DRASTIC parameter: R (Net recharge). Upper Guadiana Basin (UGB).

R parameter represents the net recharge per unit area. The values of the recharge (mm) are classified into six classes and a rate is assigned to each class (<50 mm = [1]; 50 - 100 = [3]; 100 - 175 = [6]; 175 - 250 = [8]; 250 - 500 = [9]; >500 = [10]). In the Upper Guadiana Basin pilot, rainfall is the main source of aquifers recharge. The mean annual recharge varies between 45 and 70 mm/year.