Landslide inventory of the Crasna catchment, Moldavian Plateau, Romania

Spatial landslide inventories are fundamental elements for landslide spatial susceptibility and landslide hazard modelling. These are digital spatial databases which indicate the spatial presence and the spatial extent of the landslide events or complexes. In the present study we describe the creation and the statistical validation of a landslide inventory for the Crasna catchment, left tributary of the Bârlad river, Moldavian Plateau. In this catchment, with an area of 185.2 km2, 1619 polygons were delineated, representing landslides which have a clear and distinct morphological signature on high resolution DEMs. Beside the DEMs, high resolution imagery from the Google Earth and Bing Maps archives and old and recent aerial images were used to supplement the morphological information. The obtained inventory is a geomorphological one and a historical one because it contains all the landslides, relict, old and recent, that are recognizable in the actual geomorphological context. The criteria for landslide delineation was mainly the morphological one, respectively the presence of any of the following landslide elements: principal and secondary scarps, landslide body with rough topography, bedding traces, landslide foot, tip, toe and flanks. Beside the landslide delineation, the landslide inventory contains data about the typology of the landslide (using the Cruden, Varnes & Hungr classifications), inferred from the morphology, the landslide age inferred from the geomorphological and topological information of the remote sensing data. The validity of the inventory was tested and argued using the Malamud et al., 2004 landslide area distribution frequency. This shows that the magnitudes of the landslides from the Lohan catchment are distributed in a similar way as landslide magnitude is distributed in other areas of the globe. Keywords— landslide inventory; Crasna catchment; Moldavian Plateau