¿Cómo encontrar NED 30 necesario para una delimitación de cuenca?

FaridAria

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Estoy intentando delimitar una cuenca en Washington DC y necesito NED 30 para ello. ¿Cómo puedo obtenerlo? Sé que se puede encontrar en National Map Viewer, pero cuando voy a la sección de descargas hay alrededor de 200 nombres de archivos y no puedo identificar cuál debo descargar.<\/P>

Gracias<\/P><\/BODY><\/HTML>

ChrisDonohue__GISP

I'm not an expert on DEM's and their downloads, but here's some ideas based on my likewise flailing around on my infrequent downloads of them:

An idea - there are several options in Download Data section of the National Map Viewer.  One is "Click here to draw and download based on a bounding box."  This could help limit your selection.

Also, I believe the 30 meter DEM's match the same extents of USGS 24K Topo Quads (though I could be off on this).  This may offer another way to determine which ones you need - there is a reference layer that can be displayed for the 24k Quads.

Then the crux issue - once you go to the Download function, it returns a long list of different files, making it difficult to figure out which one needs.  I believe for 30meter DEM's the files you want to download are just the ones listed as "1 arc-second" under the Resolution column. However, I'm not 100% sure on that - maybe someone who is more knowledgeable can chime in on that?

Hope this helps,

Chris Donohue, GISP