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451.
452.
Liquan Zhang Zhanguo Gao Richard Armitage Martin Kent 《Frontiers of Environmental Science & Engineering in China》2008,2(2):187-197
The spectral reflectance of recently formed salt marshes at the mouth of the Yangtze River, which are undergoing invasion
by Spartina alterniflora, were assessed to determine the potential utility of remotely sensed data in assessing future invasion and changes in species
composition. Following a review of published research on remote sensing of salt marshes, 53 locations along three transects
were sampled for paired data on plant species composition and spectral reflectance using a FieldSpec™ Pro JR Field Portable
Spectroradiometer. Spectral data were processed concerning reflectance, and the averaged reflectance values for each sample
were reanalysed to correspond to a 12-waveband bandset of the Compact Airborne Spectral Imager. The spectral data were summarised
using principal components analysis (PCA) and the relationships between the vegetation composition, and the PCA axes of spectral
data were examined. The first PCA axis of the reflectance data showed a strong correlation with variability in near infrared
reflectance and ‘brightness’, while the second axis was correlated with visible reflectance and ‘greenness’. Total vegetation
cover, vegetation height, and mudflat cover were all significantly related to the first axis. The implications of this in
terms of the ability of remote sensing to distinguish the various salt marsh species and in particular the invasive species
S. alterniflora were discussed. Major differences in species with various physiognomies could be recognised but problems occurred in separating
early colonising S. alterniflora from other species at that stage. Further work using multi-seasonal hyperspectral data might assist in solving these problems. 相似文献
453.
Chandra Pandey 《中国人口.资源与环境(英文版)》2013,11(3):199-209
Few other policy zones are as complex as the issue of climate change. If the more pessimistic projections of climate change doom are correct, then the failure to address the issue is likely to be catastrophic and irreversible. The Inter-governmental Panel on Climate Change has predicted the potential extinction of many species and that the existence of small-island and other vulnerable countries will be threatened if business-as-usual greenhouse gas emissions continue. Climate change is a transboundary problem and requires unprecedented levels of cooperation between states and serious and sustained responses from major emitters. However, the growing demand and consumption of natural resources for continued energy security and cornucopian economic growth have undermined the outcomes of international climate change negotiations. It is argued here that there is a strong connection between the major emitters’ positions at United Nations’ climate talks, their possessions, dependence and consumption of natural resources, and the continued undermining of international climate change policy for unsustainable growth. This paper assesses the resource politics of the US, China, India, Canada, Russia, and Saudi Arabia and their positions at climate talks to show the link between lack of climate change policy progress and the positions of these main players. 相似文献
454.
Abstract Land-use change is an important aspect of global environment change. It is, in a sense, the direct result of human activities influencing our physical environment. This paper analyzed the land- use change in Northeast China during 1985–2000 based on Landsat TM images. It divides Northeast China into five land-use zones based on the dynamic degree model of land-use: woodland/grassland-arable land conversion zone, dry land-paddy field conversion zone; urban expansion zone, interlocked zone of farming and pasturing and reclamation and abandon zone. The findings include the obvious increase of cropland area, paddy field and dry land increased by 75 and 276 thousand hm2 respectively; urban areas expanded rapidly, areas of town and rural residence increased by 76.8 thousand hm2; areas of forests and grassland decreased sharply with the amounts of 1399 and 1521 thousand hm2 respectively; areas of water body and unused land increased by 148 and 514 thousand hm2 respectively. This paper also discusses the driving forces in each land-use dynamic zone and finds that some key biophysical factors affect conspicuously the conversion of different land-use types. The relation between land-use conversion and DEM, accumulated temperature (≤10°C) and precipitation was analyzed and represented. The land-use changes In Northeast China resulted from the changing macro social and economic factors and local physical elements. Rapid population growth and management changes can explain the shaping of woodland/grassland-cropland conversion zone. The conversion from dry land to paddy field in the dry land-paddy field conversion zone, apart from the change of physical elements promoting the expansion of paddy field, results from two reasons: one is that the implementation of market economy in China has given farmers the right to decide what and how they plant their crops, the other factor is originated partially from the change of the dietary habit along with the social and economic development. The conversion from paddy field to dry land is caused primarily by the shortfall of irrigation water, which in turn is caused by poor water allocation managed by local governments. The shaping of the reclamation and abandon zone is partially due to the lack of environment protection consciousness among pioneer settlers. The reason for the conversion from grassland to cropland is the relatively higher profits of farming than that of pasturing in the interlocked zone of farming and pasturing. In Northeast China, the rapid expansion of built-up areas results from two factors: the existence of a small number of towns and the huge potential for expansion of the existing towns and cities. The urban land expanded mainly in areas with a gentle topographic relief and low population density. 相似文献
455.
Li Fuzhu 《中国人口.资源与环境(英文版)》2013,11(4):59-63
Abstract Human Capital Theory came into being in the middle and later periods of the 20th century. A lot of achievements have been made on the research in its connotation, measures of the value, investment and income, function mechanism and so on, by foreign scholars. In recent 10 years of the new Millennium alternation, the “steal business effect” and the structure of human capital on the mechanism of economic rise has become the two emphasis in current foreign Human Capital Theory's research. On the basis of foreign researches and Chinese situations, domestic scholars have enriched and developed it, but there are many disparities in its methods, aspects and levels between foreign and domestic researches. 相似文献
456.
我国实施西部大开发战略后,西部水资源开发利用问题变得越来越突出.为了弄清楚西部水资源开发利用存在的风险现状,本文在风险概念的基础上探讨了水资源开发利用风险概念和影响因素,并构建了西部水资源开发利用风险评价指标体系.根据水资源系统表现出多模态、突跳和发散的基本突变特征,论述了运用突变理论评价水资源开发利用风险具有一定的可行性,将突变理论引入到水资源开发利用风险评价中,对西部水资源开发利用风险进行评价.首先对各项风险评价指标按照重要性排序,并对各指标值进行无量纲化;然后利用突变模型的归一公式和突变模型的评价准则进行递归运算,最后求出各层指标相对风险值(突变隶属度),将评价结果与风险等级对照,综合判断和分析各层各项指标相对风险状况.计算结果表明:在西部12个省份中,各层指标的风险值差异显著,但是水资源开发利用综合风险值分布在0 66-0.92之间,总体上属于中高度风险水平,12省份风险从小到大排序为:西藏→陕西→重庆→四川→青海→云南→贵州→广西→内蒙→甘肃→新疆→宁夏,这一结果与西部12省份水资源开发利用实际状况相符,可以为西部大开发过程水资源合理有效利用和管理提供风险决策参考依据. 相似文献
457.
Abstract China has won the name of the world factory being famous for exporting a great deal of and various kinds of low-price merchandise. However, most of Chinese exports are primary goods or manufactured products that create heavy pollution and require intensive use of resources. Chinese products go abroad, but their following harms stay behind. The article analyzes many obvious low-price facts in China and their concomitant terrible environmental results in detail, and points out that there are huge hidden troubles in the way of China's sustainable development behind her seemingly flourishing economy. 相似文献
458.
Abstract> Two prevalent views are reviewed on China’s urbanization firstly. Then, this article highlights the characteristics and pattern of urbanization in the world based on the quadrants map, using data of 118 countries or areas. The results indicate that the process of urbanization in the world excluding the data of China has slowed down gradually. A further exploration examines China’s urbanization process and economic development over time, which reveals that both urbanization level and the level of economic development belong to the low-grade coordination pattern. The low level of urbanization is closely connected with the low level of economic development. Actually, China’s urbanization gap appeared during 1985–1995, but it has been eliminating this urbanization gap since 1995 as a result of rapid urbanization growing. The complicated realities revealed in this analysis challenge the existing two prevalent views. 相似文献
459.
ABSTRACTContinuously reducing the CO2 intensity of GDP is the core strategy for developing countries to realize the dual targets of economic growth and CO2 emissions reduction. The measures are twofold: one is to strengthen energy saving and decrease energy intensity of GDP and the other is to promote energy structural decarbonization and reduce CO2 intensity of energy consumption. In order to control global temperature rise no more than 2°C, the decrease in CO2 intensity of GDP needs surpass 4% before 2030, but it could be merely about 2% based on the current trend. Therefore, all countries ought to speed up the low-carbon transition in energy and economy. As for China, keeping a continuous decline in CO2 intensity of GDP of 4%–5% will ensure the realization of the NDC objectives, and also promotes the early peaking of CO2 emissions before 2030. China will play a positive leading role in realizing a win-win low-carbon development coordinating sustainable development and climate change mitigation. 相似文献
460.
David G. Victor 《中国人口.资源与环境(英文版)》2013,11(3):181-185
ABSTRACTScholars and practitioners have focused in recent years on the potential for achieving cooperation in small “clubs” of countries. While solutions to global climate change will eventually require widespread cooperation, club strategies could help to catalyze that outcome. Unlike the Paris Agreement, which has achieved widespread but relatively shallow cooperation, it could be easier to tailor agreements that allow deep cooperation within smaller groups. This essay extends that logic to clubs whose geometry varies two-dimensionally across countries but also along a third dimension: within countries. Most of the key elements of international relations and international law theory that explain how clubs achieve cooperation are directly applicable to three-dimensional clubs. Most of the relevant experience for these clubs has occurred in the west; overdue is a close assessment of how key units – such as provinces and firms – within China and other emerging economies. 相似文献