Author:

Keywords:

Mass movement; sediment export; seismicity; water erosion, Science & Technology, Physical Sciences, Geography, Physical, Geosciences, Multidisciplinary, Physical Geography, Geology, Mass movement, Sediment export, Seismicity, Lithology, Topography, Water erosion, EARTHQUAKE-INDUCED LANDSLIDES, PREDICTING SOIL-EROSION, SEISMIC ACTIVITY, MOUNTAIN BELT, PLOT DATA, CATCHMENT, EUROPE, CONNECTIVITY, CLIMATE, MODELS, 0403 Geology, 0406 Physical Geography and Environmental Geoscience, Geography, 3705 Geology, 3709 Physical geography and environmental geoscience, 4104 Environmental management

Abstract:

It is generally accepted that catchment sediment yield (SY, t km−2 y−1) can be strongly influenced by landsliding. Nevertheless, due to data requirements, only fewstudies investigated this effect at a regional scale. The objective of this study is therefore to explore the potential of a landslide susceptibility map for explaining the spatial variation of SY in Romania.We selected 133 catchments in Romania for which SYwas measured during a period of at least 10 years. For each catchment, we derived a variety of proxies that potentially explain SY, including several indicators of landslide occurrence. The latterwere derived froma published landslide susceptibility map. Results showthat SY is significantly correlatedwith mean landslide susceptibility (r2=0.30). Estimates of average sheet and rill erosion rates showed a much weaker correlation with SY (r2 = 0.06). Further analyses showed that the strong correlation between SY and landslide susceptibility is mainly attributed to regional variations in lithology and seismicity. Especially the latter may play a crucial role in understanding denudation rates at regional scales, e.g. by facilitating the occurrence of landslides. Using landslide proxies that also account for sediment connectivity did not result in stronger correlations. Overall, our results show that landslide susceptibility maps can be a highly useful tool to predict SY at regional scales, provided that they incorporate all relevant factors.