journal/0169555XThe Pyrenees, like many other mountain areas in Europe, have experienced depopulation and land abandonment during the 20th century. This has encouraged vegetation recovery in formerly occupied areas, including reforestation to promote woodland. The objective of this study is to analyse the effects of these changes on shallow landsliding, a process responsible for erosion and land degradation in many mountain areas. A sequence of aerial images reveals a slight decrease in the landslide occurrence rate in the last half of the 20th century and a parallel increase in the landslide extinction rate, i.e. the rate at which evidence of landslide activity is removed by vegetation colonisation. A logistic regression routine was used to assess the influence of land use and vegetation recovery in the occurrence of shallow landslides. The result shows that the former arable fields on the valley slopes still facilitate landsliding, even after land abandonment and revegetation by shrubs or trees. A shift in the topographic location of landslides was also detected, pointing to an increased importance of water redistribution in the slopes after prolonged rainfall periods.This study has been supported by the research projects PIRIHEROS (REN2003-08678/HID) and CANOA (CGL2004-04919-C02-01), funded by CICYT (Spanish Ministry of Science and Technology), and by RESEL (Spanish Ministry of Environment). Parts of the data used were collected with the support of the DAMOCLES project (EVG1-1999-00027P), funded by the European Commission. Personal support was provided by a post-doctoral grant funded by the Spanish Government Secretary for Education and Universities and the European Social Fund.Peer reviewe