River remote sensing for setting-up quantitative hydromorphological rehabilitation targets — ASN Events

River remote sensing for setting-up quantitative hydromorphological rehabilitation targets (#34)

Simone Bizzi 1 , Luca Demarchi 1
  1. JRC, Ispra, ITALY, Italy


River classification and the derived knowledge about river systems have so far been based on discontinuous sampling along the river course through field works and/or (subjective) interpretation of aerial images. Remote sensing data, since some years, offer notable opportunities to change this paradigm enriching traditional information with an unprecedented amount of spatially distributed hydromorphological data.  A river characterization framework based on color infrared orthophotos at 40 cm and a LIDAR derived DTM at 5 m acquired simultaneously in 2009-2010 have allowed to characterize the main river systems in the Piedmont Region Italy (25400 kmq) with continuous information on areal and topographic hydromorphological features. The framework by a semi-automated procedure delineates the valley bottom of each river course and within this the active channel area composed of water channels, unvegetated and vegeted sediment bars, and, if present, islands. Using semi-automated segmentations of river courses and statistical analyses of the derived regional database river functional types have been quantitatively defined in terms of distribution of areal and topographic features. Reference types have been identified within all the functional types defined. Rehabilitation targets can then be defined for hydromorphologically altered river segments, each of which can be associated to a specific reference functional type based on case specific evaluations.  In case of restoration projects the achievements of these targets can be monitored through planned acquisition campaigns of RS data in order to measure river morphodynamic trajectories over years and so assess the rate of success of the implemented measures.

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