diff --git a/DESCRIPTION b/DESCRIPTION
index b2f5df39a96da0ab467ea019dc4e86467ab327c6..710083766a7f7fb8f8304ac7b99b3dd96f6c5ce5 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -1,7 +1,7 @@
 Package: airGR
 Type: Package
 Title: Suite of GR Hydrological Models for Precipitation-Runoff Modelling
-Version: 1.4.2.7
+Version: 1.4.2.8
 Date: 2019-12-10
 Authors@R: c(
   person("Laurent", "Coron", role = c("aut", "trl"), comment = c(ORCID = "0000-0002-1503-6204")),
diff --git a/NEWS.md b/NEWS.md
index 9119f0952d00591c2e8414b3769af5aff4fe3c3f..bf5d743491257ee1752d6431cf73663816815aaf 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -2,7 +2,7 @@
 
 
 
-### 1.4.2.7 Release Notes (2019-12-10)
+### 1.4.2.8 Release Notes (2019-12-10)
 
 
 #### New features
diff --git a/man/Imax.Rd b/man/Imax.Rd
new file mode 100644
index 0000000000000000000000000000000000000000..41d2a692734e8c9843566bcbacb3f918c6ab4c25
--- /dev/null
+++ b/man/Imax.Rd
@@ -0,0 +1,103 @@
+\encoding{UTF-8}
+
+
+\name{Imax}
+\alias{Imax}
+
+
+\title{Compute the maximum capacity of the GR5H interception store}
+
+
+\usage{
+Imax(InputsModel, RunOptions, Param)
+}
+
+
+\arguments{
+\item{InputsModel}{[object of class \emph{InputsModel}] see \code{\link{CreateInputsModel}} for details}
+
+\item{IndPeriod_Run}{numeric] index of period to be used for the model run [-]}
+
+\item{TestedValues}{[numeric] vector of tested Imax values}
+}
+
+
+\value{
+Choosen Imax value [mm].
+}
+
+
+\description{
+Function which performs a single run for the GR4J daily lumped model over the test period.
+}
+
+
+\details{
+For further details on the model, see the references section.
+For further details on the argument structures and initialisation options, see \code{\link{CreateRunOptions}}.
+\cr
+\cr
+\if{html}{\figure{diagramGR4J-EN.png}{options: width="60\%" alt="Figure: diagramGR4J-EN.png"}}
+\if{latex}{\figure{diagramGR4J-EN.pdf}{options: width=6cm}}
+}
+
+
+\examples{
+library(airGR)
+
+## loading catchment data
+data(L0123001)
+
+## preparation of the InputsModel object
+InputsModel <- CreateInputsModel(FUN_MOD = RunModel_GR5H, DatesR = BasinObs$DatesR, 
+                                 Precip = BasinObs$P, PotEvap = BasinObs$E)
+
+## run period selection
+Ind_Run <- seq(which(format(BasinObs$DatesR, format = "\%Y-\%m-\%d")=="1990-01-01"), 
+               which(format(BasinObs$DatesR, format = "\%Y-\%m-\%d")=="1999-12-31"))
+               
+## Imax compuattion
+Imax <- Imax(InputsModel = InputsModel, IndPeriod_Run = Ind_Run,
+             TestedValues = seq(from, 0.1, to 3, by = 1))
+
+## preparation of the RunOptions object
+RunOptions <- CreateRunOptions(FUN_MOD = RunModel_GR5H, Imax = Imax,
+                               InputsModel = InputsModel, IndPeriod_Run = Ind_Run)
+
+## simulation
+Param <- c(X1 = 680.673, X2 = -0.255, X3 = 197.651, X4 = 2.384, X5 = 0.174)
+OutputsModel <- RunModel_GR5H(InputsModel = InputsModel,
+                              RunOptions = RunOptions, Param = Param)
+
+## results preview
+plot(OutputsModel, Qobs = BasinObs$Qmm[Ind_Run])
+
+## efficiency criterion: Nash-Sutcliffe Efficiency
+InputsCrit  <- CreateInputsCrit(FUN_CRIT = ErrorCrit_NSE, InputsModel = InputsModel, 
+                                RunOptions = RunOptions, Obs = BasinObs$Qmm[Ind_Run])
+OutputsCrit <- ErrorCrit_NSE(InputsCrit = InputsCrit, OutputsModel = OutputsModel)
+}
+
+
+\author{
+Andrea Ficchi, Guillaume Thirel, Olivier Delaigue
+}
+
+
+\references{
+Ficchi, A. (2017).
+  An adaptive hydrological model for multiple time-steps:
+  Diagnostics and improvements based on fluxes consistency.
+  PhD thesis, Irstea (Antony), GRNE (Paris), France.
+\cr\cr
+Ficchi, A., C. Perrin and V. Andréassian (2019).
+  Hydrological modelling at multiple sub-daily time steps: model improvement via flux-matching.
+  Journal of Hydrology, 575, 1308-1327. doi: https://doi.org/10.1016/j.jhydrol.2019.05.084.
+}
+
+
+\seealso{
+\code{\link{RunModel_GR5H}},
+\code{\link{CreateInputsModel}}, \code{\link{CreateRunOptions}}.
+}
+