Application of temperature vegetation dryness index for drought monitoring in Mongolian Plateau

Yao Kang; En-Liang Guo; Yong-Fang Wang; Yu-Long Bao; Yu-Hai Bao; Ren-Mandula Na

doi:10.13287/j.1001-9332.202107.018

Application of temperature vegetation dryness index for drought monitoring in Mongolian Plateau

Ying Yong Sheng Tai Xue Bao. 2021 Jul;32(7):2534-2544. doi: 10.13287/j.1001-9332.202107.018.

Authors

Yao Kang^{1

2}, En-Liang Guo^{1

2

3}, Yong-Fang Wang^{1

2}, Yu-Long Bao^{1

2}, Yu-Hai Bao^{1

4}, Ren-Mandula Na^{1

2}

Affiliations

¹ College of Geographical Science, Inner Mongolia Normal University, Hohhot 010022, China.
² Inner Mongolia Key Laboratory of Disaster and Ecological Security on the Mongolian Plateau, Hohhot 010022, China.
³ Lanzhou Institute of Arid Meteorology, China Meteoro-logical Administration, Lanzhou 730020, China.
⁴ Key Laboratory of Remote Sensing and Geographic Information Systems, Inner Mongolia Normal University, Hohhot 010022, China.

PMID: 34313072
DOI: 10.13287/j.1001-9332.202107.018

Abstract
in English, Chinese

Taking the Mongolian Plateau as the study area, the MODIS normalized difference vegetation index (NDVI) and the land surface temperature (LST) in the growing season from 2000 to 2019 were used to construct the NDVI-LST feature space, and based on which the temperature vege-tation dryness index (TVDI) of the Mongolian Plateau was calculated. We used Theil-Sen Median trend analysis, Mann-Kendall test, and Hurst index method to analyze the spatial and temporal varia-tions and future trends of TVDI on the Mongolian Plateau. Furthermore, we examined the relationship between meteorological factors and TVDI on the Mongolian Plateau using partial correlation analysis. The results showed that the TVDI of the Mongolian Plateau during 2000-2019 showed an increasing trend with a rate of 0.0001·a^-1, indicating that the Mongolian Plateau's drought condition became heavier slightly in the last 20 years. The drought condition in meadow steppe and typical steppe gradually decreased, and that in desert steppe and alpine grassland was increased. The average Hurst index of TVDI in the growing season was 0.45, and the area with TVDI less than 0.5 accounted for 71.5% of the total area, which indicated that the TVDI during 2000-2019 in most areas turned opposite to the past. In the future, the drought condition in the central desert steppe area and the eastern meadow steppe area might increase, and that in most of the typical steppe and the desert steppe in Inner Mongolia tended to decrease. The drought change in the alpine grassland area was uncertain. There was a significant positive correlation between the TVDI and temperature in 33.6% area of the Mongolian Plateau and a significant negative correlation between the TVDI and precipitation in 34.8% of the area. Moreover, the meteorological factors heavily affected the typical steppe.

以蒙古高原为研究区,选择2000—2019年植物生长季的MODIS归一化植被指数(NDVI)和陆地表面温度(LST)构建NDVI-LST特征空间,由该特征空间计算蒙古高原温度植被干旱指数(TVDI);利用Theil-Sen Median趋势分析、Mann-Kendall检验及Hurst指数方法分析蒙古高原TVDI的时空变化特征和未来的变化趋势,利用偏相关分析法探究气象因子与蒙古高原TVDI之间的关系。结果表明: 2000—2019年,蒙古高原TVDI以0.0001·a^-1呈增大趋势,期间,蒙古高原的干旱情况小幅加重,其中,草甸草原和典型草原干旱情况逐渐减轻,而荒漠草原和高山草地干旱情况加重。蒙古高原TVDI的Hurst指数均值为0.45,小于0.5的地区面积占比为71.5%,说明大部分地区2000—2019年的TVDI变化趋势与过去相反。中部的荒漠草原地区和东部的草甸草原地区未来干旱情况可能加重;典型草原的大部分地区以及内蒙古境内的荒漠草原未来干旱可能减轻;高山草地地区的干旱变化无法确定。蒙古高原有33.6%的地区TVDI与气温呈显著正相关,34.8%的地区TVDI与降水量呈显著负相关,其中,典型草原受气象因子的影响最显著。.

Keywords: MODIS; Mongolian Plateau; drought monitoring; temperature vegetation drought index.

MeSH terms

China
Droughts*
Grassland
Meteorological Concepts*
Seasons
Temperature

Abstract in English, Chinese

MeSH terms

Abstract
in English, Chinese