Modeling of damaging extreme events is of great interest for the risk managers who want to implement some protections. It is based on the so-called generalized extreme values model. In the environmental sciences, we need to model the extremes of two or more processes like the daily rainfall recorded in various points of a given region. Each individual process could be modeled using univariate technique, but this strategy could not take into account for dependence of extreme values. For instance, consider two sites A and B fairly close to one another. If we observe an extreme value of the daily rainfall at site A, this information impacts the probability to observe an extreme value at site B even if we never recorded such value at B. The basic modeling tool is formed by so-called max-stable processes which take into account the possible spatial dependence through so-called extremal coefficient. We illustrate with annual maximum daily rainfall values recorded in 41 stations in Burkina Faso