Analysis of land cover changes in the past and the future as contribution to landslide risk scenarios

摘要

Various factors influence the spatial and temporal pattern of landslide risk. Land cover change is one of the crucial factors influencing not only the natural process "landslide" and thus the hazard, but also the spatial distribution of elements at risk. Therefore the assessment of past and future landslide risk at regional scales implies the analysis of past and future land cover development. In this study, the first step in the analysis of landslide risk development over time is approached by analysing past land cover, as well as modelling potential future scenarios. The applied methods include analysis of orthophotographs and landcover scenario modelling with the Dyna-CLUE model. The timespan of the analysis covers 138 years from 1962 to 2100. The study area is located in Waidhofen/Ybbs (Austria) in the alpine foreland. A high number of landslides are recorded in the district. The predominant land cover types are grassland and forest. Buildings and residential areas are located in the valley bottoms and scattered on the hilltops. The results show clear changes in the land cover development of the past and in the future including spatial changes in the distribution of elements at risk. The trends show an increase in forest on the expense of grassland. The spatial evolution of the surfaces of arable land is rather high whereas the surfaces of residential zones increase steadily. The spatial analysis indicates also the development of new building areas and consequently potentially new landslide risk hotspots