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To characterize channel-network morphodynamics and response potential in the Gadria-Strimm basin (14.8 km^2) we conduct a concerted effort entailing: (i) high-resolution mapping of landforms, channel reaches, and sediment sources; and (ii) historical evolution of colluvial channel disturbance through sequential aerial photosets (1945-59-69-82-90-00-06-11). The mapping was carried out via stereographic inspection of aerial photographs, examination of 2.5-m gridded DTM and DSM, and extensive field work. The study area is a formerly glaciated basin characterized by peculiar landform assemblages imposed by a combination of tectonic and glacial first-order structures. The most striking feature in Strimm Creek is a structurally-controlled valley step separating an upper hanging valley, dominated by periglacial and fluvial processes, and a V-notched lower part in which lateral colluvial channels are directly connected to Strimm’s main stem. In Gadria Creek, massive kame terraces located in proximity of the headwaters provide virtually unlimited sediment supply to frequent debris-flow activity, making this sub-catchment an ideal site for monitoring, hence studying the mechanics of these processes. Preliminary results point to a high spatial variability of the colluvial channel network, in which sub-sectors have remained consistently active during the study period while others have become progressively dormant with notable forest re-growth. In an attempt to link sediment flux to topography and substrate type, future work will involve photogrammetric analysis across the sequential aerial photosets as well as a morphometric/geomechanical characterization of the surficial materials.

Debris flows are the most efficient processes of sediment transfer from slope base to alluvial fan terminus in mountain drainage basins. To advance current understanding of debris-flow sediment dynamics at the regional scale we analyze historical debris-flow events in 82 basins of the Alto Adige Province, north-eastern Italy. By combining historical information on event-based debris-flow volumetric deposition and high-resolution (LiDARderived) digital topography we (i) identify seasonal trends in debris-flow activity; (ii) characterize the principal topographic conditions at which debris-flow initiation, transportation, and deposition occur; (iii) detail debris-flow sediment transfer at the basin and the regional scales; and (iv) identify lithologic dependences on debris-flow activity. For the first time, we show that basin-wide specific sediment yield describes a negative scaling relation with basin area, which in turn, is modulated by dominant bedrock geology and chiefly by the abundance of glacial and paraglacial surficial materials.

We present a new rock glacier inventory compiled for the Orobic Alps (2000 sqkm) and the Livigno Valley (270 sqkm), Lombardy Region, Italy. This effort is part of a larger ongoing project that aims at building a region-wide database of periglacial landforms. The two study areas represent the extremes, in terms of hydro-climatic and physiographic characteristics, within the spectrum of alpine terrain variability in Lombardy. The inventory of the two study areas has been conducted by combining a number of remotely-sensed images with field traverses. Specifically, the interpretation of high-resolution (0,5 x 0,5 m) digital aerial photos flown in 2000, 2003 and 2007 in conjunction with a 2-m DSM (Digital Surface Model), allowed identifying and mapping 416 and 108 rock glaciers in the Orobic Alps and in the Livigno Valley respectively. Measurements and photographs taken during fieldwork provided critical ground control for the validation of data extracted from remotely-based analysis. Attributes for each rock glacier include type (talus-lobate, talus-tongue shaped, debris-lobate, debristongue shaped, and protalus rampart), activity (active/inactive, or relict), minimum and maximum elevation, aspect, slope, geographic location, area, and dominant lithology. Preliminary results sh ow that in both study areas rock glaciers are quite uniformly distributed, with lower spatial densities in the most heavily glacierized areas. This pattern seems to reflect the geomorphological classification between glacial and periglacial environments. In the Orobic Alps, 388 (93%) rock glaciers were classified as relict while only 23 (21%) in Livigno Valley with 75 (89%) active or inactive. The most common rock glacier type in both areas are protalus ramparts (59% in the Orobic Alps and 36% in the Livigno Valley) followed by talus lobate rock glaciers (35% in the former and 32% in the latter). The active/inactive rock glacier’s minimum elevation, often considered discontinuous permafrost’s lower limit, is set a 2747 m a.s.l. in the Livigno Valley and 2386 m a.s.l. in the Orobic Alps. In both study areas, rock glaciers sit at similar slopes (chiefly around 20-25_), face predominantly north sectors, and are composed by metamorphic debris, in agreement with local dominant lithologies. The identification and classification of rock glaciers in Lombardy will form the basis to draft a preliminary regionwide mapping of discontinuous permafrost potential; hence, test and refine available physically-based models of permafrost spatial distribution.

We present a new rock glacier inventory compiled for the Orobic Alps (2000 sqkm) and the Livigno Valley (270 sqkm), Lombardy Region, Italy. This effort is part of a larger ongoing project that aims at building a region-wide database of periglacial landforms. The two study areas represent the extremes, in terms of hydro-climatic and physiographic characteristics, within the spectrum of alpine terrain variability in Lombardy. The inventory of the two study areas has been conducted by combining a number of remotely-sensed images with field traverses. Specifically, the interpretation of high-resolution (0,5 x 0,5 m) digital aerial photos flown in 2000, 2003 and 2007 in conjunction with a 2-m DSM (Digital Surface Model), allowed identifying and mapping 416 and 108 rock glaciers in the Orobic Alps and in the Livigno Valley respectively. Measurements and photographs taken during fieldwork provided critical ground control for the validation of data extracted from remotely-based analysis. Attributes for each rock glacier include type (talus-lobate, talus-tongue shaped, debris-lobate, debristongue shaped, and protalus rampart), activity (active/inactive, or relict), minimum and maximum elevation, aspect, slope, geographic location, area, and dominant lithology. Preliminary results sh ow that in both study areas rock glaciers are quite uniformly distributed, with lower spatial densities in the most heavily glacierized areas. This pattern seems to reflect the geomorphological classification between glacial and periglacial environments. In the Orobic Alps, 388 (93%) rock glaciers were classified as relict while only 23 (21%) in Livigno Valley with 75 (89%) active or inactive. The most common rock glacier type in both areas are protalus ramparts (59% in the Orobic Alps and 36% in the Livigno Valley) followed by talus lobate rock glaciers (35% in the former and 32% in the latter). The active/inactive rock glacier’s minimum elevation, often considered discontinuous permafrost’s lower limit, is set a 2747 m a.s.l. in the Livigno Valley and 2386 m a.s.l. in the Orobic Alps. In both study areas, rock glaciers sit at similar slopes (chiefly around 20-25_), face predominantly north sectors, and are composed by metamorphic debris, in agreement with local dominant lithologies. The identification and classification of rock glaciers in Lombardy will form the basis to draft a preliminary regionwide mapping of discontinuous permafrost potential; hence, test and refine available physically-based models of permafrost spatial distribution.