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71.
ABSTRACT: The contribution of agriculture to nitrate pollution of 8Urface and ground water is a growing concern throughout the world. The objective of this article is to evaluate the current environmental policy governing nitrate contamination of ground water in the South Platte alluvial aquifer. In particular, the “best management practice” approach is assessed in its relationship to optimal policy design. First, the current physical environmental problem and existing institutional arrangements are described. Second, legal and economic criteria are brought to bear on the question of appropriate policy design. Finally, the strengths and weaknesses of the existing policy are evaluated in this context and changes in policy that would increase effectiveness are recommended. Considerable justification is found for state-initiated control because victims of ground water pollution are dispersed and risk assessment is technically demanding. However, ex post elements of existing policy must be improved, perhaps through targeting and some devolution in monitoring and enforcement responsibilities.  相似文献   
72.
Sources of Deforestation in Tropical Developing Countries   总被引:8,自引:0,他引:8  
/ Key causes of tropical deforestation are investigated using cross-sectional data for 90 developing countries for the period 1981-1990. Regression results reveal that deforestation is associated with both development and scarcity. Deforestation accelerates with expanding infrastructure, trade, debt, investment in the human capital base, and resource-based economic expansion. On the other hand, absolute and relative scarcities-manifested by growing population pressures, food and land shortages, fuelwood dependency, and inequalities in access to land-are also key factors explaining forest loss. Thus, results point to a fundamental environmental conundrum: Development is required if countries are to alleviate scarcity-driven forms of forest exploitation but is itself a major cause of deforestation. Can countries balance development goals with forest protection? Setting aside the issue of its practical realization, the paper concludes that forest sustainable development cannot be achieved by implementing simple technical improvements in land-use practices alone. Securing the foundations for the sustainability of the forest base will require that countries address the underlying social processes driving tropical forest loss as well.KEY WORDS: Tropical deforestation; Developing countries; Rural land-use practices; Development; Scarcity.  相似文献   
73.
ABSTRACT: A significant portion of all pollutants entering surface waters (streams, lakes, estuaries, and wetlands) derives from non-point source (NPS) pollution and, in particular, agricultural activities. The first step in restoring a water resource is to focus on the primary water quality problem in the watershed. The most appropriate NPS control measures, which include best management practices (BMPs) and landscape features, such as wetlands and riparian areas, can then be selected and positioned to minimize or mitigate the identified pollutant(s). A computer-based decision sup. port and educational software system, WATERSHEDSS (WATER, Soil, and Hydro-Environmental Decision Support System), has been developed to aid managers in defining their water quality problems and selecting appropriate NPS control measures. The three primary objectives of WATERSHEDSS are (1) to transfer water quality and land treatment information to watershed managers in order to assist them with appropriate land management/land treatment decisions; (2) to assess NPS pollution in a watershed based on user-supplied information and decisions; and (3) to evaluate, through geographical information systems-assisted modeling, the water quality effects of alternative land treatment scenarios. WATERSHEDSS is available on the World Wide Web (Web) at http://h2osparc.wq.ncsu.edu .  相似文献   
74.
ABSTRACT: To quantify the effectiveness of best management practice (BMP) implementation on runoff, sediment, and nutrient yields from a watershed, the Nomini Creek watershed and water quality monitoring project was initiated in 1985, in Westmoreland County, Virginia. The changes in nonpoint source (NPS) loadings resulting from BMPs were evaluated by comparing selected parameters from data series obtained before, during, and after periods of BMP implementation. The results indicated that the watershed-averaged curve number, sediment, and nutrient (N and P) concentrations were reduced by approximately 5, 20, and 40 percent, respectively, due to BMP implementation. The nutrient yield model developed by Frere et al. (1980) was applied to the water quality parameters from 175 storms, but it failed to adequately describe the observed phenomena. Seasonal changes in nutrient availability factors were not consistent with field conditions, nor were they significantly different in the pm- and post-BMP periods. An extended period of monitoring, with intensive BMP implementation over a larger portion of the watershed, is required to identify BMP effectiveness.  相似文献   
75.
The Thar Desert of western India is known for its rich and ancient culture system and traditions. The communities have long been part of the Thar Desert ecosystem and have evolved specific strategies to live in harmony with its hostile environment. This culture has provided several miracle plants of immense food and medicinal value to modern civilisation. The ancient rural livelihood knowledge system reflects time-tested techno-scientific knowledge with a proven track record of sustainability, especially during natural hazards like drought and famines. In addition, several of the traditional skills of local communities in arts and crafts, music and instruments have made modern man aware of the art and techniques of sustainably utilising local biological resources and preserving their biodiversity along with using waste products of the forests, without harming the desert ecosystem. Traditional cultural and socio-religious values are fast dwindling under the impact of materialistic approach, industrialisation and development. This paper endeavours to illustrate the need to assist and propagate indigenous rural livelihood systems rather than mindlessly replace or abandon them as a result of state bureaucracies.  相似文献   
76.
The over-use of agrochemicals may have adverse effects on soils along with surface and groundwater. An assessment of alternative management practices to reduce the application of agrochemicals and minimise the pollution of water resources was carried out in the vegetable agro-ecosystem in the Rattaphum Catchment. This paper details the factors that govern the volume of agrochemicals used on high intensity crops in this area, covering the choice of crop and cropping patterns, level of pest and weed infestation and the socio-economic status of farmers such as capital, size of holding and labour availability. Alternative management practices tested included (i) a reduction in the use of pesticides and chemical fertilisers; (ii) the use of bio-insecticides and bio-fertilisers; and (iii) the development of buffer zones near streams to reduce nutrient leaching into surface water systems. The results showed that when compared with bio-insecticides, synthetic insecticides were more effective in controlling major insect pests during chaisim vegetable production and were associated with higher net incomes. The high rate of application of chemical fertilisers in home gardens and commercial farms led to the accumulation of phosphorous and potassium in the top soil, with the traditional method of combining organic and chemical fertilisers producing the highest total nitrogen soil content. A fifty percent reduction in chemical fertilisers in the commercial farms produced the lowest total nitrogen soil content, without any apparent change in crop yield. The three types of tested buffers seem to be effective in reducing runoff and sediment load and were particularly efficient in lowering nutrient leaching to streams; the best results were obtained with an effective length of 2.5 m.  相似文献   
77.
Cultural taboos and their sanctionshave helped to check abuse of the environmentat least among the local people. The disregardfor these traditional checks and balancesespecially among Christians has adverselyaffected their enforcement at this time. Theenvironment and culture preservation inAwka-South were investigated. The faithfulobservance of the traditional laws in the studyarea was attributed to the fact that Awka-Southarea had remained occupied by the same peoplefor centuries. The study showed that thepreserved forests and their shrines in Nibotown have largely remained intact. In Nisetown, however, with nine shrines still inexistence, the rules have relaxed a little,mainly because they embraced modernization. Inthis town, the fringes of the forests may beused for farming but no felling of trees wouldbe allowed. The ``god' of the shrine in Obunaguvillage was much revered until the advent ofChristianity. This religion has had an erodingeffect on the taboos, which were put in placeto protect their forests and streams. Theabandonment of traditional cultural practicesis doing harm that goes beyond the abrogationof traditional cultural practices to seriousthreat to natural environmental structures. Thecultures of the different tribes in Nigerianeed to be revisited for evaluation and studiesto enable their integration into modernpractices that will make the environment moresustainable. This will be more productive thanthe unilateral introduction of programs,execution, and maintenance methods that arecompletely new, or in many cases run contraryto the cultural practices of the local peopleand tribes of Nigeria.  相似文献   
78.
ABSTRACT: This paper describes a concerted effort by the Taiwan Water Resources Bureau, the City of Taipei, and the Bureau of Fei‐tsui Reservoir Management to protect the water quality in the Fei‐tsui Reservoir.The reservoir is the major source of water supply for over two million people in the metropolitan area of Taipei. Over the years the reservoir has suffered from siltation and more recently eutrophication. The sources of the pollution are traced to the hundreds of tea gardens, rice fields and other agricultural areas in the watershed and to urban sources such as construction sites. Large amounts of nutrients enter the reservoir by way of storm water runoff during storm or typhoon events. Since 1999, various agencies have worked to initiate an effort to reduce nonpoint pollution in the Fei‐Tsui Reservoir watershed. Practices being considered include nonstructural measures such as nutrient management, and structural measures such as swales, detention basins, and wetlands, in addition to erosion and sediment control methods. A number of field tests have been completed on the performance of selected best management practices (BMPs). A strategy for implementing the BMPs at the watershed scale has been developed based on a total maximum daily load (TMDL) analysis that is reported in this paper.  相似文献   
79.
The purpose of this study is to examine the critical success factors of sustainable manufacturing practices (SMPs) in Malaysian automotive industry. The questionnaires were designed and distributed to the 50 respondents. The pilot study sample consists of 26 respondents from 50 questionnaires, with an average response rate of 52%. The results of reliability analysis show that social responsibility is critical factor influencing the direct SMPs implementation success. By implementing SMPs in Malaysian automotive industry, it can assist company to improve the quality of management. Thus, this study recommends that the future research explore the influence of SMPs on sustainable performance in Malaysian automotive industry.  相似文献   
80.
Stormwater runoff and associated pollutants from urban areas in the greater Chesapeake Bay Watershed (CBW) impair local streams and downstream ecosystems, despite urbanized land comprising only 7% of the CBW area. More recently, stormwater best management practices (BMPs) have been implemented in a low impact development (LID) manner to treat stormwater runoff closer to its source. This approach included the development of a novel BMP model to compare traditional and LID design, pioneering the use of comprehensively digitized storm sewer infrastructure and BMP design connectivity with spatial patterns in a geographic information system at the watershed scale. The goal was to compare total watershed pollutant removal efficiency in two study watersheds with differing spatial patterns of BMP design (traditional and LID), by quantifying the improved water quality benefit of LID BMP design. An estimate of uncertainty was included in the modeling framework by using ranges for BMP pollutant removal efficiencies that were based on the literature. Our model, using Monte Carlo analysis, predicted that the LID watershed removed approximately 78 kg more nitrogen, 3 kg more phosphorus, and 1,592 kg more sediment per square kilometer as compared with the traditional watershed on an annual basis. Our research provides planners a valuable model to prioritize watersheds for BMP design based on model results or in optimizing BMP selection.  相似文献   
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