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391.
392.
Unusual Salinity Conditions in the Yangtze Estuary in 2006: Impacts of an Extreme Drought or of the Three Gorges Dam? 总被引:1,自引:0,他引:1
During the extreme dry year of 2006, abnormal salinity conditions in the Changjiang Estuary of the Yangtze River occurred
in partial coincidence with the second impoundment phase of the TGD (Three Gorges Dam). Analysis of discharge observations
in the upper reaches of the estuary and of salinity observations in the estuary as a whole reveals that in 2006 salinity was
over 100 mg/l during 275 days, over 250 mg/l during 75 days and over 400 mg/l during 48 days. It is well known that this is
due to extreme low discharges from the upper catchment area into the estuary. Moreover, large amounts of water consumed along
the lower reaches of the Yangtze River can also aggravate the low discharges that lead to stronger saltwater intrusion in
the estuary. Of the 75 days that salinity was over 250 mg/l, the low discharge was decreased further by 10 to 20% due to water
consumption. The additional impact of the impoundment phase of the TGD (lasting 37 days in autumn) was noticeable only during
7 days in 2006. During that period, the relative contributions of the TGD and the water consumption in the lower reaches of
the Yangtze River amounted to 70 and 30%, respectively. It may be concluded that the impact of the second impoundment phase
of the TGD on salinity intrusion in the estuary was modest, while the extreme drought of 2006 was the dominant cause. 相似文献
393.
Candice Stevens 《Natural resources forum》2010,34(1):16-23
Achieving sustainable development depends on comprehensive approaches which integrate consumption and production initiatives. At present, sustainable consumption is being overemphasized to the neglect of the more important production side. This paper examines the role of governments in promoting sustainable consumption and production to identify gaps in national schemes which reduce their overall effectiveness. Public policy tools promoting sustainable consumption and production are discussed in terms of whether they are aimed at correcting: 1) market failures (regulations, taxes, subsidies); or 2) systems failures (labels, communications, education, public procurement). The challenge for governments is to link sustainable consumption initiatives to policies aimed at increasing the sustainability of production in the private sector in both their national and international dimensions. In this way, governments can enlist the aid of consumers in pushing producers towards sustainability and to achieve the ultimate goal of sustainable development. 相似文献
394.
395.
A new and integrated hydro-economic accounting and analytical framework for water resources: a case study for North China 总被引:1,自引:0,他引:1
Water is a critical issue in China for a variety of reasons. China is poor of water resources with 2300m(3) of per capita availability, which is less than 13 of the world average. This is exacerbated by regional differences; e.g. North China's water availability is only about 271m(3) of per capita value, which is only 125 of the world's average. Furthermore, pollution contributes to water scarcity and is a major source for diseases, particularly for the poor. The Ministry of Hydrology [1997. China's Regional Water Bullets. Water Resource and Hydro-power Publishing House, Beijing, China] reports that about 65-80% of rivers in North China no longer support any economic activities. Previous studies have emphasized the amount of water withdrawn but rarely take water quality into consideration. The quality of the return flows usually changes; the water quality being lower than the water flows that entered the production process initially. It is especially important to measure the impacts of wastewater to the hydro-ecosystem. Thus, water consumption should not only account for the amount of water inputs but also the amount of water contaminated in the hydro-ecosystem by the discharged wastewater. In this paper we present a new accounting and analytical approach based on economic input-output modelling combined with a mass balanced hydrological model that links interactions in the economic system with interactions in the hydrological system. We thus follow the tradition of integrated economic-ecologic input-output modelling. Our hydro-economic accounting framework and analysis tool allows tracking water consumption on the input side, water pollution leaving the economic system and water flows passing through the hydrological system thus enabling us to deal with water resources of different qualities. Following this method, the results illustrate that North China requires 96% of its annual available water, including both water inputs for the economy and contaminated water that is ineligible for any uses. 相似文献
396.
以电力能源为研究对象,选取2014—2018年中国家庭追踪调查(CFPS)与能源价格扭曲指标的匹配数据,从微观家庭层面经验考察了居民能源价格扭曲对家庭消费的影响及其作用机制。结果表明:(1)普遍存在负向扭曲的居民电力价格提升了居民家庭消费水平,特别是增加了居民家庭的电能、食品、衣着鞋帽、设备及日用品、交通通信、文教娱乐及其他分项消费支出。(2)居民能源价格扭曲通过收入效应与互补效应影响居民家庭消费水平及其结构。(3)居民能源价格扭曲的家庭消费效应在城乡家庭之间、城乡各收入组家庭之间存在异质性。居民能源价格扭曲对农村家庭消费水平的促进作用比城镇家庭更大,同时,居民能源价格扭曲对城乡家庭消费的促进作用都体现在提高各自高收入组家庭消费。这些结论可为推进能源市场化改革并建立公平与效率兼容的能源价格机制提供决策参考。 相似文献
397.
398.
以超声波(US)和Fenton试剂联用对氯苯(CB)的脱氯降解作用进行了研究.采用单因素法,重点考察了Fenton试剂配比(n(H_2O_2):n(Fe~(2+)))、Fenton试剂用量、CB初始浓度、溶液初始pH值和超声波功率等因素对脱氯降解效果的影响,研究了CB浓度与反应时间的变化关系.结果表明,US/Fenton试剂对CB具有良好的脱氯降解作用,当CB初始质量浓度为100 mg·L~(-1)、H_2O_2与Fe~(2+) 的物质的量比为40:1、H_2O_2的浓度为10 mmol·L~(-1)、溶液初始pH值为3、超声波功率为250 W时,CB脱氯率最大可达93.5%.US/Fenton试剂对于CB的脱氯降解反应符合1级衰减模型,速率常数k'=0.266 min~(-1). 相似文献
399.
Throwing products away before they fail or are broken is at the heart of consumer behaviour in developed economies such as the UK. Products are often discarded for reasons of fashion, or to keep up with technological advances, rather than because they have reached the end of their functional life. Such behaviours contribute to resource depletion, greenhouse gas emissions, and physical waste which needs to be managed. Extending the length of time that products are kept in use (whether by their original or subsequent owners) can contribute to greater resource efficiency, with significant potential to reduce greenhouse gas emissions. This research was undertaken to support the development of evidence-based policy in the UK on the role of longer product lifetimes in achieving sustainable consumption and waste prevention. Twelve qualitative discussion groups, involving 115 consumers, were carried out to explore consumer influences on product lifetimes including: which factors influence purchase decisions; the care of products in use; and disposal decisions. A new typology was developed to describe how products meet consumers’ various needs for ‘workhorses’, ‘investment’ and ‘up-to-date’ products; and how lifetime is an outcome of the ‘nature’ of a product (functional life) and its ‘nurture’ (lifetime in use) by consumers. The results demonstrate that consumers have come to expect constant and rapid up-dating of products. In particular, having the latest versions of products is strongly associated with personal identity and feelings of success in life. There is little evidence of concern about the environmental consequences of a ‘throwaway society’. The low cost of new products, which enables rapid updating for reasons of fashion, is a key barrier to encouraging consumers to keep products in use for longer. Some opportunities were identified however for certain ‘workhorse’ and ‘investment’ products that are valued more for their functionality than fashion. 相似文献
400.
江西省城市化进程中资源消耗特征及响应分析 总被引:1,自引:0,他引:1
刘耀彬 《中国人口.资源与环境》2007,17(6):50-53
选取能源消费总量、总用水量和城市建成区面积作为江西省资源消耗的指示性指标,在对其城市化进程中资源消耗特征分析的基础上,采用计量经济学的方法。对城市化作用的资源消耗响应情景进行了模拟。研究显示:①随着城市化进程的推进,江西省资源消耗特征表现并不一致。其人均能源消耗、人均建成区面积扩张有着与全国类似的逐步增长的态势,但其人均值都低于全国人均水平;而人均用水量则与全国一样呈现下降趋势,但江西省人均用水量一直都高于全国平均水平。②格兰杰因果分析发现,江西省城市化水平变化是人均能源消费增长和人均建成区面积扩张的格兰杰因果原因,人均建成区面积扩张也是城市化水平提高的格兰杰因果原因;而城市化水平变化与人均用水量下降互不为格兰杰因果原因。进一步的脉冲响应函数模拟表明:在江西省城市化进程中,城市化水平的提高对人均能源消费具有正的冲击效果;而人均建成区面积扩张对城市化具有先正后负的响应情景。 相似文献