干旱区研究 ›› 2021, Vol. 38 ›› Issue (4): 1104-1110.doi: 10.13866/j.azr.2021.04.22

• 植物与植物生理 • 上一篇    下一篇

吐鲁番盆地骆驼刺保护区植被覆盖度时空演变

李梓钰(),陈启慧,黄峰(),郭振天   

  1. 河海大学水文水资源学院,江苏 南京 210098
  • 收稿日期:2021-01-26 修回日期:2021-03-15 出版日期:2021-07-15 发布日期:2021-08-03
  • 通讯作者: 黄峰
  • 作者简介:李梓钰(1997-),女,硕士研究生,研究方向为生态水文. E-mail: 1034677728@qq.com
  • 基金资助:
    国家重点研发计划项目(2017YFC0406101);新疆水专项(2020.E-001.2.4)

Spatiotemporal evolution of vegetation coverage in Alhagi sparsifolia Reserve in Turpan Basin, Xinjiang

LI Ziyu(),CHENG Qihui,HUANG Feng(),GUO Zhentian   

  1. College of Hydrology and Water Resources, Hohai University, Nanjing 210098, Jiangsu, China
  • Received:2021-01-26 Revised:2021-03-15 Online:2021-07-15 Published:2021-08-03
  • Contact: Feng HUANG

摘要:

基于Landsat TM/ETM+/OLI影像数据和无人机影像,通过建立归一化植被指数(normalized difference vegetation index,NDVI)和植被覆盖度关系,计算像元二分模型的参数值,反演1996—2020年吐鲁番骆驼刺保护区的植被覆盖度,再利用一元线性回归分析,研究了吐鲁番骆驼刺保护区历年植被覆盖度演变时空特征。结果表明:25 a来,骆驼刺保护区的植被覆盖度总体呈增加趋势,显著改善区面积占比20.14%,植被覆盖度由3.09%增加至18.30%,主要分布在由西向中部沿白杨河尾闾处和西部、东北部居住用地附近。研究结果可为像元二分模型参数值的确定提供科学参考,为吐鲁番盆地生态环境治理和保护提供科学依据。

关键词: 像元二分模型, NDVI, 植被覆盖度, 无人机遥感, 骆驼刺保护区, 吐鲁番, 新疆

Abstract:

It is of substantial significance for ecological and environmental protection to restore vegetation coverage by returning grazing land to grassland. In this study, the regional normalized difference vegetation index (NDVI) data were extracted from Landsat Thematic Mapper (TM)/ Enhanced Thematic Mapper Plus (ETM+)/Operational Land Imager multi-phase remote sensing images, which were selected from July to September of each year from 1996 to 2020. Meanwhile, Fractional Vegetation Coverage (FVC) was calculated by computing the equation of Excess Green minus Excess Red (ExG-ExR). Additionally, the variables in the equation were based on Unmanned Aerial Vehicle images in the early part of August 2019. The best-fit curve between NDVI and FVC was first established based on the above NDVI and FVC data in the same period. Then, two parameters of the pixel binary model were calculated through the fitted curve between NDVI and FVC: NDVI for the pure bare soil pixels and NDVI for the pure vegetation cover pixels. Then, the pixel binary model was used to retrieve the vegetation coverage of the Alhagi sparsifolia reserve in the Turpan Basin from 1996 to 2020. Finally, linear regression analysis was used to investigate the evolution of vegetation coverage in the A.sparsifolia Reserve in the Turpan Basin throughout the study period. The results showed that vegetation coverage increased in the A.sparsifolia Reserve in the Turpan Basin over the past 25 years. The area of the significant improvement area accounted for 20.14% of the total area of the A. sparsifolia Reserve in the Turpan Basin, and the vegetation coverage of the significant improvement area increased from 3.09% to 18.30% over the past 25 years. A.sparsifolia was primarily distributed from western to central regions in the significant improvement area along the tail of the Baiyang River, which empties into the Aiding Lake, its terminal lake, at the lowest altitude of the A.sparsifolia Reserve. The areas in the west and northeast of the A.sparsifolia Reserve, which were close to residential land located in the south of the Flaming Mountains and east of Tuokesun County, also belonged to the significant improvement area. The results of this research provide a scientific reference for selecting the two parameters of the pixel binary model and a scientific basis for ecological environment management and protection of the Turpan Basin in Xinjiang.

Key words: the pixel binary model, normalized difference vegetation index, fractional vegetation coverage, unmanned aerial vehicle remote sensing, Alhagi sparsifolia Reserve, Turpan, Xinjiang