遥感与GIS支持下的成都市山地平原过渡地区生态安全及时空分异研究

发布时间：2018-03-08 16:12

  本文选题：遥感　切入点：GIS　出处：《四川师范大学》2017年硕士论文　论文类型：学位论文

【摘要】：近年来,随着人类活动强度及规模的不断扩大,导致了生态环境的破坏,使得区域的生态安全不断恶化。山地平原过渡地区具有不可替代的资源支撑、生态服务与环境调节功能的重要性,但生态环境脆弱,易发生次生地质灾害,目前我国对其关注不够,缺乏对这类地区生态安全的深入探讨,加强对山地平原过渡地区的生态安全方面研究具有非常重要的意义。本文依托“教育部重点实验室”、“省国土资源协同创新中心”科研平台和国家自然科学基金面上项目等,以成都市的山地平原过渡地区,即彭州市、都江堰市、崇州市、大邑县、邛崃市五个行政区为研究区域,以生态安全为研究对象,选取2000~2015 a的四期遥感影像为数据源,采用监督分类法提取土地利用变化信息;基于P-S-R模型构建研究区的生态安全评价指标体系;利用遥感和GIS技术获取植被覆盖度、土壤侵蚀敏感性、地表温度反演、生态系统服务价值等共20个指标值,再依次进行指标栅格化表达并按权重进行空间叠加,据此得到过渡地区2000~2015 a的综合生态安全数据,从像元和行政区两种尺度对研究区的生态安全状况进行分析;最后使用探索性空间分析法(ESDA)中的Moran's I、Getis-Ord General G、Getis-Ord Gi*和Local Moran's Ii指数对研究区的生态安全时空分异进行分析。得出以下结论:(1)整体而言,2000~2015 a过渡地区的生态安全处于中度安全的状态,但生态安全指数有减小的趋势。生态安全等级较高的区域主要是距城镇有一定的距离的西部和北部的山区和半山区,平原地区人类活动强烈,生态安全状态等级较低;都江堰市,大邑县和邛崃市的生态安全指数都高于其平均水平,而彭州市和崇州市的生态安全指数均低于其平均水平。随着经济的发展,主城区向外不断扩散以及一些乡镇的不断发展,生态安全指数由高变低。(2)四个时期、四种尺度下(Ⅰ500*500、Ⅱ1000*1000、Ⅲ1500*1500、Ⅳ2000*2000)的生态安全空间自相关效果均显著。Moran’s I值都是随着空间距离的递增而不断减小,即随着空间距离的增加以及研究尺度的扩大,研究区的空间相关性在不断减弱。四个年份的生态安全Moran's I值在小尺度500m*500m最大。(3)2000~2015 a,研究区内部的生态安全存在空间上的高值集聚模式。生态安全“冷点”区域主要分布在东部和南部的平原地区,以各个市县的主城区和一些较大的乡镇为核心,向外稳定扩散;生态安全“热点”区域主要分布在西部和北部的山区,该区域受人类活动影响小。(4)2000~2007 a和2008~2015 a两个时段的生态安全变化整体上呈现聚集分布,但局部差异性在逐步增强。2007~2008 a震后的生态安全变化仍存在一定空间集聚性。生态安全变化的四种类型区在空间上不断变化,以高—高型区域最多,低—低型次之,且这两种类型的扩散效应随时间的推移在逐渐减弱。
[Abstract]:In recent years, with the expansion of the intensity and scale of human activities, the ecological environment has been destroyed and the ecological security of the region has been deteriorating. The importance of ecological service and environmental regulation function, but the ecological environment is fragile, prone to secondary geological disasters, at present, our country does not pay enough attention to it, lack of in-depth discussion of ecological security in this kind of areas. It is of great significance to strengthen the research on ecological security in the transitional areas of mountainous plains. This paper relies on the key Laboratory of the Ministry of Education, the Scientific Research platform of the Provincial Land and Resources Cooperative Innovation Center and the National Natural Science Foundation of China, etc. Taking the mountain plain transitional areas of Chengdu, namely, Pengzhou, Dujiangyan, Chongzhou, Dayi and Qionglai as the research areas, taking ecological security as the research object, the four periods of remote sensing images from 2000 to 2015 a are selected as data sources. Based on P-S-R model, the ecological security evaluation index system of the study area is constructed. The vegetation coverage, soil erosion sensitivity and surface temperature inversion are obtained by remote sensing and GIS. There are 20 index values of ecosystem service value, and then the index rasterization expression is carried out and the spatial superposition is carried out according to the weight. According to this, the comprehensive ecological security data of the transitional area 20005a are obtained. The ecological security situation of the study area is analyzed from the pixel and the administrative region scale. Finally, using the Moran's Itis-Ord General Getis-Ord-Ord * and Local Moran's I I index in the exploratory spatial analysis method to analyze the spatial and temporal diversity of ecological security in the study area, the following conclusions are drawn: (1) the ecological security in the transitional area of 20002005a is in a moderately safe state as a whole. However, the ecological security index has a decreasing trend. The regions with higher ecological security grade are mainly mountainous and semi-mountainous areas in the west and north of China, which are far from the towns. The human activities in the plain areas are strong, and the ecological security level is lower than that in the plain areas. The ecological safety index of Dujiangyan, Dayi and Qionglai is higher than its average level, while that of Pengzhou and Chongzhou is lower than its average. The main urban areas continue to spread out and some villages and towns continue to develop, and the ecological security index changes from high to low. The effects of self-correlation of ecological safety in four scales (鈪，

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