Climate impacts on hydrology in the central United States: Application to forecast capability in the Republican River Basin

For many water users and policy makers, the potential impacts of climate change and their effect on the variability of regional water resources has become a major concern. Better monitoring of water resources requires a thorough understanding of the relationships between hydrologic variability and ocean-atmosphere dynamics. However, finding significant links between climate change and hydrologic variability has been a challenge for scientists. Oceanic indices and teleconnections explained by ocean-atmosphere interactions, including the Southern Oscillation Index (SOI), Multivariate El Niño and Southern Oscillation Index (MEI), Pacific Decadal Oscillation (PDO), North Atlantic Oscillation index (NAO), Atlantic Multidecadal Oscillation (AMO), Pacific/North American index (PNA), and Madden-Julian Oscillation (MJO), have raised significant attention within scientific communities to identify the most prominent climate signal as an indicator of abnormal climate conditions. This study identifies the relationships between these indices and major meteorological and hydrologic events in the central United States on the basis of their severity and spatial and temporal extents during the water years from 1950 to 1988. The Standardized Precipitation Index (SPI) and the Standardized Hydrology Index (SHI) are also utilized to identify regional climate and hydrologic responses to oceanic indices using a multivariate statistical analysis. The utility of the framework is then demonstrated by its application to forecasting seasonal streamflows in the Republican River Basin in southwestern Nebraska.