The Impacts of Urbanization on Daily Precipitation Trends in the Kentucky-Ohio River Valley

This study investigates impacts of urbanization on precipitation around three major urban areas in the Kentucky-Ohio River valley. These metropolitan areas include Cincinnati, Louisville, and Evansville. The warm-season months of June, July, and August were chosen based on, generally, limited frontal forcing on precipitation. Daily data from 1982-2011 were obtained from the Midwest Regional Climate Center's Applied Climate System (MACS) database for 29 stations surrounding these three urbanized areas. These stations were selected based on their location relative to these urban centers and completeness of time series. Detailed statistical analyses were completed to determine urban impacts. A standardized precipitation anomaly analysis was conducted. Based on the results, anomalies were categorized into 4 groups including 1-1.99, 2-2.99, 3-3.99, and ≥ 4. Subsequently, trend analysis was completed for precipitation anomalies for these groups. Initial results indicate that 16 of the 29 stations show a positive trend for the 1-1.99 anomaly category. Initial results also indicate that 17, 17, and 16 of the 29 stations show negative trends for the 2-2.99, 3-3.99, and ≥ 4 anomaly categories respectively. In the future, we will use radar and satellite data to further investigate the impacts of urbanization on precipitation.