Using the method of emergy analysis, we analyze the input and output of agroecological economic system, and select five indicators (net emergy yield ratio, emergy investment ratio, environmental loading ratio, emergy ...Using the method of emergy analysis, we analyze the input and output of agroecological economic system, and select five indicators (net emergy yield ratio, emergy investment ratio, environmental loading ratio, emergy sustainability index, and dominance of emergy yield system) for assessment. The results show that the emergy input-output in Wu'an City is in general on the rise; the emergy investment ratio rises constantly, but the net emergy yield ratio decreases, and the comparative advantage in the prices of agricultural products is gradually lost. At the same time, with increase in the non-renewable industrial support emergy, the environmental pressures are also mounting. In the future agricultural development, it is necessary to pay more attention to the coordination between agricultural development and ecological environment, achieving sustainable development of agriculture.展开更多
A mineral resource zone,rich in resources and energy,is intensively developed and disturbed by human activities,which causes an obvious change of landscapes.Taking Wu’an of Hebei Province,China,as a case study,this p...A mineral resource zone,rich in resources and energy,is intensively developed and disturbed by human activities,which causes an obvious change of landscapes.Taking Wu’an of Hebei Province,China,as a case study,this paper extracts landscape information of mineral resource zones through overlapping mineral resources distribution map and landscape pattern map.And then,various landscape indices are selected for analyzing the effects of grain size(30,60,90,120,150,180,210,240,270 and 300 m)on landscape patterns.Due to different kinds of landscape information transmitted by indices,the changing trends vary with the increase of grain sizes.Accordingly the landscape indices are classified into three types of effects:disturbance,continuity and sustainability,and each type of effect has its own optimal range for grain sizes.Then the optimal range of grain size on landscape patterns in mineral resource zones is gained through a comparison of the effects in various grain sizes of landscape indices.The best first domain of scale covers 30-90 m,with a suitable grain size of 30-60 m before intensive mining and a suitable grain size of 60-90 m after intensive mining.Besides,the suitable grain sizes for reflecting disturbance,continuity and sustainability before intensive mining are 30-60,30-60 and 30-90 m,respectively,however,the sizes are changed to 60-90,60-90 and 30-90 m,respectively,after intensive mining.The results are helpful for rational land use and optimal landscape allocation.展开更多
基金Supported by Supported by the Fundamental Research Funds for the Central Universities
文摘Using the method of emergy analysis, we analyze the input and output of agroecological economic system, and select five indicators (net emergy yield ratio, emergy investment ratio, environmental loading ratio, emergy sustainability index, and dominance of emergy yield system) for assessment. The results show that the emergy input-output in Wu'an City is in general on the rise; the emergy investment ratio rises constantly, but the net emergy yield ratio decreases, and the comparative advantage in the prices of agricultural products is gradually lost. At the same time, with increase in the non-renewable industrial support emergy, the environmental pressures are also mounting. In the future agricultural development, it is necessary to pay more attention to the coordination between agricultural development and ecological environment, achieving sustainable development of agriculture.
基金supported by National Natural Science Foundation of China(Grant No.41101531)Doctoral Fund of Ministry of Education of China(New Teacher Fund)(Grant No.20110022120010)Beijing Higher Education Young Elite Teacher Project(No.YETP0639).
文摘A mineral resource zone,rich in resources and energy,is intensively developed and disturbed by human activities,which causes an obvious change of landscapes.Taking Wu’an of Hebei Province,China,as a case study,this paper extracts landscape information of mineral resource zones through overlapping mineral resources distribution map and landscape pattern map.And then,various landscape indices are selected for analyzing the effects of grain size(30,60,90,120,150,180,210,240,270 and 300 m)on landscape patterns.Due to different kinds of landscape information transmitted by indices,the changing trends vary with the increase of grain sizes.Accordingly the landscape indices are classified into three types of effects:disturbance,continuity and sustainability,and each type of effect has its own optimal range for grain sizes.Then the optimal range of grain size on landscape patterns in mineral resource zones is gained through a comparison of the effects in various grain sizes of landscape indices.The best first domain of scale covers 30-90 m,with a suitable grain size of 30-60 m before intensive mining and a suitable grain size of 60-90 m after intensive mining.Besides,the suitable grain sizes for reflecting disturbance,continuity and sustainability before intensive mining are 30-60,30-60 and 30-90 m,respectively,however,the sizes are changed to 60-90,60-90 and 30-90 m,respectively,after intensive mining.The results are helpful for rational land use and optimal landscape allocation.
