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catchment area

13 REPLIES 13
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Message 1 of 14
nostupidquestions
2718 Views, 13 Replies

catchment area

is the catchment area tool like the water drop tool except backwards? if i pick a point on my suface i would think it would give me the area that's flowing to it, like a watershed. it does this somewhat but it's not giving me what i think should be an acurate pline around the area. when i pick a point it should cover the whole side of a hill but it gives just a small area. i've picked a lot of places on the hill but the results are the same. i can't find any settings to maybe tweak the output.

Intel(R) Xeon(R) W-2245 CPU @ 3.90GHz 3.91 GHz
64 GB RAM
C3D 2023.2
13 REPLIES 13
Message 2 of 14

I'd look at the triangles of the surface to see if there are any flat spots that are causing the catchment tool to not make it up the hill. Maybe put a slope label on the triangle to see if it's flowing the correct direction towards the low point.

 

Christopher

Message 3 of 14

i'm sure there a bunch of flat spots. it's quite a large site and the contours are derived from contour polylines. i was hoping there was a setting somewhere. i'm trying to find the top of the basin that's draining to our road. i just used the waterdrop tool and defined the ridge that way. my computer isn't powerful enough to use the watershed surface display. thanks anyway.

Intel(R) Xeon(R) W-2245 CPU @ 3.90GHz 3.91 GHz
64 GB RAM
C3D 2023.2
Message 4 of 14

If you review the user assistance, it is recommended that you use the water drop together with the catchment area to define the overall area.  

Matthew Anderson, PE CFM
Product Manager
Autodesk (Innovyze)
Message 5 of 14

Turn on the flow arrows of your surface to review the catchments area; if your surface definition has any vaugaries in it the catchments will pick them up. As Matt mentioned the tool works in conjunction with the water drop.

Thank you

Joseph D. Bouza, P.E. (one of 'THOSE' People)

HP Z210 Workstation
Intel Xeon CPU E31240 @ 3.30 Hz
12 GB Ram


Note: Its all Resistentialism, so keep calm and carry on

64 Bit Win10 OS
Message 6 of 14
fcernst
in reply to: Matt.Anderson

"If you review the user assistance, it is recommended that you use the water drop together with the catchment area to define the overall area. " 

 

For years, this has been a tedious and very unelegant workflow suggestion. It is sophmoric and crude...

 

We need better basin analysis tools that think like an engineer and can see the drainage basin picture. We need surface drainage tools that allow the engineer to quickly achieve the level of basin discretization that the engineer is needing to achieve for the situation.

 

Usually this is aggregating the surface slivers these C3D surface routines typically produce for us, and expanding outward like the OP suggested.

 

Back to the drawing board for C3D programming...quickly get a surface algorithmist on this who understands what we have been frustrated with for years...



Fred Ernst, PE
C3D 2024
Ernst Engineering
www.ernstengineering.com
Message 7 of 14
asjanke
in reply to: fcernst

Agree with Fred Ernst,

Unfortunately this catchment tool serves limited to no purpose at this point. I see potential in the idea but as of yet it appears to be strictly unrealized.

IE - a catchment area may absolutely have an irregular surface, even for a catch basin which I assume the programmers may have had in mind with this option. There are absolutely times when flow goes over bumps and through pooled up areas that this program just stops at. The water drop tool is also very limited so suggesting that as a work around is not correct. Using it on anything but a perfectly engineered surface is almost useless, and even then fairly limited.
At this time Civil - 3d is not the correct tool to utilize for surface storm water analysis.

Lets define a catchment area: Area in which water will drain to a certain point.

This doesn't mean to the nearest mud puddle, the OP is looking for a option that anybody who works with storm water hopes will get there.

as of no, it appears GIS tools are the best route for these things at this time.

Aaron Janke, PE
U.P. Engineers & Architects, Inc.
www.upea.com
Message 8 of 14
tamtvd
in reply to: nostupidquestions

it's been 8 years, this question is still hot. All Civil Engineers need this function but Autodesk seems aiming to something else but this.

Autodesk please program this function. It'd be helpful to us much

Message 9 of 14
Joe-Bouza
in reply to: tamtvd

I agree it shouldn't be so poor. It is so much faster to go old school on catchments and simply draw them. You can convert hand drawn poly line into catchments and assign to inlet.  Now I'm not dealing with hundreds of acres either .

Thank you

Joseph D. Bouza, P.E. (one of 'THOSE' People)

HP Z210 Workstation
Intel Xeon CPU E31240 @ 3.30 Hz
12 GB Ram


Note: Its all Resistentialism, so keep calm and carry on

64 Bit Win10 OS
Message 10 of 14
ChrisRS
in reply to: tamtvd

You might want to look at defining watersheds in Infraworks (IWX). With regard to catchment areas , it appears that Autodesk has invested their time and resources in IWK rather that C3D.

 

I am not in favor of the Autodesk emphasis of INFRAWORKS over CIVIL 3D, but I accept it as the reality we face.  

Christopher Stevens
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Message 11 of 14
Matt.Anderson
in reply to: ChrisRS

With any method, the engineer needs to understand the assumptions and methods associated with the feature.

 

The Catchment in Civil 3D works on a TIN and is expecting a channel - a two-face channel to start working from.  It will always fall to a TIN corner.  Flat areas are a weakness - which is why a tiny incremental back-slope puddle along the flow path will interrupt the solution.   If you pushed inlets locations into a TIN - they appear as a point - not a 2 ft x 3 ft rectangle that violated the two-face channel to start with.  This makes identifying true sag near impossible without using LINEWORKSHRINKWRAP against multiple returned catchments.  Water is infinitely thin in the assumptions underlying this method -  leading to a precision that is entirely unnecessary.   

 

The value proposition for GIS-based solutions, like what is provided in InfraWorks, is they rely on a gridded approach with significantly fewer precision to the infinite thinness.  These methods assume infinitely think water by filling sinks so that water always has a path across the surface downslope.  In the case of InfraWorks, a simple D8 solution is provided - however - you have little control of the other steps possible steps in the process.   The flow path is simplified to the grid resolution and is the accumulation of the overall drainage cell count above it.  Its a simplification and automation of TauDEM.   

 

In both cases - hydro-enforcing the data is required.  A culvert or inlets or bridges need special processing.

 

The St. Venat Shallow Water Equations provides the best approach.   Innovyze InfoWorks ICM, or XPSWMM, or Tuflow HPC should help as the analysis is rain-on-surface with infiltration, mannings roughness being taken into account.   Eliminates the need for hydro-enforcing - and watershed polygons as well.

Matthew Anderson, PE CFM
Product Manager
Autodesk (Innovyze)
Message 12 of 14
Joe-Bouza
in reply to: Matt.Anderson

Wow. What did we do in the olden days of reading contours and planimeters 😳

Thank you

Joseph D. Bouza, P.E. (one of 'THOSE' People)

HP Z210 Workstation
Intel Xeon CPU E31240 @ 3.30 Hz
12 GB Ram


Note: Its all Resistentialism, so keep calm and carry on

64 Bit Win10 OS
Message 13 of 14
ChrisRS
in reply to: Matt.Anderson

Thanks, @Matt.Anderson. I am not familiar with your products, and currently work on mostly very small projects. Your insights on the C3D and IWX methodologist is useful. I had never researched that.

 

This thread is nearly 8 years old. There does not seem to have been any improvement to C3D catchment capabilities in that time. Autodesk seems to be trying again with IWK. It would be nice if there was some clarity on the part of ADREK as to their goal for catchment/watershed tools in their products. I will not hold my breath.

 

Catchments did not work well in 2011. If catchments are to remain a feature C3D, they should work better in 2019 than they did in 2011. (I do not see that as being the case.)

 

To a large extent, I am expect the ADESK catchment/watershed feature be a "Black Box" that just works. I can verify the results by comparing to the contours. I do not propose to tell ADESK how to be programmers. This is a part of Civil 3D, is not a bonus tool that we understand to be still under development.

 

Come on ADESK, the product is Civil 3D, not Civil 1½D. Features should be complete, not half done; work reliably all of the time, not half of the time; and be fast, not half fast. Smiley Wink     

Christopher Stevens
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Message 14 of 14
Matt.Anderson
in reply to: ChrisRS

@ChrisRS - 'work better' in 8 years?  The Catchment "area" or the "Catchment Object".  The Catchment [Object] took a simple concept [Catchment Area was pre-2011] and developed it over three years to tie it to the Hydraflow export.  [Area / TR55 Longest Flow Path & Time of Concentration / Coefficient of Runoff]  On introduction - they were a 'picture' of an object - and uneditable.   The data was then used to push to Storm Sewer and SSA.  The following years - grips were provided [allowing the user to edit in our out the flat spots of a bad TIN] - the following year or two - the ability to split a large catchment into two smaller objects was added.  [To handle Transportation design workflow of the Sag Inlet - and working up to the on Grade inlets]   The theory (computational assumptions of Catchment Area simple object) remained intact [inifinite thin] since it was originally implemented well before 'object' came into existence.   

 

For IWK - the C3D catchment theory is too slow and too precise for the dull data and size of data that IWKs takes by default - based on the persona it was designed for - transportation planner in search of many culvert crossings along a road.  

 

For C3D as a 'black' box solutions to work - feed it a proper TIN surface, and know what will stop the catchment delineation algorithm.  

 

 

Matthew Anderson, PE CFM
Product Manager
Autodesk (Innovyze)

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