Propagation process‐based agricultural drought typology and its copula‐based risk

Abstract

Determining the risks associated with different drought event types can be beneficial for related scientific research and management strategies. In this study, we proposed an agricultural drought event pair and typology based on the governing drought propagation processes in the Yellow River basin at the catchment scale. In total, seven agricultural drought event pairs were distinguished, namely single meteorological drought event pair (MDonly), single soil moisture drought event pair (SDonly), single agricultural drought event pair (ADonly), soil moisture and meteorological drought event pair (SDMD), agricultural and meteorological drought event pair (ADMD), agricultural and soil moisture drought event pair (ADSD) and agricultural, soil moisture and meteorological drought event pair (ASMD). The SDMD and ADMD events had the highest copula‐based risk probabilities with the shortest joint return periods. Six agricultural drought types were distinguished in this study, namely classical rainfall deficit, rain‐to‐snow‐season, wet‐to‐dry‐season, cold snow season, warm snow season and composite drought events. The classical rainfall deficit, wet‐to‐dry season and composite drought events were the major agricultural drought types in the Yellow River basin. The agricultural drought typology results of the present study provide a comprehensive understanding of drought propagation and improvement of drought forecasting and management.