# Hydrodynamic Modelling in a Mediterranean Coastal Lagoon--The Case of the Stagnone Lagoon, Marsala
## 2 Materials and Methods
### Field Data  
The model has been used referring to two different field campaigns, using different measuring instruments. The first field campaign occurred during the first week of July 2006, and the other one during the last week of July 2007. During both, the free-surface level in the southern mouth (SM) was obtained through a pressure sensor (Valeport 808 EM). The pressure was recorded every 2 min (Table 1). The water elevation at the northern mouth (NM) was registered using a float-operated shaft encoder (Ott Thalimedes), located in a box connected to the dredged channel of the north mouth, as reported in Figure 3. The sea level was measured every minute, while the mean value was recorded every 5 min (Table 1). The water velocity was measured in three stations inside the lagoon. In the stations Adv and Vec, two ultrasound current meters of Nortek (Adv and Vector) were deployed (Figure 3). By means of these velocimeters, it is possible to acquire the three-dimensional velocity components with a sampling rate of up to 25 Hz. The measured velocity refers to a single point, with a sampling volume diameter of about 10 mm. The third current meter is the Val (Valeport 808 EM), which is an electromagnetic velocimeter, with a minimum sampling rate of 2 s (0.5 Hz). In the Vector and Valeport, a pressure sensor measures the level oscillation of the free surface. Velocity measurements were placed at 65% of the mean water depth, counting from the bottom, in order to take into account the influence of the submerged vegetation's ability to damp the water velocity inside the canopy [22]. To retrieve representative values of the velocity profile in all directions, we suppose that the vertical velocity profile above the canopy follows a logarithmic profile, as found by [23]. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & & \multicolumn{3}{c}{**Instruments Characteristics and Acquiring Period**} \\ \hline \multirow{2}{*}{**Station**} & \multirow{2}{*}{**Instrument**} & \multirow{2}{*}{**Measure**} & \multirow{2}{*}{**Period (s)**} & \multicolumn{2}{c}{**Mean Water Depth (m)**} & \multirow{2}{*}{**Starting Time**} & \multirow{2}{*}{**Ending Time**} \\ \hline \multirow{2}{*}{South Mouth (SM)} & \multirow{2}{*}{Valeport 808 EM} & \multirow{2}{*}{Pressure} & \multirow{2}{*}{120} & \multirow{2}{*}{0.60} & 04/07/2006 \(\pm\)17 & 09/07/2006 \(\pm\)745 \\  & & & & & 23/07/2007 17:54 & 27/07/2007 12:12 \\ \hline \multirow{2}{*}{Vec 06} & \multirow{2}{*}{Vector} & Pressure & 60 & & \\  & & Velocity & 60 & 1.30 & 05/07/2006 10:05 & 09/07/2006 \(\pm\)700 \\  & & & Wind & 60 & & \\ \hline Adv 06 & \multirow{2}{*}{Nortek ADV} & Velocity & 5 & 1.25 & 08/07/2006 8:43 & 09/07/2006 00:00 \\ \hline Val 06 & \multirow{2}{*}{Valeport 808 EM} & Pressure & 20 & & & \\  & & Velocity & 20 & 1.25 & 04/07/2006 14:45 & 09/07/2006 8:22 \\ \hline North Mouth (NM) & \multirow{2}{*}{Ott Thalimedes} & Level & 300 & 0.60 & \multicolumn{2}{c}{Always recording} \\ \hline \multirow{2}{*}{Vec 07} & \multirow{2}{*}{Vector} & Pressure & 10 & & \\  & & Velocity & 10 & 1.50 & 23/07/2007 18:35 & 27/07/2007 11:00 \\ \hline Adv 07 & \multirow{2}{*}{Nortek ADV} & Velocity & 10 & & & \\  & & LSI Lastem & Wind & 5 & 1.30 & 24/07/2007 11:04 & 27/07/2007 00:41 \\ \hline Val 07 & \multirow{2}{*}{Valeport 808 EM} & Pressure & 20 & & & \\  & & Velocity & 20 & 1.00 & 24/07/2007 08:16 & 27/07/2007 10:19 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Instruments characteristics. Figure 3: Localization scheme during the 2006 and 2007 field campaigns. Colours indicate the instrument type. The wind stations (Aanderaa Instruments for the 2006 campaign and LSI Lasten for the 2007 one) were both located 3 m above sea level. The locations of the recording stations deployed during the 2006 and 2007 campaigns are shown in Figure 3.  
A short measurement sketch (20 s) by Adv_07 at 20 Hz shows the characteristic orbital motion due to the wind waves [24] (Figure 4).