Ecological drought monitoring of Inner Mongolia vegetation growing season based on kernel temperature vegetation drought index (kTVDI).

Ecological drought monitoring is important for regional status assessment and protection of water resources. In this study, we constructed a new ecological drought index, the kernel temperature vegetation drought index (kTVDI), by using the kernel normalized vegetation index (kNDVI) to improve the temperature vegetation drought index (TVDI) in Inner Mongolia. We further analyzed the spatial and temporal distribution of ecological drought in Inner Mongolia during 2000-2022 and the future trend of ecological drought by using segmented linear regression model, Theil-Sen median, Mann-Kendall test, and Hurst index. The results showed that kTVDI performed better in monitoring ecological drought than TVDI. From 2000 to 2022, kTVDI showed a decreasing trend in the growing season in Inner Mongolia, but the change was not significant, and a sudden change occurred in 2016, and the wetting trend after the sudden change was more obvious. During the study period, ecological drought in 23.6% of the areas of Inner Mongolia showed an aggravating trend, and ecological drought was alleviated in 46.5% of the area. In the future, ecological drought would be exacerbated in the eastern part but alleviated in the central and western parts of Inner Mongolia.生态干旱监测对区域生态系统水资源状况评估和保护十分重要。本研究以内蒙古为研究区,使用核归一化植被指数(kNDVI)改进温度植被干旱指数(TVDI),构建了一种新的生态干旱指数——核温度植被干旱指数(kTVDI),基于此,利用分段线性回归模型、Sen趋势分析(Theil-Sen median)、曼-肯德尔检验(Mann-Kendall)和赫斯特指数(Hurst)等方法分析2000—2022年间内蒙古生态干旱的时空分布特征和未来变化趋势。结果表明: 相较于TVDI, kTVDI的生态干旱监测能力更强;2000—2022年间,内蒙古植被生长季kTVDI呈下降趋势,但变化不显著,在2016年发生突变,突变后的湿润趋势更为明显;研究期间,内蒙古23.6%地区的生态干旱呈加剧趋势,46.5%地区的生态干旱缓解;未来,生态干旱在内蒙古东部地区存在加剧、在中西部地区存在缓解的可能。.