nav[aria-label="Primary Navigation"] { padding: 0; & ul { list-style: none; width: 100%; display: flex; flex-direction: row; justify-content: start; align-items: start; gap: 30px; padding: 0; & li { margin: 0; } & ul li { list-style: none; } } }

Délimitation du bassin versant - Plusieurs ponceaux

AliMcLeod

ArcGIS Pro 2.6

Bonjour à tous - Je suis bloqué avec la délimitation d'un bassin versant. J'ai téléchargé la boîte à outils archydro et je l'utilise autant que possible au lieu de spatial analyst. J'ai environ 40 ponceaux le long d'une route de 15 miles qui ont été 'brûlés' dans un MNT. Je les ai ajustés au lien de cours d'eau, et j'ai vérifié que tous les cours d'eau traversaient la route/étaient proches des ponceaux avant de créer le streamlink (nombre de cellules défini à 1500). Le bassin versant, le bassin adjoint, la ligne de drainage et les points de drainage semblent tous corrects.

Lorsque j'utilise Point Delineator, il choisit un seul point de ponceau et délimite un tout petit sous-bassin versant (encore plus petit que le polygone du bassin). Lorsque j'utilise Watershed Delineation, il passe simplement en boucle entre "droping id" à "processed 0 features" à "final selection" à "sampling" à "100%" puis revient. Il ne se termine jamais, et cela tourne depuis plus de trois heures sans résultat.

Quelqu'un connaît-il une solution pour que je puisse obtenir un bassin versant complet, incluant la majorité des bassins, mais au moins le cours d'eau principal ? Dois-je définir une taille de cellule plus grande pour un nouveau streamlink puis délimiter le bassin versant à partir de ce cours d'eau ? Je dois juste m'assurer que tout le flux possible entre dans les ponceaux, et je ne veux pas limiter la zone potentielle en créant une ligne de cours d'eau trop grande.

Trouver plus de publications taguées avec

Water Resources

Arc Hydro

Accepted answers

All comments

AliMcLeod

After digging even deeper into the data, I may have discovered the problem. For some reason, my stream and stream links are not connecting the paths together- and when I turn on the drainage line layer- that feature class is just line data of these two rasters overlapping.

So how do i get one solid stream network to appear, and not have the mainstream itself become disconnected? (Str was a cell size of 500, Str2 was 1000, Str3 was 1200, and Str4 was 1500; StrLnk was created from Str4)

AliMcLeod

in Pro the setup is slightly different....

but-- This is the zoomed out:

this is the zoomed in DEM:

So, this is why I am at an utter loss and confusion! I feel like all the steps I am taking SHOULD yield results. Yet, for some reason- I am coming up empty handed. And like you said earlier, if I am getting correct adjoint catchments, then the data is there and pulling appropriately.

The only issue I see here is the culverts- that the points themselves are causing a problem If the DEM is not a problem, the streams are not a problem, the catchments are not a problem. It has to be the culvert points. Snapped to the streams initially, or not and done during the watershed delineation, same lack of results.

MarkBoucher

I'm still in ArcMap, not Pro. With either version you should be able to symbolize the color ramp on the DEM to view the statistics "From Current Display Extent" (see first image). This allows you to see the subtle differences in the DEM no matter what your zoom level.

The second image below is a portion of our County DEM with this setting. The third image is a zoom in on what looks flat. The color ramp adjusts for the the data in that view revealing more detail.

You should be able to study parts of your DEM to tell if burning the streams is needed, especially where you are getting the small watersheds.

Of course, make sure the right rasters are being used by the delineation tool.

Portion of our County DEM

Zoomed in on the red square.

AliMcLeod

This is my 3m DEM--- but as you can see the northern portion of it is pretty flat. Mostly just creeks/wetlands with no major tributaries.

MarkBoucher

If the DEM has resolution to define the streams, you wouldn't have to burn the streams into the DEM. However, if the streams are not well defined by the DEM (the cell size is large enough to "bridge" the stream and on a color ramp of the DEM [or hillshade of the DEM] the streams are not clearly visible), you may need to burn in the streams.

AliMcLeod

Hi Mark--- yes that was the firs step after burning the DEM with the culverts.

Are you suggesting that I need to additionally burn the streams into the DEM as well?

MarkBoucher

Have you filled sinks? If not, that would be the step you need to do after burning streams and before flow direction.

Rejoindre la conversation

Les membres connectés peuvent publier, suivre les mises à jour, et plus encore. Nouveau ici ? Inscrivez-vous gratuitement.

Liens rapides

Community Help
Find useful guides, FAQs, and documents to help you navigate and make the most of Esri Community.