An official website of the United States government
The 2023 Kahramanmaraş earthquake sequence produced extensive liquefaction-induced ground deformations and ongoing flooding along the shoreline of the Mediterranean port city of İskenderun, Türkiye. This study compiles field observations and analyses from cross-disciplinary perspectives to investigate whether earthquake-induced liquefaction was a significant factor for increasing the flood hazard in İskenderun. Geotechnical reconnaissance observations following the earthquakes included seaward lateral spreading, settlement beneath buildings, and failures of coastal infrastructure. Three presented lateral spreading case histories indicate consistent ground deformation patterns with areas of reclaimed land. Persistent scatterer interferometry (PSI) measurements from synthetic aperture radar (SAR) imagery identify a noticeably greater rate of pre- and post-earthquake subsidence within the İskenderun coastal and urban areas relative to the surrounding regions. The PSI measurements also indicate subsidence rates accelerated following the earthquakes and were typically highest near the observed liquefaction manifestations. These evaluations suggest that while the liquefaction of coastal reclaimed fill caused significant ground deformations in the shoreline area, ongoing subsidence of İskenderun and other factors likely also exacerbated the flood hazard. Insights from this work suggest the importance of evaluating multi-hazard liquefaction and flood consequences for enhancing the resilience of coastal cities.
more »
« less
Estimating Land Subsidence in Relation to Urban Expansion in Semarang City, Indonesia, Using InSAR and Optical Change Detection Methods
Land subsidence and flooding events in coastal Semarang City, Central Java, has had severe impacts on the region's population and economy. This work presents a methodology based on a combination of InSAR subsidence mapping and optical classification and change detection techniques to estimate the spatial distribution of subsidence rate and assess its impact on urbanization growth, land conversion and coastal flooding. Significant spatial relationships were found between urban zones (building density), flood extent (shoreline retreat) and subsidence rates. The overexploitation of aquifers and city zoning development contribute to accelerate subsidence rates.
more »
« less
- Award ID(s):
- 1827024
- PAR ID:
- 10195818
- Date Published:
- Journal Name:
- IGARSS 2019 - 2019 IEEE International Geoscience and Remote Sensing Symposium
- Page Range / eLocation ID:
- 9686 to 9689
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
Climate-driven sea-level rise is increasing the frequency of coastal flooding worldwide, exacerbated locally by factors like land subsidence from groundwater and resource extraction. However, a process rarely considered in future sea-level rise scenarios is sudden (over minutes) land subsidence associated with great (>M8) earthquakes, which can exceed 1 m. Along the Washington, Oregon, and northern California coasts, the next great Cascadia subduction zone earthquake could cause up to 2 m of sudden coastal subsidence, dramatically raising sea level, expanding floodplains, and increasing the flood risk to local communities. Here, we quantify the potential expansion of the 1 % floodplain (i.e., the area with an annual flood risk of 1%) under low (~0.5 m), medium (~1 m), and high (~2 m) earthquake-driven subsidence scenarios at 24 Cascadia estuaries. If a great earthquake occurred today, floodplains could expand by 90 km² (low), 160 km² (medium), or 300 km² (high subsidence), more than doubling the flooding exposure of residents, structures, and roads under the high subsidence scenario. By 2100, when climate-driven sea-level rise will compound the hazard, a great earthquake could expand floodplains by 170 km² (low), 240 km² (medium), or 370 km² (high subsidence), more than tripling the flooding exposure of residents, structures, and roads under the high subsidence scenario compared to the 2023 floodplain. Our findings can support decision makers and coastal communities along the Cascadia subduction zone as they prepare for compound hazards from earthquake-cycle and climate-driven sea-level rise, and provide critical insights for tectonically active coastlines globally.more » « less
-
Climate-driven sea-level rise is increasing the frequency of coastal flooding worldwide, exacerbated locally by factors like land subsidence from groundwater and resource extraction. However, a process rarely considered in future sea-level rise scenarios is sudden (over minutes) land subsidence associated with great (>M8) earthquakes, which can exceed 1 m. Along the Washington, Oregon, and northern California coasts, the next great Cascadia subduction zone earthquake could cause up to 2 m of sudden coastal subsidence, dramatically raising sea level, expanding floodplains, and increasing the flood risk to local communities. Here, we quantify the potential expansion of the 1% floodplain (i.e., the area with an annual flood risk of 1%) under low (~0.5 m), medium (~1 m), and high (~2 m) earthquake-driven subsidence scenarios at 24 Cascadia estuaries. If a great earthquake occurred today, floodplains could expand by 90 km2(low), 160 km2(medium), or 300 km2(high subsidence), more than doubling the flooding exposure of residents, structures, and roads under the high subsidence scenario. By 2100, when climate-driven sea-level rise will compound the hazard, a great earthquake could expand floodplains by 170 km2(low), 240 km2(medium), or 370 km2(high subsidence), more than tripling the flooding exposure of residents, structures, and roads under the high subsidence scenario compared to the 2023 floodplain. Our findings can support decision-makers and coastal communities along the Cascadia subduction zone as they prepare for compound hazards from the earthquake cycle and climate-driven sea-level rise and provide critical insights for tectonically active coastlines globally.more » « less
-
Abstract The thawing of permafrost in the Arctic has led to an increase in coastal land loss, flooding, and ground subsidence, seriously threatening civil infrastructure and coastal communities. However, a lack of tools for synthetic hazard assessment of the Arctic coast has hindered effective response measures. We developed a holistic framework, the Arctic Coastal Hazard Index (ACHI), to assess the vulnerability of Arctic coasts to permafrost thawing, coastal erosion, and coastal flooding. We quantified the coastal permafrost thaw potential (PTP) through regional assessment of thaw subsidence using ground settlement index. The calculations of the ground settlement index involve utilizing projections of permafrost conditions, including future regional mean annual ground temperature, active layer thickness, and talik thickness. The predicted thaw subsidence was validated through a comparison with observed long-term subsidence data. The ACHI incorporates the PTP into seven physical and ecological variables for coastal hazard assessment: shoreline type, habitat, relief, wind exposure, wave exposure, surge potential, and sea-level rise. The coastal hazard assessment was conducted for each 1 km2coastline of North Slope Borough, Alaska in the 2060s under the Representative Concentration Pathway 4.5 and 8.5 forcing scenarios. The areas that are prone to coastal hazards were identified by mapping the distribution pattern of the ACHI. The calculated coastal hazards potential was subjected to validation by comparing it with the observed and historical long-term coastal erosion mean rates. This framework for Arctic coastal assessment may assist policy and decision-making for adaptation, mitigation strategies, and civil infrastructure planning.more » « less
-
Jakarta, Indonesia’s capital, is increasingly characterized by luxury real estate developments and high-profile infrastructural projects made possible by economic liberalization and finance capital. Yet these developments have contributed to Jakarta’s struggles with chronic flooding, land subsidence, and water shortages. This paper contributes an empirical study of the spatial-temporal dynamics of speculative urbanism and the associated impacts on water resources and flood events in Jakarta. I use an urban political ecology approach to analyze mainland and offshore development. First, I show how financial speculation generates flood risk and the overexploitation of water resources, producing uneven socio-spatial distributions of risk. These transformations in Jakarta’s hydroscape in turn threaten to undermine the city’s viability as a site for speculative investment. I thus show how speculative urbanism can be threatened or disrupted by nonhuman agencies. Second, I illustrate a second form of speculation, which I refer to as environmental speculation. As Jakarta’s water crisis has cast doubt on the future of the city itself as a place of habitation, the state explored an ambitious and potentially lucrative coastal defense project, while private developers have engaged in land reclamation. The turn toward offshore development illustrates how environmental speculation creates new opportunities for capital accumulation. I advance two arguments: first, in order to capture the full costs of speculative urbanism, it is imperative that urban scholars attend to its ecological dimensions. Second, an urban political ecology approach advances our understandings of speculative urbanism by illuminating its contradictions and limits.more » « less
- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Conference Paper:
- https://doi.org/10.1109/IGARSS.2019.8897970
