The immigration patterns of the last three decades have profoundly changed nearly every aspect of life in the United States. What do those changes mean for the most established Americans-those whose ...families have been in the country for multiple generations?The Other Side of Assimilationshows that assimilation is not a one-way street. Jiménez explains how established Americans undergo their own assimilation in response to profound immigration-driven ethnic, racial, political, economic, and cultural shifts. Drawing on interviews with a race and class spectrum of established Americans in three different Silicon Valley cities,The Other Side of Assimilationilluminates how established Americans make sense of their experiences in immigrant-rich environments, in work, school, public interactions, romantic life, and leisure activities. With lucid prose, Jiménez reveals how immigration not only changes the American cityscape but also reshapes the United States by altering the outlooks and identities of its most established citizens.
Replenished ethnicity Jimenez, Tomas R; Jimenez, Tomas R
2010., 20091019, 2009, c2010., 2009-11-18, 20100101
eBook
Unlike the wave of immigration that came through Ellis Island and then subsided, immigration to the United States from Mexico has been virtually uninterrupted for one hundred years. In this vividly ...detailed book, Tomás R. Jiménez takes us into the lives of later-generation descendents of Mexican immigrants, asking for the first time how this constant influx of immigrants from their ethnic homeland has shaped their assimilation. His nuanced investigation of this complex and little-studied phenomenon finds that continuous immigration has resulted in a vibrant ethnicity that later-generation Mexican Americans describe as both costly and beneficial. Replenished Ethnicity sheds new light on America's largest ethnic group, making it must reading for anyone interested in how immigration is changing the United States.
Beijing is one of the most water-stressed cities in the world. Due to over-exploitation of groundwater, the Beijing region has been suffering from land subsidence since 1935. In this study, the Small ...Baseline InSAR technique has been employed to process Envisat ASAR images acquired between 2003 and 2010 and TerraSAR-X stripmap images collected from 2010 to 2011 to investigate land subsidence in the Beijing region. The maximum subsidence is seen in the eastern part of Beijing with a rate greater than 100 mm/year. Comparisons between InSAR and GPS derived subsidence rates show an RMS difference of 2.94 mm/year with a mean of 2.41 plus or minus 1.84 mm/year. In addition, a high correlation was observed between InSAR subsidence rate maps derived from two different datasets (i.e., Envisat and TerraSAR-X). These demonstrate once again that InSAR is a powerful tool for monitoring land subsidence. InSAR derived subsidence rate maps have allowed for a comprehensive spatio-temporal analysis to identify the main triggering factors of land subsidence. Some interesting relationships in terms of land subsidence were found with groundwater level, active faults, accumulated soft soil thickness and different aquifer types. Furthermore, a relationship with the distances to pumping wells was also recognized in this work.
The launch of the medium resolution Synthetic Aperture Radar (SAR) Sentinel-1 constellation in 2014 has allowed public and private organizations to introduce SAR interferometry (InSAR) products as a ...valuable option in their monitoring systems. The massive stacks of displacement data resulting from the processing of large C-B and radar images can be used to highlight temporal and spatial deformation anomalies, and their detailed analysis and postprocessing to generate operative products for final users. In this work, the wide-area mapping capability of Sentinel-1 was used in synergy with the COSMO-SkyMed high resolution SAR data to characterize ground subsidence affecting the urban fabric of the city of Pistoia (Tuscany Region, central Italy). Line of sight velocities were decomposed on vertical and E-W components, observing slight horizontal movements towards the center of the subsidence area. Vertical displacements and damage field surveys allowed for the calculation of the probability of damage depending on the displacement velocity by means of fragility curves. Finally, these data were translated to damage probability and potential loss maps. These products are useful for urban planning and geohazard management, focusing on the identification of the most hazardous areas on which to concentrate efforts and resources.
In recent years, there was an increasing number of studies focusing on rockfalls due to their impacts on social and sustainable development. This work carries out a three-dimensional (3D) simulation ...of rockfalls at a cultural heritage site nearby the village of Cortes de Pallás (Valencian Community, East Spain). The simulation is based on data collected previously, during an emergency declaration due to the occurrence of a considerable rockfall (7980 m3) on the southern bank of the Cortes de Pallás reservoir, on 6 April 2015. The hydroelectric power plant was damaged, and the main access road to the village of Cortes de Pallás was blocked for eight months. The predominant discontinuities of the rock mass were analyzed by means of the application of structure from motion (SfM) photogrammetry techniques to the set of images taken by remotely piloted aircraft systems (RPAS). The average size of the block was determined as 3.2 m in diameter and 17.6 m3 in volume. Additionally, a digital elevation model (DEM) was generated from an aerial laser scanning (ALS)-derived point cloud using a 1 × 1 grid. These data were implemented in RocPro3D software, obtaining the distances traveled by the blocks detached from different source areas at a cultural heritage site located near the rockfall event, which presents the same geological context. The simulation presented herein shows aggravating circumstances that endanger the cultural heritage area, with higher rockfall hazards than previous official studies (1991) displayed.
The extraction of underground minerals in hilly regions is highly susceptible to landslides, which requires the application of InSAR techniques to monitor the surface displacement. However, repeated ...mining for multiple coal seams can cause a large displacement beyond the detectable gradient of the traditional InSAR technique, making it difficult to explore the relationship between landslides and subsurface excavations in both temporal and spatial domains. In this study, the Tengqing landslide in Shuicheng, Guizhou, China, was chosen as the study area. Firstly, the large-gradient surface displacement in the line of sight was obtained by the fusion of SAR offset tracking and interferometric phase. Subsequently, a multi-segment logistic model was proposed to simulate the temporal effect induced by repeated mining activities. Next, a simplified probability integral method (SPIM) was utilized to invert the geometry of the mining tunnel and separate the displacement of the mining subsidence and landslide. Finally, the subsurface mining parameters and in situ investigation were carried out to assess the impact of mining and precipitation on the kinematic process of Tengqing landslides. Results showed that the repeated mining activities in Tengqing can not only cause land subsidence and rock avalanches at the top of the mountain, but also accelerate the landslide displacement. The technical approach presented in this study can provide new insights for monitoring and modeling the effects of repeated mining-induced landslides in mountainous areas.
Finding new ways to quantify discontinuity persistence values in rock masses in an automatic or semi-automatic manner is a considerable challenge, as an alternative to the use of traditional methods ...based on measuring patches or traces with tapes. Remote sensing techniques potentially provide new ways of analysing visible data from the rock mass. This work presents a methodology for the automatic mapping of discontinuity persistence on rock masses, using 3D point clouds. The method proposed herein starts by clustering points that belong to patches of a given discontinuity. Coplanar clusters are then merged into a single group of points. Persistence is measured in the directions of the dip and strike for each coplanar set of points, resulting in the extraction of the length of the maximum chord and the area of the convex hull. The proposed approach is implemented in a graphic interface with open source software. Three case studies are utilized to illustrate the methodology: (1) small-scale laboratory setup consisting of a regular distribution of cubes with similar dimensions, (2) more complex geometry consisting of a real rock mass surface in an excavated cavern and (3) slope with persistent sub-vertical discontinuities. Results presented good agreement with field measurements, validating the methodology. Complexities and difficulties related to the method (e.g., natural discontinuity waviness) are reported and discussed. An assessment on the applicability of the method to the 3D point cloud is also presented. Utilization of remote sensing data for a more objective characterization of the persistence of planar discontinuities affecting rock masses is highlighted herein.
•Mining subsidence dynamics was remotely monitored.•Quality and accuracy improved with the duration of the in-orbit performance test.•The control of surface deformation dynamics was ...analyzed.•Potential damage to infrastructures was evaluated.
Monitoring of mining-induced subsidence dynamics enables to the exploration and analysis of changes in the direction of surface deformation caused by the extraction of underground resources. Both human activities and geological environments affect these changes to a large extent. LuTan-1 (LT-1) satellite as the first SAR mission with L-band bistatic spaceborne in China, provides continuous imagery for analyzing surface deformations through differential SAR interferometry, offering valuable velocity results using stacking techniques. The results of the subsidence bowl obtained from LT-1 closely align with those from Sentinel-1 in the almost same period in Datong, China. Furthermore, we validated the DInSAR results of LT-1 and Sentinel-1 using continuous GNSS data from the corresponding time frames. Notably, we observed a significant improvement in the quality and accuracy of LT-1 datasets due to the in-orbit performance test. Finally, we explored the surface deformation dynamics pertinent to mining activities using DInSAR results obtained from four different time periods. These results revealed substantial changes on the shape and spatial location of the subsidence bowls over time. This indicates a maximum horizontal displacement in the directional change of approximate 1.429 km and an average face advance rate between 0.724 and 6.355 m/day within about a one-year time period. Lastly, velocity and accumulated displacement gradient maps, derived from stacking results, were overlaid to the distribution of critical infrastructures in the study areas to assess their exposure to mining subsidence, and a validation process was carried out using GF-7 optical images. This study emphasizes the potential of LT-1 to monitor mining subsidence dynamics and its capability for joint analysis with the exposure of critical infrastructures.
Landslides are considered to be one of the main natural geohazards causing relevant economic damages and social effects worldwide. Italy is one of the countries worldwide most affected by landslides; ...in the Region of Tuscany alone, more than 100,000 phenomena are known and mapped. The possibility to recognize, investigate, and monitor these phenomena play a key role to avoid further occurrences and consequences. The number of applications of Advanced Differential Interferometric Synthetic Aperture Radar (A-DInSAR) analysis for landslides monitoring and mapping greatly increased in the last decades thanks to the technological advances and the development of advanced processing algorithms. In this work, landslide-induced damage on structures recognized and classified by field survey and velocity of displacement re-projected along the steepest slope were combined in order to extract fragility curves for the hamlets of Patigno and Coloretta, in the Zeri municipality (Tuscany, northern Italy). Images using ERS1/2, ENVISAT, COSMO-SkyMed (CSK) and Sentinel-1 SAR (Synthetic Aperture Radar) were employed to investigate an approximate 25 years of deformation affecting both hamlets. Three field surveys were conducted for recognizing, identifying, and classifying the landslide-induced damage on structures and infrastructures. At the end, the damage probability maps were designed by means of the use of the fragility curves between Sentinel-1 velocities and recorded levels of damage. The results were conceived to be useful for the local authorities and civil protection authorities to improve the land managing and, more generally, for planning mitigation strategies.
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