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1.
选取吉林省抚松县为研究区域,采用能值分析方法,从生态安全、经济发展、社会接受方面建立评价指标体系,对吉林省抚松县生态经济系统进行定量和定性评价。研究结果表明:①2005--2009年抚松县生态经济系统能值投入量和能值产出量均呈增加态势,能值投入以本地资源为主,工业产值迅速增加(以林产品为主),而农产品产值持续减少。②抚松县经济发展水平在全国、全省范围内均属于较低水平,工业发展效率很低,居民生活质量不高。③生态环境压力逐年增大,主要原因是自然资源的大规模开发,但是与其他发达地区、我国西部地区相比,抚松县在生态环境承载力方面仍具有相对优势。据此,提出了通过大力发展旅游产业、绿色食品、林产品的深加工等增强系统开放性,深入挖掘优势资源的高价值形态,以达到山区县域经济的可持续发展。  相似文献   

2.
Energy Systems Theory (EST) provides a framework for understanding and interpreting sustainability. EST implies that "what is sustainable" for a system at any given level of organization is determined by the cycles of change originating in the next larger system and within the system of concern. The pulsing paradigm explains the ubiquitous cycles of change that apparently govern ecosystems, rather than succession to a steady state that is then sustainable. Therefore, to make robust decisions among environmental policies and alternatives, decision-makers need to know where their system resides in the cycles of change that govern it. This theory was examined by performing an emergy evaluation of the sustainability of a regional system, the San Luis Basin (SLB), CO. By 1980, the SLB contained a climax stage agricultural system with well-developed crop and livestock production along with food and animal waste processing. The SLB is also a hinterland in that it exports raw materials and primary products (exploitation stage) to more developed areas. Emergy indices calculated for the SLB from 1995 to 2005 revealed changes in the relative sustainability of the system over this time. The sustainability of the region as indicated by the renewable emergy used as a percent of total use declined 4%, whereas, the renewable carrying capacity declined 6% over this time. The Emergy Sustainability Index (ESI) showed the largest decline (27%) in the sustainability of the region. The total emergy used by the SLB, a measure of system well-being, was fairly stable (CV?=?0.05). In 1997, using renewable emergy alone, the SLB could support 50.7% of its population at the current standard of living, while under similar conditions the U.S. could support only 4.8% of its population. In contrast to other indices of sustainability, a new index, the Emergy Sustainable Use Index (ESUI), which considers the benefits gained by the larger system compared to the potential for local environmental damage, increased 34% over the period.  相似文献   

3.
China is the largest rice producing and consuming country in the world, but rice production has given way to the production of vegetables during the past twenty years. The government has been trying to stop this land-use conversion and increase the area in rice-vegetable rotation. Important questions that must be answered to determine what strategy is best for society are, “What is the reason behind this conversion?”; “Which system is more productive and which is more sustainable?”; and “How can economic policy be used to adjust the pattern of farmland use to attain sustainable development?” To answer these questions, a combined evaluation of these agricultural production systems was done using emergy, energy and economic methods. An economic analysis clearly showed that the reason for this conversion was simply that the economic output/input ratio and the benefit density of the vegetable production system were greater than that of rice. However, both energy and emergy evaluations showed that long-term rice was the best choice for sustainable development, followed by rotation systems. The current price of rice is lower than the em-value of rice produced from the long-term rice system, but higher than that of rice produced from the rotation system. Scenario analysis showed that if the government increases the price of rice to the em-value of rice produced from the long-term rice system, US$0.4/kg, and takes the value of soil organic matter into account, the economic output/input ratios of both the rice and rotation systems will be higher than that of the vegetable system. The three methods, energy, emergy and economics, are different but complementary, each revealing a different aspect of the same system. Their combined use shows not only the reasons behind a system’s current state or condition, but also the way to adjust these systems to move toward more sustainable states.  相似文献   

4.
基于能值分析的苏州市城市生态系统可持续发展评估   总被引:1,自引:0,他引:1  
周婧  王远  陈洁 《四川环境》2010,29(4):72-77
本文利用能值分析的方法,分析了苏州城市生态系统的各种生态流,并建立了苏州城市生态系统可持续发展能值评价指标体系,评估其可持续发展程度,并对其能值指标的发展进行了预测。研究结果显示,2007年苏州市系统利用总能值达到616.71×1021sej,能值自给率仅为35.5%,环境负载率达到61.67。与其他国家和地区能值指标对比得出,苏州市是一个高度外向型生态经济系统,其系统的发展高度依赖于外界资源的输入,面对现在不稳定的世界经济发展和外部环境,苏州市必须加大系统自身的供给能力,提高系统自身的稳定性;发展循环经济,降低系统环境负载率;加强高科技和人才投入,提高系统可持续发展潜力。  相似文献   

5.
Sustainable water use is seriously compromised in the North China Plain (NCP) due to the huge water requirements of agriculture, the largest use of water resources. An integrated approach which combines the ecosystem model with emergy analysis is presented to determine the optimum quantity of irrigation for sustainable development in irrigated cropping systems. Since the traditional emergy method pays little attention to the dynamic interaction among components of the ecological system and dynamic emergy accounting is in its infancy, it is hard to evaluate the cropping system in hypothetical situations or in response to specific changes. In order to solve this problem, an ecosystem model (Vegetation Interface Processes (VIP) model) is introduced for emergy analysis to describe the production processes. Some raw data, collected by investigating or observing in conventional emergy analysis, may be calculated by the VIP model in the new approach. To demonstrate the advantage of this new approach, we use it to assess the wheat-maize rotation cropping system at different irrigation levels and derive the optimum quantity of irrigation according to the index of ecosystem sustainable development in NCP. The results show, the optimum quantity of irrigation in this region should be 240–330 mm per year in the wheat system and no irrigation in the maize system, because with this quantity of irrigation the rotation crop system reveals: best efficiency in energy transformation (transformity = 6.05E + 4 sej/J); highest sustainability (renewability = 25%); lowest environmental impact (environmental loading ratio = 3.5) and the greatest sustainability index (Emergy Sustainability Index = 0.47) compared with the system in other irrigation amounts. This study demonstrates that application of the new approach is broader than the conventional emergy analysis and the new approach is helpful in optimizing resources allocation, resource-savings and maintaining agricultural sustainability.  相似文献   

6.
Sustainable development of coastal zones must balance economic development that encourages human visitation from a larger population with desires that differ from the local residents with the need to maintain opportunities for the local resident society and conserve ecological capital, which may serve as the basis for residents.We present a case study in which the sustainability level of a coastal zone (Riviera del Beigua), located along the Ligurian coast of north-western Italy, was assessed through the lens of systems ecology using emergy synthesis to integrate across economic, social and environmental sub-systems.Our purposes were (1) to quantify the environmental sustainability level of this coastal zone, (2) to evaluate the role of tourism in affecting the economy, society and environment, and (3) to compare emergy synthesis to Butler's Tourism Area Life Cycle model (TALC). Results showed that 81% of the total emergy consumption in the coastal zone was derived from external sources, indicating that this tourist-heavy community was not sustainable. Tourism, as the dominant economic sub-system, consumed 42% of the total emergy budget, while local residents used the remaining 58%. The progressive stages of the TALC model were found to parallel the dynamic changes in the ratio of external emergy inputs to local emergy inputs, suggesting that emergy synthesis could be a useful tool for detecting a tourist region's TALC stage. Use of such a quantitative tool could expedite sustainability assessment to allow administrative managers to understand the complex relationship between a region's economy, environment and resident society so sound policies can be developed to improve overall sustainability.  相似文献   

7.
Emergy and economic methods were used to evaluate and compare three fish production models, i.e., cage fish farming system, pond intensive fish rearing system and semi-natural extensive pond fish rearing system, in Nansi Lake area in China in the year 2007. The goal of this study was to understand the benefits and driving forces of selected fish production models from ecological and economic points of view. The study considered input structure, production efficiency, environmental impacts, economic viability and sustainability. Results show that the main difference among the three production systems was the emergy cost for fish feed associated with their feeding system, i.e., feeding on natural biomass such as plankton and grass or on commercial feedstock. As indicated by EYR, ELR and ESI, it can be clearly shown that the intensive production model with commercial feed is not a sustainable pattern. However, the point is that more environmentally sound patterns do not seem able to provide a competitive net profit in the short run. The intensive pond fish farming system had a net profit of 2.57E+03 $/ha, much higher than 1.27E+03 $/ha for cage fish farming system and slightly higher than 2.37E+03 $/ha for semi-natural fish farming system. With regard to the drivers of local farmer’s decisions, the accessibility of land for the required use and investment ability determine the farmer’s choice of the production model and the scale of operation, while other factors seem to have little effect. Theoretically, the development of environmentally sustainable production patterns, namely water and land conservation measures, greener feed as well as low waste systems is urgently needed, to keep production activities within the carrying capacity of ecosystems. Coupled emergy and economic analyses can provide better insight into the environmental and economic benefits of fish production systems and help solve the problems encountered during policy making.  相似文献   

8.
The environmental sustainability of a fish farm rearing process was examined by means of emergy analysis. Many emergy analyses integrate data for a whole year smoothing short term variations and sometimes losing meaningful information (aliasing). For this reason we developed a model for an instantaneous emergy evaluation in an aquacultural system so that transformities, efficiency and effort spent at each moment during the fish rearing activity could be calculated. By means of the model and dynamic emergy calculations it is possible to recognize step by step the importance of the various emergy contributions and verify where and when to modify the system to move toward optimum production of a sustainable product. By the application of the model we confirmed that the emergy trends in a fish farm installation follow wide oscillations during a year due to variations in both internal and external emergy contributions. Among the fluxes considered, those due to the introduction of fingerlings represented the highest contributions to the total emergy budget. Thus, to improve the sustainability of the analyzed system the amount, frequency and timing of these fluxes must be carefully considered. For this purpose, a comparison between two different fry introduction schedules was performed to evaluate differences in the efficiency of the rearing process.  相似文献   

9.
基于能值理论,结合生态足迹方法,构建能值生态赤字/盈余、渔业足迹强度(D)、社会发展压力指数(I)和经济协调指数(Q)参数评价海岛可持续性,选取典型海岛城市浙江省舟山市作为案例研究。结果显示:2003—2017年舟山能值足迹、能值承载力均呈上升趋势;人均能值生态足迹共增加15.78 hm2,增幅为63.26%;人均能值承载力增加5.20×102 hm2,增幅为82.86%;其中,化石能源用地能值足迹增加最多,社会经济承载力增加最多,而自然承载力却有所下降。能值生态赤字/盈余和经济协调指数不能完全反映区域可持续性,区域渔业足迹强度的不断增加表明当前的渔业经济模式不满足可持续发展要求,社会发展压力指数增大也进一步表明舟山的发展状况偏离了可持续性的轨道。  相似文献   

10.
本文利用农业生产力模型对内江市的农业生产力进行了数值模拟实验。结果表明内江市农业生产的前景十分广阔,不同耕作制度的农业产值排序为稻-稻-油>稻-油>稻-麦>玉一薯一油>玉一薯一麦>稻。  相似文献   

11.
Emergy evaluation perspectives of a multipurpose dam proposal in Korea   总被引:1,自引:0,他引:1  
The 'emergy' concept was used to evaluate the economy of Korea and the contributions of a multipurpose dam proposal to the real wealth of the Korean economy. Emergy is defined as the available energy of one kind previously used up directly and indirectly to make a product or service. The indices for Korea calculated from the emergy evaluation were close to those of developed countries. Even though its monetary balance of payments was negative in 1997, the economy of Korea showed positive balance in trade when exports and imports were expressed in emergy. The emergy evaluation showed that the Korean economy places a large stress on its environment. Water supply and generation of electricity were the most important contributions of the proposed dam in terms of emergy; 46.5 and 45.1% of the total benefit, respectively. Flood control contributed 8.4% of the total benefit. Major costs associated with the proposed dam were from sediments (33.2% of the total cost), construction services (22.8%), and social disruption of the region (21.6%). In terms of emergy, the ratio of benefits to costs of the proposed dam was 2.78 if sediments are not included, and 1.86 if sediments are included, which result in more benefits than costs in both cases. The benefit to cost ratio of the dam was larger than that of the current system (1.42) without the dam whether sediments are included in the total cost or not. The environmental stress of the proposed dam was considerably lower than that of the Korean economy, but the dam might increase stress on local environment.  相似文献   

12.
Pollution of water resources by phosphorus (P) is a critical issue in regions with agricultural and urban development. In this study, we estimated P inputs from agricultural and urban sources in 24 catchments draining to the Central Valley in California and compared them with measured river P export to investigate hydrologic and anthropogenic factors affecting regional P retention and export. Using spatially explicit information on fertilizer use, livestock population, agricultural production, and human population, we calculated that net surface balances for anthropogenic P ranged from -12 to 648 kg P km yr in the early 2000s. Inorganic P fertilizer and manure P comprised the largest fraction of total input for all but two catchments. From 2000 to 2003, a median of 7% (range, -287 to 88%) of net annual anthropogenic P input was exported as total P (TP). Yields (kg P km yr) of dissolved inorganic P (DIP), dissolved organic P, particulate P, and TP were not significantly related to catchment-level, per area anthropogenic P input. However, there were significant relationships between mean annual P concentrations and P input from inorganic fertilizers and manure due to the concentration of agricultural land near catchment mouths and regional variation in runoff. Catchment-level P fertilizer and manure inputs explained 4 to 23% more variance in mean annual DIP and TP concentrations than percent of catchment area in agriculture. This study suggests that spatially explicit estimates of anthropogenic P input can help identify sources of multiple forms of P exported in rivers at management-relevant spatial scales.  相似文献   

13.
由于社会和经济因素的要求,当今的建筑生命周期要最大程度地完成圆形的循环过程,即重新使用拆建物料制造新产品。循环经济的大背景下,承建商通过坚实的理论基础,采用分层次的方法来进行建筑废弃物的管理。文中总结了两种方法的优点和缺点,进行了混合回收与源头分离两种方法的比较研究。最值得注意的是两个不同的意向方案:绿色星球计划和ICC-ESSAVETM方案。突出的可持续认证和设计方案及绿色星球计划侧重的能源效率模型时常被繁重调试系统的LEED所青睐。一旦被国际编码理事会所批准,这些文件可以在LEED的评分系统下或绿色星球计划中,帮助其寻找资格评分。文章最后分析了建筑废弃物的回收流程,并得出结论:高达95%的建筑和拆迁建筑废弃物都可以回收;回收相比垃圾填埋更节省资金;源头分离较混合回收需要更多的管理和劳动力,但能获得更大的经济利益;承建商应该组织和管理现场的回收工作。  相似文献   

14.
Agricultural drainage and wetland management in Ontario   总被引:2,自引:0,他引:2  
Land drainage is recognized as an integral part of agricultural activity throughout the world. However, the increase in agricultural production has resulted in the loss of wetland functions and values. Therefore, wetland management and agricultural drainage illustrate the conflict between economic development and natural values. This research assesses the approval process for agricultural land drainage in Ontario, Canada, to determine how the benefits of increased agricultural production are balanced against the loss of wetland values. A permit review of drainage applications was conducted from 1978 to 1997 in Zorra Township, Ontario, Canada. Data collection also included the document reviews, interviews with government agencies and wetland evaluation files. The selected criteria include efficiency, equity, consistency and adequacy. The results indicate that while the process is efficient, fundamental problems remain with the bargaining process.  相似文献   

15.
ABSTRACT: Dramatic changes in Utah's economy caused by urbanization, large scale energy developments, and other influences will significantly reorient water use patterns. Thus, state water management policies and programs which have evolved over many years should be reevaluated. Several factors have influenced Utah water project financing policy. Among these have been: 1) the prominence of agriculture in the settlement of Utah and the century following, 2) dry cycles and periodic severe droughts, 3) recurring periods of economic depression, and 4) allocation of Colorado River water among the basin states and Mexico, Three revolving funds have been established. The Revolving Construction Fund, created in 1947, provides money for irrigation projects; the Cities Water Loan Fund, created in 1975, provides money to communities for developing culinary systems and improving quality to meet the demands of exploding population growth; and the Water Resources Conservation and Development Fund, created in 1978, provides money for large scale multipurpose water projects costing $1 million or more. The justification for these financing programs seems to be a mixture of rectifying market imperfections and income redistribution. However, trends in the agricultural sector and the multipurpose nature of large scale projects now being funded suggest that earlier justifications may no longer be valid. Rigorous project evaluation procedures, lacking in the past, should be adopted.  相似文献   

16.
This study aimed to analyze the ecological, socio-economic and policy implications of land-use diversity in a traditional village landscape (900–1,000 m amsl.) in the Garhwal region of Indian Himalaya. The village landscape was differentiated into three major land-use types viz., forests, settled agriculture and shifting agriculture. Settled agriculture was further differentiated into four agroecosystem types viz., homegarden system (HGS), rainfed agroforestry system (RAS), rainfed crop system (RCS) and irrigated crop system (ICS), and shifting agriculture system (SAS) was differentiated into different stages of a 4-year long cropping phase and a 7-year long fallow phase, and forests into Community Forests (CF) and Reserve Forests (RF). HGS is the most productive agroecosystem, with soil organic carbon and nutrient concentrations significantly higher than all other forest/agricultural land-uses. Farmers capitalize upon crop diversity to cope with the risks and uncertainties of a monsoon climate and spatial variability in ecological factors influencing productivity. The SAS, a land-use adopted as a means of acquiring inheritable rights over larger land holdings provided in the policies during the 1890s, is less efficient in terms of land productivity than the traditional RAS and HGS but is maintained for its high labour productivity coupled with availability of high-quality fuelwood from fallow vegetation. Dominance of fodder trees in the RAS seems to derive from policies causing shortage of fodder available from forests. Cultural norms have favoured equity by allowing hiring of labour only from within the village community and income from non-timber forest products only to the weaker section of the society. Conversion of rainfed to irrigated cropping, a change facilitated by the government, improves agricultural productivity but also increases pressure on forests due to higher rates of farmyard manure input to the irrigated crops. Existing forest management systems are not effective in maintenance of a large basal area in forests together with high levels of species richness, soil fertility and resistance to invasive alien species Lantana camara. Farmers have to spend huge amount of labour and time in producing manure, managing livestock and other subsidiary farm activities. Interlinkages among agriculture, forests and rural economy suggest a need of replacing the present policies of treating agricultural development, forest conservation and economic development as independent sectors by an integrated sustainable development policy. The policy should promote technological and institutional innovations enabling parallel improvements in agricultural productivity and functions of forest ecosystems.  相似文献   

17.
A myriad of factors, both economic and political, influenced the voting by members of the United States Congress on the 1978 National Energy Act. Determinant factors considered in our analysis included the percentage of residents in the Congressman's district residing in the central city or on farms; the percentage of residents who belong to labor unions; the average level of education of the residents; oil, coal, and natural gas production in the state relative to total domestic production. The results, determined by means of logit analysis, indicate that the impact on low-income energy consumers, the effect on overall employment, the impact on farmers, and the benefits to energy interests, as well as ideology and the subjective perception that the need exists to do something about the energy situation in the United States, were all important explanatory factors.The author is an economist with the United States Department of Energy. The views expressed are those of the author and do not necessarily represent the policies of the Department of Energy or the views of other Department of Energy staff members.  相似文献   

18.
China's economic boom in recent decades has stimulated consumer demand for animal products and consequently, a vast expansion in animal production. From 1978 to 2006, the number of animals increased by 322% for pigs, 209% for poultry, and 2770% for dairy cattle. The objective of the present study was to quantify nitrogen mass flow in China's animal production system at the national scale and to elucidate potential environmental implications. A comprehensive analysis was performed combining statistical records with data from the scientific literature and supplemental survey information. Results indicate that approximately 18 Mt of N flowed through the Chinese animal production system in 2006. Nitrogen input to the system was from various feed materials, including 6.8 Mt (38% of total) from roughage, 4.4 Mt (24%) from byproducts, 2.3 Mt (13%) from cereal grains, and 1.6 Mt (9%) each from crop residues and oilseed cakes, with the remaining N (16%) obtained from other feedstuffs. Nitrogen outputs from the system included edible animal products (2.4 t, 13% of total), nonedible animal parts (e.g., bones, skins) (3.8 Mt, 21%), and excreta (12 Mt, 66%). At the national level, the excreta would average 28 Mg (as excreted) and 90 kg N ha(-1) of cropland. However, at the provincial level, it varied from 1 Mg ha(-1) (5 kg N ha(-1)) in Qinghai to 97 Mg ha(-1) (243 kg N ha(-1)) in Sichuan. In regions with excreta in the intermediate rate (e.g., Hebei Province, 115 kg N ha(-1)) or high rare (e.g., Sichuan Province, 243 kg N ha(-1)), animal manure contributes significantly to nutrients polluting groundwater and/or surface waters. It is crucial for China to develop and implement proper management practices to maximum the beneficial use of the 12 Mt excreta N while minimizing its environmental footprint.  相似文献   

19.
Emergy (with an 'm') synthesis was used to assess the balance between nature and humanity and the equity among forest outcomes of a US Forest Service ecosystem management demonstration project on the Wine Spring Creek watershed, a high-elevation (1600 m), temperate forest located in the southern Appalachian mountains of North Carolina, USA. EM embraces a holistic perspective, accounting for the multiple temporal and spatial scales of forest processes and public interactions, to balance the ecological, economic, and social demands placed on land resources. Emergy synthesis is a modeling tool that allows the structure and function of forest ecosystems to be quantified in common units (solar emergy-joules, sej) for easy and meaningful comparison, determining 'system-value' for forcing factors, components, and processes based on the amount of resources required to develop and sustain them, whether they are money, material, energy, or information. The Environmental Loading Ratio (ELR), the units of solar emergy imported into the watershed via human control per unit of indigenous, natural solar emergy, was determined to be 0.42, indicating that the load on the natural environment was not ecologically damaging and that excess ecological capacity existed for increasing non-ecological activities (e.g. timbering, recreation) to achieve an ELR of 1.0 (perfect ecological-economic balance). Three forest outcomes selected to represent the three categories of desired sustainability (ecological, economic, and social) were evaluated in terms of their solar emergy flow to measure outcome equity. Direct economic contribution was an order of magnitude less (224 x 10(12)solar emergy-joules (sej) ha(-1)) than the ecological and social contributions, which were provided at annual rates of 3083 and 2102 x 10(12)sejha(-1), respectively. Emergy synthesis was demonstrated to holistically integrate and quantify the interconnections of a coupled nature-human system allowing the goals of ecological balance and outcome equity to be measured quantitatively.  相似文献   

20.
Chile and Peru produce almost 45% of world’s mine copper output. This situation reflects their natural endowment and mining tradition, but is also the result of development processes undertaken over the last decades. As a result, both countries multiplied its mine copper production in more than 3 times in the last 20 years. Mining labor productivity played a central role achieving these amazing growth rates. Although there is a consensus about the relevance of this variable for the mining industry, the specific factors behind labor productivity changes are not completely understood.  相似文献   

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