The file is located in the modeldir folder. The file is used for the calculation of regional estimated parameters by regression. This is used when model option regestimate is set in info.txt. The file contains coefficients for regression equations for each group. Which catchments belong to which group is given in CatchGroup.txt. The catchment descriptors which are being regressed is given in CatchDes.txt.

The first row of the reg_par.txt file gives the number of regional parameters. Then follow two rows for each parameter for a given group of catchments. The first row of each parameter contains the coefficients and the second row the corresponding catchment descriptor to apply the coefficient to. Information for all parameters is given first for group one, then group two etc.

The following parameters are possible to estimate with regression: lp, cevpam, cevpph, rivvel, damp, tcalt, tcelevadd, tempcorr, pcelevmax, pcelevadd, pcelevth, cevpcorr, rrcscorr, rrcs3, pcurain, and pcusnow. For description of the parameters see par.txt.

The example below shows entries for regionalizing three parameters (tcalt,cevpcorr,and tcalt) in a model setup where there are two groups of catchments.

Example of a reg_par.txt file structure:

3
tcalt	0.6
tcalt	1
cevpcorr	0.1	-0.1	-0.2	0.3
cevpcorr	1	8	9	10
tcalt	0.6
tcalt	1
cevpcorr	0.1	0.0	-0.1	0.4
cevpcorr	1	8	9	10
tcalt	0.5
tcalt	1
cevpcorr	-0.1	0.3
cevpcorr	8	10