Dynamic assessment of the impact of compound dry-hot conditions on global terrestrial water storage

Precipitation and temperature are critical factors influencing terrestrial water storage (TWS) can lead to unexpected TWS losses when compounded by dryness and high temperatures. Yet, a dynamic assessment of the individual and combined effects of these conditions on TWS is lacking. This study proposes a framework to assess TWS loss driven by compound dry-hot conditions (CDHC) and dynamically evaluates risk probabilities and thresholds for 2003–2012 and 2013–2022. Results showed that CDHC exert a greater impact on TWS than dry or hot conditions alone. The risk probabilities of global TWS loss are higher in the late period than in the early period, with risk probabilities for light and extreme levels increasing by approximately 9–11 % and 2–7 %, respectively. Although the resilience of water resource systems to CDHC has increased in some regions, it still shows a decreasing trend on a global scale. The decrease in the resilience to TWS in major hyperarid areas is primarily influenced by temperature, whereas that in arid areas is primarily affected by precipitation. These distinct patterns may be the primary factors contributing to the exacerbation of global TWS loss. This study provides a novel approach for the dynamic assessment of global TWS under CDHC. The research findings offer valuable insights for decision-makers developing adaptive strategies to mitigate future CDHC challenges.