【作者】 刘东霞；

【导师】 卢欣石；

【作者基本信息】 北京林业大学 ， 草业科学， 2007， 博士

【摘要】 近几年,由于各种自然因素变化和人为因素的影响,致使呼伦贝尔草地生态环境日趋恶化。对草地生态环境进行脆弱性分析,以及区域生态承载力评价,对于草地合理保护利用和区域可持续发展具有重要现实意义。本研究以陈巴尔虎旗为例,采用野外调查和室内分析相结合的手段,借鉴了国内外有关生态环境脆弱性评价模型和生态承载力模型,以图像数据与统计资料为基础数据,建立了陈巴尔虎旗草地生态环境脆弱性评价模型和生态承载力模型,通过分析讨论,可以得到以下结论:(1)导致生态环境脆弱的因素有自然因素和人为因素两个方面,地质历史时期的构造运动为呼伦贝尔草地脆弱性奠定了特殊的地貌格局和脆弱的地表物质基础;自然条件的严酷性、气候的波动性、使这一地区成为对全球变化响应的敏感带;不合理的人类活动急剧了草地脆弱化的进程。(2)生态环境脆弱性评价,借助GIS技术手段,采用空间主成分分析法,通过各主成分来确定权重,不仅减小了主观随意性,而且消除了评价之间的重叠信息;GIS具有强大数据计算分析功能,计算过程中提取全部的主成分,大大的提高了计算精度,正是由于空间主成分分析方法具有上述优点,在生态环境脆弱性评价中具有很好的应用前景。(3)陈巴尔虎旗的生态环境状况总体上属于轻度脆弱水平,从东北向西南随着自然条件、气候因素、资源开发利用状况变化,生态环境状况有逐渐变劣的态势,生态环境恶劣地区主要分布于海拉尔河和额尔古纳河流两岸。(4)草地退化是造成生态环境脆弱性的重要贡献因子,但不是生态环境脆弱性的决定因子,而生态系统的脆弱性由地形地貌、气候条件、土壤和植被状况共同来决定,草地脆弱性程度与退化程度之间并不是一一对应的关系。(5)生态承载力评价模型选取人口承载力和牲畜承载力以及人口容载率和牲畜容载率作为评价指标,既对草地的利用状况做出了合理的评价,又对区域的可持续发展进行了评价,评价指标选择合理。另外,草地生产力统计时,利用了GIS技术,考虑了草地生态环境的脆弱性,引入草地可利用指数,从草地可持续利用的角度考虑草地保护和利用。(6)随着生态环境脆弱程度的加大,区域的牲畜承载力呈递减的趋势。人口承载力由于受社会、经济、自然等多方面因素的影响,与区域生态环境脆弱性程度之间没有明显的对应关系。(7)人口容载率和牲畜容载率的评价结果表明,八个苏木(镇)中有五个苏木(镇)牲畜出现超载现象,而人口仅宝日希勒镇和巴彦库仁镇超载之外,绝大部分地区都没有超载。造成生态环境恶化主要是由于人均牲畜牲畜占有量较大,牲畜数量发展较快。更多还原

【Abstract】 Resent years, because of the influences of nature factors and human activities, the eco-environment of the Hulunbeier steppe was gradually worsen. Evaluation of eco-environmental vulnerability and regional ecological carrying capacity had significently importance and realistic meaning for the regional sustainable development. In this study, two evaluation models of eco-environment vulnerablility and ecological carrying capacity were constructed based on the vector datus and statistic datus. Results are as following:(1) The causes of eco-environmental vulnerability of grassland were the outcomes of interaction of nature and the human beings. Among these reasons, the loose soil texture, which was formed in the fluviolacustrine sediment during Quaternary, establish the physical ground. Then harsh nature condition and fluctuant climate lead this area to a sensitive region. Addition, unreasonable mankind’s activities, such as over-cutting forest, over-grazing grassland, reclamation and so all accelerated the process of vulnerability.(2) In order to analyze eco-environmental vulnerability, geographical information system (G1S) technologies were adopted, an eco-environmental evaluation model was developed using spatial principle component analysis method. The spatial principle component analysis, using coefficients of linear correlation offers the possibility to weight the contribution of factors. This method not only reduced the subjective and arbitrary, but also eliminated the overlap between the evaluation factors. GIS as a powerful tool for ecological environment assessment, cannot only supplied spatial data analysis platform, but also possessed calculation function. In this study, all principle components were extracted to improve the precision.(3) In general, Eco-environmental state of Chenbaerhu Banner was belonged to relatively slight vulnerable level. Eco-environment vulnerability in study area presented distinct geographical horizontal-belt distribution. From northeast to southwest the eco-environment was gradually deteriorating with the changes of natural conditions, climatic factors, exploitation of natural resources. Heavy vulnerable level distributed in two sides of the Hailar River and Argun River.(4) Grassland degradation made a greater contribution to the eco-environmental vulnerability, but it was not the determining factor. And the eco-environmental vulnerabilituy was dicided by the factors of topography、climate conditions、 soil characters and vegetations and so all, so the degree of eco-environmental vulnerability were not corresponding to that of grassland detradation.(5) It is Ecological carrying capacity evaluation model was developed using the human carrying capacity and the livestock carrying capacity and the rate of population accommodation and the rate of livestock accommodation as indicators. It not only reasonably evaluated the status of exploitations of grass, but also estimated the level of regional sustainable development. Meanwhile, the indexes of available grass were introduced into the ecological carrying capacity evaluation model, considering the eco-environmental vulnerability.(6) with the degrees of eco-environmental vulnerability increased, the levels of reginoal livestocks carrying capacities were increased.while human carrying capacity had not obvious correlation to the eco-environmental vulnerability due to it was influnced by soscial fators、ecnomic factors and natural factors and so all.(7) chenbaerhu banner included eight towns all together, livestocks had existed overloading in five towns of them, while the population did not appeared over carrying, exept of baorixile town and bayankuren town. So deterioration of the ecological environment was mainly due to the fast development of livestocks.更多还原