# Review of Works Combining GNSS and InSAR in Europe
## 3 Temporal and Spatial Distribution of Scientific Production in Europe
### Field of Application  
The joint application of SAR and GNSS data has been adopted in 9 different fields, classified as follows: (i) Tectonic; (ii) Atmosphere; (iii) Glacial; (iv) Volcanic; (v) Subsidence; (vi) Landslide; (vii) Infrastructure; (viii) Subsidence/Uplift; and ix) Uplift. In addition, another class has been added to include all nonconventional applications, as well as a Not Specialized class (N.S.) for applications in which it was not possible to assign a specific field. A higher percentage of publications deal with subsidence phenomena (20.2%), followed by landslide events (19.7%) and tectonic analyses or seismic event back analyses (18.6%) (Figure 4). Subsidence phenomena are spatially distributed in Europe, with a higher concentration of studies (i) in the Upper Rhine Graben, at the boundary between France and Germany [92; 93; 94; 62]; (ii) in Italy, over the Pianura Padana Plain (central Italy), in the Emilia Romagna Region [44; 47; 48] and the areas of the Po Plain [20; 45; 49; 95; 96], in the Venice lagoon [41; 43; 97; 98], in the Friuli Venezia Giulia coastal plain (North-East of Italy) [99], the Firenze-Prato-Pistoia basin (Tuscany Region, central Italy) [100], and the Sibari plain (Calabria Region, South Italy) [101]; and (iii) in Spain, the Alto Guadalentin [102; 103] (South-East of Spain), in Lorca town [54] and in the Cardona salt mine [60] (North-East of Spain). In Portugal, instead, only two scientific contributions have been reported in connection to the subsiding area of Lisbon [70; 104]. Eastern Europe shows a widespread distribution of land subsidence issues, which have been analyzed by combining GNSS and InSAR data, in the coastal portion of Lithuania, close to Kaszuby Lakeland [105], in the agglomeration of Warsaw, Poland [106], in the Bucharest metropolitan area in Romania [107; 108], and close to the Tatra Mountains in Slovakia [109]. A specific focus on mining-induced land subsidence events and collapses was provided by research which studied the Upper Silesia Coal basin, covering a part of the territory of Poland [110] and the Czech Republic [111]. North Europe is represented only by the surface motion of peatland in Flow County, Scotland [112], and the localized ground subsidence in the urban settings of London [113] for the United Kingdom and the analysis in the prediction of long-term settlement in the Trondheim harbor, mid-Norway [76]. Figure 3: Temporal evolution of the scientific contributions combining GNSS and InSAR data in Europe considering the field of application. A more widespread distribution of scientific contributions from landslide studies with the joint application of GNSS and SAR data can be observed in Europe. A total of 14 nations have at least one reported application. The country with the highest number of contributions is Norway, represented by the cases of the Aknes landslide [114], the Gamanjunni rock slope [78], the Osmundneset landslide in Sognog Fjordane [115], the periglacial landscape activity at Nordnesfjellet [116], and the mapping [79] and monitoring [80] of landslides in North and West Norway. Norway is followed by Switzerland, with 6 contributions, including 3 peer reviewed articles in international journals and 3 proceedings, which focused on rock glacier detection and monitoring [117; 118], slope instability monitoring events in the Western Alps [119; 120], and deep-seated landslide recognition by Osco [121] and Aletsch Forest [122]. The third most represented country is Italy, with 5 peer-reviewed articles and a proceeding focus on specific case studies of the Bosmatto landslides in the Northwestern Alps [39], investigations over the wider area of the Northern Apennines [123], and of the Assisi landslides [23; 52], in addition to a quantitative hazard and risk assessment of slow-moving landslides in the Arno Basin in Tuscany [124].