Vancouver’s newest Chinese diaspora: settlers or “immigrant prisoners”?     

Sin Yih Teo 《GeoJournal》2007,68(2-3):211-222

This study seeks to reground concepts of “diaspora” and “transnationalism” in the realities of everyday life through examining the lived experiences of immigrants. Based on in-depth household interviews and focus groups, it examines the newest Chinese diaspora in Vancouver—skilled immigrants from the People’s Republic of China. It explores the challenges that they face in an unfamiliar city, including employment and language barriers as well as domestic anxieties surrounding childcare, education and marital difficulties. The strategies that they adopt to counter these problems are at times transnational—in the form of astronaut families or transnational childcare—but almost always familial. Ultimately, the settlement challenges that they face, coupled with the available transnational possibilities, raise the question of whether they are settlers or “immigrant prisoners”, temporarily serving their time in Vancouver before a further relocation.  相似文献   

High Resolution Passive Imaging Using Dense Geophone Arrays     

FanChi Lin  Yadong Wang  Sin Mei Wu  Elizabeth Berg  Kevin War  Amir Allam  Jamie Farrell 《《地质学报》英文版》2018,92(Z1):280-280

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Interaction of ENSO-driven Flood Variability and Anthropogenic Changes in Driving Channel Evolution: Corryong/Nariel Creek,Australia     

Elisha A. Teo  Philip M. Marren 《The Australian geographer》2015,46(3):339-362

Understanding the relative contributions of climatic and anthropogenic drivers of channel change are important to inform river management, especially in the context of environmental change. This global debate is especially pertinent in Australia as catchments have been severely altered since recent European settlement, and there is also strong evidence of cyclical climate variability controlling environmental systems. Corryong/Nariel Creek is an ideal setting to further study the interaction between climate and anthropogenic changes on channel evolution as it has experienced both significant periods of flood and drought, controlled by the El Niño Southern Oscillation (ENSO), and extensive anthropogenic changes. Since European settlement the floodplain has been completely cleared, the riparian zone almost entirely invaded by willows, and every reach of the channel has experienced some form of direct channel modification. Through the combined analysis of channel evolution, climate changes and anthropogenic history of the river it was found that both the ENSO-driven climate and anthropogenic drivers are significant, although at different scales of channel change. Significant straightening in response to land clearing in the early twentieth century occurred before any records of direct channel modifications. Following this, most river management works were in response to instabilities created in the clearing period, or to instabilities created by flooding triggering a new phase of instability in reaches which had already undergone stabilisation works. Overall, human activities triggered channel instability via land clearing, and management works since then generally exacerbated erosion during high flows that are driven by climate fluctuations. This research raises the interesting question of whether rivers in Australia have become more responsive to the ENSO cycle since the clearing of catchment and riparian vegetation, or whether the past response to climate variability was different.  相似文献   

Predicting sediment discharges and erosion rates in deep time—examples from the late Cretaceous North American continent     

Sinéad J. Lyster  Alexander C. Whittaker  Peter A. Allison  Daniel J. Lunt  Alexander Farnsworth 《Basin Research》2020,32(6):1547-1573

Depositional stratigraphy represents the only physical archive of palaeo-sediment routing and this limits analysis of ancient source-to-sink systems in both space and time. Here, we use palaeo-digital elevation models (palaeoDEMs; based on high-resolution palaeogeographic reconstructions), HadCM3L general circulation model climate data and the BQART suspended sediment discharge model to demonstrate a predictive, forward approach to palaeo-sediment routing system analysis. To exemplify our approach, we use palaeoDEMs and HadCM3L data to predict the configurations, geometries and climates of large continental catchments in the Cenomanian and Turonian North American continent. Then, we use BQART to estimate suspended sediment discharges and catchment-averaged erosion rates and we map their spatial distributions. We validate our estimates with published geologic constraints from the Cenomanian Dunvegan Formation, Alberta, Canada, and the Turonian Ferron Sandstone, Utah, USA, and find that estimates are consistent or within a factor of two to three. We then evaluate the univariate and multivariate sensitivity of our estimates to a range of uncertainty margins on palaeogeographic and palaeoclimatic boundary conditions; large uncertainty margins (≤50%/±5°C) still recover estimates of suspended sediment discharge within an order of magnitude of published constraints. PalaeoDEMs are therefore suitable as a first-order investigative tool in palaeo-sediment routing system analysis and are particularly useful where stratigraphic records are incomplete. We highlight the potential of this approach to predict the global spatio-temporal response of suspended sediment discharges and catchment-averaged erosion rates to long-period tectonic and climatic forcing in the geologic past.  相似文献   

Spatial and temporal characteristics of nutrient and phytoplankton dynamics in the York River Estuary, Virginia: Analyses of long-term data   总被引：1，自引：0，他引：1  

Yongsik Sin  Richard L. Wetzel  Iris C. Anderson 《Estuaries and Coasts》1999,22(2):260-275

Ten years (1985–1994) of data were analyzed to investigate general patterns of phytoplankton and nutrient dynamics, and to identify major factors controlling those dynamics in the York River Estuary, Virginia. Algal blooms were observed during winter-spring followed by smaller summer blooms. Peak phytoplankton biomass during the winter-spring blooms occurred in the mid reach of the mesohaline zone whereas peak phytoplankton biomass during the summer bloom occurred in the tidal fresh-mesohaline transition zone. River discharge appears to be the major factor controlling the location and timing of the winter-spring blooms and the relative degree of potential N and P limitation. Phytoplankton biomass in tidal fresh water regions was limited by high flushing rates. Water residence time was less than cell doubling time during high flow seasons. Positive correlations between PAR at 1 m depth and chlorophylla suggested light limitation of phytoplankton in the tidal fresh-mesohaline transition zone. Relationships of salinity difference between surface and bottom water with chlorophylla distribution suggested the importance of tidal mixing for phytoplankton dynamics in the mesohaline zone. Accumulation of phytoplankton biomass in the mesohaline zone was generally controlled by N with the nutrient supply provided by benthic or bottom water remineralization.  相似文献   

Complex use of satellite radiometric,surface radar,and cloud numerical modeling data for controlling the modification works aiming to prevent precipitation in Peterhof     

A. A. Sin’kevich  N. E. Veremey  N. N. Volkov  Yu. A. Dovgalyuk  V. D. Stepanenko  G. G. Shchukin 《Russian Meteorology and Hydrology》2010,35(10):665-672

Results are presented of complex study of the clouds during the modification works aiming to prevent precipitation. To estimate the modification effect, a new technique is presented based upon comparison of the IR-radiometer measurements data, from the Meteosat satellite, on radiation temperature of the clouds after modification and those in natural development cycle. It is shown that for the case under study, radiation temperature increase is observed in the pixel corresponding to the city in which precipitation should be prevented.  相似文献   

Seasonal climate hindcasts with Eta model nested in CPTEC coupled ocean–atmosphere general circulation model     

Isabel L. Pilotto  Sin Chan Chou  Paulo Nobre 《Theoretical and Applied Climatology》2012,110(3):437-456

This work evaluates the added value of the downscaling technique employed with the Eta model nested in the CPTEC atmospheric general circulation model and in the CPTEC coupled ocean?Catmosphere general circulation model (CGCM). The focus is on the austral summer season, December?CJanuary?CFebruary, with three members each year. Precipitation, latent heat flux, and shortwave radiation flux at the surface hindcast by the models are compared with observational data and model analyses. The global models generally overestimate the precipitation over South America and tropical Atlantic. The CGCM and the nested Eta (Eta + C) both produce a split in the ITCZ precipitation band. The Eta + C produces better precipitation pattern for the studied season. The Eta model reduces the excessive latent heat flux generated by these global models, in particular the Eta + C. Comparison against PIRATA buoys data shows that the Eta + C results in the smallest precipitation and shortwave radiation forecast errors. The Eta + C comparatively best results are though as a consequence of both: the regional model resolution/physics and smaller errors on the lateral boundary conditions provided by the CGCM.  相似文献   

Radar investigations of cloud merger     

T. W. Krauss  A. A. Sin’kevich  A. S. Ghulam 《Russian Meteorology and Hydrology》2012,37(9):604-614

Presented are the results of radar investigations of cloud merger during their natural cycle of development and after the seeding. The observations were carried out in the southwest of the Kingdom of Saudi Arabia in 2008. It is revealed that the merging was observed under conditions of very unstable atmosphere, when the convective available potential energy exceeded 3000 J/kg. The cloud merger impacts significantly their development. The most considerable changes due to the cloud merging were observed for the cloud mass and precipitation flow increased as a result of this process by two or three times. It is discovered that the impact of the merger of clouds on their characteristics exceeds significantly the effect of seeding carried out for the feeder clouds.  相似文献   

Investigation of the impact of dynamic factors on Cb cloud development in Saudi Arabia     

T. W. Krauss  A. A. Sin’kevich  R. Burger  N. E. Veremei  Yu. A. Dovgalyuk  V. D. Stepanenko 《Russian Meteorology and Hydrology》2011,36(10):643-652

Changes are analyzed of a Cb cloud characteristics due to its merging with feeder clouds, on the data on a long-living Cb cloud in Saudi Arabia on July 4, 2008. Continuous radar and satellite observations of the cloud are carried out during 6 h. The Cb cloud development is also numerically simulated using a nonstationary 1½ model. It is found that the processes of Cb cloud merging with feeder clouds developing in its vicinities affect significantly the Cb cloud development. This impact demonstrates itself in longer duration of the Cb cloud life span, increasing top height, reflectivity, precipitation duration and intensity. Modification of the feeder clouds can accelerate their development, which eventually can affect notably the Cb cloud.  相似文献   

Experimental study of consolidation properties of unsaturated soils during draining     

Kai‐Yuan Ke  Yih‐Chi Tan  Chu‐Hui Chen  Kin‐Sang Chim  Tian‐Chyi J. Yeh 《水文研究》2004,18(13):2565-2578

Changes in groundwater elevation may cause a change in the net normal stress and matric potential within the soil mass, which results in volume changes of unsaturated soil. This research investigated the relationship between the drawdown of groundwater and the characteristics of volumetric compressibility of unsaturated soil. Sand column experiments were designed and conducted to measure the volume changes of coarse and fine sands under different types of drainage conditions at fast and slow drainage rates. The finite element program FEMWATER was calibrated and used to simulate the distributions of stress, tension and moisture content within the sands. Finally, based on the changes of net normal stress and matric potential and the observed volume change of the sands, a least‐square method was applied to determine the volumetric consolidation parameters of the unsaturated soils. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献