Quantitative assessment of vegetation drought vulnerability based on multi-weighted averaging of multiple meteorological drought indices and vegetation indices

Vegetation is closely related to the variability of various meteorological factors. Due to the spatiotemporally complex relationship between vegetation and meteorological drought, the assessment of vegetation drought vulnerability remains challenging. This study focuses on the Korean Peninsula and uses four drought indices that can account for different causes of meteorological drought and three representative vegetation indices. A copula-based bivariate joint probability model is constructed between meteorological drought indices and vegetation indices, taking into account the propagation time and delay time from meteorological drought to vegetation drought. From this, the vegetation drought vulnerability is calculated for each combination of meteorological drought index and vegetation index. The spatiotemporal vegetation drought vulnerability of the Korean Peninsula is quantitatively assessed by weighting the vulnerability for each combination based on the correlation strength. The results showed that while vulnerability to each combination was largely consistent, there were meteorological drought indices and vegetation indices that were dominant in certain seasons. Our research can be used as a tool to provide a basis for understanding and responding to the risk of meteorological drought on vegetation.