Wavelet analysis of hydrological variables and predictors in the Apalachicola-Chattahoochee-Flint and Alabama-Coosa-Tallapoosa River Basins

Drought prediction is an important tool for water management. In order to improve drought prediction this study identifies cyclical components in temperature and precipitation in the Apalachicola-Chattahoochee-Flint (ACF) and Alabama-Coosa-Tallapoosa (ACT) river basin along with cyclical components of potential predictors. This analysis of predicators is a first step in the creation of a regional predictive drought model. A Standardized Precipitation Evaporation Index (SPEI) model of drought is examined along with the relative contribution of temperature and precipitation to drought in the region.The ACT-ACF provided the regional focus for our study due to the ongoing water conflicts between Georgia, Alabama, and Florida in these river basins. Better drought prediction will aid in water management and planning for this area. Precipitation and temperature data were taken from United States Historical Climatology Network (USHCN) gauges across the area of interest over the time period (1895-2012). Wavelet analysis is used to look for cyclical components in precipitation and temperature as well as related cyclical components in possible predictors. Predictors analyzed for shared cyclical components were: Southern Oscillation Index (SOI), Atlantic Multidecadal Oscillation (AMO), Pacific decadal Oscillation (PDO), North Atlantic Oscillation (NAO), Arctic Oscillation (AO), and Bermuda High Index (BHI). The previously discovered “warming hole” is found in our data and it is suggested that this needs to be removed from any temperature data before it can be used in a predictive model. Our data suggests that the recent warming hole has moderated drought in the ACT-ACF region over the 1960-1990 period.