Spatial Analyst - how to model rivers

[ChristopherJursa]

Hi,

A client of mine needs a layer of new streams in an area of interest.

My source data is 1 meter LIDAR data in a GRID format.

What is the most effective way to model streams?  I am only looking for how to get started.

I obtained the flow accumulation but the results seem a little scattered.  Should I reduce the resolution with an aggregate?

Also, my client informed me to look at ArcHydro.  How does this compare to the tools found in Spatial Analyst?

Thanks in advance!

[JeffreyEvans]

Arc has often produced rather dubious results in stream delineations. This is primarily due to the use of the D8 algorithm. With very high resolution data the problem of inadequate flow routing is quite notable. David Tarboton developed an alternative algorithm for calculating flow direction (D-infinity) that yields much better results, particularly on lidar derived DEM's. Conveniently he has written an ArcToolbox with a suite of tools for performing exactly the analysis you are after. http://hydrology.neng.usu.edu/taudem/taudem4.0/index.html

[dustinatwater1]

The weblink has changed. This is the new link:

http://hydrology.usu.edu/taudem/taudem4.0/taudem40.html

[NawajishNoman]

Hi VanJay011379,

Did you fill (by running the Fill) your 1 meter LIDAR elevation data before creating flow direction?

Please refer to Creating a depressionless DEM and Identifying stream networks if you need additional information.

The ArcHydro tools internally use Spatial Analyst tools to perform analysis.

Thanks,

Nawajish Noman
Esri