Impact of climate change on the severity, duration, and frequency of drought in the Great Salt Lake area in Utah

Climate change has been strongly evidenced to cause temperature rise and associated extreme hydrological events such as floods and droughts, particularly during recent years. Although the characterization of both floods and droughts due to climate change is critical for sustainable water resources management, most previous studies have focused on floods than on droughts. There is an urgent need for understanding the relationship between climate change and drought on a regional to national scale. It is important to understand how climate change would impact the severity, duration, and frequency (SDF) of droughts since the SDF curves are critical for regional water resources management. Uncertainties demand due attention while developing the SDF curves as the risk of water resources management failure might be quite high due to climate change. This study attempts to construct the future SDF curves for the Great Salt Lake region in Utah. For this purpose, a statistical downscaling method is used to generate site-specific climate change projections of Global Climate Models (GCMs) and associate Shared Socioeconomic Pathways (SSPs) from the CMIP6 archive. A representative ensemble of GCMs and SSPs will be generated which is assumed to cover climate variability for a majority of the GCMs and SSPs. The results based on the historical SDF curves suggest that there has been an increasing trend of drought severity in the past few decades. Results from this study are expected to help water managers to prepare for the worst drought scenarios in the future given the uncertainties around the future SDF curves.