摘要
Abstract
To explore the response mechanism of vegetation start of the growing season(SOS)in the three Northeastern Provinces to extreme temperature events,this study utilized the MODIS NDVI dataset and remote sensing data such as ERA5-Land,and employed the dynamic threshold method to extract the vegetation SOS of this area from 2001 to 2020.Based on the meteorological data from 1981 to 2020,the temperature threshold was determined using the percentile threshold method,and extreme temperature events from 2001 to 2020 were extracted.The Theil-Sen trend analysis method and Mann-Kendall test method were combined to investigate the changes in the vegetation SOS in the three northeastern provinces.Furthermore,Pearson correlation analysis was conducted to explore the relationship between the vegetation SOS and extreme temperature events.The results showed that the vegetation SOS in the study area was mostly concentrated in the period from day 100 to day 130 from 2001 to 2020,with an overall change rate of-0.25 d/a,indicating an advancing trend.The vegetation SOS was generally negatively correlated with extreme high-temperature indicators,and the response to extreme high-temperature events in March and April was more significant.However,the correlation with extreme low-temperature indicators was relatively ambiguous.In summary,an increase in the frequency and intensity of extreme high-temperature events will cause the vegetation SOS in the study area to advance.The response of the vegetation SOS in the study area to extreme low-temperature events is more complex.关键词
植被春季物候/归一化植被指数/极端温度/气候变化/遥感Key words
vegetation start of the growing season/normalized difference vegetation index/extreme temperature/climate change/remote sensing分类
资源环境
