Emergy Analysis Of Oasis Agricultural Eco-Economic System In Arid Region

How to understand and cope wisely with the relationship between man and nature, environment and economy, achieve sustainable development, is an intricate problem to mankind .As an unique landscape in arid area, oases support the regional sustainable development, and have become the most important issues in the field of sustainable development research in aridland.Wuwei Oasis, which majority locates in Liangzhou District, is the largest one in Hexi corridor, Gansu Province, and is also an important grain production base, "Number One Granary" in Gansu province. Due to most dense population, shortage of water resource and severe eco-environmental degradation situations among three inland watersheds in Hexi corridor in Gansu province, Liangzhou District has been a focus on how to promote social and economic development in harmony with population, resource and environment, achieving sustainable development in dryland.The emerging emergy analysis provides an approach which can scale and analyze the relationship between nature environment and human economy. Most applications of emergy analysis on regional sustainable development research paid more attention to several indexes, and in static viewpoint usually, this paper endeavors to give a detailed emergy evaluation of Liangzhou District, applying various indexes such as ecological flow Input/Output and Net Emergy Output Ratio, Environment Loading Rate, Emergy Utilization Intensity, Emergy Investment Rate indexes etc., and in static (2005) and dynamic (1986 to 2005) aspects. The main conclusions are as follows.Firstly, the total input emergy and total output emergy of agricultural ecological economic system in Liangzhou District is on the rise in past 20 years, and the industrial assistant emergy, outside the system, were dominated in the agricultural input emergy, the quantity of environment resource input emergy inside system is also on the rise, mainly implied increasing of water resources consumption; the total output emergy was absolutely dominated by plant output emergy at first, gradually transformed to combination output emergy of agriculture, livestock and pasture, as well as forestry and fishery. The main emergy indexes showed obvious trend that the development direction of agriculture in Liangzhou District transform from traditional to modern agriculture,, the level of agricultural modernization was increasingly enhanced. As the system is far from high input high output state, it still has a great potential.Secondly, In past 20 years, the index curve of the total input emergy, per capita...