Hydrological Intensification Will Increase the Complexity of Water Resource Management. Issue 3 (18th March 2022)

• Record Type: Journal Article
• Authors: Ficklin, Darren L.; Null, Sarah E.; Abatzoglou, John T.; Novick, Kimberly A.; Myers, Daniel T.
• Is Part Of: Earth's future. Volume 10:Issue 3(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-03-18
• Subjects: climate change -- water resources -- hydrology -- precipitation -- evaporative demand; Environmental sciences -- Periodicals; Environmental sciences; Periodicals; 550
• DOI: 10.1029/2021EF002487
• Languages: English
• ISSNs: 2328-4277

Abstract

Abstract: Global warming intensifies the hydrological cycle by altering the rate of water fluxes to and from the terrestrial surface, resulting in an increase in extreme precipitation events and longer dry spells. Prior hydrological intensification work has largely focused on precipitation without joint consideration of evaporative demand changes and how plants respond to these changes. Informed by state‐of‐the‐art climate models, we examine projected changes in hydrological intensification and its role in complicating water resources management using a framework that accounts for precipitation surplus and evaporative demand. Using a metric that combines the difference between daily precipitation and daily evaporative demand (surplus events) and consecutive days when evaporative demand exceeds precipitation (deficit time), we show that, globally, surplus events will become larger (+11.5% and +18.5% for moderate and high emission scenarios, respectively) and the duration between them longer (+5.1%; +9.6%) by the end of the century, with the largest changes in the northern latitudes. The intra‐annual occurrence of these extremes will stress existing water management infrastructure in major river basins, where over one third of years during 2070–2100 under a moderate emissions scenario will be hydrologically intense (large intra‐annual increases in surplus intensity and deficit time), tripling that of the historical baseline. Larger increases in hydrologically intense years are found in basins with large reservoir capacity (e.g., Amazon, Congo, and Danube River Basins), which have significant populations, irrigate considerable farmland, and support threatened and endangered aquatic species. Incorporating flexibility into water resource infrastructure and management will be paramount with continued hydrological intensification. Plain Language Summary: Climate change is intensifying the hydrologic cycle, resulting in an increase in floods and droughts. These changes increase the complexity of water resource management that must balance between releasing water to reduce flood risk and storing water for long periods without precipitation. Using updated climate model projections, we show that the amount of precipitation during events will become larger combined with longer dry periods where the daily evaporative demand exceeds precipitation for much of the Earth's surface. Additionally, for the late 21st century, a large portion of the years will be hydrologically intense in major river basins, resulting in conditions that deviate from those for which infrastructure and management policies were developed. Key Points: Precipitation events are projected to become larger and the duration between these events will be longer Heavily managed river basins in the northern and midlatitudes will experience considerable hydrological intensification Water infrastructure and management will likely be challenged to balance flood protection and water supply among competing water uses