# Geohydroology of a Reference Mediterranean Catchment (Cilento UNESCO Geopark, Southern Italy)
## 2 Materials and Methods
### Hydro-Chemical Dataset  
Since 2013, the EC has been monitored at the main station (outlet) and at various stations located just upstream of the main tributary junctions and downstream from the perennial bedrock springs and seasonal outlets from the zero-order basins, with the aim of identifying the runoff and spring flow components and their chemical characteristics (Figure 2). The location of the monitoring activity was based on direct, detailed, multi-temporal hydro-geomorphological surveys and field measurements (hydro-geomorphologic monitoring system), which were oriented by the \"variable source areas\" concept [39] and the \"hydro-geomorphic paradigm\" [40]. In particular, the Q and EC data were  
\begin{table}
\begin{tabular}{p{12.3 pt} p{12.3 pt} p{12.3 pt} p{12.3 pt} p{12.3 pt} p{12.3 pt}} \hline \hline
**Landform, Component or Element** & **Hydro-Geomorphotype (HGT in [Bb])** & **Hydro-Geomorphological Behavior** & **Station Type for Sampled Water Sources** & **Temporal Resolution** & **EC Range (\(\mu\)s/cm)** \\ \hline \hline Upland, summit, peak, crest & Ridge & Groundwater recharge on bare bedrock and dominant excess information control after storm & -Springs -Control points & -Monthly -After heaviest storms & 250–300 \\ \hline Shoulder, side slope & Nose & Shallow soil, groundwater recharge area, prevailently excess infiltration runoff & -Spring -Control points & -Monthly -After heaviest storms & 250–300 \\ \hline Scapys, back-slope, foot-slope, walls-clues & Hillslope & Debris, deep soil, shallow aquifers, excess and sub-surficial & -Fioremeters -Control points & -Weekly -After heaviest storms & 120–180 \\ \hline Glen, swallet, scar & Hollow & Deep soil, shallow aquifer, veraulently excess saturation, delayed runoff production & Hollow & Monthly & 120–180 \\ \hline V-shaped stream, gully, bank, stream bed & Riparian corridor & Shallow soil, groundwater discharge, prevailently sub-surface, delayed return flow and groundwater ridging & & & \\ \hline \hline \end{tabular}
\end{table}
Table 1: Landforms, hydro-geomorphotypes and electrical conductivity ranges (modified from [4]).  
Figure 3: Expert-based hydro-geomorphological map of the catchment depicting the morphological units significant as hydro-geomorphotypes. In black, the hydrogeological features are as in Figure 2, and arrows represent the surveyed sub-surface flow.  
recorded as end-member signature at: permanent springs for the groundwater component, seasonal outlets of the zero-order basins for the subsurface flow component, soil pipes and gullies for the direct runoff component. In addition, shallow piezometers were located along the riparian corridor, lauses and the colluvial hollows. A summary of the monitored points with the collected parameters and time-steps is in Table 2.  
Since December 2015, water depth (D), discharge (Q), electrical conductivity (EC) and temperature (T) have been measured at five-minute intervals with the multi-parameter datalogger of the solution pressure transmitter and level sensor (STS) at the main monitoring station located at the catchment outlet (420 m a.s.l.).  
The daily Q, measured with a Swoffer 3000 current meter (Swoffer Inc., Sumner, WA, USA) since 2013, was used to calibrate the stage-discharge rating curve at the main station. The EC was measured continuously during the floods and on a daily basis during low-flow periods at the same station, using a multi-probe HI9828 (Hanna Instruments Inc., Romania, 1% errors) and was used to calibrate the continuous data detected with the STS data logger.  
For this study, only data obtained from the main station and from the 2015-2017 (Figure 4) hydrological years were analyzed, as they were of particular interest due to their brief rainy periods.