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1.
Effect of reservoir flushing on downstream river water quality 总被引:1,自引:0,他引:1
The effect of short-term reservoir flushing on downstream water quality in the Geum River, Korea was studied using field experiments and computer simulations. The reservoir release was increased from 30 to 200 m(3)/s within 6 h for the purpose of this experiment. The flushing discharge decreased the concentrations of soluble nitrogen and phosphorus species considerably, but the experimental results revealed a negative impact on organic forms of nutrients and biochemical oxygen demand (BOD). A dynamic river water quality model was applied to simulate the river hydraulics and water quality variations during the event. The model showed very good performance in predicting the travel time of flushing flow and the variations of dissolved forms of nitrogen and phosphorus constituents. However, it revealed a limited capability in simulating organic forms of nutrients and BOD because it does not consider the re-suspension mechanism of these constituents from sediment during the wave front passage. 相似文献
2.
B. Bowonder 《The Environmentalist》1987,7(2):111-122
Summary Environmental problems in developing countries partly arise out of lack of development, hence they are intricately linked to the socio-economic conditions. Environmental awareness and environmental education are critical under these conditions but these are time consuming and slow solutions. Integration of economic and environmental plans for various regions have to be attempted systematically. Time is running out, and unless comprehensive steps are taken up some of the capital assets (such as forests, fresh water, soils, etc.) are likely to be irretrievably damaged.Dr B. Bowonder was, until recently, Chairman of the Centre for Energy, Environment and Technology at the Administrative Staff College, Hyderabad. He recently joined this Journal's Advisory Board and his analysis of the Bhopal Incident (The Environmentalist, 5 (2) 89–103) created considerable interest. He is currently a member of the United Nations Economic and Social Commission for Asia and Pacific. 相似文献
3.
We evaluated the relationships between landscape characteristics and lake water quality in receiving waters by regressing four water quality responses on landscape variables that were measured for whole watersheds and three different buffer distances (30, 60, and 120 m). Classical percolation theory was used to conceptualize nutrient pathways and to explain nonlinear responses. The response variables were total nitrogen (TN), total phosphorus (TP), chlorophyll-a (Chl-a), and Secchi transparency (SD). Landscape data were obtained from satellite image-derived maps of 130 watersheds in Iowa using geographic information systems software. We developed regression models with a stepwise protocol selecting the optimal number of significant explanatory variables. Configuration variables such as contagion, the cohesion of cropland and urban land, and the aggregation index of forest were very important and more important than variables assessing landscape composition (e.g., percentage farmland). Whole watershed models predicted between 15 and 67% of the variability in TN, TP, Chl-a, and SD. Proximity-explicit data offered only slightly improved statistical power over land cover data derived from the entire watershed for variables TN, Chl-a. and SD, but not for TP. 相似文献
4.
Cooking is the major energy end use in most developing countries. A general model to calculate energy-use cost for cooking with 15 combinations of fuel and end use device based on prevailing market conditions is proposed by this paper. The model has been implemented to develop an independent computer software which ranks the combinations on the basis of least cost. The model reflects cooking energy consumption patterns in urban Nepal, where it was tested. The results suggest that biomass energy used in efficient stoves is the most attractive option for cooking in Nepal. Hence, a policy for effective use of biomass is necessary . 相似文献
5.
Mohan Munasinghe 《Natural resources forum》1990,14(3):193-209
This paper focuses on improving efficiency in the water and sewerage sectors through long-run marginal cost pricing, adjusted for financial needs, externalities, second best considerations, lifeline tariffs and cross subsidization within an integrated water resource planning (IWRP) framework. Supply efficiency suggests that for a given price structure, an optimal long-run investment plan and a corresponding level of supply quality should be determined which maximizes net social benefits. Supply efficiency also requires efficient operation of the water system, including optimization of losses. 相似文献
6.
François Munoz Franz Bogner Pierre Clement Graça S. Carvalho 《Journal of environmental psychology》2009
By using an original framework involving complementary statistical approaches, we investigated the environmental attitudes of 6379 pre-service and in-service teachers in 16 countries of Europe and its neighbourhood. To test hypotheses about the nature of environmental attitudes, we examined the variation across groups of individuals (between-class analysis), investigated the independent effects of several candidate explanatory factors (orthogonal analysis), and finally inspected potential relationships between conceptions on a variety of topics (co-inertia analysis). 相似文献
7.
John E. Tilton 《Natural resources forum》1989,13(3):198-203
In the early years after World War II the developed countries, and in particular the USA, acounted for a large portion of world metal consumption. Since that time a shift in consumption has occurred favouring the industrialized states of Western Europe, the centrally planned economies of Eastern Europe, and more recently Japan and the other Pacific Rim countries of Asia (PRA). After assessing the magnitude of the shift in metal consumption toward the PRA countries, this paper focuses on differences in economic growth, the nature of trade, and other factors responsible. Finally, the implications of the shift are considered for the nature of metal trade, the competitiveness of metal exporting countries, the structure of international metal markets, and the future availability of metal supplies. 相似文献
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9.
Matheus Koengkan 《The Environmentalist》2018,38(3):415-425
The impact of consumption of renewable energy on CO2 emissions was investigated, in five MERCOSUR’s countries from 1980 to 2014. The autoregressive distributed lag (ARDL) in the form of Unrestricted Error Correction Model to decompose the total effect of variables into it is the short- and long-run components. The results of preliminary tests showed the presence of cross-sectional dependence between the variables, the stationarity of all variables in the first differences, and the homogeneity in panel data. Moreover, the specification tests pointed to the presence of cross-sectional dependence, non-correlation between the crosses, serial correlation in the panel data model, and the existence of heteroskedasticity. The results of semi-elasticities (short run) and elasticities (long run) of ARDL model pointed that the economic growth and consumption of fossil fuels increase the CO2 emissions in the short and long run, while the consumption of renewable energy reduces them. Despite the consumption of renewable energy reducing the environmental degradation in the MERCOSUR countries, its impact is small. Finally, this study proved that the consumption of renewable energy is able to reduce the CO2 emissions, which is responsible for the environmental degradation in the MERCOSUR countries, and that the economic growth of these same countries increases the CO2 emissions, along with the fact that all MERCOSUR countries are highly dependent of fossil fuels. 相似文献
10.
This paper presents a critical assessment of the existing Lebanese industrial sector, namely the current status and classification of industrial establishments based on a comparative synthesis and analysis of recent nationwide surveys and studies pertaining to industrial-waste management. Characterisation of solid and liquid industrial wastes generated, including hazardous wastes, is presented together with current and projected waste loads, recycling opportunities, and export/import practices. Institutional capacity and needs pertaining to the enforcement of relevant environmental legislation, staffing and resources, monitoring schemes, and public participation are critically evaluated. Finally, realistic options for industrial-waste management in the context of country-specific institutional economic and technical limitations are outlined. The industrial sector in Lebanon consists of small-scale industries (84% employ less than 10 persons), primarily involved in light manufacturing (96%). These industries which are distributed among 41 ill-defined zones and deficient in appropriate physical infrastructure, generate solid, liquid, and hazardous waste estimated at 346,730 tons/year, 20,169,600 m3/year and between 3000 to 15,000 tons/year, respectively. Although the growth of this sector contributes significantly to the socio-economic development of the country (industry accounts for 17% of the gross domestic product), in the absence of a comprehensive environmental management plan, this expansion may not be sustained into the coming millennium. The anticipated expansion will inevitably amplify adverse environmental impacts associated with industrial activities due to rising waste volumes and improper waste handling and disposal practices. These impacts are further aggravated by a deficient institutional framework, a lack of adequate environmental laws, and lax enforcement of regulations governing industrial-waste management. 相似文献
11.
Donald I. Bleiwas 《Natural resources forum》1990,14(1):2-13
The US Bureau of Mines has determined the potential availability of nickel from 36 deposits or districts in 16 market economy countries (MECs). More than 95% of production in MECs was analysed. The study indicates the quantity of nickel available in resources and potential annual production at net production costs and on a total cost basis with a 0% and a 10% discounted cash flow rate of return (DCFROR). The properties included in this study contain approximately 33 million tonnes of recoverable nickel. About 26 million tonnes of nickel is potentially recoverable from nickel laterite deposits, of which 4.5 million tonnes can be produced at $2.50/lb or less with a 0% DCFROR. Approximately 7 million tonnes of nickel is potentially recoverable from nickel sulphide deposits of which about 6.3 million tonnes could be produced at $2.50/lb or less at a 0% DCFROR. Sensitivity studies indicate that the total cost of producing nickel from laterite deposits is most sensitive to increases in energy costs, and that the total costs of producing nickel from sulphide deposits is most sensitive to increases in labour costs and by changes in byproduct revenues. 相似文献
12.
Agricultural development has been an effective instrument for poverty alleviation and economic development in developing countries over the latter half of the twentieth century, and over 80 % of rural people globally still depend on agriculture for their living. However, issues such as water availability, land degradation and an increasing dependence on chemical fertilisers and pesticides continue to be on-going threats to sustainable agricultural development. These threats are being driven by the pressing need to ensure food security in the face of rapidly growing and urbanising populations. Developing countries will therefore continue to need improved methods for planning sustainable agricultural development. This paper presents a review of agricultural sustainability assessment in developing countries. The review highlights some of the key weaknesses that persist in sustainability assessment and the need to consider not only indicators of sustainability but also the drivers that influence indicator behaviour. We argue that without a good understanding of the drivers of sustainability and their systemic relationships to indicators, sustainability assessments run the risk of focusing on symptoms without addressing underlying causes of adverse indicator trends. Drivers of agricultural sustainability in developing countries encompass a range of demographic, natural, socio-economic, political, institutional and management factors. Understanding these and their relationships to sustainability indicators is needed in order to develop agricultural development policy that supports sustainability. The paper presents a conceptual framework for guiding systemic agricultural sustainability assessment and agricultural development planning in developing countries that includes both sustainability indicators and drives, and considers the broad relationships between them. 相似文献
13.
Farmers attempting to subsist in tropical uplands often rely upon unsustainable resource use practices that lead to soil erosion, declining crop yields, and a loss of soil productivity capacity. Other uses of tropical uplands, including logging and conversion of forest to rangelands, have similar results. The undesirable effects of these actions are felt on-site, at the watershed level, and even nationally. Ecological cause-effect relationships are poorly understood, and few examples exist of the successful integration of ecological knowledge with upland development. It is hypothesized that recent results of ecological research could be applied to uplands management so that stable sustainable systems of human use may be established. A second hypothesis is that statistically reliable data can be obtained from experiments in upland situations, although natural variations of soils, weather, and vegetation are great. To test these hypotheses, research involving multinational collaboration among American and Southeast Asian scientists has begun. The objective of the work is to provide credible quantitative information to help policy and decision makers and resident farmers to plan and implement improved practices based on ecological principles.Some findings to date include:
相似文献
1. | Ecological principles are difficult to relate to the practical context of upland agroecosystems. Indeed, the null hypothesis is necessary for planning experiments and demonstrations. |
2. | The signal-to-noise ratio in these field experiments is low, and the detection of changes due to human intervention in soil erosion, nutrient movement, and plant productivity is difficult. |
3. | Obstacles to field research in developing countries include logistic, cultural, political, and institutional factors. It is essential that local land managers participate from the start with scientific researchers in designing experiments. |
4. | Planned collaboration among academic and government scientists facilitates design of relevant research and the implementation of results. |
5. | The idea of ecologically based management has been well received by researchers and government officials in Asia. There is little argument with the logic of the approach. |
6. | Pressures for quick responses to urgent problems in the uplands conflict with the need for careful, long-term, statistically valid scientific research. |
7. | Ecological principles are vaguely understood and poorly articulated in the scientific literature. The transfer and application of ecological science to the developing world would be enhanced by clearer statements of principles. |
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15.
Johnson DM Hokanson DR Zhang Q Czupinski KD Tang J 《Journal of environmental management》2008,88(3):416-427
Water scarcity is threatening social and economic growth in rural areas of developing countries. There are potential markets for water purification technologies in these regions. The main focus of this article is to evaluate the social, economic and political feasibilities of providing water purification technologies to rural areas of developing countries. The findings of this research can serve as the basis for private investors interested in entering this market. Four representative regions were selected for the study. Economic, demographic, and environmental variables of each region were collected and analyzed along with domestic markets and political information. Rural areas of the developing world are populated with poor people unable to fulfill the basic needs for clean water and sanitation. These people represent an important group of potential users. Due to economic, social, and political risks in these areas, it is difficult to build a strong case for any business or organization focusing on immediate returns on capital investment. A plausible business strategy would be to approach the water purification market as a corporate responsibility and social investing in the short term. This would allow an organization to be well positioned once the economic ability of individuals, governments, and donor agencies are better aligned. 相似文献
16.
《Resources, Conservation and Recycling》2006,46(1):1-26
To deal with the complexity of recycling, a wide variety of models have been developed, each serving a specific purpose. Despite the current trend increasing international trade in recycling-related material flows, the international dimension of physical and economic relationships in recycling is often ignored in current models and analyses. This paper develops a formal model of an international material-product chain (MPC) that represents the mechanism behind international recycling. The attention is focused on the case of a developed and a developing country that exchange material commodities, final products and recyclable waste. Among others, the model demonstrates that taking into account environmental externalities results in higher levels of recycling. Moreover, we show that international recycling is mainly driven by regional differences in the quantity and quality of factor endowments and economic efficiency of recycling. Given that industrialised countries are relatively well endowed with recyclable waste, the recovery rate usually exceeds the utilisation rate. In developing countries, an opposite pattern is observed. 相似文献
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18.
Mehdi Shafaeddin 《Resources Policy》1990,16(4)
This article explains that the nature of commodity price determination and the characteristics of the link between commodity prices and prices of manufactured goods are such that they have an inflationary and recessionary impact on the world economy. Subsequently, it argues that International Commodity Price Agreements (ICAs) and the Common Fund are not only in the interest of developing countries but are also in the vital interest of developed countries. They assist in stabilizing economic activities and sustaining recovery at a higher rate of growth of output and employment in these countries. Nevertheless, to be effective for these purposes, ICAs should cover a wide range of commodities and adequate financial resources should be available to the First Account of the Common Fund. 相似文献
19.
Stephens M Kambani 《Natural resources forum》1995,19(2):107-112
Attracted by the high unit value and low barriers to entry in terms of capital requirements, technology, infrastructure, minimum reserves and implementation time, the artisanal and small-scale mining of high unit value minerals, such as gemstones, diamonds and gold, has grown to significant proportions in developing countries. This is manifested by the value of output and large numbers of miners engaged in this activity. Despite the expansion of the subsector, its national economic role in many developing countries has largely been disappointing, primarily due to high levels of illegal trading activity. The objectives of this paper are to identify major factors responsible for the declaration problem. The economic impact of such activities is pointed out. To conclude the discussion, options are presented that provide a basis for eliminating illegal marketing practices and thereby strengthening the economic role of the subsector in meeting national development objectives of developing countries . 相似文献
20.
The demand for energy services is growing rapidly in developing countries. Low levels of energy efficiency in electric power supply and in energy use mean that the energy sector threatens to absorb an intolerably high share of available financial resources. Energy inefficiency also contributes to local and global environmental problems. A strategy of vigorously improving energy efficiency is thus a key element of a sustainable development path. Results reported in this paper show that there is considerable room for efficiency improvement in both existing and new capital stocks, but a much larger effort than presently underway is essential if the potential is to be realized. Assistance from the industrialized countries can play a major role in such an effort. 相似文献