基于景观异质性的云南省红河县生态风险评价研究

发布时间：2018-04-08 14:03

本文选题：景观异质性　切入点：景观干扰度　出处：《甘肃农业大学》2015年硕士论文

【摘要】：以云南省红河县为研究区域,根据景观生态学的基本原理,借用GIS技术和fragstats软件,对其景观结构,景观异质性进行分析,在此基础上选取多样性指数、分离度指数、破碎化指数、分维数倒数等一些基于异质性的指标表征景观干扰度和景观脆弱度,确定风险受体、生态终点,计算各研究单元内的生态风险值并对其评价。评价结果可对生态风险管理提供理论支持和决策依据,研究结果表明:(1)云南省红河县以林地作为基质,水域作为廊道,耕地、园地、草地等景观组分为斑块的基质—斑块—廊道模型的异质性景观生态系统。(2)由于自然灾害、人类活动等风险源的共同作用及风险受体的不同,各研究单元的生态风险值不同,本研究将13个乡镇作为评价单元,在景观异质性的基础上计算出不同的生态风险值,分别介于4.22~13.6之间,就人为干扰与自然环境的受到的损害而言,其中以迤萨镇的生态风险值最大,车古乡、浪堤乡、大羊街乡、乐育乡、宝华乡、甲寅乡、石头寨乡基本趋于同一水平,生态风险值基本处于4.2~5.9之间,生态风险值较低;三村乡、垤玛乡、洛恩乡的生态风险值介于处在5.9~7.6之间,生态风险值处于中等水平。(3)云南省红河县的县政府驻地迤萨镇人口密度最高,人为活动对生态环境的影响力最大,生态风险值最大,造成其可能的原因有:水生坏境的污染、功能区是否合理划分、人类活动、自然灾害的共同作用而导致生态风险值处于整个研究区域的最高水平,阿扎河乡、三村乡、垤玛乡、洛恩乡四个乡镇生态风险值处于一个中等较高的水平,这四个乡镇分布在整个研究区域的最南端和最西端,境内群山起伏、河谷狭窄、山势巍峨、峰峦起伏、沟壑纵横、地势险峻,决定了境内的景观组分相对单一,景观脆弱性程度较高,同时自然灾害明显,冬春干旱少雨,夏秋多雨多有山洪暴发,河水泛滥,外加人为活动的影响,造成这四个研究单元(乡镇)生态风险值较高,车古乡、浪堤乡、宝华乡等处于较低生态风险区,这些乡镇集中分布,地处整个研究区域的几何中心,沿四周分布,相对地势平坦、景观组分相对丰富,农作物生态旺盛,所承受的生态风险较低。(4)依据整个研究区域生态风险值的计算结果,就不同的研究单元和不同的风险等级提出相应的生态风险管理对策,为整个研究区域生态环境的改善与维护提供指导意见。
[Abstract]:Based on the basic principles of landscape ecology, the landscape structure and landscape heterogeneity of Honghe County, Yunnan Province, were analyzed by using GIS technology and fragstats software, and the diversity index and separation index were selected.Some indexes based on heterogeneity, such as fragmentation index and reciprocal fractal dimension, are used to characterize landscape disturbance and landscape vulnerability, to determine risk receptors and ecological endpoints, and to calculate and evaluate ecological risk values in each research unit.The evaluation results can provide theoretical support and decision basis for ecological risk management. The research results show that Honghe County of Yunnan Province takes forestland as matrix, water area as corridor, cropland, garden land, etc.Grassland and other landscape components are divided into patch matrix-patch-corridor model heterogeneity landscape ecosystem. (2) because of natural disasters, human activities and other risk sources and different risk receptors, the ecological risk values of each research unit are different.In this study, 13 villages and towns were used as evaluation units, and different ecological risk values were calculated on the basis of landscape heterogeneity, which were between 4.22 and 13.6. In terms of human disturbance and damage to natural environment,The ecological risk value of Yansa Town is the largest, Chegu Township, Longdyi Township, Dayang Street Township, Le Yu Township, Baohua Township, Jiayin Township and Shitouzhai Township tend to the same level basically, the ecological risk value is basically between 4.25.9and the ecological risk value is lower;The ecological risk value of Sancun Township, Yima Township and Luoen Township is between 5.97.6 and 5.97.6, and the ecological risk value is in the middle level.) the resident population density of the county government in Honghe County, Yunnan Province, is the highest, and the human activities have the greatest influence on the ecological environment.The ecological risk value is the largest, and the possible reasons are: pollution of aquatic environment, rational division of functional areas, joint action of human activities and natural disasters, resulting in the ecological risk value being at the highest level in the whole research area.The ecological risk values of four townships in Sancun Township, Yima Township and Luoen Township are at a relatively high level. These four villages and towns are distributed at the southernmost and westernmost ends of the whole research area, with ups and downs of mountains, narrow valleys, lofty mountains, and ups and downs of peaks and mountains.The gully is vertical and horizontal, and the terrain is steep, which determines the relatively single landscape component in the territory and the high degree of landscape vulnerability. At the same time, the natural disasters are obvious, the drought in winter and spring is less, there is more rain in summer and autumn, there are more flash floods, the river is flooded, and the influence of human activities is added.The ecological risk values of these four research units (villages and towns) are relatively high. Chegu Township, Longdike Township, Baohua Township and so on are in relatively low ecological risk areas. These villages and towns are concentrated and distributed in the geometric center of the entire research area, distributed around them.Relatively flat terrain, relatively rich landscape components, abundant crop ecology, low ecological risk, etc.) based on the calculation results of the ecological risk value of the whole study area,The corresponding countermeasures of ecological risk management are put forward for different research units and different risk levels, which can provide guidance for the improvement and maintenance of ecological environment in the whole research area.
【学位授予单位】：甘肃农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X826;P901

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