Natural Hazards - The ice disaster risk in Ning-Meng reach of Yellow River in China is affected by many factors, and the various risk factors are not independent with each other but present... 相似文献
The salinization of freshwater-dependent coastal ecosystems precedes inundation by sea level rise. This type of saltwater intrusion places communities, ecosystems, and infrastructure at substantial risk. Risk perceptions of local residents are an indicator to gauge public support for climate change adaptation planning. Here, we document residential perspectives on the present and future threats posed by saltwater intrusion in a rural, low-lying region in coastal North Carolina, and we compare the spatial distribution of survey responses to physical landscape variables such as distance to coastline, artificial drainage density, elevation, saltwater intrusion vulnerability, and actual salinity measured during a synoptic field survey. We evaluate and discuss the degree of alignment or misalignment between risk perceptions and metrics of exposure to saltwater intrusion. Risk perceptions align well with the physical landscape characteristics, as residents with greater exposure to saltwater intrusion, including those living on low-lying land with high concentrations of artificial drainages, perceive greater risk than people living in low-exposure areas. Uncertainty about threats of saltwater intrusion is greatest among those living at higher elevations, whose properties and communities are less likely to be exposed to high salinity. As rising sea levels, drought, and coastal storms increase the likelihood of saltwater intrusion in coastal regions, integrated assessments of risk perceptions and physical exposure are critical for developing outreach activities and planning adaptation measures.
Acta Geochimica - In this paper, the Jurassic granitoid dike that intrudes into Permian diabase was reported in Luokun, Luodian County, south Guizhou. Zircon LA-ICP-MS U–Pb dating of the... 相似文献
Based on the principle of InSAR (Interferometirc Synthetic Aperture Radar) characterized by large-scale, continuity, permanency and dynamic, we took vertical displacement of solid Earth tide as an example to simulate the large-scale deformation observed by lunar based InSAR for the first time in the study and the observation ability was analyzed. Solid Earth tide has a feature of a large-space distribution range and the lunar based InSAR exhibits a feature of an ultra-wide swath imaging. According to these features, a simplified observation geometry model was established and a mid-low latitudes area with 50 degrees span in both longitude and latitude was selected as the simulation area. Then the revisit time intervals of the lunar based SAR for the selected area and the tidal vertical displacements at the points scanned by the radar were calculated. The time differentials were further computed to get the relative vertical deformation of the solid Earth tide. The simulation results show that the revisit period of the lunar based radar is about 24.8 hours and the maximum vertical displacement in 30 days is up to 30 cm. Since the designed accuracy of the lunar based InSAR reaches several centimeters, the observing of the vertical displacement of the solid Earth tide by using the lunar based InSAR is feasible in theory as the maximum magnitude of the vertical displacement is 1 order of magnitude larger than the designed accuracy. Theoretically ,solid Earth tide is observable by using lunar based InSAR in a sizable area.We can also use the observation data to study the temporal and spatial variation characteristics when observation time lasts two revisit periods or more. On the other hand,the result of the study also provides references for the parameter designing of other observations using the lunar based InSAR, especially for observing large-scale geodynamic phenomena. 相似文献