How to "fix" stream lines where Topaz doesn't create a stream

[climatechniques]

I work at the Watershed scale, and as such I delineate a large number of individual basins.

The Topaz created streamlines from a DEM for the most part are very good and known (digitized streamlines) agree well with it.

But, for those instance where Topaz does not create a stream line where there is a known (and verified) streamline on the landscape, is there a way to adjust or add in a streamline so that I can delineate a particular basin?

Typical of my work, I'm trying to delineate basins with outlets at road/stream intersections (culverts...).

I've tried adjusting the threshold, hoping for the stream that I need to show up, but to no avail.

What are my options in these situations?

[Clark Barlow]

You have a couple options. You could turn on your flow vectors and adjust them around your area of interest until you get the stream to show up. You do this by double clicking on a DEM cell and changing the flow direction arrow. Another option is editing the DEM elevations. For example, if you have survey data of the area, you could merge that with the DEM in hopes of TOPAZ defining the stream in that area correctly.

I hope that helps.

Clark

[climatechniques]

Thanks, I didn't realize that I could edit those.

I'll see if that helps.

Is there an option in WMS that will allow you to "burn in" streams from a vector file so as to initially set up the dem with those streamlines as "preferred" paths?

There was an option in some of the ArcGIS tools to burn in streams, but I haven't seen an option like that in WMS.

-Thomas

[Clark Barlow]

Thomas-

Yes, you could do this as well. The only drawback to this method is that it often creates a very abrupt transition between the overland area and the stream channel, creating artificially high slopes along the stream bank. This can throw off some of the parameters WMS computes for the watershed, such as mean basin slope. But if all else fails, you could try this, particularly if the model you're running doesn't depend on the slope-related parameters.

-Clark

[climatechniques]

So how is that done in WMS??

Or do I have to do it another app?

-Thomas

[Clark Barlow]

Thomas-

You can do this in WMS. It involves editing the DEM elevations using an arc. See our online help page for more info:

http://www.xmswiki.com/xms/WMS:Editing_DEM_Elevations

-Clark

[Watershed]

Hi,

I'm an engineer working in modeling watershed's and i use the WMS 8.1. I encoutred problems in manipulationg the modeling procedures like Thomas.

I have taken my bassin from a GMS map and open it with the wms, converted it to a DEM to take the elevations.

when i tried to compute the TOPAZ, it not create the stream lines.

there is a resolution to this problem??

can i send you the model to have more information about??

[Nathan Dye]

Hi,

I'm an engineer working in modeling watershed's and i use the WMS 8.1. I encoutred problems in manipulationg the modeling procedures like Thomas.

I have taken my bassin from a GMS map and open it with the wms, converted it to a DEM to take the elevations.

when i tried to compute the TOPAZ, it not create the stream lines.

there is a resolution to this problem??

can i send you the model to have more information about??

You can send your files to support@aquaveo.com and we will take a look at them.

[Watershed]

I've sent all the information

Selim,

[cameronj]

I've sent all the information

Selim,

The flow accumulation value is what decides when a stream is created in TOPAZ. You can change this in the display options. The value represents the amount of area contributing to the stream from upstream.

Cameron

[Watershed]

The flow accumulation value is what decides when a stream is created in TOPAZ. You can change this in the display options. The value represents the amount of area contributing to the stream from upstream.

Cameron

I changed the flow accumulation value and it's the sale no stream line created :s .

how can i create shapefiles for the land use and soil type coverages. arcview, GIS, GMS???

thank you Cameron

Best regards,

Selim

[cameronj]

I changed the flow accumulation value and it's the sale no stream line created :s .

how can i create shapefiles for the land use and soil type coverages. arcview, GIS, GMS???

thank you Cameron

Best regards,

Selim

Selim,

How big of an area is your DEM your running topaz on? If you know what the stream should look like, you can draw it in manually.

Landuse and Soil shape files can be created in ArcGIS/Arcview, but you can usually download shapefiles already created from government websites or try here

Cheers,

Cameron

[Watershed]

Selim,

How big of an area is your DEM your running topaz on? If you know what the stream should look like, you can draw it in manually.

Landuse and Soil shape files can be created in ArcGIS/Arcview, but you can usually download shapefiles already created from government websites or try here

Cheers,

Cameron

Cameron,

my watershed area i work on is about 0.4Km2, i know why the stream look like but what's the steps i should took to draw it manually???

can I send you the file i have so you can help me. it's the first time i work in modeling watershed's that's why i find difficulties.

Best regards,

selim,

[cameronj]

Cameron,

my watershed area i work on is about 0.4Km2, i know why the stream look like but what's the steps i should took to draw it manually???

can I send you the file i have so you can help me. it's the first time i work in modeling watershed's that's why i find difficulties.

Best regards,

selim,

Check the following site: http://xmswiki.com/xms/WMS:DEM_Guidelines

There are tutorials that come with the software and can be found here: http://xmswiki.com/xms/WMS:WMS_Tutorials

They will give you step by step directions on how to model a watershed.

Cheers,

Cameron

[Watershed]

Check the following site: http://xmswiki.com/xms/WMS:DEM_Guidelines

There are tutorials that come with the software and can be found here: http://xmswiki.com/xms/WMS:WMS_Tutorials

They will give you step by step directions on how to model a watershed.

Cheers,

Cameron

Hi Cameron,

thanks for your help ut i have another problem,

when i convert the *.dwg file to a TIN , i can't triangulate it, when i try to to change the scale the program crache

i contunue and when i try to compute the topaz, stream lines dosen't show and i have this error:

AN ERROR IN INPUT WAS DETECTED;

RECORD NUMBER: 67

[cameronj]

Hi Cameron,

thanks for your help ut i have another problem,

when i convert the *.dwg file to a TIN , i can't triangulate it, when i try to to change the scale the program crache

i contunue and when i try to compute the topaz, stream lines dosen't show and i have this error:

AN ERROR IN INPUT WAS DETECTED;

RECORD NUMBER: 67

This is something I would send to support@aquaveo.com to see why the program is crashing.

Cameron

[Watershed]

This is something I would send to support@aquaveo.com to see why the program is crashing.

Cameron

Dear Cameron,

thx for your help, can i ask u if there is an evaluation complete version of WMS that i can use to do the job because the version that i have buyed is broken and i should finish the job with that i have :s.thanks to u in advance .

Best regards,

Selim

[cameronj]

Dear Cameron,

thx for your help, can i ask u if there is an evaluation complete version of WMS that i can use to do the job because the version that i have buyed is broken and i should finish the job with that i have :s.thanks to u in advance .

Best regards,

Selim

Selim,

You should be able to download the latest version of WMS and test it out for 30 days. They do update the software every few months so this may have fixed any problems you may have.

Cheers,

Cameron