Morphologically active reaches of the Vésubie River catchment during Storm Alex (Oct. 2020)

Résumé 0

This archive gather a shapefile of polygons delineating 100-m-long river reaches of the Vésubie catchment. The polygon limits delineate the morphologically actives areas based on the difference of digitial elevation model (DTM) before and after the flood (including a coregistration of both DTM). Only reaches with consistent geomorphic activity (erosion or deposition) are included. Canopy height model (CHM) were computed in each of these polygons based on LiDAR 3D point clouds. The EPSG (reference system) is 2154 (RGF93 v1 / Lambert-93). To each polygon is attached the following metadata: ID: identification number of each tributary (1-43) and main branches (44-47) ordered by increasing drainage area; ID_reach: identification number of the reach. It is composed by the identification number of the specific (sub-)catchment (ID), followed by an progressive number; Channel: name of the (sub-)catchment/channel; Reach_d: It is composed by the name of of the specific (sub-)catchment/channel (Channel), followed by an progressive number consistent with ID_reach; System: defines the reference valley bottom stretch of each tributary; Srfc_m2 (Surface_m2): is the surface (m2) of the reach; Lngth_m (Length_m): is the longitudinal length (m) of the reach along the channel; (menan_slopr%): is he mean channel gradient computed as the difference in elevation between the upstream and the downstream end of the channel, divided by the length of the reach (Lngth_m); Drn_S_2 (Drainage_Surface_m2): is the maximum value of drainage area at reach; Depo_Vl (Depo_vol): is the sediment volume deposited inside the reach; Eros_Vl (Eros_vol): is the sediment volume eroded inside the reach; Net_Vol: is the sediment net budget of the reach; CHM2018: extension (m2) of the 2018 forest cover that was inside the reach; CHM2020: extension (m2) of the 2020 forest cover that was inside the reach; Diff_CHM: extension difference of forest cover (m2) inside the reach between 2018 and 2020. It is computed as CHM2020-CHM2018