Arid Zone Research ›› 2022, Vol. 39 ›› Issue (2): 615-624.doi: 10.13866/j.azr.2022.02.28

• Ecology and Environment • Previous Articles     Next Articles

Temporal and spatial variation characteristics and influencial factors of soil moisture in the Xiangride-Qaidam River Basin

CHENG Mengyuan1,2,3(),CAO Guangchao2,3,4(),ZHAO Meiliang1,2,3,DIAO Erlong1,2,3,HE Qixin1,2,3,GAO Siyuan1,2,3,QIU Xunxun1,2,3,CHENG Guo1,2,3   

  1. 1. College of Geographical Science, Qinghai Normal University, Xining 810008, Qinghai, China
    2. Qinghai Province Key Laboratory of Physical Geography and Environmental Process, Xining 810008, Qinghai, China
    3. Key Laboratory of Tibetan Plateau Land Surface Processes and Ecological Conservation, Ministry of Education, Xining 810008, Qinghai, China
    4. Academy of Plateau Science and Sustainability, People’s Government of Qinghai Province & Beijing Normal University, Xining 810008, Qinghai, China
  • Received:2021-07-13 Revised:2021-09-15 Online:2022-03-15 Published:2022-03-30
  • Contact: Guangchao CAO E-mail:chengmengyuan2527@163.com;caoguangchao@126.com

Abstract:

As a key factor of the ecological environment, soil moisture is an important indicator for soil monitoring and changes to the ecological environment. This study is based on MOD11A2 LST and MOD13A2 NDVI data, and used mathematical statistical analysis methods, including the temperature-vegetation dryness index (TVDI), correlation analysis, and regional statistical analysis. The temporal and spatial distribution of humidity characteristics and its influencing factors were analyzed. The average TVDI value in the vegetation growing season of the Xiangride-Qaidam River basin from 2005 to 2020 was 0.61; the maximum value was noted in 2015 (0.64) and the minimum value occurred in 2020 (0.58). The interannual TVDI value slowly decreased over time; however, it did increase in 2015. The drought situation in the study area was unstable, and remained at a drought level for an extended time period. The area corresponding to different soil moisture levels, in descending order, was as follows: drought > extremely arid > normal > humid > extremely humid, accounting for 30.63%, 25.77%, 22.16%, 16.44%, and 5.01% of the total area, respectively. The spatial distribution of TVDI gradually decreased from northwest to southeast, with obvious regional differences. Moreover, the TVDI value had a negative correlation with altitude, decreasing by 0.11 for every 500 m increase in altitude. The TVDI was positively correlated with the average temperature, but had no obvious correlation with precipitation.

Key words: soil moisture, temperature vegetation drought index, correlation analysis, Xiangride-Qaidam River Basin