# Editing default vegetation type chosen for non-urban land in SLUCM

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#### timchambers96

##### New member
Hi, I'm tring to trying to run the single layer ucm to get a more accurate picture of my study cities. I've integrated the extra urban land use classes (31,32,33) and have been playing around with the FRC_URB for the different classes. I am getting warmer daytime temperatures with lower FRC_URBAN values and realise this is probably to to the non-urban land being assigned as grass (or similar) rather than trees (which is what it actually is in my cases). I've been trying to work out how to change this default vegetation (to forest) but can't seem to find a simple way.

If anyone has some ideas of a simple fix (or potentially more complex editing of the modules+some guidance) I'd really appreciate it!

Also, if someone knows whether this non-urban land is calculated by the ucm or by the lsm?

Thanks!

Tim

Tim,
If you look at the code module_sf_noahdrv.F, you can find the following piece of code:
Code:
``````           IF(SF_URBAN_PHYSICS == 1.OR. SF_URBAN_PHYSICS==2.OR.SF_URBAN_PHYSICS==3 ) THEN
IF( IVGTYP(I,J) == ISURBAN .or. IVGTYP(I,J) == LOW_DENSITY_RESIDENTIAL .or. &
IVGTYP(I,J) == HIGH_DENSITY_RESIDENTIAL .or. IVGTYP(I,J) == HIGH_INTENSITY_INDUSTRIAL) THEN
VEGTYP = NATURAL
SHDFAC = SHDTBL(NATURAL)
ALBEDOK =0.2         !  0.2
ALBBRD  =0.2         !0.2
EMISSI = 0.98                                 !for VEGTYP=5
IF ( FRC_URB2D(I,J) < 0.99 ) THEN
if(sf_urban_physics.eq.1)then
T1= ( TSK(I,J) -FRC_URB2D(I,J) * TS_URB2D (I,J) )/ (1-FRC_URB2D(I,J))
elseif((sf_urban_physics.eq.2).OR.(sf_urban_physics.eq.3))then
T1=tsk_rural_bep(i,j)
endif
ELSE
T1 = TSK(I,J)
ENDIF
ENDIF``````

I believe you can change the line "VEGTYP = NATURAL" for your case.