Henan Polytechnic University
In order to explore the spatio-temporal response characteristics of vegetation to meteorological drought at different time scales in the Yellow River Basin, this study utilized the Standardized Precipitation Evapotranspiration Index (SPEI) and Normalized Difference Vegetation Index (NDVI) data from 1982 to 2020. Various methods, including pixel-wise linear regression model, Sen''s trend analysis, and Mann-Kendall test, were employed to investigate the spatio-temporal distribution characteristics of meteorological drought and its impact on vegetation in the Yellow River Basin. The results indicate that: (1) From 1982 to 2020, the Yellow River Basin showed an insignificant increasing trend in aridity, with regions exhibiting negative trends in SPEI mainly concentrated in the western region from Longyangxia to Lanzhou, the southern part of the Yellow River Basin, and the surrounding areas of the Hetao Plain. (2) The spatial distribution pattern of average vegetation coverage in the Yellow River Basin demonstrated a decreasing trend from south to north and from southeast to northwest. The proportion of regions with a significant increase in vegetation coverage (61.94%) was greater than those with a significant decrease (5.43%). (3) In most areas of the Yellow River Basin, drought conditions were positively correlated with vegetation status. Regions exhibiting significant positive correlations were mainly concentrated in the northwest and northernmost areas of the Yellow River Basin, indicating that vegetation in these areas was severely affected by drought. (4) Grassland and cultivated land showed the strongest response to drought at a six-month time scale, while forests and unused land were more vulnerable to long-term drought compared to other land types. All four landform types were susceptible to medium- to long-term water shortage, with vegetation in hilly areas being the most affected by drought. The research findings provide valuable scientific evidence for disaster prevention and mitigation as well as ecological and environmental development in the Yellow River Basin.