= GIS Structures =

Three candidates are available for EDA

When comparing surface layers for ECRINs and CCM for the bassin Loire-Bretagne : the CCM layer is more extended than the Ecrin Layer

[[Image(source:EDA/data/Docs/trac/Loire Bretagne 1 - CCM Ecrins.jpg)]]

== describing the CCM layers ==

gid::
  id (corresponds to line number)
wso1_id::
  id of the primary catchment drained by the river segment.
wso_id::
  id of the Sea-outlet to which the river segment belongs.
rvr_id::
 reference of the name of the river to which the segment belongs (often 0)
fromnode::
 upstream node 
tonode::
 downstream node
strahler::
 the stream order hierarchy, the sizes range from a first order stream to the largest a 11th order stream
pfafstette::
 Pfafstetter code (?) of the river segment and its primary catchment
nextdownid::
 next segment identifyer downstream points to wso_id
longpath::
 identifies wether the river segment is part of the longest flow path in the River Basin (sea-outlet), Y(es) or NULL
maindrain_::
 ?
maindrain1::
 ?
length::
 length of a river segment in meters
cum_len::
 cumulated length of the upstream flow network, including the river segment itself (longest route ?)-in meters
pixels_100::
 area directly drained by the river segment (area of the primary catchment), in 100m*100m grid-cells
catchment_::
 ?
cont_pixel::
 area upstream of the From Node drained by the river segment in 100m*100m grid-cells
drain_km2::
 full area drained by the river segment and upstream area - in square kilometres
alt_gradie::
 relief Energy of the river segment : ((Elevation at From Node-Elevation at ToNode)/Segment Length)*100 in per cent
burned::
 percentage grid-cells of the river segment having a high confidence level with respect to its geographical position   confidence::
 percentage of grid-cells of the river segment having a high confidence level with respect to its geographical position
window::
 here 2003
shape_leng::
 ?
the_geom::
 the_geom 

[Image(source:"EDA/data/Docs/trac/Comparaison CCM-Ecrins-BDCarthage.jpg")]