## 3 Data Compilation  
A data search was conducted to examine the feasibility of existing geophysical prospecting surveys in groundwater research in the MDQ. The rationale was to create a database to cover as many geological formations (preferably those catalogued as aquifers), research interests, and prospecting techniques as possible. The selection prioritized geophysical surveys that explored depths of at least 10 m and used external validation data, such as geotechnical soundings logs and/or additional prospecting techniques. The selection also considered those surveys developed or promoted by the EPMAPS in sites where it has (or intends to have) operative water catchments. Therefore, EPMAPS' public repository (information available on request), official geotechnical research reports, and the scientific literature were consulted. Finally, 23 representative surveys covering the abovementioned scopes and priorities were selected to build the database in Table 2. Most of the compiled surveys were performed in the IAV sector (Figure 1b). \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Lithology**} & \multirow{2}{*}{**Age**} & \multirow{2}{*}{**MDQ Sector 1**} & \multicolumn{2}{c}{**Permeability 2**} & \multirow{2}{*}{**Effective**} & \multirow{2}{*}{**Reference**} \\ \cline{5-6}  & & & & **Magnitude** & & **Type** & **Porosity 3** \\ \hline Metapelites & Paleozoic & EAC & 10\({}^{-4}\)–10\({}^{-2}\) (nd) & fr,fi & nd & [25,26] \\ Andesites and basalts & Cretaceous & WAC & 10\({}^{-4}\)–10\({}^{-2}\) (nd) & fr,fi & nd & [25] \\ Sandstones and siltstones & Cretaceous & WAC & 10\({}^{-2}\)–10\({}^{-1}\) (nd) & fr,fi & nd & [25] \\ Andesite lavas & early Pleistocene & IAV & 10\({}^{-2}\)–10\({}^{-1}\) (0.04) & fr,fi & nd & [26] \\ Andesite lavas & middle Pleistocene & IAV & 10\({}^{-2}\)–10\({}^{-1}\) (0.04) & fr,fi & 0.02–0.08 & [26,33,34] \\ Pyroclastic flows & middle Pleistocene & IAV & 0.13–0.86 (nd) & fr,fi & nd & [25,26] \\ Ash & middle Pleistocene & IAV & 10\({}^{-3}\)–10\({}^{-1}\) (0.01) & fr,fi & nd & [25,26] \\ Ash & late Pleistocene & IAV & 10\({}^{-3}\)–10\({}^{-1}\) (0.01) & fr,fi & -0.01 & [26,33,34] \\ Fluvio-glacial deposits & late Pleistocene & IAV & 0.05–10 (1.02) & fi,ip & 0.01–0.03 & [25,26] \\ Ash & Holocene & IAV & 10\({}^{-3}\)–10\({}^{-1}\) (nd) & fr,fi & nd & [25,26] \\ Avalanche flows & Holocene & IAV & 10\({}^{-2}\)–10\({}^{-1}\) (nd) & fr,fi & nd & [25,26] \\ Lahar & Holocene & IAV & 10\({}^{-3}\)–10\({}^{-2}\) (0.01) & fr,fi & 0.01–0.06 & [26,33,34] \\ Aluvial & Holocene & IAV & 0.05–0.18 (0.12) & ip & 0.05–0.12 & [25,26] \\ Glacier and moraines & Holocene & IAV & 0.05–0.15 (0.09) & ip & 0.05–0.15 & [25,26] \\ \hline \hline \end{tabular}  
* EAC—Eastern Andean Cordillera, WAC—Western Andean Cordillera, and IAV—Inter-Andean Valley. 2 Permeability in m d\({}^{-1}\); magnitude refers to theoretical ranges and experimental values after borehole surveying (in parenthesis); fr—fracratation, fi—fissuration, and ip—intergranular porosity. 3 Effective porosity as a fraction; magnitude refers to experimental values after borehole surveying. nd—no data.  
\end{table} 
Table 1: Compiled information regarding the permeability and effective porosity of representative geological formations in the MDQ. \begin{table}
\begin{tabular}{c c c c c c c c c c c c c c c c c c c c c c c c} \hline \hline ID & **Conclintense** & \multicolumn{3}{c}{**Erosion**} & \multicolumn{3}{c}{**C Geophysical**} & \multicolumn{3}{c}{**Geological Environment\({}^{\dagger}\)**} & \multicolumn{3}{c}{**Research**} & \multicolumn{3}{c}{**Additional Technical Information\({}^{\dagger}\)**} & \multicolumn{3}{c}{**Reference**} \\  & & **m.a.h. ** & & **  
Survey information was catalogued according to: (1) the applied prospecting technique; (2) the explored aquifer typology; (3) deduced transient groundwater features; and (4) additional technical information, such as the magnitude of the geophysical variables in geological formations catalogued as aquifers and aquitards, and prospecting length and depth (Table 2).