Emergy analysis of paddy farming in Hunan Province, China： A new perspective on sustainable development of agriculture

The multi-functionality of paddy farming has become a hot issue recently. Paddy farming provides numerous ecosystem services that are crucial to human well-being. However, evaluation of the contribution of paddy farming to human well-being usually focus on its economic value, while its non-market services are usually ignored. Only evaluating the market profits or market relative benefits cannot reflect comprehensively the contribution of paddy farming to people＇s well-being. This will affect people＇s choices for or against paddy farming activities and people＇s opt for invest or not invest in it. A comprehensive evaluation of paddy farming can provide an important reference for the government and society to conserve the multi-functionality of paddy farming and achieve sustainable development. To this end, this paper reports a case evaluation of paddy farming in Hunan, the largest rice producing as well as rice yield province in China, and uses emergy theory to make a comprehensive evaluation for paddy farming. The emergy evaluation results of the paddy ecosystem in Hunan are as follows： in 2010, the input emergy of the paddy ecosystem in Hunan is 2.51E＋22 sej and the output emergy is 6.31E＋22sej. For the input emergy, the part from natural resources is 1.96E＋21 sej and the part from human society is 2.32E＋22sej; for the output emergy, the part from products is 2.22E＋22 sej, the part from impositive externality is 4.16E＋22 sej and the part from negative externality is –7.41E＋20 sej. Taking the non-market outputs into consideration, the gains from the human economic society＇s 1 $ input in paddy farming, emergy sustainability index（ESI） and emergy profit rate are respectively 2.73 $, 3.53 and 151.31%. If the evaluation leave out the non-market output, the three indexes are only 0.96 $,1.24 and 30.67%. The research results show that non-market services of paddy farming contribute significantly to human well-being. Therefore, in order to protect the multi-functionality of paddy farming and achieve the sustainable management,the government should take reasonable measures and make incentive plans.

Sustainable Utilization of Agricultural Land in Chengdu Metropolitan Area Based on Emergy Analysis

[Objectives]This study aimed to analyze the sustainable use of agricultural land in the Chengdu metropolitan area from 2006 to 2016.[Methods]Using Odum's emergy theory,an index system was constructed to evaluate the sustainable use of agricultural land,including total emergy input-output ratio,industrial emergy input-output ratio,environmental load index and sustainable use index of agricultural land based on emergy,to reflect the sustainable use of agricultural land in the Chengdu metropolitan area.The data base was a unified standard that was converted from various types of energy stored and flowing in the agricultural land system of the Chengdu metropolitan area,that is,emergy.[Results]From 2006 to 2016,the total emergy input-output ratio of agricultural land in the metropolitan area fluctuated and decreased,lower than the national average.The industrial emergy input-output ratio was generally in a fluctuating downward trend.The environmental load index of agricultural land in the metropolitan area was lower than the national average.However,it has been on the rise since 2012.During the corresponding period,the sustainable use index of the region also showed a downward trend.[Conclusions]The utilization rate of emergy in this area was low.The dependence of industrial emergy input-output ratio on industrial subsidiary energy and the degree of agricultural mechanization are constantly improving.The environmental resources in this area still have room for accommodation and have not been fully utilized.The sustainable use of agricultural land has been declining.

Simulation Technology of Environmental Impacts by Zero-energy Residential Buildings Based on Emergy Analysis Method

This paper presents a simulation technology of environmental impact for the building. By emergy analysis method,emergy costs of building( or construction engineering) can be calculated in the life cycle. It includes the engineering cost, environmental cost and social cost of building. Through integrating GIS technology with multi-agent technology,life cycle substance and energy metabolism of building( construction engineering) can be simulated and their environmental influence can be dynamically displayed. Based on the case study of entries works‘Sunny Inside'by Xiamen University in 2013 China International Solar Decathlon Competition,we discovered the changing pattern of surrounding environmental impact from waste streams of the zero-energy building and ordinary construction. The simulation results verified and showed the Odum principles of maximum power. This paper provides a new research perspective and integration approach for the environmental impact assessment in building and construction engineering. The result will help decision-making in design and construction engineering scheme.

Emergy Analysis of the Agricultural Eco-economic System in Dongting Lake Area of Hunan Province

[ Objective] The reseamh aimed to discuss eco-efficiency of the agro-ecosystem in Dongting Lake area of Hunan. [ Method] By referring to emergy reseamh method, emergy structure, function and efficiency of the system were analyzed according to emergy input -output data of the system in 2009. [ Result] The system had developed economy, and mechanization and modernization degrees were higher. Emergy output of the system was unbalanced, and market pricing of the agricultural product was significantly lower, especially farming product. Seen from sustainable development index and environmental loading ratio of the system, the system was full of vitality and development potential. The pressure of natural resources and environment was not very great, but the system accommodated too many populations. [ Conclusion] Basic direction of the agricultur- al policy in the zone was further shortening industrial and agricultural price scissors, continuing to implement price protection of the farming product, adjusting agricultural and product structures and transferring surplus labor.

Emergy Analysis of Sustainability of Eco-economic System in Sichuan's Baisha River Valley

Using emergy analysis method,I conduct quantitative analysis of social,economic and natural systems in Sichuan's Baisha River valley during the period 2002-2006,through the establishment of indicators.I compare the emergy of Baisha River valley,with that of Xinjiang's Manas River valley and Sichuan Province,and evaluate the sustainable development conditions in Baisha River valley,in order to provide corresponding reference for the development and utilization of Baisha River valley in the future.The results show that from the perspective of emergy input of economic system,Baisha River valley is a typical ecological and economic zone with rich resources to be developed;in terms of the development of natural conditions and utilization of ecological resources,the resource utilization intensity of Baisha River valley is weak and the environmental loading ratio there is low,thus the level of emergy yield needs to be improved;the system of Baisha River valley has enormous capacity for sustainable development and good potential for development.

EMERGY analysis for sustainability evaluation of the Baiyangdian wetland ecosystem in China

t This study presents a quantitative and ecological benefit evaluation of the Baiyangdian wetland in China between the years 2000 and 2006.Methods of EMERGY analysis were applied to illustrate the wetland ecosystem,to evaluate the economic and environmental inputs and consequent yields,and to assess the sustainability of the Baiyangdian wetland.The indicators for the integrated ecological and economic system,such as EMERGY yield ratio(EYR)(7.51),EMERGY investment ratio(EIR)(4.52),environmental loading ratio(ELR)(2.92),EMERGY exchange ratio(0.41),and EMERGY sustainable indicator(ESI)(2.57)were calculated,compared,analyzed,and discussed.The non-renewable investment in Baiyangdian was greater than renewable investment,leading to the unsustainable development of the system.High EYR indicated that the Baiyangdian integrated system had created huge profits for its people,while ELR and ESI revealed that human behavior has been a heavy burden on the environment,and countermeasures should be taken by the Chinese government to relieve and resolve these problems.Potential management methods were also proposed in this paper.

A new approach to natural capital sustainable development

The three-dimension(3D) ecological footprint makes the analysis of the relationships between the demand and supply of natural capital more credible by importing footprint depth and footprint size.This article used China's regions as the object to analyze the high-level sustainability of the natural capital from the view of "ecology-efficiency-fairness" multidimensional framework.Research showed that China's ecological footprint has risen while bio-capacity per capita has descended in recent 20 years.This paper also discusses the spatial distribution of China's natural capital ecological sustainability,efficiency sustainability and fairness sustainability.Finally,it builds multi-criteria evaluation(MCE) models to get multidimensional sustainability framework taking ecological sustainability,efficiency sustainability,and fairness sustainability into consideration.

Evaluation Techniques of the Loss of Marine Ecosystem Services Caused by Sea Reclamation Project Based on Three Methods

Based on the effect of marine environment caused by sea reclamation and Technical Directives for Marine Ecological Capital Assessment(GB/T 28058-2011), the indexes of the loss of coastal ecosystem services led by sea reclamation were built. The lost value of sea reclamation was calculated using three methods, namely, economic evaluation, emergy analysis and biodiversity experiential formula. The three methods were applied in the new sea reclamation in Taxia, Fuding City, Fujian Province, and the total ecosystem lost value was 6.720 million CNY/year, 8.092 million CNY/year, and 1.333 million CNY/year, respectively. Compared with other relevant researches, this paper analyzed feasibility and applicability of the three methods, so as to include project external cost into the project economic profi t and loss analysis in the evaluation of environmental infl uence, and to provide technical support for the sustainable economic development of coastal zones.