Status: this preprint is currently under review for the journal HESS.
A high-resolution perspective of extreme rainfall and river flow under extreme climate change in Southeast Asia
Mugni Hadi Hariadi1,2,3,Gerard van der Schrier1,Gert-Jan Steeneveld2,Samuel Sutanto4,Edwin Sutanudjaja5,Dian Nur Ratri3,Ardhasena Sopaheluwakan3,and Albert Klein Tank6Mugni Hadi Hariadi et al.Mugni Hadi Hariadi1,2,3,Gerard van der Schrier1,Gert-Jan Steeneveld2,Samuel Sutanto4,Edwin Sutanudjaja5,Dian Nur Ratri3,Ardhasena Sopaheluwakan3,and Albert Klein Tank6
Received: 10 Jan 2023 – Discussion started: 16 Jan 2023
Abstract. This article provides high-resolution information on the projected changes in annual extreme rainfall and high and low streamflow events over Southeast Asia under extreme climate change. The analysis was performed using the bias-corrected result of the High-resolution Model Intercomparison Project (HighResMIP) multi-model experiment for the period 1971–2050. Eleven rainfall indices were calculated along with streamflow simulation using the PCR-GLOBWB hydrological model. The historical period 1981–2010 and the near-future period 2021–2050 were considered for this analysis. Results indicate that over Indochina, Myanmar faces more challenges in the near future. The east coast of Myanmar will experience more extreme high rainfall conditions, while northern Myanmar will have longer dry spells. Over the Indonesian maritime continent, Sumatra and Java will suffer from the increase in dry spell length of up to 40 %, while the increase of extreme high rainfall will occur over Borneo and mountainous areas in Papua. Based on the streamflow analysis, the impact of climate change is more prominent in a low flow event than in a high flow event. The majority of rivers in the central Mekong catchment, Sumatra, the Malaysian peninsula, Borneo, and Java will experience more extreme low flow events. More extreme dry conditions in the near future are also seen from the increasing probability of future low flow occurrences, which reaches 101 % and 122 % on average over Sumatra and Java, respectively. Finally, the changes in extreme high and low streamflow events are more pronounced in rivers with steep hydrographs, while rivers with shallow hydrographs have a higher risk in the probability of low flow change. Our study highlights the importance of catchment properties in aggregating and/or buffering the impact of extreme climate change.
We utilize the high-resolution CMIP6 on extreme rainfall and extreme streamflow projection over Southeast Asia. This region will experience an increase in both dry and wet extremes in near future. We found a more extreme low flow and high flow, respectively along with the increasing probability of low flow and high flow events. We reveal that the changes in low flow events and their probabilities are not only influenced by extreme dry climates but also by the catchment characteristics.
We utilize the high-resolution CMIP6 on extreme rainfall and extreme streamflow projection over...