The development of a waste discharge charge system (WDCS) in South Africa has been proposed to promote waste reduction and water conservation. The WDCS is based on the polluter pays principle and is designed such that the management of waste discharges achieves resource quality objectives (RQOs) at the minimum total cost to the catchment. Two charges are distinguished: first a charge for optimising use of the resource (incentive charge); and secondly, a charge for development and operation of mitigation measures in the resource (mitigation charge). The WDCS is applied to both point sources and non-point sources (NPS) of contamination. In the inclusion of NPS, the charge system distinguishes between registered and non-registered NPS, with the charge applied to the former group only, in the first instance. This paper introduces the WDCS by describing the principles and the theoretical basis of the WDCS, highlighting the link to RQOs as the benchmark of acceptable externalities. The paper explores the inclusion of NPS in the WDCS, describing: first, the principles of NPS inclusion in the WDCS; secondly, the types of NPS included in the present version of the WDCS; thirdly, the methodology for charge estimation; and finally, non-registered NPS and their potential inclusion in future editions of the WDCS. The paper concludes with remarks and challenges facing the first edition of the WDCS. 相似文献
A simple one-dimensional model that can evaluate the transport and fate of nitrogen in wetland soil-vegetation systems was developed to calculate the nitrogen-removal efficiencies of reed-bed wetlands. A common wetland plant, Phragmites australis, was the focus of this study. Seasonal variations of temperature, seasonal changes of nitrogen uptake by vegetation, the vertical distribution of root biomasses and oxygen transport into the soil by vegetation were considered in the model. Field observations were conducted to determine some model parameters and to validate the model, although most of the parameters were adopted from data published in Europe and North America. Field observations were carried out at the Minuma-Tanbo wetland (35 degrees 52' N, 139 degrees 43' E) in Japan. The calculated concentrations of NH4-N in the soils were about 10 times larger than those of the observational results. On the other hand, calculated NO3-N concentrations were about half of the observational data. However, the calculated nitrogen-removal efficiencies indicated the same trends as previous studies. It was found that the hydraulic loading rate played a key role in relation to nitrogen removal and nitrogen transformation in reed wetland systems. 相似文献
Summary The article gives a physical-economic interpretation to a number of economic North-South interdependent relations. Basic research evidence at the man-machine level was an inspiration; the output could only be expressed in physical specification terms. The corresponding generalizations are in product complexity, speciality terms also. This terminology is conducive to far-ranging extrapolations and generalizations. It eliminates the problem of pricing at the product level for all aggregation levels; therefore the fundamental economic relations are better expressed. The article concludes with a mega extrapolation in graphical terms, which relates the product and implied technological capability in the world, expressed in physical terms, for country groups ordered by three development levels. Correspondingly the comparative advantage and inter-industry trade areas at the world product level are shown.The author acknowledges valid comments of two anonymous referees and financial support by DGIS to the Technology Scientific Foundation for the research of which this paper reports certain aspects only. This paper came out as a working paper TSF 84-1. An earlier version was presented at the International Economic Association Meeting in Madrid, Sept. 1983. Clearly, only the author bears responsibility for the ideas and interpretations presented in the following text. 相似文献
Many parts of Japan have experienced rapid urbanization and industrialization over the past 50 years. This trend resulted in severe water pollution in many urban areas. To address the pollution problems, several measures such as construction of sewerage systems and enactment of laws and regulations have been undertaken. Because of these measures, the water quality has been improved to some extent. However, many water quality concerns still remain and are attributed in part to diffuse pollution. In this paper, historical progress, present situation and future aspects of diffuse pollution problems in Japan are reviewed. It is noted that solving diffuse pollution problems will require a combination of several measures including application of conventional treatment technologies and natural purification systems, implementation of appropriate policy measures, and promotion of citizen participation. 相似文献
This study uses unit-record data on over 50,000 rural children, from the sixteen major states of India, to analyse the determinants of the risks of severe stunting and of being severely underweight. The importance of this study derives from the fact that the prevalence of under-nourishment in India is, even relative to other poor countries, shockingly high. The study focuses on the role of maternal literacy in reducing the risk of child malnourishment. It concludes that when the mother is literate, real benefits flow to children in terms of reduced risk; the same benefits, however, do not flow when the father, but not the mother, is literate. Literate mothers make more effective use of health-care institutions, like anganwadis and hospitals. Consequently, the benefits to children from expanding the supply of such institutions are greater when these institutions interact with mothers who are literate.
Conclusion The presently existing methods or calculating seepage in inclined ASEs have a limited area of use and often give substantial deviations from the actual values. At the same time, no analytical relations are known for calculating Iex in the backwater zone of the LP. The formulas proposed in the article permit determining all main parameters of the seepage flow, including separately for the zones of effluent seepage and backwater of the LP, with an accuracy sufficient for engineering calculations.Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 9, pp. 33–36, September, 1992. 相似文献