基于LandTrendr算法的广东省1990—2020年森林干扰与森林恢复的动态变化分析

Dynamic Change Analysis of Forest Disturbance and Forest Recovery in Guangdong Province From 1990 to 2020 Using the LandTrendr Algorithm

  • 摘要: 为准确掌握广东省森林干扰与森林恢复的动态特征,文章基于谷歌地球引擎(Google Earth Engine, GEE)云平台构建Landsat长时序年度无云地表反射率影像集,采用LandTrendr(Landsat-based detection of Trends in Disturbance and Recovery)算法提取广东省1990—2020年森林干扰与森林恢复的时空分布特征,并分析其演变的驱动因素,比较不同森林类型的干扰与恢复特征。结果表明:(1)1990—2020年,广东省的森林干扰总面积约为1.35×104 km2,集中分布在广东省西部、东部和中部小范围地区,干扰面积最大的3个城市分别为韶关、梅州、清远市;森林恢复总面积约为1.91×104 km2,集中分布在广东省北部和西部地区,恢复面积最大的3个城市分别为韶关、清远、肇庆市。(2)广东省森林干扰与森林恢复均集中发生在海拔小于等于600 m的地区,高海拔地区的森林面积较为稳定;广东省森林干扰集中发生在坡度小于等于25°的地区,森林恢复集中发生在坡度小于等于35°的地区。(3)广东省森林干扰在1996年后发生较为频繁,其中2011年的森林干扰面积最大;森林恢复主要集中在2001—2016年,其中2012年的森林恢复面积最大。(4)广东省的森林干扰与森林恢复主要受雨雪冰冻灾害、台风、病虫害等自然因素以及森林火灾、城市化、采伐、林业政策等人为因素的综合影响,其中雨雪冰冻灾害对广东省北部地区的常绿针叶林的影响较大,但该类型的森林恢复也较快。

     

    Abstract: In order to accurately understand the dynamic characteristics of forest disturbance and forest recovery in Guangdong Province, a Landsat long time-series annual cloud-free surface reflectance dataset is established based on the GEE cloud platform. Then, the dataset is combined with the LandTrendr (Landsat-based detection of Trends in Disturbance and Recovery) algorithm to explore the characteristics of the spatial and temporal distribution of forest disturbances and forest restoration in Guangdong Province from 1990 to 2020. Finally, the driving factors of forest evolution and the contrast of the disturbance and recovery characteristics of different forest types are analyzed. The results indicated that: (1)From 1990 to 2020, the total area of forest disturbance in Guangdong Province is 1.35×104 km2, concentrated in the western, eastern, and small areas of central regions. The three cities with the largest forest disturbance area are Shaoguan, Meizhou, and Qingyuan. The total area of forest recovery is 1.91×104 km2, concentrated in the northern and western regions. The three cities with the largest forest recovery area are Shaoguan, Qingyuan, and Zhaoqing. (2)Forest disturbance and forest recovery in Guangdong Province are concentrated in areas less than or equal to 600 m, and the area of forest is relatively stable in high-altitude areas. Forest disturbance in Guangdong Province is concentrated in slopes less than or equal to 25°, while forest recovery is concentrated in slopes less than or equal to 35°. (3)Forest disturbance in Guangdong Province occurred more frequently after 1996, with the largest disturbance area occurring in 2011. Forest recovery in Guangdong Province occurred more frequently from 2001 to 2016, with the largest forest recovery area in 2012. (4)Forest disturbance and forest recovery in Guangdong Province are mainly affected by natural factors (rain, snow, and freezing disasters, typhoons, and insect pests) and human factors (forest fire, urbanization, cutting, and forestry policies). The impact of rain, snow, and freezing disasters on evergreen needle-leaved forests is significant, and this type of forest recovers quickly.

     

/

返回文章
返回