# Multitemporal SAR Data and 2D Hydrodynamic Model Flood Scenario Dynamics Assessment
## 2 The Bradano River Case Study and the Available Dataset  
The study was carried out on a flat area of about 80 km\({}^{2}\) in the Basilicata Region (Southern Italy), stretching for 8 km upstream of the mouth of the Bradano River (Figure 1). The surrounding land cover is mainly agricultural, characterized by cereal and vegetable crops or orchards, while an extended area near the river mouth and along the coast is occupied by pinewoods. Moreover, several residential buildings and agricultural enterprises are located in the floodplains, with quite a few tourist resorts near the basin outlet (i.e., along the coast). When considering that the mouth of the Bradano River is at high risk of flooding due to its intrinsic lithological and geomorphological properties [27], and that this location is advantageous for human population development in many perspectives, urban development occurred over time, along with construction of several structural mitigation measures (levees and banks, but also artificial hills and bridges), rendering the topography of the area extremely complex. Despite many efforts to protect against inundations in this area, several flood events have occurred recently, with increasing consequences for agriculture, industries and dwellings [28]. In this study, we focus on two such recent events, which took place, respectively, on 3-4 November 2010 and 2-3 December 2013. As part of an agreement with the University of Basilicata's PhD School for Engineering for Innovation and Sustainable Development, the ASI (Italian Space Agency) provided the authors with a set of Cosmo-SkyMed (CSK) observations for these two flood events (Single-look Complex Slant products: SLC), performed in Stripmap mode with a resolution of 2.5 m and are characterized by horizontal or vertical polarization. In addition, two archive images (of the same type in terms of polarization and orbit) of the same area, acquired in the weeks before each of the two events occurred, were made available by the ASI to be used as a benchmark. Thus, three SAR images were available for each event: the first image recorded a few weeks before the event, used in the study as a benchmark for flood extent detection analysis, and two images acquired during the event, respectively, near peak flow and in the recession stage of the flood event (see Table 1). In particular, during the November 2010 event, peak flow was recorded in the early morning of 3 November, with discharge reaching about 700 m\({}^{3}\)/s. The considered event was triggered by an amount of rainfall that reached about 63 mm in one day (measured at the Matera gauging station upstream of the study area), causing damage to the residential and agricultural sectors, tourist resorts, and the main railway in the Taranto-Reggio Calabria stretch, which became unusable due to water and mud. During the December 2013 event, peak flow was recorded in the early hours of 2 December, with discharge reaching about 800 m\({}^{3}\)/s. The event considered was triggered by a significant amount of rainfall that reached about 100 mm in one day (measured at the Matera city gauging station upstream of the study area), while the total amount of rainfall reached about 120 mm. In particular, as officially reported by Basilicata Regional Civil Protection, the Bradano River flooded, impacting large areas that were concentrated along the riverbanks, leading to closure of the S.S. 106 Jonica A-road, namely one \begin{table}
\begin{tabular}{c c c} \hline \hline
**Acquisition Time** & **Polarization** & **Orbit** \\ \hline
10 October 2010 & 4:47 a.m. & VV 1  & RA 1  \\
3 November 2010 & 4:47 a.m. & VV & RA \\
4 November 2010 & 4:47 a.m. & VV & RA \\
16 November 2013 & 4:31 a.m. & HH 1  & RA \\
2 December 2013 & 4:31 a.m. & HH & RA \\
3 December 2013 & 4:31 a.m. & HH & RA \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Characteristics of the Cosmo-SkyMed (CSK) observations provided by the Italian Space Agency (ASI). Figure 1: The Bradano River mouth case study.