China: population change and population control

Since 1949 China's population has increased by 500 million and thereby grown at an average rate of 2 % per year. Annual growth rates have varied dramatically, falling from 3.3 % in 1963 to 1.2 % in 1979 and registering a population decline of 13.5 million in the famine years of 1960/61. China's demographic disaster in 1958/61 ranks as one of the most devastating in the history of the world. Chinese leaders have oscillated between pro- and anti-natalist policies. However, in the 1970s the government launched its third, its most intensive and to date its most successful family planning programme. So succesful that the total fertility rate declined from 6.4 in 1968 to 2.2 in 1980 and the level of contraceptive use in China was raised to the levels currently experienced in the Developed World. Despite the high rate of contraceptive prevalence, induced abortion is still extensively used to prevent unplanned births. The extent to which China's birth control programme has been implemented on a voluntary, coercive or compulsory basis is open to question. A rapid increase in the age of marriage and a substantial improvement in female education have made important contributions to the decline in fertility. Large differences in fertility exist between rural and urban China, reflecting significant differences in the average age of marriage and the very marked difference in educational attainment between the cities and the countryside. Whether the government directed family planning programme or socio-economic development has had the greatest impact on the decline in fertility, is under discussion. Whatever the motive force, the pace of demographic modernisation has been impressive and by international standards China now enjoys advanced levels of demographic development at an early stage of economic development.Abbreviations CMP-SPRCP-75-114 China Mainland Press, Survey of People's Republic of China Press 1975, No. 114. - FBIS-CHI-83-112 Foreign Broadcast Information Service, Daily Report, China, 1983, No. 112. - JPRS-CPS-85-012 Joint Publications Research Service, China Report, Political, Sociological and Military Affairs, 1985, No. 12. - SWB/FE/6246/BII Summary of World Broadcast, Far East, No. 6246, section BII.     

Quantifying the effects of environmental change on an oyster population: A modeling study

Three models are combined to investigate the effects of changes in environmental conditions on the population structure of the Eastern oyster,Crassostrea virginica. The first model, a time-dependent model of the oyster population as described in Powell et al. (1992, 1994, 1995a,b, 1996, 1997) and Hofmann et al. (1992, 1994, 1995), tracks the distribution, development, spawning, and mortality of sessile oyster populations. The second model, a time-dependent larval growth model as described in Dekshenieks et al. (1993), simulates larval growth and mortality. The final model, a finite element hydrodynamic model, simulates the circulation in Galveston Bay, Texas. The coupled post-settlement-larval model (the oyster model) runs within the finite element grid at locations that include known oyster reef habitats. The oyster model was first forced with 5 yr of mean environmental conditions to provide a reference simulation for Galveston Bay. Additional simulations considered the effects of long-term increases and decreases in freshwater inflow and temperature, as well as decreases in food concentration and total seston on Galveston Bay oyster populations. In general, the simulations show that salinity is the primary environmental factor controling the spatial extent of oyster distribution within the estuary. Results also indicate a need to consider all environmental factors when attempting to predict the response of oyster populations; it is the superposition of a combination of these factors that determines the state of the population. The results from this study allow predictions to be made concerning the effects of environmental change on the status of oyster populations, both within Galveston Bay and within other estuarine systems supporting oyster populations.     

Climate change and the future of freshwater resources of the island: a case study on the Rishiri Island,Japan

A comparison of the d-excess values of precipitation and of spring water, streams, groundwater wells and submarine groundwater discharge indicated that the precipitation that occurred during winter season was an important source of groundwater recharge. Due to the steep slope of the island, most of the short duration and high intensity precipitation is lost through direct surface runoff. The comparison indicated that snowmelt is an important resource of groundwater recharge on Rishiri Island. Future climate change will continue to diminish the snowpack, and therefore, reduce groundwater recharge. It may cause the decline of the groundwater level in the coastal area and possibly shift the saline–freshwater boundary on the island. Chloride data indicated that saltwater intrusion is beginning to occur on the western flank of the island. A Piper diagram shows that the water samples are characterized by the dominance of the Ca–HCO₃ and Na–Cl type. Their chemistry probably results from sea salt spray and the dissolution of minerals. These results support the need for the effective management of groundwater resources.     

The Holocene volcanic history of Gran Canaria island: implications for volcanic hazards

Previous published data, combined with our results of 13 new radiocarbon ages and extensive geological fieldwork, indicate that during the past 11 ka 24 monogenetic basaltic eruptions occurred in the north sector of Gran Canaria. These eruptions can be grouped into three periods of eruptive activity: 1900–3200 ¹⁴C a BP; 5700–6000 ¹⁴C a BP; and an older period represented by only one eruption, El Draguillo, dated at 10 610 ± 190 ¹⁴C a BP. Archaeological studies have shown that the more recent eruptions affected prehistoric human settlements on the island. Field studies demonstrate that the eruptions typically built strombolian cones (30–250 m in height) and associated relatively long lava flows (100–10 350 m in length); a few eruptions also produced tephra fall deposits. The total erupted volume of these eruptions is about 0.388 km³ (46.1% as tephra fall, 41.8% as cinder cone deposits and 12.1% as lava flows). The relatively low eruption rate (～0.04 km³ ka^?1) during the past 11 ka is consistent with Gran Canaria's stage of evolution in the regional volcano‐tectonic setting of the Canary Archipelago. The results of our study were used to construct a volcanic hazards map that clearly delimits two sectors in the NE sector of Gran Canaria, where potential future eruptions would pose a substantial risk for densely populated areas. Copyright © 2009 John Wiley & Sons, Ltd.     

The tourism disaster vulnerability framework: an application to tourism in small island destinations

Islands are known to be vulnerable to natural hazards, resulting in substantial risks for their tourism industries. To facilitate the systematic analysis of the underlying vulnerability drivers, a tourism disaster vulnerability framework was developed. The conceptual model then guided qualitative empirical research in three regions: the Caribbean, the South Pacific, and the Indian Ocean. The results from 73 interviews highlight common, as well as idiosyncratic, factors that shape the islands’ hazardscapes and vulnerabilities. Key vulnerabilities included social, economic, political, and environmental dimensions. Probably, the most critical vulnerability driver is the lack of private sector investment in disaster risk reduction. This is interrelated with deficient planning processes, on-going demand for coastal products, lack of political will, and poor environmental conditions. Notwithstanding many barriers, some businesses and organisations engage proactively in addressing disaster risk. The paper’s empirical evidence supports the validity of the framework, and suggestions for further research are made.     

利用地球化学方法判别大陆玄武岩和岛弧玄武岩

大陆地壳或岩石圈的混染作用可以给出似消减带信号,并导致将受到混染的大陆玄武岩误判为岛弧玄武岩。没有受到混染的软流圈(或地幔柱)源大陆玄武质岩石通常是以(Th/Nb)N<1、Nb/La≥1、低87Sr/86Sr(t)比值、高εNd(t)值及La/Nb和La/Ba比值与洋岛玄武岩相似并以具有缺乏Nb、Ta、Ti负异常的“隆起”状多元素地幔标准化分配型式为特征。当在所研究的火山岩系中发现有未受到混染的软流圈(或地幔柱)源玄武质岩石存在,基本上就可以排除它们有属于岛弧或活动大陆边缘火山岩系的可能。对于那些具有消减带信号的基性熔岩,可以根据Zr含量和Zr/Y比值,或利用Zr/Y-Zr图解,判断它们是否真正是岛弧或活动大陆边缘玄武岩。     

The maximum ice extent on island groups in the Scotia sea,Antarctica

Evidence is presented for a more extensive ice cover over South Georgia, the South Orkney Islands, the South Shetland Islands, and the tip of the Antarctic Peninsula. Ice extended across the adjacent submarine shelves to a depth of 200 m below present sea level. Troughs cut into the submarine shelves by ice streams or outlet glaciers and ice-scoured features on the shelf areas suggest that the ice caps were warm-based. The South Shetland Islands appear not to have been overrun by continental ice. Geomorphological evidence in two island groups suggests that the maximum ice cover, which was responsible for the bulk of glacial erosion, predates at least one full glaciation. Subsequently there was a marine interval and then a glaciation which overran all of the lowlying peninsulas. The Falkland Islands, only 2° of latitude north of South Georgia, were never covered by an ice cap and supported only a few slightly enlarged cirque glaciers. This suggests that the major oceanographic and atmospheric boundary represented by the Antarctic Convergence, which is presently situated between the Falkland Islands and South Georgia, has remained in a similar position throughout the glacial age. Its position is probably bathymetrically controlled.     

The human ecology of global change: Unresolved questions

The need to view human activity as an integral component of the geosphere-biosphere system has been emphasized since the earliest writings on global environmental change. In recent years, however, the long-term, large-scale interactions between human activities and the world's environment have become the focus of increasing practical and scholarly attention. Several national and international programs are beginning to plan systematic research strategies for better understanding those interactions. This paper attempts to review and summarize the major conclusions of these early planning efforts through a discussion of the major unresolved questions relating to the human ecology of global change.     

The Pleistocene palaeoenvironment and stratigraphy of Flatey island (northern Iceland): a preliminary assessment based on palynomorphs

For the first time, palynological data (pollen, spores and dinoflagellate cysts) from Pleistocene outcrop and core deposits from Flatey, off northern Iceland, are presented. The study provides a reconnaissance stratigraphical assessment of the deposits, the correlation between the Pleistocene of Flatey and the well‐known Tjörnes section on the mainland, and the reconstruction of the Pleistocene palaeoenvironment. The preservation of the assemblages is poor to moderate, whereas the diversity and richness are moderate to high. The pollen and spores indicate vegetation composed mainly of sedges and heath, comparable to the vegetation in the Tjörnes area during deposition of the Pleistocene Breidavík Group. Analysis of dinoflagellate cyst assemblages from an outcrop sample allowed their assignment to the Lower Pleistocene dinoflagellate cyst zone DAZ5, previously defined in the Tjörnes section. A core sample yielded a dinoflagellate cyst assemblage unknown from the Tjörnes area. The dinoflagellate cyst data combined with the palaeomagnetic record, the radiometric dating of lavas, and the position of the diamictites and tuff layers allowed refinement of the previously proposed stratigraphical correlations between the Tjörnes area and the Flatey core. The deposition of the sequence from the Flatey core took place during the Matuyama, i.e. between 2.59 and 0.78 Ma, and several hiatuses are postulated. The Lower Pleistocene dinoflagellate cyst assemblages from the outcrop sample bear similarities to those recovered from fully marine subsurface samples on the northern shelf of Iceland within the Polar Front realm. Similar oceanographical conditions influenced by the Irminger Current and the East Icelandic Current can be inferred for Early Pleistocene times.     

The population geography of Australia: Trends and prospects

In this year of the Bicentenary of European settlement in Australia, it must be remembered that humans have been present in Australia for at least 40,000 years, longer than in the Americas or the Pacific island countries. The year 1788, however, marks a discontinuity in the population history and geography of Australia, and this review considers past trends and contemporary dynamics in order to illustrate the population issues confronting Australia in her Bicentenary year.     

The feeling of participation: Everyday spaces and urban change

Initiatives around ‘public participation’ and ‘community involvement’ have become increasingly central to UK government policy programmes, particularly within interventions aimed at disadvantaged neighbourhoods. These initiatives have been the subject of extensive critical comment, essentially focusing on the ways in which power is often maintained by state agencies, whatever the surrounding rhetoric. This article attempts to consider what more productive forms of participation might feel like, through drawing on fieldwork with two small community groups on housing estates in Stoke-on-Trent, UK, to look at how and why they were able to generate successful participation in their activities. The importance of the small-scale interactions and feelings that made up their spaces of participation is explored. These can be characterised through ideas such as ‘feeling comfortable’, ‘feeling at home’, ‘helping out’ and ‘keeping going’, and involve everyday sociability and informal forms of volunteering. If government is serious about supporting political participation in such contexts it needs to consider how official projects might learn from these kinds of spaces.     

Climate change impacts on environmental geosciences: Introduction

正Climate change and its impacts have become topical issues of global news, scientific research and conferences. Environmental Geosciences incorporate the various disciplines of geosciences and their multifaceted interactions with life. Research discussions on the interaction of climate change, geosciences and environment may often be blur, and Schmidt-Thoméet al.(2010) stated that"Often past climate changes that can be deduced from geological records may help in understanding the speed of potential climate change effects, i.e. how quickly have sea levels changed, how drastic has nature reacted to ups and downs in temperature, etc. These analyses of past events help in giving outlooks on potential changes in our living environment. It is also of important to understand the magnitude and potential effects of extreme events, such as droughts and floods".