Inter-metropolitan migration of the newly landed immigrants in Canada: 1991–1996 and 1996–2001

Based on the tabulations of the Longitudinal Immigration Data Base, I characterized, explained and compared the 1991–1996 and 1996–2001 inter-metropolitan migration of the newly landed immigrants in Canada. The spatial and temporal patterns were consistent with the neoclassical economic theory and the ethnic enclave theory. In making their decisions on departure and destination choices, the immigrants were responsive to income and employment incentives, as well as the retaining and attracting powers of ethnic communities among Census Metropolitan Areas (CMAs). The research also discovered an interesting temporal pattern—while the inter-CMA migration of immigrants accentuated the over representation of the immigrants in Toronto and Vancouver in the 1991–1996 period, the rise of the “secondary” CMAs led to a spatial dispersal of the immigrants in the 1996–2001 period. This finding supplements the existing literature on internal migration of Canadian immigrants, which discovered little evidence of an increased dispersion of immigrants over time.     

Identifying urban–rural differences in social vulnerability to natural hazards: a case study of China

Identifying and analyzing the urban–rural differences of social vulnerability to natural hazards is imperative to ensure that urbanization develops in a way that lessens the impacts of disasters and generate building resilient livelihoods in China. Using data from the 2000 and 2010 population censuses, this study conducted an assessment of the social vulnerability index (SVI) by applying the projection pursuit cluster model. The temporal and spatial changes of social vulnerability in urban and rural areas were then examined during China’s rapid urbanization period. An index of urban–rural differences in social vulnerability (SVI_D) was derived, and the global and local Moran’s I of the SVI_D were calculated to assess the spatial variation and association between the urban and rural SVI. In order to fully determine the impacts of urbanization in relation to social vulnerability, a spatial autoregressive model and Bivariate Moran’s I between urbanization and SVI were both calculated. The urban and rural SVI both displayed a steadily decreasing trend from 2000 to 2010, although the urban SVI was always larger than the rural SVI in the same year. In 17.5% of the prefectures, the rural SVI was larger than the urban SVI in 2000, but was smaller than the urban SVI in 2010. About 12.6% of the urban areas in the prefectures became less vulnerable than rural areas over the study period, while in more than 51.73% of the prefectures the urban–rural SVI gap decreased over the same period. The SVI_D values in all prefectures had a significantly positive spatial autocorrelation and spatial clusters were apparent. Over time, social vulnerability to natural hazards at the prefecture-level displayed a gathering–scattering pattern across China. Though a regional variation of social vulnerability developed during China’s rapid urbanization, the overall trend was for a steady reduction in social vulnerability in both urban and rural areas.

     

Potential suitability for urban planning and industry development using natural hazard maps and geological–geomorphological parameters

During the planning of an urban environment, usually only economic and social parameters are taken into account. As a result, urban areas are susceptible to natural disasters, which cause extensive damages in them, because the cities or towns have been repeatedly located in vulnerable areas. In this study, for the protection of human environment, is proposed a unique approach of urban planning and sustainable development. The study area is Trikala Prefecture (Western Thessaly, Central Greece). An integrated evaluation of the suitable areas for urban growth and light industry development is proposed by using mainly natural hazards as well as geological–geomorphological–geographical characteristics of the study area. The used parameters were correlated by using the analytical hierarchical process (AHP) method and incorporated into a geographic information system (GIS) in order to produce the corresponding suitability maps. The study area is classified in five categories of very high, high, moderate, low, and very low suitability for urban growth and industrial development. Moreover, the spatio-temporal changes of the urban limits are studied since 1885 for the three major towns (Trikala, Kalambaka and Pyli) of the study area. These changes sketch out the urban growth trend. The comparison between the urban growth trend with the potential suitability for urban growth and industrial development of these towns lead to discrepancies. These can be attributed mainly to the fact that in the majority of cases, only geographical, social, and economical factors were used for urban development, whereas in our study, natural hazards, geomorphological, and geographical parameters were quantified and taken into account.     

Anthropogenic Pt and Pd concentrations in urban roadside soils from Xuzhou, China

The increased use of platinum group elements (PGE) as automobile catalysts has led to concern over potential environmental and biological accumulation. These inputs are greatest in urban areas, with the major sinks being roadside soils. This investigation…     

Natural disasters in China: 1900–2011

China is a country prone to high frequency of natural catastrophic events. According to the natural disaster data from 1900 to 2011, the major disaster types include drought, earthquake, epidemic, extreme temperature, flood, mass movement wet and storm. The occurrence of natural disaster and economic loss is increased during the studied period. However, the death toll induced by natural disaster is decreased significantly. A new frame of social development and natural disaster is proposed to discuss the impact of population and GDP on the influence of disaster through the recording and reduction efforts. The results indicated that economic development contributes to the reduction in the impact of natural disaster on the people lives and society. New comprehensive integrated management, including international cooperation, should be established.

     

Long-term groundwater storage changes and land subsidence development in the North China Plain (1971–2015)

The North China Plain (NCP) has been suffering from groundwater storage (GWS) depletion and land subsidence for a long period. This paper collects data on GWS changes and land subsidence from in situ groundwater-level measurements, literature, and satellite observations to provide an overview of the evolution of the aquifer system during 1971–2015 with a focus on the sub-regional variations. It is found that the GWS showed a prolonged declining rate of ?17.8?±?0.1 mm/yr during 1971–2015, with a negative correlation to groundwater abstraction before year ~2000 and a positive correlation after ~2000. Statistical correlations between subsidence rate and the GWS anomaly (GWSA), groundwater abstraction, and annual precipitation show that the land subsidence in three sub-regions (Beijing, Tianjin, and Hebei) represents different temporal variations due to varying driver factors. Continuous drought caused intensive GWS depletion (?76.1?±?6.5 mm/yr) and land subsidence in Beijing during 1999–2012. Negative correlations between total groundwater abstraction and land subsidence exhibited after the 1980s indicate that it may be questionable to infer subsidence from regional abstraction data. Instead, the GWSA generally provides a reliable correlation with subsidence. This study highlights the spatio-temporal variabilities of GWS depletion and land subsidence in the NCP under natural and anthropogenic impacts, and the importance of GWS changes for understanding land subsidence development.     

Contamination and distribution of heavy metals in urban soil in Zhangzhou City, Fujian, China

The urban environment quality is of vital importance as the majority of people now live in cities. Due to the continuous urbanization and industrialization with rapidly increasing economy in China, metals are continuously emitted into soils, imposing a great threat on human health. Urban soils might be affected by industrial activities, transport, agricultural practice, and waste disposal. An extensive survey was conducted in the highly urbanized Zhangzhou City （Fujian Province, China） using a systematic sampling strategy. Concentrations of Hg, Cd, Pb, Zn, Cu, As, Cr and Ni were measured on 108 topsoil samples collected from parks （0-15 cm）, residential areas and suburban agricultural soils. Statistic approach （cluster analysis） was adopted for identification of natural and anthropogenic influence on heavy metal contents. The maps of metal concentrations in surface soils were made based on geographical information system （GIS） data. All of these aim at assessing the distribution of these heavy metals in the urban environment.     

Tectonic evolution of Tarim basin in Cambrian–Ordovician and its implication for reservoir development,NW China

In order to find the impact of regional tectonic evolution of Tarim basin on the inside distribution of sedimentary facies and reservoir development, this paper, based on the research of plate-tectonic evolution of Tarim basin, conducts an in-depth analysis on the basin’s inside sedimentary response to the Eopaleozoic regional geodynamic reversion from extension to convergence around Tarim plate, and concludes that the regional geodynamic environment of surrounding areas closely contributes to the formation and evolution of paleo-uplifts, differentiation of sedimentary facies in platform, distribution of high-energy reef and bank facies belts, conversion of sedimentary base level from fall to rise, obvious change of lithology from dolomite to limestone, and formation of several unconformity surfaces in Ordovician system in the basin. A series of sedimentary responses in the basin are controlled by regional dynamic setting, which not only controls the distribution of reservoirs in reef and bank facies but also restricts the development and distribution of karst reservoirs controlled by the unconformity surfaces. This offers the macro geological evidences for us to further analyze and evaluate the distribution of favorable reservoirs.     

Women and strategic urban planning in Tehran: channeling women’s social capacity to prepare city development strategies

GeoJournal - City development strategy (CDS) is an urban strategic planning approach that has already been implemented in over 200 cities worldwide. Nevertheless, its preparation process is...     

Late Permian–early Middle Triassic back-arc basin development in West Qinling,China

The Late Permian–early Middle Triassic strata of the northern West Qinling area, northeastern Tibetan Plateau, are composed of sediment gravity flow deposits. Detailed sedimentary facies analysis indicates these strata were deposited in three successive deep-marine environments. The Late Permian–early Early Triassic strata of the Maomaolong Formation and the lowest part of the Longwuhe Formation define a NW–SE trending proximal slope environment. Facies of the Early Triassic strata composing the middle and upper Longwuhe Formation are consistent with deposition in a base-of-slope apron environment, whereas facies of the Middle Triassic Anisian age Gulangdi Formation are more closely associated with a base-of-slope fan depositional environment. The lithofacies and the spatial–temporal changes in paleocurrent data from these strata suggest the opening of a continental margin back-arc basin system during Late Permian to early Middle Triassic time in the northern West Qinling. U–Pb zircon ages for geochemically varied igneous rocks with diabasic through granitic compositions intruded into these deep-marine strata range from 250 to 234 Ma. These observations are consistent with extensional back-arc basin development and rifting between the Permian–Triassic Eastern Kunlun arc and North China block during the continent–continent collision and underthrusting of the South China block northward beneath the Qinling terrane of the North China block. Deep-marine sedimentation ended in the northern West Qinling by the Middle Triassic Ladinian age, but started in the southern West Qinling and Songpan-Ganzi to the south. We attribute these observations to southward directed rollback of Paleo-Tethys oceanic lithosphere, continued attenuation of the West Qinling on the upper plate, local post-rift isostatic compensation in the northern West Qinling area, and continued opening of a back-arc basin in the southern West Qinling and Songpan-Ganzi. Rollback and back-arc basin development during Late Permian to early Middle Triassic time in the West Qinling area explains: the truncated map pattern of the Eastern Kunlun arc, the age difference of deep-marine sediment gravity flow deposits between the Late Permian–early Middle Triassic northern West Qinling and the late Middle Triassic–Late Triassic southern West Qinling and Songpan-Ganzi, and the discontinuous trace of ophiolitic rocks associated with the Anyemaqen-Kunlun suture.     

Late Mesozoic magmatism and metallogeny in NE China: The Sandaowanzi–Beidagou example

The Sandaowanzi (>22t Au) and Beidagou (>5t Au) tellurium–gold deposits are located in the northeastern Central Asian Orogenic Belt (Heilongjiang Province, NE China). The ore-hosting volcanic rocks unconformably overly monzogranite and were intruded by adakitic granodiorite. In this study, we report new-age, geochemical, and Sr–Nd–Pb isotopic data to elucidate the genetic link between the igneous rocks and the Te–Au mineralization. New-age data indicate that local magmatism occurred in the Early Jurassic (ca. 177.2 Ma) and Early Cretaceous (ca. 118.7 ? 122.0 Ma). Geochemically, the igneous rocks are enriched in LREEs, Pb, K, and U, and depleted in Nb, P, and Ti, showing calc-alkaline affinity. The Early Jurassic monzogranite rocks are featured by ⁸⁷Sr/⁸⁶Sr = 0.7111?0.7118; ε_Nd(t) = ?4.6 to ?4.7; ²⁰⁶Pb/²⁰⁴Pb = 18.098?18.102, ²⁰⁷Pb/²⁰⁴Pb = 15.558?15.580, and ²⁰⁸Pb/²⁰⁴Pb = 37.781?37.928, whereas the Early Cretaceous adakitic granodiorite contains: ⁸⁷Sr/⁸⁶Sr = 0.7071?0.7073; ε_Nd(t) = ? 3.4 to ?3.2; ²⁰⁶Pb/²⁰⁴Pb = 17.991?18.080, ²⁰⁷Pb/²⁰⁴Pb = 15.483?15.508, and ²⁰⁸Pb/²⁰⁴Pb = 37.938?37.985. Initial isotopic ratios for the Early Cretaceous volcanic rocks: ⁸⁷Sr/⁸⁶Sr = 0.7061?0.7087; ε_Nd(t) = ? 3.6 to ?2.9; ²⁰⁶Pb/²⁰⁴Pb = 18.136?18.199, ²⁰⁷Pb/²⁰⁴Pb = 15.512?15.628, and ²⁰⁸Pb/²⁰⁴Pb = 38.064?38.155. The pyrite, chalcopyrite, and telluride grains yielded δ³⁴S of ?6.52 ‰ to 2.13 ‰ (mean = ? 0.82 ‰) and δ¹³C_PDB of the calcite samples are in the range of ?6.64 ‰ to ?5.24 ‰, implying the ore materials were derived from mantle. The geochemical and isotopic results indicate that primary melts of Late Mesozoic magmatic rocks have features by partial melting of the continental crust. The adakitic rocks may have been the products of the thickened lower crustal delamination and the subsequent asthenospheric upwelling during the intra-continental extension in NE China. Regionally, intrusive activity and molybdenum mineralization during the Jurassic was affected by subduction setting, whereas gold mineralization was controlled by the Early Cretaceous tectonothermal events associated with a superposition extension.     

Pareto’s law and sample size: a case study of China’s urban system 1984–2008

While Pareto’s law has been widely supported by empirical evidence in urban studies, past studies have focused on finding best fits for city rank-size distribution. A main concern with Pareto’s law is the truncation of sample selection, for which few studies have examined it directly. This study tests three existing threshold methods (number threshold, size threshold, and urban population percentage threshold) using China’s city system as a case study. In addition, this study proposes a new method based upon the percentage threshold of the total number of cities. A systematic analysis is applied to examine the relationship between Pareto exponent and sample size using different threshold methods. The results show that Pareto exponent is sensitive to sample size and the truncation point. Including only large cities is problematic because a slight change in the truncation point will yield quite different results of Pareto exponent. In addition, the new method, the percentage threshold of the total number of cities method, presents an advantage over previous methods, in that this method yields a consistent set of results over a wide range of thresholds. Finally, when using this new method with China’s city system, the Pareto exponent presents a turning point in 1996, representing China’s transition from a planned economy to a more market oriented economy during that period.     

Spatial–temporal changes in meteorological and agricultural droughts in Northeast China: change patterns,response relationships and causes

Natural Hazards - Under the background of climate warming, drought events occur frequently. Generally, meteorological drought leads to agricultural drought. Understanding the spatiotemporal...     

Patterns of population change in Ghana (1984–2000): urbanization and frontier development

The study addresses population dynamics in Ghana on the urban and regional levels between 1984 and 2000. At the urban level, the development trends are analyzed for urban localities (population above 5,000) on the basis of geo-coded census data. Potential driving forces for rapid population growth related to size, location, accessibility and facility counts are examined using bivariate and multivariate analysis. An index of weighted accessibility relative to other urban localities provides significant explanation at the national level, as does initial locality size. At the regional level, population development is analyzed to provide insight into the rural–urban relations. The level of urbanization is steadily increasing but varies considerably between regions. Areas of high population growth are found in some rural areas that have a remote location relative to the large urban centers. This seems to indicate the existence of ‘frontier’ regions, i.e. areas that experience a high degree of in-migration by people aiming to undertake specific farming activities. A high proportion of the population growth in these areas appears to take place in relatively small towns. The paper concludes with a more in-depth discussion of the development characteristics of Ghana’s Western Region. This region has experienced one of the highest regional population growth rates, mainly due to its status as a ‘frontier’ for cocoa production.

Tokur gold ore–placer cluster in Amur Province: Geological–structural features and perspective of its development

The geological–structural features and gold-potential perspective of the Tokur ore–placer cluster in the Amur Province have been studied. This ore–placer cluster is a syncline composed of Paleozoic blackshale sequence, which is cut through by Late Paleozoic and Late Mesozoic intrusions. A granitoid massif is suggested at the depth on the basis of geophysical data. The cluster is distinguished by high productivity. Approximately 37 t gold from ore deposits, primarily from the Tokur deposit, and 60 t from placers have been mined out. The Tokur deposit is compared with the Natalka and Degdekan deposits from the Yana–Kolyma Province. Perspectives of the cluster area for large gold–quartz deposits and technogenic gold placers have been estimated.     

Hazardous area map: an approach of sustainable urban planning and industrial development—a review

Natural Hazards - A hazard map is a map which shows about all the vulnerable regions present in any country or at any specific place or location which is affected or will be affected by natural...     

Estimation of agricultural greenhouse gases emission in interprovincial regions of China during 1996–2014

Natural Hazards - Agriculture is an important component of national economy in China, and agricultural production is also an important source of greenhouse gas emission. Based on the methods of...