赣江流域植被恢复对水文干旱缓解量化分析OA

Vegetation restoration measures are key interventions for regulating hydrological drought resilience.Understanding its regulatory mechanism is regarded as a theoretical prerequisite for planning such measures.Based on long-term meteoro-logical-hydrological records,land use/land cover data,and geospatial information in Ganjiang River Basin,this study system-atically applied the SWAT model and scenario analysis to clarify the co-evolution patterns of meteorological and hydrological droughts with LUCC change,followed by quantifying the contribution of vegetation restoration to hydrological drought mitiga-tion.The analysis indicates that the basin was dominated by forest and cropland,accounting for 68.8％ and 26.9％ of the area,respectively.Vegetation restoration has been pronounced,indicated by a significant increase in Normalized Difference Vegetation Index(NDVI).The overall meteorological drought in the basin remained stable,with a significant wetting trend only observed in the post-flood season and over long-term scales of more than 9 months.In contrast,hydrological drought has been generally alleviated,with the mitigation effect being particularly pronounced during the flood season.Notably,the fre-quency of abrupt drought-flood alternation from the main flood season to the post-flood season has increased,predominantly characterized by transitions from drought to flood.The SWAT model exhibits satisfactory simulation performance:the Nash-Sutcliffe Efficiency coefficients and coefficients of determination during the calibration and validation periods are greater than 0.63 and 0.65,respectively.Scenario analysis reveals that the increase in NDVI values promotes more uniform runoff distribution from the main flood season to the post-flood season,which constitutes the primary driver behind the alleviation of seasonal hydrological drought.