The given GR4J **X4u** variable does not correspond to the actual GR4J **X4** parameter. As explained in @andreassian_seeking_2014 [section 2.1], the given GR4J **X4u** value has to be adjusted (rescaled) using catchment area (S) [km2] as follows: $X4 = X4u / 5.995 \times S^{0.3}$ (please note that **the formula is erroneous in the publication**).

The given GR4J **X4u** variable does not correspond to the actual GR4J **X4** parameter. As explained in @andreassian_seeking_2014 [section 2.1], the given GR4J **X4u** value has to be adjusted (rescaled) using catchment area (S) [km2] as follows: `X4 = X4u / 5.995 * S^0.3` (please= note that **the formula is erroneous in the publication**).

It means we need first to transform the **X4** parameter.