From the Analyze tab on your Ribbon select Catchments and then select Catchment Area,
Specify the Catchment properties you would like prior to creating any catchment objects.
From the same Catchment drop down select Create Catchment Group and then provide a Name.
From the Catchment drop down one more time, select "Create catchment from surface".
Select a discharge point on your surface and the catchment creation dialog box will appear.
Provide a Name, Surface and Drainage Structure (optional), and Runoff Coefficient and then select OK
After click OK you will return to your drawing and the Catchment area boundary and flow path will have been created along with the labels for both. If you haven't done so yet, take the time to setup some catchment object and label styles so that it presents properly.
After completing the creation of your Catchment area, select it and then select "Catchment Properties".
On the Catchment Area Properties tab you will be able to obtain all the relevant information regarding your catchment area.
All Catchment Objects created will now be accessible from your Toolspace under the new "Catchments" category. I hope this sheds some light on this new tool. Have fun using it. Thanks.
have surface from google earth after create the catchment it take small part what is problem by then,and how to get large catchment instead of small catchment,and what is guide of pick discharge points,help please am use 3d 2012 civil.
ReplyDeleteAs far as I know, the tool doesn't have the smarts to aggregate small areas into large ones. It's not much better than the tools in Autodesk LDD 14 years ago. If you want nice catchment areas as shown in the examples you find online, you have to work extensively on your surface to eliminate every jagged point and hint of roughness. In other words, it is not useful for delineating surveys of existing terrain with unknown drainage patterns. Unfortunately, that is the only case in which its use makes sense. (We should already know the drainage pattern of the proposed grading we create!) Therefore, the tool is generally useless.
ReplyDeleteYou can do this in ArcGIS with Spatial Analyst and 3D Analyst extensions, but it's about a 10-step process. It's only valuable for large or complex sites.
Unfortunately, it's still quite common to find that doing it by eye is much faster than using the electronic tools available. It looks like the future isn't here yet. Probably a good thing ... more jobs for us to do.