InSAR-Based Mapping of Tidal Inundation Extent and Amplitude in Louisiana Coastal Wetlands

The Louisiana coast is among the most productive coastal areas in the US and home to the largest coastal wetland area in the nation. However, Louisiana coastal wetlands have been disappearing at an alarming rate due to natural and anthropogenic processes, including sea level rise, land subsidence and infrastructure development. Wetland loss occurs mainly along the tidal zone, which varies in width and morphology along the Louisiana shoreline. In this study, we use Interferometric Synthetic Aperture Radar (InSAR) observations to detect the extent of the tidal inundation zone and evaluate the interaction between tidal currents and coastal wetlands. Our data consist of ALOS and Radarsat-1 observations acquired between 2006–2011 and 2003–2008, respectively. Interferometric processing of the data provides detailed maps of water level changes in the tidal zone, which are validated using sea level data from a tide gauge station. Our results indicate vertical tidal changes up to 30 cm and horizontal tidal flow limited to 5–15 km from open waters. The results also show that the tidal inundation is disrupted by various man-made structures, such as canals and roads, which change the natural tidal flow interaction with the coast

Land subsidence contribution to coastal flooding hazard in southeast Florida

Over the past decade, several coastal communities in southeast Florida have experienced a significant increase in flooding frequency, which has caused significant disturbance to property, commerce, and overall quality of life. The increased flooding frequency reflects the contribution of global, regional, and local processes that affect elevation difference between coastal communities and rising sea level. In a recent project, funded by the state of Florida, we monitor coastal subsidence in southeast Florida using GPS and InSAR observations, in order to evaluate the contribution of local subsidence to the increased coastal flooding hazard. Preliminary results reveal that subsidence occurs in localized patches (\u3c 0.02 km2) with magnitude of up to 3mmyr1, in urban areas built on reclaimed marshland. These results suggest that contribution of local land subsidence affect only small areas along the southeast Florida coast, but in those areas coastal flooding hazard is significantly higher compared to non-subsiding areas

InSAR detection of localized subsidence induced by sinkhole activity in suburban west-central Florida

Sinkhole activity in west-central Florida is a major hazard for people and property. Increasing frequency of sinkhole collapse is often related to an accelerated use of groundwater and land resources. In this work, we use radar interferometry acquired over a selected region in Hernando County in west-central Florida to observe small localized deformation possibly caused by sinkhole activity. The data used for the study consist of acquisitions from one TerraSAR-X frame covering a time span of approximately 1.7 years with spatial resolution of 0.25 by 0.60 m.We applied the Persistent Scatterer Interferometry (PSI) technique using the Stanford Method for Persistent Scatterers (StaMPS). Results reveal several areas of localized subsidence at rates ranging from -3:7 to -4:9mmyr-1. Ground truthing and background verification of the subsiding locations confirmed the relationship of the subsidence with sinkhole presence

Land subsidence and its relations with sinkhole activity in karapınar region, turkey: A multi-sensor insar time series study

The Karapinar basin, located in the Central Anatolian part of Turkey, is subjected to land subsidence and sinkhole activity due to extensive groundwater withdrawal that began in the early 2000s. In this study, we use Interferometric Synthetic Aperture Radar (InSAR), Global Navigation Satellite System (GNSS), and groundwater level data to monitor and better understand the relations between groundwater extraction, land subsidence, and sinkhole formation in the Karapinar basin. The main observations used in the study are InSAR-derived subsidence velocity maps calculated from both Sentinel-1 (2014–2018) and COSMO-SkyMed (2016–2017) SAR data. Our analysis reveals broad areas of subsidence with rates exceeding 70 mm/yr. The InSAR-derived subsidence was compared with GNSS data acquired by a continuously operating GNSS station located in the study area, which show a similar rate of subsidence. The temporal characteristic of both InSAR and GNSS time series indicate a long-term subsidence signal superimposed by seasonal variability, which follows the overall groundwater level changes, with over 80% cross-correlation consistency. Our results also indicate that sinkhole activity is limited to slow subsidence areas, reflecting strong cohesion of near-surface rock layers that resist subsidence but yield to collapse in response to aquifer system deformation induced by groundwater extraction

Land subsidence and its relations with sinkhole activity in karapınar region, turkey: A multi-sensor insar time series study

The Karapinar basin, located in the Central Anatolian part of Turkey, is subjected to land subsidence and sinkhole activity due to extensive groundwater withdrawal that began in the early 2000s. In this study, we use Interferometric Synthetic Aperture Radar (InSAR), Global Navigation Satellite System (GNSS), and groundwater level data to monitor and better understand the relations between groundwater extraction, land subsidence, and sinkhole formation in the Karapinar basin. The main observations used in the study are InSAR-derived subsidence velocity maps calculated from both Sentinel-1 (2014–2018) and COSMO-SkyMed (2016–2017) SAR data. Our analysis reveals broad areas of subsidence with rates exceeding 70 mm/yr. The InSAR-derived subsidence was compared with GNSS data acquired by a continuously operating GNSS station located in the study area, which show a similar rate of subsidence. The temporal characteristic of both InSAR and GNSS time series indicate a long-term subsidence signal superimposed by seasonal variability, which follows the overall groundwater level changes, with over 80% cross-correlation consistency. Our results also indicate that sinkhole activity is limited to slow subsidence areas, reflecting strong cohesion of near-surface rock layers that resist subsidence but yield to collapse in response to aquifer system deformation induced by groundwater extraction

InSAR-Based Mapping of Tidal Inundation Extent and Amplitude in Louisiana Coastal Wetlands

The Louisiana coast is among the most productive coastal areas in the US and home to the largest coastal wetland area in the nation. However, Louisiana coastal wetlands have been disappearing at an alarming rate due to natural and anthropogenic processes, including sea level rise, land subsidence and infrastructure development. Wetland loss occurs mainly along the tidal zone, which varies in width and morphology along the Louisiana shoreline. In this study, we use Interferometric Synthetic Aperture Radar (InSAR) observations to detect the extent of the tidal inundation zone and evaluate the interaction between tidal currents and coastal wetlands. Our data consist of ALOS and Radarsat-1 observations acquired between 2006–2011 and 2003–2008, respectively. Interferometric processing of the data provides detailed maps of water level changes in the tidal zone, which are validated using sea level data from a tide gauge station. Our results indicate vertical tidal changes up to 30 cm and horizontal tidal flow limited to 5–15 km from open waters. The results also show that the tidal inundation is disrupted by various man-made structures, such as canals and roads, which change the natural tidal flow interaction with the coast

Determinación de áreas protegidas Caso de Estudio: Sierra de Pénjamo, Gto.

Determinación de áreas protegidas Caso de Estudio: Sierra de Pénjamo, Gto

InSAR Applications for Environmental and Hazard Monitoring

As human sprawl extends, and the use of natural resources grows, changes in the surface of the Earth represent an increasing threat for human lives. Deformation in the Earth surface is driven by many different processes (e.g. anthropogenic changes). A better understanding of the behavior and magnitude of these movements may help to improve human life and risk assessment. This work explores Earth superficial deformation processes that happen in solid, ice or aquatic surfaces using radar interferometry technique to observe surface changes. Three different non-tectonic phenomena were selected: tidal flow inundation in coastal wetlands (Chapter 3), precursory sinkhole movements in suburban areas (Chapter 4), and permafrost change and loss (Chapter 5). Results show great capability of the technique detecting the diverse rates of deformation from each chosen site. Water level changes of 24 cm and tidal inundation extents of up to 20 km were detected in the coast of Louisiana. Deformation due to possible sinkhole was observed with rates reaching -20 mm/yr in houses located in Florida and permafrost surface changes ranging +/- 1.4cm/yr were observed in the region of the Mackenzie river delta in Canada

Monitoring and Modeling of Sinkhole-Related Subsidence in West-Central Florida Mapped from InSAR and Surface Observations

Sinkholes in Florida cause millions of dollars in damage to infrastructure each year. Methods of early detection of sinkhole-related subsidence are clearly desirable. We have completed two years of monitoring of selected sinkhole-prone areas in west central Florida with XXX data and analysis with XXX algorithms. Filters for selecting targets with high signal-to-noise ratio and subsidence over this time window (XX-2015-XX-2017) are being used to select sites for ground study. A subset of the buildings with InSAR-detected subsidence indicated show clear structural indications of subsidence in the form of cracks in walls and roofs. Comsol Multiphysics models have been developed to describe subsidence at the rates identified from the InSAR analysis (a few mm/year) and on spatial scales observed from surface observations, including structural deformation of buildings and ground penetrating radar images of subsurface deformation (length scales of meters to tens of meters). These models assume cylindrical symmetry and deformation of elastic and poroelastic layers over a growing sphering void

Monitoring and Modeling of Sinkhole-Related Subsidence in West-Central Florida Mapped from InSAR and Surface Observations

Sinkholes in Florida cause millions of dollars in damage to infrastructure each year. Methods of early detection of sinkhole-related subsidence are clearly desirable. We have completed two years of monitoring of selected sinkhole-prone areas in west central Florida with XXX data and analysis with XXX algorithms. Filters for selecting targets with high signal-to-noise ratio and subsidence over this time window (XX-2015-XX-2017) are being used to select sites for ground study. A subset of the buildings with InSAR-detected subsidence indicated show clear structural indications of subsidence in the form of cracks in walls and roofs. Comsol Multiphysics models have been developed to describe subsidence at the rates identified from the InSAR analysis (a few mm/year) and on spatial scales observed from surface observations, including structural deformation of buildings and ground penetrating radar images of subsurface deformation (length scales of meters to tens of meters). These models assume cylindrical symmetry and deformation of elastic and poroelastic layers over a growing sphering void