Comments on: Upslope area – D-infinity flow

By: Liu Jintao

Liu Jintao — Wed, 11 Feb 2009 01:48:19 +0000

thank you!! I have managed to solve it.

By: Steve

Steve — Tue, 10 Feb 2009 20:06:56 +0000

Liu—The else-branch is followed when s equals 0. I posted my complete upslope area implementation to the MATLAB Central File Exchange: http://www.mathworks.com/matlabcentral/fileexchange/15818

By: Liu Jintao

Liu Jintao — Tue, 10 Feb 2009 06:28:30 +0000

Hi, Steve I am trying to implement your program for Tarboton's algorithm. But I have some questions about his equation (3) as s = hypot(s1, s2). Since it gives a positive or zero value. What is the meaning for the following in your program.

if s > 0
    % Maximum down-slope is positive.
    r = (af(k_max) * rp(k_max)) + (ac(k_max) * pi / 2);
else
    % The pixel is in a flat area or is a pit.  Flow direction angle is
    % unresolved.
    r = NaN;
end

By: Steve

Steve — Tue, 18 Nov 2008 14:22:14 +0000

Ali—This whole series of posts is about D-infinity flow accumulation computation. I have MATLAB code posted on the File Exchange which you can use. If you are asking about how to do it in Arc GIS, then well, you're asking the wrong company. :-)

By: Ali

Ali — Fri, 14 Nov 2008 21:56:31 +0000

hi
thank you for guidance.
i need help too compute and draw flow accumulation for d-infinity.
arc gis extract drinage line for d8 algorithm(toolbox archydro)but don’t extrac drinage line for d infinity(taudem).
what do you think about drinageline for d-infinity?
sincerely

By: Steve

Steve — Thu, 30 Oct 2008 12:26:50 +0000

Ali—My upslope area code can be downloaded from the MATLAB Central File Exchange.

By: ali

ali — Thu, 30 Oct 2008 10:42:11 +0000

hi
i am writing my tese and subject is flow direction
i need determine flow accumulation by dinf algorithm,
but tau dem don’t don’t drawing drinage line by dinf.
how do i get your program?
sincerely