Projection of Compound Dry-Wet Spells in North America at Different Global Warming Levels
Abstract
Analyzing hydroclimatic extreme events in isolation without considering the dependencies between drivers and/or hazards can lead to an underestimation of the corresponding risks. Recent disasters have highlighted the potential for increases in high-impact temporally compound drought and flood hazards. Such transitions pose a substantial risk for water management practices such as reservoir operation, as a trade-off should be considered between short-term flood control and long-term water storage. This study analyzes the projected compound dry-wet spells across North America. We address the following research questions (1) how the characteristics of compound dry-wet spells will change in the future at different warming levels, (2) where are the hotspots of compound dry-wet spells in North America, (3) whether individual and compound spells form spatially clustered patterns, and (4) how reliable are the indices that characterize the spatiotemporal changes in compound events. Precipitation, soil moisture and runoff data from the 50-member CanRCM4 large ensemble are considered to derive three dry-wet indices representing meteorological, hydrological, and agricultural floods and droughts. Additionally, we integrate bivariate and trivariate indices to investigate the overall dry-wet spells. The frequency, duration, transition time, intensity of transition, aggregation index, Moran's I, and spatial dry-wet contribution index are considered for characterizing compound dry-wet spells. Overall, the frequency and intensity of individual and compound spells are expected to increase under climate change. The projected transition time of wet to dry compound spells are shorter compared to the historical period, indicating the need for effective water management for the following drought conditions. Projections also show changes in the spatial extent of individual and compound clusters in a changing climate. The results of this study support risk management regarding water, food, and socioeconomic security in the future.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2022
- Bibcode:
- 2022AGUFMNH41A..05N