Projected Changes in the CORDEX-Central Asia’s Precipitation Extremes Using the NEX-GDDP-CMIP6 Models

In this study, future projections of changes in precipitation extremes over the CORDEX-Central Asia domain were analyzed using high-resolution (0.25° x 0.25°) outputs from NEX-GDDP-CMIP6 models under SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5 scenarios. Initially, 17 models were compared against ERA5 reanalysis data, and the five models with the best statistical performance (i.e., IPSL-CM6A-LR, GFDL-ESM4, MRI-ESM2-0, ACCESS-CM2, and BCC-CSM2-MR) were selected. These models were employed to analyze various precipitation indices, including consecutive dry and wet days, heavy and very heavy precipitation days, maximum of annual maximum precipitation, annual 5-day maximum precipitation, wet and very wet days, and simple daily intensity for the periods of 2026–2050, 2051–2075, and 2076–2100 with respect to the reference period of 1981-2010. The findings indicate an overall decrease in the average number of consecutive dry days across the region. Similarly, a slight average increase in the number of consecutive wet days is expected, which could have significant implications for regional water resource management and agricultural activities. Furthermore, the number of heavy precipitation days is projected to increase on average, highlighting the risk of flooding. These analyses underscore significant changes in precipitation extremes due to future climate change in the CORDEX-Central Asia domain. These findings are critical for shaping regional climate adaptation strategies, offering valuable insights for policymakers in water resource management, agricultural planning, and disaster mitigation. By understanding these projected changes, regional resilience to climate impacts can be enhanced, reducing future risks and fostering sustainable development.

Acknowledgement: This research has been supported by Boğaziçi University Research Fund Grant Number 19367.