Impacts of biogeochemical processes on hydrological extremes under future SSP585 scenario over East Asia

This study assesses future extreme hydrological conditions in East Asia based on four Global Circulation Models (GCMs) from Coupled Model Intercomparison Project Phase 6 with biogeochemistry (CMIP6-BGC), which provides layers of vegetation and soil to estimate carbon and nitrogen cycle. We estimate the frequency and severity of extreme dry and wet conditions based on runoff using the threshold level method under Shared Socioeconomic Pathway and Representative Concentration Pathway (SSP-RCP) 585 scenarios. The differences in extremes between “standard”, which does not consider the detailed biogeochemical processes, and the “BGC” simulations are estimated to quantify the impacts of biogeochemical processes on the hydrological extremes. This study shows that the “standard” case is predicted to be more severe and pronged in intensity and duration of extremes in the future than that of the “BGC” case. For example, the duration of extreme dry and wet conditions in the “BGC” case shows less duration, about 21% and 12%, respectively, in the future than in the “standard” case in three GCMs ensemble. We demonstrate that the effects of the biogeochemical process should be considered to project future extremes because these extremes could be overestimated in “standard” simulations.

 

Acknowledgements

This work was supported by the Basic Science Research Program (2020R1A2C2007670) and the Framework of International Cooperation Program (2021K2A9A2A06038429) through the National Research Foundation of Korea (NRF).