Temporal and Spatial Distribution Characteristics of Drought and Its Influence on Vegetation Change in Xilin Gol, China

Abstract

Drought hinders economic and social growth in many areas of China, especially in livestock-dominated Xilin Gol League in Inner Mongolia. Most studies exclusively utilize rainfall to measure drought. To clarify the spatial and temporal distribution characteristics and evolution rules of meteorological drought, monthly observation data from nine meteorological stations in Xilin Gol were used to calculate the (effective drought index, EDI). We studied the spatiotemporal pattern of drought and its influence on vegetation in Xilin Gol using the Mann–Kendall test, (empirical orthogonal function, EOF) decomposition, and quantitative representation. (1) The annual average EDI declined by 0.029/10a, and Xilin Gol experienced an average of 0.5 drought occurrences every year. (2) A normal incidence in Xilin Gol is 67.17–72.65%, and that of severe drought is 0.02–0.99%. (3) Xilin Gol’s drought intensity is mostly concentrated in the central, northeast, and southwest regions, especially southwest and central. (4) The first two principal feature vectors in Xilin Gol contributed 52.75% and 14.38% to the variance. (5) The average (normalized differential vegetation index, NDVI )of desert, typical, and meadow steppe increased, especially in typical steppe (0.034/10a). (6) In Xilin Gol, the NDVI–EDI correlation coefficient ranges from −0.642 to 0.888, with an average of 0.392. Only 1.7% of the areas are adversely linked.

Impacts of Climate and Anthropogenic Disturbances on Vegetation Structure and Functions

“…There are four articles included in this SI that conducted research on the effect of climate or anthropogenic changes on vegetation. Two of them investigate the mechanisms of the effects from the individual perspective [4,5], while the other two show the spatiotemporal pattern of the effects [6,7].…”

“…In Chen et al (2022b) [6], the authors studied the impact of drought on vegetation change in Xilin Gol, China. Using monthly observation data from nine meteorological stations in Xilin Gol, they calculated the effective drought index and studied the spatiotemporal pattern of drought and its influence on vegetation using various statistical methods.…”

“…Lastly, in the study by Wang et al (2022) [9], the authors examined the spatiotemporal characteristics and influencing factors of the seasonal ecosystem water-use efficiency of various vegetation types in Inner Mongolia from 2001 to 2020. The study aimed to reveal the response and adaptation characteristics of different vegetation types within the context of global warming on a regional scale, providing insights into the quantification of the temporal and spatial changes in the water-use efficiency of ecosystems in response to climate change, which is highly significant in light of the increasing visibility of environmental problems caused by global changes.…”