| 摘要: |
| 干旱对植被的影响存在滞后和累积效应，探究典型喀斯特区域干旱指数对植被生长的影响，为喀斯特区域植被恢复和生态安全提供数据支撑。本研究基于气象数据和MODIS数据，采用SPEI指数、MK检验和时滞与累积效应分析等方法，分析了典型喀斯特区域贵州省植被NDVI时空演变特征以及干旱指数对植被NDVI时滞与累积效应。研究结果表明:①时间上，NDVI年均值呈显著上升趋势，年际变化率均值为0.049/10a；空间上，99.32%区域的植被呈改善趋势，其中71.25%区域植被呈现出显著改善趋势；地貌上，喀斯特地区的NDVI年均值低于非喀斯特地区，但喀斯特地区的植被改善趋势(0.05/10a)快于非喀斯特区域(0.046/10a)。②SPEI趋势空间差异较显著，SPEI斜率为负的主要分布在岩溶槽谷区域，而峰丛洼地SPEI斜率为正的面积占比达95.19%。③NDVI对干旱指数时滞与累积效应的响应主要表现为0个月滞后和3个月累积(TLA0-3)，集中分布在岩溶槽谷区域；其次是1个月滞后和0个月累积(TLA1-0)效应，主要分布在在峰丛洼地。总体上，研究区的东北部累积效应较为明显，而西南区域的时滞效应较为明显。 |
| 关键词: NDVI SPEI 累积效应 滞后效应 喀斯特 |
| DOI： |
| 投稿时间：2024-09-19修订日期：2025-01-06 |
| 基金项目:广西自然科学(2018JJA150135);广西创新驱动发展专项(AA18118038)；广西高校中青年教师科研基础能力提升项目(2021KY0431) ；广西高等教育本科教学改革工程项目(2024JGA268)； |
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| The response of NDVI in typical karst areas to the time lag and accumulation effects of drought index |
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zhangyali1, Guo jiamin1, Tian Yichao2, Lin junliang2, Bai Xiaomei2
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| (1.Beibu gulf university;2.Beibu Gulf university) |
| Abstract: |
| The impact of drought on vegetation has a lag and cumulative effect. Exploring the impact of drought index on vegetation growth in typical karst areas provides data support for vegetation restoration and ecological security in karst areas. This study is based on meteorological data and MODIS data, using methods such as SPEI index, MK test, and time delay and cumulative effects analysis to analyze the spatiotemporal evolution characteristics of vegetation NDVI in typical karst areas of Guizhou Province, as well as the time delay and cumulative effects of drought index on vegetation NDVI. The research results indicate that: ① the annual average value of NDVI shows a significant upward trend, with an average interannual change rate of 0.049/10a; In terms of space, 99.32% of the vegetation in the area shows an improvement trend, with 71.25% of the vegetation in the area showing a significant improvement trend; Geographically, the annual average NDVI in karst areas is lower than that in non karst areas, but the vegetation improvement trend in karst areas (0.05/10a) is faster than that in non karst areas (0.046/10a). ②The spatial differences in SPEI trends are significant, with negative SPEI slopes mainly distributed in karst trough and valley areas, while the proportion of areas with positive SPEI slopes in peak cluster depressions is 95.19%.③ The response of NDVI to the time delay and accumulation effects of drought index mainly shows 0 month lag and 3 month accumulation (TLA0-3), concentrated in karst valley areas; Next are the 1-month lag and 0 month accumulation (TLA1-0) effects, mainly distributed in peak cluster depressions. Overall, the accumulation effect in the northeast direction of the study area is more significant, while the time lag effect in the southwest region is more pronounced. |
| Key words: NDVI SPEI accumulation effect Lag effect karst |
