because agriculture is the main activity in the plain. The rates of the net recharge, aquifer media, hydraulic conductivity, impact of vadose zone, soil media, and topography were modified based on the mean nitrate concentration. The highest and lowest rates were assigned to the highest and lowest mean nitrate concentrations, respectively, and the remaining rates were linearly modified. That means that the average of nitrate in every class was applied to compute the modified rate from each DRASTIC parameter according to the Wilcoxon rank-sum nonparametric statistical test. The classes of each parameter of DRASTIC, as well as the relevant rating of each class, the nitrates concentration average and the respective modified rating of every class are illustrated. Moreover, if there is no mean nitrate concentration in each class, the original rate of DRASTIC for each class would be assigned. Table 5 shows the modified DRASTIC–AHP, in which the rates and weights of the DRASTIC method were derived using the nonparametric Wilcoxon rank-sum statistical test and AHP, respectively.