基于哨兵2号卫星影像的建瓯市森林扰动变化监测研究

Research on forest disturbance dynamic monitoring of Jianou City based on Sentinel-2 satellite imagery

为及时有效地监测建瓯市森林扰动情况,以Sentinel-2多光谱影像与土地利用变更数据为数据源,采用扰动指数算法,对2019、2020、2021年建瓯市森林扰动区域进行识别并开展动态监测。结果表明:(1)建瓯市各时期森林扰动程度不尽相同,2020年森林扰动程度最高;(2)在建瓯市森林变化状况方面,2个时段森林扰动等级不变的区域面积占比达到90%以上,而森林进一步受到破坏的地区主要分布于南部、东部乡镇;(3)2019-2020年间森林受破坏较大的乡镇,在2020-2021年间均得到改善,可见建瓯市森林砍伐后的自然恢复或复植补种成效较好;(4)建瓯市森林各变化区分布具有显著的空间集聚性,且演变的方向差异明显。综上所述,建瓯市森林扰动在规模上年际变化差异明显,总体变化趋势向好;在空间上具有自相关性,各时期演变方向差异显著。

In order to timely and effectively monitor the forest disturbance in Jianou City,on basis of Sentinel-2 multispectral imagery and land use change data,the disturbance index algorithm was used to identify and dynamically monitor the forest disturbance areas in Jianou City from 2019 to 2021.The results showed that:(1)The degree of forest disturbance in Jianou City was different in each period,and the forest disturbance degree was the highest in 2020.(2)In terms of forest change conditions in Jianou City,the rate of area that the same forest disturbance level in the two periods were over 90%,and the areas where forests had been damaged were mainly distributed in the southern and eastern townships.(3)Townships with more deforestation between 2019 and 2020 were improved between 2020 and 2021,therefore,the natural restoration or replanting after deforestation had better results in Jianou City.(4)The distribution of forest changes had significant spatial agglomeration in Jianou City,and there were clear differences in the direction of evolution.In conclusion,the inter-annual variation of forest disturbance was obvious in Jianou City,and the overall trend of variation was good.The forest disturbance had the characteristics of spatial auto-correlation,and the evolution direction of spatial was significantly different.