基于MODIS-归一化植被指数的广东省植被覆盖与土地利用变化研究

基于MODIS-NDVI遥感植被指数，利用像元二分模型进行植被覆盖度提取，结合趋势分析和显著性检验等方法，对2000—2020年间广东省的植被覆盖时空变化特征进行分析，并结合土地利用变化图谱，探究土地利用类型对植被覆盖时空变化的驱动作用。结果表明：(1)2000—2020年，广东省植被覆盖度整体以0.23%/a的变化率呈波动增长趋势，但空间异质性显著，呈现出以珠三角地区为中心向外辐射递增的趋势；(2)广东省多年平均植被覆盖度介于0.7—0.76,以中高和高植被覆盖度为主，低植被覆盖区约占研究区总面积的4.37%。全省以植被改善为主(78.18%),显著和极显著退化区域占全区面积的5.84%,主要集中分布在珠三角、粤东沿海以及粤西沿海等地区；(3)研究区以耕地与林地的图谱单元互换为主要土地利用变化特征，而城乡、工矿、居民用地在耕地和林地的占用和补充过程中起了重要的作用，反映出城乡建设过程中对耕地和林地的大量占用；植被覆盖变化与土地利用变化存在响应联系，且各土地利用类型对植被覆盖度的贡献各异；向城乡、工矿、居民用地转化的图谱与植被显著和极显著退化区高度重合，说明耕地和林地向城乡、工矿、居民...

Study on vegetation coverage and land-use change of Guangdong Province based on MODIS-NDVI

In the National Strategy of the Guangdong-Hong Kong-Macao Greater Bay Area, Guangdong Province assumed the function of the ecological protection barrier, and vegetation played an irreplaceable role in regional ecological security and sustainable development as an important regional ecological barrier. It was significant to study the change of fractional vegetation coverage (FVC) in Guangdong Province and its response to land-use change. Based on the MODIS-NDVI remote sensing index from 2000 to 2020, the study used dimidiate pixel model to extract FVC, trend analysis and significance test were used to analyze the temporal and spatial characteristics of FVC and to clarify driving forces of land-use change, which was expected to provide theoretical support and scientific basis for the construction of ecological security pattern and sustainable development decision-making in Guangdong Province. Results showed that (1) the FVC presented a volatility increasing trend with the change rate of 0.23% per year from 2000 to 2020. However, the spatial heterogeneity of FVC dynamic was significant, showing a center of the Pearl River Delta with an increasing trend of outward radiation. (2) The annual average vegetation coverage in Guangdong Province ranged from 0.7 to 0.76, which was dominated by the medium to high and high FVC types, while the areas of low FVC only accounted for about 4.37% of the study area, it was closely related to the regional differences in the topography, land-use types, urbanization process and economic development level of Guangdong Province. The FVC improved areas occupied 78.18% of the study area, significant and very significant degenerated areas accounted for 5.84% of the region which were concentrated in the Pearl River Delta, the east coast and the west coast of Guangdong Province. (3) The major characteristics of land-use change were swaps between the geo-spectrum unit of arable land and forest land, and urban-rural construction land played an important role in the occupation and replenishment of arable land and forest land, which reflected the massive occupation of arable land and forest land in the process of urban and rural construction. There was a response link between FVC change and land-use change, and the contribution of each land-use type to vegetation coverage varied. The map of transformation to urban-rural construction land highly overlapped with the degenerated areas of FVC, which meant the conversion of arable land and forest land to urban-rural construction land was the main reason for the degradation of FVC, most notably in the Pearl River Delta.