Vegetation responses to extreme meteorological drought event of 2022 in the Yangtze River Basin
A method for assessing vegetation sensitivity and vulnerability to meteorological droughts was proposed in this study.Standardized indices were developed based on precipitation,evapotranspiration,and solar-induced chlorophyll fluorescence data.The sensitivity of vegetation to meteorological drought was quantified by using Correlation Coefficient(CC),Response Time scale(RT),and Response Sensitivity(RS),while vulnerability was assessed by Duration Response Ratio(DRR)and Intensity Response Ratio(IRR).The results indicated that in the vegetation response assessment for meteorological drought of 2022 in Yangtze River Basin,(1)Low sensitivity(median CC=0.36,0.44;median RS=-1.72,-1.58)was observed in evergreen needleleaf forest and grassland exhibited of upstream region.Whereas,the highest sensitivity(median CC=0.68,median RS=-1.37)was shown in cultivated land,and the sensitivity of(woody)savannas surpassed that of forests(median CC:forests=0.41～0.49,woody savanna=0.64,savanna=0.61;median RS:forests=-1.61～-1.57,woody savanna=-1.44,savanna=-1.40)in the middle and lower reaches.(2)The vulnerability of evergreen needleleaf forest was obviously higher than that of other forests(median DRR:needleleaf forest=1.04,other forests=0.85～0.97;median IRR:needleleaf forest=0.94,other forests:IRR=0.76～0.88).Meteorological drought was found to have a greater impact on grasslands than on(woody)savannas in the middle and lower reaches(median DRR:grassland=1.28,woody savanna=0.74,savanna=0.88;median IRR:grassland=1.24,woody savanna=0.74,savanna=0.80).Low vulnerability was exhibited in cultivated land(median DRR=0.77,IRR=0.72).(3)the Jinsha River basin,with the high average elevation,was identified as high vulnerability hotspot,while the Sichuan Basin and the Han River basin were high sensitivity hotspots due to the aggregated croplands.Therefore,to prevent further degradation and irreversible damage,vegetation monitoring and restoration strategies should be conducted according to various responses of vegetation to meteorological drought.
meteorological droughtsensitivityvulnerabilitydrought responseYangtze River Basin
万方数据
维普
