鄱阳湖南矶湿地信息提取及景观格局动态变化研究

发布时间：2018-04-13 21:40

本文选题：南矶湿地 + 水位　；参考：《江西师范大学》2016年硕士论文

【摘要】：湿地是地球上最重要的生态系统之一,对自然界生物多样性维持和人类生态环境的构建起到巨大作用。加强对湿地景观格局变化研究,可以了解湿地景观格局的时空演变规律,对湿地生物多样性的维持、保护以及促进社会经济发展方面具有重要意义。由于近年来鄱阳湖南矶湿地受自然和经济等因素影响,其生态系统遭受严重威胁和破坏,对其湿地功能发挥造成了巨大影响。因此,本文以鄱阳湖南矶湿地国家级自然保护区为研究区域,利用1973-2010年20期Landsat系列影像和2013年1期GF-1影像为数据源,分别采用决策树分类和面向对象分类方法对其湿地信息进行提取。最后结合ArcGIS、ENVI以及Fragstas4.2等软件对其景观格局动态变化进行计算和分析。本文主要成果有:(1)构建南矶湿地决策树分类模型和面向对象分类规则。本研究通过构建南矶湿地决策树分类模型,并利用该模型对Landsat系列影像中湿地信息进行快速提取。而针对GF-1影像,本研究构建了面向对象分类湿地信息提取规则,其分类结果获得较高的分类精度(94.3275%)和Kappa系数(0.9324)。(2)根据2013年冬季GF-1影像解译结果和景观格局时空特点,结果表明:水体、泥滩、草洲是南矶湿地主要湿地类型;水体类型破碎化程度最高,泥滩类型景观形状最复杂;研究区西南部景观破碎化程度和多样性均高于东北部。(3)利用1973、1984、1999、2003和2010年5期相近水位影像解译结果,通过分析南矶湿地4个不同阶段(1973-1984年、1984-1999年、1999-2003年、2003-2010年)的景观动态度、景观转移矩阵和景观时空变化,得出了不同阶段各湿地类型转移变化规律。总体表明近37年来南矶湿地经历落-落-起-落四个不同变化阶段,其中2003-2010年南矶湿地类型转化更剧烈,转移范围更广。(4)分别从类型水平和景观水平上对近37年来南矶湿地景观格局时空变化进行分析。结果表明,近37年来南矶湿地景观有趋于破碎化和小型化方向发展,景观形状趋于复杂化,且多样性呈减少趋势;南矶湿地破碎化、景观形状和多样性指数较大的区域都集中于保护区西南部。(5)通过对不同水位情境下南矶湿地景观格局计算和分析。结果表明:水位变化与景观破碎化、景观多样性和景观均匀度指数呈负相关关系,而与景观蔓延度指数呈明显的正相关关系。
[Abstract]:Wetland is one of the most important ecosystems on the earth, which plays an important role in the maintenance of natural biodiversity and the construction of human ecological environment.The study of wetland landscape pattern change can understand the temporal and spatial evolution law of wetland landscape pattern, which is of great significance in maintaining, protecting and promoting social and economic development of wetland biodiversity.In recent years, the Nanji wetland of Poyang Lake has been seriously threatened and destroyed by natural and economic factors, which has a great impact on its wetland function.Therefore, this paper takes Nanji Wetland National Nature Reserve of Poyang Lake as the research area, using 20 Landsat series images from 1973 to 2010 and 1 GF-1 image from 2013 as the data source.Decision tree classification and object-oriented classification are used to extract wetland information.Finally, the dynamic changes of landscape pattern are calculated and analyzed by using ArcGIS-ENVI and Fragstas4.2.The main achievements of this paper are as follows: 1) constructing the decision tree classification model and object-oriented classification rules of Nanji wetland.In this study, the decision tree classification model of Nanji wetland was constructed, and the wetland information was extracted quickly from Landsat images.For GF-1 images, the rules of information extraction for object-oriented wetland classification were constructed, and the classification results obtained a higher classification accuracy (94.3275) and Kappa coefficient (0.9324). According to the results of interpretation of GF-1 images and spatial and temporal characteristics of landscape pattern in winter 2013,The results showed that the main wetland types in Nanji wetland were water body, mudflat and Caozhou, and the water body had the highest degree of fragmentation, and the landscape shape of mudflat type was the most complex.The degree and diversity of landscape fragmentation in the southwest of the study area were higher than those in the northeast of China.) the landscape dynamics of Nanji wetland during 1973-1984 to 1999-2003 and 1999-2003 to 2003-2010 were analyzed by using the interpretation results of similar water level images in 1973-1984 and 2010, respectively.Based on landscape transfer matrix and landscape temporal and spatial changes, the changes of wetland types in different stages were obtained.In the past 37 years, Nanji wetland has experienced four different stages: falling, falling, rising and falling, among which the transformation of Nanji wetland type was more intense in 2003-2010.The spatial and temporal changes of landscape pattern of Nanji wetland in recent 37 years were analyzed in terms of type level and landscape level.The results show that the landscape of Nanji wetland tends to be fragmented and miniaturized in recent 37 years, the landscape shape tends to be complicated, and the diversity of Nanji wetland tends to decrease.The landscape shape and diversity index were all concentrated in the southwest of the reserve. The landscape pattern of Nanji wetland was calculated and analyzed under different water level.The results showed that there was a negative correlation between water level change and landscape fragmentation, landscape diversity and landscape evenness index, but a significant positive correlation between water level change and landscape sprawl index.
【学位授予单位】：江西师范大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：P901;P237

【相似文献】