安徽省各生态分区的NDVI年际变化特征及归因分析

Analysis on Characteristics and Attribution of NDVI Interannual Change in Different Ecological Divisions in Anhui Province

基于2000~2019年安徽省域植被NDVI逐年数据和2000、2020年土地覆被数据,采用数理统计和空间叠加分析方法,分析了全省及5个生态区(淮北、江淮、皖西、沿江、皖南)NDVI数据和空间分布的变化特征,利用土地覆被变化指标定量剖析了人类活动(主要为快速城镇化过程)对植被变化的影响机制。结果表明:20年间,全省植被NDVI呈上升趋势的区域整体分布较广、稳定性较好,面积占比为81.5%。皖西和皖南区植被覆被状况改善的面积和强度明显高于其余3个生态区。NDVI呈下降趋势的区域不多,且稳定性较差,主要分布在城市、县乡周边以及沿交通廊道呈现网状辐射。5个生态区中,沿江区植被NDVI呈现下降的斑块最多,波动性最高。城镇化为全省最为主导的土地覆被变化过程,这在很大程度上引发了植被NDVI的极显著下降。而林草封育后植被的持续自然生长可能带来了NDVI的极显著上升。

Based on the annual NDVI data of vegetation in Anhui Province from 2000 to 2019 and the land cover data in 2000 and 2020,the change characteristics of NDVI data and spatial distribution in the whole province and 5 ecological regions(Huaibei,Jianghuai,West Anhui,Yanjiang,South Anhui)were analyzed using mathematical statistics and spatial overlay analysis methods,and the impact mechanism of human activities(Mainly rapid urbanization process)on vegetation change was quantitatively analyzed by using land cover change indicators.The results show that the regions with an increasing NDVI in the province have a wide distribution and good stability,accounting for 81.5%of the total area.The area and intensity of vegetation coverage improvement in West and South Anhui were significantly higher than those in the other 3 ecological regions.There are few regions with a declining trend in NDVI,and the stability is poor.It is mainly distributed around cities,counties and townships and along the traffic corridor,showing a network radiation.Among the 5 ecological regions,the NDVI in Yanjiang shows the most decline in patches and the highest volatility.Urbanization is the most dominant process of land cover change in the province,which has caused a very significant decline in NDVI to a large extent.However,the continuous natural growth of forest and grass enclosure may bring about a very significant increase of NDVI.