基于MODIS数据的喀斯特地区石漠化时空演变特征研究

发布时间：2018-03-10 04:40

本文选题：石漠化　切入点：植被覆盖度　出处：《中国地质大学(北京)》2015年硕士论文　论文类型：学位论文

【摘要】：西南岩溶地区的土地石漠化现象是喀斯特生态系统退化到极端的表现形式,严重制约着当地区域社会经济的健康发展,石漠化问题越来越成为中国岩溶地区生态环境建设的重点和难点,并成为了众多专家学者的研究热点。木文以岩溶地区复杂、分布面积大、类型齐全、石漠化灾害严重的广西壮族自治区为研究对象,通过数学模型和GIS的空间运算,对研究区2004年到2014年间石漠化演变特征进行了分析。研究成果如下:(1)提出石漠化遥感分类的综合指标,并建立了分类指标体系在前人石漠化指标研究的基础上,结合石漠化分级指标选取原则和本文的研究目的,确定了适用于大尺度石漠化遥感监测的分类指标体系,据此把广西喀斯特地区的石漠化类型划分为:重度石漠化、中度石漠化、轻度石漠化、无石漠化。(2)提出了广西地区基于MODIS数据的植被覆盖度(FVC)计算模型。选取植被指数EVI作为基础数据,运用像元二分模型法,构建了适用于广西地区的植被覆盖度(FVC)计算模型。(3)构建了石漠化遥感时空动态模型算法,对研究区2004-2014年石漠化时空演变过程和特征进行了分析。通过石漠化演变方式、转移矩阵、演变速率、演变趋势等指标的计算,表明广西石漠化面积达到了全区总面积的16%,占岩溶面积的50%以上;石漠化在空间上呈现沿东北—西南轴集中分布,西北重、东南轻的宏观格局;2004年-2014年,十年间,石漠化演变涉及面积广,达到50%以上,但植被覆盖度整体呈现增高趋势,石漠化改善面积远大于恶化面积,石漠化得到有效遏制。(4)在FRAGSTATS3.4平台下,选取类型水平和景观水平的景观指数,运用景观空间分析方法对广西喀斯特石漠化空间格局演化特征进行了分析。2004年到2014石漠化的斑块总数和面积总数在减少,发生程度严重的中、重度石漠化类型数量在减少。2004到2014的景观破碎度下降,说明一些对小的石漠化斑块的治理工作取得了良好的效果。
[Abstract]:The phenomenon of rocky desertification in karst areas of southwest China is a manifestation of karst ecosystem degradation to extreme, which seriously restricts the healthy development of local social economy. The problem of rocky desertification has become more and more important and difficult in the construction of ecological environment in karst areas in China, and has become the research hotspot of many experts and scholars. Guangxi Zhuang Autonomous region, which has serious rocky desertification disaster, is studied by mathematical model and spatial operation of GIS. The evolution characteristics of rocky desertification in the study area from 2004 to 2014 are analyzed. The research results are as follows: 1) the comprehensive index of remote sensing classification of rocky desertification is proposed, and the classification index system is established on the basis of previous studies on the index of rocky desertification. Combined with the principle of classification index selection of rocky desertification and the research purpose of this paper, a classification index system suitable for large-scale remote sensing monitoring of rocky desertification is established, according to which the types of rocky desertification in Karst region of Guangxi are classified as severe rocky desertification. Middle rocky desertification, mild rocky desertification and no rocky desertification. (2) A model for calculating vegetation coverage based on MODIS data in Guangxi is proposed. The vegetation index (EVI) is selected as the basic data and the pixel dichotomy model method is used. In this paper, a model of vegetation coverage (FVC3), which is suitable for Guangxi region, is established. The algorithm of remote sensing temporal and spatial dynamic model of rocky desertification is constructed. The process and characteristics of space-time evolution of rocky desertification in the study area from 2004 to 2014 are analyzed. The calculation of transfer matrix, evolution rate and evolution trend shows that the rocky desertification area in Guangxi has reached 16 percent of the total area of the whole area, accounting for more than 50% of the karst area. From 2004 to 2014, the evolution of rocky desertification was extensive, reaching more than 50%, but the vegetation coverage showed an increasing trend, and the improvement area of rocky desertification was much larger than that of deterioration. Rocky desertification was effectively curbed. (4) under the FRAGSTATS3.4 platform, the landscape index of type level and landscape level was selected, The spatial pattern evolution characteristics of karst rocky desertification in Guangxi were analyzed by using landscape spatial analysis method. From 2004 to 2014, the total number of patches and the total area of rocky desertification decreased, and the degree of occurrence was serious. The number of severe rocky desertification decreased from 2004 to 2014, indicating that some small rocky desertification patches had achieved good results.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X171

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