Recently, the frequent occurrence of droughts has caused a serious impact on vegetation growth and progression. This research is based upon the normalized difference vegetation index (NDVI) from 2001 to 2020. The correlation between the NDVI and standardized precipitation evapotranspiration index (SPEI) at disparate time scales was used to assess the response of vegetation growth to drought in the Yinshanbeilu region. The drought levels of SPEI1, SPEI3, SPEI6, and SPEI12 increased prominently in the eastern region of the country, while the NDVI decreased significantly from east to west in spring, summer, and autumn but was reversed in the winter. The area with an upward trend (33.86%) was slightly lower than that with a downward trend (66.14%). The correlation coefficients between the NDVI and SPEI over the entire year increased with the SPEI timescale. The elevated values were concentrated in the southeastern and western regions of the survey region. Additionally, the best correlation timescales were SPEI6 and SPEI12. Grassland was the most sensitive vegetation type to the SPEI response in the NDVI. The correlation coefficients of NDVI and SPEI1–12 were 0.313, 0.459, 0.422, and 0.406. Both spring and summer were more responsive to SPEI12, whereas autumn and winter were more responsive to SPEI3. The correlation of disparate time scales exhibited complex soil texture features with respect to different seasonal scales, and the soil texture showed a strong response to vegetation in both summer and autumn. Loam, sandy loam, and silty loam all exhibited the highest response to SPEI12, with coefficients of 0.509, 0.474, and 0.403, respectively.

中文翻译：

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内蒙古银山北路不同时间尺度NDVI对SPEI的季节响应

近年来，干旱频发，对植被生长发育造成严重影响。本研究以2001年至2020年的归一化植被指数（NDVI）为基础，利用不同时间尺度的NDVI与标准化降水蒸散指数（SPEI）的相关性来评估阴山北路地区植被生长对干旱的响应。 。 SPEI1、SPEI3、SPEI6、SPEI12的干旱程度在东部地区显着增加，而NDVI在春、夏、秋三季自东向西显着下降，而冬季则相反。呈上升趋势的区域（33.86%）略低于呈下降趋势的区域（66.14%）。全年NDVI与SPEI的相关系数随着SPEI时间尺度的增加而增大。升高值主要集中在调查区的东南部和西部地区。此外，最佳相关时间尺度是 SPEI6 和 SPEI12。草地是对 NDVI 中 SPEI 响应最敏感的植被类型。 NDVI和SPEI1-12的相关系数分别为0.313、0.459、0.422和0.406。春季和夏季对 SPEI12 的反应更敏感，而秋季和冬季对 SPEI3 的反应更敏感。不同时间尺度的相关性在不同季节尺度上表现出复杂的土壤质地特征，并且夏秋季节土壤质地对植被表现出强烈的响应。壤土、砂壤土和粉质壤土对 SPEI12 的响应最高，系数分别为 0.509、0.474 和 0.403。