摘要
在不同时间尺度上分析植被对干旱的时空响应,量化干旱对植被变化的相对影响,对于因地制宜地开展生态修复和防灾减灾具有重要意义。本文基于2000—2020年陕西省85个气象站的观测数据,计算标准化降水蒸散指数(SPEI),结合归一化植被指数(NDVI),采用趋势分析、偏相关分析以及岭回归分析,研究SPEI和NDVI的时空变化特征及其相关性,量化各季节SPEI对年尺度NDVI变化的相对影响。结果表明:(1)2000—2020年陕西省春季的干旱频率最高,达42.6%,其次是夏季(29.7%),秋季和冬季分别为21.6%和21.9%。陕北地区的干旱频率最高(29.6%),其次为陕南地区(28.7%)和关中地区(27.9%)。全省约89.7%的区域呈现出缓慢湿润化趋势,其中,呈湿润化趋势的面积占比为春季>夏季>秋季>冬季。(2)陕西省NDVI在陕南地区、关中地区和陕北地区的平均值分别为0.89、0.77和0.57,全省约88.0%的区域植被呈显著改善。(3)陕西省约53.2%的区域SPEI和NDVI呈现不显著正相关,6.9%的区域相关性显著,主要分布在陕北地区;呈不显著负相关的区域主要分布于关中地区。(4)春季、夏季、秋季和冬季的SPEI对年尺度NDVI变化的相对影响程度大于50%的区域分别约占全省面积的31.1%、23.7%、0.5%和15.3%。
Analyzing and quantifying the spatiotemporal response of vegetation to drought across different time scales are crucial for ecological restoration and disaster prevention.In this study,the standardized precipitation evaporation index(SPEI)was calculated using meteorological observations from 85 stations in Shaanxi Province from 2000 to 2020.By combining SPEI with the normalized difference vegetation index(NDVI),trend analysis,partial correlation analysis,and ridge regression analysiswere employed to investigate the spatiotemporal variations of SPEI and NDVI,examine the correlation between them,and quantify the relative contribution of seasonal SPEI to annual NDVI changes.From 2000 to 2020,the drought frequency in Shaanxi Province was highest in spring(42.6%),followed by summer(29.7%),autumn(21.6%),and winter(21.9%).Northern Shaanxi had the highest drought level(29.6%),followed by southern Shaanxi(28.7%)and central Shaanxi(27.9%).Approximately 89.7%of Shaanxi Province exhibited an increasing humidity trend,which was most pronounced in spring,followed by summer,autumn,and winter.The average NDVIs for southern Shaanxi,central Shaanxi,and northern Shaanxi were 0.89,0.77 and 0.57,respectively,and approximately 88.0%of Shaanxi Province displayed significant vegetation improvements.Approximately 53.2%of Shaanxi Province exhibited no significant positive correlation between SPEI and NDVI,whereas a significant positive correlationwas only observed in 6.9%of the province,mainly concentrated in northern Shaanxi.Non-significant negative correlations were primarily recorded in central Shaanxi.The areas where the relative impactof SPEI in spring,summer,autumn,and winter on annual NDVI changes exceeded 50%accounted for 31.1%,23.7%,0.5%,and 15.3%of the province,respectively.
作者
宁泽楷
宋赪
张亚军
李奇
李佩
NING Zekai;SONG Cheng;ZHANG Yajun;LI Qi;LI Pei(Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region of the Ministry of Education,School of Water and Environment,Chang’an University,Xi’an 710054,Shaanxi,China;Key Laboratory of Ecological Hydrology and Water Security in Arid Region of the Ministry of Water Resources,Chang’an University,Xi’an 710054,Shaanxi,China;College of Land and Resources,Hebei Agricultural University,Baoding 071001,Hebei,China;Power China Northwest Engineering Corporation Limited,Xi’an 710065,Shaanxi,China)
出处
《干旱区研究》
北大核心
2026年第1期156-166,共11页
Arid Zone Research
基金
陕西省自然科学基础研究一般项目(2025JC-YBMS-295)
陕西省自然科学基础研究计划项目(2021JLM-55)。
关键词
SPEI
NDVI
相关性分析
相对影响系数
Standardized Precipitation Evaporation Index
Normalized Difference Vegetation Index
correlation analysis
relative impact factor
