基于网格尺度的吴起县生态安全评价研究

发布时间：2018-02-14 06:40

本文关键词： 生态安全评价 P-S-R模型遥感技术网格单元吴起县　出处：《西安科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：近年来,随着环境问题的日益突出,生态安全问题逐渐引起了更多人的关注。自党的十八大将生态文明建设纳入国家“五位一体”建设布局总体方案之后,研究如何评价区域生态安全程度、保护区域生态安全成为关系人类社会可持续发展的重要课题。本文以吴起县为研究对象,在介绍了生态安全评价相关理论和方法以及吴起县生态安全现状的基础上,以经济合作与发展组织(OECD)提出的压力-状态-响应(P-S-R)模型为框架,基于遥感影像、人口统计数据和土壤侵蚀数据,运用GIS和遥感技术,构建了包括人类活动干扰指数、净初级生产力指数、平均斑块面积指数、土壤侵蚀指数、植被覆盖指数、人口密度指数、土地垦殖指数等7个指标在内的生态安全评价指标体系,并利用层次分析法软件yaahpV7.0,通过判断矩阵结合群决策的方法确定指标权重。利用Arcgis将研究区划分成5012个900m×900m的网格评价单元,运用综合评价模型融合多源异构数据获得了吴起县生态安全评价结果,通过统计表格和地图可视化两种方式进一步分析吴起县生态安全情况。结果表明:(1)吴起地区生态安全整体状况为一般状态,呈现出由南到北逐渐递减的趋势。(2)从空间分布水平差异来看,生态状况良好区域主要分布于沿河两岸,生态状况恶劣的区域主要分布于吴起县与定边县接壤地区;(3)从吴起县土地利用结构来看,以林地和草地为主要土地利用类型的区域生态环境状况最佳,生态系统结构相对完整,所受外部压力比较小,生态功能完善;以耕地和建筑用地为主要土地利用类型的区域生态环境等级差异较大,景观比较破碎,外部压力较大,生态环境等级差异明显;(4)就县域内各个乡镇而言,生态情况最好的是西南方向的白豹镇与长官庙镇,平均生态安全指数超过了 71,基本没有处于5级的区域。最差的是位于东北角的长城镇,平均生态安全指数为54.425,处于生态安全等级5级的区域在该镇占比达到4.461%。
[Abstract]:In recent years, with the increasingly prominent environmental problems, ecological security issues have gradually attracted more people's attention. Since the 18 Party of China brought the construction of ecological civilization into the overall plan of national "five-in-one" construction layout, How to evaluate the degree of regional ecological security and how to protect regional ecological security has become an important subject related to the sustainable development of human society. This paper takes Wuqi County as the research object. Based on the introduction of the theories and methods of ecological security assessment and the present situation of ecological security in Wuqi County, the pressure-state-response P-S-R model proposed by the Organization for Economic Cooperation and Development (OECD) is used as a framework and based on remote sensing images. Population statistics and soil erosion data, using GIS and remote sensing techniques, are used to construct a population density index, including human activity disturbance index, net primary productivity index, average patch area index, soil erosion index, vegetation cover index, population density index. The ecological security evaluation index system, which includes 7 indexes such as land reclamation index, With the help of the analytic hierarchy process software yaahp V7.0, the index weight is determined by combining the judgment matrix with group decision making. The study area is divided into 5012900m 脳 900m grid evaluation units by Arcgis. The ecological security evaluation results of Wuqi County were obtained by using comprehensive evaluation model to fuse multi-source and heterogeneous data. The ecological security situation of Wuqi County is further analyzed by statistical tables and map visualization. The results show that the overall situation of ecological security in Wuqi area is a general state. Showing a decreasing trend from south to north. (2) from the difference of spatial distribution level, the region with good ecological condition is mainly distributed along the banks of the river. According to the land use structure of Wuqi County, the regional ecological environment with woodland and grassland as the main land use type is the best, and the ecosystem structure is relatively complete. The regional ecological environment grade with cultivated land and construction land as the main land use type is different greatly, the landscape is relatively broken, and the external pressure is great. There is a clear difference in ecological environmental grade (4) as far as the villages and towns in the county are concerned, the best ecological conditions are the white leopard town and the chief temple town in the southwest. The average ecological security index is more than 71, and there is no 5 grade area. The worst one is Changcheng town in the northeast corner. The average ecological security index is 54.425, and the proportion of the area in the fifth grade of ecological security level is 4.461 in this town.
【学位授予单位】：西安科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X826

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