【作者】 赵毓梅；

【导师】 赵先贵；

【作者基本信息】 陕西师范大学 ， 环境科学， 2008， 硕士

【摘要】 人类面临的生态与社会矛盾不断加剧,生态经济系统可持续发展逐渐引起了全球的关注,并成为研究的热点问题之一。我国幅员辽阔,自然条件差异很大,社会经济发展又极不平衡,因此走生态与经济建设并行的区域可持续发展之路是我国的自身需要和必然选择。吴起县位于延安地区西北部,县内沟壑密布、土地破碎、以及长期以来的乱砍乱伐、超载放牧导致生态环境日趋恶化,严重制约了当地的社会经济发展。自1998年开始,吴起县积极响应党中央发出“再造一个山川秀美的西北地区”的伟大号召,成为全国退耕还林第一县,被水利部列为“全国水土保持生态环境建设示范县”。近年来,大规模的石油开采带动了当地经济发展,同时,也对生态环境造成了严重的污染。因此,研究生态经济系统可持续发展状况具有重要的现实意义。本文以吴起县为研究对象,利用生态足迹模型、能值分析理论和基于能值分析的生态足迹模型,定量分析、评价自1995年以来吴起县生态经济系统发展的可持续性。主要结论如下:(1)生态足迹模型的评价结果表明,1995年以来吴起县的人均生态足迹呈现出快速增长的态势,2006年比1995年增加了2.9744hm~2,年均增长0.2540hm~2。而人均生态承载力呈现出较为缓慢的增长态势,2006年比1995年增加了0.8716hm~2,年均增长0.0792hm~2。12年间,人均生态足迹均高于人均生态承载力,一直表现为生态赤字。且生态赤字呈现增长的态势,从1995年的0.0181hm~2增加到2006年的1.7747hm~2,12年增长了1.7566hm~2,年均增长量为0.1597hm~2。自1995年以来,当地的石油产业发展迅速,拉动了电力的使用量,导致人均能源消费量大幅度上升,人均生态足迹呈现出上升的趋势。因人均生态承载力趋于稳定,所以人均生态赤字的变化主要取决于人均生态足迹的变化。吴起县的发展模式主要是通过消耗自然资源存量来弥补生态承载力的不足,其中能源消费主要以电力为主;生物资源的消费主要以农产品为主,这种对自然资源的过度依赖,是吴起县出现生态赤字的主要原因。自1995年以来均表现为生态赤字,说明生态经济系统整体上处于不可持续发展的状态。(2)能值分析理论的评价结果表明,自1995年以来吴起县的生态经济系统能值产出率均大于1,说明生产过程产出的能值大于生态经济系统投入的能值。能值产出率在1.5～2.5之间波动,能值产出率较高,这主要是由于吴起县投入的购买能值(工业辅助能和可更新有机能)较低,无偿利用的环境资源能值很高;生态经济系统环境负荷率约为3.00,说明吴起县承受生态环境压力较小,进一步说明:吴起县在提高经济效益的同时,注意到了环境保护和提高生态效益,使得生态环境压力在其承受的范围之内;受能值产出率和环境负荷率变化趋势的影响,生态经济系统可持续发展指数均小于1,且可持续发展指数总体上呈现出非匀速下降的趋势,说明当地为资源消耗型发展且趋向于不可持续发展的方向,下降的趋势说明逐步向更不可持续方向发展。低投入换来高产出的表象并不是真正的高产出,这将最终导致生态经济系统进入不可持续状态。(3)基于能值分析理论的生态足迹模型的评价结果表明,吴起县自1995年以来生态经济系统均表现为生态赤字,说明发展状态的不可持续,人均生态赤字和人均生态足迹曲线呈现出相同的变化趋势,说明吴起县的人均生态赤字主要取决于人均生态足迹。人均生态足迹最大的是耕地,而且12年来均高于其它类型的生物生产土地面积,表明当地居民对耕地的依赖性很强:其次是草地和建筑用地的人均生态足迹总体上呈现出上升的趋势:草地的人均生态足迹在2005年达到了0.6852hm~2,是2002年的6.68倍:建筑用地的人均生态足迹2005年达到了0.3956hm~2:林地的人均生态足迹在1995～2000年间呈现出逐年上升的趋势,在2000年达到了0.2620hm~2,之后出现了骤降趋势,在2003年之后开始回升:化石燃料用地的人均生态足迹呈现出逐年上升的趋势,由1995年的0.00004hm~2,上升到2005年的0.0712hm~2;水域的人均生态足迹在0.0044～0.0119hm~2之间,变化幅度较小,说明吴起县人们对水域的依赖性较弱。吴起县1995～2006年的人均生态赤字与人均生态足迹关系密切,而人均生态承载力的影响较小。但就生物资源消费量和能源资源消费量来比较,人均生态足迹主要受生物资源消费量的影响。人均生态足迹与降雨量有强负相关关系,与人口数量没有强负相关关系。吴起县自1995年以来均表现为生态赤字,说明吴起县经济发展处于不可持续状态。(4)对所采用的三种评价方法的对比分析表明,吴起县自1995年以来均表现为生态赤字。但采用基于能值分析理论的生态足迹模型计算的生态赤字出现了较大的波动,这与当地的实际情况不符,说明了该方法不能真实地反映当地的可持续发展状况。将生态足迹模型与能值分析理论进行比较,发现生态足迹模型侧重于研究人类对于生态环境的需求量,全面地反映了人类生活质量与资源禀赋两方面的信息,与可持续发展研究联系得更为密切,更适合于可持续发展的测度研究,有着较好的应用前景,是三种方法中最好的一种。但是生态足迹模型存在诸如模型过于理想化以及不能够准确地反映生态系统的承载能力等问题,需要进一步完善。更多还原

【Abstract】 With the ecology-society contradiction becomes worsen and worsen,the issue of development of agricultural eco-economic system has been aroused great attention in the world. China’s social and economic development is very uneven and regional differences are significant because of the vast territory and various natural conditions in different areas.Therefore the sustainable development of both ecological construction and economic construction are of the same importance to China.Wuqi County is located in the north-west area in Yah’an district.It’s mountainous physiognomy and broken land that is caused by over-deforestation and over-grazing animals have enormously constrained the local development.Since 1998 Wuqi government has actively responded to the call of the central committee of CPC-Rebuild a new and graceful North-west area and returned land for farming and forestry first and was honored "Model County for Conservation of Water and Soil and eco-environmental Construction" by Ministry of Water Resources.However,in recent years the massive oil production has brought not only some business benefit but serious pollution problems.Based on a research in Wuqi County the author adopts the ecological footprint model,emergy analysis and the model of ecological footprint calculation based on the theory of emergy analysis to discuss the possibility of its sustainable eco-economic development since 1995 till now.Following are the conclusions:(1)The result from the ecological footprint model shows that since 1995 the average ecological footprint in Wuqi County has increased a lot:1995-2006 the increase is 2.9744hm~2 and the annual increase is 0.2540hm~2;while the average ecological capacity increases comparatively slow:1995～2006 the increase is 0.8716hm~2 and the annual increase is 0.0792hm~2.During the 12 years the average ecological footprint is higher than the average ecological capacity and the ecological deficit keeps increasing from 0.0181 hm~2 in 1995 to 1.7747 hm~2 in 2006 and the annual increase is 0.1597hm~2.Since 1995 the local oil production has led the massive use of power and a increase of average emergy consumption and the average ecological footprint is in an up-tendency.The average ecological deficit changes with the average ecological footprint for the stability of average ecological capacity.Its development relies on the natural resources consumption esp.the electronic power which is the key reason to the ecological deficit.It can be drawn that its eco-economic system is not in the sustainable development. (2)The result from emergy analysis shows that since 1995 EYR of Wuqi County is more than 1, that is to say,EYR of producing is more than that of invest.EYR is between 1.5-2.5 and the high EYR is contributed to the low purchase emergy value(unrenewable industrial emergy and renewable organic emergy) and high environmental emergy value that is used without compensation.The environmental ELR is about 3.00 which show that its environmental pressure is not big and the government has paid attention to the environmental protection when enhancing the economic benefit. The sustainable development indexes are less than 1 and the general sustainable development index shows the non-constant velocity decline tendency;under the influence of EYR and ELR eco-system index of the sustainable development is less than 1 and the general sustainable developmental index shows non-velocity decline tendency.These show that the local development is based on the resources consumption and it cannot be called high-producing in a real sense.(3)The result from the model of ecological footprint calculation based on the theory of emergy analysis shows that since 1995 the eco-economic system is in ecological deficit that is a sign of unsustainable development.The same tendency showed in the average ecological deficit and average ecological footprint indicates that its average ecological deficit is due to the average ecological footprint.The statistics also show that the local people mainly rely on the arable land to make a living.Second is the average ecological footprint of pasture and buildable area is in the up-going tendency.The average ecological footprint of agricultural products is up to 0.6852hm~2 in 2005 which is 6.68 times than that of 2002;the average ecological footprint of buildable area is up to 0.3956hm~2 in 2005 which is 3000 times than in 1995;the average ecological footprint of forest is in a up-tendency in 1995～2000 and up to 0.2620 hm~2 in 2000,the line keeps up-going though there is a steep down-going change in 2003;the average ecological footprint of fossil emergy is in a crease from 0.00004 hm~2 in 1995 to 0.0712 hm~2 2005;the average ecological footprint of water area is between 0.0044～0.0119 hm~2 that is a of a small change and shows that the local people rarely rely on the water area.There is a close relationship between the local average ecological deficit and the average ecological footprint,while the average ecological burden is small.However,as to the comparison of the ecological resources consumption and the emergy consumption,it can be concluded that the average ecological footprint is mainly influenced by ecological,resources consumption and there is no significant sign of the influence from the average emergy consumption.(4)By adopting the three evaluation methods the research shows that Wuqi County has been in the ecological deficit since 1995.However,there exists a big wave in the model of ecological footprint calculation based on the theory of emergy analysis when the ecological deficit is calculated. Such a result is not in conformity with the local situation,which shows that the model of ecological footprint calculation based on the theory of emcrgy analysis doesn’t reflect local sustainable development factually.With a further comparative analysis of the ecological footprint model and emergy analysis,the result shows that ecological footprint model emphasizes particularly on the demand of ecological environment of human,reveals the resource endowment and the living quality of people more comprehensively and connects with the study of sustainable development more closely.So the ecological footprint model is more suitable for the evaluation of sustainable development,and it has the prospect of application widely.The ecological footprint model is considered as the best evaluation method to evaluate the sustainable development.However,the ecological footprint model is too much idealistic and doesn’t affect the ecological deficit accurately, which needs to be improved.更多还原