Maraga


Die Bodenkultur - Journal for Land Management, Food and Environment

F. Maraga, M. Arattano and S. Chersich:

Hydrological and sediment trends between 1982 and 2011 in the long term research basin Valle della Gallina, Italy

Summary

Sediment and hydrological monitoring were conducted in a small basin on the western Italian Alps along an experimental reach of 120 m located upstream of a sediment trap. A meteorological station located at the ridgeline and a monitoring station at the outlet have been recording hydrological and sediment flows since 1982. The mean subbasin discharge is 0.02 m3 s-1 (maximum: 6,4 m3 s-1, 1996) and flash floods occur with several peak flows higher than1 m3 s-1 . Sediment transport is mainly bed load with sediment discharges ranging between zero and 74 m3. Surface runoff and sediment transport have been decreasing since the year 2000, commensurate with reduced annual rainfall and increased soil water retention attributed to forest revegetation across the basin. There has been no land use or anthropogenic disturbance during the period of sediment monitoring.

Key words: Runoff decrease, water balance, coarse sediment transport.