| Popis: |
Drought is typically induced by the extreme water deficit stress that cascades through the atmosphere, hydrosphere, and biosphere. However, identifying individual cascade connections remains challenging due to the nonlinear interactive loops within drought cascades initiated by numerous physical elements, which hinder the emergent patterns of droughts cascade from being explored further.In this study, we establish a statistical framework for characterizing the dynamic space-time behaviour of droughts to track the droughts cascade. We investigate four typical droughts: precipitation (PCP), evapotranspiration (ET), Runoff, and root-zone soil moisture (SM) throughout Central Asia, the typical arid and semi-arid area of the world. Then, this method extracts 15 emergent patterns of droughts cascading corresponding to the different temporal orders. Moreover, the 15 emergent patterns of droughts cascade are categorized further as two-phase, three-phase, and four-phase drought cascading patterns in keeping with the appearance of hydrological parameters.The result shows the highest occurrence in the four-phase cascading pattern, manifesting that the drought in PCP, ET, Runoff, and SM are expected predominantly to occur consecutively across the study area. Additionally, we find that four variations coefficients of duration, intensity, severity, and area reveal a positive linear relationship during cascading processes. Furthermore, the distribution range and magnitude of four metrics (duration, intensity, severity, and area) of PCP droughts increase with the rising of phase number in all cascading patterns.Traits of the drought cascade provide another perspective for the drought early-warning and impact forecast in Central Asia, which could support the decision-making on drought mitigation in the arid region under exacerbated water deficit stress from global warming.Keywords: group behaviour of droughts, cross-temporospatial scale, arid region, water management |
