摘要
[目的]探究不同时间尺度下红河流域极端气候变化对植被的影响,对气候变化背景下流域生态系统保护和适应性管理具有重要意义。[方法]基于1982—2022年NDVI数据和38个气象站点的实测日气象数据,使用RClimDex模型计算16个极端气候指数,并运用趋势分析和相关分析探讨NDVI在年、季、月尺度下对极端气候事件的响应特征。[结果]1)红河流域NDVI年平均值为0.68,总体呈显著上升趋势,变化幅度为0.035/(10 a)(p<0.01、R^(2)=0.78);空间上呈“南高北低、西高东低”的分布格局。2)极端高温事件趋多趋强,极端降水指数中仅连续湿润天数以0.42 d/10 a的速率显著下降,流域整体呈暖干化态势。3)极端暖指数的增加对植被生长具有显著的促进作用,极端冷指数的增加对植被生长具有显著的抑制效应,而DTR则表现出短期尺度上对NDVI的正向促进作用和长时间尺度下对NDVI的反向抑制作用;大部分极端降水指数与NDVI在年尺度上呈显著正相关,而在季节和月尺度上多表现为负相关。[结论]不同时间尺度下植被NDVI对极端气候指数的响应存在显著差异。总体来看,气温对植被的动态变化起主导作用,极端气温对植被NDVI变化的贡献率高于极端降水,而植被对极端降水事件表现出良好的适应性。
[Objective]Studying the impact of extreme climate change on vegetation in the Red River basin at different time scales is of great significance for the protection and adaptive management of watershed ecosystems in the context of climate change.[Methods]Based on NDVI data from 1982 to 2022 and daily meteorological data from 38 weather stations,16 extreme climate indices were calculated using the RClimDex model.Trend detection and partial correlation analysis were used to investigate the response characteristics of NDVI to extreme climate events at annual,seasonal,and monthly scales.[Results]1)The annual average NDVI in the Red River basin was 0.68,showing a significant upward trend at a rate of 0.035 per decade(p<0.01,R^(2)=0.78).Spatially,NDVI exhibited a distribution pattern of"high in the south,low in the north,and high in the west,low in the east".2)Extreme high-temperature events increased in both frequency and intensity,while among the extreme precipitation indices,only the consecutive wet days decreased significantly at a rate of 0.42 day per decade,indicating an overall warming and drying trend in the basin.3)The increase in extreme warm indices significantly promoted vegetation growth,while the increase in extreme cold indices had a significant inhibitory effect on vegetation.The diurnal temperature range(DTR)showed a positive correlation with NDVI at a short-term scale and a negative inhibiting effect on NDVI at a long-term scale.Most extreme precipitation indices were significantly positively correlated with NDVI at the annual scale,while they mostly exhibited negative correlations at the seasonal and monthly scales.[Conclusion]There are significant differences in the response of vegetation NDVI to extreme climate indices across different time scales.Overall,temperature plays a dominant role in the dynamic changes of vegetation,with extreme temperature contributing more significantly to NDVI changes than extreme precipitation,while vegetation exhibits good adaptability to extreme precipitation events.
作者
王谦
关颖慧
刘玉国
WANG Qian;GUAN Yinghui;LIU Yuguo(Jianshui Research Station,School of Soil and Water Conservation,Beijing Forestry University,Beijing 100083,China;Key Laboratory of State Forestry Administration on Soil and Water Conservation,Beijing Forestry University,Beijing 100083;Institute of Ecological Protection and Restoration,Chinese Academy of Forestry Sciences,Beijing 100091,China)
出处
《水土保持学报》
北大核心
2025年第3期392-402,共11页
Journal of Soil and Water Conservation
基金
中央级公益性科研院所基本科研业务费专项(CAFYBB2021MA013)
国家自然科学基金项目(42371066)。
