欢迎访问《草业学报》官方网站,今天是 分享到:

草业学报 ›› 2024, Vol. 33 ›› Issue (10): 28-36.DOI: 10.11686/cyxb2023470

• 研究论文 • 上一篇    下一篇

2001-2020年黄土高原植被生长季干旱的时空分布

刘立靖(), 吴静(), 李纯斌, 常秀红   

  1. 甘肃农业大学资源与环境学院,甘肃 兰州 730070
  • 收稿日期:2023-12-04 修回日期:2024-01-31 出版日期:2024-10-20 发布日期:2024-07-15
  • 通讯作者: 吴静
  • 作者简介:Corresponding author. E-mail: wujing@gsau.edu.cn
    刘立靖(1997-),女,甘肃庄浪人,在读硕士。E-mail: 2540480874@qq.com
  • 基金资助:
    国家自然科学基金(31760693)

Spatial and temporal distributions of drought on the Loess Plateau during the growing seasons of 2001-2020

Li-jing LIU(), Jing WU(), Chun-bin LI, Xiu-hong CHANG   

  1. College of Resources and Environmental Science,Gansu Agricultural University,Lanzhou 730070,China
  • Received:2023-12-04 Revised:2024-01-31 Online:2024-10-20 Published:2024-07-15
  • Contact: Jing WU

摘要:

基于MODIS实际蒸散量(ET)和潜在蒸散量(PET)反演作物缺水指数(CWSI),研究黄土高原生长季干旱时空变化特征,并用CWSI和植被归一化指数(NDVI)进行偏相关分析以探究生长季内最干旱月份对NDVI的影响。结果表明:1)黄土高原生长季CWSI多年平均值为0.777,处于中度干旱状态,空间分布表现为东南部较轻,西北部较严重的特征,且高程在1200~1700 m区域内的干旱程度最高;2)2001-2020年多年生长季CWSI整体呈显著下降趋势,其中2001年干旱程度最高,2018年干旱程度最低;在整个生长季内,黄土高原在4月的干旱程度最高;8月的干旱程度最低。具体表现为:4-10月,干旱等级从重旱过渡到中旱和轻旱,又从轻旱演变成中旱;3)从植被类型角度分析,荒漠、草原的分布区域属于重旱;草甸、栽培植被、灌丛的分布区域属于中旱;针叶林、阔叶林的分布区域属于轻旱,且不同植被类型在植被生长季的CWSI均呈波动下降趋势。研究结果可为黄土高原地区的生态预警和旱灾预估提供科学依据。

关键词: 黄土高原, 生长季, 作物缺水指数, 植被归一化指数, 干旱

Abstract:

Based on MODIS actual evapotranspiration (ET) and potential evapotranspiration (PET) inversion of crop water stress index (CWSI), the spatial and temporal variability of drought during the growing season in the Loess Plateau was investigated, and bias correlation analysis was conducted between the CWSI and the degree of vegetation cover (NDVI) to investigate the influence of the driest month on the NDVI during the growing season. The results showed that: 1) The multi-year average value of CWSI in the growing season of the Loess Plateau was 0.777, which reflected a moderate drought state, and the spatial distribution showed a pattern of lighter drought in the southeast and more severe drought in the northwest, together with greater drought severity in areas with lower elevation of 1200-1700 m. 2) The overall CWSI in the growing season showed a significant decreasing trend across years from 2001 to 2020, with the drought degree being the highest in 2001 and the lowest in 2018. Within the growing season, the Loess Plateau had the highest degree of drought in April; and the lowest degree of drought in August. Specifically, as the growing season progressed, the drought level transitioned from severe drought to moderate drought and light drought, and then from light drought to moderate drought. 3) Analyzed from the perspective of vegetation types, the surveyed areas of desert and grassland were in severe drought; the surveyed areas of meadow, cultivated vegetation, and scrub were in moderate drought; and the surveyed areas of coniferous and broadleaf forests were in light drought, and the CWSI of the different vegetation types showed a fluctuating and decreasing pattern during the vegetation growing season. The study provides a scientific basis for ecological early warning and drought prediction in the Loess Plateau region.

Key words: Loess Plateau, growing season, crop water stress index, vegetation normalization index, drought