## 6 Discussion  
The present availability and free access of Sentinel satellites data allow producing costless and rapid data with high spatial and temporal resolutions for surface water mapping on wide areas. The advances in managing such remotely-sensed satellite data have led to the development of various near real-time, semi-automated flood mapping algorithms [31; 35]. As a result, Sentinel-1 and Sentinel-2 satellite imagery can easily support and provide useful information during an emergency or calibrate and validate hydrodynamic models during ordinary time, enhancing stakeholders understanding and accurate mapping of flood extents for environmental planning strategies [36; 37; 38]. The optical data are easily accessible and exploitable through the EO Browser platform ([[https://apps.sentinel-hub.com/eo-browser/](https://apps.sentinel-hub.com/eo-browser/)]([https://apps.sentinel-hub.com/eo-browser/](https://apps.sentinel-hub.com/eo-browser/))) that allows basic processing. Nevertheless, the interpretation has to be carried out by expert users in order to consider the limitations of the data (e.g., cloudy scenes) and to avoid misunderstanding. Also, the radar data can be freely downloaded and quickly processed by user-friendly free software, but expert-knowledge and specific software is needed for an in-depth interpretation. The validation of our outputs performed by comparing the satellite data with official Copernicus EMS map on the 11 March 2018 flood event shows good accordance results. It is worth to highlight that in our proposed methodology no refinement was applied to the SNAP processing as an overall overview was obtained at large scale. Conversely, a more accurate result could be obtained by performing post-processing edit to further refine the inundation areas at a more detailed scale such as supervised classification to filter out isolated flood elements, to remove possible water-lookalikes and to weed out false positives. Furthermore, in order to distinguish inundated areas from permanent water bodies related to the usual water level of the lake and the river, a reference \"water mask\" could be applied, for instance by using SWBD (SRTM water body data) source. Nevertheless, the results of this work show that the 1 December 2017 event has the minimum extension, as only scattered fields closest to the coastline, are submerged by a water sheet (with a spatial increase towards south) and none of the informal areas seems to be directly impacted by the event. On the contrary, the 5 March  
Figure 8: **(a)** COPERNICUS Emergency Management Service (EMS) delineation map: Situation as of 18 March 2018 (activation ID EMS273); **(b)** rapid flood map as binary water mask based on Sentinel-1 radar image acquired on 11 March 2018, overlapped on EMS Delineation map displayed in (1). 2018 and 11 March 2018 events affected many natural vegetated areas and open spaces reserved for livestock farming (mainly cattle) covering most of the Ramsar protected area. Moreover, these last two events affected the informal area n\({}^{\circ}\) 6 in the topographically lower coastal areas and reached the south-west border of the informal area n\({}^{\circ}\) 2. In both cases, floods were due to the combination of the rapid rise of the lake level with the insufficient drainage capacity of the Buna river; the downstream hydrographic node was crucial in relation to the contingent hydraulic conditions, through which the lake waters have to be necessarily disposed of. However, in these occasions the more careful management of water flows passing through the upstream dams along the Drin river with respect to the past (e.g., contrary to the 2010 mismanagement) allowed to contain the water level, to limit the flooding expansion and to reduce the impact in the coastal urban areas.