lup.dat -- Land Use Update quirks

[Jim Almendinger]

Just reporting a few quirks in using the land-use update module in swat2012 (rev 635):

See chapter 37 in the swat input/output manual for more details.

To run the module, create a lup.dat file, which will contain the filenames of the data files where the new hru_fr values are given.

For example, my lup.dat file for two land-use updates is the following (spaces are important -- see Ch 37 for exact format):

    1    1    1 1990 Lup1990s.dat
    1    1    1 2000 Lup2000s.dat

The first number is a sequential number, then month, day, year (sorry, rest-of-the-world -- our odd American date convention), and finally data filename.  My hru_fr values are given in the two data files, Lup1990s.dat and Lup2000s.dat.  All 3 files (lup.dat and the two data files) go into the txtinout folder.

Things to be careful about:

(1) The first number on each line apparently needs to be 1 (one).  When I put a 2 on the second line, SWAT crashed with a floating point error.  (I didn't test other numbers.)

(2) Your model run must start BEFORE (or on) the date on the first line.  If I started my model run after 1/1/1990 (in my case), the model completed successfully but ignored my requested change on 1/1/2000.  Apparently (and logically), SWAT is watching for the date of the first change to occur -- and if the model starts after this date, SWAT never sees this date for the first change, and never implements that or subsequent changes.  So the model runs successfully with the original hru_fr values it had, but just didn't do exactly what you wanted. 

Cheers,

-- Jim

--

Dr. James E. Almendinger
St. Croix Watershed Research Station
Science Museum of Minnesota
16910 152nd St N
Marine on St. Croix, MN  55047
tel: 651-433-5953 ext 19

[Idhayachandhiran Ilampooranan]

Dear Dr. James

I'm using SWAT2012 rev.635 and my model has land use files for the following years. Even after providing all necessary details, the land use module fails to update the area fraction.

I had run the simulation from 2000 to 2007 and checked the area of HRUs in the output.hru or output.mgt files, also checked flow in output.rch file. The model reads only the first line in my lup.dat and doesn't consider next 4 lines. It is not even throwing an error.

    1    1    1 2003 Lup2003.dat

    1    1    1 2004 Lup2004.dat

    1    1    1 2005 Lup2005.dat

    1    1    1 2006 Lup2006.dat

    1    1    1 2007 Lup2007.dat

I have tried even with sequential numbers (1,2,3,4 and 5) instead of 1 (one) in the first column. Nothing works. I'm sure it is a format issue, but couldn't fix it.

It would be great if you could clarify.

Thanks

Idhaya

[Jim Almendinger]

Dear Idhaya --

Sorry -- I don't know what could be wrong.  It looks like you've tried some of the obvious options.  All I can suggest is to simplify your land use changes, starting with just one, and see if you can get that one to work.  If so, then add a second, and so forth.  I presume you're starting with 2000 land use, and then see if you an get it to change to the 2003 land use, to start with.  I wouldn't worry about future years until you can get this first one to work.  I realize this is slow and frustrating, but it is the way I've figured out many of ArcSWAT and SWAT's quirks.  And if there are bugs in the system, there is no guarantee that any method, however careful, will work... 

Good luck,

-- Jim

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From: "Idhayachandhiran Ilampooranan" <idhayach...@gmail.com>
To: "SWAT-user" <swat...@googlegroups.com>
Sent: Saturday, January 9, 2016 5:44:51 PM
Subject: [SWAT-user:5956] Re: lup.dat -- Land Use Update quirks

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[Idhayachandhiran Ilampooranan]

Dear Dr.James

Thank you for the reply. Actually, my land use update starts from 2003. The model updates the land use values only for the year 2003 but not for the subsequent years. I have done all possible combinations, but nothing helps. I had written to Naresh Pai also, who had developed this module. Will wait and see whether he could solve this issue.

Thank you for your time.

Thanks

Idhaya

[Jim Almendinger]

Just to clarify -- you can get one update to work fine, but not the second (or third, etc.)?  You start with some pre-2003 land-use values (hru_fr values), they update fine to 2003 values, but then don't change after that? 

If you get it to work for one update, then that implies to me that your files are probably formatted correctly -- and there is some other quirk or bug that might be causing a problem. 

I only used one update in my model so I didn't fully check subsequent years. 

-- Jim

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From: "Idhayachandhiran Ilampooranan" <idhayach...@gmail.com>
To: "SWAT-user" <swat...@googlegroups.com>

Cc: "Idhayachandhiran Ilampooranan" <idhayach...@gmail.com>
Sent: Sunday, January 10, 2016 9:50:09 PM
Subject: Re: [SWAT-user:5959] Re: lup.dat -- Land Use Update quirks

[Idhayachandhiran Ilampooranan]

Dear Dr. James

Yes. The model updates fine to the year 2003 and don't change for subsequent years.

Like you said, it may be other quirk or bug.

Thanks

Idhaya

[marios kamp]

Dear dr.Jeams,

can you attach the files, to use their format?