wiki:Lakes

Version 8 (modified by celine, 15 years ago) (diff)

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Pour les lacs, dans la couche lacs upstream_a correspond à cont_pixel du riversegments aval dans la couche riversegments . #63

How to join the lakes with the riversegments layer

Differents "types" of lakes :
source:data/Docs/trac/Lakes/Lakes4.jpg
Lake 1 : upstream_a=350 = cont_pixel du riversegement 1
Lake 2 : uptream_a=60826=cont_pixel du riversegment 2 (and pfafstette lake2 = pfafstette riversegment2)
Lake 3 : upstream_a=0 (but several cont_pixel=0 in riversegments table)
Same wso_id for the lakes 1, 2, 3 and same wso_id for the five riversegment (they are in the same bassin)

  • Some are on the same river segement --> one cont_pixel in riversegments = one upstream_a
  • Some cross different river segements --> severals cont_pixel = one upstream_a
  • Some are not on a river segement
source:data/Docs/trac/Lakes/Lakes3.jpgsource:data/Docs/trac/Lakes/Lakes1.jpgsource:data/Docs/trac/Lakes/Lakes2.jpg

The "shape_area" variable is more accurate than "area" variable, same as "shape_leng" and "perimeter"