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91.
Against the background of the current state of provision of drinking water and sanitation in the world — with one billion lacking safe water, and 2.2 billion not having adequate sanitation — this article argues that private participation is necessary. The most important issues for the management of water utilities in the 21st century are identified as mobilizing investment for the highly capital intensive operation of water supply and sanitation infrastructure, and achieving efficiency in the delivery of services. The article highlights the issues that need to be raised if private investment is to be seriously considered as an alternative. Case studies, especially from Latin America (Argentina, Chile, Peru, Bolivia), illustrate different modes of private participation, and possible reasons for successes and failures are discussed. The article stresses that regardless of the modality of private sector involvement, on‐going government regulatory responsibility in the water sector is crucial. It suggests that regulatory policy must go beyond just setting tariffs, to develop standards for drinking water quality and waste treatment, as well as other standards. In conclusion, the article recognizes that numerous and increasingly difficult challenges face utilities in fulfilling their responsibility to deliver drinking water of adequate quality, in sufficient quantity, and at affordable prices, as well as safe and sustainable disposal of wastewaters for members of urban and rural communities.  相似文献   
92.
Phylloscopus trochilus ), crossbills (Loxia spp.), and tree pipit (Anthus trivialis). The composition of the bird community did not vary significantly between the compared transects. Some species appeared to favour road–forest edges but this could not be confirmed with our data. These species were not the same as have been reported to favor clear-fellings–mature forest edges. Therefore, the edge effect does not seem to be the most important factor controlling relative bird densities immediately adjacent and further away from highways. The likelihood of avoiding the problems the highways are causing for bird density are been discussed.  相似文献   
93.
房屋建筑的震害矩阵计算与设防投资比确定   总被引:10,自引:0,他引:10  
本文包括两个内容:1研究了现有建筑的设防延伸率,给出了用设防延伸率计算震害矩阵的分析方法,并用框架、厂房的计算破坏比与包头西地震调查得到的破坏比进行了比较,二者基本吻合;2.通过咨询抗震设计专家,确定并给出了框架、砖结构、厂房的设防投资比。  相似文献   
94.
介绍了环保基金的形成和投资管理的方式方法等.  相似文献   
95.
对建立环保信托业的探讨   总被引:1,自引:0,他引:1  
根据我国环保产业和环保市场发展状况,结合信托经济的特点和规律,提出在环保投资、环保融资,环保租赁、环保产业合资合营等方面引入了信托机制的必要性和重要性。  相似文献   
96.
目前,城市污水处理厂的建设速度比较迟缓,地方政府建设城市污水处理厂积极性不高,针对这一现状,文章对城市污水处理厂的外部性和投资资金不足等原因进行了调查和分析,在城市基础设施建设资金不足的背景下,城市污水处理厂投资体制不能满足城市污水处理的需求,因此,城市污水处理厂的外部性和流域水污染防治的系统性要求中央政府承担建设城市污水处理厂的主要责任,另外,流域内社会经济发展的普遍不平衡,以及国外在城市污水处理厂投资方面的一些成功经验,都说明了中央政府投资城市污水处理厂的必要性。  相似文献   
97.
Fisher’s 1930 theory of sex allocation predicts a population-wide 1:1 ratio of parental investment. We tested this prediction in the European beewolf, a sphecid wasp that hunts for honeybees as larval food. Because the method to quantify parental investment is of crucial importance, we compared the suitability of several different investment measures. Female/male cost ratios were determined from a sample and the total investment in sons and daughters was calculated. In addition, the actual number of prey items for sons and daughters was directly determined by excavating nests and counting the cuticle remains of the prey. Though mortality was high (70%), it had only a weak effect on the estimate of the investment ratio. Based on commonly used measures like fresh and dry weight of emerged adults, the investment ratio did not deviate from Fisher’s prediction of equal investment. However, progeny weight considerably underestimates investment in males and investment in large progeny. Measures that reflect the allocation of resources more directly (amount of provisions, brood cell volume) revealed a significant male bias and thus contradicted Fisher’s theory. Three kinds of explanation are discussed. First, non-adaptive explanations are unlikely. Second, from the spectrum of alternative adaptive theories, only models that assume a non-linear relationship between amount of investment and progeny fitness seem to be relevant for the study species. Third, though the number of prey in a brood cell seems to be a rather good measure of parental investment in European beewolves, some problems in measuring parental investment remain. These problems are of broad significance. Received: 17 June 1999 / Received in revised form: 6 July 1999 / Accepted: 11 July 1999  相似文献   
98.
The past decades have seen planning and implementation of built infrastructure in all over the developed and developing world growing in large scales. This has been influenced by economic and population growths, urbanization and industrialization, which in turn have put increasing stress in provision of services. The paper reviews the policy dimensions of water infrastructure development and financing in the two largest economies at present, China and India, including planning, implementation and decision-making processes. Findings indicate that main challenges for infrastructure development have been limited sources of financing, but also policies and their implementation. The high levels of investment in water infrastructure in the two countries have been impressive, mainly in China. However, they still have not necessarily addressed efficiency over the long term, supported more inclusive and higher economic growth or improve social and environmental conditions in all cases.  相似文献   
99.
100.
The evaluation of mining and other natural resource projects is made particularly difficult by the high degree of uncertainty attaching to output prices. It is shown that the techniques of continuous time arbitrage and stochastic control theory may be used not only to value such projects but also to determine the optimal policies for developing managing. This paper describes a model for evaluating natural resource investments under uncertainty from a new perspective. The previous works in this field mostly regard the movements of natural resource prices as a continuous GBM process, which pays few attentions to the shock of unexpected bad news. Our model provides the first theoretical method to analyze the impact of such "jump" on investment decisions. It concludes that the more frequently bad news happens, the earlier a project will be invested.  相似文献   
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