Jump to content

 
Photo

flood maps

- - - - -

  • Please log in to reply
2 replies to this topic

#1
Luigi

Luigi

    Contributor

  • Validated Member
  • PipPip
  • 15 posts
  • Gender:Male
  • Location:Potsdam
  • No Country Selected

I have a DEM off a study area and I would like to make a flood map out of it...

I want to obtain all the cells that are below value X. So far so god.
My problem is that I only want to obtain "connected cells" this is, cells that are below the the value X and that are connected whit other cells of the same value (at least 4 more cells)

can anyone HELP?

I'm trying to build raster calculator expression :blink:

#2
gregory

gregory

    Key Contributor

  • Validated Member
  • PipPipPip
  • 96 posts
  • Gender:Male
  • Location:Cracow
  • Poland

the solution isn;t exaclly the way you asked for but should give the same result;
dissolve your raster by cell value,
then compute area for you new aggregated raster for each agregation you got
order in ascending way
there is some area of singel pixel - check whose of agregation are 4 and more.

#3
merft

merft

    Key Contributor

  • Validated Member
  • PipPipPip
  • 86 posts
  • Location:Colorado
  • United States

I would recommend using HEC-GeoRAS from the Army Corps of Engineers. There is a tutorial that explains how to use it. I believe it requires both Spatial and 3D Analyst to funtion. Good luck. -Tom




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users

-->