Spatial and Temporal Variability and Trends of Extreme Precipitation in the Mississippi River Basin, USA

Abstract: Assessing the spatial and temporal variability of precipitation is necessary to solve hydrological and water managements problems. Of particular concerns are the increasing frequency of extreme precipitation events and subsequent impacts due to floods, soil erosion and infrastructure failures. On the other hand, prolonged dry spells also affect several ecosystems services. Critical infrastructure operations such as reservoirs and levees, and agricultural activities are affected by these sequential and compounding events. The Mississippi River Basin in the United States is highly vulnerable to these climatic changes. Changes in climate and especially in rainfall characteristics are likely to have strong impact on the people’s living conditions. For instance, reduced amounts of rainfall or increased dry spells may reduce crop yields and disrupt hydropower generation, river navigation and irrigation supplies. Here, we evaluate the spatial and temporal variability of precipitation using daily records for the period 1988-2017. We use several climate change indices related to precipitation that are developed to capture the frequency and trends in extreme events. Our preliminary results indicate significant increasing amount of annual rainfall as a consequence of increasing of heavy and very heavy rainfall. Results also indicate regions within the Mississippi River Basin towards wet conditions; however, the occurrence of prolonged dry spells are increasing. These contrasting patterns will have impacts on several ecosystem services and pose challenges in managing them. Likewise, the increasing of heavy and very heavy precipitation -enhanced by some oceanic teleconnections- over the Missouri river basin and Northeast Ohio river basin is likely to cause flooding with consequences to levee fault increasing vulnerable populations, risk zones and relocations populations.

Keywords: climate change, precipitation extremes, flooding, water managements