Evolution of surface deformation related to salt extraction-caused sinkholes in Solotvyno (Ukraine) revealed by Sentinel-1 radar interferometry

Abstract

<jats:p>Abstract. Rocksalt has remarkable mechanical properties and a high economic importance, however, this strength of salt compared to other rocks makes it a rather vulnerable material. Human activities could lead to acceleration of the dissolution of soluble rocksalt and collapse of subsurface caverns. Although sinkhole development can be considered local geological disaster regarding the characteristic size of surface depressions the deformations can result in catastrophic events. In this study we report the spatiotemporal evolution of surface deformation in Solotvyno salt mine area in Ukraine based on Sentinel-1 interferometric synthetic aperture radar measurements. Although the mining operations were finished in 2010 several sinkholes have been opened up since then. Our results show that even though the enormous risk managing efforts the sinkholes continue to expand with a maximum line-of-sight deformation rate of 5 cm/yr. The deformation time series show a rather linear feature and unfortunately no slowdown of the processes can be recognized based on the investigated 4.5 year-long data set. We utilized both ascending and descending satellite passes to discriminate the horizontal and vertical deformations and our results revealed that vertical deformation is much more dominant in the area. With the 6-day repetition time of Sentinel-1 observations the evolution of surface changes can be detected in quasi real-time which can facilitate disaster response and recovery. </jats:p>

Review on the Use of Satellite-Based Radar Interferometry for Monitoring Mining Subsidence in Urban Areas and Demographic Indicators Assessment

“…The SBAS concentrates on distributed scatterers, as they are more sensible to temporal and volume decorrelation than PSs [23]. SBAS technique was used for mining subsidence monitoring in [12][13][14]20,28,54].…”

“…iron mining in Rancourt, Lorraine, France [43], coal mining in Witbank Coalfields, South Africa [32], Athens Basin [51], South Limburg, Netherlands [50],  closed mines in the 1990s (e.g.Inowroclaw, Poland [47], South Derbyshire and Leicestershire, UK [62], Nord/Pas-e-Calais, France [25], Ocnele Mari, Romania [35], Campine Coal Basin, Belgium [16]),  closed mines after 2000 (e.g. salt mine in Poland [11][12][13]),  active mining sites (e.g. coal mine in Gardanne France [24], Rydultowy, Poland [28], Legnica Glogow Cooper Belt, Poland [46], New South Wales Australia coal mine [29,30], El Teniente, Chile [39,44], China [20,37,38,49])  mining sites with historical and active mines (e.g.…”

“…Athens Basin [51], Ocnele Mari, Romania [35], South Limburg, Netherlands [50], Inowrocław, Poland [47]), to centimetres (e.g. La Union, Spain [59,60], Cardona Salt mine, Spain [48], Karvina mine, Czech Republic [34], Solotvyno, Ukraine [11,12], Roncourt, France [43]), tens of centimetres (e.g. NW of Upper Silesian Coal Basin [22], Matjhabeng gold mine South Africa [73], N4W iron mine, Brazil [52]), and even meters (e.g.…”

“…In 4 of these studies, the precise levelling was used in combination with the GNSS field surveys. For one study the validation method was also SAR monitoring [12], from a study conducted on the same area, with data from the same SAR satellite mission and the same time interval [11]. For another study, the precise levelling was used as alternative method, in combination with the aerial photo interpretation [59].…”

“…Characteristics such as country, type of mining exploitation, status of the mining area when the SAR monitoring was performed, SAR monitoring technique, deformation rate, SAR monitoring period, SAR data used for mining subsidence monitoring, the alternative monitoring methods complementary used to InSAR methods. Considering the consulted scientific literature on this topic and the wide spread of different types of mining worldwide, it can be stated that in many cases the most challenging areas were chosen to be monitored, considering the accidents [10] or the complexity of the studied areas [11][12][13]. Long-term SAR monitoring analyses are also of interest, considering the open SAR data available since 1992 [14].…”