Studying the transition from meteorological to ecological drought in the disaster risk framework

A meteorological drought occurs when high atmospheric water demand and low water supply lead to water scarcity. This can develop into an ecological drought, affecting ecosystems through hydraulic failure, carbon limitation, and ultimately plant mortality. The transition from meteorological to ecological drought is a complex process, influenced by the interplay of three fundamental components that are often used in the field of disaster risk management: the characteristics of the drought event itself (hazard), the inherent susceptibility of the ecosystem to drought (vulnerability), and the environmental conditions of the ecosystem (exposure). Specifically, we investigate how multiple water-related variables shape the hazard, how plant functional traits determine ecosystem vulnerability, and how groundwater levels affect the exposure of ecosystems to drought.

To investigate the transition, we integrate eddy covariance observations, plant trait databases, and groundwater level data within the hazard-vulnerability-exposure framework. Using a data-driven approach, we assess the relative importance of these components in driving ecological drought. Our findings are then compared with model simulations to provide a comprehensive understanding of the underlying mechanisms.