Disappearing cities on US coasts

The sea level along the US coastlines is projected to rise by 0.25–0.3 m by 2050, increasing the probability of more destructive flooding and inundation in major cities1,2,3. However, these impacts may be exacerbated by coastal subsidence—the sinking of coastal land areas4—a factor that is often underrepresented in coastal-management policies and long-term urban planning2,5. In this study, we combine high-resolution vertical land motion (that is, raising or lowering of land) and elevation datasets with projections of sea-level rise to quantify the potential inundated areas in 32 major US coastal cities. Here we show that, even when considering the current coastal-defence structures, further land area of between 1,006 and 1,389 km2 is threatened by relative sea-level rise by 2050, posing a threat to a population of 55,000–273,000 people and 31,000–171,000 properties. Our analysis shows that not accounting for spatially variable land subsidence within the cities may lead to inaccurate projections of expected exposure. These potential consequences show the scale of the adaptation challenge, which is not appreciated in most US coastal cities

Satellite Techniques: New Perspectives for the Monitoring of Dams

Dam deformation detection, analysis, and monitoring represent a growing issue for a large part of commercial companies and research groups at national and international levels. Although dam failures are usually sudden, in the majority of cases it is possible to predict when structural damage conditions might become serious

Supplementary tables for Disappearing Cities on US Coasts

This dataset contains supporting materials supporting "Disappearing Cities on US coasts".</p

Radar remote sensing from space for surface deformation analysis: present and future opportunities from the new SAR sensor generation

This paper discusses, through two selected case studies based on real data, how the availability of the new generation of Synthetic Aperture Radar (SAR) sensors, characterized by reduced revisiting time and improved spatial resolution or coverage, is impacting the exploitation of Differential SAR Interferometry (DInSAR) techniques for the detection and monitoring of deformation phenomena. The presented analysis is carried out using X-band data of the COSMO-SkyMed constellation satellites, as well as C-band data acquired by the Sentinel-1A sensor; furthermore, we compare the achieved results to those based on first-generation ERS-1/2 and ENVISAT satellite data. The first case study shows how the COSMO-SkyMed X-band SAR systems open new opportunities for the detection and monitoring of deformation phenomena at the scale of a single building, even when they are characterized by a rather fast dynamic. The second experiment is based on the Sentinel-1A DInSAR measurements and permits us to envisage new scenarios for deformation analysis of very wide areas. The final discussion is devoted to summarise the lessons learned through the presented case studies and to identify the main future actions needed for a full exploitation of the surface deformation measurement capability provided by the new generation of SAR senso

On the joint exploitation of long-term DInSAR time series and geological information for the investigation of ground settlements in the town of Roma (Italy)

In this work the long-term DInSAR deformation time series have been jointly exploited with the geological information and the structural characteristics of the buildings, in order to study the interactions between the soils and the man-made structures and to investigate the response of different buildings to the settlements. The presented analysis has been carried out by applying the advanced multi-temporal DInSAR technique referred to as Small BAseline Subset (SBAS) approach to an ERS/ENVISAT SAR dataset, collected over the town of Roma (Italy) in the 1992-2010 time interval. Our study has been performed first at the large spatial scale, and then at the local scale, focusing on some buildings located within the city centre on the eastern side of the Tevere River. The obtained SBAS-DInSAR measurements, analysed in light of the geological setting and the spatial distribution of the settlements, indicate that the observed displacements are mainly linked to a residual consolidation process, correlated with the urbanization and hydrometric level of the Tevere River. The local variation in the deformation rates can be related to the intrinsic variability of the soils filling the alluvial valley and to time since loading application

Recent sightings of marine mammals in Andaman Islands, India

This study reports opportunistic sightings of marine mammals between August 2013 and January 2014 in the Andaman region.  Seven sightings were recorded during this period out of which one was of a Dugong, which is significant considering its small population size in India and limited data on its distribution and abundance.  The rest were 24 dolphins (Tursiops sp.).  Four sightings were of the same pod of dolphins on different days at the same location.  Two sightings occurred during regular coral reef monitoring survey and the other five during fishery resource survey by trawling operations.  These sightings are of great significance as there is a lack of studies on marine mammals from the region.  Sighting records are useful for understanding aggregation site, behaviour, habits and habitat and residency patterns and provide important information for conservation of marine mammals. </div

UNSUPERVISED PARALLEL SBAS-DINSAR CHAIN FOR MASSIVE AND SYSTEMATIC SENTINEL-1 DATA PROCESSING

In this work we present an efficient interferometric processing chain, based on the advanced DInSAR algorithm referred to as Parallel Small BAseline Subset (P-SBAS), for the generation of Sentinel-1A (S1A) Interferometric Wide Swath deformation time-series, which is able to exploit distributed computing architectures. The presented S1A P-SBAS processing chain has been successfully implemented within the ESA Geohazard Exploitation Platform to provide an on-demand automatic service for the unsupervised generation of P-SBAS displacement time-series. To give an idea of the effectiveness of the presented S1A processing chain, as a preliminary result we show a 12-days interferometric analysis at continental scale, carried out by exploiting 150 S1A interferometric pairs acquired over Europe for an overall covered area of about 7,500,000 km2

Quantifying the effects of ground settlement on buildings by the exploitation of long term DINSAR time series. The case of Roma

Differential Synthetic Aperture Radar Interferometry (DInSAR) is a well-established remote sensing methodology aimed at the analysis and monitoring of displacements due to the ground settlement or to the deformations of the structures. Among the DInSAR techniques, the Small BAseline Subset (SBAS) approach, working at different scales of investigations, permits to detect and control the deformation processes that may involve structures and infrastructures in urban areas. This work is focused on the exploitation of the results obtained by applying Small Baseline Subset (SBAS) technique of high resolution DInSAR analysis applied to ENVISAT and COSMO-SkyMed data. The DInSAR products (average velocity maps and time series of displacements) are adopted to implement and test a processing architecture to investigate the stability of built-up areas at regional and local scales