In this work we present some applications of Ground-Based Synthetic Aperture Radar (GBSAR) interferometry to the monitoring of dams, bridges and landslides. A SAR system is a coherent active microwave device able to provide 2D... more
In this work we present some applications of Ground-Based Synthetic Aperture Radar (GBSAR) interferometry to the monitoring of dams, bridges and landslides. A SAR system is a coherent active microwave device able to provide 2D refractivity images of a given area with high spatial resolution, independently of weather conditions and day-night cycle. SAR interferometry is the most notable application of SAR technology. This technique relies on the processing of a time series of coherent SAR images. It gives a powerful tool to produce maps of deformations occurring in infrastructures (dams, buildings, bridges) or terrain. In the last few years the research activity of several remote sensing groups has dealt with the development of GBSAR systems. GBSAR sensors represent a cost-effective solution for the continuous monitoring of small scale deformation phenomena if compared to space and air-borne systems. These systems basically consist of a CW radar mounted on a sliding support and synth...
GB InSAR technique plays an increasingly important role in determining the deformation of dams. The paper describes the use of GB InSAR technique for monitoring deformations of the Czech largest concrete dam Orlik on the Vltava river.... more
GB InSAR technique plays an increasingly important role in determining the deformation of dams. The paper describes the use of GB InSAR technique for monitoring deformations of the Czech largest concrete dam Orlik on the Vltava river. After analyzing one month-long continuous measurement of the dam were detected non-linear movements. The relation between acting water level and resulting deformations were investigated in detail. The results confirm that GB InSAR technique is very suitable for monitoring deformations of this type of constructions. At the same time, the results may serve as a valuable source of data and information for further analysis in area of stability and for early warning systems.
Since the impoundment of the Three Gorges Reservoir (TGR) in June 2003, the fluctuation of the reservoir water level coupled with rainfall has resulted in more than 2500 landslides in this region. Among these instability problems, most... more
Since the impoundment of the Three Gorges Reservoir (TGR) in June 2003, the fluctuation of the reservoir water level coupled with rainfall has resulted in more than 2500 landslides in this region. Among these instability problems, most colluvial landslides exhibit slow-moving patterns and pose a significant threat to local people and channel navigation. Advanced monitoring techniques are therefore implemented to investigate landslide deformation and provide insights for the subsequent countermeasures. In this study, the development pattern of a large colluvial landslide, locally named the Ganjingzi landslide, is analyzed on the basis of long-term monitoring. To understand the kinematic characteristics of the landslide, an integrated analysis based on real-time and multi-source monitoring, including the global navigation satellite system (GNSS), crackmeters, inclinometers, and piezometers, was conducted. The results indicate that the Ganjingzi landslide exhibits a time-variable respo...
From a geological standpoint, northern Pakistan is one of the most active and unstable areas in the world. As a consequence, many massive landslides have occurred in the area in historical times that have destroyed infrastructure, blocked... more
From a geological standpoint, northern Pakistan is one of the most active and unstable areas in the world. As a consequence, many massive landslides have occurred in the area in historical times that have destroyed infrastructure, blocked the Hunza River, and damaged the Karakoram Highway repeatedly. However, despite the high frequency of large magnitude landslide events, and the consequent damages, the entire area is largely understudied, mainly due to the difficult logistics and the large distances involved. This work is aimed at applying the potential use of Interferometric Synthetic Aperture Radar (InSAR) for landslide identification and investigation for the Hunza-Nagar Region. Sentinel-1 images covering a period of more than two years (February 2017–August 2019) were used and processed by adopting the small baseline subset (SBAS) method. The obtained deformation rate measured along the line of sight (VLOS) varies from −114 to 20 mm/year. The downslope velocity deformation rate...
Slow moving landslide is a major disaster in the Three Gorges Reservoir area. It is difficult to compare the deformation among different parts of this kind of landslide through GPS measurements when the displacement of different... more
Slow moving landslide is a major disaster in the Three Gorges Reservoir area. It is difficult to compare the deformation among different parts of this kind of landslide through GPS measurements when the displacement of different monitoring points is similar in values. So far, studies have been seldom carried out to find out the information hidden behind those GPS monitoring data to solve this problem. Therefore, in this study, three landslides were chosen to perform landslide displacement analysis based on fractal theory. The major advantage of this study is that it has not only considered the values of the displacement of those GPS monitoring points, but also considered the moving traces of them. This allows to reveal more information from GPS measurements and to obtain a broader understanding of the deformation history on different parts of a unique landslide, especially for slow moving landslides. The results proved that using the fractal dimension as an indicator is reliable to estimate the deformation of each landslide and to represent landslide deformation on both spatial and temporal scales. The results of this study could make sense to those working on landslide hazard and risk assessment and land use planning.
The Three Gorges occupy 193 km of the middle reaches of the Yangtze River between Fengjie in Chongqing and Yichang in Hubei Province, China. Due to steep valley-side slopes and long-term river incision, landslides are a major hazard in... more
The Three Gorges occupy 193 km of the middle reaches of the Yangtze River between Fengjie in Chongqing and Yichang in Hubei Province, China. Due to steep valley-side slopes and long-term river incision, landslides are a major hazard in the Three Gorges region. In this study, we employ the SBAS InSAR technique to process Envisat SAR images collected between 2003 and 2010. Our time series results enable identification of two distinct landslides with deformation rates of up to 10–15 mm/yr in Badong County, and field evidence is used to verify the positions of these failures. With both descending and ascending observations, two-dimensional velocity fields in north and up directions are recovered to better understand the landslide movements. Obvious correlation between seasonal landslide movements and water level changes is observed, which not only provides strong support of our InSAR time series results, but also indicates the impacts of water level changes to landslide activities.► Small baseline time series InSAR technique used for 3 different tracks. ► Consistent movement trends from 3 tracks to identify two distinct landslide fields. ► Two-dimensional velocity fields recovered. ► Correlation between seasonal landslide movements and water level changes is observed.
