长江流域资源与环境 >> 2024, Vol. 33 >> Issue (12): 2619-2631.doi: 10.11870/cjlyzyyhj202412006

• 自然资源 • 上一篇    下一篇

基于多源遥感数据的长江中下游植被时空演变及其对干旱的响应

徐瑞皓1,赵安周1*,李子洋1,边蕊1,朱秀芳2   

  1. (1. 河北工程大学矿业与测绘工程学院,河北 邯郸 056038;2. 北京师范大学地理科学学部遥感科学与工程研究院,北京 100875)
  • 出版日期:2024-12-20 发布日期:2024-12-27

Spatial and Temporal Evolution of Vegetation and Response to Droughts in the Middle and Lower Reaches of the Yangtze River based on Multi-source Remote Sensing Data

 XU Rui-hao1, ZHAO An-zhou1, LI Zi-yang1, BIAN Rui1, ZHU Xiu-fang2   

  1. (1. School of Mining and Geomatics Engineering, Hebei University of Engineering, Handan 056038, China; 2. Institute of Remote Sensing Science and Engineering, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China)
  • Online:2024-12-20 Published:2024-12-27

摘要:  基于归一化植被指数(Normalized Difference Vegetation Index, NDVI)、增强植被指数(Enhanced Vegetation Index, EVI)、总初级生产力(Gross Primary Productivity, GPP)以及日光诱导叶绿素荧光(Solar-Induced Chlorophyll Fluorescence, SIF)反演的GOSIF(Global Orbiting Carbon Observatory-2 Solar-Induced Chlorophyll Fluorescence)产品,采用趋势分析法分析了2000~2021年长江中下游流域植被时空演变,在此基础上,结合标准化降水蒸散指数(Standardized Precipitation Evapotranspiration Index, SPEI)进一步分析了植被在干旱状态下的响应情况。得出如下主要结论:(1)时间上,2000~2021年长江中下游流域年NDVI、EVI、GOSIF和GPP均值整体呈显著上升趋势,其增加速率分别为0.002 9 a-1、0.002 4 a-1、0.001 8 W·m-2·μm-1·sr-1·a-1和8.327 4 gC·m-2·a-1(P<0.05);月NDVI、EVI、GOSIF和GPP呈现明显的年内变化特征,其最大值出现在每年的7或8月;(2)空间上,长江中下游流域NDVI、EVI、GOSIF和GPP的高值区主要分布在湖南省西南部、湖北省西部以及江西省等地,低值区主要分布在流域东部的上海、江苏以及浙江等地;流域大部分地区的NDVI、EVI、GOSIF和GPP呈显著上升的趋势,呈显著下降趋势的面积占比仅为3.00%、3.25%、2.19%和1.77%(P<0.05),主要分布在流域中部以及东部的上海等城市周边;(3)随着干旱严重程度的增加(轻旱—特旱),研究区4~9月NDVI、EVI、GOSIF和GPP变化率的均值的下降幅度均呈现增加的趋势,NDVI、EVI、GOSIF和GPP分别由轻旱状态的-2.45%、-3.87%、-4.77%和0.58%下降到特旱状态的-7.26%、-8.57%、-12.59%和-7.87%。不同干旱等级下GOSIF变化率4~9月的均值下降幅度均高于NDVI、EVI和GPP,表明GOSIF对干旱的响应更为敏感。

Abstract: This study analyzed the spatial and temporal evolution of vegetation cover in the middle and lower reaches of the Yangtze River Basin from 2000 to 2021. The data used included Normalised Difference Vegetation Index (NDVI), Enhanced Vegetation Index (EVI), Gross Primary Productivity (GPP) and Global Orbiting Carbon Observatory-2 Solar-Induced Chlorophyll Fluorescence (GOSIF) products inverted from Solar Induced Chlorophyll Fluorescence (SIF). The response of vegetation cover under drought conditions was further analysed by combining with the Standardized Precipitation Evapotranspiration Index (SPEI). The main conclusions were as follows: (1) Temporally, the average annual NDVI, EVI, GOSIF and GPP in the study area showed an overall significant increasing trend, with the increasing rates of 0.002 9 a-1, 0.002 4 a-1, 0.001 8 W·m-2·μm-1·sr-1·a-1 and 8.327 4 gC·m-2 ·a-1 (P<0.05); The monthly NDVI, EVI, GOSIF and GPP showed obvious intra-annual variations, with their maximum values occurring in July or August each year. (2) Spatially, NDVI, EVI, GOSIF and GPP in the study area showed a similar spatial distribution pattern, with the high-value areas mainly distributed in the southwestern part of Hunan Province, the western part of Hubei Province and Jiangxi Province, and the low value areas mainly distributed in the eastern part of the basin, such as Shanghai, Jiangsu, and Zhejiang. The percentage of areas with significantly decreasing trends were only 3.00%, 3.25%, 2.19% and 1.00% (P<0.05). (3) As the severity of drought increases (from mild to severe drought), the average decrease in the change rates of NDVI, EVI, GOSIF, and GPP from April to September showed an increasing trend. NDVI, EVI, GOSIF and GPP decreased from -2.45%, -3.87%, -4.77% and 0.58% in mild drought to -7.26%, -8.57%, -12.59% and -7.87% in the severe drought, respectively. The average values of GOSIF rate of change from April to September under different drought levels demonstrated a greater decrease than those of NDVI, EVI and GPP, indicating that the response of GOSIF to drought events was more sensitive.

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