The time lag accumulation effect of vegetation growth and water and heat in the Han River Basin
Purposes—To study the time lag accumulation effect of vegetation growth on tempera-ture and precipitation in the Han River Basin in the context of global warming for addressing the eco-logical environment construction of the basin.Methods—Based on MODIS NDVI monthly data and monthly average temperature and precipitation data from 2001 to 2020,the differences in NDVI(Nor-malized Difference Vegetation Index)changes during the growth season of different ecological zones and vegetation and their responses to temperature and precipitation are analyzed through correlation and time lag accumulation effect.Results and Conclusions—(1)The NDVI of the Han River Basin shows a fluctuating upward trend during the growth season,with an average of 0.7.The average cor-relation coefficients between NDVI and the temperature and precipitation during the growth season in the Han River Basin are 0.263 and 0.223,respectively.The areas with positive correlation are mostly distributed in ecological function conservation areas and the areas with dense vegetation in mountain-ous and hilly areas,while the areas with negative correlation are mostly distributed in the zones where vegetation are cultivated and planted in plains and basins and the production areas and living quarters of human beings in various cities.(2)During the Han River Basin growing season,NDVI and temper-ature and precipitation have obvious time lag accumulation effect,the vegetation area under the influ-ence of 0-month lag of 1-month accumulation and 3-month lag of 3-month accumulation is more than 50％.The time lag accumulation effect of temperature decreases from the middle to the east and west sides,while precipitation significantly increases from west to east.The time lag accumulation effect of temperature has a greater promoting effect on vegetation coverage than a restraining effect,while pre-cipitation has the opposite effect.(3)The negative correlation between six types of vegetation and the accumulation of temperature and precipitation time lag has weakened.Except for coniferous and broad-leaved forests,the temperature has the greatest impact on the other types of vegetation cover-age when accumulated for 6 months with a lag of 3 months,and low vegetation coverage having the highest response degree.Precipitation has the greatest impact on six types of vegetation coverage when accumulated for 3 months with a lag of 2 months.The average maximum correlation coefficient of precipitation on six types of vegetation is grassland＞meadow＞shrub＞cultivated vegetation＞coniferous forest＞broad-leaved forest.
Han River BasinNDVI(Normalized Difference Vegetation Index)vegetation typeecological partitiontime lag accumulation effect
万方数据
维普
