Hydrological and sedimentary processes related to a high intensity debris-flow catchment in the Dolomites (Italian Alps)
Active alpine alluvial fans are often dominated by massive and sometimes catastrophic deposition processes which are commonly defined as debris flow events. As a first aim, this work proposes the study of the sedimentary processes compared with the sedimentary record of the Acquabona basin, located in the Dolomites, Eastern Italian Alps. This comparison allows us to better analyze and understand the role that such debris flow events have in building up the valley slope and reshaping its surface. Typically primary sedimentary processes are characterized by debris or mud flow deposition and subordinated flood events dominated by debris-poor water flow. The Acquabona catchment is a natural laboratory for typical Dolomites scree slope because of an exceptional high frequency of debris flow events. These have been monitored since 1997 yielding a good sequence of events stage data and related rainfall. Video recordings during some events are also available providing documentary evidence of debris transport, flow rheology and sedimentation during those events along the main channel. Facies analysis and sedimentological investigation of the Acquabona deposits have been carried out within this work in order to determine sediment distribution and define the main sedimentary processes responsible for the sediment transport and deposition in the catchment. Utilizing the long series of recorded stage data, different hydrographs features have also been analyzed and compared with related sedimentary processes. The study of modern deposits and stratigraphical record indicates that magnitude and dynamic characteristics of the main sedimentary processes did not change over the recent geological time. However, aggradation rate, frequency of events and areas of main erosion and deposition can change in the future. This would require continuous efforts to monitor the fan and sustained activity maintenance activity aimed to remove the freshly accumulated material from the bypass channel and the deposition basin.
sedimentology stratigraphy debris flow Dolomites
A. Moscariello A.M. Deganutti
Delft University of Technology, Department of Geotechnology Delft, The Netherlands; and Godwin Insti CNR-IRPI, Institute for Prevention of Hydro-Geological Hazards, National Research Council of Italy,P
国际会议
成都
英文
165-175
2007-05-17(万方平台首次上网日期,不代表论文的发表时间)