# EGMStream Webapp: EGMS Data Downstream Solution
## 3 Results
Additionally,  
Figure 4: Visualisation of the EGMS products, converted using the webapp and displayed through a GIS platform, for different areas of interest affected by various geohazards, both anthropogenic and natural: (**i**) the volcanic area of Campi Flegrei, Gulf of Naples (Italy); (**ii**) the landslide in the southern Serfjorden, Tromse municipality (Norway); (**iii**) the subsiding area of Firenze-Prato-Pistoia basin (central Italy); (**iv**) the Rules Dam and Reservoir, Granada province (Spain); (**v**) the archaeological site of Solnitsata-Provadia, Varna province (Bulgaria); (**vi**) the mining subsidence in the Upper Silesian Coal Basin (Czech Republic); (**vii**) the 2021 Larissa earthquake, Thessaly region (Greece). For the cases of southern Serfjorden and the Larissa earthquake, time series are shown for the points marked with black circles. a relevant subsidence bowl, reaching a vertical velocity of approximately \(-49\) mm/year, is evident in the eastern central portion of the basin due to the groundwater overexploitation in the industrial area of the Montemurlo municipality [92]. Outside these two areas, InSAR data show general stability, with only a few localised uplift zones exceeding the stable range by a few mm/year. L2A data were investigated over the Rules Dam and Reservoir to identify and monitor the ongoing deformation (Figure 4 iv). Ground deformation maps from both ascending and descending datasets reveal an area on the left flank with velocities of approximately \(-30\) mm/year and \(10\) mm/year, respectively. Additionally, deformation patterns in the northern branch appear in single geometries due to the combination of slope exposure and LoS orientation, requiring further investigation. The InSAR velocity components recorded over the archaeological site of Solnitsas-Provadia for the period 2019-2023 show a radial vertical subsiding displacement from approximately \(-10\) mm/year in the external part to \(-37\) mm/year in the centre. Meanwhile, the horizontal component exhibits positive values up to \(19\) mm/year in the eastern portion and negative values of around \(-13\) mm/year in the western one (Figure 4v). The time series of displacement in both components shows a linear trend with no acceleration or decelerations. Mining-induced subsidence in the Upper Silesian Coal Basin shows vertical displacement reaching approximately \(200\) mm in the period 2018-2022, with velocities up to \(48\) mm/year. Due to land cover and land use conditions, InSAR data coverage is not continuous across the entire area. Several circular-shaped subsidence bowls with peak displacements at their centres have been identified (Figure 4 vi). L2A data from the Larissa earthquake show clear displacements in both ascending and descending datasets. In the ascending datasets, there is a clear transition from positive to negative values moving from west to east, while in descending ones, the pattern is reversed. A notable feature in the time series is a clear discontinuity coinciding with the occurrence of earthquakes (Figure 4 vii). The EGMSream webapp offers a solid foundation for in-depth spatial and temporal analysis while greatly simplifying the integration and administration of converted data within GIS or WebGIS systems. Stress tests conducted on a Dell server equipped with a 20-core Xeon CPU and 512 GB of RAM have demonstrated that the application is capable of simultaneously handling over five active users without a notable impact on performance. A series of tests were conducted to verify the reliability and speed of the study. Table 1 reports the time required for downloading data of the samples area shown in Figure 4. For each area, the table indicates the format to which the downloaded data were converted, the EGMS product requested, and the spatial extent of the area. The reported times refer to both the download and conversion processes performed via the EGMSream webapp and the dedicated server.