Figure 5 shows the autocorrelation of the greenness index represented by I's Moran. As the value of I is positive and its magnitude quite high (I = 0.67), it means that as we observe a cell of the grid having a high value of greenness index, there is quite good chance we observe the cell neighbooring the lastest having a high value of greenness index. We generated a procedure of 999 random permutation in order to study the degree of spatial structuration of this geographically distributed phenomena. We obtain a p-value equals to 0.001 for 999 random permutations.