Dear Dr. Utset,

Thank you for the answer and the link!

I have downloaded and installed LARS. I also successfully created my own site-files
and computed a *.tst file.
Yet, still I am lost were I could "perturbate" the model so that it would create daily rainfall data for the years where I only have the monthly sums.

This is the part of the *.tst file where some statistics are displayed:

[NAME]
TelHadya
[LAT, LON and ALT]
   36.01   36.93  285.00
[SERIES: WET/Dry - degree of freedom, chsq-values and probabilities]
   DJF     9     1.00    0.999
           9     6.85    0.653
   MAM     6     0.89    0.990
           7     0.32    1.000
   JJA     2     0.49    0.782
           2     0.13    0.936
   SON     6     0.49    0.998
           8     6.62    0.579
[RAIN distribution: degree of freedom, chsq-values and probabilities]
     J     8     2.58    0.958
     F    11     9.12    0.611
     M     6     2.33    0.887
     A     7     1.20    0.991
     M     7     3.21    0.864
     J     2     0.21    0.898
     J     0     0.00    1.000
     A     1     0.00    1.000
     S     2     0.08    0.963
     O     8     5.06    0.751
     N    10     4.76    0.907
     D     8     6.69    0.570
[RAIN MONTHLY: obs/wg mean and sd, t- and f- values and probabilities]
    J      F      M      A      M      J      J      A      S      O      N      D
 69.2   55.8   50.8   30.5   15.0    1.7    0.0    0.6    3.5   22.4   44.9   56.7
 30.75  30.73  35.89  25.81  19.76   3.66   0.00   2.73   6.87  20.52  24.31  29.82
 73.4   56.3   56.7   31.1   16.3    1.4    0.3    1.1    2.5   23.4   41.9   67.4
 31.18  29.86  32.96  29.13  17.10   2.88   1.82   3.23   5.13  24.64  27.55  38.46
 -0.57  -0.07  -0.75  -0.09  -0.31   0.42  -0.77  -0.67   0.78  -0.18   0.47  -1.22
 0.567  0.944  0.456  0.929  0.754  0.675  0.442  0.501  0.439  0.860  0.638  0.223
 1.03   1.06   1.19   1.27   1.34   1.62 1000.00   1.40   1.79   1.44   1.28   1.66
 0.994  0.808  0.561  0.538  0.344  0.121  0.000  0.382  0.059  0.340  0.523  0.182
...[rest not shown]

Would you now suggest modifying the table at the very end, entering my observed monthly data, plus increasing the probabilities to 1, so that these data would be generated?
Is it that what you mean?
BUT, remember I have 45 years with monthly sums! Going year by year in this way might be a bit awkward. Still I could do this, if you confirm that this is what you'd suggested.

Best regards,
Rolf


> -----Original Message-----
> From: DSSAT - Crop Models and Applications
> [mailto:[log in to unmask]] On Behalf Of Ángel Utset Suastegui
> Sent: Thursday, July 17, 2008 11:00
> To: [log in to unmask]
> Subject: Re: disaggregate monthly rainfall data
>
> There are several weather generators available.
> They can be classified in parametric and non-parametric. Theoretically,
> the non parametric should give better results.
> You could try both methods.
> I would recommend LARS-WG that ca be freely downloaded from the
> Rothamstead Exp. Station web page, as well as with a manual.
> LARS-WG is one of the most used weather generators and the only non-
> parametric I know!
> You will need a daily series (you already have it). You can obtain
> realizations for the unknown period by "perturbating" LARS-WG with the
> changes in the monthly means. It is not hard to do.
>
>
> Good luck!
>
> Dr. A. Utset
> ITACYL
> Ctra. Burgos km 119, 47071 Valladolid
> ESPAÑA - SPAIN
>