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草业学报 ›› 2021, Vol. 30 ›› Issue (9): 15-26.DOI: 10.11686/cyxb2020324

• 研究论文 • 上一篇    下一篇

高寒草地生长季/非生长季植被盖度遥感反演

刘佳丽1,2(), 范建容1(), 张茜彧1, 杨超1,2, 徐富宝1,2, 张晓雪3, 梁博3   

  1. 1.中国科学院水利部成都山地灾害与环境研究所,四川 成都 610041
    2.中国科学院大学,北京 100049
    3.西藏自治区水土保持局,西藏 拉萨 850000
  • 收稿日期:2020-07-07 修回日期:2020-11-02 出版日期:2021-08-30 发布日期:2021-08-30
  • 通讯作者: 范建容
  • 作者简介:Corresponding author. E-mail: fjrong@imde.ac.cn
    刘佳丽(1994-),女,湖北孝感人,在读博士。E-mail: liujiali@imde.ac.cn
  • 基金资助:
    第二次青藏高原综合考察研究(2019QZKK0603);中国科学院“西部之光”人才培养引进计划资助

Remote sensing estimation of vegetation cover in alpine grassland in the growing and non-growing seasons

Jia-li LIU1,2(), Jian-rong FAN1(), Xi-yu ZHANG1, Chao YANG1,2, Fu-bao XU1,2, Xiao-xue ZHANG3, Bo LIANG3   

  1. 1.Institute of Mountain Hazards and Environment,Chinese Academy of Sciences,Chengdu 610041,China
    2.University of Chinese Academy of Science,Beijing 100049,China
    3.Water and Soil Conservation Bureau of Tibet Autonomous Region,Lhasa 850000,China
  • Received:2020-07-07 Revised:2020-11-02 Online:2021-08-30 Published:2021-08-30
  • Contact: Jian-rong FAN

摘要:

植被盖度是刻画陆地生态系统植被覆盖的重要生态参量。以当雄县Landsat-8OLI为数据源,从10种常用植被指数中筛选出适合反演高寒草地生长季/非生长季草地植被盖度的植被指数,引入像元三分法确定端元特征值,通过不同植被指数基于像元二分模型反演植被盖度的对比分析,确定适合生长季/非生长季植被盖度最优植被指数,根据反演结果分析了研究区草地生长季/非生长季植被盖度的时空变化特征。结果表明:1)由可见光-近红外波段构建的植被指数适用生长季植被盖度反演,由短波红外构建的植被指数适用于非生长季植被盖度反演。2)基于MSACRI的像元二分模型适合非生长季植被盖度反演,基于NDVI的像元二分模型则最适用于生长季植被盖度的反演。3)研究区草地植被盖度随海拔增加呈现先增加后减少的单峰变化格局,草地集中分布于海拔4300~5100 m处。生长季植被盖度主要集中于20%~80%,非生长季绝大部分的草地盖度小于40%。研究结果可为草地生态系统碳存储、植被生产力、土壤侵蚀、生态水文等研究提供参考依据。

关键词: 生长季/非生长季, 植被盖度, 植被指数, 高寒草地

Abstract:

Vegetation cover is an important ecological parameter for describing vegetation status of terrestrial ecosystems. Using Landsat-8OLI data for Dangxiong County as the data source, the most suitable vegetation index for estimation of vegetation cover in Alpine Grassland in the growing and non-growing seasons was selected from 10 commonly used vegetation indices. A three-pixel linear mixed model was used to estimate the end element values. The optimal vegetation index for inversion of vegetation cover in the growing and non-growing seasons was determined by comparison of results obtained using the different vegetation indices, based on the pixel bisection model. The selected model was then used to analyze the temporal and spatial distribution of vegetation cover in the growing and non-growing seasons. The results showed that: 1) A vegetation index constructed from the visible-near infrared band performed best for the inversion of vegetation cover in the growing season, and an index constructed from the shortwave infrared was suitable for the inversion of vegetation cover in the non-growing season. 2) The modified soil-adjusted corn residue index (MSACRI) pixel dichotomy model was the best model to invert the vegetation cover in the non-growing season, and the normalized difference vegetation index (NDVI) pixel dichotomy model was the best for inversion of the vegetation cover in the growing season. 3) Across a gradient of increasing altitude, the vegetation cover presented a single-peak pattern with the peak at mid-altitude. Grassland was mainly found at 4300-5100 m above sea level. The vegetation cover in the growing season typically ranged from 20% to 80%, while cover in the non-growing season was mostly less than 40%. This research results provides reference data for studies on grassland ecosystem carbon storage, vegetation productivity, soil erosion, and ecological hydrology.

Key words: growing season, non-growing season, vegetation cover, vegetation index, alpine grassland