suggestion about how update land use percentage in edit arc-SWAT input data

[abdul basit]

Hello sir,

I have a calibrated arc swat model till 2010, now I want to run model for 2017 by changing landuse and land cover percentage and climate data, In my study area forest increased about 5%, how can I add this, through edit SWAT input data please guide me about procedure to add forest increases 5%.

[Jim Almendinger]

I believe the land-use update tool in SWAT simply replaces one set of hru_fr values with another -- but you still have to prepare the new hru_fr values ahead of time (apologies if this has changed). 

You can manually change the hru_fr values, probably most easily in Excel, although it may be tedious.  If you increase forest in each subbasin by 5%, you will need to decrease the hru_fr values for all the other land-uses in the subbasin by a fractional amount so that the sum of hru_fr values in each subbasin still adds up to 1. 

This is not a perfect method because it assumes other attributes of the hru (soil and slope) expand or contract as you expand or contract the whole hru in order to change land use.  But usually (we hope) land use is the biggest factor in that change. 

-- Jim

On Mon, Jul 5, 2021 at 7:37 AM abdul basit <agrar...@gmail.com> wrote:

Hello sir,

I have a calibrated arc swat model till 2010, now I want to run model for 2017 by changing landuse and land cover percentage and climate data, In my study area forest increased about 5%, how can I add this, through edit SWAT input data please guide me about procedure to add forest increases 5%.

--
You received this message because you are subscribed to the Google Groups "SWAT-user" group.
To unsubscribe from this group and stop receiving emails from it, send an email to swatuser+u...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/swatuser/71cd89a5-b262-4287-8bb8-ca79317edfe4n%40googlegroups.com.