Drought is a natural disaster that significantly impacts the Earth's ecological environment,especially in arid and semi-arid areas.However,drought at a large watershed scale,which plays an important role in sustai...Drought is a natural disaster that significantly impacts the Earth's ecological environment,especially in arid and semi-arid areas.However,drought at a large watershed scale,which plays an important role in sustainable environmental development,has received limited attention.In this study,we analyzed the spatial and temporal variations in drought in the Yellow River Basin,China from 2002 to 2022 and its driving factors using a vegetation health index(VHI).Results showed that average VHI in the Yellow River Basin from 2002 to 2022 was 0.581,with the most severe drought occurring in summer and autumn.The basin showed a slow decreasing trend in drought during the study period.Regarding spatial distribution of monthly drought frequency and trend of VHI,the mean of the frequency was 13.00%,and 78.00%had a drought frequency of 10.00%–20.00%,with moderate drought generally prevailing.Regarding land use types,forest land,grassland,agricultural land,construction land,water body,and wasteland showed a descending order for the annual average VHI.VHI of each land use type was the lowest in summer and autumn,with pronounced seasonal characteristics.The uneven distribution of drought in the Yellow River Basin was primarily influenced by annual precipitation,solar-induced chlorophyll fluorescence,and relative humidity.VHI effectively quantified drought conditions at a regional scale and proved to be highly applicable in the Yellow River Basin.The results clarify the effectiveness of VHI for drought monitoring in the Yellow River Basin and can provide a reference for drought monitoring across the basin.展开更多
基金funded by the Natural Science Foundation Project of Inner Mongolia Autonomous Region(2023LHMS04013)the Research Program for Higher Education Institutions in Inner Mongolia Autonomous Region(STAQZX202319).
文摘Drought is a natural disaster that significantly impacts the Earth's ecological environment,especially in arid and semi-arid areas.However,drought at a large watershed scale,which plays an important role in sustainable environmental development,has received limited attention.In this study,we analyzed the spatial and temporal variations in drought in the Yellow River Basin,China from 2002 to 2022 and its driving factors using a vegetation health index(VHI).Results showed that average VHI in the Yellow River Basin from 2002 to 2022 was 0.581,with the most severe drought occurring in summer and autumn.The basin showed a slow decreasing trend in drought during the study period.Regarding spatial distribution of monthly drought frequency and trend of VHI,the mean of the frequency was 13.00%,and 78.00%had a drought frequency of 10.00%–20.00%,with moderate drought generally prevailing.Regarding land use types,forest land,grassland,agricultural land,construction land,water body,and wasteland showed a descending order for the annual average VHI.VHI of each land use type was the lowest in summer and autumn,with pronounced seasonal characteristics.The uneven distribution of drought in the Yellow River Basin was primarily influenced by annual precipitation,solar-induced chlorophyll fluorescence,and relative humidity.VHI effectively quantified drought conditions at a regional scale and proved to be highly applicable in the Yellow River Basin.The results clarify the effectiveness of VHI for drought monitoring in the Yellow River Basin and can provide a reference for drought monitoring across the basin.
