【作者】 张平；

【导师】 刘普幸；

【作者基本信息】 西北师范大学 ， 自然地理学， 2011， 硕士

【摘要】 据研究,近几十年来,全球生态环境正在进一步恶化,特别是全球气候变暖、臭氧层破坏、酸雨、水污染、土地退化、全球森林危机、生物多样性减少、毒害物质污染与越境转移等八大问题,正威胁着人类的生存。为了解决现实的和潜在的环境问题,协调人类与环境的关系,保障经济社会的可持续发展,各国政府就环境保护方面达成了广泛的共识,以此为契机,生态环境研究很快成为当前研究的热点。我国自改革开放以来,经济快速发展,但生态破坏和环境污染相当严重。目前,政府已提出科学发展观和构建和谐社会的发展理念,这为生态环境研究提供了良好的社会氛围和政策支持。我国西北干旱区面积广大,绿洲是干旱区人民赖以生存的核心场所。但近年来,也出现了河流缩短、湖泊萎缩或干涸、水质咸化及污染趋势加剧、土地沙漠化、土壤盐渍化、农田污染、病虫害蔓延等生态问题。面对这种严峻的现实,如何用全新的视角审视绿洲,正确认识绿洲的功能和发挥绿洲的作用就成为新的研究课题。瓜州绿洲地处河西走廊西段,由疏勒河水系孕育而成,其开发历史悠久,绿洲农业发达。但近年来,随着人口急剧增加,水土资源开发的规模越来越大,并由此引发了一系列生态问题,如土地沙漠化、土壤盐渍化、草场退化等。为了揭示其生态退化的运行机制,为今后生态恢复重建提供科学依据,本文以P-S-R模型为基础,并结合瓜州绿洲实际情况,从生态环境质量、生态环境压力、社会经济状况等三方面筛选出14项指标构建瓜州绿洲生态稳定性评价指标体系,并把评价结果划分为很稳定、稳定、潜在不稳定、不稳定、极不稳定五个等级。运用熵值法确定指标权重,运用模糊综合评价法进行生态稳定性状况综合评价。结果表明:1991-2009年,瓜州绿洲生态稳定性综合评价指数介于0.33-0.63之间,平均为0.49,处于潜在不稳定状态,并向不稳定性状态发展。经过分析得出:气候干旱、水资源不合理的开发利用、大量移民是造成瓜州绿洲生态系统非良性发展的主要原因。最后,针对造成瓜州绿洲生态失稳的主要原因,提出了相应的防御对策。更多还原

【Abstract】 According to study,in recent decades,Global eco-environment has been coming forth a deteriorism tendency.Human existence and development is being threaten by eco-crisis,Such as global change, ozonosphere destroying, acid rain,water pollution,soil degeneration,global forest crisis,biologic diversity decreasing, toxicant pollution and cross the boundary illegally etc.The government in all the word has had a new cognition about the importance of protecting environment for solving the practical and potential problem of environment to assort with the relation of human and environment.Therefore,the study on environment has been a current hotspot quickly.Our national economy has a quick tempo from reformation and opening,but biology destroying and environment pollution is very serious.Currently,the government has put forward a thought of scientific development and constructing harmonious society.The thought provide a good social atmosphere and policy sustaining.The arid area is large in the northwest of china.The oasis is the most important location of people in the arid area for survival.But the problem of biology is serious,such as river shortening,lake shrinking or drying up,water becoming salty and pollution being more serious,land degeneration,soil salinization,farmland pollution,pest spreading etc.In the face of such austere fact,it is a new research task that how to use a new angle of view to scan oasis and know function of oasis.Guazhou Oasis is located at the western end of HexiCorridor,It has come into being by Shule River.It has a long history,Oasis Agriculture is developed.But lately,with population increasing,the exploitation of water and soil is excessive,The problem of biology is appearing,such as land degeneration,soil salinization,meadow degeneration,etc.For opening out the mechanism of biology degeneration to provide scientific basis of resumptive construct of biology.This paper design a assessment index system of ecological stability in Guazhou Oasis based on the P-S-R mode. The indexes are selected from three aspects which include the ecological quality,ecological pressure and socio-economy status.Entropy method is used to determine the weight of index system.Utilizing Fuzzy Comprehensive Evaluation Model to calculate the comprehensive values.The result shows that the ecosystem in Guazhou Oasis is potentially unstable.The comprehensive values are between 0.33 and 0.63,Average is 0.49.And the trend is from potential unstability to unstability. Analysis points out that this result is due to climate extreme drought ,irrationality use of water resourse and a great deal migration.Finally,the defense countermeasures of ecological risk are presented.更多还原