In the past thirty years, various hydropower projects, some with a dam height of over 300 m, have been planned and constructed within China. It is inevitable that these will have sizable effects on the environment, an...In the past thirty years, various hydropower projects, some with a dam height of over 300 m, have been planned and constructed within China. It is inevitable that these will have sizable effects on the environment, and it is crucial therefore to reasonably evaluate and control adverse effects. In this paper, the transformities of various items for hydropower projects were systematically analyzed, and an emergy footprint model for the projects was developed based on ecological footprint analyses and emergy theory, so that it can quantitatively evaluate the effects on the environment, both positive and negative, resulting from the whole process of planning, constructing and operating the projects. As an example, the effects of a large-scale hydropower project, the 'LP project', were investigated. The results showed that the hydropower projects have strong positive effects on the environment and can even in the short term balance the emergy footprint appropriation resulting from the construction and operation of the hydropower projects. Finally, suggestions were presented for the design of hydropower projects.展开更多
This article uses the conventional ecological footprint method and its improved model of ecological footprint to analyze the state of the sustainable development of Wuhan City in 2009, the results show that the per ca...This article uses the conventional ecological footprint method and its improved model of ecological footprint to analyze the state of the sustainable development of Wuhan City in 2009, the results show that the per capita ecological deficit calculated by the method of emergy ecological footprint is 3.8629 hm2, and the per capita ecological deficit calculated by the method of conventional ecological footprint is 2.0169 hm2. The results obtained by the two methods respectively show that current development of Wuhan is unsustainable. The emergy ecological footprint method introduces the energy flow to reflect the relationship between human resource demand and supply of nature to human and adopts parameters—emergy conversion rate and energy density to calculate the ecological carrying capacity data which is more accurate.展开更多
Feeding a large and growing population with scientifically sustainable food production is a major challenge globally,especially in smallholder-based agricultural production.Scientists have conducted a considerable the...Feeding a large and growing population with scientifically sustainable food production is a major challenge globally,especially in smallholder-based agricultural production.Scientists have conducted a considerable theoretical research and technological innovation to synergistically achieve increased food production and reduced environmental impact.However,the potential and feasibility of synergistic smallholder-led agricultural production to achieve increased food production and environmental friendliness is not yet clear.Exploring the potential and feasibility of smallholders to synergistically achieve these two goals,this research collected survey data from 162 farmers implementing standard farming practices and 112 farmers engaged in Science and Technology Backyard(STB)in Quzhou County,Hebei Province,China.Grain yield,nitrogen use efficiency(NUE),greenhouse gas emissions(GHG),and emergy ecological footprint(EEF)of the wheat-maize cropping system dominated by smallholders were analyzed.The results showed smallholders in the STB group improved wheat and maize yields by about 13%and NUE by 20%,respectively.Also,a reduction of 23%in GHG emissions and 52%in EEF were simultaneously achieved in the wheat-maize cropping system.Compared with standard farming practices,75 kg·ha−1 nitrogen-based fertilizer was saved in the STB farmers.In summary,this study shifts the main perspective of research from scientists to smallholder,and uses a combination of greenhouse gas emission calculations,EEF and material flow analyses to demonstrate from multiple perspectives that agricultural systems under the leadership of smallholders can synergistically achieve high crop yields and low resource use and environmental impacts.The results of this study also show that the smallholder-led scientist-farmer collaborative model established by STB can fully exploit the initiative and potential,and that this collaborative model can be a successful strategy for smallholders as operators to achieve food security at low environmental impacts.The results of this study can provide useful evidence for a sustainable shift toward more sustainable agricultural production systems.展开更多
基金supported by the Ministry of Education Foundation in China (Grant No. 108177)
文摘In the past thirty years, various hydropower projects, some with a dam height of over 300 m, have been planned and constructed within China. It is inevitable that these will have sizable effects on the environment, and it is crucial therefore to reasonably evaluate and control adverse effects. In this paper, the transformities of various items for hydropower projects were systematically analyzed, and an emergy footprint model for the projects was developed based on ecological footprint analyses and emergy theory, so that it can quantitatively evaluate the effects on the environment, both positive and negative, resulting from the whole process of planning, constructing and operating the projects. As an example, the effects of a large-scale hydropower project, the 'LP project', were investigated. The results showed that the hydropower projects have strong positive effects on the environment and can even in the short term balance the emergy footprint appropriation resulting from the construction and operation of the hydropower projects. Finally, suggestions were presented for the design of hydropower projects.
文摘This article uses the conventional ecological footprint method and its improved model of ecological footprint to analyze the state of the sustainable development of Wuhan City in 2009, the results show that the per capita ecological deficit calculated by the method of emergy ecological footprint is 3.8629 hm2, and the per capita ecological deficit calculated by the method of conventional ecological footprint is 2.0169 hm2. The results obtained by the two methods respectively show that current development of Wuhan is unsustainable. The emergy ecological footprint method introduces the energy flow to reflect the relationship between human resource demand and supply of nature to human and adopts parameters—emergy conversion rate and energy density to calculate the ecological carrying capacity data which is more accurate.
基金supported by National Key R&D Program of China(2017YFD0200200/0200206)National Natural Science Foundation of China(32172675,41701614)+1 种基金Science and Technology Talents and Platform Program of Yunnan Province(2019IC026)China Scholarship Council(201913043)。
文摘Feeding a large and growing population with scientifically sustainable food production is a major challenge globally,especially in smallholder-based agricultural production.Scientists have conducted a considerable theoretical research and technological innovation to synergistically achieve increased food production and reduced environmental impact.However,the potential and feasibility of synergistic smallholder-led agricultural production to achieve increased food production and environmental friendliness is not yet clear.Exploring the potential and feasibility of smallholders to synergistically achieve these two goals,this research collected survey data from 162 farmers implementing standard farming practices and 112 farmers engaged in Science and Technology Backyard(STB)in Quzhou County,Hebei Province,China.Grain yield,nitrogen use efficiency(NUE),greenhouse gas emissions(GHG),and emergy ecological footprint(EEF)of the wheat-maize cropping system dominated by smallholders were analyzed.The results showed smallholders in the STB group improved wheat and maize yields by about 13%and NUE by 20%,respectively.Also,a reduction of 23%in GHG emissions and 52%in EEF were simultaneously achieved in the wheat-maize cropping system.Compared with standard farming practices,75 kg·ha−1 nitrogen-based fertilizer was saved in the STB farmers.In summary,this study shifts the main perspective of research from scientists to smallholder,and uses a combination of greenhouse gas emission calculations,EEF and material flow analyses to demonstrate from multiple perspectives that agricultural systems under the leadership of smallholders can synergistically achieve high crop yields and low resource use and environmental impacts.The results of this study also show that the smallholder-led scientist-farmer collaborative model established by STB can fully exploit the initiative and potential,and that this collaborative model can be a successful strategy for smallholders as operators to achieve food security at low environmental impacts.The results of this study can provide useful evidence for a sustainable shift toward more sustainable agricultural production systems.
