摘要
伴随着珠三角社会经济和人口密度的快速增长及城镇不断扩张,导致局部地区植被生境不断缩减,因此准确估计植被覆盖度、动态监测珠三角植被的分布格局和时空变化特征,对珠三角的生态安全至关重要。本研究在Google Earth Engine调用Landsat数据集,采用影像中值合成的方式获取研究区高质量无云影像,分别合成珠三角2000、2005、2010、2015和2020年5个时期的影像,保证植被覆盖度反演基础数据源的科学合理性;选择基于NDVI的像元二分法分别估测出珠三角5个时期的植被覆盖度,利用变异系数分析植被覆盖度变化的波动性,选用Slope趋势分析来探究植被覆盖度变化的时空变化特征,采用Hurst指数预测研究区植被覆盖度未来的发展趋势,系统地反映出珠三角地区植被覆盖度时空变化情况。本数据集通过高分辨率影像进行精度验证,精度为0.90,可为珠三角植被覆盖度分布格局和时空变化等方面的研究提供基础数据支撑。
With the rapid growth of social economy and the expansion of cities and towns,coupled with increasing population density in the Pearl River Delta,vegetation habitats in some areas have been continuously reduced.Therefore,it is crucial to accurately estimate vegetation coverage and dynamically monitor the distribution patterns and temporal-spatial changes in vegetation in the Pearl River Delta for the sake of its ecological security.In this study,we utilized the Landsat dataset through Google Earth Engine to acquire high-quality cloud-free images in the study area.By means of median image synthesis,we synthesized the images of the Pearl River Delta in 2000,2005,2010,2015 and 2020,respectively.To ensure the scientific rationality of the basic data source of FVC inversion,we selected the pixel dichotomy method based on NDVI to estimate the FVC in the five periods of the Pearl River Delta,and used the variation coefficient to analyze the fluctuation of FVC change in the five periods of the Pearl River Delta.Moreover,and we adopted the Slope trend analysis to explore the spatial-temporal characteristics of FVC changes.The Hurst index was employed to predict the future development trends of vegetation coverage in the study area,offering a comprehensive representation of the temporal and spatial changes of vegetation coverage in the Pearl River Delta region.The precision of this dataset was validated against high-resolution images with an accuracy of 0.90,which can provide fundamental data support for the research on the distribution patterns and spatio-temporal changes of vegetation coverage in the Pearl River Delta.
作者
沈明潭
谭炳香
侯瑞霞
黄逸飞
SHEN Mingtan;TAN Bingxiang;HOU Ruixia;HUANG Yifei(Research Institute of Forest Resources Information Techniques,Chinese Academy of Forestry,Beijing 100091,P.R.China)
基金
广东省林业局“珠三角森林城市群质量提升关键技术研究”(2021KJCX009)。
关键词
植被覆盖度
时空变化
珠三角
fraction vegetation cover
space-time change
Pearl River Delta
