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861.
Walter T. Sittner 《Journal of the American Water Resources Association》1973,9(4):655-659
The National Weather Service is nearing the conclusion of a five year period of transition from index type catchment modelling to the use of conceptual hydrologic models. The decision to make this technological change was based on an extensive research project in which various catchment models were tested in a wide variety of basins and their strong and weak points ascertained. This project is described. Some of the problems involved in the changeover, which are discussed, are practical parameter optimization methods, computer requirements for the more complex technology, data requirements, fitting of the catchment model to major river systems, training of personnel and staffing problems. 相似文献
862.
An evaluation of different hydrogen production technologies based on renewable raw materials and/or renewable energy is presented. The evaluation comprises alkaline electrolysis, steam reforming of both biogas and gasification gas, the coupled dark and photo fermentation as well as the coupled dark and biogas fermentation. Each technology is investigated with different plant layouts and/or different raw materials. All examined technologies are designed to produce hydrogen in a quality suitable for the use in mobile fuel cells. The presented evaluation is based on the hydrogen production efficiency and the energy efficiency of the processes. 相似文献
863.
Environmental cross-compliance mitigates nitrogen and phosphorus pollution from Swiss agriculture 总被引:1,自引:0,他引:1
In 1993 the Swiss agricultural policy was revised with – amongst other goals – the objective of improving the environmental performance of agriculture. A voluntary agri-environmental scheme to promote integrated production (IP) was introduced. In 1999 the IP standards were integrated in cross compliance requirements and termed Proof of Ecological Performance (PEP). We evaluated the effectiveness of this policy in terms of reducing diffuse nitrogen (N) and phosphorus (P) pollution of ground and surface water. We combined monitoring schemes covering the reference period from before the introduction of IP/PEP (1990–1992) with the evaluation of cause/effect relationships in selected case-study areas. The evaluation showed an overall reduction of diffuse N and P pollution from agriculture even though some goals were not reached. Nitrate leaching declined, but only a 3–4 mg L−1 reduction was observed rather than the intended decrease of 5 mg L−1. The P pollution of surface waters from agriculture decreased by only 10–30% instead of 50%. The intended reduction of the nitrogen surplus of Swiss agriculture by 33% was not attained, but the P surplus of Swiss agriculture was more than halved. IP/PEP practices that improved N and P management included reduced N and P fertiliser inputs and pig and poultry feedstuffs with reduced N and P contents, both of which are a consequence of the requirement of equilibrated farm nutrient balances, as well as increased use of cover cropping and of conservation tillage systems. 相似文献
864.
Environmental Chemistry Letters - Microplastics are recently discovered contaminants, yet knowledge on their sources and analysis is limited. For instance, paint microplastics are poorly known... 相似文献
865.
Rodrigo Goyannes Gusmão Caiado Osvaldo Luiz Gonçalves Quelhas Daniel Luiz Mattos Nascimento Rosley Anholon Walter Leal Filho 《国际发展与全球生态学杂志》2018,25(4):312-326
In recent years, sustainability issues are gaining greater prominence among organizations and their stakeholders around the world. This paper aims to verify the sustainability performance of Brazilian organizations in performance measures and to propose sustainable guidelines with the intention of directing future efforts to the transition to sustainable development. The research utilized a triangulated approach by collecting qualitative and quantitative data acquired through multiple collection methods of a theoretical literature review, documentary analysis of corporate reports, questionnaire survey and semi-structured interviews with industry professionals and academic researchers. The results show that internal organizational factors are the main inductors of the sustainable environment in organizations, and sustainability must be tied to strategic planning, starting from upper management to lower levels. It is essential to use sustainable performance measurement systems in order to respond to external and internal levers and serve as benchmarking for future corporate operations and strategies. In addition, it is the responsibility of organizations to focus their efforts on environmental protection, reduction of energy, corporate reputation, quality management, customer satisfaction and investor relations, as they are considered to be more important and have a relationship of dependence on organizational sustainability. The findings will be of value to professionals and academics who want to start measuring and for continuously improving the sustainability performance of their organizations according to the technical, economic, environmental, social and governance dimensions. This research work also helps to understand the perceptions and expectations of stakeholders. 相似文献
866.
Walter Leal Filho Ulisses Azeiteiro Fátima Alves Paul Pace Mark Mifsud Luciana Brandli 《国际发展与全球生态学杂志》2018,25(2):131-142
The United Nations Sustainable Development Goals (UN SDGs) contain a set of 17 measures to foster sustainable development across many areas. It offers a good opportunity to reinvigorate sustainable development research for two main reasons. First, it comprises many areas of SD research, which have become mainstream thanks to the UN SDGs. Second, the fact that the UN and its member countries have committed to attaining SDGs by 2030 has added a sense of urgency to the need to perform quality research on SD on the one hand, and reiterates the need to use the results of this research on the other. Even though the basic concept of sustainability goes back many centuries, it has only recently appeared on the international political agenda. This is partly due to an awakening of the fact that the human ecological pressure on the planet is still much larger than what nature can renew or compensate for. Based on this state of affairs, this paper presents an outline of the process leading to the agreement on the UN SDGs, and looks at some of the ecological aspects as a result of continued pressure of human activities on natural resources. Furthermore, a set of research needs is proposed – also based holistically on updated research trends – discussing the degree of urgency of some measures and explaining why the UN SDGs need to be accorded greater priority in international sustainable development research efforts. 相似文献