Assessing diffuse and concentrated recharge in average and dry rainfall year in a semiarid carbonate sloping aquifer a preliminary report

The chloride mass balance (CMB) method was applied in the unsaturated zone to estimate potential recharge (Rt) rainfall in two small catchment of southern mid-to-high slope of Sierra de Gador carbonate aquifer (SE Spain) , in the average hydrological year 2003-04 and the unusually dry 2004-05. Unknown fractions of diffuse (RD) and concentrated recharge (Rc) into Rt were firstly evaluated to fit average and lower RT thresholds for modeling further long-term recharge. Daily rainfall and actual evapotranspiration (AET) from the Eddy Covariance (EC) technique provided yearly RT of 189 mm year-1 in 2003-04 and 8 mm year-1 in 2004-05.