【作者】 李坚；

【导师】 张征；

【作者基本信息】 北京林业大学 ， 生态学， 2011， 博士

【摘要】 本文以滇池流域为研究对象,对该流域的自然状况与社会经济状况进行了较为系统的调查、分析与相关图件的制作。在此基础之上,对滇池流域的水土流失现状、特点、成因、危害、变化趋势等诸多方面进行了较为全面、系统的深度剖析,结合以上的研究成果,围绕滇池流域水土流失生态影响评价这一主题进行了以下方面的研究工作。(1)基于Arc GIS平台之上,对影响滇池流域水土流失生态环境状况的土地利用这一自然性指标,进行了斑块形状分维数的计算,计算得土地利用各斑块的分维值介于1.09～1.35之间,总分维值1.15。若不考虑水域影响,稳定性指数均介于0.2～0.5之间的土地利用类型面积占滇池流域土地总面积的80.18%,总体稳定性良好,并对这一分析问题的思路类推至土壤侵蚀这一人为指标的稳定性分析上。同时,本文将分形理论与生态敏感性评价结合起来,应用敏感性评价数学模型进行了滇池流域生态敏感区的区划,最终,将滇池流域划分为5个不同的生态敏感区,并提出了各敏感分区应该采取的各项简要措施。(2)基于Arc GIS平台之上,对影响滇池流域水土流失的其中两个因素水系与地形进行了盒维数计算,计算得出：滇池流域水系分维数1.07与滇池流域地形分维数0.93,基于对滇池流域水系与地形的分维数计算与分形特征分析之上,将影响滇池流域水土流失的另外两个因素坡度和高程纳入进来,取其坡度中值(2348m)与高程中值(31。),应用基于信息扩散原理改进的模糊综合评价模型对这四个影响因素进行了综合评价,得出滇池流域水土流失等级和综合评价指数分别为2级和2.26。(3)应用层次分析法构建了滇池流域生态环境状况指标体系,并应用生态环境状况指数法对滇池流域首次进行了生态环境质量评价,可得滇池流域生态环境状况分级值为0.31与滇池流域生态环境状况级别为差,即该地区的生态环境条件较为恶劣,人类生存环境恶劣。最后,将该评价结果与《滇池流域水污染防治“十五”计划》中的数据进行了比较,证明该评价方法可靠,在此基础之上,针对生态环境状况各指数计算结果,并结合滇池流域实际状况,对滇池流域提出了相关的生态环境状况改善建议,其中,包括滇池流域水土流失治理规划图与滇池流域水土流失各项治理措施图。综上所述,本文通过应用分形理论这一种方法论,并通过使用Arc GIS这一强大的空间数据管理与处理工具,对滇池流域水土流失进行了系统的生态影响评价研究,从而扩充和丰富了生态影响评价方法论体系,为生态影响评价研究注入新的血液,并为滇池流域和全国其他湖泊流域的生态安全保障提供新的思路。更多还原

【Abstract】 In this paper, natural condition and socioeconomic status of Dianchi lake basin were investigated and analysed, then some maps were drawed, such as geographic location of Dianchi lake basin. Current situation, characteristic, causes, damage and variation tendency of soil and water erosion were comprehensively and systematically analysed in Dianchi lake basin. The work contains three parts about soil and water erosion ecological impact assessment based on the fractal theory in Dianchi lake basin.(1) Based on fractal method and GIS technology, the naturalness index of land utilizationcan be classified into 5 types:cropland, woodland, grassland, water land, industrial and residential areas, and analysis on fractal dimension of Dianchi lake basin in Yunnan province. The algorithm is a fractal dimension expression about area and perimeter. The results indicate that land use type can be described with fractal structure. Fractal dimension (D) values vary from 1.09 to 1.35 in the case application of Dianchi lake basin. The D of land use types reflects the degree of complexity, stability and developing trend. When the value of fractal dimension (D) is 1.15, namely D is critical value; the change mode of land use types means Brownian motion. The value of D is closer to the critical value, the stability of land use type is worse, and the complexity of land use type is higher. Without considering the impact of water land, the stability indexes of 80.18 percent of study areas are between 0.2 and 0.5, which means the total stability is in a good condition. Due to ecosystem sensitivity evaluation is very important to the stability analysis of regional ecological system, then the fractal theory combined with ecological sensitivity evaluation were used together for the ecological sensitivearea divisions in Dianchi lake basin. Finally, the study area was divided into five different ecological sensitivearea, and brief measures would be put forward to them.(2) Based on GIS technology, two factors of impacting soil erison which are the water system and terrain would be made the fractal value calculation. The results show that the value of stream fractal dimension (Db) is 1.07and terrain fractal dimension (Db) is 0.93. Then, the other two factors of impacting soil erison which are the mid-value of slope and the mid-value of elevation combined with the value of stream fractal dimension and the value of terrain fractal dimension were applied to the improved fuzzy comprehensive assessment model based on information diffusion principle. The result shows that the level of soil and water erosion is 2 and comprehensive evaluation index is 2.26 in Dianchi lake basin.(3) The system of eco-environmental appraisal index was established by using the Analytical Hierarchy Process (AHP) model in Dianchi lake basin. Using the related data, the ecological index (EI) of this basin in 2005 was assessed. The results show that grading value of eco-environmental status is 0.31 which is compared with the related value of the "water pollution prevention in Dianchi lake basin "five-year" plan". Then, the relevant improved suggestion was put forward according to the result. Finally, map of soil and water erosion treatment plan and map of soil and water erosion control measures were drawed according to the actual circumstances of Dianchi lake basin.To sum up, through the application of fractal theory that is a methodology, and through the use of Arc GIS that is a strong space data management and treatment tool, ecological impact assessment were systematically taken for the soil and water erosion of Dianchi lake basin, which has expanded and enriched the ecological impact assessment methodology system, which has injected new blood to ecological impact assessment, and has provided a new thinking for ecological security in Dianchi lake basin and the other lakes.更多还原