甘肃省生态经济系统的能值分析

Study on emergy analysis of Gansu ecological-economic systems

能值理论是研究生态经济系统结构和功能的新理论 ,它以太阳能值为统一尺度 ,解决了不同类型能量之间无法进行核算的问题 ,为我们提供了一种新的能量分析理论方法 .应用能值理论 ,对甘肃省生态经济系统进行了能值分析 ,并对甘肃省总的能值用量、能值货币比率、能值自给率、人均能值用量、能值密度等一系列能值指标进行了定量研究 。

As economic and ecological support systems become more interdependent,new disciplines are needed to 'bridge the gap' of understanding between human and nature.As we know that a natural systems and a human economic system are all tied to energy flow.Traditional energy analysis,however,has been criticized in many aspects.One is that various energy types,including materials and services,cannot be compared or totaled only by energy quantity.Emergy created by H.T Oudm is a new method to evaluate natural capital and ecosystem services.Emergy is defined as the energy of one type required in transformations to generate a flow or storage.Solar Emergy of a flow or storage is the solar energy required to generate a flow or storage.Its units are solar emjoules (abbreviated sej).An Emergy analysis of Gansu ecological economic systems has performed in order to study its sustainability and emergy use.Indices and ratios of Gansu based on Emergy flow were evaluated and a comparison with indices and ratios of other countries or areas was performed.The Emergy flow of Gansu was divided into 5 parts:(1) Emergy flow of renewable resources;(2) Emergy flow of products of renewable resources;(3) Emergy flow of non renewable resources;(4) Emergy flow of money;(5) Emergy flow of waste.In 2000,The total Emergy use(U) of Gansu was 1.41×10 23 sej,it includes Emergy flow of renewable resources(R) 2.99×10 22 sej(Geopotential energy in dispersed rain);Emergy flow of non renewable resources (N) 1.15×10 23 sej;Emergy flow of import (IMP) 1.03×10 21 sej;Emergy flow of export (EXP) 4.24×10 21 sej.Emergy flow of money was 1.08×10 23 sej,Emergy flow of waste 8.51×10 20 sej.Some main indices and ratios of Gansu based on Emergy flows were performed:emergy self sufficiency ratio (ESR) was 99.27%.Emergy per person (U/Pop) was 5.62×10 15 sej.Emergy density (U/Area) was 3.11×10 15 sej/m 2.Emergy/dollar ratio (U/GDP) was 11.88×10 12 sej/$.Ratio of Electric Power to total Emergy use was 11.36%.Environmental loading ratio (ELR) was 3.73.Carrying capacity based on renewable Emergy was 532×10 4 person.Developed Carrying capacity (8×(R/U) ×Pop) was 4 250×10 4 person.Ratio of waste to total Emergy used was 0.602 3%.Through the research,following results and suggestions were presented:(1) The Emergy self sufficiency ratio of Gansu was 99.27%.It means that Gansu ecological economic systems were main relied on the local resources.The Gansu ecological economic systems were not open and sustainable systems.On the other hand,there is a great potentiality to develop the resources of Gansu.So,attraction of more foreign emergy (capital,information,technology) is the very important tactic to the sustainable development of Gansu.(2) Emergy density is much lower,which shows that Gansu is an agricultural area.In 2000,non renewable resources are 81.11% of its total Emergy use,which shows that economic development is mostly depended on the devotion of raw materials.So Gansu should speed up to develop knowledge concentrated industry for future sustainable development.(3) In 2000,net loss of top soil Emergy is 1.68×10 22 sej.It is 11.93% of total Emergy use of Gansu,which shows that soil loss is a very important problem in Gansu province.It is a key for the further development of agriculture,forestry,and animal husbandry in Gansu province.So the projects of returning farmland to forest (grassland),protect natural forest,and desert control are good for controlling of soil loss.