## 4 Results
### Groundwater Resource Evaluation
\begin{table}
\begin{tabular}{c c c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Age**} & \multicolumn{2}{c}{**Hydrogeological**} & \multirow{2}{*}{**Main Lithology**} & \multicolumn{2}{c}{**Urbana Surface**, **NRUS Surface**, **NRUS Surface**, **NRUS** **m3**} & \multicolumn{2}{c}{**Tickness, m 3**} & \multicolumn{2}{c}{**Femmability**, **Effective**, **Pensity**, **V**} & \multicolumn{2}{c}{**PCS in the**} & \multicolumn{2}{c}{**PCS in the**} & \multicolumn{2}{c}{**Hydraulic**} \\  & **Formation** & & & & & & & & & & \\ \hline \multirow{3}{*}{Palacouic} & Belrock & Mica-schbits, quartz-schbits & 1.82 & 0.77 & – & – & – & – & – & – & Aquilade \\ \cline{2-11}  & Weinbrecher & Mica-schbits, quartz-schbits & 0.86 & 0.68 & 1-18 (8) & 0.93-15(1.1) & 0.20-07(0.05) & 0.02-108 (0.34) & 0.01-08 (0.27) & Aquilade \\ \cline{2-11}  & featured bedrock & Mica-schbits, quartz-schbits & 0.86 & 0.68 & 1-18 (8) & 0.93 -15(1.1) & 0.20-07(0.05) & 0.02-108 (0.34) & 0.01-08 (0.27) & Aquilade \\ \cline{2-11}  & Distance & Delitalic indices & Sand, gravel, silt & 0.09 & – & 4-31 (7) & 1.1-52(2.5) & 0.01-05(0.02) & 0.01-014 (0.03) & – & Aquilade \\ \hline \multirow{3}{*}{Peliacouic} & Littonal facies (1), & Gravel, sand & 0.41 & 0.41 & 1-8 (8) & 2.3-9(3.42) & 0.05-017 (3.13) & 0.03-05(0.21) & 0.03-053 (0.21) & Aquilade \\ \cline{2-11}  & Detail cultural (g1, g2) & Gravel, sand, clay & 0.58 & 0.58 & 1-32 (9) & 0.05-00(0.01) & -0.01-02 (0.00) & -0.01-02 (0.00) & Aquilade \\ \cline{2-11}  & Cemmel & Gravel, sand & 0.10 & – & 1-29 (4) & 0.12-04 & 0.01-03(0.02) & 0.01-009 (0.03) & – & Aquilade \\ \hline \multirow{3}{*}{Holocene} & Adra River Delta & Sand, silt & 0.35 & 0.11 & 1-21 (9) & 0.82-29 (1.4) & 0.15-010(0.01) & 0.02-07(0.22) & 0.01-013 (0.07) & Aquilade \\ \cline{2-11}  & \multicolumn{2}{c}{Proset internal} & Sand & 0.59 & – & 1-35 (9) & 0.05-00(0.01) & 0.02-248 (0.79) & – & Aquilade \\ \cline{2-11}  & \multicolumn{2}{c}{Colural} & Gravel, sand, clay & 0.17 & – & 1-9 (4) & 5.1-303 (0.80) & 0.01-07(3.13) & 0.01-026 (0.09) & – & Aquilade \\ \cline{2-11}  & Anthropogenic & \multicolumn{2}{c}{Blocks, sand, silt } & \multicolumn{1}{c}{0.17} & 0.05 & 1-6 (3) & 5.2-82(6.7) & 0.14-023(0.17) & 0.02-024 (0.09) & \multicolumn{1}{c}{\(<\)01-07 (0.03)} & Aquilade \\ \cline{2-11}  & \multicolumn{2}{c}{} & \multicolumn{2}{c}{} & \multicolumn{2}{c}{} & \multicolumn{2}{c}{} & \multicolumn{2}{c}{} & \multicolumn{2}{c}{} & \multicolumn{2}{c}{} & \multicolumn{2}{c}{} \\ \hline \multicolumn{11}{c}{\({}^{1}\) Surface of Adra River Delta} & 1.82 km3  & and surface of the NRUS is 0.77 km3  & \multicolumn{2}{c}{**} & \multicolumn{2}{c}{} & \multicolumn{2}{c}{} & \multicolumn{2}{c}{} & \multicolumn{2}{c}{} \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Geometry, hydraulic data, and potential groundwater storage (PCS) of the hydrological formations in the total urban area and the NSUS. Excluding g1 and g2 behaving as aquitards, the average NSUS groundwater discharge is around 0.28 Mm\({}^{3}\) year\({}^{-1}\). This figure varies in the 0.03-1.02 Mm\({}^{3}\) year\({}^{-1}\) range when the minimum and maximum values of saturated thickness and permeability are considered (Table 3). Average actual groundwater storage (AGS), which is expressed as the product of surface (direct and underlying outcrops as in Table 2), saturated thickness, and effective porosity (Table 2), is around 0.47 Mm\({}^{3}\) (Table 3). NSUS groundwater discharge was compared to groundwater recharge produced from precipitation in the peri-urban area (2.64 km\({}^{2}\)) and NSUS (0.77 km\({}^{2}\)), irrigation return in the southern peri-urban sector devoted to irrigation agriculture in greenhouses (1.41 km\({}^{2}\)), and urban return in the NSUS (Table 4). Using tracer and physical techniques, [PERSON] et al. (2008) [15] tentatively evaluated the average recharge rate from precipitation in the peri-urban and urban areas as 10 mm year\({}^{-1}\). This figure is similar to that reported by [PERSON] et al. (2011) [68] in coastal areas in southern Almeria province.